About the authorMike Fisher has over 35 years of experience with refrigeration systems. This background includes; service, installation, equipment manufacturing, research and development, project management, consulting engineering, system design and packaged systems.
In the final entry on this series, the application of hand expansion valves (HEV) to liquid overfeed systems will be discussed. The application of HEV’s in this type of system somewhat differs from those of the prior discussions. When selecting HEV’s for the evaporators where liquid overfeed is being utilized the hand expansion valves take on a secondary function, which may not be obvious at first glance.
In the previous blog entry we discussed the use of hand expansion valves (HEV) maintaining a liquid level in a vessel. In this entry the discussion will center on the HEV being utilized as an expansion device to an evaporator being fed with liquid from a controlled-pressure receiver (CPR).
If you think you may have a problem with draining liquid ammonia from your evaporative condensers, you may want to investigate the equalizing line. This piece of pipe is typically installed on top of the high pressure receiver. The termination of this pipe is usually the discharge line leading to the condensers.
What follows is a brief description of how the equalizing line works.
When your ammonia refrigeration system exhibits a recurring problem issue, how do you solve it? Do you look for the the underlying factors that cause the component to react in the manner it did, or do you replace the component because it did not operate as intended?
