Apparatus for detecting and removing contaminants from a refrigeration system

A device for detecting and removing contaminants from charged refrigeration systems comprising conduit means temporarily communicating the high pressure liquid line of the system with the lower pressure suction line, the conduit means having means for visually determining the moisture content within the refrigerant charge, filter means for removal of the contaminant and a pressure differential means for allowing the refrigerant to return into the system in low pressure gas form. Means are also provided for selectively introducing into the conduit means a sufficient amount of new charge to replace the contaminated charge which is removed from the system by the filter means.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to refrigeration systems and, more particularly, to 
a device for removing contaminants from a charged refrigeration system and 
introducing additional refrigerant into the closed system. 
2. Description of the Prior Art 
Normally in charged refrigerant systems, such as air conditioning 
equipment, if moisture or other contaminants are found in the refrigerant 
(such as freon) in the system, the entire amount of refrigerant is 
discharged into the air and a new supply of charging material is 
introduced into the system. This is a costly and wasteful method of 
ridding the refrigerant system of contaminants. 
Kelley, U.S. Pat. No. 2,214,698, issued Sept. 10, 1940 shows an apparatus 
for charging a system with refrigerant and lubricants. Sporano, U.S. Pat. 
No. 3,232,070, issued Feb. 1, 1966 discloses an apparatus for withdrawing 
and storing refrigerant from a disabled unit. Elsey, U.S. Pat. No. 
2,341,439, issued Feb. 8, 1944 discloses a method of reclaiming the 
refrigerant of a refrigerating system. None of the prior art devices 
provide a means for repairing a closed, charged refrigerant system while 
it is continuing to operate in order to remove contaminants therefrom and 
to add new refrigerant thereto. 
SUMMARY OF THE INVENTION 
The disadvantages of the prior art are overcome by the present invention, 
which provides an apparatus for detecting and removing contaminants in a 
pre-charged refrigerant system and also provides means for selectively 
introducing into the system an amount of refrigerant equal to the 
contaminated refrigerant that has been removed therefrom. The invention is 
used in connection with standard refrigerant systems having a liquid or 
compressed refrigerant which carries the refrigerant from the compressor 
and a low pressure or suction line which carries vaporized refrigerant 
from the evaporator. The apparatus includes a conduit which attaches at 
one end to the liquid line and at the other end to the suction line. Some 
of the high pressure refrigerant liquid passes from the liquid line into 
the conduit. 
A sight glass with a moisture indicator allows the operator to visually 
detect any contaminants in the refrigerant. The refrigerant then passes 
through a liquid line filter dryer where some of the contaminants are 
removed and then into a refrigerant metering device which provides a 
pressure differential between the high pressure side of the line and an 
evaporator coil within the conduit. The refrigerant, now at a lower 
pressure after it passes through the evaporator coil, passes through a 
suction line dryer and into the suction line of the system. The appartus 
is operated continually for a 24-48 hour period, during which time 
substantially all of the refrigerant will have passed through the 
apparatus and various contaminants will have been removed therefrom. 
Also located in the conduit is a manifold which is connected to a source of 
new refrigerant. If a significant amount of contaminated refrigerant is 
removed from the system, a fresh supply of refrigerant may be selectively 
introduced into the system through the manifold. 
It is, therefore, a primary object of the present invention to provide a 
means for detecting and removing refrigerant contaminants from pre-charged 
refrigerant systems without disrupting the operation of the systems. 
Another object of the present invention is to provide a means for cleaning 
the charging material of an air cooled air conditioning or refrigeration 
system while the system continues to operate. 
A further object of the present invention is to provide a means for 
selectively introducing fresh refrigerant into a pre-charged cooling 
system. 
Another object of the present invention is to provide a portable apparatus 
which can be utilized by refrigeration repairmen to detect and remove 
moisture and other contaminants from pre-charged (factory charged) air 
cooled air conditioning and refrigeration systems. 
A still further object of the present invention is to provide a device 
which will help to extend the life of the compressor of a refrigeration 
system. 
Another object of the present invention is to provide a device which will 
eliminate the discharge into the atmosphere of a contaminated refrigerant.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to the Figure of the drawing, the numeral 10 represents the 
device of the present invention and 11 generally represents a standard, 
closed refrigerating apparatus of the type having a motor, compressor, 
evaporator, condenser, and various associated, valves and pipes. The 
cooling agent which flows through the refrigerating apparatus 11 is a 
liquid refrigerant, such as freon. Two of the pipes include a liquid or 
compressed refrigerant line 12 which carries the refrigerant at a high 
pressure from the motor-compressor unit of refrigerating apparatus 11 and 
a suction or low pressure line 13 which carries vaporized refrigerant from 
the evaporator portion of apparatus 11. 
For a variety of reasons, the refrigerant of apparatus 11 may become 
contaminated with moisture acid and/or other contaminants, thus affecting 
the cooling efficiency of the refrigerant and the refrigerating apparatus 
11. In order to rid the apparatus 11 of those contaminants while still 
allowing the apparatus to operate normally, the device 10 can be installed 
on the refrigerating apparatus 11 to remove the contaminants therefrom. 
The device 10 comprises a liquid conduit 14 which temporarily communicates 
the liquid line 12 and the suction line 13. The conduit 14 is comprised of 
a liquid tube 15 which is in flow communication at one of its ends with 
the liquid line 12 through service valve 16 and at its other end with the 
intake port 17 of a manifold 18. A discharge tube 19 is connected to the 
outlet port 20 of manifold 18 and carries the refrigerant through a sight 
glass 21 which has a moisture indicator therein. 
From the sight glass 21, the refrigerant passes into a liquid line 
filter/dryer 22 which may or may not have a removable filter core (not 
shown). From filter/dryer 22, the refrigerant passes through a metering 
means which is in the form of a capillary tube 23 that provides a pressure 
differential between the high pressure side of conduit 14 and the low 
pressure side which is provided by means of evaporator coil 24 which acts 
as an expansion chamber wherein the pressure of the refrigerant is 
reduced. The low pressure refrigerant then passes from coil 24 into the 
suction line cleanup filter/dryer 25 which may or may not have a removable 
core and then through suction tube 26 into the suction line 13 through 
suction line service valve 27. 
The manifold 18 includes an intake cut-off valve 28 which adjusts the flow 
of refrigerant through intake port 17 into the manifold 18. The pressure 
of the incoming refrigerant, measured in pounds per square inch is 
indicated by intake gauge 29. A similar discharge cut-off valve 30 is 
provided on manifold 18 adjacent the discharge port 20. The discharge 
pressure gauge 31 meters the discharge flow rate of the outgoing 
refrigerant. 
A refrigerant port 32 is located on manifold 18 between ports 17 and 20 and 
is in communication through refrigerant tube 33 with a supply of new 
refrigerant in container 34. The amount of new refrigerant entering the 
manifold 18 is controlled by on-off valve 35. 
OPERATION 
The device 10 can be of use to air conditioning/refrigeration service 
personnel, particularly on systems which do not have pump down 
capabilities. While the refrigerating apparatus 11 continues to operate, 
conduit 14 is connected to the apparatus 11 by means of liquid tube 15 
being attached through valve 16 to liquid line 12 and by means of suction 
tube 26 being connected to suction line 13 through valve 27. Some of the 
high pressure refrigerant passes from liquid line 12 into liquid tube 15 
and into manifold 18 through inlet port 17. The flow rate into the 
manifold 18 may be selectively adjusted by valve 28. 
The refrigerant passes through outlet port 20 into discharge tube 19 where 
it passes through sight glass 21. The operator can visually detect by 
means of sight glass 21 the degree, if any, of contamination of the 
refrigerant by inspecting the refrigerant for particles and discoloration. 
The moisture indicator on the sight glass 21 will detect any moisture 
present in the refrigerant. From the sight glass 21, the refrigerant 
passes into the liquid line filter/dryer 22 wherein some of the 
moisture/acid and particles are removed. 
The liquid refrigerant, still under pressure, then enters the capillary 
tube 23 which has a restricted diameter and then passes into the 
evaporator coil 24 wherein the refrigerant expands and loses pressure. The 
refrigerant absorbs heat for evaporation from the warm air discharge from 
the air cooled condensing unit of apparatus 11. In the case of heat pumps 
in the heating cycle, the heat of evaporation can be provided by oil, gas 
or electrical heat source. 
The low pressure refrigerant, now in the gaseous phase, goes into the 
suction line cleanup filter/dryer 25 to remove more moisture/acids and 
other contaminants. From the filter/dryer 25, the refrigerant is 
discharged back into the apparatus 11 through suction tube 26, service 
valve 27 and into suction line 13. 
If it is desired to inject fresh refrigerant into the apparatus 11, valve 
28 or valve 16 can be closed to stop refrigerant from apparatus 11 from 
entering into the manifold 18. Valve 35 can be opened to allow the new 
refrigerant from container 34 to pass through refrigerant tube 33 into 
refrigerant port 32 whereby the new refrigerant enters manifold 18 and 
conduit 14. The refrigerant port 32 should be upstream from outlet port 
20. When a sufficient supply of fresh refrigerant has entered the system, 
valve 35 is closed and valve 28 or valve 16 can be opened to allow the 
refrigerant discontamination process to continue. Port 32 can be capped if 
it is not desired to have new refrigerant enter the system. 
The device 10 can be connected to apparatus 11 for a time sufficient to 
allow all of the refrigerant within apparatus 11 to pass through device 
10. Normally, 24-48 hours will be enough time. The tubes 15, 26 are 
detached from respective service valves 16 and 27 in order to disconnect 
the device from the apparatus 11. The tubes 15, 33, 19 and 26 can be 
standard refrigeration hoses. 
Various modifications of device 10 can be effected without changing its 
overall utility and function. Such modifications include the deletion of 
one of the dryers 22 or 25. Additionally, the manifold 18 can be elimated 
and substituted in its place a conventional three-way valve 
interconnecting tubes 14, 19 and 33. 
For purposes of removing contaminants only, tube 19 may be connected to 
valve 16 eliminating manifold 18 completely, as capacity of metering 
device 23 can vary with cooling capacity of apparatus 11.