A successful journey of CB Cooler showcasing Commendable Results
A successful journey of CB Cooler showcasing Commendable Results

A successful journey of CB Cooler showcasing Commendable Results

Over the years from Planetary coolers till date, FLSmidth, the pioneers in inventing new technologies for enhancing the energy efficiency of cement plant operations, came out with SF coolers in the year 1997. The SF cooler was launched aiming at the necessity of having consistency in fuel consumption having separate conveying and cooling mechanisms. Installations close to 250 in numbers in a span of 14 years ranging from 540 tpd to 13,000 tpd clinker production speaks for itself about the success.

In the arena of changes, we come across raw material change, fuel change, market demands for different quality clinkers, alternate fuel usage, etc. In all such conditions, the cooler being the final architect giving shape to the quality clinker, should be capable enough to address and take care of our day-to-day material and operational changes.

In the year 2011, FLSmidth launched FLSmidth® Cross-Bar® Cooler to take care of the day-to-day changes with the inbuilt idea of overcoming all our day-to-day operational problems of snow man, red river, in consistent clinker PSD and much more. In a shot span of less than 5 years, more than 70 installations ranging from 1,100 tpd to 12,500 tpd clinker production is yet another benchmark for its success. Consistency in Specific Fuel Consumption for clinker production in the complete pyro system is more inevitable. By having the separate conveying and cooling mechanism with MFRs, FLSmidth® Cross-Bar® Coolers were showcasing the consistency in fuel consumption for more than 18 years and on. A 1% loss in cooler efficiency will impact 5 kcal/kg clinker in terms of fuel consumption. This in turn has the direct impact on the pre-heater fan power consumption, coal mill run hours and coal handling & conveying system. Savings from the constantly higher recuperation from the cross-bar coolers outweigh the marginal savings in specific power consumption of the older generation beam technology coolers.

UltraTech Cement Limited, Awarpur Cement Works is one of the oldest plants of Indian cement industry located in Maharashtra. It has two lines in operation with a combined operating capacity of 3.3 MTPA of clinker production. Line 1 Pyro system was operating with 4 stage SLC tower and CFG grate cooler operating at 4,000 tpd clinker production.

UltraTech went in for FLSmidth as a one source partner to upgrade its Line 1 Pyro system in two phases. FLSmidth as a one source partner is responsible for the complete civil engineering, mechanical engineering, E&I engineering and the hooking up of newly installed equipment with the existing PLC for the complete upgrade project.

In the first phase the existing grate cooler was replaced with the new CB cooler. FLSmidth as a One Source Partner to UltraTech in this upgrade completed the cooler replacement with UltraTech Support and lighted up the plant on 3rd November, 2014. The performance guarantee for the cooler replacement was carried out on 17 October 2015. Sufficient time was given to demonstrate the consistency in cooler performance and cooler losses and the PG trial was taken almost after a year.

Table 1 portrays the values recorded during base line test and during the performance guarantee trial.

Cooler Losses at 1.15 kg/kg clinker recuperation air and 36°C Ambient. Refer Table 2 UltraTech Cement had the WHR system incorporated in the cooler and in the preheater system. The Table 3 portrays the before and after conditions of the hot air taken for power generation in the prevailing WHR system.

In CB coolers, the quality of heat is maintained in such a way that the recuperation and the WHR system get the maximum heat available from the red hot clinker. The reason being in case of CB cooler we pump less quantity of air when compared to the older generation beam technology coolers from underneath the compartment efficiently by means of MFRs. This in turn maintains the air flow as per requirement to the upper clinker bed and ensures uniform cooling and better heat removal from the hot clinker. As we do not dilute the heat available in the hot clinker by pumping more air, the above parameters are achieved without recirculation of hot air from cooler vent and thereby we need not compromise on the clinker temperature as well.

By Logesh Baskaran, Senior Manager - Products and Upgrades Sales, Cement Project Division.

Table 1: CB Cooler Performance Before and After Modification

Parameters

Before Cooler
Replacement-Base line
Guarantee After Cooler
Replacement
Clinker Capacity (TPD) 3,933 Same as Baseline 4,073
Cooler Loss (kcal/kg Clinker) - Cooler Vent & Clinker losses 151 99.5 90.5
Cooler Specific POwer Consumption (kWh/t) - Equipment Include
Cooler Drives, Cooler Compartment Fans (w/o Silencer) & HRB
5.7 5.1 4.9
Clinker Temperature (°C) 115 65 + ambient 48 + ambient

Table 2: Cooler Balance Before & After CB Cooler

Parameter

Before Modification- Base line Measurement Data After CB Cooler Installation
INPUT kg air/kg Clinker

Temp (° C)

kcal/kg clinker kg air/kg Clinker Temp (°C)

Kcal/kg clinker

Clinker 1.0 1450 383 1.0 1450 383
Clinker Dust 0.05 1450 19.2 0.05 1450 19.2
Cooling Air Input 2.6 30 18.8 2.27 36 19.7
Cooler Fan Power 4.7
4.0 4.1 36 3.5
TOTAL INPUT 425 425
OUTPUT kg air/kg Clinker Temp (° C) kcal/kg clinker kg air/kg Clinker Temp (° C) kcal/kg clinker
Tertiary Air 0.78 811 165.1 0.72 938 178.9
Tertiary Air Dust 0.03 811 6.2 0.03 938 5.5
Secondary Air 0.42 840 92.4 0.43 1179 136.9
Secondary Dust 0.02 840 3.5 0.03 1179 7.2
Vent Air 1.42 292 105.6 1.12 270 75.0
Clinker 1.0 115 21.7 1.0 84 15.5
Lat. heat of
evaporation of water


23.5

0
Radiation

8

6
TOTAL OUTPUT 425 425

Table 3: Mid Air to WHR Before & After CB Cooler.

Parameters

Before CB Cooler After CB Cooler
Mid Air Temperature (°C) 375 (Avg) 400 (Avg)
Steam Generation (TPH) 5.3 5.8

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