Claims
- 1. In an apparatus for reclaiming refrigerant comprising, in combination, means for removing gaseous or liquid refrigerant from a container, vaporizing all of said liquid refrigerant and separating oil from the gaseous refrigerant, a compressor for receiving and compressing said gaseous refrigerant from said container, a condenser for receiving and condensing said gaseous refrigerant from said compressor, and means for receiving and storing said liquid refrigerant from said condenser, the improvement of liquid injection means in fluid communication with said compressor, whereby said liquid injection means inject controlled amounts of liquid refrigerant into said compressor in order to prevent overheating of the compressor.
- 2. The improvement of claim 1, wherein said means for receiving and storing said refrigerant is in fluid communication with said liquid injection means in order to supply liquid refrigerant to the compressor.
- 3. The improvement of claim 1, wherein the addition of said controlled amounts of liquid refrigerant is controlled by valve means that permit injection of liquid refrigerant into said compressor when the pressure in said compressor drops to a certain predetermined level.
- 4. The improvement of claim 3, wherein said valve means is a pressurized diaphragm biased disc valve.
- 5. In an apparatus for reclaiming refrigerant that has cleaning means for holding refrigerant within the apparatus while repeatedly cleaning and cooling the refrigerant said cleaning means comprising, in combination, means for removing refrigerant from a container and separating oil from the refrigerant, a compressor for receiving and compressing said refrigerant from said container, a condenser for receiving and condensing said refrigerant from said compressor, and storage means for receiving and storing said refrigerant, the improvement where said storage means is equipped with float control means, said float control means operating to automatically shut off said means for removing refrigerant from a container when a certain predetermined level of refrigerant is continued within said storage means, said float control means is comprised of switch means attached externally to the storage means, said switch means being in fluid communication with said storage means by first and second conduits, said switch means being positioned at a height such that it will be activated to shut off said means for removing refrigerant from a container when a predetermined level of refrigerant in said storage means is reached.
- 6. The improvement of claim 5, wherein said switch means is comprised of a floating magnet and a magnetically activated switch, said floating magnet is capable of floating on the surface of said refrigerant within the switch means, whereby the raising of said floating magnet within said control means operates to activate said magnetically activated switch.
- 7. The improvement of claim 5 wherein said first conduit is attached to the top of said float control means and to a point somewhat below the upper end of said storage means and said second conduit is attached to the bottom of said float control means and to a point approximately near the middle of said storage means.
- 8. In an apparatus for reclaiming refrigerant that has cleaning means for holding refrigerant within the apparatus while repeatedly cleaning and cooling the refrigerant, said cleaning means comprising, a compressor for compressing and discharging gaseous refrigerant, means for condensing the gaseous refrigerant to a liquid, means for conducting the liquid refrigerant into a closed elongated chill tank, means for withdrawing the liquid refrigerant from the bottom of said chill tank and passing it successively through a filter-drier, expansion means and a fluid conduit within the chill tank extending upwardly from the lower portion of the chill tank, and means outside the chill tank for connecting the fluid conduit in fluid communication with the intake of the compressor, the improvement wherein said expansion means consists of a plurality of expansion valves that are each in fluid communication with said filter-drier and said fluid conduit within the chill tank.
- 9. The improvement of claim 8 wherein the filter-drier is attached to a plurality of conduits leading to said expansion devices, said conduits each being equipped with flow control means upstream from said expansion devices.
- 10. The improvement of claim 9 wherein only one of said flow controls can be activated at a time, whereby liquid refrigerant will flow successively through said filter-drier into only one of said conduits, into the corresponding expansion devise, and into said fluid conduit within the chill tank.
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of copending application Ser. No. 109,958 filed Oct. 19, 1987, for "Refrigerant Reclaim Method and Apparatus."
1. Field of Invention
This invention relates to an apparatus for removing refrigerant from a refrigeration system during repairs, confining it so as to avoid its escape to the atmosphere, separating contaminants from the refrigerant and returning the refrigerant to the repaired refrigeration system or discharging it to a storage container.
2. Background of the Invention
In the past, little attention was paid to the storage or recycling of refrigerant. When refrigeration systems were being repaired or when the refrigerant, such as those sold under the trademark "Freon," was contaminated sufficiently to affect the effectiveness of refrigeration, the refrigerant was vented into the atmosphere.
Recent developments have, however, created a demand for systems capable of storing refrigerant while at the same time purifying the contaminated refrigerant. The United States, as have several other countries, has become a signatory of the "Montreal Protocol on Substances that Deplete the Ozone Layer", which restricts future productions of fully halogenated chlorofluorocarbons. Pursuant to this international mandate, future production of all currently used refrigerants are to be drastically cut by the end of the century. In addition to this development, the United States Environmental Protection Agency has classified several widely used refrigerants as hazardous substances under the Resource Conservation and Recovery Act ("RCRA").
The combination of these two regulatory developments accentuates the necessity for a device which will store and purify refrigerant, eliminating the possibility of unlawful emissions and the necessity for purchasing refrigerants in an artificially constrained market. The present invention relates to improvements on the refrigerant reclaim method and apparatus as described in co-pending U.S. application Ser. No. 109,958 of Van Steenburgh, Jr.
The patent application, Ser. No. 109,958, discloses an apparatus for drawing refrigerant from a container, or a refrigeration system to be repaired, heating the refrigerant sufficiently to maintain it in a gaseous state while it passes through an oil separator into the intake of a compressor. Compressed gaseous refrigerant is discharged from the compressor and passed through a heat exchanger to heat the incoming liquid refrigerant and then passes through to a condenser where it is liquefied. The liquefied refrigerant is passed from the condenser into a hold tank from the bottom of which liquid refrigerant flows through a filter-dryer and an expansion device for reconverting the liquid refrigerant to a gaseous form. From the expansion device the gaseous refrigerant passes through a coil submerged in the liquid in the hold tank and then is passed back to the intake of the compressor. The temperature of the liquid in the hold tank is lowered by the chilling effect of the expanding gaseous refrigerant passing through the coil submerged in the liquid. The refrigerant can be repeatedly passed from the chill tank through the filter-dryer, expansion device, cooling coil, compressor, heat exchanger, condenser and back to the hold tank. This repeated process will progressively lower the temperature of refrigerant in the hold tank, pass the refrigerant through the filter-dryer repeatedly, and, by lowering the temperature of the refrigerant, maximize the separation of air from the refrigerant.
The apparatus described in application Ser. No. 109,958 provides several advantages over the prior art. There are, however, several additional attributes that are desirable in refrigerant reclaim systems.
One difficulty seen in all previous reclaim systems is in preventing "burn out" of the compressor unit. Compressor burn out can result from several conditions. Occasionally, substantial amounts of liquid refrigerant is allowed to enter the compressor. When this "liquid slugging" occurs, the compressor will be destroyed, as the piston rods become bent. This results in the physical destruction of the compressor pistons. Another very common cause of compressor burn out is operation of the compressor with inadequate amounts of oil.
Finally, many compressor burn outs are a result of overheating. Hermetically sealed compressor pumps operate by allowing the cool refrigerant gas to pass directly over and around the electrical coils of the compressor motor. When the compressor is operated without sufficient amounts of cooling refrigerant entering the compressor, the motor will eventually overheat and the electrical coils will be destroyed.
The device disclosed in application Ser. No. 109,958 combines a uniquely designed oil separator with cooling tanks for subcooling the refrigerant. Subcooling of the refrigerant allows for greatly enhanced water and air separation from the refrigerant as well as facilitating the discharge of refrigerant into warmer vessels. Combining the cooling function into the reclaim unit requires the use of refrigerant-specific expansion valves Unfortunately, each of the commonly used refrigerants require a different expansion valve. Since several different refrigerants are often used, for example those refrigerants commonly referred to as R-12, R-22, R-502 and R-500, it would be desirable to incorporate features into a reclaim system whereby the system could easily reclaim several different refrigerants.
A final problem associated with any system that stores refrigerant is in the potential for overfilling storage tanks. Particularly when filling tanks with cooled refrigerant, it is possible to fill a storage tank to such a level that thermal expansion will create a potentially explosive buildup of pressure. Means for monitoring the level of liquid refrigerant in a refrigerant reclaim system is therefore a crucial element. Traditionally, physical means sensitive to pressure buildup are incorporated into such storage tanks. When the pressure exceeds a certain preset level, a valve will open and allow the refrigerant to vent into the atmosphere. Due to the environmental regulations prohibiting the release of refrigerant into the atmosphere, this is a less than satisfactory solution to this problem.
The present invention provides means for drawing refrigerant from a container and removing oil, water and other contaminants. This invention specifically relates to means for preventing the premature destruction of compressor pumps that allow the user to systematically check for oil loss in the compressor by use of a sight glass. This invention also provides means for cooling the compressor electrical coils when a minimal amount of gaseous refrigerant is entering the compressor by injecting a controlled amount of cooled liquid refrigerant directly unto the compressor coils. The present invention also relates to means for monitoring the level of refrigerant in the storage tank in order to prevent over filling by use of an externally attached float device. And, finally, this invention provides means for adapting the refrigerant reclaim system to accept several different refrigerants by including a plurality of expansion valves which can be selectively placed on-line.
The invention can be more fully understood when the detailed description which follows is read with reference to the accompanying drawings.
US Referenced Citations (10)
Continuation in Parts (1)
|
Number |
Date |
Country |
| Parent |
109958 |
Oct 1987 |
|
Patent Grant
4998416
