2. Dust collectors
and cross
contamination

3.  A dust collector is a system used to enhance
the quality of air released from industrial
and commercial processes by
collecting dust and other impurities from air
or gas.

4.  Designed to handle high-volume dust loads, a
dust collector system consists of a blower,
dust filter, a filter-cleaning system, and a
dust receptacle or dust removal system.

5.  Dust collectors may be of single unit
construction, or a collection of devices used
to separate particulate matter from the
process air.
 They are often used as an air pollution
control device to maintain or improve air
quality.

6.  Dust collectors are used in many processes to
either recover valuable granular solid or
powder from process streams, or to remove
granular solid pollutants from exhaust gases
prior to venting to the atmosphere.
 They are often used as an air pollution
control device to maintain or improve air
quality.

7.  Identification and removal of dust have had a
profound effect on plant layout as well as on
the design and construction of production
area.

8.  Although many types of dust collectors are
available.
 The selection of equipment should be based
primarily on its intended application.

9.  Cyclone collectors
 Wet collectors
 Wet scrubber
 Rotoclone
 Replaceable filter
 Cloth bag
 HEPA

10.  Cyclone dust collector is an efficient dust
removing equipment.
 It greatly helps in reducing the dust inside
the workshop and in the exhaust.

12.  Cyclones use centrifugal force to separate
particulate out of the airstream.
 There are no moving parts inside a cyclone
body and no filter media.

13.  Air and particulate enter the inlet at a high
velocity along the inner wall at the top of
the cylindrical cyclone body.
 This starts a spinning path as inertia forces
the particulate against the inner wall,
resulting in a relatively clean area in the
center.

14.  This clean air is exhausted through an outlet
chamber that starts in the center of the
cyclone and exits out the top.
 As gravity starts pulling the spinning
particulate down.

15.  The taper of the cyclone body helps keep
the spinning (cyclonic) effect in motion until
it drops out the bottom of the cyclone body
and into a hopper.

16. Wet scrubber
Rotoclone

17.  Wet Scrubbers are effective air pollution
control devices for removing particles and/or
gases from industrial exhaust streams.
 In these systems, the scrubbing liquid
(usually water) comes into contact with a gas
stream containing dust particles.

18.  Greater contact of the gas and liquid streams
yields higher dust removal efficiency.

20.  Wet scrubbers operate by introducing the
dirty gas stream with a scrubbing liquid –
typically water.
 Particulate or gases are collected in the
scrubbing liquid.

21.  Wet Scrubbers are common in many
industrial applications including pollutant
reduction at petroleum refineries, chemical
processes, acid manufacturing plants, and
steel making.

22.  Rotoclone collector cleans the air by the
combined action of centrifugal force and a
violent inter-mixing of water and dust laden
air.
 The dust is separated from the gas stream by
means of a water and by the high velocity
flow of air past a stationary impeller.

23.  This high velocity flow carries water with it
in a heavy turbulent sheet.
 The centrifugal force exerted by the rapid
changes in direction of airflow causes the
dust particles to penetrate the water
droplets and become permanently trapped
within them.

24.  The dust-laden water droplets are then
removed from the air stream by the water
eliminator.
 The dust settles in the bottom of the
collector and the water is reused.

25.  Since the water curtain is produced by the
airflow, no pumps or nozzles are required.

26.  This type of scrubber is efficient and uses a
minimal amount of water.
 Both systems are particularly effective when
a dye is used as the component of a dosage
form.

27.  Most commonly used dust collectors are
 Replaceable filter
 Cloth bag
 HEPA

28.  In large operation, the dust collectors are
placed on roof.

29.  High-efficiency particulate air or HEPA is a
type of air filter
 Filters meeting the HEPA standard have
many applications, including use in medical
facilities, automobiles, aircraft and homes.

31.  A HEPA filter is used in an air purifier to help
filter harmful pollutants and allergens out of
the air.
 This technology was developed by the U.S.
Atomic Energy Commission to remove the
airborne radioactive particles from the air

32.  it has to be able to remove 99.7% of the
particles as small as 0.3 microns from the air.
 It works by circulating the air to purify it.

33.  The dust-laden air enters the bag filter
bustle.
 The air is uniformly distributed avoiding
channeling.
 Initially a coat of material forms on the bags.
 Subsequently, the coat acts as the filtering
medium.
 The dust is accumulated on filter elements
while the air passes thorough the filter bags
from outside to inside.

34. 

35.  The accumulated powder is dislodged from
the bags by reverse pulse-jet air
intermittently.
 The dislodged powder falls on bottom cone
and is discharged through powder discharge
valves.
 The dust free air is sucked by induced draft
fan and is exhausted to atmosphere.

36.  Inaddition to selecting the correct type of dust
collector for each department.
 It is desirable to provide the
 Air volume
 velocity
 Required for the collector to do its job effectively.

37. SPECIFICATIONS
Bag
Motor
Powder cord
Air flow
Dimension
Weight
30 gallon capacity
½ industrial-duty
capacitors starts
12 long
330 cfm
21 width×26 long×48 high
approximately 64 pounds
The dust collectors specifications will gives you
a idea of its capabilities .

38.  The major departments which includes
specifications are :
1. Chemical weighing
2. Tablet granulating
3. Compressing
4. Coating
5. Tablet packaging

39. Chemical weighing
 In such cases HEPA
filtration should be
used.
 The hood for each 14x15
foot booth have a
capacity of 4500 cfm
with a face velocity in
excess of 150 feet per
mint

40.  Since granulating operations used
several different picec of
equipment ,each with its on
unique problm,dust collection can
best be described in general
terms.
 If the area is air condition ,it is
possible to minimize cost by
reusing 85%of the air,provided an
HEPA b filter is used.

41.  Flexible 3 or 4 inche house should have an air
capacity of 200 to 300 cfm and a linear
velocity of more than 2500 feet per mint for
best result.

42.  When apply to tablet pressing ,however ,at
least 450 cfm and velocity of over 3000 feet
per mint are needed

43.  Atypically 42 inch coating pan
should have supply inlet of 200
cfm and an exhaust of 300 cfm
when standard ducts are used.
 Absoulte filters are preferable
if 85% of air is to be
recirculated.

44.  If solvent film coating is performed in
conventional Accela cota or Pellegrino pan
,not only does air volume have to be
increased substantially, but the discharged
air must be treated to conform to local and
government environment standards.
 Rlexible hoses used at tablet counters.
 Powder fillers and cottoning machine should
handle about 200 to 300 cfm at a minimal
velocity of 2000 feet per mint.