Study of energy balance around clinker cooler of cement plant and determing of its efficiency

1. El-Merghib University
Al-khoms
-
Faculty of Engineering
Chemical & Petroleum Engineering Department
Determination of actual efficiency and optimum operation
conditions for clinker cooler in cement plant
Case Study: Lebda Cement Plant
Abdalrzag Emhemmed Alazgal Siraj Ibrahim Alsharif
3115164 3115204
Supervised by:
Dr. Mohamed K. Zambri
Dr. Ali R. Elkais
Fall:2019-2020

2. Outline
 Introduction
 Cement – Manufacturing Process
 Clinker cooler
 Types of clinker cooler
 Clinker cooling
 Clinker cooler efficiency
 Motivations
 Objectives
 Methodology
 References
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3. Introduction
Cement production is considered as one of the
most energy consuming industries.
Cement is produced from raw materials such as
limestone, chalk, shale, clay, and sand. These raw
materials are quarried, crushed, finely ground, and
blended to the correct chemical composition. [1]
Typically, the fine raw material is fed into a large
rotary kiln where it is heated to about 1,400 oC
The high temperature causes the raw materials to
react and form a hard nodular material called
“clinker”
Clinker is cooled and ground with gypsum and
other minor additives to produce cement.
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4. Cement – Manufacturing Process
Raw Material
Preparation
Fuel
Preparation
Clinker
Production
Clinker
Cooling
Finish
Grinding
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Iron Ore
Sand Shall
Clay
Lime stone

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8. Cement Manufacturing process
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Dry Process
To reduce the moisture content of minerals below 1%, which is required for
dry process, the raw materials are dried in a combined drying and grinding
plant.
In this process a Kiln Mixture is a Dry Powder
Advantages
1. preheating done outside the kiln
2. efficiency
3. shorter kiln length
4. the fuel consumption is lowest in the existing technologies.
Disadvantage
1. alkalies, sulfur, chlorides
2. tall, sophisticated

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10. Clinker cooler
Various types of clinker coolers are used
in industry .The grate cooler is one of
them.
It consists of air-permeable grills through
which the cooling
The hot clinker from the kiln, fed directly
on the grill at one end of the cooler,
moves along the cooler length.
Air current passes through the grills and
the clinker bed lying on them.
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11. Types of Clinker Coolers
 Grate Coolers
 Planetary Coolers
 Rotary Coolers
 Shaft Coolers
 Cross-Bar Cooler
 Tube Cooler
Grate coolers are widely
used in cement industries to
recover heat from hot
clinkers coming from the
rotary kiln.
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12. Clinker cooling
 Once the clinker is discharged to the clinker cooler from the kiln, it is cooled
rapidly to minimize glass phase formation and to ensure maximum yield of alite
(tricalcium silicate) formation.[1]
 At the exit of the kiln, the clinker is introduced into the cooler, which injects cold
air from the outside to reduce its temperature from 1,400ºC to 100ºC.
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13. Clinker cooling
 The hot air generated in this device is reintroduced into the furnace to promote
combustion, thus improving the energy efficiency of the process.
 Clinker cooler optimization aims to
 Maximize heat recovery.
 Minimize clinker temperature
 Reduce specific fuel consumption , and
 Improves the quality of cement production.
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Part of air can
be used as
combustion air
The cooling air is blown from
below the grate by fans &
pass through the clinker bed
in cross current

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16. 16
Temperature Profile through the cooler

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18. Clinker cooler efficiency
η =
𝐴 − 𝐵
𝐴
∗ 100%
Efficiency of Cooler Heat losses of clinker cooler
Heat content of clinker leaving the kiln
B consists of
a = Heat loss in cooler exit air
b = Heat loss in clinker leaving cooler
c = Heat loss by radiation

19. The efficiency of
clinker cooler depends
on:
Design and condition
of the internal heat
transfer equipment
Operating condition
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Clinker cooler efficiency

20. Items influence the efficiency
The clinker must be brought in an intensive
contact with the cooling air
The quantity of available cooling air affects
the efficiency
The efficiency is not only determined by the
machine itself, but also by the amount of
cooling air.
The granulometry of the clinker affects the
cooling efficiency
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Lebda Cement Plant (LCP) has a problem in the clinker cooler ,where
the clinker temperature outside the cooler exceeds 100oC and
reaches about 150oC.
Hot clinker has a negative effect on the grinding process.
Also, reduce energy loss to the surrounding environment
In this project , to estimate optimum conditions, of temperature,
pressure, inlet flow rates of clinker and air…….etc. of this cooler
Motivations

22. Objectives
This Project aims to:
 Determining amount of heat loss form the grate cooler
 Determining theoretical (Design) efficiency for clinker cooler in
Lebda cement plant
 Determining actual efficiency for clinker cooler in Lebda cement
plant
 Compare results and determine the optimum operating
conditions for clinker cooler.
 Suggest solutions to improve the clinker cooler efficiency
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23. To accomplish the project objectives, the
following points are considered:
 Collect data and samples from the cooler.
 Material balance calculations.
 Energy balance calculations.
 Determine the theoretical efficiency.
 Determine the operating efficiency.
 Analyze the results and estimate the optimum operating
conditions.
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Methodology

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INPUT
• Hot clinker
• Cooling air
OUTPUT
• Cooled clinker
• Exhaust air
• Secondary air
• Tertiary air

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Grate Cooler Measurement
Clinker Input (TPH)
Air Cooler Rate
Exhaust Air rate
Tin Grate cooler
Tout grate cooler
Texhaust air
Tsecondary air
Tambient
Methodology
the measurements and subsequent calculation based on the principle of
input and output of clinker from the grate cooler.

26. References
1. International Finance Corporation, “Improving Thermal and Electric Energy
Efficiency at Cement Plants”, 2017.
2. G
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7. G
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27. Lebda Cement Plant
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