U.S. patent application number 10/226384 was filed with the patent office on 2002-12-19 for apparatus, methods and compositions for placing additive fluids into a refrigerant circuit.
Invention is credited to Ferris, James E., Quest, William J.
Application Number | 20020189265 10/226384 |
Document ID | / |
Family ID | 27122421 |
Filed Date | 2002-12-19 |
United States Patent
Application |
20020189265 |
Kind Code |
A1 |
Ferris, James E. ; et
al. |
December 19, 2002 |
Apparatus, methods and compositions for placing additive fluids
into a refrigerant circuit
Abstract
A supply canister is partially filled with a refrigerant circuit
additive fluid which is partially evacuated, said refrigerant
circuit additive fluid is comprised of a combination of a binding
azeotrope of methanol and cyclohexanone with a drying agent, a
metal sealant and a rubber rejuvinating compound in a single
container. Additive fluids from the canister may be placed into the
refrigerant circuit of an air conditioning system by (1) connecting
the canister to the circuit after it has been emptied and vacuum
pressure created therein, (2) connecting the canister to the
refrigerant circuit suction line during system operation, or (3)
connecting the canister to the suction line with the system off, to
thereby force refrigerant from the circuit into the canister, and
then starting the system to cause the vacuum pressure in the
suction line to draw the contents of the canister into the
refrigerant circuit.
Inventors: |
Ferris, James E.;
(Richardson, TX) ; Quest, William J; (Dallas,
TX) |
Correspondence
Address: |
Henry Croskell
6817 Cliffbrook
Dallas
TX
75254
US
|
Family ID: |
27122421 |
Appl. No.: |
10/226384 |
Filed: |
August 23, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10226384 |
Aug 23, 2002 |
|
|
|
09965749 |
Sep 28, 2001 |
|
|
|
6438970 |
|
|
|
|
10226384 |
Aug 23, 2002 |
|
|
|
09802178 |
Mar 8, 2001 |
|
|
|
Current U.S.
Class: |
62/77 ;
62/292 |
Current CPC
Class: |
F25B 43/003 20130101;
F25B 2345/001 20130101; C09K 3/12 20130101; F25B 45/00
20130101 |
Class at
Publication: |
62/77 ;
62/292 |
International
Class: |
F25B 045/00 |
Claims
What is claimed is:
1. An additive fluid for refrigerant circuits are selected from at
least two compounds of the group consisting of a binding azeotrope,
a drying agent, a moisture-activated metal sealant and a rubber
rejuvinating compound; the at least two compounds are contained in
one fluid additive.
2. An additive fluid according to claim 1 wherein the azeotrope is
comprised of methanol and cyclohexanone.
3. An additive fluid according to claim 1 wherein the metal
sealants are comprised of organo-silane compounds.
4. An additive fluid according to claim 1 wherein the azeotrope is
comprised of about 98% by volume of methanol and about 2% by volume
cyclohexanone.
5. An additive fluid according to claim 1 wherein the drying agent
is comprised of a dehydrated alcohol having one to three carbon
atoms per molecule.
6. The drying agent according to claim 1 wherein dehydrated
dihydric, trihydric and polyhydric alcohols scavenge for water and
are capable of forming azeotrope or azeotrope-like mixtures.
7. An additive fluid for refrigerant circuits comprising
compositions consisting of an azeotrope, drying agent, a
moisture-activated metal sealant, and a rubber rejuvinating
compound, selected from the group consisting of; (1) metal sealants
comprising 10% by volume of a water scavenger, 60% by volume of a
metal bonding compound and 30% by volume of a cross-linking
compound all of which are organo-silane compounds; (2) an azeotrope
comprising about 50% by volume methanol and about 1% by volume
cyclohexanone, mixed with about 2% by volume methylene chloride, a
softener and about 47% by volume of PAG oil; (3) a drying agent
comprised of a dehydrated alcohol having one to three carbon atoms
per molecule; (4) about an equal amount of all the other components
of R134a carrier; and (5) the compositions are contained in the
same fluid.
8. A method of placing an additive fluid into a refrigerant
circuit, said method comprising the steps of: providing a vessel
having a partially evacuated interior partially filled with an
additive fluid, said additive fluid comprising a combination of a
binding azeotrope, a drying agent, a moisture-activated metal
sealant and a rubber rejuvinating compound; and communicating the
refrigerant circuit with said partially evacuated interior of said
vessel.
9. The method of claim 8 wherein said providing step is performed
using a vessel partially filled with an additive fluid, comprising
a combination of a binding azeotrope, a drying agent, a
moisture-activated metal sealant and a rubber rejuvinating
compound.
10. The method of claim 8 wherein said providing step is performed
using a vessel having an interior vacuum pressure in the range of
from about 12" Hg to about 15" Hg.
11. The method of claim 8 wherein said communicating step is
performed by operatively interconnecting a refrigerant recharge
hose assembly between said vessel and said refrigerant circuit.
12. The method of claim 8 wherein: said refrigerant circuit
includes a suction line portion which, during operative flow of
refrigerant therethrough, has a vacuum pressure greater than the
vacuum pressure within said vessel, and said communicating step
includes the step of communicating said partially evacuated
interior of said vessel with the interior of said suction line
portion, during operative flow of refrigerant therethrough, in a
manner flowing said compound comprising an azeotrope, a drying
agent, a moisture-activated metal sealant and a rubber rejuvinating
compound into said suction line portion from a common
container.
13. A method of placing an additive fluid comprising a combination
of a binding azeotrope, a drying agent, a moisture-activated metal
sealant and a rubber rejuvinating compound, into a refrigerant
circuit, said method comprising the steps of: providing a vessel
having a partially evacuated interior partially filled with the
additive fluid and being substantially devoid of refrigerant, and
communicating the interior of said refrigerant with said partially
evacuated interior of said vessel.
14. The method according to claim 13 wherein: said refrigerant
circuit has a suction line portion which, during operative flow of
refrigerant flow therethrough, has a vacuum pressure greater than
the vacuum pressure within said vessel, and said communicating step
is performed by communicating the interior of said suction line
portion with said partially evacuated interior of said vessel
during operative flow of refrigerant through said suction line
portion.
15. The method according to claim 13 wherein: said refrigerant
circuit has a suction line portion which, during operative flow of
refrigerant therethrough, has a vacuum pressure greater than the
vacuum pressure within said vessel, said suction line portion, in
the absence of an operative flow of refrigerant flow therethrough,
has a positive pressure, said communicating step is performed by
communicating said partially evacuated interior of said vessel with
the interior of said suction line portion, during an absence of
operative refrigerant flow therethrough, to thereby force
refrigerant from said refrigerant circuit into said vessel, and
said method further comprises the step, performed after said
communicating step, of creating an operative flow of refrigerant
through said suction line portion to thereby draw refrigerant and
additive liquid into said refrigerant circuit from within said
vessel.
Description
[0001] This application is a continuation-in-part application of
Ser. No. 09/802,178 filed on Mar. 8, 2001, still pending.
FIELD OF THE INVENTION
[0002] The present invention relates to methods of dehydrating,
passivating, sealing of refrigeration systems and a method for
delivering combination of a binding azeotrope of methanol and
cyclohexanone, a drying agent, a moisture activated metal treatment
and rubber rejuvinating compound into a single container.
[0003] The present invention generally relates to the maintenance
of air conditioning or refrigeration systems and, in a preferred
embodiment thereof, more particularly relates to apparatus and
methods for placing an additive fluid in to the refrigerant circuit
of an air conditioning system.
[0004] In the typical air conditioning or refrigeration system it
is often necessary to place an additive fluid (normally a liquid)
into the refrigerant circuit portion of the system to maintain the
performance of the system at a satisfactory level. Examples of
additive fluids placed in refrigerant circuits include compressor
oil, stop-leak liquid, acid neutralizers, drying agents, and
ultraviolet colored leak-finder liquid.
[0005] Additive fluids of these and other types are conventionally
placed in refrigerant circuits by one of four methods--namely, (1)
the refrigerant circuits by one of four methods (2) the additive
fluid is placed in a container along with pressurized refrigerant
and is expelled with the pressurized refrigerant into the circuit;
(3) the additive fluid is placed in an in-line storage device, and
pressurized refrigerant is flowed through the storage device to
force the additive fluid into the circuit along with the
pressurized refrigerant; or (4) the additive fluid is injected into
the circuit using a mechanical piston to force the fluid into the
circuit.
[0006] These conventional techniques carry with them certain known
problems, limitations and disadvantages. For example, to simply
open the refrigerant circuit and pour the additive in can
undesirably cause release of refrigerant to the atmosphere, and can
also undesirably introduce contaminating air into the circuit.
Packaging an additive fluid in a container with pressurized
refrigerant to be forcibly injected into the circuit is also
undesirable due the expense of adding refrigerant to the container
as a propellant, the safety concerns inherent in a pressurized
container structure, and the need to match the refrigerant
propellant with the type of refrigerant within the circuit. Placing
the additive fluid in an in-line device requires that the
refrigerant forced through the device match the refrigerant in the
circuit to avoid contamination of the circuit. Injecting additive
fluid into a refrigerant circuit using a mechanical piston device
tends to be a somewhat cumbersome task requiring specialized
packaging and/or equipment.
[0007] Recently, severe restrictions by the U.S. Government has
been placed on use of chlorofluorocarbons (CFCs) due to
environmental problems which are as a result of the destruction of
stratospheric ozone. In addition, CFCs have been labeled as
environmentally unsafe in many countries worldwide. As a result,
proposed alternative substances which can be substituted for CFCs
in various applications have been and are being developed. Among
them are several new proposed hydrofluorocarbons (HFCs). A
substitution which is being used is HFC-R134a and related
compounds. These materials are being sold as a substitutes for CFC
as a refrigerant liquid for CFC as refrigeration fluids. These
replacement materials, while not ozone-depleting continue to
contribute in part to the greenhouse effect. Their use and escape
into the atmosphere is the subject of the EPA's Significant New
Alternatives Programs, which limits the use of fluroinated
compounds as alternatives for ozone-depleting chemicals.
[0008] The HFC replacement fluids are generally not as efficient as
CFCs and require new types of additives including fluids, sealants,
metal and rubber sealants as well as dehydrates and others. In
addition, redesign of compressive-evaporative refrigeration and
other systems using the HFCs has been necessary. The newer working
fluid refrigerants exhibit different soluabilities than CFCs, and
are not mixable with well known lubricants in CFC systems as well
as other additives. For example, in a modem system using these
compounds in cooperation with known lubricants causes hydrolysis of
the lubricating esters in a chemical reversion process. Further,
other chemical additives in the new environmental partially safe
system cause additional metal and rubber leakage which, again, can
bring on additional problems for the EPA and the environment.
[0009] Leaks allow refrigerants and other working fluids to escape
into the atmosphere, contaminating the environment and decreasing
the efficiency and cooling capacity of the unit. If large amounts
of cooling working fluids such as refrigerants escape, the system
may overheat and the service life of the unit will thereby be
shortened. Further, the unit may suffer mechanical failure from the
loss of the working fluid. In general, leaks in heating and cooling
systems also decrease the heat transfer efficiency of these
systems.
[0010] Water in all types of compressive-evaporative systems
decreases the system efficiency as a result of water's high heat of
vaporization and high heat capacity. The high heat of fusion of
water decreases the efficiency of a compressive-evaporative system
by giving off heat in evaporation cycles as the water freezes. The
resulting ice crystals can also block orifices in expansion valves
and cause such systems to malfunction.
[0011] A need continues to exist in the art for a method for
sealing leaks in refrigeration, air conditioning, heating and
ventilation and related systems and for the complete dehydration of
the systems. More importantly, there is a need that exist in the
prior art for the addition in a one-step application of a drying
agent, a moisture activated metal treatment and a rubber
rejuvinating compound in a single container in combination with a
binding azeotrope.
[0012] As can readily be seen from the foregoing, a need exists for
improved apparatus, methods for placing additive fluids and said
additive fluids into a refrigerant circuit. It is to this need that
the present invention is directed.
SUMMARY OF THE INVENTION
[0013] In carrying out principles of the present invention, in
accordance with a preferred embodiment thereof, a specially
designed vessel or canister is provided for use in placing an
additive fluid, representatively an additive liquid, into the
refrigerant circuit of an air conditioning or refrigeration system,
representatively an automotive air conditioning system. In a
preferred embodiment thereof, the vessel has an interior
communicatable with a suction line portion of the refrigerant
circuit, the vessel interior being partially filled with an
additive liquid, being partially evacuated to a vacuum pressure
less than that of the suction line portion during operation of the
air conditioning system, and being substantially devoid of
refrigerant.
[0014] According to a first method of utilizing the partially
evacuated vessel, the interior of the vessel is initially
communicated with the interior of the suction line portion during
operation of the air conditioning system, representatively using a
refrigerant recharge hose assembly, whereupon the greater vacuum
pressure in the suction line portion of the refrigerant circuit
draws the additive liquid into the suction line portion.
[0015] According to a second method of utilizing the partially
evacuated vessel, the refrigerant circuit is emptied and a vacuum
pressure is created therein which is greater than the vacuum
pressure within the vessel. The vessel is then communicated with
the interior of the refrigerant circuit, representatively using a
refrigerant recharge hose assembly, whereupon the greater vacuum
pressure within the emptied refrigerant circuit draws the additive
fluid into the refrigerant circuit.
[0016] Accordingly to a third method of utilizing the partially
evacuated vessel, the interior of the vessel is initially
communicated with the interior of the suction line portion,
representatively using a refrigerant recharge hose assembly, while
the air conditioning system is turned off and a positive pressure
exists in the interior of the suction line portion. The positive
pressure within the suction line portion forces refrigerant
therefrom into the vessel, thereby positively pressurizing its
interior. Next, the air conditioning system is turned on to create
a negative pressure within the suction line portion, thereby
drawing the refrigerant and additive liquid from the positively
pressurized canister interior into the suction line portion.
[0017] The provision and use of the specially designed partially
evacuated vessel provides a variety of advantages over conventional
pressurized canisters containing refrigerant and liquid additive.
For example, since there is no refrigerant in the vessel, the same
additive liquid-containing vessel can be used with a wide variety
of air conditioning or refrigeration systems that utilize different
type of refrigerants--the vessel does not have to be "matched" to a
particular type of refrigerant in a circuit in order to avoid
contamination thereof by a different type of refrigerant within the
vessel.
[0018] Moreover, since refrigerant is not packaged within the
vessel, the material cost of the partially filled vessel is
substantially reduced. Additionally, since there is no refrigerant
disposed within the as-manufactured vessel it cannot leak
refrigerant into the atmosphere, and the lack of pressurized
refrigerant within the as-manufactured vessel renders it safer to
ship and store.
[0019] The present invention also includes a method for dehydrating
refrigeration systems as well as a method for sealing metal and
rubber parts in a refrigerant system. This is accomplished by the
invention by using a azeotrope like material with at least 2 to 3
or more additives which are needed by modern air conditioning
systems. The invention also includes a method of dehydrating and
passivating the refrigerant systems having a fluid enclosure. The
method comprises adding a single additive mix maintained in a
binding azeotrope like material which allows the treatment of a
refrigerant system for many purposes including metal and rubber
sealing, dehydration and the like. In a one step application, for
example, in R134a systems. The composition containing multiple
additives and an azeotrope type mixture is allowed to react with
interior surfaces of the enclosure of the refrigerant system to
passivate, coat the surfaces as well as dehydrate the whole
refrigerant system thus completing a one application treatment for
the refrigerant system. An azeotrope or azeotrope mixture of
refrigerant additives for sealing both rubber and metal surfaces
within a refrigeration system which also dehydrates the system
simultaneously because of the dehydrator which is present and is
also included in the common container. The compositions include
various elements which combine and operate within the binding
azeotrope to deliver from a one container or one mix the desired
amount of each sealing, dehydrating and treatment of refrigerant
systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a schematic diagram of a representative air
conditioning system into the refrigerant circuit portion of which
an additive fluid is being placed using a specially designed,
partially evacuated additive fluid canister embodying principles of
the present invention.
[0021] FIG. 2 schematically illustrates the canister after its
additive fluid has been placed into the refrigerant circuit, with
FIGS. 1 and 2 together illustrating first and second methods of
placing an additive fluid into the refrigerant circuit; and
[0022] FIGS. 3 and 4 are schematic diagrams similar to those in
FIGS. 1 and 2 and together illustrate a third method of placing an
additive fluid and into a refrigerant circuit using the partially
evacuated additive fluid canister.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Schematically depicted in FIGS. 1 and 2 are first and second
methods of placing an additive fluid 10 in the refrigerant circuit
12 of an air conditioning or refrigeration system which is
representatively an automotive air conditioning system 14. The
additive fluid 10 is representatively an additive liquid such as,
for example, compressor oil, a stop-leak liquid, an ultraviolet
colored leak-finder liquid, an acid neutralizer, or a drying agent.
The air conditioning system 14 is representatively of the direct
expansion type and comprises the usual compressor 16, condenser 18,
expansion valve 20 and evaporator 22 connected as shown in the
refrigerant circuit 12. Compressor 16 is disposed between suction
and liquid line portions 12a, 12b of the circuit 12, with suction
line portion 12a having a low side pressure tap or service fitting
24 installed therein, and liquid line portion 12b having a high
side pressure tap or service fitting 26 installed therein. During
operation of the system 14, refrigerant is flowed through the
circuit 12 in the direction indicated by the circuit flow arrows in
FIG. 1.
[0024] According to a key feature of the present invention, a
specially designed vessel or canister 28 (see FIG. 1) is partially
filled with the additive liquid 10 and is partially evacuated to a
vacuum pressure suitable for the air conditioning system with which
the canister 28 is to be used (representatively in the range of
from about 12" to about 15" Hg vacuum for an automotive air
conditioning system refrigerant circuit) which is (1) less than the
vacuum pressure within the refrigerant circuit suction line portion
12a (typically in the range of from about 20" to about 30" Hg
vacuum for an automotive air conditioning system refrigerant
circuit) during operation of the air conditioning system
refrigerant circuit) during operation of the air conditioning
system 14 with refrigerant operatively flowing through the circuit
12, and (2) less than the positive pressure within the suction line
portion 12a (for example, about 78.4 psig when the ambient
temperature is 75 degrees F.) when the air conditioning system 14
is not operating, and refrigerant is not being flowed through the
circuit 12.
[0025] As schematically depicted in FIG. 1, the partially evacuated
interior 30 of the canister 28, as originally fabricated, contains
only the additive liquid 10 and is devoid of refrigerant. The
canister 28 thus differs in two primary regards from conventional
additive injection canisters--namely, (1) it does not contain
refrigerant, and (2) its interior is at a substantial negative
pressure as opposed to being highly pressurized. Canister 28 is of
a suitable metal material and has a hollow cylindrical body 32 with
a lower end 34 and an upper end 36 having an externally threaded
tubular projection 38 thereon, the projection 38 having a closed
upper end 40.
[0026] Representatively, the refrigerant circuit 12 schematically
depicted in FIG. 1 is filled with R134a refrigerant, with the
suction line service fitting 24 being of a different configuration
than that of the liquid line service fitting 26. However, the
principles of the present invention are not limited in any manner
to an R134a refrigerant circuit. To place the additive liquid 10
into the refrigerant circuit 12 using a first method of the present
invention, the interior 30 of the canister 28 (see FIG. 1) is
communicated with the interior of the refrigerant circuit 12, using
a conventional R134a refrigerant recharge hose assembly 42 which is
illustrated in phantom for purposes of illustrative clarity.
[0027] Recharge hose assembly 42 includes a quick disconnect
fitting 44 (or another type of connection fitting such as a
threaded fitting) interconnected by a length of refrigerant
charging hose 46 to an internally threaded tapping/dispensing valve
48 having a rotatable handle 50 useable to axially drive a piercing
stem portion 52 of the valve 48. To ready the canister 28 for use
in placing the additive liquid 10 into the refrigerant circuit 12,
the tapping/dispensing valve 48 (with its piercing stem 52 in an
upwardly retracted position) is threaded onto the tubular
projection 38 of the canister 28, and the quick disconnect fitting
44 is connected to the suction line service port 24.
[0028] With the air conditioning system 14 running, and refrigerant
being operatively flowed through the suction line portion 12a at a
vacuum pressure greater than that in the partially evacuated
canister interior 30, the tapping/dispensing valve handle 50 is
operated to pierce the upper end 40 of the canister projection 38
and place canister interior 30 in communication with the interior
of the suction line portion 12a. As indicated by the arrows 54 in
FIG. 1, the higher vacuum pressure in the suction line portion 12a
draws the additive liquid 10 from the partially evacuated canister
interior 30 into the suction line portion 12a, thereby emptying the
canister 30 of its additive liquid content as shown in FIG. 2.
[0029] This higher vacuum pressure emptying of the canister 28 may
be facilitated by inverting the 28 and holding it higher than the
suction line service fitting 24. After the additive liquid 10 is
placed into the refrigerant circuit in this manner, the refrigerant
recharge hose assembly 42 is disconnected from the service fitting
24 and the canister 28 and the now emptied canister 28
discarded.
[0030] With continued reference to FIGS. 1 and 2, a second method
of utilizing the specially designated, partially evacuated canister
28 to place its additive liquid 10 into the refrigerant circuit 12
is to communicate the interior 30 of the canister 28 with the
interior of the refrigerant circuit (e.g., at its suction line
portion 12a), using the hose assembly 42, while the refrigerant
circuit 12 has been emptied for repair and has a service vacuum
pressure within the interior 30 of the canister 28. The service
vacuum pressure within the refrigerant circuit 12 pulls the
additive liquid 10 from the canister interior 30 into the
refrigerant circuit 12 as indicated by the arrows 54 in FIG. 1.
[0031] A third method of utilizing the specially designed,
partially evacuated canister 28 to place its additive liquid 10
into the refrigerant circuit 12 is schematically illustrated in
FIGS. 3 and 4 to which reference is now made. Utilizing this second
method, with the air conditioning system 14 initially being turned
off, so that refrigerant is not being flowed through the circuit 12
and a positive pressure is present in the interior of the suction
line portion 12a, the partially evacuated canister 28 is
interconnected via the hose assembly 42 to the suction line service
fitting 24, with the tapping/dispensing valve 48 being in its
closed position, as previously described. The valve handle 50 is
then rotated to axially drive the stem 52, pierce the canister
projection 38, and initially communicate the partially evacuated
canister interior 30 with the positively pressurized refrigerant
within the suction line portion 12a.
[0032] As depicted in FIG. 3, this causes positively pressurized
refrigerant 56 from within the interior off the suction line
portion 12a to be forcibly flowed into the partially evacuated
canister interior 30 via the hose 46, as indicated by the arrows 58
in FIG. 3, to become in effect a carrier for the additive liquid
10. Next, the air conditioning system 14 is turned on to create an
operative flow of refrigerant 56 through the circuit 12 and
generate in the suction line portion 12a a vacuum pressure. The
positive pressure previously created in the interior 30 of the
canister 28 by the forcible injection of refrigerant 56 thereinto
causes the liquid additive and refrigerant 10,56 within the
canister interior 30 to be flowed into the suction line portion
12a, via the hose 46, as indicated by the arrows 60 in FIG. 4,
thereby substantially emptying the canister 28 of its refrigerant
and additive contents. This transfer of refrigerant and additive to
the circuit 12 may be facilitated by inverting the canister 28 and
positioning it at a higher level than that of the suction line
service fitting 24. After such transfer is completed, the
refrigerant recharge hose assembly 42 is disconnected from the
canister 28 and the service fitting 24, and the emptied canister 28
discarded.
[0033] The provision and use of the specially designed partially
evacuated canister 28 provides a variety of advantages over
conventional pressurized canisters containing refrigerant and
liquid additive. For example, since there is no refrigerant in the
canister, the same canister can be used with a wide variety of air
conditioning or refrigeration systems that utilize different types
of refrigerants--the canister does not have to be "matched" to a
particular type of refrigerant in a circuit in order to avoid
contamination thereof by a different type of refrigerant within the
canister.
[0034] Moreover, since refrigerant is not packaged within the
canister, the material cost of the partially filled canister is
substantially reduced. Additionally, since there is no refrigerant
disposed within the as-manufactured canister it cannot leak
refrigerant into the atmosphere, and the lack of pressurized
refrigerant within the as-manufactured canister renders it safer to
ship and store.
[0035] The pressurization can be a refrigerant gas which carries
along with it the various additives as discussed above. The
dehydrating and sealing compositions preferably each include at
least one compound and generally include two or more compounds of
each requirement for dehydration, metal sealing and rubber sealing.
The object of the present invention is to provide an improved air
conditioning system treatment composition, in which the improvement
provides for the combination of a drying agent, a
moisture-activated metal treatment and a rubber rejuvenating
compound into a single container, unlike conventional air
conditioning systems where multiple containers are used. The
improved air conditioning system treatment composition comprises of
a binding azeotrope like material, the binding azeotrope is
preferred to be methanol and cyclohexanone combined with a drying
agent, a moisture activated metal treatment and a rubber
rejuvinating material. The combination of a binding azeotrope of
methanol and cyclohexanone with a drying agent, and a moisture
activated metal treatment and rubber rejuvinating compound into a
single container is not known.
[0036] For purposes of this invention, a mixture of two or more
components is azeotropic if it vaporizes with no change in the
composition of the vapor from the liquid. Specifically, azeotropic
mixtures include both mixtures that boil without changing
composition, and mixtures that evaporate at a temperature below the
boiling point without changing composition. Accordingly, an
azeotropic mixture may include mixtures of two components or more
over a range of proportions for each specific proportion of the
components is azeotropic at a certain temperature but not
necessarily at other temperatures. Azeotrope and azeotrope like
compositions vaporize with no change in their composition. If the
applied pressure is above the vapor pressure of the azeotrope, the
azeotrope evaporates without change. If the applied pressure is
below the vapor pressure of the azeotrope, the azeotrope boils or
distills without change. The vapor pressure of low boiling
azeotropes is higher and the boiling point is lower than that of
the individual components. In fact, the azeotropic composition has
the lowest boiling point of any composition of its components.
Thus, the azeotrope can be obtained by distillation of a mixture
whose composition initially departs from that of the azeotrope.
Azeotropes can exist in systems containing two liquids (A and B) as
binary azeotropes, three liquids (A, B and C) as ternary
azeotropes, and four liquids (A, B, C, and D) as quarternary
azeotropes.
[0037] For purposes of this invention, other alcohols can be used
in combination as an azeotrope. The term alcohols represents a
broad class of hydroxyl-containing organic compounds. For example,
monohydric alcohols of about one to three carbon atoms can be used
or various dihydric, trihydric and polyhydric alcohols for forming
azeotropes suitable for the present inventive mix. Furthermore,
these alcohols when dehydrated act as a water scavenger. Even
though the alcohols are used in the azeotropes or azeotrope like
mixtures. These dehydrated alcohols can be a part of the azeotrope
or can operate independently as a water scavenger. Those dehydrated
alcohols which do form azeotropes or azeotrope like mixtures can
also scavenge water.
[0038] In one preferred method and composition, the sealing
compositions which are preferably added to the dehydrating
compositions and the passivating compositions for a one time
injection into the refrigerant system function with and are
compatible with each other. The sealing compositions circulate
within the fluid enclosure within the system as does the
passivating and dehydrating compositions. If the system has a leak,
the sealing composition exits through the leak and hydrolytically
reacts with moisture in the atmosphere to form a polymeric seal on
the external surface of the system.
[0039] Preferred fluorocarbon-based working fluids useful in
conjunction with the compositions of the additive fluids of the
present invention include those having a numerical fluorocarbon
code designated by the American Society of Refrigerating Engineers
(ASRE). Preferred ASRE codes include 11, 12, 12B1, 13, 13B1, 14,
21, 22, 32, 42, 115, 124, 125, 134,R134a, 143a, 152a, 161, 218, and
227.
[0040] Preferably, the working fluids chosen are compatible with
the compositions used in the methods and fluid mixes and the
compositions are chosen to be soluble in the working fluid, the
lubricant or both the working fluid and the lubricant. In one
embodiment, the composition can be chosen so that one compound
within the composition is preferentially soluble in the working
fluid and the other compound in the composition is preferentially
soluble in the lubricant. It should be understood, based on this
disclosure, that other working fluids meeting the above-criteria
may be used with the present compositions without departing from
the spirit of the invention.
[0041] The invention will now be described in more detail with
respect to the following specific, non limiting example:
EXAMPLE
[0042] The passivation effect, the dehydrating compositions as well
as the sealants of the present invention in combination with the
azeotropes and carrier material is demonstrated by comparing the
surface energies of untreated substrates through the surface
energies of substrates traded with the various additives. Various
additives all contain silanes and organic silanes for cross-linking
metal bonding and rubber sealants. High surface energies are
indicated by low contact angles due to polar attractions. The
removal of the polar nature of the surface by incorporation of
silicon groups repels highly polar water molecules resulting in
high contact angles (which can approach 90 degrees) indicating
lower surface energy.
[0043] A typical vacuum pack contains from about one and a half
ounces of refrigerant additives to greater quantities and size of
the pack depending on the need. The one and a half ounces of
additive is comprised of 3/4 ounce of metal sealants having the
composition of 60% by volume of vinyltrimethoxysilane, 30% by
volume of n-beta(aminoethyl)gamma-aminoprop- yltrymethoxysilane;
and 10% by volume of methyltrimethoxysilane, a water scavenger. The
other additive constituting 3/4 of an ounce of a 11/2 ounce vacuum
pack load is comprised of 50% by volume methanol and 3% by volume
of (1) a mix comprising 35% by volume cyclohexanone and 65% by
volume methylene chloride; and 47% PAG. These two additive mixtures
and azeotropes are carried by R134a carrier which constitutes
another 1/2 ounce load for the vacuum packed load, bringing the
total to 3 ounces. These additives specifically mentioned are
joined together in an azeotropic mixture which allows the user to
load his vacuum pack or other delivery packaging systems with
various amounts, however in this case a total of 3 ounces of
additives and R134a carrier, which constitutes the refrigerant in
most cases. In review, the methyltryoxysilane is a water scavenger
and the vinyl trimethylsilane is a metal bonding material which the
n-beta-(aminoethyl)-gamma-aminopropyltrymethoxysilane is for cross
linking. While the methanol and cyclohexanone do provide the
azeotrope with the cyclohexanone acting as a penetrant and methyl
chloride as a softener. The final component is PAG which is
polyalkylene glycols (PAGs) and polyol esters which constitute the
new lubricants suitable for R134a refrigerants and the like. The
water in a system using these lubricants does cause hydrolysis of
the lubricating esters in a chemical reversion process. The
foregoing detailed description is to be clearly understood as being
given by way of illustration and example only, the spirit and scope
of the present invention being limited solely by the appended
claims.
* * * * *