Refrigeration – Processes – Employing diverse materials or particular material in...
Reexamination Certificate
1995-02-28
2002-01-08
Doerrler, William (Department: 3744)
Refrigeration
Processes
Employing diverse materials or particular material in...
C252S067000
Reexamination Certificate
active
06336333
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
This invention relates to a novel refrigerant mixture for use in refrigeration systems. The refrigerant is not harmful to the ozone layer, and is particularly applicable in systems such as automobile air-conditioning and home refrigeration.
BACKGROUND OF THE INVENTION
A continuing demand exists for a simple, inexpensive refrigerant which can be used to reduce the level of ozone damaging compounds which can escape and harm the earth's atmosphere. In particular, there exists a need for a simple, low cost refrigerant which can be used as a substitute for refrigerant R-12, also commonly known as dichlorodifluoromethane. At normal atmospheric pressure, R-12 boils a −21.7° F., thus, any substitute must have properties sufficiently comparable that equipment can be used without costly modification.
In addition to the undesirable ozone depletion consequences which have been widely reported, those familiar with refrigeration systems will also recognize that R-12 and other fluorchlorocarbon refrigerants can contribute to the formation of acids under as a result of decomposition in a refrigerant system. Formation of such acids is not uncommon, and when it occurs, severe damage to metal surfaces in a refrigerant system can result. Moisture in an R-12 based refrigeration system can contribute to such acid formation, as can use of contaminated lubricating oils.
For the most part, the R-12 substitutes which have been proposed have been various substituted hydrocarbons, utilizing addition of bromine or other atoms, primarily in an attempt to produce a non-flammable refrigerant. Such substitutes have their own problems, such as undesirable toxicological effects on exposed individuals.
SUMMARY OF THE INVENTION
I have now invented, and disclose herein, a novel, refrigerant mixture which does not have the above-discussed drawbacks common to the fluorchlorocarbon refrigerants heretofore used of which I am aware. Unlike the refrigerants heretofore available, my product is simple, relatively inexpensive, easy to manufacture, and otherwise superior to those heretofore used or proposed. In addition, it provides a significant, demonstrated improvement with regard to protection against release of ozone depleting compounds.
Another important feature is the fact that my novel refrigerant is not conducive to formation of undesirable acid compounds while in use in a refrigeration system. This provides a unique safety feature when compared to many previously known refrigerants.
My novel refrigerant mixture is essentially a 50-50 mixture of propane and butane. However, up to as much as 75% of propane, or alternately, butane, may be utilized.
My novel refrigerant differs from those prior art products mentioned above in one respect in that no substitution of hydrogen molecules by halogen or other species is required. In its simplest form, my invention is the discovery that a mixture of propane and butane will provide suitable properties for direct substitution in R-12 systems.
Thus, the dual advantages of protection of the ozone layer, and low cost of the commonly available gases propane and butane gases, become important and self-evident in direct refrigerant substitution applications.
OBJECTS, ADVANTAGES, AND FEATURES OF THE INVENTION
From the foregoing, it will be apparent to the reader that one important and primary object of the present invention resides in the provision of a novel, improved refrigerant which does not contribute to the destruction of the ozone layer.
Other important but more specific objects of the invention reside in the provision of a refrigerant which may be directly substituted in R-12 based refrigeration systems, and which:
can be manufactured in a simple, straightforward manner;
results in comparatively low cost refrigerant mixtures;
in conjunction with the preceding object, have the advantage that they can be widely used without cost penalty in selected refrigeration systems; and,
which provides a refrigerant gas mixture which is easy to use, install and remove.
Other important objects, features, and additional advantages of my invention will become apparent to the reader from the foregoing and the appended claims and as the ensuing detailed description and discussion proceeds in conjunction with the accompanying drawing.
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Toro, Taryn, Germ
Doerrler William
Goodloe, Jr. R. Reams
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