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CLINKER COOLER
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
CONTENT • Principle of cooler
• Types / Generation of cooler • Working principle • Optimizing the cooler operation • Instrumentation and Control
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
2
PRINCIPLE OF COOLER
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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WHY DO WE NEED A CLINKER COOLER..?? 1. To recuperate heat from clinker. 2. Hot clinker - difficult to convey 3. Hot clinker shows negative effect on grinding process 4. Proper Cooling improves the quality of Cement
WHY DO WE NEED A CLINKER BREAKER AT THE COOLER DISCHARGE..?? To crush the clinker to the acceptable feed size for cement mill (Ball Mill / VRM).
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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MODES OF HEAT TRANSFER INVOLVED IN CLINKER COOLING
Conduction
Convection
Radiation
Heat moves to clinker edge by conduction
Heat transfer by radiation and convection
Air flows over clinker cooling surface
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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TYPES OF FLOW Air
Air
Air
Material
Material
Material
Parallel flow
Counterflow
Cross-flow
material material
material
T
T
T
air
air
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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TYPES OF COOLER
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COOLER TYPES
Planetary cooler
Rotary cooler
Grate cooler
1st Generation Grate Coolers – conventional grate
2nd Generation Grate Coolers – air-beam grate
3rd Generation Grate Coolers – stationary grate
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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PLANETARY COOLER
ADVANTAGES
DISADVANTAGES
Operates without Excess Air
High Clinker Temperature > 150 °C
Simplicity – Low Investment
No TAD Capability
Common Drive (Only 1.5kwh/MT)
Limited Capacity – No Calciner The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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ROTARY COOLER
ADVANTAGES
DISADVANTAGES
Operates without Excess Air
High Clinker Temperature > 225 ° C
Permits TAD Take-off
Separate Drive ~ 3.5 kWh/MT
Low Radiation Losses
Higher Investment and maintenance Cost The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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1ST GENERATION CONVENTIONAL GRATE COOLERS Advantages of Conventional Grate Cooler Ability to handle large capacities Capable of achieving low clinker temperature Favourable heat recuperation
Permits take out of hot tertiary air
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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2nd GENERATION AIR BEAM TECHNOLOGY COOLER
IKN – Pendulum Cooler FLSmidth – COOLAX – CFG Cooler
Advantages of Air beam technology Cooler Ability to handle large capacities Better recuperation compared to conventional grate cooler Improved Cooling air distribution The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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3rd GENERATION – STATIONARY GRATE COOLER FLSmidth – CB Cooler
Polysuis - POLYTRACK
KHD - Pyrofloor
Advantages of Stationary Cooler No fall Through Low Wear Parts Low Cooler Loss Low Maintenance and Power High Efficiency The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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WORKING PRINCIPLE OF COOLER
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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Grate Plate Polysuis - POLYTRACK FLSmidth – CB Cooler KHD Cooler - PYROFLOOR
IKN Pendulum Cooler
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FLOW REGULATOR
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FLOW REGULATOR AND CENVENTIONAL TECHNOLOGY
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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OPERATION OF FLOW REGULATOR
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VELOCITY PROFILE COMPARISION
PASSIVE
ACTIVE – Flow Regulator The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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Flow regulator PRESSURE DROP
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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FLSMIDTH CROSS BAR COOLER Advantages of CB Cooler Horizontal Clinker transport Improved Transportation efficiency Highly flexible for new construction and upgrades
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MEASUREMENTS & OPTIMISING THE COOLER OPERATION
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OPTIMISING THE COOLER
TO ensure the cooler is operated efficiently, the following needs to be monitored Cooler Heat Balance. Cooler Efficiency. Cooler Losses.
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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COOLER MASS AND HEAT BALANCE
Cooler Inputs Clinker Input
Cooling Air Input Fan Energy Input Water Injection
Cooler Outputs Secondary and Tertiary Air Calculation Excess Air Clinker Temperature Cooler Radiation
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Measurements taken in cooler for cooler heat balance 1. 2. 3. 4.
Cooler air fan flow Cooler excess air fan flow – temperature Tertiary air flow – temperature Clinker temperature. TAD - 3 Cooler excess air - 2 Kiln
4
Cooler
Cooler fans - 1 The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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Cooler air fan flow measurement
V – Velocity – From Anemometer readings (m/s) A – Cross Section area of fan inlet area (m2) ρ - Density of air (kg/m3) ρN –Density of air at Normal Conditions – 1.293 kg/m3 t – Temperature of ambient air Ps – Static Pressure at fan inlet
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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COOLER INPUT Clinker Input The amount of clinker is found by physical measurement of clinker coming out of the cooler including all dust. Clinker Input is considered as 1 kg which is taken as the basis for the Mass & Heat balance. Total Clinker from Drop Test
= 200 TPH
Clinker Input
= 200/200
= 1 kg/kg Clinker
Cooling Air Input Velocities of each fan to be measured at fan inlet using the anemometer. The flow can be found from the formula, Volumetric Flow Rate, Q [m3/Sec]
= Velocity [m/Sec] x Fan Inlet Area [m2]
Mass Flow Rate [kg/hr]
= Q [m3/Sec] x Density x [kg/m3] x3600
Specific Mass Flow
= Q [kg/hr] / Total Clinker [kg/hr] = 4,20,000/(200*1000)
Fan Energy Input
= 2.1 kg/kg Clinker
Power Consumed by all Cooler Fans
= 1198 kw
** The value is at meter , 1 % Line Loss and 5 %
Fan Energy
= 1198/200
Motor Loss is to be subtracted and convert it to heat
= 5.99** kwh/t
(kCal/kg Clinker) by using with 0.86
Water Injection
Specific Water Flow [kg/kg Clinker] = Net Water Flow [kg/hr] / Total Clinker [kg/hr] The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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COOLER OUTPUT SECONDARY AND TERTIARY AIR CALCULATION Typical stoichiometric combustion air amount: LMIN = ~1.42kg air/1000kcal (low heat value) Actual combustion air amount:
LCOMBUSTION = LMIN * λ Where: 1
Lambda: λ 1
79.1 O2 x 20.9 100 CO2 O2
LCOOLER = LCOMBUSTION - LP+T - ΣLFALSE The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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Cooler Excess Air Fan – Flow measurement
f – Pitot Tube Constant (0.8-0.85) Pd – Dynamic Pressure (Pa) – from Pitot Tube Measurement g – Acceleration of gravity (m/s2) A – Cross Section of duct (m2)
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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COOLER OUTPUT EXCESS AIR The cooler Excess air can be found by measuring the temperature and static pressure at cooler ESP inlet or ESP fan inlet or at Cooler ESP Stack. From Stack Cooler Excess air will be found by back calculation as follows. 1. Gas inlet condition 2. Leak air inlet condition 3. Gas outlet condition
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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COOLER OUTPUT
Clinker Temperature Clinker temperature is to be measured by taking clinker samples in an insulated closed container. Clinker considered for measurement must be sieved in – 12 mm and + 6 mm sieves. Coating pieces and red hot pieces must be removed. It is recommended to take the samples before Clinker crusher. This is mainly because coating pieces will be crushed in clinker crusher zone and this must be avoided.
Cooler Radiation Cooler radiation is calculated from the surface temperature and surface area. In general cooler radiation for modern cooler will be around 6 kcal/kg Clinker.
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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Specific heat calculation (Cp)
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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Summary of measurements Cooler input air – Mass – Temperature Cooler excess air – Mass – Temperature Tertiary Air – Temperature Clinker temperature at cooler outlet Fan Energy
Summary of calculation
Secondary and tertiary air – Mass / Flow Radiation loss Specific heat of all parameter with reference to the measured temperature The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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Typical Cooler Mass and Heat Balance Input
Flow kg/kg
Temp °C
Cp Kcal/kg/°C
Ref = 0
Ref amb.
Clinker
1.000
1450
0.264
383.0
381.3
Dust
0.050
1450
0.264
19.2
19.1
Cooling Air
1.928
10
0.237
4.6
0.0
5.2
5.2
0.0
0.0
411.9
405.4
Fan Energy in kWh/t Water Injection
5.99 0.000
15
1
Total Heat, In Flow kg/kg
Temp °C
Cp Kcal/kg/°C
Ref = 0
Ref amb.
Secondary Air
0.312
1119
0.262
91.5
90.7
Secondary Air Dust
0.020
1119
0.245
5.5
5.4
Tertiary Air
0.703
1020
0.262
187.9
186.2
Tertiary Air Dust
0.030
1020
0.244
7.5
7.4
Excess Air
0.914
375
0.238
81.6
79.4
Excess Air Dust
0.000
375
0.195
0.0
0.0
Clinker
1.000
165
0.194
32.1
30.3
6.0
6.0
0.0
0.0
411.9
405.4
Output
Radiation Heating + Evaporation of Water Total Heat, Out
0.00
579
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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AIR LOAD CALCULATIONS Cooler Air Load is the ratio of the amount of air supplied to the cooler loading area.
COOLER SPECIFIC AIR Cooler Specific Air is the ratio of the amount of air supplied to the clinker production.
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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EXAMPLE FOR AIR LOAD AND SPECIFIC AIR
Air flow
Specific Air
Area
Air Load
Fans m3/min
Kg/min
Kg/Kg Clk
m2
kg/min/m2
FN01-K11
1332.24
1555.74
0.28
13.65
113.97
FN02-K21
923.04
1077.89
0.19
10.92
98.71
FN03-K22
1374.77
1605.40
0.29
16.38
98.01
FN04-K31
860.55
1004.91
0.18
10.92
92.02
FN05-K32
1282.78
1497.98
0.27
16.38
91.45
FN06-K41
1457.404
1700.79
0.304
27.30
62.30
FN07-K51
1393.08
1626.78
0.29
27.30
59.59
FN08-K61
1305.31
1524.29
0.273
27.30
55.83
Total
9929.174
11594
2.077
150.15
Here is an example of air load calculation for a complete cooler. Kiln Feed = 550 TPH Kiln Production=8049 TPD Density= 1.167 kg/m3
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11 April 2014
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COOLER LOADING The cooler loading is defined as the amount of clinker over the grate area.
Cooler Loading for the above example is calculated as
Cooler Type
Maximum Loading (TPD/m2)
Cooling Air (kg/kg Clk)
Rotary Cooler
38
3.3
Grate Cooler
50
2.55
Cross Bar Cooler
46
2.3
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11 April 2014
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COOLER EFFICIENCY
Better Clinker quality
Higher cooler efficiency - Lower specific fuel consumption
Lower clinker temperature - Handling clinker shall be much more easier
Other Indirect benefits …
Reduction in PH fan power consumption
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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COOLER EFFICIENCY The efficiency of a cooler is defined as the relationship between the recuperated heat to the kiln and the total heat transferred to the cooler.
Where, Cooler Loss
= (TKO x SKTKO) + (MEX x TEX x SATEX) + RA
TKO
= Temperature of clinker leaving the cooler
SKTKO
= Specific Heat of Clinker leaving the cooler
MEX
= kg of excess air per kg of clinker
TEX
= Temperature of excess air
SATEX
= Specific heat of excess air
MCA
= kg of cooling air per kg of clinker
TCA
= Temperature of cooling air
SATCA
= Specific heat of cooling air
RA
= Cooler housing radiation in kcal/kg of clinker The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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What is Cooler efficiency???
Cooler efficiency =
=
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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Heat Available / Heat Input •
Heat content of clinker from kiln (Clinker–1450°C)
• Heat content of cooler air (ambient air)
Cooler
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11 April 2014
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Heat loss
Heat content of cooler vent gas Radiation Heat content of clinker at exit
Radiation
Cooler
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Tertiary Air Cooler / Heat loss
Heat Recuperated
Radiation Secondary Air
Cooler
Heat Input
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11 April 2014
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Basis of Cooler loss
Actual Cooler loss
VDZ Cooler loss
Standard Cooler loss
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11 April 2014
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Actual Cooler loss (ref 0°C)
Actual Cooler loss = Heat Content of clinker at 0°C + Heat Content of excess air at 0°C + Radiation loss
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VDZ Cooler loss (ref ambient air °C) Verein Deutscher Zementwerke – German Cement Works Association
VDZ Cooler loss = Heat Content of clinker w.r.t amb°C + Heat Content of excess air w.r.t amb°C + Radiation loss
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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Standard Cooler loss (ref ambient air °C)
Standard Cooler loss basis •Combustion air – 1.15 kg/kg clk
Standard Cooler loss (kcal/kg clinker) = Heat Content of clinker w.r.t amb°C + Heat Content of excess air w.r.t amb°C + Radiation loss
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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OVERALL COMPARISON
Total Cooler Loss
VDZ Cooler Loss (Net Cooler Loss Ref Cooling Air Temperature)
Standard Cooler loss (Normalize) Standard Cooler loss (kcal/kg clinker) = Heat Content of clinker w.r.t amb°C + Heat Content of excess air w.r.t amb°C + Radiation loss The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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ACTUAL LOSS Vs STANDARD LOSS
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Summary of cooler performance
Cooler loss – From heat balance Cooler efficiency – From formula Clinker temperature – From measurement Cooler parameters
Bench Mark Values
Standard Cooler loss (kcal/kg clinker)
≤ 95
Cooler efficiency (%)
≥ 75%
Clinker temperature (°C)
Your cooler
≤ 65+ambient
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11 April 2014
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Possible reasons for cooler inefficiency
Grate plates worn out (Applicable for 2nd generation cooler) Insufficient cooler air Clinker bed – not optimum Too high cooler width / grate load Clinker PSD – Too fine clinker – This shall lead to red river, if not cooled initially. Clinker chemistry
The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
11 April 2014
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Typical Comparison Table of all Cooler Loss Planetary Cooler
Conventional Grate Cooler
Radiation
97
Excess Air
0
Clinker (150 deg C) Total Loss
Radiation Excess Air (1.85 kg/kg @ 240 deg C)
25
Clinker (90 deg C)
122 kcal/kg
Total Loss
Rotary Cooler 75
Excess Air
0
Total Loss
108 17 131 kcal/kg
Air Beam Grate Cooler
Radiation
Clinker (225 deg C)
6
Radiation
45 120 kcal/kg
6
Excess Air (1.2 kg/kg @ 240 deg C)
70
Clinker (90 deg C)
17
Total Loss
93 kcal/kg
Cross Bar Cooler Radiation
6
Excess Air (1.0 kg/kg @ 240 deg C)
58
Clinker (90 deg C)
17
Total Loss
81 kcal/kg The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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COOLER LOSS – A TYPICAL COMPARISION STUDY Parameters
Conventional Cooler
Air Beam Cooler
Cross Bar Cooler
Mass
Temp
Heat
Mass
Temp
Heat
Mass
Temp
Heat
Kiln Exit
1
1450
383
1
1450
383
1
1450
383
Cooling Air
3.10
35
26
2.55
35
21
2.15
35
18
Sec Air
0.45
1070
126
0.45
1220
145
0.45
1260
150
Tertiary Air
0.65
750
124
0.65
815
135
0.65
870
145
Excess Air
2.0
265
130
1.45
270
95
1.05
295
75
Clinker
1
100
19
1
100
19
1
100
19
Radiation
-
-
11
-
-
11
-
-
11
Total Loss
-
-
160
-
-
125
-
-
105
STD Loss
-
-
130
-
-
100
-
-
85
Note : Mass in kg/kg Clinker , Temp in deg C & Heat in kcal/kg
All the three coolers has the same combustion air but the cooler loss reduced by 55 kcal/kg in Cross Bar cooler when compared to conventional cooler. The excess air which is the major loss in cooler is reduced to 1 kg/kg Clinker and where as heat
reduced to heat 75 kcal/kg. The Cooling air input is reduced from 3.10 to 2.15 kg/kg Clinker. The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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EXAMPLE For clear understanding this can be discussed with an example. Let's consider, P = 200 TPH, NCV = 5500 kcal/kg, then saving in fuel is,
Note:It
must
be
noted
we
have
projected only the heat savings.
Specific Heat Saving
Heat Saving
Fuel Saved
= Conventional Cooler Loss – SF Cooler Loss
We will have additional savings in
= 160 – 105
electrical consumption because of
= 55 kcal/kg
following reasons.
= 55 x 200 x 1000
Reduction
= 11 x 106 kcal/hr
reduces
the
required
for
= 11 x 106/5500
input
cooling
number fans
of
required
air fans for
system.
= 2000 kg/hr = 2 tons/hr i.e., 48 tons/day
Subsequent reduction in excess air quantity will gave some benefits in
Assume Cost of 1 ton coal = 53 €
Amount Saved per day
in
terms of power savings in cooler
= 53 € x 48
vent fan.
= 2,533 € /day Amount Saved per annum (330 Days) = 76320 € /annum The information contained or referenced in this presentation is confidential and proprietary to FLSmidth and is protected by copyright or trade secret laws.
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1st Generation Cooler
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11 April 2014
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2nd Generation Cooler
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11 April 2014
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3rd Generation Cooler
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11 April 2014
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