US2511993A

US2511993A - Azeotropic mixture for use as a refrigerant

Info

Publication number: US2511993A
Application number: US694145A
Authority: US
Inventors: Reed Winston Harrison
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1946-08-30
Filing date: 1946-08-30
Publication date: 1950-06-20
Anticipated expiration: 1967-06-20

Description

Patented June 20, 1950 L AZEOTROPIC MIXTURE FOR USE AS A REFRIGERANT Winston Harrison Reed, Syracuse, N. Y., assignor to Carrier Corporation, Syracuse, N. Y., a corporation of Delaware No Drawing. Application August 30, 1946, Serial No. 694,145

3 Claims. 1

This invention relates to refrigerant mixtures and to a method of using the same.

The chief object of my invention is to provide a refrigerant mixture composed of two or more refrigerants capable of forming an azeotropic mixture, which boils at a constant temperature as if it were composed of a single substance.

I have found a mixture of monochlorodifiuoromethane and propane to be particularly advantageous. Monoohlorodifluoromethane possesses a boiling point of -41.4 F. at atmospheric pressure while propane possesses a boiling point of --48.1 F. at atmospheric pressure (14.69 pounds per square inch). Monochlorodifluoromethane at a temperature of 32 F. provides a pressure of about 73 pounds per square inch absolute. Propane at a temperature of 32 F. possesses a pressure of about '75 pounds per square inch absolute. According to Raoults law, any mixture of such materials should possess a pressure between 20 the two extremes. Contrary to this law, however, the addition of propane to monochlorodifluoromethane increases the pressure over a wide range to provide a highly desirable increase in capacity of a refrigeration system designed for While I have described a preferred embodiconsisting in introducing into a refrigeration use with monochlorodifluoromethane. Such increase in capacity amounts to about 18% depending upon the quantity of propane mixed with monochlorodifluoromethane.

The azeotropic mixture is formed having a constant boiling point of 32 F. at an absolute pressure of approximately 86.2 pounds per square inch when monochlorodifluoromethane and propane are mixed in the proportions of approximately 68 parts to 32 parts by weight. The azeotropic mixture so formed possesses a lower boiling point than either monochlorodlfluoromethane or propane. The azeotropic mixture is stable, non-corrosive in the system and is lower in cost than monochlorodifiuoromethane.

The azeotropic mixture of my invention may be employed in equipment designed for use at a condensing temperature of about 105 F. and at an evaporating temperature of about 40 F. In operation the azeotropic mixture may be condensed at a condensing temperature of about 105 F., then transferred to the evaporator or heat exchanger and evaporated at a. temperature of about 40 F. to provide the required heat transfer.

It will be appreciated that the respective amounts of propane and monochlorodifluoromethane in the azeotrope vary in accordance with temperature and pressure; that is, the amount of propane contained in the azeotrope varies slightly as the temperature, for example, increases.

system of a refrigerant consisting of monochlorodifluoromethane having a boiling point of -41.4 F. at atmospheric pressure and propane having a boiling point of about -48.1 F. at atmospheric pressure, the refrigerant having a boiling point of 32 F. at about 86.2 p.s.i.a., evaporating the refrigerant, the concentration of the refrigerant remainin the same as it is vaporized with each of the components remaining in the same ratio with respect to the other, and then successively compressing and condens ing the refrigerant, the components in the refrigerant remaining in the same ratio during the compression and condensation stages.

2. A refrigerant for use in a compressorcondenser-expander refrigeration system consisting of a mixture of monochlorodifluoromethane and propane having a pressure at a predetermined temperature greater than the pressure of either component at such temperature, said mixture at its boiling temperature containing the same proportions of the components in both liquid and vapor phases.

3. A refrigerant for use in a compressor-condenser-expander refrigeration system consisting of an azeotropic mixture of monochlorodifluoromethane and propane and containing approximately 32% by weight of propane, said mixture having a boiling point of 32 F. at an absolute pressure of about 86.2 pounds per square inch, said mixture at its boiling temperature containing the same proportions of the components in both liquid and vapor phases.

' WINSTON HARRISON REED.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

Claims

1. A METHOD OF PRODUCING REFRIGERATION EFFECT CONSISTING IN INTRODUCING INTO A REFRIGERATION SYSTEM OF REFRIGERANT CONSISTING OF MONOCHLORODIFLUOROMETHANE HAVING A BOILING POINT OF -41.4*F. AT ATMOSPHERIC PRESSURE AND PROPANE HAVING A BOILING POINT OF ABOUT -48.1*F AT ATMOSPHERIC PRESSURE, THE REFRIGERANT HAVING A BOILING POINT OF 32*F. AT ABOUT 86.2 P.S.I.A., EVAPORATING THE REFRIGERANT, THE CONCENTRATION OF THE REFRIGERANT REMAINING THE SAME AS IT IS VAPORIZED WITH EACH OF THE COMPONENTS REMAINING IN THE SAME RATIO WITH RESPECT TO THE OTHER, AND THEN SUCCESSIVELY COMPRESSING AND CONDENSING THE REFRIGERANT, THE COMPONENTS IN THE REFRIGERANT REMAINING IN THE SAME RATIO DURING THE COMPRESSION AND CONDENSATION STAGES.