US 5,181,391 A · Refrigerant handling system with air purge and multiple refrigerant capabilities

Abstract

A refrigerant handling system that includes a liquid refrigerant storage container and a pump for feeding refrigerant in liquid phase to the container so that any air in the container or carried by the circulating refrigerant is captured within the container over the refrigerant. A bulb containing a reference refrigerant (R12) is positioned in heat transfer relation with refrigerant fed to the container. A pressure gauge is coupled to the bulb and calibrated to indicate saturation temperature of the reference refrigerant, and thereby reflect actual temperature of refrigerant in the container. A differential pressure gauge has separate scales for multiple refrigerant types (R22, R134a, R500, R502) to indicate apparent refrigerant temperature as a function of any bulb/container pressure differential. A valve is coupled to the container for venting air therefrom when apparent refrigerant temperature exceeds actual refrigerant temperature for the specific refrigerant type under service.

Claims15

Dependent claims

In a refrigerant handling system that includes a first volume and means for feeding refrigerant in liquid phase to said first volume so as to capture air in said volume over the refrigerant, the refrigerant being characterized by a saturation pressure that varies with refrigerant type and temperature, means for purging air captured within said first volume comprising:

first means operatively coupled to said first volume for providing an indication of actual temperature of refrigerant in said first volume,
second means operatively coupled to said first volume and responsive to refrigerant/air vapor pressure within said first volume for providing an indication of an apparent temperature of refrigerant within said first volume as a function of said refrigerant/air vapor pressure and saturation pressure/temperature characteristics of the specific type of refrigerant within said first volume, and
third means coupled to said first volume for venting air from said volume when said apparent refrigerant temperature indicated by said second means is greater than said actual refrigerant temperature indicated by said first means.

In a system for handling refrigerants of multiple predetermined types that includes a storage vessel and means for feeding refrigerant of one of said types to said vessel, means for purging air from said vessel comprising:

a refrigerant bulb containing a reference refrigerant and means positioning said bulb in heat-transfer relationship with refrigerant in said feeding means such that said reference refrigerant generates a vapor pressure coordinated with temperature of refrigerant in said feeding means, and
differential pressure means having a first pressure input coupled to said vessel and a second input coupled to said bulb, said differential pressure means providing an output that indicates presence of air within said vessel as a combined function of pressure differential between said first and second inputs, respectively responsive to refrigerant/air pressure within said vessel and reference refrigerant vapor pressure within said bulb, and saturation pressure/temperature characteristics of the specific type of refrigerant in said vessel.

Dependencies are inferred from the claim text.

Refrigerant handling system with air purge and multiple refrigerant capabilities

Life of this patent

Refrigerant handling system with air purge and multiple refrigerant capabilities

Life of this patent

Abstract

Claims15