REFRIGERANT PROCESSING AND CHARGING SYSTEM

Abstract: For use in processing an object refrigerant produced from an original refrigerant, a refrigerant processing system comprises a separating unit (18, 20, and 22) for separating the original refrigerant into a gaseous phase refrigerant component and a liquid phase refrigerant component. A first supplying pipes (12a) supplies the gaseous phase refrigerant component as the object refrigerant to a liquefying unit (24a and 24b) which liquefies the object refrigerant into a liquefied object refrigerant by the use of evaporation of a liquid refrigerant. A second supplying pipe (12b) supplies the liquid phase refrigerant component to the liquefying unit as the liquid refrigerant. The separating unit may comprise a receiving unit (18) for receiving the original refrigerant as a received refrigerant, a condensing unit (20) for condensing the received refrigerant into a condensed refrigerant, and a separation vessel (22) comprising upper and bottom parts defining upper and bottom spaces, respectively. In this case, the upper and the bottom spaces is contiguous to each other to form a hollow space in the separation vessel.

Description: This invention relates to a refrigerant processing apparatus. More particularly, this invention relates to an apparatus which is operable in a self-heat exchanging system. A refrigerant, such as a fluorocarbon refrigerant, is commonly employed in an air conditioner of an automobile or a refrigerator. A refrigeration system will operate most efficiently when the refrigerant is pure and relatively free of pollutants, for example, oil, air and water. However, the refrigerant becomes impure by pollutants during use. Therefore, it is necessary to periodically remove and recharge the refrigerant within the refrigerant system. Various refrigerant processing and charging systems are already known, for example a refrigerant charging system of the type disclosed in JP-A-63-251767, by Miyata et al. Such a refrigerant charging system comprises a liquefying unit which liquefies an object refrigerant into a liquefied object refrigerant in a liquefication vessel by use of an evaporator included in an external freezing circuit or refrigeration circuit. The liquefied object refrigerant is dropping from the liquefication vessel into a storage container by gravitational force thereof to thereby be charged to the storage container. The object refrigerant is produced from an original refrigerant which is employed in, for example, an air conditioning system. The evaporator, however, is operated by the external freezing circuit, and it is problematic to inevitably need the external freezing circuit for liquefying the object refrigerant. In addition, it can be assumed that liquefied refrigerant is not smoothly charged to the storage container until the liquefied refrigerant is fully accumulated in the liquefication vessel. US-A-4 768 347 discloses a refrigerant recovery system including a compressor having an input coupled through an evaporator and through a solenoid valve to the refrigeration system from which refrigerant is to be withdrawn, and an output coupled through a condenser to a refrigerant storage container. However, this prior art document does not suggest that a pressure reduction valve be used for reducing the pressure for supplying the liquid phase refrigerant to the liquefying unit. It is therefore an object of the present invention to provide an improved refrigerant processing and charging apparatus for processing an object refrigerant produced from an original refrigerant to be pure and free of pollutants. It is another object of this invention to provide an apparatus of the type described, which can do without an external freezing circuit to liquefy the object refrigerant as a liquefied object refrigerant of a liquid phase. It is still another object of this invention to provide an apparatus of the type described, which is able to charge the liquefied object refrigerant to a storage container. These objects are attained by an apparatus as outlined in claim 1. Fig. 1 is a block diagram of a refrigerant processing and charging system according to a first embodiment of this invention. A refrigerant processing and charging unit according to an embodiment of this invention is of the type described and operable in a self-heat exchanging system which is connected to an air conditioning system of an automobile. The air conditioning system uses a fluorocarbon refrigerant as an original refrigerant in a freezing circuit (not shown). Referring to Fig. 1, the refrigerant processing and charging unit comprises an inlet valve 11 which is for introducing the original refrigerant from the freezing circuit. The original refrigerant will be introduced as a liquid phase flow and gaseous phase flow to the refrigerant processing unit. When the inlet valve 11 is opened for introducing the original refrigerant from the freezing circuit, the original refrigerant is reached a first filter dryer 13. The inlet valve 11 can be disconnected from the freezing circuit. The first filter dryer 13 is for removing an impurity, moisture, and acid content from the original refrigerant in the manner known in the art. An accumulator 14 is connected to the first filter dryer 13 for accumulating the original refrigerant. The liquid phase flow is accumulated in a bottom part of the accumulator 14, and the gaseous phase flow thereon is supplied to a first oil intercepter 15. The first oil intercepter 15 is to intercept an oil element of the original refrigerant. The intercepted oil element is accumulated in an oil tank 17 through an oil valve 16. The original refrigerant is supplied to a compressor 18 from the first oil intercepter 15. In this event, the original refrigerant is of gaseous phase. The gaseous original refrigerant is compressed in the compressor 18 and is supplied as a compressed refrigerant to a condenser 20 through a second oil intercepter 19. The intercepted oil element is accumulated in another oil tank (not shown). In the condenser 20, the compressed refrigerant is cooled to thereby be condensed as a condensed refrigerant. The condensed refrigerant is supplied to a second filter dryer 21 which is for removing an impurity, moisture, and acid content from the condensed refrigerant. After that, the condensed refrigerant is supplied to a separation vessel 22 and is separated into a gaseous phase refrigerant component and a liquid phase refrigerant component in the separation vessel 22. The separation vessel 22 comprises an upper part and a bottom part defining an upper space and a bottom space, respectively. The upper space and the bottom space is contiguous each other to form a hollow space in the separation vessel 22. As well known in the art, the gaseous phase refrigerant component has superior purity in comparison with the liquid phase refrigerant component. A combination of the compressor 18, the second oil intercepter 19, the condenser 20, the second filter dryer 21 and, the separation vessel 22 is referred to as a separating arrangement. A pipe 12 is for connecting between the inlet valve 11 and the separation vessel 22. The separation vessel 22 has a first outlet port 22a at an upper portion thereof and a second outlet port 22b at a bottom portion thereof. The first outlet port 22a is connected to a liquefication vessel 24a through a first supplying pipe 12a to communicate with a thermal space which is defined by the liquefication vessel 24a. Therefore, the gaseous phase refrigerant component is sent as an object refrigerant from the separation vessel 22 to the liquefication vessel 24b. On the other hand, the second outlet port 22b is connected to an evaporator 24b through an automatic expansion valve 23 and a second supplying pipe 12b. Therefore, the liquid phase refrigerant component is sent as a liquid refrigerant from the separation vessel 22 to the evaporator 24b and is evaporated in the evaporator 24b to carry out cooling of a surrounding area of the evaporator 24b in the manner known in the art. The evaporator 24b is thermally coupled to the thermal space of the liquefication vessel 24a. In this embodiment, the evaporator 24b is contained in the liquefication vessel 24a. As a result, the gaseous phase refrigerant component is cooled in the liquefication vessel 24a by evaporation of the liquid refrigerant, namely, the liquid phase refrigerant component in the evaporator 24b. In other words, heat exchange is carried out between the gaseous and the liquid phase refrigerant components. Therefore, the evaporator 24b may be referred to as a liquefying arrangement. After being evaporated in the evaporator 24b, the liquid refrigerant is returned to the compressor 18 through a returning pipe 12c. A temperature detecting unit 25 is thermally coupled to the returning pipe 12c. The temperature detecting unit 25 is for detecting temperature of the liquid refrigerant at vicinity of the liquefication vessel 24a to produce a temperature signal which is representative of the temperature. Responsive to the temperature signal, the automatic expansion valve 23 is automatically driven to adjust flow amount of the liquid phase refrigerant component. The liquefied object refrigerant is collected at a lower portion of the thermal space of the liquefication vessel 24a. A storage container 26 is placed under the liquefication vessel 24a and is connected to the thermal space through a sending pipe 27. Therefore, the liquefied object refrigerant drips from the liquefication vessel 24a towards the storage container 26 through the sending pipe 27 by gravitational force thereof. As a result, the liquefied object refrigerant is charged in the storage container 26. It is a matter of course that the modified refrigerant has a relatively higher purity in the storage container 26. When the thermal space is not enough of quantity of the liquefied object refrigerant, the liquefied object refrigerant is prevented from charging thereof towards the storage container 26. For controlling quantity of liquid of the thermal space, a liquid level sensor 28 is connected to the liquefication vessel 24a. The liquid level sensor 28 is for detecting a predetermined liquid level to produce a condition signal. The condition signal is sent to an electromagnetic valve 29. The electromagnetic valve 29 is coupled to the sending pipe 27. Responsive to the condition signal, the electromagnetic valve 29 is automatically driven to adjust the movement of the liquefied object refrigerant through the sending pipe 27. A combination of the sending pipe 27, the liquid level sensor 28, and the electromagnetic valve 29 is referred to as a control arrangement. In this event, it is preferable that the condition signal responsive to the predetermined liquid level is produced until the evaporator 24b is made thoroughly wet by the liquefied object refrigerant in the liquefication vessel 24b because of an effectiveness of the heat exchange. When the detected liquid level is lower than the predetermined liquid level, the electromagnetic valve 29 is driven in response to the condition signal to stop the dripping of the liquefied object refrigerant to the storage container 26. When the detected liquid level is higher than the predetermined level, the electromagnetic valve 29 is driven in response to the condition signal to open the sending pipe 27. So that, the liquefied object refrigerant flows into the storage container 26. Preferably, a breathing pipe 30 is disposed between the liquefication vessel 24a and the storage container 26 for breathing a residual gas of the refrigerant in the storage container 26 because of smooth flow of the liquefied object refrigerant. Therefore, the effectiveness of the heat exchange is increased in the liquefying arrangement. The object refrigerant can be smoothly charged into the storage container 26 by a repeat of operation which is described before.

Claims: A refrigerant processing apparatus for use in processing an original refrigerant, said refrigerant processing apparatus comprising separating means (18, 20, 22) for separating said original refrigerant into a gaseous phase refrigerant component and a liquid phase refrigerant component, liquefying means (24a, b) for liquefying said gaseous refrigerant component into a liquefied object refrigerant by use of evaporation of said liquid phase refrigerant component; first supplying means (12a) coupled to said separating means for supplying said gaseous phase refrigerant component to said liquefying means; second supplying means (12b) coupled to said separating means for supplying said liquid phase refrigerant component with a predetermined pressure to said liquefying means; a pressure reduction valve (23) provided in said second supply means upstream of said liquefying means for reducing said predetermined pressure; a storage container (26) being disposed below said liquefying means; and means connecting (27) said liquefying means and said storage container (26) for collecting said liquefied object refrigerant in said storage container. The refrigerant processing apparatus as claimed in Claim 1, wherein said separating means comprises: receiving means (18) for receiving said original refrigerant; condensing means (20) coupled to said receiving means for condensing said original refrigerant into a condensed refrigerant; and a separation vessel (22) comprising an upper part and a bottom part defining an upper space and a bottom space, respectively, said upper and bottom spaces being contiguous to each other to form a hollow space in said separation vessel (22); said separation vessel (22) being coupled to said condensing means (20) and supplied with said condensed refrigerant to separate said gaseous phase refrigerant component and said liquid phase refrigerant component from said condensed refrigerant; said upper part being coupled to said first supplying means (12a); said bottom part being coupled to said second supplying means (12b). The refrigerant processing apparatus as claimed in Claim 1, wherein said liquefying means comprises: a liquefication vessel (24a) defining a thermal space; an evaporator (24b) thermally coupled to said thermal space; said liquefication vessel (24a) being coupled to said first supplying means (12a) to receive said gaseous phase refrigerant component; and said evaporator (24b) being coupled to said second supplying means (12b) to cause evaporation of said liquid phase refrigerant component. The refrigerant processing apparatus as claimed in Claim 3, further comprising controlling means coupled to said liquefying means for controlling the level of said liquefied object refrigerant to charge said liquefied object refrigerant to said storage container, The refrigerant processing apparatus as claimed in Claim 4, wherein said controlling means comprises: detecting means (28) coupled to said liquefication vessel (24a) for detecting the level of said liquefied object refrigerant; and valve means (29) coupled to said detecting means for allowing the flow of said liquefied object refrigerant to said storage container (26).

Inventors: KAMEGASAWA, MASAO, TOMARU, KEIICHI
Applicants: SANDEN CORPORATION
Application year: 1989
Main classification: F25B45
IPC codes: F25B45