Here are a couple pictures of the AutoCascade we are building. It uses all plate heat-exchangers. System consists of a water-cooled condenser, (no auxiliary condenser), two cascade condensers with their corresponding phase-separators and evaporator. The evaporator will cool circulating methanol from -30C to -60C. A heated water/propylene-glycol loop will reheat the methanol back to -30C. System also includes a suction accumulator and an oil-separator. An expansion tank may or may not be used. I calculate at 25C expected static pressure to be 169-psig. Cycle simulation predicts a duty of 1800W with the evaporator inlet at -73C and saturated vapor outlet at -43C. The compressor is a 12 m3/hr scroll (smallest Copeland 208VAC 3-phase model; 3.5-hp).
Kevin
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