GB2346682A

GB2346682A - Refrigerant recovery apparatus

Info

Publication number: GB2346682A
Application number: GB0002525A
Authority: GB
Inventors: Peter Banks; Paul Evison; Daniel Crabb
Original assignee: CLIMATEMASTER Ltd
Current assignee: CLIMATEMASTER Ltd
Priority date: 1999-02-04
Filing date: 2000-02-04
Publication date: 2000-08-16
Anticipated expiration: 2020-02-04
Also published as: GB9902429D0; GB0002525D0; GB2346682B

Abstract

Apparatus for the recovery of refrigerant in liquid, gaseous or mixed form from a storage area (2), includes a compressor (8) and condenser (16) which allows the refrigerant to be received for subsequent use (at 18) in a liquid form as required. A heating vessel (6) into which refrigerant enters prior to entering the compressor heats the refrigerant into a gaseous form before entering the compressor. In one form the heating of the vessel is achieved by passing the outlet pipe (10) from the compressor (8) through the vessel (6). The inlet pipe supplying refrigerant into the vessel (6) extends around the periphery of the inner wall of the vessel, and sprays refrigerant via apertures into the centre of the vessel (6). Oil may then be collected from the base of the vessel. A sensor is able to detect the condition of the refrigerant entering the apparatus. If the refrigerant is in vapour form only, it may flow directly from the compressor to the condenser, bypassing the heating vessel.

Description

Refrigerant Retrieval and/or Transfer Apparatus The invention to which this application relates is apparatus for recovering or retrieving and/or transferring refrigerant from refrigeration system/systems or storage devices.

From time to time it is necessary to remove refrigerant from a refrigeration system to allow perhaps a problem in the refrigeration system to be dealt with, new or additional parts or components to be added to the refrigeration system or simply to allow the replacement of the refrigerant with a more environmentally friendly refrigerant. At the present time, there is available apparatus which includes a means for pumping out the refrigerant vapour/liquid, which is required to be in a gas/vapour form at entry into the compressor and, from the compressor through a condenser and into the collection means so that the refrigerant, when it exits from the apparatus into the storage means is in a liquid form having passed through the condenser. However, for the compressor to operate, and particularly with reciprocating compressors, it is vital that the refrigerant is in a gas/vapour form, hereinafter referred to as gas, and therefore care is required to ensure that the refrigerant which is entering the apparatus is gaseous. However, in practise, it is found that insufficient care is taken and/or that there is an opportunity for liquid to be trapped within the gas and hence pass into the apparatus. As soon as liquid passes into the compressor the compressor can fail and so the apparatus as a whole fails. It is found in practise that there is a high failure rate for this type of apparatus which can be expensive for the refrigeration plant operators and frustrating, as it means that they may have a half empty refrigeration plant which they cannot use for an extended period of time which represents a loss of revenue.

The aim of the present invention is to provide improved apparatus which has a significantly reduced risk of failure and has the ability to ensure that the refrigerant which enters the compressor is in a gaseous state thereby preventing failure of the compressor.

In a first aspect of the invention there is provided apparatus for the recovery and/or transfer of refrigerant from a refrigeration system and/or storage, said apparatus comprising an inlet through which the refrigerant enters the apparatus, a compressor into which the refrigerant enters and a condenser through which the refrigerant enters from the compressor and an outlet through which liquid refrigerant leaves the apparatus and wherein prior to the compressor there is provided a vessel which can be heated to a sufficient temperature to cause any liquid refrigerant in the same to change into a gas.

The apparatus of the invention therefore ensures that any liquid refrigerant enters the vessel to be changed into a gas so that all refrigerant which enters the compressor is in a gaseous form thereby significantly reducing the risk of failure of the compressor as no liquid can enter the same. Typically the said vessel includes a significant proportion of gas at any one time as the majority of the refrigerant which enters the vessel will be in a gaseous state already.

However, any liquid which enters is heated and changed into a gaseous state whereupon the same departs from the vessel through an outlet.

In one embodiment, the heating means for the vessel is provided by at least one outlet pipe from the compressor so that the heat of the heated refrigerant gas as it exits from the compressor, due to the heat of Compression, is used to heat the vessel and hence any liquid in the vessel.

Typically, to improve the heat exchange from the pipe, the same is coiled within the vessel and/or the pipe branches into a plurality of pipes within the vessel each of which can be coiled, and once passed through the vessel, the pipe or pipes pass to the condenser.

In an alternative form the vessel may be provided with a heating element which can be used independently or in conjunction with the pipes from the compressor to heat the vessel.

In one embodiment, the inlet pipe into the vessel is positioned around the periphery of the vessel so that when the refrigerant enters the vessel it is effectively sprayed around the periphery of the vessel walls thereby providing a mixing effect on the refrigerant which has two main features. Firstly, it ensures that any liquid in the refrigerant passes down to the base of the vessel to be heated and secondly it also ensures that any oil, which typically is present in the refrigerant, is separated and again trickles down the side walls of the vessel to be collected at the bottom of the vessel. Typically the vessel can be provided with a viewing aperture to allow the level of oil in the vessel to be monitored and removed as and when required.

In one embodiment if liquid or liquid & vapour refrigerant is detected as being recovered then a diverting means is provided to allow flow from the compressor discharge to the pipes to heat the heating vessel and then to the condenser. However if it is detected that the refrigerant is in a gaseous or vapour form only then the refrigerant is allowed to flow from the compressor discharge directly to the condenser as there is no need for the vessel to be heated as there is no liquid to be transferred into vapour/gas.

In a further feature of the invention the apparatus can be utilised to transfer refrigerant between storage devices and or refrigeration systems.

In order to maintain the equilibrium of the system and to provide a quick and efficient start-up of the same, it is preferred that there is provided a suction pressure/temperature monitor at the inlet and also preferably a discharge pressure/temperature monitor at the outlet so that the apparatus is allowed to operate within certain pressure/temperature parameters.

In a further aspect of the invention there is provided a process for the retrieval and/or transfer of refrigerant, said process comprising introducing the refrigerant into the process from apparatus or storage from which the same is to be retrieved, passing the refrigerant through a compressor and then through a condenser from which refrigerant in a liquid form leaves for subsequent use and/or storage and wherein prior to the refrigerant entering the compressor the same passes through a heating vessel in which the refrigerant is heated to a sufficient temperature to cause any liquid content in the same to be converted into a gaseous form.

Specific embodiments of the invention will now be described with reference to the accompanying drawings, wherein: Figure 1 illustrates a diagram of the system in one embodiment of the apparatus according to the invention; Figure 2 illustrates the arrangement of the inlet pipe in the heated vessel according to one embodiment of the invention; and Figure 3illustrates a further embodiment of the system and apparatus according to the invention.

Referring firstly to Figure 1, there is illustrated apparatus according to the invention wherein said apparatus comprises an inlet pipe 2 which is fitted to the refrigerant bottle or a refrigeration plant to draw refrigerant from the same, a pressure/temperature suction control means 4 which causes control of the suction pressure/temperature at the inlet within particular parameters and which leads to a heated vessel 6 into which the refrigerant flows and the operation of which will be explained in more detail later. From the vessel 6, the refrigerant passes to a compressor 8 and from the compressor the outlet pipe 10 leads back to the heated vessel 6 in this embodiment and enters the same as shown at 14. The pipe is coiled at 14 and serves to heat the refrigerant within the vessel 6.

From the vessel the pipe or pipes leads to a condenser unit 16 at which the refrigerant is cooled so that when it leaves the exit pipe 18 via discharge pressure/temperature monitor and means 17 for collection/storage it is in a liquid form.

Returning now to the heated vessel 6 the refrigerant which enters the same is desired to be in a gaseous form but this is not always the case in practise. Thus, the vessel is provided with heating means, in this case in the form of the pipes 14 from the compressor as shown, so that the heated refrigerant in the pipe 14 serves to heat the interior of the vessel and hence heat the refrigerant so that if any liquid refrigerant enters the vessel it is heated and formed into a gaseous state so that the refrigerant which leaves the vessel is in a gaseous state. This in turn means that any refrigerant which enters the compressor is in a gaseous state and hence overcomes the risk of failure of the compressor due to liquid entering the same. Thus, the invention allows what was a previously significant problem and cause of a significant failure rate of the apparatus to be overcome.

The use of the compressor pipes as shown in 14 represents an efficient way of heating the vessel to a sufficiently high temperature and therefore provides an efficient and economical way of heating rather than using a separate heating element and powering the same although these can be incorporated if required.

To further improve the use of the vessel 6, Figure 2 illustrates the inlet pipe 20 into the vessel. This inlet pipe supplies the refrigerant into the vessel around the periphery of the inner wall of the vessel and is provided with a plurality of apertures through which the refrigerant leaves the inlet pipe and enters the vessel 6. The apertures create a spraying effect which ensures that firstly any liquid passes to the bottom of the vessel to be heated and changed into a gas and also any oil which is present in the refrigerant, which is commonly the case, is sprayed against the walls of the vessel and trickles down the same to be collected at the base and removed from the vessel at regular intervals via outlet 22 shown in Figures 1 and 3 and hence is separated from the refrigerant as required.

Referring now to Figure 3 there is shown a further embodiment of apparatus of the invention which uses the same reference numerals for the components which are common with those of Figure 1 and also additionally shows an embodiment where the flowpath of the refrigerant through the circuit is dependent on whether the refrigerant is in vapour, liquid or a combination of both liquid & vapour forms when entering the apparatus. If liquid or liquid & vapour refrigerant is detected as being recovered at the inlet to the apparatus then the diverting device/devices 30,31 are arranged to allow refrigerant flow from the compressor 8 discharge 10 through the pipes 14 in the vessel 6 and then to the condenser 16 as indicated by arrows 33. However if it is detected that the refrigerant is in vapour only form then the refrigerant is allowed to flow from the compressor 8 discharge 10 to the condenser as indicated by arrow 35 as there is no need for the vessel to be heated as there is no liquid to be heated to change it into vapour/gas. A refrigerant sensing means can be provided in the pipeline, typically before the vessel 6 to identify the condition of the refrigerant as it enters the apparatus and hence allow the selective control of the path of the refrigerant as it leaves the condenser.

It should be appreciated that the vessel 6 or recuperator as it may otherwise be referred to, can be constructed in such a manner and fitted with such devices as are required to fully comply with the regulations appertaining to pressure vessels within the countries it is to be used.

The apparatus of this invention is significantly more efficient than previous apparatus and has a significantly reduced failure rate.

With selection of the appropriate components it has also been found that the apparatus of the invention can be used to remove up to 100 kgs per hour of refrigerant from the refrigeration system in comparison with conventional apparatus which typically can only remove 35 kgs per hour and again has a higher rate of failure. The apparatus is particularly appropriate to being built as a unit which can be portable between sites and can be built so as to pass through standard doorways and thereby allow the same to be easily portable between uses and installed for use. It is also envisaged that the apparatus can be powered by connection to various electrical supply voltages e. g. 110v, 240v, 415volt and others as required and importantly the failure rate of the apparatus according to the invention is significantly reduced in comparison to conventional apparatus.

Claims

Claims 1. Apparatus for the recovery and/or transfer of refrigerant from a refrigeration system and/or storage, said apparatus comprising an inlet through which the refrigerant enters the apparatus, a compressor into which the refrigerant enters and a condenser through which the refrigerant enters from the compressor and an outlet through which liquid refrigerant leaves the apparatus and wherein the apparatus further comprises a heating vessel, positioned prior to the compressor, which heats the refrigerant to a sufficient temperature to cause any liquid refrigerant in the same to change into a gas.
2 Apparatus according to claim 1 wherein the refrigerant which enters the compressor is in a gaseous form.
3. Apparatus according to claim 1 wherein the heating means for the vessel is an outlet pipe from the compressor so that the heat of the heated refrigerant gas as it exits from the compressor is used to heat the vessel.
4 Apparatus according to claim 3 wherein the pipe or a plurality of branch pipes is/are coiled within the vessel.
5 Apparatus according to claim 3 wherein when the pipe or plurality of branch pipes leave the heating vessel they pass to the condenser.
6. Apparatus according to claim 1 wherein the heating means includes a heating element.
7 Apparatus according to claim 1 wherein the refrigerant inlet pipe into the heating vessel is positioned around the periphery of the vessel to allow application of the refrigerant onto the vessel walls.
8 Apparatus according to claim 7 wherein the refrigerant is separated from any oil present in the same.
9 Apparatus according to claim 1 wherein a diverting means is provided to selectively control the flow of the refrigerant from the compressor to the condenser via the heating means.
10 Apparatus according to claim 1 wherein the apparatus includes any or any combination of a suction pressure/temperature monitor at the inlet and/or a discharge pressure/temperature monitor at the outlet so that the apparatus is controlled to operate within certain pressure/temperature parameters.
11. A process for the retrieval and/or transfer of refrigerant, said process comprising introducing the refrigerant into the process from apparatus or storage from which the same is to be retrieved, passing the refrigerant through a compressor and then through a condenser from which refrigerant in a liquid form leaves for subsequent use and/or storage and wherein prior to the refrigerant entering the compressor the same passes through a heating vessel in which the refrigerant is heated to a sufficient temperature to cause any liquid content in the same to be converted into a gaseous form.
12 Apparatus as hereinbefore described with reference to the accompanying drawings.
13. A process as hereinbefore described with reference to the accompanying drawings.