THERMAL EXPANSION VALVE REFRIGERATION SYSTEMS

• US 3,835,659 A
• Filed: 04/16/1973
• Issued: 09/17/1974
• Est. Priority Date: 04/16/1973
• Status: Expired due to Term

• Current Assignee: Lyle E. Mcbride Jr
• Original Assignee: Lyle E. Mcbride Jr
• Inventors: McBride, Lyle E. Jr.
• Primary Examiner(s): Perlin, Meyer
• Application Number:
  US05/351,749
• Time in Patent Office: 519 Days
• Field of Search: 62/202,222,223,224,225,211,236
• US Class Current: 62/202
• CPC Class Codes: F16K 31/025 actuated by thermo-electric means
• CPC Class Codes: F25B 2341/0683 the sensor is disposed in the suction line and influenced by the temperature or the pressure of the suction gas
• CPC Class Codes: F25B 41/355 by electric heating of bimetal elements, shape memory elements or heat expanding elements
• CPC Class Codes: Y02B 30/70 Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating

Abstract

This disclosure relates to a compact, reliable and inexpensive expansion valve for use in a refrigeration system. The valve has one passage to be arranged between the evaporator and the compressor of the refrigeration system and has a second passage to be arranged between the condenser and evaporator in the system. A valve member disposed in the second passage is spring biased to normally close that passage and a wire of a selected nickel-titanium alloy or the like is connected to the valve member and disposed in the first valve passage, this wire being adapted to abruptly contract in length for moving the valve member to open the second valve passage when the wire is heated above a selected transition temperature. A small electrical current is directed through the wire so that, when sufficient refrigerant has been released into the evaporator through the second valve passage, droplets of liquid refrigerant in the atmosphere moving from the evaporator to the compressor of the refrigeration system through the first valve passage cool the alloy wire and permit the noted spring bias to move the valve member to close the second valve passage. However, when no liquid droplets of refrigerant are present in the noted atmosphere, the alloy wire is heated to the noted temperature by the electrical current flowing through the wire, the wire then contracting in length for opening the second valve passage to allow more liquid refrigerant to enter the evaporator.

Claims

1. A refrigeration expansion valve system comprising valve body means defining a first passage to be arranged between an evaporator and a compressor in a refrigeration system, defining a second passage to be arranged between a condenser and said evaporator in said refrigeration system, and having a bore extending between said passages, valve seat means in said second passage, a valve member slidable in said bore between a position engaging said valve seat means for closing said second passage and a position spaced from said valve seat means for opening said second passage, spring means biasing said valve member to one of said positions, a pair of terminals extending in electrically insulated relation to each other into said first passage through said valve body means, and a wire electrically connected between said terminals within said first passage and secured to said valve member to be exposed to the cooling effect of the flow of gaseous and liquid refrigerant in said first passage, said wire being of a selected metal alloy to be deformed from an original length to a second length by said spring bias as said valve member is moved to said one position by said spring bias while said alloy displays a relaTively low modulus of elasticity below a transition temperature and to abruptly return to said original length and to display a relatively higher modulus of elasticity to move said valve member to the other of said positions against said spring bias when said wire is heated to said transition temperature and means directing electrical current through said wire between said terminals for heating said wire to said transition temperature while substantially gaseous refrigerant flows in said first passage and for permitting said wire to cool below said transition temperature in response to the flow of selected liquid refrigerant in said first passage.

2. A valve as set forth in claim 1 wherein said wire is formed of a selected nickel-titanium alloy.

3. A valve as set forth in claim 1 wherein said valve body means define said passages in parallel relation to each other having said bore extending between said passages in a direction normal to the axis of said passages and having said valve seat means disposed in a plane normal to the axis of said bore.

4. A valve as set forth in claim 1 wherein said spring means bias said valve member to said position closing said second valve passage.

5. A valve as set forth in claim 1 wherein said spring means bias said valve member to said position opening said second valve passage.

6. A valve as set forth in claim 1 wherein said valve body means is formed of metal and has a pair of apertures extending into said first passage, wherein said terminals extend into said first passage through said respective apertures, and wherein insulating bushing means secure said terminals within said apertures in sealing relation thereto and in electrically insulated relation to each other.

7. A valve as set forth in claim 6 wherein said terminals threadedly engage said respective insulating bushings for permitting adjustment of the extension of said terminals into said first passage.