United States Patent (19)
`Weber, III
`
`III III IIII
`USOO5492643A
`5,492,643
`Patent Number:
`Feb. 20, 1996
`Date of Patent:
`
`11)
`45
`
`54 ENVIRONMENTALLY SAFER
`REPLACEMENT REFRGERANT FOR
`FREON 12-BASED REFRGERATION
`SYSTEMS
`
`75) Inventor: Harrison M. Weber, III, Baton Rouge,
`La.
`
`73 Assignee: Kenneth B. Ruello, Jr., New Orleans,
`La.
`
`21 Appl. No.: 233,444
`22 Filed:
`Apr. 26, 1994
`(51) Int. Cl. ......................... C09K 5/04; C1OM 101/00
`52 U.S. Cl. ..............
`... 252/68; 252/67; 62/114
`58 Field of Search ........................... 252/67, 68; 62/114
`
`(56)
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,810,403 3/1989 Bivens et al. ............................. 252A67
`4,971,712 11/1990 Gorski et al. ............................. 252A68
`4,983,312
`1/1991 Tamura et al............................. 252/67
`5,145,594 9/1992 Anton et al. .............................. 252/68
`5,254,280 10/1993 Thomas et al. ........................... 252/68
`5,384,057
`1/1995 Wilczek .................................... 252/68
`
`
`
`FOREIGN PATENT DOCUMENTS
`430131 6/1991 European Pat. Off..
`91/14751 10/1991 WIPO.
`OTHER PUBLICATIONS
`Heinrich et al., "Metamorphosis of refrigerant filling',
`Chemical Abstracts, 119, 52251, 1992.
`Primary Examiner-Christine Skane
`Attorney, Agent, or Firm-Pravel, Hewitt, Kimball &
`Krieger
`57)
`ABSTRACT
`An apparatus and method and refrigerant wherein ozone
`layer-damaging dichlorodifluoromethane is substituted with
`a mix of less environmentally damaging refrigerants chlo
`rodifluoroethane and tetrafluoroethane in dichlorodifluo
`romethane-based air-cooling systems. While less environ
`mentally damaging than dichlorodifluoromethane, the
`substitute refrigeranthas a temperature-pressure relationship
`similar to that of dichlorodifluoromethane, making the sub
`stitute refrigerant suitable for use with dichlorodifluo
`romethane-based air-cooling systems. The refrigerant
`includes a lubricant which is compatible with dichlorodif
`luoromethane, chlorodifluoroethane and tetrafluoroethane.
`4 Claims, No Drawings
`
`Dynatemp EX1005
`Page 1 of 5
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`

`

`5,492,643
`
`1
`ENVIRONMENTALLY SAFER
`REPLACEMENT REFRGERANT FOR
`FREON 12-BASED REFRGERATION
`SYSTEMS
`
`BACKGROUND OF THE INVENTION
`
`2
`These Freon 126) recharger kits typically consisted of a 12
`ounce aerosol can containing Freon 1209. The cans were
`fitted with an aerosol dispensing outlet that was compatible
`with a commercially available refrigeration manifold. In
`order to recharge an air-conditioning system, a customer
`needed to only fit the can to the manifold and discharge, or
`"drop in” the can's refrigerant charge directly into the air
`conditioning system, thus eliminating the need to bleed the
`system of existing Freon 12(E) before recharging.
`Following Congress's ban on the retail sale of Freon 12(6)
`recharger kits, millions of automobile owners with Freon
`126)-based air-conditioning units were left with no choice
`other than to seek expensive professional service to recharge
`their automotive air-conditioning units.
`Also in response to Congress's ban on the use of Freon
`12(8) in automobile air-conditioning, professional automo
`tive service dealers began to retrofit existing Freon 12(E)-
`based air-conditioning units into new, non-freon 12 refrig
`erant-compatible units.
`The refrigerant authorized by the Environmental Protec
`tion Agency (EPA) to replace Freon 12(R) in automobile air
`conditioners is tetrafluoroethane (hereinafter referred to as
`“134a'). Unfortunately, 134a has a markedly different tem
`perature-pressure relationship at high operating tempera
`tures than does Freon 12(E).
`Because of this difference in the temperature-pressure
`relationship of Freon 12(E) and replacement 134a, existing
`Freon 12(E)-based systems cannot simply be bled of Freon
`12(E) and refilled with 134a. Were Freon 12(8) to be replaced
`by 134a in a non-retrofitted Freon 12(E)-based air-condition
`ing unit, the unit could not be operated at high temperatures
`because the significantly higher pressure of 134a over Freon
`126) would damage the unit. Hence, non-retrofitted, Freon
`126)-based units that are simply refilled with replacement
`134a are inoperative at high operating temperatures; thus,
`inoperative at precisely the time that air-conditioning is most
`desired.
`Further, simply mixing 134a with existing Freon 12(E) in
`order to replenish, or "top off the level of coolant is not
`feasible. When 134a is mixed with Freon 12(E), the mixture
`takes on the pressure characteristics of a higher pressure
`azeotrope, as opposed to Freon 12(R). The temperature
`pressure profile of 134a becomes markedly different from
`that of Freon 120) attemperatures within the high end of the
`normal refrigerant operating temperature range. Hence,
`replenishing lost Freon 126) with 134ain a Freon 120-based
`air-conditioning system would lead to the same problems as
`the use of pure 134a in a non-retrofitted Freon 120-based
`system: Damage to the system caused by 134a's high
`pressure at high operating temperatures.
`In addition, 134a is insoluble with the lubricant used in
`existing, non-retrofit Freon 120)-based systems. Thus, mix
`ing 134a with Freon 12(E) in a non-retrofit Freon 12(E)-based
`unit leads to loss of lubrication and subsequent damage to
`the system.
`Hence, in the absence of Freon 126) recharger kits,
`owners of automobiles with Freon 12(E)-based air condition
`ers face but one choice when the level of their air-condi
`tioning coolant was low: Professional service to-at a
`significant cost- to remove the existing Freon 120), and
`retrofit the system to be compatible with 134a gas.
`Prior to January, 1994, owners of the millions of auto
`mobiles with Freon 12(E)-based air-conditioning units had a
`choice of whether to merely top of the level of air-condi
`tioning coolant with an inexpensive do-it-yourself Freon
`126) recharger kit or to undergo an expensive retro-fitting
`
`10
`
`15
`
`20
`
`25
`
`30
`
`1. Field of the Invention
`The present invention relates to the gradual replacement
`of ozone-damaging Freon 1208) refrigerant with a refrigerant
`that is less damaging to the ozone layer in systems designed
`to use Freon 120). More particularly the present invention
`relates to an improved refrigerant composition, method and
`apparatus for refrigeration wherein two non-Freon 12 refrig
`erants are mixed in a defined ratio such that the temperature
`pressure relationship of the mix approximates that of ozone
`damaging Freon 12(E), especially at high operating
`temperatures. The mixture is compatible with Freon 120R) so
`that it can be added to supplement and gradually replace
`ozone-damaging Freon 120). A further particularity of the
`instant invention relates to an improved method and appa
`ratus for refrigeration wherein refrigerant mixture is mixed
`with a soluble lubricating oil to provide lubrication to the
`apparatus. The lubricant is soluble in both the mixture of the
`invention and Freon 12(6) refrigerant.
`2. General Background
`Until recently, R-12 or dichlorodifluoromethane (herein
`after called "Freon 12(E)'); While Freon 12(E) is a trade name
`of E. I. du Pont de Nemours & Co. Inc. for dicholordifluo
`romethane, hereinafter "Freon 120” is used in this specifi
`cation to denote dicholorodifluoromethane, regardless of the
`source) was the major, if not sole refrigerant, used in
`automobile air-conditioners, refrigerators, freezers and win
`dow air-conditioning units.
`35
`Recently, however, Freon 12(E) has come under attack
`both nationally and internationally as an ozone layer-dam
`aging chemical. In recent years, both the national and
`international scientific communities have linked Freon 12(E)
`with damage to the earth's protective ozone layer. Automo
`40
`bile air-conditioners, refrigerator/freezers and window air
`conditioning units are believed to be a significant global
`source of ozone-damaging Freon 12(E).
`In response to both scientific concern and a national and
`global outcry over the use of Freon 120R) in air-conditioning,
`the United States Congress has acted to first reduce and then
`ban the use of Freon 126 in air-conditioning units.
`One of the first areas in which the use of Freon 12(E) is to
`be phased out is in automobile air-conditioning. As a first
`step toward phasing out the use of Freon 120) in automobile
`air-conditioning units, Congress is phasing out the use of
`Freon 12(R) in new automobiles and has banned the sale of
`Freon 12(E) in small retail quantities for the do-it-yourself
`air-conditioner recharger market.
`However, at the time of this application, the vast majority
`of automobiles in use in the United States contain Freon
`12(E)-based air-conditioning units, and approximately 40%
`of new automobiles continue to contain Freon 12(E)-based air
`conditioners.
`Prior to banning the retail sale of small quantities of Freon
`1208, owners of automobiles with Freon 120E)-based air
`conditioning units were able to recharge, or "top-off” the
`level of coolant in their automobile air-conditioners without
`the need for expensive professional service. Millions of 65
`units of Freon 120 recharging units were sold in the United
`States prior to being banned in January, 1994.
`
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`50
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`55
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`60
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`5,492,643
`
`3
`process. However, at the time of this application, owners of
`automobiles with Freon 12(E)-based air-conditioners no
`longer have this choice. They must undergo expensive
`professional maintenance, or discontinue the use and enjoy
`ment their automobile air-conditioners.
`
`4
`conditioning units, it is not so limited in its use. Indeed, the
`refrigerant may be utilized as a substitute or replacement for
`Freon 12(E) in virtually any application, thereby eliminating
`the use of ozone layer-damaging Freon 12(E).
`In further specifics, the invention provides a canister
`containing a mixture of tetrafluoroethane and chlorodifluo
`rethane that may be fitted with an outlet manifold that is
`compatible with a Freon 12(8) recharging manifold that is
`typically used to recharge an apparatus with the latter
`refrigerant. Refrigerant may then be allowed to flow from
`the container through the manifold and into the apparatus to
`replace Freon 12(8) refrigerant that has been lost from the
`refrigeration system or to completely fill the apparatus.
`DETALED DESCRIPTION OF THE
`PREFERRED EMBODIMENT
`The present invention provides a mixture of non-Freon 12
`refrigerants that are less damaging to the Earth's ozone layer
`and that are approved by the U.S. Environmental Protection
`Agency for use in air-conditioners. The invention mixture is
`compatible with Freon 12(E) and can be used to fill or "top
`off existing Freon 12(E)-based refrigeration systems. It is
`expected that the present invention will gradually replace
`Freon 12(R) in Freon 12(R)-based air-cooling systems, without
`the need to remove Freon 12(E) from existing systems and
`without the need to retrofit existing Freon 12(E)-based sys
`tems for non-Freon 12 replacement refrigerants.
`Specifically, the preferred embodiment includes a mixture
`of 142b and 134a refrigerants and a compatible lubricant
`such as ROYCO(E) 783C or 783D, provided under pressure
`in an aerosol can equipped with an outlet compatible with
`existing Freon 12(E) recharger kit manifolds, so that the can's
`refrigerant and lubricant mixture can be added on top of
`existing Freon 12(E) coolant in Freon 12(E)-based coolant
`systems. Also, the invention provides the possibility of using
`new refrigerant systems, originally designed for "Freon
`12(R), by supplying an EPA-approved refrigerant so that
`retrofitting for 134a use is not required.
`In the most preferred embodiment, the invention provides
`an aerosol can like the standard 12 ounce can formerly used
`for containing "Freon 12(E),” but containing about 80% by
`weight 134a and about 20% by weight 142b. The can also
`contains the preferred lubricant, ROYCO(R)783C or 783D in
`solution with the coolant mixture at a percent by weight of
`between 0.5% and 2%.
`Existing Freon 12(E)-based air-conditioning systems use a
`small amount of a vegetable or hydrocarbon oil to lubricate
`the compressor. This oil has a very low vapor pressure, and
`is not soluble with either pure 134a or the 80/20% wit/wt
`mixture of 134a and 142b. Hence, adding 134a to replace
`Freon 12(E) in existing Freon 12(E)-based air-conditioning
`systems leads to compressor breakdown from lack of suf
`ficient lubrication. The invention provides lubricants that are
`compatible with the invention mixture of 134a and 142b,
`and with "Freon 1208),” and that are suitable for lubricating
`refrigerant compressors and other air-conditioner compo
`ment parts. The most preferred ROYCO(E) 783C or 783D
`lubricants, on the other hand, are soluble in a 134a/142b
`mixture. This solubility allows the replacement refrigerant
`blend to lubricate the air-conditioning system, preventing
`damage to the compressor and component parts of the
`System.
`
`65
`
`EXAMPLE 1
`Table 1 summarizes the results of solubility tests of a 2%
`by weight solution of either ROYCO(E) 783C or 783D
`
`10
`
`15
`
`20
`
`25
`
`35
`
`40
`
`45
`
`50
`
`55
`
`30
`
`SUMMARY OF THE PRESENT INVENTION
`The invention provides a method and apparatus that are
`environmentally sound alternatives to the use of Freon 126)
`as a refrigerant. More particularly, the invention provides a
`mixture of at least two refrigerants that are miscible with
`each other, and compatible with Freon 1208) while at the
`same time possessing a temperature-pressure profile that
`approximates that of Freon 1208) over the operating range of
`ambient temperatures usually encountered by air condition
`ing units or other apparatus utilizing Freon 12(E) as a
`refrigerant. The invention also provides a lubricant, that is
`compatible with both the environmentally sound refrigerant
`of the invention and also compatible with Freon 12(E), so that
`mixtures of the refrigerant according to the invention and
`Freon 12(R) may be utilized with this lubricant in the refrig
`eration systems without deleterious effect upon moving parts
`of the refrigerating apparatus that require lubrication from
`the refrigerant.
`More particularly, the invention provides a mixture of
`chlorodifluroethane and difluoroethane in specific propor
`tions that provide a temperature-pressure relationship that
`approximates that of Freon 12(E) over the range of ambient
`temperature operating conditions in which Freon 12(E) is a
`useful refrigerant. More specifically, the refrigerant accord
`ing to the invention comprises from about 15 to about 40
`weight percent chlorodifluoroethane and from about 85 to
`about 60 percent tetrafluoroethane, based upon the total
`weight of chlorodifluoroethane and tetrafluoroethane. Pref
`erably, the refrigerant includes from about 15 to about 20
`weight percent chlorodifluoroethane and from about 85 to
`about 80 weight percent tetrafluoroethane. Most preferably,
`the refrigerant includes about 20 weight percent chlorodif
`luoroethane and about 80 weight percent tetrafluoroethane.
`In addition, the refrigerant according to the invention also
`includes from about 0.5 to about 2 weight percent (based on
`the weight of chlorodifluroethane and tetrafluoroethane) of a
`lubricating oil that is soluble in dichlorodifluoromethane,
`chlorodifluoroethane, and tetrafluoroethane. Preferably, the
`lubricant is selected from those lubricants sold by Royal
`Lubricants Company under the trademarks ROYCO(E) 783C
`or ROYCO(E) 783D. It should be understood, however, that
`other lubricating oils may also be used, as long as they are
`compatible with chlorodifluoroethane, tetrafluoroethane,
`and Freon 12(R).
`While it is intended that the substitute refrigerant accord
`ing to the invention may be utilized to replace lost Freon
`12(8) that has escaped from apparatus, the substitute refrig
`erant of the invention may also be utilized to completely
`refill apparatus that have been designed for use with Freon
`12(E), since the refrigerant has a temperature-pressure profile
`that closely approximates that of Freon 12(8). Thus, when the
`refrigerant is used as a complete replacement for Freon 12(E),
`60
`it is no longer necessary that the lubricant should be com
`patible with dichlorodifluoromethane but only that it should
`be compatible with tetrafluoroethane and chlorodifluoroet
`hane.
`Further, whereas the substitute refrigerant of the invention
`is less damaging to the ozone layer than Freon 12(R) is useful
`in air conditioning units, and in particular automobile air
`
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`5
`lubricant (both gave identical results) in an 80/20% by
`weight mixture of 134a and 142b refrigerants. Either
`ROYCO(E)783CORROYCO(E)783D (available from Royal
`Lubricants Co. as MIL-H-6083EAM.1, NSN:9150-00-935
`9808), containing reddye, was added to a clear Fisher-Porter
`pressure burette and a mixture of 134a/142b in an 80/20 ratio
`by weight was introduced under pressure to maintain the
`liquid state.
`
`Full Burette
`% Fu Burette
`A Full Bureite
`A Fu Burette
`Almost Empty Burette
`
`TABLE 1.
`clear red, no separation
`clear red, no separation
`clear red, no separation
`clear red, no separation
`clear red, no separation
`
`Note: The color of the fluid remained the same as the burette was emptied.
`The expelled gas deposited the oil onto a test panel, as shown by the red color.
`
`EXAMPLE 2
`In the invention, 134a and 142b are mixed at set ratios
`such that the temperature-pressure profile of the mixture is
`similar to that of Freon 12(E), over the normal operating
`range of air-conditioners. Table 2 summarizes the results of
`tests of the temperature-pressure profiles of various mixes of
`134a and 142b over the range of normal air-conditioner
`working temperatures, from 65° F to 100 F.
`For Table 2, different percentages of 134a and 142bp-by
`weight-were mixed and sealed in a container using a high
`pressure burette. The container was then submerged in a
`water bath for 5 minutes at each temperature. All pressure
`readings were taken three times and an average taken as the
`reported reading.
`
`TABLE 2
`
`PRESSURE IN PSG OF INVENTION MIXTUREAT
`TEMPERATURE IN FAS COMPARED TO
`FREON 12(3) AND 134a
`
`10
`
`15
`
`20
`
`25
`
`35
`
`MXTURE OF
`
`142b-134a wt %
`
`5%-95%
`10%-90%
`15%-85%
`20%-80%
`100%. 134a
`100% Freon 2 (R)
`
`TEMPERATURE (F)
`
`40
`
`65
`
`68
`66
`66
`65
`76
`
`70
`
`74
`74
`7.
`70
`79
`70
`
`80
`
`86
`83
`82
`80
`90
`84
`
`90
`
`95
`93
`92
`89
`100
`100
`
`100
`
`128
`124
`123
`120
`134
`117
`
`45
`
`As can be seen in Table 2, a range of about 15% to about
`20% by weight of 142b and about 80% to about 85% by
`weight of 134a is preferred. The most preferred ratio is about
`20% by weight 142b and about 80% by weight 134a. This
`is the ratio of 142b to 134a where the mixture of the
`invention shows the greatest similarity to “Freon 12(6),”
`especially at the higher operating temperatures. Signifi
`cantly, at this higher temperature range the pressure of 134a
`in pure formis well above that of Freon 1208) so that it would
`pose a hazard if used in equipment designed for using Freon
`12(R).
`In the most preferred embodiment of the composition, the
`most preferred ratios of 134a and 142b are mixed with a
`preferred range of from 0.5% to 2% by weight of either
`ROYCOGR 783C or 783D lubricant.
`The apparatus and method of the preferred embodiment
`encompasses the use of a mixture of 134a and 142b at
`preferred ranges, as discussed above, with either ROYCO(E)
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`5,492,643
`
`6
`783C or 783D lubricant at preferred ranges, as discussed
`above (0.5-2% by weight) in the operation of an air
`conditioning system, wherein the coolant-oil mixture gradu
`ally replaces Freon 1269 in a Freon 12(E)-based refrigeration
`system.
`The method and apparatus in the preferred embodiment
`further details providing the above described mix of 142b/
`134a and 783C/D in high strength, 2q aerosol containers.
`Where the containers are pressure sealed and fitted with an
`outlet compatible for existing Freon 12-type refrigeration
`regeneration manifolds.
`
`EXAMPLE 3
`A mixture of 19% by weight 142b, 79% by weight 134a
`and 2% by weight ROYCO(E) 783C was added to the cooling
`system of a 1987 Ford Taurus. This system was a Freon
`1209-based cooling system that contained Freon 12(E), but
`had a slow leak. As a result, the system had a low charge of
`Freon 120), requiring "topping off.”
`When this system was fully charged with Freon 120 it
`normally ran a coolant pressure at the vacuum side of the
`system of 40 psig at 85° F ambient temperature. Prior to
`applying the mixture according to the invention, the system
`showed 25 psig at the vacuum side of the system at 85 F.
`ambient temperature. Further, prior to the addition of the
`mixture, the accumulator did not show continuous conden
`sation and air that passed over the evaporator was not
`chilled.
`Approximately 12 ounces of the mixture was added to the
`system. Following this addition, the coolant pressure
`increased to 42 psig at the vacuum side of the system at 85
`F. ambient temperature. Further, the accumulator began to
`show continuous condensation and the evaporation fan
`began to blow cold air, indicating cooling of air as it passed
`over the evaporator coil.
`A similar charge of the mixture was added two more times
`over an eight month period. During this time the automobile
`was routinely operated in warm temperatures with the
`air-conditioning in use. Throughout this test period, the
`air-conditioning system maintained pressure, continuous
`condensation and blew cold air. During the length of the
`eight month test period, the temperature of the air exiting the
`cold air vent was acceptably cool and averaged 43 F.
`Further, it was noted that the system ran more smoothly
`and the compressor showed less vibration during the test
`period, as the mixture of the invention was added. It is
`theorized that the lubricating oil, being soluble in the refrig
`erant gasses, was better able to lubricate the rotating wobble
`plate and reciprocating parts than the existing Freon 126)
`lubricant. Engine efficiency and gasoline millage did not
`vary.
`As used herein, "tetrafluoroethane' refers to refrigerant
`134a (1,1,1,2-tetrafluoroethane).
`ROYCO(E) 783c and ROYCO(E) 783D are trademarks of
`Royal Lubricants Company Inc., E. Handover, N.J., for
`lubricants having the following composition:
`60-80% hydrotreated light naphthenic distillate,
`10-20% acrylic polymer in severely hyrotreated mineral
`oil,
`5-15% solvent refined light naphthenic distillate petro
`leum,
`2-7% additive containing barium dinonylnaphthalene
`Sulfonate,
`<0.5% butylated triphenyl phosphate, and
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`5,492,643
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`<2% minor additive.
`It should be understood that variations and modifications
`may be made of the invention herein taught, and that those
`are within the scope and spirit of the invention as taught
`above and claimed herebelow.
`What is claimed as invention is:
`1. A refrigerant consisting of:
`about 15% to about 40% by weight chlorodifluoroethane;
`about 60% to about 85% by weight tetrafluoroethane; and
`about 0.5% to about 2% by weight of the refrigerant of a
`lubricating oil that is soluble in dichlorodifluo
`romethane, chlorodifluoroethane and tetrafluoroethane,
`the lubricating oil having the following composition:
`60-80% hydrotreated light naphthenic distillate,
`10-20% acrylic polymer in severely hyrotreated mineral
`oil,
`5-15% solvent refined light naphthenic distillate petro
`leum,
`
`O
`
`15
`
`8
`2-7% barium dinonylnaphthalenesulfonate and
`<0.5% butylated triphenyl phosphate.
`2. A refrigerant according to claim 1 wherein said chlo
`rodifluoroethane is present in an amount of about 20% by
`weight and said tetrafluoroethane is present in an amount of
`about 80% by weight.
`3. A refrigerant according to claim 1 wherein said chlo
`rodifluoroethane is present in an amount of about 15% to
`about 20% by weight and said tetrafluoroethane is present in
`an amount of about 80% to about 85% by weight.
`4. A refrigerant according to claim 1 wherein said chlo
`rodifluoroethane is present in an amount of about 40% by
`weight and said tetrafluoroethane is present in an amount of
`about 60% by weight.
`
`ck
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`k
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