as) United States
`a2) Patent Application Publication ao) Pub. No.: US 2002/0046568 Al
`(43) Pub. Date:
`Apr. 25, 2002
`Thomaset al.
`
`US 20020046563A1
`
`(54) METHOD OF INTRODUCING
`REFRIGERANTS INTO REFRIGERATION
`SYSTEMS
`
`(76)
`
`Inventors: Raymond Hilton Percival Thomas,
`Pendleton, NY (US); Roy Phillip
`Robinson, Cheektowaga, NY (US);
`Rajiv Ratna Singh, Getzville, NY
`(US); David Paul Wilson, East
`Amherst, NY (US)
`
`Correspondence Address:
`Synnestvedt & Lechner LLP
`2600 Aramark Tower, 1101 Market Street
`Philadelphia, PA 19107-2950 (US)
`
`(21) Appl. No.:
`
`09/943,063
`
`(22)
`
`Filed:
`
`Aug. 30, 2001
`
`Related U.S. Application Data
`
`(63) Non-provisional of provisional
`60/235,746, filed on Sep. 27, 2000.
`
`application No.
`
`Publication Classification
`
`Tints C07 cccccccssssssssssssssessssssessessesesseeeeeee F25B 45/00
`(SL)
`(52) US. Che
`ecceccecssssssssssssssssssseessssssesssesessetesesessessensess 62/77
`
`(57)
`
`ABSTRACT
`
`Provided are methods of introducing environmentally desir-
`able refrigerants into refrigeration systems. The present
`methods involve recharging a refrigerant system that con-
`tains a chlorine-containing refrigerant and a lubricant com-
`prising the steps of (a) removing the chlorine-containing
`refrigerant from the refrigeration system while retaining a
`substantial portion of the lubricant in said system; and (b)
`introducing to said system a composition comprising: (1) a
`refrigerant; (11) a surfactant; and (iii) a solubilizing agent.
`
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`
`METHOD OF INTRODUCING REFRIGERANTS
`INTO REFRIGERATION SYSTEMS
`
`CROSS-REFERENCE TO RELATED
`APPLICATIONS
`
`[0001] This application claims the benefit of U.S. Provi-
`sional Application No. 60/235,746 filed Sep. 27, 2000.
`
`FIELD OF INVENTION
`
`[0002| The present invention relates generally to methods
`of introducing environmentally desirable refrigerants into
`refrigeration systems. More specifically,
`this invention
`relates to methods for removing chlorofluorocarbons and
`hydrochlorofluorocarbons from refrigeration systems and
`charging refrigeration systems with environmentally desir-
`able refrigerant compositions.
`
`BACKGROUND
`
`[0003] The use of chlorine-containing refrigerants, such as
`chlorofluorocarbons
`(“CFC’s”), hydrochlorofluorcarbons
`(“HCFC’s”) and the like, as refrigerants in air conditioning
`and refrigerating equipment has become disfavored due to
`the ozone-depleting properties associated with such com-
`pounds. As a result,
`it has become desirable to “retrofit”
`chlorine-containing refrigeration systems by replacing chlo-
`rine-containing refrigerants with non-chlorine-containing
`refrigerant compounds which will not deplete the ozone
`layer, such as hydrofluorocarbons (“HFC’s”).
`
` non-chlorine-containing
`[0004] Unfortunately, many
`refrigerants, including HFC’s,are relatively insoluble and/or
`immiscible in the types of lubricants used traditionally with
`CFC’s
`(“hydrocarbon-based lubricants”)
`including,
`for
`example, mineral oils, alkylbenzenes or polyalphaolefins.
`This is problematic because in order for a retfrigerant/
`lubricant system to work efficiently within a refrigeration or
`air conditioning system, the refrigerant must be sufficiently
`soluble in the lubricant over a wide range of operating
`temperatures. Such solubility lowers the viscosity of the
`lubricant and allows it to flow more easily throughout the
`system. In the absence of such solubility, lubricants tend to
`become lodged in the coils of the refrigeration system
`evaporator, as well as other parts of the system, and thus
`reduce the system efficiency.
`
`‘To avoid such problems, traditional methods for
`[0005]
`retrofitting refrigeration systems require the steps of: (a)
`removing all chlorine-containing refrigerant and at
`least
`95% of the hydrocarbon-based lubricant from the system;
`followed by (b) introducing to the system a new non-
`chlorine-containing refrigerant composition and a replace-
`ment lubricant compatible therewith.
`
`‘The present inventors have come to appreciate that
`[0006]
`such traditional methods are disadvantageous for several
`reasons. For example, one disadvantage is that removal of
`lubricants, and particularly hydrocarbon-based lubricants
`which have heretofore frequently been used, from a refrig-
`eration system via flushing or other methods tends to be
`time-consuming and costly. Another disadvantage is that
`many replacement lubricants, such as esters, are very sen-
`sitive to moisture and must be handled with great care. Yet
`another disadvantage is that replacement lubricants do not
`perform efficiently certain functions, such as noise reduc-
`tion, which are associated with hydrocarbon-based lubri-
`canis.
`
`[0007| Recognizing these and other drawbacksofthe prior
`art, the present inventors have perceived a need for a new,
`efficient and more desirable method for introducing envi-
`ronmentally desirable refrigerants into refrigeration sys-
`tems. These and other objects are achieved by the present
`invention as described below.
`
`DESCRIPTION OF THE INVENTION AND
`PREFERRED EMBODIMENTS
`
`(0008| The present invention is directed to methods of
`introducing environmentally desirable refrigerants
`into
`refrigeration systems. The methods of the present invention
`overcome the disadvantages of the prior art by facilitating
`the introduction of environmentally desirable, non-chlorine-
`containing refrigerant compositions into refrigeration sys-
`tems without the removal of hydrocarbon-based lubricant
`already present in the system. Accordingly, non-chlorine-
`containing refrigerant compositions can be addedto existing
`refrigeration systems containing hydrocarbon-based ols,
`such as mineral oils or alkyl benzenes, to form efficient and
`environmentally desirable refrigerant/lubricant systems with
`ereater ease and less expense than traditional methods.
`
`the present
`[0009| According to certain embodiments,
`methods involve recharging a refrigerant system that con-
`tains a chlorine-containing refrigerant and a lubricant com-
`prising the steps of (a) removing the chlorine-containing
`refrigerant from the refrigeration system while retaining a
`substantial portion of the lubricant in said system; and (b)
`introducing to said system a composition comprising: (1) a
`refrigerant; (ii) a surfactant; and (411) a solubilizing agent. As
`used herein, the term “substantial portion” refers generally
`to a quantity of lubricant which is at least about 50% (by
`weight) of the quantity of lubricant contained in the refrig-
`eration system prior to removal of the chlorine-containing
`refrigerant. Preferably, the substantial portion of lubricant in
`the system according to the present invention is a quantity of
`at least about 60% of the lubricant contained originally in the
`refrigeration system, and more preferably a quantity of at
`least about 70%.
`
`[0010] According to certain alternative embodiments, the
`present methods involve generally the steps of (a) providing
`a refrigeration system comprising a chamber having therein
`a hydrocarbon-based lubricant and substantially no chlorine-
`containing refrigerant; and (b) introducing to said chamber
`a composition comprising: (i) a refrigerant; (41) a surfactant;
`and (111) a solubilizing agent.
`
`[0011] As used herein the term “refrigeration system”
`refers generally to any system or apparatus, or any part or
`portion of such a system or apparatus, which employs a
`refrigerant to provide cooling. Such refrigeration systems
`include, for example, air conditioners, electric refrigerators,
`chillers, transport refrigeration systems, commercial refrig-
`eration systems and the like.
`
`[0012] Those of skill in the art will recognize that the
`refrigeration systems used in the methods of the present
`invention generally comprise a chamber in which both a
`refrigerant and lubricant are contained and through which
`the refrigerant and lubricant can be circulated. According to
`certain embodiments of the present invention, the removal
`step (a) comprises removing a chlorine-containing refriger-
`ant from a refrigeration system, especially from a chamber
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`within the system, while leaving a substantial amount of
`lubricant, and preferably a hydrocarbon-based lubricant, in
`the system.
`
`[0013] Any of a wide range of known methodscan be used
`to remove chlorine-containing refrigerants from a refrigera-
`tion system while removing less than a major portion of the
`lubricant contained in the system. According to preferred
`embodiments,the lubricant is a hydrocarbon-based lubricant
`and the removal step results in at least about 90%, and even
`more preferably at least about 95%, of said lubricant remain-
`ing in the system. For example, because refrigerants are
`quite volatile relative to traditional hydrocarbon-basedlubri-
`cants (the boiling point of refrigerants are generally under
`10° C. whereasthe boiling point of mineraloils are generally
`over 200° C.), the removal step may readily be performed by
`pumping chlorine-containing refrigerants in the gaseous
`state out of a refrigeration system containing liquid state
`lubricants. Such removal can be achieved in any of a number
`of ways knownin the art, including, the use of a refrigerant
`recovery system, such as the recovery system manufactured
`by Robinair of Ohio. Alternatively, a cooled, evacuated
`refrigerant container can be attached to the low pressureside
`of a refrigeration system such that the gaseous refrigerantis
`drawn into the evacuated container and removed. Moreover,
`a compressor may be attached to a refrigeration system to
`pump the refrigerant from the system to an evacuated
`container. In light of the above disclosure, those of ordinary
`skill in the art will be readily able to remove chlorine-
`containing lubricants from refrigeration systems and to
`provide a refrigeration system comprising a chamber having,
`therein a hydrocarbon-based lubricant and substantially no
`chlorine-containing refrigerant according to the present
`invention.
`
`[0014] The introduction step (b) of the present invention
`comprises introducing to a hydrocarbon-based lubricant a
`composition comprising: (1) a refrigerant; (11) a surfactant;
`and (iii) a solubilizing agent.
`
`[0015] Any of a wide range of non-chlorine-containing
`refrigerants can be used in the present invention. Examples
`of refrigerants suitable for use in the present
`invention
`include HFC’s,
`such as 1,1,1,2-tetrafluoroethane (“R-
`134a”), pentafluoroethane (“R-125”), difluoromethane (“R-
`32”), isomers of trifluoroethane (“R-143” and “R-143a”),
`isomers of pentafluoropropane (for example, “R-245fa”,
`“R-245ea”, “R-245ca”
`and “R-245eb”),
`and mixtures
`thereof,
`such as, R-407A, R-407B, R-407C, R-410A,
`R-404A, R-507A, R-508A and R-S508B.
`
`[0016] The surfactant used in the present invention can be
`any surfactant which, when added to a composition com-
`prising a hydrocarbon-based lubricant component and a
`non-chlorine-containing refrigerant component,
`increases
`the solubility or dispersibility of one componentin the other
`by at least 1% (absolute) by weight of the lubricant/refrig-
`erant composition. Preferably, the surfactant used increases
`the solubility or dispersibility of one component in the other
`by at least 2 weight % (absolute), and even more preferably
`by at least 5 weight %(absolute). For example, a composi-
`tion of Refrigerant A and Lubricant B is a single phase
`composition when it comprises up to and including, but no
`more than, 10% by weight of composition of Refrigerant A.
`With the addition of a Surfactant C, the same composition
`remains as a single phase composition up to and including
`
`15% by weight of the composition of Refrigerant A. For the
`purposesof the present invention, surfactant C 1s considered
`to increase the solubility of Refrigerant A in Lubricant B by
`5 wt. %.
`
`the surfactant
`In certain preferred embodiments,
`[0017|
`used increases the solubility and/or dispersibility of the
`refrigerant in the hydrocarbon-based lubricant and increases
`the solubility and/or dispersibility of the hydrocarbon-based
`lubricant in the refrigerant. Although applicants do not wish
`to be bound by or to any theory of operation, it is believed
`that the surfactant in such embodiments enhancessolubility
`and/or dispersibility by reducing the interfacial
`tension
`between the two liquid layers. Typically, in such embodi-
`ments, the surfactantis soluble in the lubricant. Accordingto
`certain preferred embodiments, the surfactant is soluble in
`both the refrigerant and the lubricant.
`
`[0018| Examples of surfactants suitable for use in the
`present invention are disclosed in U.S. Pat. No. 5,254,280,
`issued to Thomaset al. and incorporated herein by reference,
`and include: sulfonates;
`long-chain alkyl substituted aro-
`matic sulfonic acids; phosphonates; thiophosphonates; phe-
`nolates; metal salts of alkyl phenols; alkyl sulfides; alky-
`Iphenolaldehyde condensation products; metal salts of
`substituted salicylates; N-substituted oligomers or polymers
`from the reaction products of unsaturated anhydrides and
`amines. Other suitable surfactants include: polyoxyethyl-
`ene-type nonionic surfactants, such as polyoxyethylene
`alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethyl-
`ene aryl ethers, polyalkylaryl ethers, polyoxyethylene fatty
`acid esters, polyoxyethylene sorbitan fatty acid esters and
`polyoxyethylene sorbitol fatty acid esters; copolymers of
`methacrylates with N-substituted compounds, such as N-vi-
`nyl pyrrolidone
`or dimethylaminoethyl methacrylate;
`copolymers which incorporate polyester linkages, such as
`vinyl acetate-maleic anhydride copolymers; and the like.
`The alkyl groups of the polyoxyethylene alkyl ethers are
`preferably straight-chain or branched alkyl groups having
`from about 1 to about 15 carbon atoms which may, option-
`ally, be further substituted with fluorine. The aryl groups of
`the polyoxyethylene aryl ethers are preferably aromatic
`eroups having from about 6 to about 20 carbon atoms. Such
`aromatic groups may, optionally, be further substituted with
`fluorine. According to certain preferred embodiments, the
`surfactant 1s a polyoxyethylene alkyl ether.
`
`[0019] Although applicants do not wish to be bound byor
`to any theory of operation, it 1s believed that solubilizing
`agents according to the present invention act as carriers for
`the surfactant and aid the surfactant in enhancing the mis-
`cibility of hydrocarbon-based lubricants and refrigerants. In
`certain embodiments of the present invention, the surfactant
`is readily soluble in hydrocarbon-based lubricants but sig-
`nificantly less soluble in refrigerants. Accordingly, a solu-
`bilizing agent which is relatively soluble in both hydrocar-
`bon-based lubricants and refrigerants, and in which a
`surfactant of the present invention in soluble, can be used to
`aid transport of the surfactant between lubricant and refrig-
`erant to enhance the miscibility thereof. It 1s further believed
`that both the surfactant and the solubilizing agent indepen-
`dently enhance the solubility and dispersibility of the refrig-
`erant in the lubricant.
`
`(0020| Any of a wide range of solubilizing agents can be
`used in the present invention. Suitable solubilizing agents
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`include polyalkylene glycol lubricants such as straight-chain
`or branched polypropylene glycols, polybutylene glycols,
`and random or ordered copolymers of ethylene oxide, pro-
`pylene oxide, and/or butylene oxide in any combination. The
`polyalkylene glycols may have terminal hydroxyl groups
`and/or terminal moieties for capping one or more endsofthe
`molecule. Suitable moieties for capping polyalkylene glycol
`of the present invention include: fluorinated alkyl or aryl
`eroups; non-fluorinated alkyl or aryl groups; ester groups,
`and mixtures thereof. In addition, ester and diester lubricants
`based on acids having straight-chain or branched chains of
`from about 3 to about 15 carbon atoms and alcohols such as,
`for example, pentaerythritol, neopentyl glycol, glycerin, or
`trimethylolpropane are suitable for use as solubilizing agents
`in the present invention. Polyvinyl ethers (PVEs) are also
`suitable as solubilizing agents. PVEs are characterized gen-
`erally by the formula —{|CH,CHOR,|—{ CH,CHOR,|,—
`wherein R, and R, are independently aromatic or alkyl
`eroups containing from about 1 to about 15 carbon atoms
`with at least one of m or n being non-zero and ranging from
`3 to 20. PVEs suitable for use in the present invention may
`optionally be substituted with fluorine or heteroatoms such
`as oxygen, nitrogen and sulfur. In certain preferred embod1-
`ments, the solubilizing agent is a polyalklene glycol having
`more units derived from butylene oxide than propylene
`oxide, and no more than 10 mole percent of ethylene oxide.
`In certain other preferred embodiments,
`the solubilizing
`agents are polybutylene glycols having terminal hydroxyl
`eroups or straight-chain or branched polybutylene glycols
`having organic caps on one or more ends of the molecule,
`such as those disclosed in U.S. Pat. No. 5,154,846, incor-
`porated herein by reference.
`In certain more preferred
`embodiments, the solubilizing agent is a straight-chain or
`branched polybutylene glycol having terminal hydroxyl
`oTroups.
`
`[0021] The viscosity of the solubilizing agents used in the
`present invention may comprise any viscosity suitable for a
`particular application. In certain preferred embodiments, the
`viscosity of the solubilizing agent used in the present
`invention is from about 1 to about 20 centistokes at 100° C.
`More preferably, the solubilizing agent has a viscosity of
`from about 1 to about 10 centistokes at 100° C., and even
`more preferably from about 1 to about 5 centistokes at 100°
`C,
`
`[0022] Procedures for preparing polyalkylene glycols suit-
`able for use in the present invention are well known. For
`example, U.S. Pat. No. 5,254,280, discloses methods for
`preparing polybutylene glycols having fluorinated alkyl
`eroup caps. A wide variety of polyalkylene glycol lubricants
`are also commercially available, for example, polypropylene
`elycols and polybutylene glycols having terminal hydroxyl
`eroups are available form Dow Chemical. Various ester-
`based lubricants are also available commercially, including,
`for example, Mobil EAL 22, an ester lubricant having a
`viscosity of 32 centistokes at 37° C., available commercially
`from Exxon-Mobil.
`
`In addition to the refrigerant, surfactant and solu-
`[0023]
`bilizing agent, the composition introduced into the hydro-
`carbon-based lubricant according to the present invention
`can include other additives or materials of the type used in
`refrigerant compositions to enhance their performance in
`refrigeration systems. For example,
`the composition can
`include also extreme pressure and antiwear additives, oxi-
`
`dation and thermal stability improvers, corrosion inhibitors,
`viscosity index improvers, pour and floc point depressants,
`antifoaming agents, lubricants soluble in both the hydrocar-
`bon-based lubricant and non-chlorine-containing refriger-
`ant, viscosity adjusters and the like. Examples of such
`additives are disclosed in U.S. Pat. No. 5,254,280.
`
`[0024] Any suitable amounts of the refrigerant, surfactant
`and solubilizing agent can be used in the practice of the
`present invention. In general, the weight ratio of hydrocar-
`bon-based lubricant to non-chlorine-containing refrigerant 1s
`from about 0.1 to about 60 parts by weight of lubricant per
`100 parts by weight of refrigerant. Preferably, the amount of
`hydrocarbon-based lubricant
`to non-chlorine-containing
`refrigerant is from about 15 to about 50 parts by weight of
`lubricant per 100 parts by weight of refrigerant, and even
`more preferably, from about 15 to about 30 parts by weight
`of lubricant per 100 parts by weight of refrigerant.
`
`[0025] Furthermore the weight ratio of solubilizing agent
`to hydrocarbon-based lubricant is preferably from about 1 to
`about 50 parts by weight of solubilizing agent per 100 parts
`by weight of hydrocarbon-based lubricant, and more pretf-
`erably, from about 5 to about 30 parts by weight of solubi-
`lizing agent per 100 parts by weight of hydrocarbon-based
`lubricant, and even more preferably, from about 5 to about
`20 parts by weight of solubilizing agent per 100 parts by
`weight of hydrocarbon-based lubricant.
`
`to hydrocarbon-
`(0026) The weight ratio of surfactant
`based lubricant is preferably from about 0.01 to about 10
`parts by weight of surfactant per 100 parts by weight of
`hydrocarbon-based lubricant, and even more preferably,
`from about 1 to about 5 parts by weight of surfactant per 100
`parts by weight of hydrocarbon-based lubricant.
`
`(0027) Any of a wide range of methodsfor introducing the
`refrigerant composition to a refrigeration system comprising
`a hydrocarbon-based lubricant can used in the present inven-
`tion. For example, one method comprises attaching a refrig-
`erant container to the low-pressure side of a refrigeration
`system and turning on the refrigeration system compressor
`to pull the refrigerant into the system. In such embodiments,
`the refrigerant container may be placed on a scale suchthat
`the amount of refrigerant composition entering the system
`can monitored. When a desired amount of refrigerant com-
`position has been introduced into the system, charging is
`stopped. Alternatively, a wide range of charging tools,
`known to those of skill in the art, are commercially avail-
`able. Accordingly, in light of the above disclosure, those of
`skill in the art will be readily able to introduce non-chlorine
`compositions into refrigeration systems according to the
`present invention without undue experimentation.
`
`EXAMPLES
`
`In orderto illustrate, in a non-limiting manner, the
`[0028]
`present invention is described in connection with the fol-
`lowing examples of the present method and comparative
`example.
`
`Example 1
`
`[0029| The following example illustrates a use of the
`present method with an air-conditioning system.
`
`[0030] From an air-conditioning system containing chlo-
`rodifluoromethane (“R-22”) and mineral oil is removed the
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`R-22. A mixture of R-407C, polybutylene glycol and a
`surfactant 1s made. The mixture is added to the system. The
`system operates in satisfactory manner. The capacity of the
`system is within 10% of the capacity of a system comprising
`a mixture of R-407C and an ester lubricant. This indicates
`that there are no oil return problems.
`
`Example 2
`
`[0031] The following example illustrates a use of the
`present method with an air-conditioning system.
`
`[0032] From an air-conditioning system containing chlo-
`rodifluoromethane (“R-22”) and mineral oil is removed the
`R-22. Amixture of R-407C, PGB 503 (a polybutylene glycol
`having a molecular weight of 503 and a viscosity of 45
`centistokes at 37° C.), and Brij 97 (C,,H3.(O0CH,>CH,),OH,
`wherein n is about 2) is made. The mixture is added to the
`system. The system operates in satisfactory manner. The
`capacity of the system is within 10% of the capacity of a
`system comprising a mixture of R-407C and an ester lubri-
`cant. This indicates that there are no oil return problems.
`
`Example 3
`
`[0033] The following example illustrates a use of the
`present method with an air-conditioning system.
`
`[0034] From an air-conditioning system containing chlo-
`rodifluoromethane (“R-22”) and mineral oil is removed the
`R-22. A mixture of R-407C, Mobil EAL 22 (an ester
`lubricant having a viscosity of 32 centistokes at 37° C.), and
`and Brij 97 (C,.H;;(O0CH.CH,),OH, wherein n is about 2)
`is made. The mixture is added to the system. The system
`operates in satisfactory manner. The capacity of the system
`is within 10% of the capacity of a system comprising a
`mixture of R-407C andan ester lubricant. This indicatesthat
`there are no oil return problems.
`
`Example 4
`
`[0035] The following example illustrates a use of the
`present method with an air-conditioning system.
`
`[0036] From an air-conditioning system containing chlo-
`rodifluoromethane (“R-22”) and mineral oil is removed the
`R-22. A mixture of R-32 (22.5 wt. %), R-125 (24.5 wt. %),
`R-134a (51 wt. %), and R-600 (butane)
`(2 wt. %)
`is
`combined with Mobil EAL 22 and Bri 97 to form a
`refrigerant composition. The composition is added to the
`system. The system operates in satisfactory manner. The
`capacity of the system is within 10% of the capacity of a
`system comprising a mixture of R-407C and an ester lubri-
`cant. This indicates that there are no oil return problems.
`
`Comparative Example 1
`
`[0037| This comparative example illustrates the miscibil-
`ity of a cooling composition consisting of 10 wt % retrig-
`erant and 90 wt % mineraloil.
`
`[0038] A mixture of R-407C and Suniso 3G mineraloil
`was prepared in a glass tube at 25° C. When the concentra-
`tion of the R-407C was 10 wt. % and the concentration of
`the oil was 90 wt. %, the mixture had one phase. When the
`temperature was lowered to 0° C.,
`the mixture became
`cloudy and two liquid phases appeared. When the concen-
`tration of the refrigerant was increased to 14 wt. %, there
`were two liquid phases at 25° C.
`
`Comparative Example 2
`
`[0039| This comparative example illustrates the miscibil-
`ity of a cooling composition consisting of 90 wt % refrig-
`erant and 10 wt % mineraloil.
`
`(0040) A mixture comprising 90 wt. % of R-407C and 10
`wt. % Suniso 3G mineral oil was prepared in a glass tubeat
`25° C. The mixture had two phases.
`
`[0041] Having thus described a few particular embodi-
`ments of the invention, various alterations, modifications
`and improvements will readily occur to those skilled in the
`art. Such alterations, modifications and improvementsas are
`made obvious by this disclosure are intended to be part of
`this description though not expressly stated herein, and are
`intended to be within the spirit and scope of the invention.
`Accordingly, the foregoing description is by way of example
`only, and not limiting. The invention is limited only as
`defined in the following claims and equivalents thereto.
`
`Whatis claimed is:
`1. A method of recharging a refrigeration system of the
`type containing a chlorine-containingrefrigerant and a lubri-
`cant, comprising the steps of:
`
`(a) removing said chlorine-containing refrigerant from
`said refrigeration system while leaving a substantial
`portion of said lubricant in said system; and
`
`(b) introducing to said lubricant left in said system a
`composition comprising:
`
`(i) a non-chlorine-containing refrigerant;
`
`(ii) a surfactant; and
`
`(iu) a solubilizing agent.
`2. The method of claim 1 wherein said non-chlorine-
`containing refrigerant comprises an HEC.
`3. The method of claim 1 wherein said non-chlorine-
`containing refrigerant is a mixture of two or more HFC
`compounds.
`4. The method of claim 1 wherein said non-chlorine-
`containing refrigerant is R-407C.
`5. The method of claim 1 wherein said surfactant
`enhances the solubility of said non-chlorine-containing
`refrigerant in said hydrocarbon-based lubricant by at least
`about 2 weight %.
`6. The method of claim 1 wherein said surfactant
`enhances the solubility of said non-chlorine-containing
`refrigerant in said hydrocarbon-based lubricant by at least
`about 5 weight %.
`7. The method of claim 1 wherein said surfactant
`enhancesthe solubility of said hydrocarbon-based lubricant
`in said non-chlorine-containing refrigerant by at least about
`2 weight %.
`8. The method of claim 1 wherein said surfactant com-
`prises a polyoxyethylene-type nonionic surfactant.
`9. The method of claim 4 wherein said surfactant com-
`prises a polyoxyethylene-type nonionic surfactant.
`10. The method of claim 9 wherein said surfactant is a
`polyoxyethylene alkyl ether.
`11. The method of claim 1 wherein said surfactant is
`soluble in said solubilizing agent.
`12. The method of claim 1 wherein said solubilizing agent
`comprises a polyalkylene glycol.
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`US 2002/0046568 Al
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`Apr. 25, 2002
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`13. The method of claim 12 wherein said polyalkylene
`glycol comprises a polybutylene glycol compound.
`14. The method of claim 13 wherein said polybutylene
`elycol compound has a viscosity of between about 1 and 20
`centistokes at 100° C.
`15. The method of claim 14 wherein said polybutylene
`elycol compoundhas a viscosity of between about 1 and 10
`centistokes at 100° C.
`16. The method of claim 15 wherein said polybutylene
`elycol compound has a viscosity of between about 1 and 5
`centistokes at 100° C.
`17. The method of claim 4 wherein said solubilizing agent
`is an ester or polyvinyl ether.
`18. Amethod of charging a refrigeration system compris-
`ing the steps of:
`
`(a) providing a refrigeration system comprising a chamber
`having a hydrocarbon-based lubricant and substantially
`no chlorofluorocarbon refrigerant; and
`
`(b) introducing to said chamber a composition compris-
`ing:
`
`(i) a non-chlorine-containing refrigerant;
`
`(ii) a surfactant; and
`
`(iu) a polyalkylene glycol lubricant.
`19. The method of claim 18 wherein said non-chlorine-
`containing refrigerant comprises an HFC.
`20. The method of claim 19 wherein said non-chlorine-
`containing refrigerant is R-407C.
`21. The method of claim 19 wherein said surfactant
`comprises a polyoxyethylene-type nonionic surfactant.
`22. The method of claim 19 wherein said solubilizing
`agent comprises a polyalkylene glycol.
`23. The method of claim 22 wherein said polyalkylene
`glycol comprises a polybutylene glycol compound.
`
`*
`
`a
`
`*
`
`*
`
`K
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