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FARAN Co.
Process And Energy Engineering Company
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Waste Heat Recovery System
Large quantity of hot flue gases is generated from Boilers, Kilns, Ovens and Furnaces. If some of this waste heat could be recovered, a considerable amount of primary fuel could be saved. The essential quality of heat is not the amount but rather its “value”. The strategy of how to recover this heat depends in part on the temperature of the waste heat gases and the economics involved. Depending upon the type of process, waste heat can be rejected at virtually any temperature from that of chilled cooling water to high temperature waste gases from an industrial furnace or kiln. Usually higher the temperature, higher the quality and more cost effective is the heat recovery. Benefits of ‘waste heat recovery’ can be broadly classified in two categories: Recovery of waste heat has a direct effect on the efficiency of the process. This is reflected by reduction in the utility consumption & costs, and process cost and Reduction in pollution, equipment sizes, and auxiliary energy consumption are indirect benefits of waste heat recovery system. Faran Process & Engineering Co. with foreign co-operator companies is able to conduct wide range of services in waste heat recovery field such as Consulting, Engineering, procurement, and Construction. Waste Heat Recovery in Cement Factories
Waste heat recovery is the common method used for decreasing the specific energy consumption in cement factories. Discharged hot gases from preheater and cooler are the main source of waste heat in cement factories. Waste heat recovery is applicable for new technologies (short kiln & five stages preheater) and old technologies (long kiln). Purified Water heated, steamed and superheated by means of heat that is recovered from the waste heat sources. Steam turbine is also applied for electrical energy production. Energy Price and Heat Quality are the main factors that influence the feasibility study of waste heat recovery projects. The temperature of discharged gas from preheater is between 370˚C to 450˚C and discharged gas from cooler is between 370˚C to 450˚C which is rather suitable for heat recovery. The following table shows the Electrical energy production capabilities from waste heat recovery in the cement factories.
Produced electrical energy is contributed to supply a quota of whole energy consumption in the cement factories. WHRS can supply 20 to 38 kWh per ton of clinker in cement factories. The amount of energy production in WHRS depends on utilization of raw mill. Purified treated water and feed of boilers, are supplied by water treatment plant. Water transfer pumps are applied for water transportation into the boilers. Superheated steam, generated by boilers, feed in to the steam turbine for electrical energy generation. The flow rate of water remains constant by makeup line.
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