Method of introducing leak detection dye into an air conditioning or refrigeration system including solid or semi-solid fluorescent dyes

Abstract

PCT No. PCT / US95 / 04262 Sec. 371 Date Sep. 21, 1995 Sec. 102(e) Date Sep. 21, 1995 PCT Filed Apr. 6, 1995 PCT Pub. No. WO96 / 07088 PCT Pub. Date Mar. 7, 1996A method of introducing a leak detection dye into a closed refrigeration system through circulation of the refrigerant. A predetermined amount of the leak detection dye, which is soluble in the refrigerant and the system lubricant, is installed in a component of the refrigeration system, such as in a desiccant bag placed in a dehydrator. The leak detection dye may come in various forms including as a leak detection additive having the leak detection dye implanted on and absorbed into a host swatch of a substrate material, as a powder, as a solid pellet of powdered dye concentrate and inert ingredients, or as a slurry. The refrigeration system is assembled, charged and operated, by which the refrigerant and system lubricant flowing through the component, such as a desiccant bag in the dehydrator, and mixes the dye with the refrigerant and system lubricant.

Description

FIELD OF THE INVENTIONThis invention relates generally to the field of detecting leaks in an air conditioning or other refrigeration system and, more particularly, to improved methods of introducing a leak detection dye into the system including the introduction of leak detection dyes into the system in a solid or semi-solid form.BACKGROUND OF THE INVENTIONThere has long been a need to locate leaks in closed refrigeration systems, originally because the loss of refrigerant reduces the cooling capacity of the system, and increasingly because the refrigerants themselves are potential hazardous or deleterious substances when released to the atmosphere. In particular, the production and use of chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigerants is scheduled for incremental phaseout, and for recovery and recycling in the interim.Various methods have been used for detecting and locating leaks in a refrigeration system. Since a slow leak of refrigerant is essentially s...

AI Technical Summary

Benefits of technology

For that reason, an objective and advantage of the present invention is a method by which the leak detection dye additive is installed in an air conditioning or other refrigeration system before the system is charged with refrigerant. The leak detection dye is released into the refrigerant immediately after the system is charged and operated, in order to reduce the risk of inadvertent contact of the dye on the outside of the system and yet permit quality control leak testing after charging, and remains in the system to permit subsequent leak detection.

is a method by which the leak detection dye additive is installed in an air conditioning or other refrigeration system before the system is charged with refrigerant. The leak detection dye is released into the refrigerant immediately after the system is charged and operated, in order to reduce the risk of inadvertent contact of the dye on the outside of the system and yet permit quality control leak testing after charging, and remains in the system to permit subsequent leak detection.

Another objective and advantage of the present invention is a method which allows leak detection dye additive to be installed and stored in a component of the air conditioning system well prior to assembly of the complete system.

Another objective and advantage of the present invention is a method to pre-install a specific quantity of dye additive which is proportional to the amount of initial charge of the refrigeration or system lubricant, to ensure that a predictable concentration of dye will be introduced.

Further objects, features and advantages of the present invention, will become apparent to those skilled in the art as the invention is more fully understood by reading the accompanying drawings and detailed descriptions.

The present invention provides an improved method of introducing a leak detection dye additive into an air conditioning or other refrigeration system. For brevity, the description of the invention is made herein with reference to an air conditioning system, it being understood that it is applicable to other refrigeration systems as well.

Problems solved by technology

There has long been a need to locate leaks in closed refrigeration systems, originally because the loss of refrigerant reduces the cooling capacity of the system, and increasingly because the refrigerants themselves are potential hazardous or deleterious substances when released to the atmosphere.

If dye additive is inadvertently spilled or rubbed on the exterior of the system, it will be difficult to distinguish between fluorescence from a leak site and that resulting from inadvertent external contact.

While care is normally taken to prevent the refrigerant, lubricant and dye from escaping, the nature of the assembly and charging process creates a risk of spills or inadvertent contamination on clothing or tools.

Since very low concentration of dye is required to produce fluorescence, any dye, dyed refrigerant or oil spilled or rubbed on the exterior of the air conditioning system may cause false leak indications.

In addition, the number of dyes that can be used are limited to those dyes which are sufficiently soluble in order to allow the dye to be placed in a concentrated liquid.

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