A Process and Pilot Plant Design Study of the Absorption Freezing Vapor Compression Process.

摘要

A design study of the Absorption Freezing Vapor Compression (AFVC) process for desalination and other concentration/separation treatments of waste water was conducted. The AFVC process overcomes one of the major problem areas in previous freezing processes by using a closed cycle refrigerant loop to power the absorption cycle,thus eliminating compressor problems caused by direct compression of refrigerants contaminated with sea water. The process maintains low energy requirements with absorption cycle powered by a heat pump. Power consumptions of 42and 38kw-hr/1000gal were calculated for 100,000and 1million gpd plants respectively. A 25,000 gpf pilot plant was designed which consists of three major process vessels:freezer/absorber;wash column/melter and generator;and equipment skids,one for refrigeration equipment and one for pumps,air removal equipment,and heat exchangers. Capital and operating costs were calculated for 100,000gpd and 1million gpd plants as well as for the pilot plant. The major advantages of the AFVC process are summarized: (1) low power consumption of freezing compared to heat processes,which is especially important in view of rising fuel costs; (2) less corrosion using epoxy coated mild steel and aluminum which are not completely suitable for evaporative process plants and are often replaced by more costly titanium in heat processes; (3) no pretreatment is needed to prevent scaling even with brackish water saturated with calcium sulfate.