Refrigeration system

Claim 2

An open cycle ammonia refrigeration system comprising: a. a storage tank for liquid ammonia refrigerant; b. a tubular evaporator wherein the liquid refrigerant is vaporized by absorbing heat from the surroundings of the evaporator; c. a first conduit for conveying the liquid refrigerant from the storage tank to the evaporator; d. a second conduit for conveying vaporized refrigerant from the evaporator to combusting means; e. means for combusting the vaporized refrigerant; f. a vapor-liquid sensing unit disposed at an intermediate point between the tubular evaporator entry and exit in heat transfer contact with the refrigerant flowing through the evaporator, said vapor-liquid sensing unit comprising a heat conductive element and means for heating said heat conductive element whereby the temperature of the heat conductive element will vary as a result of heat abstraction by refrigerant in heat transfer contact, the variation in temperature dependent on the proportion of liquid and vapor refrigerant; and g. means for regulating the flow of the refrigerant through the tubular evaporator actuated by said vapor-liquid sensing unit, said means interposed in said first conduit.

Claim 3

A refrigeration system as claimed in claim 1 wherein said vapor-liquid sensing unit is disposed in the tubular evaporator in the path of and in direct contact with the flowing refrigerant.

Claim 4

A refrigeration system as claimed in claim 1 wherein said vapor-liquid sensing unit is disposed externally to the tubular evaporator in indirect heat transfer contact with refrigerant flowing through the evaporator.

Claim 5

A refrigerant system as claimed in claim 1 wherein the means for heating said heat conductive element is electrical resistance.

Claim 6

A refrigerant system as claimed in claim 1 wherein the means for heating said heat conductive element is a heated member is contact with said element whereby heat is conducted from said member to said element.

Claim 7

A refrigerant system as claimed in claim 1 wherein a member is provided a conduct heat from the combustion means to the heat conductive element.

Claim 8

A refrigerant system as claimed in claim 1 wherein the evaporator is composed of a plurality of tubular coils thru which the refrigerant flows in parallel coils and a single tubular coil through which the refrigerant discharges from the plurality of tubular coils.

Claim 9

A refrigerant system as claimed in claim 7 wherein the vapor-liquid sensing unit is disposed near the inlet of the single tubular coil into which the refrigerant discharges.

Claim 10

A refrigeration system as claimed in claim 1 wherein the means for regulating the flow of the refrigerant through the evaporator includes a liquid feed control valve disposed in the first conduit in communication with said vapor-liquid sensing unit, whereby the liquid refrigerant is prevented from entering the means for combusting vaporized refrigerant.

Claim 11

A refrigeration system as claimed in claim 1 including a thermostatic control valve disposed in the first conduit in communication with a temperature sensing element located in a refrigerated compartment surrounding the tubular evaporator.

Claim 14

A method as claimed in claim 11 wherein the flow of refrigerant through the tubular evaporator is regulated, actuated by variation in temperature of said heat conductive element.

Claim 15

A method as claimed in claim 11 wherein the vapor-liquid sensing unit actuates valve means to regulate the flow of the refrigerant through the evaporator to obtain 5 to 25 percent liquid refrigerant at the point of the vapor-liquid sensing unit.

Claim 16

An open cycle refrigeration system comprising: a. a storage tank for liquid ammonia refrigerant; b. a tubular evaporator wherein the liquid refrigerant is vaporized by absorbing heat from the surroundings of the evaporator; c. a first conduit for conveying a liquid refrigerant from the storage tank to the evaporator; d. a second conduit for conveying vaporized refrigerant from the evaporator to combusting means; e. means for combusting the vaporized refrigerant; f. vapor-liquid sensing unit disposed at an intermediate point between the tubular evaporator entry and exit in heat transfer contact with the refrigerant flowing through the evaporator such that the heat transfer surface area of an auxiliary portion of the tubular evaporator located on the discharge side of said vapor-liquid sensing unit ranges from about one-fourth to one-third of the total heat transfer area of the tubular evaporator, said vapor-liquid sensing unit comprising a heat conductive element and means for heating said heat conductive element whereby the temperature of the heat conductive element will vary as a result of heat abstraction by refrigerant in heat transfer contact, the variation in temperature dependent on the proportion of liquid and vapor refrigerant; and g. interposed in said first conduit, means for regulating the flow of the refrigerant through the tubular evaporator actuated by said vapor-liquid sensing unit.

Claim 17

An open cycle refrigeration system comprising: a. a storage tank for liquid ammonia refrigerant; b. a tubular evaporator wherein the liquid refrigerant is vaporized by absorbing heat from the surroundings of the evaporator; c. a first conduit for conveying a liquid refrigerant from the storage tank to the evaporator; d. a second conduit for conveying vaporized refrigerant from the evaporator to combusting means; e. means for combusting the vaporized refrigerant; f. vapor-liquid sensing unit disposed at an intermediate point between the tubular evaporator entry and exit in heat transfer contact with the refrigerant flowing through the evaporator such that the heat transfer surface area of an auxiliary portion of the tubular evaporator located on the discharge side of said vapor-liquid sensing unit ranges from about one-fourth to one-third of the total heat transfer area of the tubular evaporator, said vapor-liquid sensing unit comprising a heat conductive element and means for heating said heat conductive element whereby the temperature of the heat conductive element will vary as a result of heat abstraction by refrigerant in heat transfer contact, the variation in temperature dependent on the proportion of liquid and vapor refrigerant; and g. interposed in said first conduit, means for regulating the flow of the refrigerant through the tubular evaporator actuated by said vapor-liquid sensing unit.