Portable refrigerant recycling unit for heat exchange with separate recovery unit

A portable refrigerant recycle unit is disposed adjacent to a recycle (reclamation) unit for receiving excess or waste heat discharged therefrom. Liquid and gas refrigerant (e.g., freon) flow from the unit being evacuated to a heat exchanger. A fan draws discharged heat from the reclamation unit across the fins of the heat exchanger. Liquid freon flowing through the heat exchanger is vaporized as it is heated by the air drawn by the fan containing the heat discharged from unit. Gaseous freon flows from the heat exchanger to an oil seperator. Freon vapor then flows from the oil seperator through a filter to the recycle unit output. The reclamation unit condenses the recycle unit output of vapor freon to a liquid. The liquid freon flows from the output of the reclamation to a refrigerant receiver.

BACKGROUND OF THE INVENTION: 
This invention relates to an apparatus for use when servicing cooling 
systems of the type utilizing a compressible refrigerant as the cooling 
medium. More particularly, this invention relates to a portable 
refrigeration recycling unit for use with a refrigeration reclamation 
(recovery) unit. 
It is well known that the dumping of presently used refrigerants which 
consist of chlorofluorocarbons (CFC) is extremely damaging to the 
environment due to their deleterious effect on the ozone layer. Moreover, 
there is now worldwide agreement on regulating production and use of 
CFC's. As a result, the cost of CFC's, which is already high, will rise 
dramatically. 
Recovery units (also referred to as reclamation units) are known. One such 
recovery unit is disclosed in U.S. Pat. Nos. 4,766,733 and 4,981,020, 
which are incorporated herein by reference. U.S. Pat. Nos. 4,766,733 and 
4,981,022 disclose a refrigerant recovery and charging device which is 
connected between a refrigeration system to be charged or evacuated and a 
standard refrigerant receiver. A portion of the refrigerant being 
evacuated to continuously cool itself as the refrigerant travels between 
the refrigeration system to be evacuated and a storage receiver. As the 
refrigerant is cooled, the pressure thereon drops creating a pressure 
differential from the refrigeration system into the receiver. 
While the terms recovery and reclamation have been used interchangeable 
herein and in U.S. Pat. Nos. 4,766,733 and 4,981,020, it is understood 
that reclamation is generally used for recovered refrigerant that has been 
treated and tested to meet standards for new refrigerant. This definition 
has not been applied in this and the above mentioned patents. 
Recovery/recycle units are known, these units are large, heavy devices 
which are typically mounted on a wheel cart. The recovery/recycle units 
are generally not potable and include the recycle portion even when only 
recovery is desired. 
Two-piece recovery/recycle units are known, these units comprise a recovery 
unit with a dedicated recycle unit. The recycle unit can only be used with 
the selected recovery unit and requires multiple refrigerant and 
electrical interconnections. 
Recycle units are known and include filter and filter/oil separation type 
units. The filter/oil separation units have a dedicated heat source 
sufficient for vaporization of the refrigerant. Accordingly, the recycle 
units are large, heavy units (often on wheel carts) and are not portable. 
The recycle units are designed to accept refrigerant from a recovery tank. 
Despite the large number of reclamation (recovery) units, recovery/recycle 
units, two-piece recovery/recycle units and recycle units available, there 
continues to be a need for lighter more efficient units. 
SUMMARY OF THE INVENTION 
The above-discussed and other drawbacks and deficiencies of the prior art 
are overcome or alleviated by the portable refrigerant recycle unit of the 
present invention. In accordance with the present invention, the recycle 
unit is disposed adjacent to a recycle (reclamation) unit to utilize 
excess or waste heat discharged from the reclamation unit. Utilization of 
the excess heat from the reclamation unit significantly reduces the 
heating requirements of the recycle unit, thereby reducing the overall 
size, weight and cost of the recycle unit. Accordingly, this small, light 
weight recovery unit is truly portable and performs as well as the larger, 
heavier prior art units. 
The recycle unit comprises an input connected to a heat exchanger having an 
oil seperator connected downstream therefrom. Separated oil is collected 
in an oil waste receptacle. A filter is provided downstream from the oil 
seperator. The filter output is connected to the output of the recycle 
unit. 
During operation, the recycle unit is placed adjacent the reclamation unit 
for receiving discharged heat therefrom. Liquid and gas refrigerant (e.g., 
freon) flow from the unit being evacuated to the heat exchanger. A fan 
draws discharged heat from the reclamation unit across the fins of the 
heat exchanger. Liquid freon flowing through the heat exchanger is 
vaporized as it is heated by the air drawn by the fan containing the heat 
discharged from unit. Gaseous freon flows from the heat exchanger to the 
oil seperator. Freon vapor then flows from the oil seperator through a 
filter to the recycle unit output. The reclamation unit condenses the 
recycle unit output of vapor freon to a liquid. The liquid freon flows 
from the output of the reclamation to a refrigerant receiver. The recycle 
unit also provides means for sub-cooling the refrigerant receiver. 
It will be appreciated that the recovery (reclamation) unit may also be a 
recovery/charging unit, whereby once a system has been evacuated and 
serviced it can be recharged with the same freon. It is preferred that the 
refrigerant be cleaned prior to recharging. 
Prior art recovery/recycle units are large, heavy devices which are 
typically mounted on a wheel cart. These units are not portable and 
include the recycle portion even when only recovery is desired. Prior art 
two-piece recovery/recycle units comprise a recovery unit with a dedicated 
recycle units. These recycle units can only be used with the selected 
recovery units and require multiple refrigerant and electrical 
interconnections. Prior art recycle units include filter units and 
filter/oil seperator units. The filter/oil separation units have a 
dedicated heat source sufficient for vaporization of the refrigerant. 
Accordingly, the recycle units are large, heavy units (often on wheel 
carts) and are not portable. Moreover, these prior art recycle units are 
designed to accept refrigerant from a tank (i.e., refrigerant receiver) 
rather than in-line between a refrigeration system for evacuation and a 
recovery unit. 
The above-discussed and other features and advantages of the present 
invention will be appreciated and understood by those skilled in the art 
from the following detailed description and drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, a refrigerant recycle unit 10 in accordance with the 
present invention is shown disposed adjacent to a refrigerant recovery 
(reclamation) unit 12. Recycle unit 10 is disposed adjacent to reclamation 
unit 12 to utilize excess heat discharged from the reclamation unit, as 
will be more fully described hereinafter. Utilization of the excess heat 
from the reclamation unit significantly reduces the heating requirements 
of the recycle unit, thereby reducing the overall size, weight and cost of 
the recycle unit. Accordingly, this small, light weight recovery unit is 
truly portable and performs as well as the larger, heavier prior art 
units. 
The excess heat from reclamation unit 12 is discharged through a plurality 
of vents 14 in a panel 16 of the unit, as is common with known reclamation 
(recovery) units: A plurality of vents (not shown) are found on the rear 
end panel of recovery unit 10 adjacent side 16 of reclamation unit 12 for 
receiving the discharged excess or waste heat. A fan 18 is provided to 
draw the excess heat from reclamation unit 12 through recycle unit 10. 
Recycle unit 10 is compatible with most known reclamation (recovery) units. 
Reclamation unit 12 may be of the type described in U.S. Pat. Nos. 
4,766,733 and 4,981,020 commercially available from Thermaflo, a division 
of American Thermaflo Corporation as "OZ SAVER LIGHT" (a trademark of 
THERMAFLO), however, other recovery (reclamation) units are compatible 
with the recycle unit of the present invention, for example, Dupont 
"RRU30"; National Refrigeration Products "LV1"; Recycling Specialists 
International "LIT'L SUCKER"; Robinair "17625"; and White Industries 
"01640". 
Recycle unit 10 comprises a housing 20 having opposing front and rear 
panels 22, opposing sides panels 24, and top and bottom panels 26. The 
rear panel includes vents for receiving discharge heat from a reclamation 
unit, the front panel has ports 28-32 and power receptacles 34, 36 
disposed thereon. Side panel 24 has a port 38 disposed thereon. Fan 18 is 
mounted over an opening through the top panel. A vented cover 40 having a 
handle 42 is mounted to panel 26. 
Referring now to FIG. 2, a schematic diagram of recycle unit 10 is shown. A 
refrigeration system (not shown) from which a compressible refringement is 
to be evacuated is connected by a line 44 to input port 48 which is 
connected by a line 46 to a heat exchanger 48. Heat exchanger 48 is 
connected by a line 50 to an oil seperator 52 which has a heater 54 
disposed thereabout. Oil seperator 52 is connected by a line 56 to output 
port 29 which is connected by a line 58 to an oil waste receptacle 60. Oil 
seperator 52 is also connected by a line 62 to a filter 64 which is 
connected by a line 66 to output port 30. Filter 64 is preferably a 
Thermaflo "FP100-4", although other commercially available filters may be 
employed (e.g., Sporlan "C-485" or Alco Controls "A2F-D"). 
Recycle unit 10 is connected at output port 30 by a line 68 to an input 
port 70 of reclamation unit 12. An output port 72 of reclamation unit 12 
is connected by a line 74 to a port 76 of a refrigerant receiver 78. 
Refrigerant receiver 78 comprises a known type refrigerant receiver such 
as described in U.S. Pat. Nos. 4,766,733 and 4,981,020. Refrigerant 
receiver 78 is connected at a port 80 by a line 82 to port 31 of recycle 
unit 10. A first capillary tube 84 in recycle unit 10 is connected between 
ports 30 and 31. A second capillary tube 86 in recycle unit 10 is 
connected between port 32 and 33. 
During operation, recycle unit 10 is placed adjacent reclamation unit 12 
for receiving discharged heat from unit 12 as is clearly shown in FIG. 1. 
All ports are opened and liquid and gas refrigerant (e.g. freon) flow from 
the unit being evacuated through lines 44 and 46 to heat exchanger 48. Fan 
18 draws discharged heat from unit 12 across the fins (not shown) of heat 
exchanger 48. Liquid freon flowing through heat exchanger 48 is vaporized 
as it is heated by the air drawn by fan 18 containing the heat discharged 
from unit 12. As discussed hereinbefore, this is an important feature of 
the invention since it eliminates the need of a separate heat source as is 
required in the prior art recycle units. 
Gaseous freon flows from heat exchanger 48 to oil seperator 52. The vapor 
flow velocity of the freon is reduced in oil seperator 52 to allow the oil 
seperator to occur. The separated oil flows through line 56, 58 into oil 
waste receptacle 60. The separated oil also captures any acid contaminated 
oil as the acid has an affinity for the oil. Oil seperator 52 is also 
heated by the air drawn by fan 18 containing the heat discharged from unit 
12. Efficient oil-freon vapor separation is assured by the use of band 
heater 54 about oil seperator 52. Heater 54 further vaporizes any 
remaining liquid freon. However, it will be appreciated, that heater 54 
does not provide heat for the heat exchanger 48 and does not provide 
sufficient heat in and of itself to sufficiently vaporize the refrigerant 
in accordance with the present invention. 
Freon vapor then flows from oil seperator 52 along line 62 through filter 
64 which removes remaining oil, acid and water contaminates while 
providing ten micron particulate filtration of the freon vapor. The 
filtered freon vapor flows from output Port 30 to input port 70 of unit 
12. Reclamation unit 12 provides the motive force for moving the recycled 
refrigerant through the system. Reclamation unit 12 condenses the vapor 
freon to a liquid. The liquid freon flows from output port 72 of unit 12 
to refrigerant receiver 78 via port 76. As is known, a portion of the 
refrigerant in receiver 78 will still be vapor. 
Accordingly, this vapor is drawn from receiver 78 and feedback through unit 
12. Vapor freon in receiver 78 flows from port 90 to port 31 on recycle 
unit 10. This vapor passes through capillary tube 84 which restricts the 
vapor flow from receiver 78. Restricted vapor flow from tube 84 is 
combined with the filtered vapor flow in line 66 at a tee 88 and condensed 
to a liquid in unit 12 and flows into receiver 78 as described above. This 
feedback loop results in sub-cooling of receiver 78. While it is preferred 
that receiver 78 be continuously sub-cooled, as described above, the 
sub-cooling can be shut off by closing port 80 and/or port 31. Also 
intermittent sub-cooling of receiver 78 can be accomplished by closing 
port 44 and allowing unit 12 to suck vapor from receiver 78 through tube 
84, whereby only the vapor from receiver 78 is condensed to a liquid in 
unit 12 and returned to receiver 78. 
In the event the reclamation unit 12 is not sufficiently condensing the 
freon vapor a pressure drop can be added in line 74 (i.e., the fluid 
output of unit 12). Although not shown, this is accomplished by connecting 
port 72 of unit 12 to port 32 of unit 10 and connecting port 33 of unit 10 
to port 76 of receiver 78. This basically introduces capillary tube 86 
into line 74. This pressure drop will force unit 12 to further condense 
the outlet freon flow, whereby mostly liquid freon (i.e., refrigerant) 
will enter receiver 78. 
Referring to FIG. 3, an electrical schematic for recycle unit 10 is shown. 
Receptacle 36 is preferably a 110 volt 5 amp receptacle. Receptacle 36 is 
connected by signal lines 90, 92 to fan 18 and heater 54. A switch 94 is 
provided in line 90 to actuate fan 18 and heater 54. It will be 
appreciated that recycle unit 10 does not require any electrical 
connection to reclamation unit 12. 
While unit 12 has only been described for recovery (reclamation) it is 
known in the art that the unit may also be a charging unit, for example, 
as described in U.S. Pat. Nos. 4,766,733 and 4,981,020. More specifically, 
once a system has been evacuated and serviced it can be recharged with the 
same freon. While it is known to recharge systems with the old 
refrigerant, it is preferred that the refrigerant be cleaned prior to 
recharging. The portable recycle unit of the present invention adds this 
cleaning capability to prior art reclamation (recovery)/charging units. 
Recycle unit 12 is versatile in that it is directly compatible with prior 
art reclamation (recovery)/charging units having a vented heat exhaust and 
refrigerant inlet and outlet connections. Further, it is truly porable 
since it weighs less than twenty pounds. Units in excess of thirty-five 
pounds are typically difficult to handle, particularly when climbing 
ladders, as is often required since many cooling (refrigeration) systems 
are located on roofs. 
Accordingly, the recycle unit of the present invention provides many 
advantages over the prior art: 
(1) the recycle unit is universal in that it can be used with any recovery 
system (as described hereinbefore), 
(2) the recycle unit is truly portable; 
(3) the recycle unit eliminates the need of a separate heating unit for 
vaporizing the liquid refrigerant since it utilizes discharged waste heat 
from the recovery unit; and 
(4) the recycle unit is lighter and less expensive as a result of the 
elimination of the separate heating unit. 
While preferred embodiments have been shown and described, various 
modifications and substitutions may be made thereto without departing from 
the spirit and scope of the invention. Accordingly, it is to be understood 
that the present invention has been described by way of illustrations and 
not limitation.