Preheating advantages

Heat/Solvent Recovery. The primary appHcation of heat pipes in the chemical industry is for combustion air preheat on various types of process furnaces which simultaneously increases furnace efficiency and throughput and conserves fuel. Advantages include modular design, isothermal tube temperature eliminating cold corner corrosion, high thermal effectiveness, high reHabiHty and options for removable tubes, alternative materials and arrangements, and replacement or add-on sections for increased performance (see Furnaces, fuel-FIREd). 

The generated water vapor rises through a screen (demister) placed to remove entrained saline water droplets. Rising further, it then condenses on the condenser tube bank, and internal heat recovery is achieved by transferring its heat of condensation to the seawater feed that is thus being preheated. This internal heat recovery is another of the primary advantages of the MSF process. The energy performance of distillation plants is often evaluated by the performance ratio, PR, typically defined as... 

Preheating techniques are commonly employed since these lead to shorter cures, easier flow and generally better products. The high power factor of the material enables high-frequency preheaters to be used successfully. It is also frequently advantageous to pellet the powders as in the case of phenolics. 

Traditional compressor cylinder designs require cooling water jackets to promote uniform distribution of heat created by gas compression and friction. Some of the perceived advantages of water-cooled cylinders are reduced suction gas preheat, better cylinder lubrication, prolonged parts life, and reduced maintenance. 

Compressor Intercooling Whether a compressor should be intercooled or not depends on the trade-off between the increased efficiency of the intercooled compressor and its increased capital cost. In general, intercooling is required for large compressors with pressure ratios that exceed approximately 5 1 (44). The designer also should consider whether the heat is advantageous to the process. For example, when near the 5 1 pressure ratio, it may not be appropriate to intercool if the compressed stream will subsequently require preheating as it would with the process air stream of an MCFC or SOFC system. 

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