SlideShare ist ein Scribd-Unternehmen logo
1 von 13
Downloaden Sie, um offline zu lesen
Innovative Systems Design and Engineering                                                        www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

             Design and Fabrication of a Low Cost Fluidized
                                             Bed Reactor
                       Oluleye, A. E. and Ogungbemi, A .A. and Anyaeche*, C.O.
       Department of Industrial and Production Engineering University of Ibadan, Ibadan, Nigeria.
     *E-mail of the corresponding author: osita.anyaeche@mail.ui.edu.ng and 3osyanya@yahoo.com.

Abstract

Many farmers now use the dryer as a part of their normal grain-harvesting system even during wet seasons.
This helps in reducing spoilage. However, most available dryers are expensive to purchase and maintain.
This work therefore is an attempt to develop a simple low cost drying bed that can lead to reduced drying
time. The fluidized bed designed and fabricated in this work consists of the drying column, fluidized plate,
the inlet and outlet unit, the heating unit and the fan. The evaluation considered the drying time and
temperature in achieving quality. The drying efficiency and the amount of moisture reduced per time and
were investigated using rice and wheat with moisture contents of 23% and 33% respectively. The dryer has
shorter drying times and efficiencies of 89% and 90% for rice and wheat respectively.

Keywords: Fluidized Bed, Grain Drying, Low Cost Design.

1. Introduction

Grain drying is now common in many countries. Instead of drying only during very wet harvest seasons,
many farmers now use a dryer as a part of their normal grain-harvesting system. This helps in eliminating
spoilage in storage and improvement on early harvesting. The fluidized beds have been developed for
different physical and chemical operations, such as transportation systems and chemical reaction processes
(Baeyens and Geldart, 1986; Kunii and Levenspiel, 1991).Studies (Baeyens and Geldart, 1986; Kunii and
Levenspiel, 1991) however show that the traditional and some commercial grain dryers consume
considerable time and energy in their operations and available dryers are very expensive. Therefore, there is
the need to develop dryers that would lead to time reduction of grain without compromising efficiency and
also give reduced operating cost (Kunii and Levenspiel, 1991).

In this work an attempt is made to design and construct a low cost fluidized bed reactor that will be used in
the drying of food products and its performance was also evaluated.

2. Overview

The drying process is an operation that aims at a reduction of the moisture content in most products,
industrialized or not, to guarantee their preservation in storage and transport (Keey, 1992). The process of
fluidization with hot air is highly attractive for the drying of powders and wet granular materials. This
technique has been used industrially and is currently quite common in the drying of coarse materials,
pharmaceuticals and food products among other solids in different countries of the world (Aberuagba et al,
2005). The major parts of the fluidized bed reactors are: the fluidization vessel, the solids discharge, dust
separator for the exit gas, the air supply and heat supply.

A fluidized bed is a vessel containing a bed of solid particles, e.g. sand or catalytically active particles, and
a method of introducing gas from below. It is a machine in which a continuous flow of wet granular
material is dried. In this process the air velocity of the drying air is adjusted in such a way that the layer of
product is maintained in a fluidized state (Sripawatakul, 1994).



                                                       24
Innovative Systems Design and Engineering                                                      www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

Uniform processing conditions are achieved by passing a gas (usually air) through a product layer under
controlled velocity conditions to create a fluidized state. Heat may be effectively introduced by heating
surfaces (panels or tubes) immersed in the fluidized layer (Queiroz et al, 2005).

2.1.Some Advantages of Fluidized Bed Reactor

One advantage of using fluidized bed reactor as a dryer is the close control of conditions so that
predetermined amount of free moisture may be left with the solids and to prevent dusting of the product
during subsequent material handling operations (Perry and Green, 1998). Other advantages include:

 • Uniform temperature throughout the material bed by enhanced heat transfer
 • Improved gas-solid contact, which results in faster rate of reaction
 • Uniform product quality from extensive bed mixing and controlled reaction conditions
Fluidized bed technology has been successfully applied to the synthesis of materials via gas-solid or solid-
solid reactions, coating via chemical vapor deposition, calcinations, sintering, thermal decomposition,
thermal treatment, and drying (Harper, 2005).

The disadvantages of fluidized beds are summarized below:
• Bubbling beds of fine particles are difficult to predict and are less efficient,
• Rapid mixing of solids causes non-uniform residence times for continuous flow reactors,
• Particle comminuting (breakup) is common,
• Pipe and vessel walls erode due to collisions by particles.




Figure 1: A typical fluidized bed reactor

Other factors that also affect the performance include: Bed temperature, particle size, fluidization velocity,
bed height, tube location, heat transfer coefficient and pressure drop.

2.2 Design Parameters

A full listing of the terms and notations is presented in appendix 1. The design calculations for this work
are based on the works of Levenspiel (1991), Sripawatakul (1994) and Soponronnarit (1999). Also the use
of the conventional formula for the calculation of the volume (V) and cross sectional area (Ac) of a
cylinder was adopted.. These and other relevant formulae are summarized below:

V = π r 2 h Volume of the reactor                                             1
Ac = πD2 /4 = Cross sectional area (Ac)                                           2

                                                     25
Innovative Systems Design and Engineering                                                     www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

The net gravitational force (∆p) needed in the fluidized vessel that would be exerted on the particles inside
the vessel.
∆p = g ( ρc − ρ g ) (1 − ε ) h                                                   3

The emf is the void fraction at the point of the minimum fluidization. It appears in many of the equations
describing the fluid-bed characteristics.
                                                 0.029            0.021
                                   µ2                   ρg 
emf = 0.586 (ψ )
                         −0.072
                                          3                                  4
                                   ρ gη dp              ρc 
Reynolds number (Re): This is a dimensionless parameter that affects the characteristics of the two
velocities involved in the study i.e. the minimum and the maximum fluidization velocity. This is expressed
             124dpVp
as:   Re =                                                                       5
                 µ
Minimum fluidization velocity (umf): This is the velocity required to begin the fluidization at which the
weight of particles’ gravitational force equals the drag on the particles from the rising gas.
         (ψ dp ) η
                     2
                          emf 3
umf    =                         ,           where ⋅η = g ( ρ c − ρ g )          6
             150 µ       1 − emf
Maximum fluidization velocity (Ut): The maximum fluidization velocity was calculated for the reactor so
as to avoid chaotic situation where the particles will not be blown out of the reactor.
       η dp 2                           1.78 ×10−2η 2 1
Ut =                               =   [             ]3 dp                       8
       18µ                                  ρ gµ
Inlet pipe flow ( f r ): The expression adopted based on Eefisso for calculating different flow rates in a
system (www.eefisso.com, 2007).
      1
 f r = π Pi 2V                                                                   9
      4
Mean residence time (τ): This is the mean time during with which the molecules remain on the surface of
the bed .i.e. the mean time interval between impact and drying (IUPAC Compendium of Chemical
Terminology, 1997 ; Sriparratakul, 1994).
      V
τ=                                                                               10.
      f


3.        Methodology
In this section we give the major components, the design calculations and the fabrication of the fluidized
bed.

3.1       Design Calculations
In this section we present the design parameters of the components of the bed, the design computations and
performance tests carried out on the reactor.
3.1.1 The fluidizing vessel Requirements

The fluidization vessel was designed to have a volume of 100cm3 so as to have a maximum bed height of
200mm (20cm). The height and the diameter chosen for this design were based on the fact that it was being
designed on a small scale which will still bring appreciable outputs, and not to occupy much space when
fully installed.

                                                                    26
Innovative Systems Design and Engineering                                                      www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012


For the volume of the fluidizing chamber the use of the conventional formula         V = π r 2 h for volume
determination was adopted.
V = πr2h =3.142x242 x 56 m3

3.1.2 Cross sectional Area of the reactor (Ac)

The cross sectional area of the empty vessel.
Ac = πD 2r/4 = (3.142 x 48 2) /4 = 1809.79 cm2

3.1.3 Net Gravitational force

The net gravitational force needed in the fluidized vessel bed reactor (dryer that would be exerted on the
particles inside the vessel (Saponronnarit, 1999).

∆p = g(ρc - ρg)(1 - ε) h = 9.81(1.3 – 0.00107)(1. 0.84)24
  = 4.89N/m2

3.1.4 emf for the reactor

The emf for the reactor needed in determining the minimum fluidization velocity for the reactor. This emf
is the void fraction at the point of the minimum fluidization. It appears in many of the equations describing
the fluid-bed characteristics (Saponronnarit, 1999).
is computed thus:
Emf = 0.586(Ψ)-0.072 (µ2/ρgηdp3) 0.029 (ρg/ρc ) 0.021
     = 0.586(0.7)-0.072 ({1.5x10-4}2/(0.00107x12.7295x0.0053) 0.029 (0.0017/ 1.3) 0.021
     = 0.7202
Ψ is the measure of particles not ideal in both shape and roughness (Wei and Yu, 1994). It is calculated by
visualizing a sphere whose volume is equal to the particles and dividing the surface area of the sphere by the
measured surface area of the particle.

3.1.5 Reynolds number

This is a dimensionless parameter that affects the characteristics of the two velocities involved in the study
i.e. the minimum and the maximum fluidization velocity.
Re = (124dpVp)/ µ = (124 x 0.05 x 6.5458 x10 -5) / (1.5x10-4)
    = 2.7
Since the Re is less than 10, it gives the type of flow in the fluidizing vessel as a laminar flow and the type
of maximum fluidizing velocity needed for the system.


3.1.6 Minimum fluidization velocity (umf).

Minimum fluidization velocity: This is the minimum velocity needed to blow the particles of the bed. It is
the velocity required to begin the fluidization at which the weight of particles gravitational force equals the
drag on the particles from the rising gas.
Umf =[(Ψdp) 2 / (150µ)] η [(emf) 3/(1-emf)], where η = g(ρc- ρg) = 12.7295
     =[(0.7x 0.05) 2 / (150 x 1.5x10-4)] 12.7295 [(0.47) 3/(1-0.47)]
     = 0.1357m/s

3.1.7 Maximum fluidization velocity.



                                                      27
Innovative Systems Design and Engineering                                                        www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

The maximum velocity needed for the particles inside the reactor. The maximum fluidization velocity was
calculated for the reactor so as to avoid chaotic situation where the particles will not be blown out of the
reactor. The drag on the particles will surpass the gravitational force on the particle and the particles will be
entrained in the gas.

Since the Re number is less than 10, we use the equation, ut = (ηdp2)/[18µ]
    Thus ut = (ηdp2)/ 18µ = 12.795 x 0.052/(18 x 1.5 x 10-4)
            = 11.78m/s

3.1.8 The inlet pipe

The feed inlet pipe was designed to supply feed at a rate of 1.988m3/min, so as not to create a turbulent
situation or flooding of the reactor. The pipe was attached to the reactor at an angle of 30 degrees. The
expression used in the calculation of the pipe flow rate into the vessel was based on the work of Eefisso for
calculating different flow rates (www.eefisso.com, 2007).
This is given as: f r = 1 π Pi 2V = [3.142 x (1.049)2 x 2.3] /4
                         4
                      = 1.988m3/s

3.1.9 Mean residence time for the chamber.

This is the mean time during with which the molecules remain on the surface of the bed .i.e. the mean time
interval between impact and drying (IUPAC Compendium of Chemical Terminology, 1997; Sriparratakul,
1994).
              τ = v/f = 101.248/1.988
                 = 50.9799s

3.1.10 Pressure drop in the equipment

∆P, the pressure drop across the bed is closely related to drag force,
The pressure drop was calculated based on the work of Jayasuriya and Manrique (2005).
∆Pg = hA∆t
    = h x 0.00165x (413 - 353)
     = 0.099h N/m2

3.1.11 Elutriation of Particles from fluidized bed reactor

The elutriation process causes a decrease in the particle concentration in the column and the concentration
may be empirically modeled by an Arrhenius type expression
 C = Co e− Mt ; where C = concentration at time t Co = the initial concentration M = empirical constant.


3.1.12 Power Requirement.

The power required for setting the designed fluidized bed into operation and the continuation of the
operation was based on the suggestions of (Shott et al., 1975). They suggested horse power requirements
for different types of flow actions and different reactions.




                                                       28
Innovative Systems Design and Engineering                                                    www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

TABLE 1: Suggested Horse Power Requirements (hp/1000gal).

Type of flow       Power requirement             Types of operations
Mild               0.5 – 2                       Mixing, blending
Medium             2–5                           Heat transfer, suspension, gas absorption
Violent            5 – 10                        Reactions, Emulsification,

3.2 Bill of Quantities
The quantities and price of material need for the work are summarized in Table 2.
Table 2: Bill of Quantities
 (a) Construction cost
s/n     Materials                  Specifications        Quantity         Rate (Naira)       Cost (Naira)
1       Mild steel                 G18 1.2×1.2 m         4                4000               16000
2       Mild steel                 G16 1.2×1.2 m         2                3750               7000
3       Hacco pipe                 100×4 m               1                5000               5000
4       Brim plate                 4×4 m                 1                2000               2000
5       Valves                                           2                600                1200
6       Electrode                                        2                1200               2400
7       Electric motor                                   1                8000               8000
8       Bolts and nuts                                   20               30                 600
9       Electrode                                        100              10                 1000
10      Paints                                           1                1850               1850
11      Miscellaneous                                                                        5000
Total                                                                           50,550.00

Adding 10% contingency to the total cost give the total design cost to be 55605 Naira.
Adding 25% margin to the total design cost, the machine can be sold at a price of 69509.25 Naira which is
still cheaper when compared to other commercial dryers of 126,556. Naira.

3.3   Fabrication of the Fluidize Bed

The fabrication of the Fluidize Bed was carried out using the data from the above computations. In addition
to that, the following precaution are taken into consideration.
     a. The fluidization vessel: the vessel was designed to have the capacity of receiving heated fluid (hot
           air) from the heat source and to house the porous disk.
     b. The solid inlet feeders:
     c. Solids discharge
     d. Dust separator for the exit gas: The dust collector is usually designed to trap any solid, which
           might want to escape with the exit gas.
     e. The air supply: the use of an electric motor fan was used to supply air to the system.
     f. Heat supply: the heat was supplied by a heating element at a temperature of 1150 Celsius.


3.4 Performance Tests

Tests were carried out on the designed machine to ascertain its performance. The analysis was carried out
on the fluidization reactor to determine the moisture reduction of rice and wheat during the drying process.

Before the fluidization process, the weights of the rice and wheat were measured. The grains were fed
manually into the equipment and the outputs from the grains outlet were subsequently collected and

                                                    29
Innovative Systems Design and Engineering                                                       www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

weighed. The temperature and pressure were kept constant at the heating chamber throughout the whole
process and the time was varied between ten and thirty minutes for different quantities of food samples.
The temperature inside the chamber was found to be 63 degrees centigrade.

The aim of the experiment was to monitor the reduction of moisture in food grains at different time
intervals and constant temperature using rice and wheat as the samples.

For the evaluation process the following parameters were employed based on the work of Okoli (1991) and
Ojediran and Jekayinfa (2002).

Sample evaluations were done using the following as the guide.
Moisture content in sample (mc) = original weight (Os) less final weight (Fs).
i.e. mc = Os – Fs                                                              12

Drying time for samples
(τ) = (.x1 − xr) / N                                                                13
% moisture content (Mc)

Loss in weight                       × 100
Weight of the original sample
        mc
 Mc =      × 100                                                                    14
        Os

Efficiency of the system (Eff):
1 –Mc = Eff                                                                         15

The results of the tests on the designed fluidized bed reactor were taken at 5 minutes interval to ascertain its
efficiency; and also were compared with those of some commercial dryers. The results and the graphs are
the discussions are presented in section 4.

4.0      Results and Discussion

4.1 Results of Performance Evaluation

Table 3: Percentage Moisture Reduction in Grain Samples

Time (minutes)        Rice (% moisture content reduced)            Wheat (% moisture content reduced)
10                    4.774                                        3.212
15                    4.896                                        5.576
20                    5.682                                        7.114
25                    7.550                                        8.605
30                    8.048                                        9.420
35                    11.178                                       9.670

For the results of efficiency of the designed equipment are presented in table 4.




                                                      30
Innovative Systems Design and Engineering                                                                                                               www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

Table 4: Efficiencies of the Fluid Bed Dryer

Time (minutes)                                                       Rice efficiency                                          Wheat efficiency
10                                                                   0.95                                                     0.97
15                                                                   0.95                                                     0.94
20                                                                   0.94                                                     0.93
25                                                                   0.92                                                     0.91
30                                                                   0.92                                                     0.91
35                                                                   0.89                                                     0.90

Table 5: Performance Test Results Of Commercial Dryers At 20 Minutes

Drying           air Inlet moisture of                                         Outlet moisture of               Moisture reduction in grain
temperature (oC)       grain (%)                                               grain (%)                        (%)
115                    22.0                                                    20.1                             1.9
115                    26.0                                                    22.5                             3.5
115                    28.7                                                    22.5                             6.2
115                    30.6                                                    23.0                             7.6
115                    27.0                                                    21.0                             6.0
Source: Soponronnarit (1999).

                                                                                                                                              R ic e
                                       2 6                                                                                                    W h e a t




                                                                                                                                                      R ic e
                                                                                                                                                      W h e a t
       weight of samples




                                        0 .9 8

                                        0 .9 7

                                        0 .9 6

                                        0 .9 5
                                       2 4
                  % moisture content




                                        0 .9 4

                                        0 .9 3

                                        0 .9 2

                                        0 .9 1
                                             8   1 0   1 2   1 4   1 6   1 8     2 0      2 2      2 4    2 6     2 8    3 0     3 2    3 4     3 6

                                        0 .9 0                                 tim e     ( m in u te s )

                                        0 .8 9


Figure 2: Weight 8of samples 2 1 4 time.
                       1 0 1
                             against 1 6                                       1 8      2 0     2 2      2 4    2 6     2 8     3 0    3 2     3 4      3 6
                                                                                       tim e    ( m in u te s )



An examination of figure 2 shows that as the time in increased the moisture content in particles and their
corresponding weights decreases because the moisture content contributed to the total weight of the
particles. This shows that the fluidized bed dyer is a good medium for drying of rice and wheat.




                                                                                              31
Innovative Systems Design and Engineering                                                                                                          www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012


                                                                                                                                          R ic e

                                                         36
                                                         34
                                                         32
                                                         30
                                                         28
                                 drying time (minutes)




                                                         26
                                                         24
                                                         22
                                                         20
                                                         18
                                                         16
                                                         14
                                                         12
                                                         10
                                                             8
                                                                 4        6                          8                      10                 12
                                                                               m o is t u r e c o n t e n t r e d u c e d
     F ig u r e 4 . 3 G r a p h o f d r y in g t im e a g a in s t t h e p e r c e n t a g e m o is t u r e c o n t e n t r e d u c e d in r ic e


Fig 3: Drying time against Percentage moisture content in rice.

                                                                                                                                 W heat

                                                   36
                                                   34
                                                   32
                                                   30
                                                   28
              drying time (minutes)




                                                   26
                                                   24
                                                   22
                                                   20
                                                   18
                                                   16
                                                   14
                                                   12
                                                   10
                                                         8
                                                             4       6                      8                       10              12
                                                                         m o is tu r e c o n te n t r e d u c e d
    F ig u r e 4 . 4 G r a p h o f d r y i n g t im e a g a in s t t h e p e r c e n t a g e m o is t u r e c o n t e n t r e d u c e d in w h e a t


Fig 4: Drying time verses %age moisture in wheat

Figures 3 and 4 show the conformity of the fluidized bed dryer to the different drying principles in the
literature. As the time is increased so also the moisture reduced until it gets to the equilibrium stage where
no moisture will be removed from the grains. Wheat shows a better curve than rice since they are smaller in
size and weight than rice. This is probably because the smaller seeds or grains have higher resistance to
airflow and therefore reducing the action on fan outputs.




                                                                                                32
Innovative Systems Design and Engineering                                                              www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012


                                                                                             B



                                   8
              % moisture reduced




                                   6




                                   4




                                   2



                                       110   115   120   125   130   135   140   145   150       155
                                      temperature degree
    Figure 4.5 graph of%moisture reduced in commercial fluidized bed dryer against temperature at 20minutes



Fig 5: Percentage of moisture Commercial fluidized bed against Temperature (20 min)


Figure 5 shows the amount of moisture reduced at different temperatures at the time of 20 minutes.
Comparing the efficiencies at the temperature of 115 degrees centigrade and at 20 minutes with the
designed fluidized bed dryer, it was seen that the efficiencies is lower when compared with the designed
dryer.

5.1 Conclusions
In this work the design and fabrication procedure for a low cost fluidized bed has been demonstrated. From
the results obtained, it can be inferred that the weights of different samples affect the fluidization process,
because grains with higher weights show less resistance to air flow in the system.

In addition to that, increasing the airflow speed increases the drying rate but also increases the power
consumption in the system, smaller grains show high resistance to airflow therefore reducing the fan
outputs and also increasing the amount of moisture reduced in the grains by the hot air giving higher power
efficiency in wheat than in rice.

A fluidized bed dryer can be competitive with other convectional drying methods especially at high
moisture level and low energy consumption. Drying on fluidized bed is a reliable and economical method
for drying of light weighted grains.

Further work may investigate the energy consumption. Further research should be carried out on other food
grains that have different weights and moisture content than the rice and wheat used in this study.

References:

Baeyens, J. and Geldart, D., Gas Fluidization Technology, Wiley, London, chapter Solids
mixing, p 79–86 (1986).

Kunii, D., and Levenspiel, O., (1991), Fluidization Engineering 2nd edition. Butterworth-Heinemann
Corporation.

                                                                           33
Innovative Systems Design and Engineering                                                      www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012


Keey, R. B., (1992) Drying of Loose and Particulate Materials, New York: Hemishere Publishers, p 29-32.

Aberuagba. F, Odigure. J. O, Adeboye .K. R, and Olutoye. M. A, (2005), Fluidization Characteristics of a
Prototype Fluidized Bed Reactor, Leonardo Journal of Sciences.

Sripawatakul, O.,(1994), Study of drying Paddy by Cross-Flow Fluidization Technique, Master thesis,
Faculty of Engineering, King Mongkutis Institute of Technology, Thonburi, Bangkok, Thailand.

Queiroz, C.A.R., Carvalho, R.J, and Moura, F. J. (2005), Oxidation of zinc sulphide concentrate in a
fluidized bed reactor-part 1: characterization of the fluid dynamics of the particle bed”, Brazilian journal of
chemical engineering, vol 22, number 01, p 117-125 (Jan-March, 2005).

Soponronnarit, S. , (1999), Fluidized-Bed paddy Drying, Science Asia Journal 25, p 51-56.

Eefisso company, www.eefisso.com, (April, 2007).

IUPAC Compendium of Chemical Terminology, (1997).

Wen, C.Y., and Yu,Y.H.,(1994), AIChE J., 12, 610. (1994).

Jayasuriya. J and Marique. A, (2005), laboratory notes on heat transfer measurement in fluidized bed
combustion reactor, Stockholm, (3- Feb-2005).

Shott, N.R, Weinstein, B and LaBombard, D., (1975), Motionless Mixers in Plastic Processing, Chem Eng.
Prog, Vol 71, No 1.

Okoli, J.U. (1991), Some Factors Affecting the Efficiency of Locally Fabricated Palm Kennel/Shell Nut
Crackers, NIIE Annual Conference, Ibadan.

Ojediran, J.O and Jekayinfa. S.O, (2002), Performance Evaluation of a Centrifugal Palm Nut Cracker,
Journal of Applied Science and Technology, Ibadan.

NOTATIONS
Here we define the notations used in this work.
τ = drying time (seconds)
X1= initial moisture (kgh20kg-1.d.m)
xr = relative moisture (kgh20kg-1.d.m)
N = drying velocity (kgh20kg-1.d.m)
υ = velocity (ms-1)
υ1 = minimal fluidization speed (ms-1)
m.d.m = dry matter, mass (kg)
β = dimensionless coefficient
ρ = density (kg-3)
ρ1 = bulk density (kg-3)
Wost = water content in fresh material. (Kg/kg)
A = heating element area
D= Reactor diameter
H= Reactor height
P= Pressure
V= Air velocity
ε = porosity

                                                      34
Innovative Systems Design and Engineering        www.iiste.org
ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online)
Vol 3, No 3, 2012

g = Acceleration due to gravity
π = pi
ρg = 1.07× 10-3g/cm3
ψ = 0.7
µ = 1.5×10-4 poise
h = Bed height
Vp = Particle diameter
Pi = Pipe Diameter
Umf = minimum fluidization velocity
Ut = maximum fluidization velocity
Mc = % moisture content
Mc = moisture content
Ac = cross sectional area
V = volume




Plate 1: Constructed fluidized bed dryer.




                                            35
International Journals Call for Paper
The IISTE, a U.S. publisher, is currently hosting the academic journals listed below. The peer review process of the following journals
usually takes LESS THAN 14 business days and IISTE usually publishes a qualified article within 30 days. Authors should
send their full paper to the following email address. More information can be found in the IISTE website : www.iiste.org

Business, Economics, Finance and Management               PAPER SUBMISSION EMAIL
European Journal of Business and Management               EJBM@iiste.org
Research Journal of Finance and Accounting                RJFA@iiste.org
Journal of Economics and Sustainable Development          JESD@iiste.org
Information and Knowledge Management                      IKM@iiste.org
Developing Country Studies                                DCS@iiste.org
Industrial Engineering Letters                            IEL@iiste.org


Physical Sciences, Mathematics and Chemistry              PAPER SUBMISSION EMAIL
Journal of Natural Sciences Research                      JNSR@iiste.org
Chemistry and Materials Research                          CMR@iiste.org
Mathematical Theory and Modeling                          MTM@iiste.org
Advances in Physics Theories and Applications             APTA@iiste.org
Chemical and Process Engineering Research                 CPER@iiste.org


Engineering, Technology and Systems                       PAPER SUBMISSION EMAIL
Computer Engineering and Intelligent Systems              CEIS@iiste.org
Innovative Systems Design and Engineering                 ISDE@iiste.org
Journal of Energy Technologies and Policy                 JETP@iiste.org
Information and Knowledge Management                      IKM@iiste.org
Control Theory and Informatics                            CTI@iiste.org
Journal of Information Engineering and Applications       JIEA@iiste.org
Industrial Engineering Letters                            IEL@iiste.org
Network and Complex Systems                               NCS@iiste.org


Environment, Civil, Materials Sciences                    PAPER SUBMISSION EMAIL
Journal of Environment and Earth Science                  JEES@iiste.org
Civil and Environmental Research                          CER@iiste.org
Journal of Natural Sciences Research                      JNSR@iiste.org
Civil and Environmental Research                          CER@iiste.org


Life Science, Food and Medical Sciences                   PAPER SUBMISSION EMAIL
Journal of Natural Sciences Research                      JNSR@iiste.org
Journal of Biology, Agriculture and Healthcare            JBAH@iiste.org
Food Science and Quality Management                       FSQM@iiste.org
Chemistry and Materials Research                          CMR@iiste.org


Education, and other Social Sciences                      PAPER SUBMISSION EMAIL
Journal of Education and Practice                         JEP@iiste.org
Journal of Law, Policy and Globalization                  JLPG@iiste.org                       Global knowledge sharing:
New Media and Mass Communication                          NMMC@iiste.org                       EBSCO, Index Copernicus, Ulrich's
Journal of Energy Technologies and Policy                 JETP@iiste.org                       Periodicals Directory, JournalTOCS, PKP
Historical Research Letter                                HRL@iiste.org                        Open Archives Harvester, Bielefeld
                                                                                               Academic Search Engine, Elektronische
Public Policy and Administration Research                 PPAR@iiste.org                       Zeitschriftenbibliothek EZB, Open J-Gate,
International Affairs and Global Strategy                 IAGS@iiste.org                       OCLC WorldCat, Universe Digtial Library ,
Research on Humanities and Social Sciences                RHSS@iiste.org                       NewJour, Google Scholar.

Developing Country Studies                                DCS@iiste.org                        IISTE is member of CrossRef. All journals
Arts and Design Studies                                   ADS@iiste.org                        have high IC Impact Factor Values (ICV).

Weitere ähnliche Inhalte

Ähnlich wie 11.design and fabrication of a low cost fluidized

Calculation guidelines for Rotary Dryer.pdf
Calculation guidelines for Rotary Dryer.pdfCalculation guidelines for Rotary Dryer.pdf
Calculation guidelines for Rotary Dryer.pdfEd Ryan Ruales
 
Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...
Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...
Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...drboon
 
Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...
Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...
Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...IJERA Editor
 
Cyclones
CyclonesCyclones
Cyclonesahkiaen
 
THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...
THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...
THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...IAEME Publication
 
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...IAEME Publication
 
An experimental study of forced convection green house dry 2
An experimental study of forced convection green house dry 2An experimental study of forced convection green house dry 2
An experimental study of forced convection green house dry 2IAEME Publication
 
Membrane distillation
Membrane distillationMembrane distillation
Membrane distillationKimia Store
 
Membrane distillation
Membrane distillationMembrane distillation
Membrane distillationYahia Reda
 
Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...
Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...
Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...IJERA Editor
 
j.1365-2621.2004.00886.x.pdf
j.1365-2621.2004.00886.x.pdfj.1365-2621.2004.00886.x.pdf
j.1365-2621.2004.00886.x.pdfRajuRamaiah2
 
Optimization of Air Preheater for compactness of shell by evaluating performa...
Optimization of Air Preheater for compactness of shell by evaluating performa...Optimization of Air Preheater for compactness of shell by evaluating performa...
Optimization of Air Preheater for compactness of shell by evaluating performa...Nemish Kanwar
 
Performance Analysis of Forced Convection Solar Dryer for Turmeric
Performance Analysis of Forced Convection Solar Dryer for TurmericPerformance Analysis of Forced Convection Solar Dryer for Turmeric
Performance Analysis of Forced Convection Solar Dryer for TurmericIRJET Journal
 
Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...
Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...
Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...RSIS International
 

Ähnlich wie 11.design and fabrication of a low cost fluidized (20)

Rotary dryer
Rotary dryerRotary dryer
Rotary dryer
 
Calculation guidelines for Rotary Dryer.pdf
Calculation guidelines for Rotary Dryer.pdfCalculation guidelines for Rotary Dryer.pdf
Calculation guidelines for Rotary Dryer.pdf
 
Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...
Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...
Effective Moisture Diffusivity and Activation Energy of Tomato in Thin Layer ...
 
Ge3510911102
Ge3510911102Ge3510911102
Ge3510911102
 
Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...
Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...
Theoretical Convective Heat Transfer Model Developement of Cold Storage Using...
 
H046034353
H046034353H046034353
H046034353
 
Cyclones
CyclonesCyclones
Cyclones
 
THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...
THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...
THERMODYNAMIC SIMULATION OF YEAR ROUND AIR CONDITIONING SYSTEM FOR VARIABLE R...
 
4.pdf
4.pdf4.pdf
4.pdf
 
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...
NUMERICAL INVESTIGATION OF NATURAL CONVECTION HEAT TRANSFER FROM CIRCULAR CYL...
 
An experimental study of forced convection green house dry 2
An experimental study of forced convection green house dry 2An experimental study of forced convection green house dry 2
An experimental study of forced convection green house dry 2
 
Membrane distillation
Membrane distillationMembrane distillation
Membrane distillation
 
Membrane distillation
Membrane distillationMembrane distillation
Membrane distillation
 
Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...
Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...
Optimization of “T”-Shaped Fins Geometry Using Constructal Theory and “FEA” C...
 
j.1365-2621.2004.00886.x.pdf
j.1365-2621.2004.00886.x.pdfj.1365-2621.2004.00886.x.pdf
j.1365-2621.2004.00886.x.pdf
 
Optimization of Air Preheater for compactness of shell by evaluating performa...
Optimization of Air Preheater for compactness of shell by evaluating performa...Optimization of Air Preheater for compactness of shell by evaluating performa...
Optimization of Air Preheater for compactness of shell by evaluating performa...
 
Ijetae 0413 59
Ijetae 0413 59Ijetae 0413 59
Ijetae 0413 59
 
Performance Analysis of Forced Convection Solar Dryer for Turmeric
Performance Analysis of Forced Convection Solar Dryer for TurmericPerformance Analysis of Forced Convection Solar Dryer for Turmeric
Performance Analysis of Forced Convection Solar Dryer for Turmeric
 
Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...
Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...
Numerical Simulation of Solar Greenhouse Dryer Using Computational Fluid Dyna...
 
30120140506010 2
30120140506010 230120140506010 2
30120140506010 2
 

Mehr von Alexander Decker

Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...Alexander Decker
 
A validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale inA validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale inAlexander Decker
 
A usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websitesA usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websitesAlexander Decker
 
A universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banksA universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banksAlexander Decker
 
A unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized dA unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized dAlexander Decker
 
A trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistanceA trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistanceAlexander Decker
 
A transformational generative approach towards understanding al-istifham
A transformational  generative approach towards understanding al-istifhamA transformational  generative approach towards understanding al-istifham
A transformational generative approach towards understanding al-istifhamAlexander Decker
 
A time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibiaA time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibiaAlexander Decker
 
A therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school childrenA therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school childrenAlexander Decker
 
A theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banksA theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banksAlexander Decker
 
A systematic evaluation of link budget for
A systematic evaluation of link budget forA systematic evaluation of link budget for
A systematic evaluation of link budget forAlexander Decker
 
A synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjabA synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjabAlexander Decker
 
A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...Alexander Decker
 
A survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incrementalA survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incrementalAlexander Decker
 
A survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniquesA survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniquesAlexander Decker
 
A survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo dbA survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo dbAlexander Decker
 
A survey on challenges to the media cloud
A survey on challenges to the media cloudA survey on challenges to the media cloud
A survey on challenges to the media cloudAlexander Decker
 
A survey of provenance leveraged
A survey of provenance leveragedA survey of provenance leveraged
A survey of provenance leveragedAlexander Decker
 
A survey of private equity investments in kenya
A survey of private equity investments in kenyaA survey of private equity investments in kenya
A survey of private equity investments in kenyaAlexander Decker
 
A study to measures the financial health of
A study to measures the financial health ofA study to measures the financial health of
A study to measures the financial health ofAlexander Decker
 

Mehr von Alexander Decker (20)

Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...Abnormalities of hormones and inflammatory cytokines in women affected with p...
Abnormalities of hormones and inflammatory cytokines in women affected with p...
 
A validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale inA validation of the adverse childhood experiences scale in
A validation of the adverse childhood experiences scale in
 
A usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websitesA usability evaluation framework for b2 c e commerce websites
A usability evaluation framework for b2 c e commerce websites
 
A universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banksA universal model for managing the marketing executives in nigerian banks
A universal model for managing the marketing executives in nigerian banks
 
A unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized dA unique common fixed point theorems in generalized d
A unique common fixed point theorems in generalized d
 
A trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistanceA trends of salmonella and antibiotic resistance
A trends of salmonella and antibiotic resistance
 
A transformational generative approach towards understanding al-istifham
A transformational  generative approach towards understanding al-istifhamA transformational  generative approach towards understanding al-istifham
A transformational generative approach towards understanding al-istifham
 
A time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibiaA time series analysis of the determinants of savings in namibia
A time series analysis of the determinants of savings in namibia
 
A therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school childrenA therapy for physical and mental fitness of school children
A therapy for physical and mental fitness of school children
 
A theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banksA theory of efficiency for managing the marketing executives in nigerian banks
A theory of efficiency for managing the marketing executives in nigerian banks
 
A systematic evaluation of link budget for
A systematic evaluation of link budget forA systematic evaluation of link budget for
A systematic evaluation of link budget for
 
A synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjabA synthetic review of contraceptive supplies in punjab
A synthetic review of contraceptive supplies in punjab
 
A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...A synthesis of taylor’s and fayol’s management approaches for managing market...
A synthesis of taylor’s and fayol’s management approaches for managing market...
 
A survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incrementalA survey paper on sequence pattern mining with incremental
A survey paper on sequence pattern mining with incremental
 
A survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniquesA survey on live virtual machine migrations and its techniques
A survey on live virtual machine migrations and its techniques
 
A survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo dbA survey on data mining and analysis in hadoop and mongo db
A survey on data mining and analysis in hadoop and mongo db
 
A survey on challenges to the media cloud
A survey on challenges to the media cloudA survey on challenges to the media cloud
A survey on challenges to the media cloud
 
A survey of provenance leveraged
A survey of provenance leveragedA survey of provenance leveraged
A survey of provenance leveraged
 
A survey of private equity investments in kenya
A survey of private equity investments in kenyaA survey of private equity investments in kenya
A survey of private equity investments in kenya
 
A study to measures the financial health of
A study to measures the financial health ofA study to measures the financial health of
A study to measures the financial health of
 

Kürzlich hochgeladen

[BuildWithAI] Introduction to Gemini.pdf
[BuildWithAI] Introduction to Gemini.pdf[BuildWithAI] Introduction to Gemini.pdf
[BuildWithAI] Introduction to Gemini.pdfSandro Moreira
 
Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...
Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...
Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...apidays
 
Mcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot Model
Mcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot ModelMcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot Model
Mcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot ModelDeepika Singh
 
Strategize a Smooth Tenant-to-tenant Migration and Copilot Takeoff
Strategize a Smooth Tenant-to-tenant Migration and Copilot TakeoffStrategize a Smooth Tenant-to-tenant Migration and Copilot Takeoff
Strategize a Smooth Tenant-to-tenant Migration and Copilot Takeoffsammart93
 
MINDCTI Revenue Release Quarter One 2024
MINDCTI Revenue Release Quarter One 2024MINDCTI Revenue Release Quarter One 2024
MINDCTI Revenue Release Quarter One 2024MIND CTI
 
"I see eyes in my soup": How Delivery Hero implemented the safety system for ...
"I see eyes in my soup": How Delivery Hero implemented the safety system for ..."I see eyes in my soup": How Delivery Hero implemented the safety system for ...
"I see eyes in my soup": How Delivery Hero implemented the safety system for ...Zilliz
 
Platformless Horizons for Digital Adaptability
Platformless Horizons for Digital AdaptabilityPlatformless Horizons for Digital Adaptability
Platformless Horizons for Digital AdaptabilityWSO2
 
Corporate and higher education May webinar.pptx
Corporate and higher education May webinar.pptxCorporate and higher education May webinar.pptx
Corporate and higher education May webinar.pptxRustici Software
 
Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...
Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...
Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...Orbitshub
 
ICT role in 21st century education and its challenges
ICT role in 21st century education and its challengesICT role in 21st century education and its challenges
ICT role in 21st century education and its challengesrafiqahmad00786416
 
TrustArc Webinar - Unlock the Power of AI-Driven Data Discovery
TrustArc Webinar - Unlock the Power of AI-Driven Data DiscoveryTrustArc Webinar - Unlock the Power of AI-Driven Data Discovery
TrustArc Webinar - Unlock the Power of AI-Driven Data DiscoveryTrustArc
 
Elevate Developer Efficiency & build GenAI Application with Amazon Q​
Elevate Developer Efficiency & build GenAI Application with Amazon Q​Elevate Developer Efficiency & build GenAI Application with Amazon Q​
Elevate Developer Efficiency & build GenAI Application with Amazon Q​Bhuvaneswari Subramani
 
Finding Java's Hidden Performance Traps @ DevoxxUK 2024
Finding Java's Hidden Performance Traps @ DevoxxUK 2024Finding Java's Hidden Performance Traps @ DevoxxUK 2024
Finding Java's Hidden Performance Traps @ DevoxxUK 2024Victor Rentea
 
How to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected WorkerHow to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected WorkerThousandEyes
 
Introduction to Multilingual Retrieval Augmented Generation (RAG)
Introduction to Multilingual Retrieval Augmented Generation (RAG)Introduction to Multilingual Retrieval Augmented Generation (RAG)
Introduction to Multilingual Retrieval Augmented Generation (RAG)Zilliz
 
Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...
Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...
Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...Angeliki Cooney
 
Rising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdf
Rising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdfRising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdf
Rising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdfOrbitshub
 
Boost Fertility New Invention Ups Success Rates.pdf
Boost Fertility New Invention Ups Success Rates.pdfBoost Fertility New Invention Ups Success Rates.pdf
Boost Fertility New Invention Ups Success Rates.pdfsudhanshuwaghmare1
 
Apidays New York 2024 - The value of a flexible API Management solution for O...
Apidays New York 2024 - The value of a flexible API Management solution for O...Apidays New York 2024 - The value of a flexible API Management solution for O...
Apidays New York 2024 - The value of a flexible API Management solution for O...apidays
 
presentation ICT roal in 21st century education
presentation ICT roal in 21st century educationpresentation ICT roal in 21st century education
presentation ICT roal in 21st century educationjfdjdjcjdnsjd
 

Kürzlich hochgeladen (20)

[BuildWithAI] Introduction to Gemini.pdf
[BuildWithAI] Introduction to Gemini.pdf[BuildWithAI] Introduction to Gemini.pdf
[BuildWithAI] Introduction to Gemini.pdf
 
Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...
Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...
Apidays New York 2024 - The Good, the Bad and the Governed by David O'Neill, ...
 
Mcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot Model
Mcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot ModelMcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot Model
Mcleodganj Call Girls 🥰 8617370543 Service Offer VIP Hot Model
 
Strategize a Smooth Tenant-to-tenant Migration and Copilot Takeoff
Strategize a Smooth Tenant-to-tenant Migration and Copilot TakeoffStrategize a Smooth Tenant-to-tenant Migration and Copilot Takeoff
Strategize a Smooth Tenant-to-tenant Migration and Copilot Takeoff
 
MINDCTI Revenue Release Quarter One 2024
MINDCTI Revenue Release Quarter One 2024MINDCTI Revenue Release Quarter One 2024
MINDCTI Revenue Release Quarter One 2024
 
"I see eyes in my soup": How Delivery Hero implemented the safety system for ...
"I see eyes in my soup": How Delivery Hero implemented the safety system for ..."I see eyes in my soup": How Delivery Hero implemented the safety system for ...
"I see eyes in my soup": How Delivery Hero implemented the safety system for ...
 
Platformless Horizons for Digital Adaptability
Platformless Horizons for Digital AdaptabilityPlatformless Horizons for Digital Adaptability
Platformless Horizons for Digital Adaptability
 
Corporate and higher education May webinar.pptx
Corporate and higher education May webinar.pptxCorporate and higher education May webinar.pptx
Corporate and higher education May webinar.pptx
 
Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...
Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...
Navigating the Deluge_ Dubai Floods and the Resilience of Dubai International...
 
ICT role in 21st century education and its challenges
ICT role in 21st century education and its challengesICT role in 21st century education and its challenges
ICT role in 21st century education and its challenges
 
TrustArc Webinar - Unlock the Power of AI-Driven Data Discovery
TrustArc Webinar - Unlock the Power of AI-Driven Data DiscoveryTrustArc Webinar - Unlock the Power of AI-Driven Data Discovery
TrustArc Webinar - Unlock the Power of AI-Driven Data Discovery
 
Elevate Developer Efficiency & build GenAI Application with Amazon Q​
Elevate Developer Efficiency & build GenAI Application with Amazon Q​Elevate Developer Efficiency & build GenAI Application with Amazon Q​
Elevate Developer Efficiency & build GenAI Application with Amazon Q​
 
Finding Java's Hidden Performance Traps @ DevoxxUK 2024
Finding Java's Hidden Performance Traps @ DevoxxUK 2024Finding Java's Hidden Performance Traps @ DevoxxUK 2024
Finding Java's Hidden Performance Traps @ DevoxxUK 2024
 
How to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected WorkerHow to Troubleshoot Apps for the Modern Connected Worker
How to Troubleshoot Apps for the Modern Connected Worker
 
Introduction to Multilingual Retrieval Augmented Generation (RAG)
Introduction to Multilingual Retrieval Augmented Generation (RAG)Introduction to Multilingual Retrieval Augmented Generation (RAG)
Introduction to Multilingual Retrieval Augmented Generation (RAG)
 
Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...
Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...
Biography Of Angeliki Cooney | Senior Vice President Life Sciences | Albany, ...
 
Rising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdf
Rising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdfRising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdf
Rising Above_ Dubai Floods and the Fortitude of Dubai International Airport.pdf
 
Boost Fertility New Invention Ups Success Rates.pdf
Boost Fertility New Invention Ups Success Rates.pdfBoost Fertility New Invention Ups Success Rates.pdf
Boost Fertility New Invention Ups Success Rates.pdf
 
Apidays New York 2024 - The value of a flexible API Management solution for O...
Apidays New York 2024 - The value of a flexible API Management solution for O...Apidays New York 2024 - The value of a flexible API Management solution for O...
Apidays New York 2024 - The value of a flexible API Management solution for O...
 
presentation ICT roal in 21st century education
presentation ICT roal in 21st century educationpresentation ICT roal in 21st century education
presentation ICT roal in 21st century education
 

11.design and fabrication of a low cost fluidized

  • 1. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 Design and Fabrication of a Low Cost Fluidized Bed Reactor Oluleye, A. E. and Ogungbemi, A .A. and Anyaeche*, C.O. Department of Industrial and Production Engineering University of Ibadan, Ibadan, Nigeria. *E-mail of the corresponding author: osita.anyaeche@mail.ui.edu.ng and 3osyanya@yahoo.com. Abstract Many farmers now use the dryer as a part of their normal grain-harvesting system even during wet seasons. This helps in reducing spoilage. However, most available dryers are expensive to purchase and maintain. This work therefore is an attempt to develop a simple low cost drying bed that can lead to reduced drying time. The fluidized bed designed and fabricated in this work consists of the drying column, fluidized plate, the inlet and outlet unit, the heating unit and the fan. The evaluation considered the drying time and temperature in achieving quality. The drying efficiency and the amount of moisture reduced per time and were investigated using rice and wheat with moisture contents of 23% and 33% respectively. The dryer has shorter drying times and efficiencies of 89% and 90% for rice and wheat respectively. Keywords: Fluidized Bed, Grain Drying, Low Cost Design. 1. Introduction Grain drying is now common in many countries. Instead of drying only during very wet harvest seasons, many farmers now use a dryer as a part of their normal grain-harvesting system. This helps in eliminating spoilage in storage and improvement on early harvesting. The fluidized beds have been developed for different physical and chemical operations, such as transportation systems and chemical reaction processes (Baeyens and Geldart, 1986; Kunii and Levenspiel, 1991).Studies (Baeyens and Geldart, 1986; Kunii and Levenspiel, 1991) however show that the traditional and some commercial grain dryers consume considerable time and energy in their operations and available dryers are very expensive. Therefore, there is the need to develop dryers that would lead to time reduction of grain without compromising efficiency and also give reduced operating cost (Kunii and Levenspiel, 1991). In this work an attempt is made to design and construct a low cost fluidized bed reactor that will be used in the drying of food products and its performance was also evaluated. 2. Overview The drying process is an operation that aims at a reduction of the moisture content in most products, industrialized or not, to guarantee their preservation in storage and transport (Keey, 1992). The process of fluidization with hot air is highly attractive for the drying of powders and wet granular materials. This technique has been used industrially and is currently quite common in the drying of coarse materials, pharmaceuticals and food products among other solids in different countries of the world (Aberuagba et al, 2005). The major parts of the fluidized bed reactors are: the fluidization vessel, the solids discharge, dust separator for the exit gas, the air supply and heat supply. A fluidized bed is a vessel containing a bed of solid particles, e.g. sand or catalytically active particles, and a method of introducing gas from below. It is a machine in which a continuous flow of wet granular material is dried. In this process the air velocity of the drying air is adjusted in such a way that the layer of product is maintained in a fluidized state (Sripawatakul, 1994). 24
  • 2. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 Uniform processing conditions are achieved by passing a gas (usually air) through a product layer under controlled velocity conditions to create a fluidized state. Heat may be effectively introduced by heating surfaces (panels or tubes) immersed in the fluidized layer (Queiroz et al, 2005). 2.1.Some Advantages of Fluidized Bed Reactor One advantage of using fluidized bed reactor as a dryer is the close control of conditions so that predetermined amount of free moisture may be left with the solids and to prevent dusting of the product during subsequent material handling operations (Perry and Green, 1998). Other advantages include: • Uniform temperature throughout the material bed by enhanced heat transfer • Improved gas-solid contact, which results in faster rate of reaction • Uniform product quality from extensive bed mixing and controlled reaction conditions Fluidized bed technology has been successfully applied to the synthesis of materials via gas-solid or solid- solid reactions, coating via chemical vapor deposition, calcinations, sintering, thermal decomposition, thermal treatment, and drying (Harper, 2005). The disadvantages of fluidized beds are summarized below: • Bubbling beds of fine particles are difficult to predict and are less efficient, • Rapid mixing of solids causes non-uniform residence times for continuous flow reactors, • Particle comminuting (breakup) is common, • Pipe and vessel walls erode due to collisions by particles. Figure 1: A typical fluidized bed reactor Other factors that also affect the performance include: Bed temperature, particle size, fluidization velocity, bed height, tube location, heat transfer coefficient and pressure drop. 2.2 Design Parameters A full listing of the terms and notations is presented in appendix 1. The design calculations for this work are based on the works of Levenspiel (1991), Sripawatakul (1994) and Soponronnarit (1999). Also the use of the conventional formula for the calculation of the volume (V) and cross sectional area (Ac) of a cylinder was adopted.. These and other relevant formulae are summarized below: V = π r 2 h Volume of the reactor 1 Ac = πD2 /4 = Cross sectional area (Ac) 2 25
  • 3. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 The net gravitational force (∆p) needed in the fluidized vessel that would be exerted on the particles inside the vessel. ∆p = g ( ρc − ρ g ) (1 − ε ) h 3 The emf is the void fraction at the point of the minimum fluidization. It appears in many of the equations describing the fluid-bed characteristics. 0.029 0.021  µ2   ρg  emf = 0.586 (ψ ) −0.072  3    4  ρ gη dp   ρc  Reynolds number (Re): This is a dimensionless parameter that affects the characteristics of the two velocities involved in the study i.e. the minimum and the maximum fluidization velocity. This is expressed 124dpVp as: Re = 5 µ Minimum fluidization velocity (umf): This is the velocity required to begin the fluidization at which the weight of particles’ gravitational force equals the drag on the particles from the rising gas. (ψ dp ) η 2 emf 3 umf = , where ⋅η = g ( ρ c − ρ g ) 6 150 µ 1 − emf Maximum fluidization velocity (Ut): The maximum fluidization velocity was calculated for the reactor so as to avoid chaotic situation where the particles will not be blown out of the reactor. η dp 2 1.78 ×10−2η 2 1 Ut = = [ ]3 dp 8 18µ ρ gµ Inlet pipe flow ( f r ): The expression adopted based on Eefisso for calculating different flow rates in a system (www.eefisso.com, 2007). 1 f r = π Pi 2V 9 4 Mean residence time (τ): This is the mean time during with which the molecules remain on the surface of the bed .i.e. the mean time interval between impact and drying (IUPAC Compendium of Chemical Terminology, 1997 ; Sriparratakul, 1994). V τ= 10. f 3. Methodology In this section we give the major components, the design calculations and the fabrication of the fluidized bed. 3.1 Design Calculations In this section we present the design parameters of the components of the bed, the design computations and performance tests carried out on the reactor. 3.1.1 The fluidizing vessel Requirements The fluidization vessel was designed to have a volume of 100cm3 so as to have a maximum bed height of 200mm (20cm). The height and the diameter chosen for this design were based on the fact that it was being designed on a small scale which will still bring appreciable outputs, and not to occupy much space when fully installed. 26
  • 4. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 For the volume of the fluidizing chamber the use of the conventional formula V = π r 2 h for volume determination was adopted. V = πr2h =3.142x242 x 56 m3 3.1.2 Cross sectional Area of the reactor (Ac) The cross sectional area of the empty vessel. Ac = πD 2r/4 = (3.142 x 48 2) /4 = 1809.79 cm2 3.1.3 Net Gravitational force The net gravitational force needed in the fluidized vessel bed reactor (dryer that would be exerted on the particles inside the vessel (Saponronnarit, 1999). ∆p = g(ρc - ρg)(1 - ε) h = 9.81(1.3 – 0.00107)(1. 0.84)24 = 4.89N/m2 3.1.4 emf for the reactor The emf for the reactor needed in determining the minimum fluidization velocity for the reactor. This emf is the void fraction at the point of the minimum fluidization. It appears in many of the equations describing the fluid-bed characteristics (Saponronnarit, 1999). is computed thus: Emf = 0.586(Ψ)-0.072 (µ2/ρgηdp3) 0.029 (ρg/ρc ) 0.021 = 0.586(0.7)-0.072 ({1.5x10-4}2/(0.00107x12.7295x0.0053) 0.029 (0.0017/ 1.3) 0.021 = 0.7202 Ψ is the measure of particles not ideal in both shape and roughness (Wei and Yu, 1994). It is calculated by visualizing a sphere whose volume is equal to the particles and dividing the surface area of the sphere by the measured surface area of the particle. 3.1.5 Reynolds number This is a dimensionless parameter that affects the characteristics of the two velocities involved in the study i.e. the minimum and the maximum fluidization velocity. Re = (124dpVp)/ µ = (124 x 0.05 x 6.5458 x10 -5) / (1.5x10-4) = 2.7 Since the Re is less than 10, it gives the type of flow in the fluidizing vessel as a laminar flow and the type of maximum fluidizing velocity needed for the system. 3.1.6 Minimum fluidization velocity (umf). Minimum fluidization velocity: This is the minimum velocity needed to blow the particles of the bed. It is the velocity required to begin the fluidization at which the weight of particles gravitational force equals the drag on the particles from the rising gas. Umf =[(Ψdp) 2 / (150µ)] η [(emf) 3/(1-emf)], where η = g(ρc- ρg) = 12.7295 =[(0.7x 0.05) 2 / (150 x 1.5x10-4)] 12.7295 [(0.47) 3/(1-0.47)] = 0.1357m/s 3.1.7 Maximum fluidization velocity. 27
  • 5. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 The maximum velocity needed for the particles inside the reactor. The maximum fluidization velocity was calculated for the reactor so as to avoid chaotic situation where the particles will not be blown out of the reactor. The drag on the particles will surpass the gravitational force on the particle and the particles will be entrained in the gas. Since the Re number is less than 10, we use the equation, ut = (ηdp2)/[18µ] Thus ut = (ηdp2)/ 18µ = 12.795 x 0.052/(18 x 1.5 x 10-4) = 11.78m/s 3.1.8 The inlet pipe The feed inlet pipe was designed to supply feed at a rate of 1.988m3/min, so as not to create a turbulent situation or flooding of the reactor. The pipe was attached to the reactor at an angle of 30 degrees. The expression used in the calculation of the pipe flow rate into the vessel was based on the work of Eefisso for calculating different flow rates (www.eefisso.com, 2007). This is given as: f r = 1 π Pi 2V = [3.142 x (1.049)2 x 2.3] /4 4 = 1.988m3/s 3.1.9 Mean residence time for the chamber. This is the mean time during with which the molecules remain on the surface of the bed .i.e. the mean time interval between impact and drying (IUPAC Compendium of Chemical Terminology, 1997; Sriparratakul, 1994). τ = v/f = 101.248/1.988 = 50.9799s 3.1.10 Pressure drop in the equipment ∆P, the pressure drop across the bed is closely related to drag force, The pressure drop was calculated based on the work of Jayasuriya and Manrique (2005). ∆Pg = hA∆t = h x 0.00165x (413 - 353) = 0.099h N/m2 3.1.11 Elutriation of Particles from fluidized bed reactor The elutriation process causes a decrease in the particle concentration in the column and the concentration may be empirically modeled by an Arrhenius type expression C = Co e− Mt ; where C = concentration at time t Co = the initial concentration M = empirical constant. 3.1.12 Power Requirement. The power required for setting the designed fluidized bed into operation and the continuation of the operation was based on the suggestions of (Shott et al., 1975). They suggested horse power requirements for different types of flow actions and different reactions. 28
  • 6. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 TABLE 1: Suggested Horse Power Requirements (hp/1000gal). Type of flow Power requirement Types of operations Mild 0.5 – 2 Mixing, blending Medium 2–5 Heat transfer, suspension, gas absorption Violent 5 – 10 Reactions, Emulsification, 3.2 Bill of Quantities The quantities and price of material need for the work are summarized in Table 2. Table 2: Bill of Quantities (a) Construction cost s/n Materials Specifications Quantity Rate (Naira) Cost (Naira) 1 Mild steel G18 1.2×1.2 m 4 4000 16000 2 Mild steel G16 1.2×1.2 m 2 3750 7000 3 Hacco pipe 100×4 m 1 5000 5000 4 Brim plate 4×4 m 1 2000 2000 5 Valves 2 600 1200 6 Electrode 2 1200 2400 7 Electric motor 1 8000 8000 8 Bolts and nuts 20 30 600 9 Electrode 100 10 1000 10 Paints 1 1850 1850 11 Miscellaneous 5000 Total 50,550.00 Adding 10% contingency to the total cost give the total design cost to be 55605 Naira. Adding 25% margin to the total design cost, the machine can be sold at a price of 69509.25 Naira which is still cheaper when compared to other commercial dryers of 126,556. Naira. 3.3 Fabrication of the Fluidize Bed The fabrication of the Fluidize Bed was carried out using the data from the above computations. In addition to that, the following precaution are taken into consideration. a. The fluidization vessel: the vessel was designed to have the capacity of receiving heated fluid (hot air) from the heat source and to house the porous disk. b. The solid inlet feeders: c. Solids discharge d. Dust separator for the exit gas: The dust collector is usually designed to trap any solid, which might want to escape with the exit gas. e. The air supply: the use of an electric motor fan was used to supply air to the system. f. Heat supply: the heat was supplied by a heating element at a temperature of 1150 Celsius. 3.4 Performance Tests Tests were carried out on the designed machine to ascertain its performance. The analysis was carried out on the fluidization reactor to determine the moisture reduction of rice and wheat during the drying process. Before the fluidization process, the weights of the rice and wheat were measured. The grains were fed manually into the equipment and the outputs from the grains outlet were subsequently collected and 29
  • 7. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 weighed. The temperature and pressure were kept constant at the heating chamber throughout the whole process and the time was varied between ten and thirty minutes for different quantities of food samples. The temperature inside the chamber was found to be 63 degrees centigrade. The aim of the experiment was to monitor the reduction of moisture in food grains at different time intervals and constant temperature using rice and wheat as the samples. For the evaluation process the following parameters were employed based on the work of Okoli (1991) and Ojediran and Jekayinfa (2002). Sample evaluations were done using the following as the guide. Moisture content in sample (mc) = original weight (Os) less final weight (Fs). i.e. mc = Os – Fs 12 Drying time for samples (τ) = (.x1 − xr) / N 13 % moisture content (Mc) Loss in weight × 100 Weight of the original sample mc Mc = × 100 14 Os Efficiency of the system (Eff): 1 –Mc = Eff 15 The results of the tests on the designed fluidized bed reactor were taken at 5 minutes interval to ascertain its efficiency; and also were compared with those of some commercial dryers. The results and the graphs are the discussions are presented in section 4. 4.0 Results and Discussion 4.1 Results of Performance Evaluation Table 3: Percentage Moisture Reduction in Grain Samples Time (minutes) Rice (% moisture content reduced) Wheat (% moisture content reduced) 10 4.774 3.212 15 4.896 5.576 20 5.682 7.114 25 7.550 8.605 30 8.048 9.420 35 11.178 9.670 For the results of efficiency of the designed equipment are presented in table 4. 30
  • 8. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 Table 4: Efficiencies of the Fluid Bed Dryer Time (minutes) Rice efficiency Wheat efficiency 10 0.95 0.97 15 0.95 0.94 20 0.94 0.93 25 0.92 0.91 30 0.92 0.91 35 0.89 0.90 Table 5: Performance Test Results Of Commercial Dryers At 20 Minutes Drying air Inlet moisture of Outlet moisture of Moisture reduction in grain temperature (oC) grain (%) grain (%) (%) 115 22.0 20.1 1.9 115 26.0 22.5 3.5 115 28.7 22.5 6.2 115 30.6 23.0 7.6 115 27.0 21.0 6.0 Source: Soponronnarit (1999). R ic e 2 6 W h e a t R ic e W h e a t weight of samples 0 .9 8 0 .9 7 0 .9 6 0 .9 5 2 4 % moisture content 0 .9 4 0 .9 3 0 .9 2 0 .9 1 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 0 .9 0 tim e ( m in u te s ) 0 .8 9 Figure 2: Weight 8of samples 2 1 4 time. 1 0 1 against 1 6 1 8 2 0 2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 tim e ( m in u te s ) An examination of figure 2 shows that as the time in increased the moisture content in particles and their corresponding weights decreases because the moisture content contributed to the total weight of the particles. This shows that the fluidized bed dyer is a good medium for drying of rice and wheat. 31
  • 9. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 R ic e 36 34 32 30 28 drying time (minutes) 26 24 22 20 18 16 14 12 10 8 4 6 8 10 12 m o is t u r e c o n t e n t r e d u c e d F ig u r e 4 . 3 G r a p h o f d r y in g t im e a g a in s t t h e p e r c e n t a g e m o is t u r e c o n t e n t r e d u c e d in r ic e Fig 3: Drying time against Percentage moisture content in rice. W heat 36 34 32 30 28 drying time (minutes) 26 24 22 20 18 16 14 12 10 8 4 6 8 10 12 m o is tu r e c o n te n t r e d u c e d F ig u r e 4 . 4 G r a p h o f d r y i n g t im e a g a in s t t h e p e r c e n t a g e m o is t u r e c o n t e n t r e d u c e d in w h e a t Fig 4: Drying time verses %age moisture in wheat Figures 3 and 4 show the conformity of the fluidized bed dryer to the different drying principles in the literature. As the time is increased so also the moisture reduced until it gets to the equilibrium stage where no moisture will be removed from the grains. Wheat shows a better curve than rice since they are smaller in size and weight than rice. This is probably because the smaller seeds or grains have higher resistance to airflow and therefore reducing the action on fan outputs. 32
  • 10. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 B 8 % moisture reduced 6 4 2 110 115 120 125 130 135 140 145 150 155 temperature degree Figure 4.5 graph of%moisture reduced in commercial fluidized bed dryer against temperature at 20minutes Fig 5: Percentage of moisture Commercial fluidized bed against Temperature (20 min) Figure 5 shows the amount of moisture reduced at different temperatures at the time of 20 minutes. Comparing the efficiencies at the temperature of 115 degrees centigrade and at 20 minutes with the designed fluidized bed dryer, it was seen that the efficiencies is lower when compared with the designed dryer. 5.1 Conclusions In this work the design and fabrication procedure for a low cost fluidized bed has been demonstrated. From the results obtained, it can be inferred that the weights of different samples affect the fluidization process, because grains with higher weights show less resistance to air flow in the system. In addition to that, increasing the airflow speed increases the drying rate but also increases the power consumption in the system, smaller grains show high resistance to airflow therefore reducing the fan outputs and also increasing the amount of moisture reduced in the grains by the hot air giving higher power efficiency in wheat than in rice. A fluidized bed dryer can be competitive with other convectional drying methods especially at high moisture level and low energy consumption. Drying on fluidized bed is a reliable and economical method for drying of light weighted grains. Further work may investigate the energy consumption. Further research should be carried out on other food grains that have different weights and moisture content than the rice and wheat used in this study. References: Baeyens, J. and Geldart, D., Gas Fluidization Technology, Wiley, London, chapter Solids mixing, p 79–86 (1986). Kunii, D., and Levenspiel, O., (1991), Fluidization Engineering 2nd edition. Butterworth-Heinemann Corporation. 33
  • 11. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 Keey, R. B., (1992) Drying of Loose and Particulate Materials, New York: Hemishere Publishers, p 29-32. Aberuagba. F, Odigure. J. O, Adeboye .K. R, and Olutoye. M. A, (2005), Fluidization Characteristics of a Prototype Fluidized Bed Reactor, Leonardo Journal of Sciences. Sripawatakul, O.,(1994), Study of drying Paddy by Cross-Flow Fluidization Technique, Master thesis, Faculty of Engineering, King Mongkutis Institute of Technology, Thonburi, Bangkok, Thailand. Queiroz, C.A.R., Carvalho, R.J, and Moura, F. J. (2005), Oxidation of zinc sulphide concentrate in a fluidized bed reactor-part 1: characterization of the fluid dynamics of the particle bed”, Brazilian journal of chemical engineering, vol 22, number 01, p 117-125 (Jan-March, 2005). Soponronnarit, S. , (1999), Fluidized-Bed paddy Drying, Science Asia Journal 25, p 51-56. Eefisso company, www.eefisso.com, (April, 2007). IUPAC Compendium of Chemical Terminology, (1997). Wen, C.Y., and Yu,Y.H.,(1994), AIChE J., 12, 610. (1994). Jayasuriya. J and Marique. A, (2005), laboratory notes on heat transfer measurement in fluidized bed combustion reactor, Stockholm, (3- Feb-2005). Shott, N.R, Weinstein, B and LaBombard, D., (1975), Motionless Mixers in Plastic Processing, Chem Eng. Prog, Vol 71, No 1. Okoli, J.U. (1991), Some Factors Affecting the Efficiency of Locally Fabricated Palm Kennel/Shell Nut Crackers, NIIE Annual Conference, Ibadan. Ojediran, J.O and Jekayinfa. S.O, (2002), Performance Evaluation of a Centrifugal Palm Nut Cracker, Journal of Applied Science and Technology, Ibadan. NOTATIONS Here we define the notations used in this work. τ = drying time (seconds) X1= initial moisture (kgh20kg-1.d.m) xr = relative moisture (kgh20kg-1.d.m) N = drying velocity (kgh20kg-1.d.m) υ = velocity (ms-1) υ1 = minimal fluidization speed (ms-1) m.d.m = dry matter, mass (kg) β = dimensionless coefficient ρ = density (kg-3) ρ1 = bulk density (kg-3) Wost = water content in fresh material. (Kg/kg) A = heating element area D= Reactor diameter H= Reactor height P= Pressure V= Air velocity ε = porosity 34
  • 12. Innovative Systems Design and Engineering www.iiste.org ISSN 2222-1727 (Paper) ISSN 2222-2871 (Online) Vol 3, No 3, 2012 g = Acceleration due to gravity π = pi ρg = 1.07× 10-3g/cm3 ψ = 0.7 µ = 1.5×10-4 poise h = Bed height Vp = Particle diameter Pi = Pipe Diameter Umf = minimum fluidization velocity Ut = maximum fluidization velocity Mc = % moisture content Mc = moisture content Ac = cross sectional area V = volume Plate 1: Constructed fluidized bed dryer. 35
  • 13. International Journals Call for Paper The IISTE, a U.S. publisher, is currently hosting the academic journals listed below. The peer review process of the following journals usually takes LESS THAN 14 business days and IISTE usually publishes a qualified article within 30 days. Authors should send their full paper to the following email address. More information can be found in the IISTE website : www.iiste.org Business, Economics, Finance and Management PAPER SUBMISSION EMAIL European Journal of Business and Management EJBM@iiste.org Research Journal of Finance and Accounting RJFA@iiste.org Journal of Economics and Sustainable Development JESD@iiste.org Information and Knowledge Management IKM@iiste.org Developing Country Studies DCS@iiste.org Industrial Engineering Letters IEL@iiste.org Physical Sciences, Mathematics and Chemistry PAPER SUBMISSION EMAIL Journal of Natural Sciences Research JNSR@iiste.org Chemistry and Materials Research CMR@iiste.org Mathematical Theory and Modeling MTM@iiste.org Advances in Physics Theories and Applications APTA@iiste.org Chemical and Process Engineering Research CPER@iiste.org Engineering, Technology and Systems PAPER SUBMISSION EMAIL Computer Engineering and Intelligent Systems CEIS@iiste.org Innovative Systems Design and Engineering ISDE@iiste.org Journal of Energy Technologies and Policy JETP@iiste.org Information and Knowledge Management IKM@iiste.org Control Theory and Informatics CTI@iiste.org Journal of Information Engineering and Applications JIEA@iiste.org Industrial Engineering Letters IEL@iiste.org Network and Complex Systems NCS@iiste.org Environment, Civil, Materials Sciences PAPER SUBMISSION EMAIL Journal of Environment and Earth Science JEES@iiste.org Civil and Environmental Research CER@iiste.org Journal of Natural Sciences Research JNSR@iiste.org Civil and Environmental Research CER@iiste.org Life Science, Food and Medical Sciences PAPER SUBMISSION EMAIL Journal of Natural Sciences Research JNSR@iiste.org Journal of Biology, Agriculture and Healthcare JBAH@iiste.org Food Science and Quality Management FSQM@iiste.org Chemistry and Materials Research CMR@iiste.org Education, and other Social Sciences PAPER SUBMISSION EMAIL Journal of Education and Practice JEP@iiste.org Journal of Law, Policy and Globalization JLPG@iiste.org Global knowledge sharing: New Media and Mass Communication NMMC@iiste.org EBSCO, Index Copernicus, Ulrich's Journal of Energy Technologies and Policy JETP@iiste.org Periodicals Directory, JournalTOCS, PKP Historical Research Letter HRL@iiste.org Open Archives Harvester, Bielefeld Academic Search Engine, Elektronische Public Policy and Administration Research PPAR@iiste.org Zeitschriftenbibliothek EZB, Open J-Gate, International Affairs and Global Strategy IAGS@iiste.org OCLC WorldCat, Universe Digtial Library , Research on Humanities and Social Sciences RHSS@iiste.org NewJour, Google Scholar. Developing Country Studies DCS@iiste.org IISTE is member of CrossRef. All journals Arts and Design Studies ADS@iiste.org have high IC Impact Factor Values (ICV).