Heat exchanger liquid refrigerant defrost system

A heat exchange liquid defrost system used with a building heat exchange system, that includes a compressor, an indoor heat exchange coil system, a main liquid conduit connected between said compressor and said indoor heat exchange coil system, at least one metering device connected to said main liquid refrigerant line and at least one control valve connected to said main liquid refrigerant line to control the direction of flow of liquid refrigerant through said heat exchange system, said heat exchange liquid defrost system comprising:

• a. an outer housing;
• b. at least two coil subsystems located inside said outer housing, each said coil subsystem includes an inlet tubing section, a t-joint, a first end tube section, a main body section, and a second end tube section, said inlet tubing section being connected at one end to said main liquid refrigerant line from said indoor heat exchanger, said t-joint being disposed between said inlet tubing section, said main body section, and said first end tube section;
• c. a bypass solenoid located in said inlet tubing section of each said coil subsystem capable of controlling the flow of liquid refrigerant therethrough;
• d. a suction line solenoid located in said first end tube section used to control the flow of refrigerant therethrough, the closing and opening operation of said suction line solenoid being opposite to the closing and opening operation of said bypass solenoid;
• e. a metering device located in said second tube section, said metering device being used to change the state of a refrigerant from a liquid flowing through said second tube section to a vapor;
• f. a first bypass check valve located in said second tube section, said first bypass check valve being open to allow the flow of liquid refrigerant through said second tube section when said metering device connected to said second tube section is not used to change the state of said refrigerant flowing through said second tube section;
• g. an outdoor refrigerant transfer line that extends between said suction line solenoid used on each said coil subsystem and connects to said compressor used on said building heat exchange system;
• h. a secondary liquid line that extends between each said meter device and said first bypass check valve in each said coil subsystem and connects to said main liquid refrigerant line;
• i. a restrictor valve disposed in said secondary liquid line between said main liquid refrigerant line and the last coil subsystem, said restrictor valve functioning is an open or close direction opposite the open and close direction of said bypass solenoid;
• and,
• j. means for controlling the operation of said bypass solenoid and said suction line solenoid so that said coil subsystems may be individually defrosted with liquid refrigerant from said indoor heat exchange coil system.