AT-90-21-2 -- Liquid Pumping Systems for Refrigerant Recirculation PDF

Discusses techniques developed to provide for the required flow of liquid. The earliest of these was the flooded heat exchanger utilising the thermosiphon principle with a liquid supply tank called a surge drum. This led to the development of a number of variations of liquid pumping systems powered by refrigerant gas or system internal pressure, which offered a high degree of reliability in that there were no moving parts, other than the automatic valves, and no seals to leak. There are numerous economic considerations in the selection of the type of pumping system, the size of the pump, and the amount of liquid to be circulated. Brief descriptions of the various types of systems, some application requirements, comparative economics, and a comparison case study for a freezing tunnel are included.

KEYWORDS: refrigeration, refrigerants, recirculating, pumps, circulation pumps, costs, freezers, sizing.