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US5377496A Expired / Lapsed US ⏱️ 0.0 years remaining

Refrigeration system with installed acid contamination indicator

Assignee: Carrier Corp
•
Filing: 1993-10-05
•
Granted: 1995-01-03
•
Expires: 2013-10-05
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Abstract

Abstract An improved vapor compression refrigeration system that has an indicator for detecting the presence of acid contamination in the refrigerant contained in the system. The indicator is permanently or semipermanently installed so that continuous monitoring of the refrigerant for acid is possible. The indicator is located in a portion of the system where the refrigerant is always in a gaseous state. In a preferred embodiment, the indicator is located in a bypass line between the suction and the discharge of the system compressor. The indicator preferably shows the presence of acid by a color change, visible from a point external to the indicator, in an indicator bed in the indicator. The color change may be either permanent or the indicator bed may return to its original color when the acid contamination is no longer present in the refrigerant.

Inventors

  • 👤 Nancy M. Otto
  • 👤 Warren R. Clough
  • 👤 Henry B. Balduzzi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 15:55
CPC Classifications
G; G01; G01N; G01N31/00; G01N31/22; G01N31/221; F; F25; F25B; F25B41/00; F25B41/006

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 79 words
An improved vapor compression refrigeration system (10, 10') of the type in which a compressor (11), having a suction (23) and a discharge (22), circulates refrigerant through a closed loop and in which there is a portion of said closed loop where, during operation, said refrigerant is in a gaseous state, the improvement comprising: an indicator (30, 30') for detecting the presence of acid contamination in said refrigerant located in a bypass line between said suction and said discharge.
Claim 2
Dependent Claim 79 words
An improved vapor compression refrigeration system (10, 10') of the type in which a compressor (11), having a suction (23) and a discharge (22), circulates refrigerant through a closed loop and in which there is a portion of said closed loop where, during operation, said refrigerant is in a gaseous state, the improvement comprising: an indicator (30, 30') for detecting the presence of acid contamination in said refrigerant located in a bypass line between said suction and said discharge.
Claim 3
Dependent Claim 26 words
The refrigeration system of claim 1 in which said indicator contains an indicating bed (31) that changes color if there is acid present in said refrigerant.
Claim 4
Dependent Claim 52 words
The refrigeration system of claim 2 in which the change in color of said indicator bed occurs only when there is acid present in the refrigerant passing through said indicator bed and the color of said indicator bed returns to its original color when there no longer acid present in the refrigerant.
Claim 5
Dependent Claim 25 words
The refrigeration system of claim 3 in which said indicator bed comprises meta-cresol purple blue in a glycerol film deposited on a silica sand base.
Claim 6
Dependent Claim 36 words
The refrigeration system of claim 2 in which the color to which said indicator bed changes in the presence of acid is permanent and remains even if there is no longer acid present in the refrigerant.
Claim 7
Dependent Claim 26 words
The refrigeration system of claim 5 in which said indicator bed comprises bromophenol blue sodium salt in a glycerol file deposited on a silica sand base.
Claim 8
Dependent Claim 25 words
The refrigeration system of claim 1 in which said indicator has means (37) for viewing said indicating bed from a point external to said indicator.
Claim 9
Dependent Claim 26 words
The refrigeration system of claim 7 in which said indicator has a casing (34) and said viewing means comprises a transparent wall portion in said casing.
Claim 10
Dependent Claim 27 words
The refrigeration system of claim 1 in which said indicator further comprises an indicator bed that is in downstream refrigerant flow relationship with a flow restrictor (52).
Claim 11
Dependent Claim 26 words
The refrigeration system of claim 9 in which said indicator further comprises a filter (41) that is in upstream refrigerant flow relationship with said flow restrictor.

References Cited (Backward Citations)

US3084658A Cited
DE2353972A1 Cited
US4923806A Cited
US5071768A Cited
US5127433A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-01-02 1998-07-04 1999-01-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-01-02 2002-07-04 2003-01-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-01-02 2006-07-04 2007-01-03 $7700.00 Window Closed / Lapsed

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