Hot gas heat exchanger

Claim 2

A hot gas heat exchanger for vaporizing cryogenic liquids comprising a burner for producing a continuous stream of highly heated gas, a chamber for receiving the gas stream having fluid passages adapted to contain combustible cryogenic fluid in liquid and vapor phases in heat transfer relation to the gas stream, and means located upstream from the heat transfer passages for injecting water directly into the maIn hot gas stream for rapidly generating steam and producing a gas-steam heat transfer mixture that materially increases the heat transfer mass of the stream for efficiently vaporizing the cryogenic liquid at reduced stream temperature, and that is sufficiently inert for maintaining a substantially non-combustible atmosphere in the heat exchanger.

Claim 3

A hot gas heat exchanger as specified in claim 1 wherein the cryogenic liquid passages define multiple loops disposed in the path of the gas stream, and the water injecting means is spaced a sufficient distance upstream for substantial vaporization of the water into steam prior to initial heat transfer contact of the gas-steam mixture with the liquid passage loops.

Claim 4

A hot gas heat exchanger for vaporizing cryogenic liquids comprising a jet engine providing at its exhaust a stream of hot gas, a chamber for receiving the gas stream having passages adapted to contain a cryogenic liquid in heat transfer relation to the gas stream, and means located upstream from the heat transfer passages for injecting water into the hot gas stream for reducing the temperature thereof and producing a gas-steam heat transfer mixture, thereby increasing the heat transfer mass of the stream for efficiently vaporizing the cryogenic liquid within the passages, and a plurality of pumps that operate respectively by power takeoff from the engine and produce respectively flow of injection water, flow of cryogenic liquid through the heat transfer passages, and return of cold-surface condensate from the chamber to the injection water supply.

Claim 5

A hot gas heat exchanger for vaporizing cryogenic liquids comprising a jet engine providing at its exhaust a stream of hot gas, a chamber for receiving the gas stream having passages adapted to contain a cryogenic liquid in heat transfer relation to the gas stream, and means located upstream from the heat transfer passages for injecting water into the hot gas stream for reducing the temperature thereof and producing a gas-steam heat transfer mixture, thereby increasing the heat transfer mass of the stream for efficiently vaporizing the cryogenic liquid within the passages, and a plurality of pumps that operate respectively by power takeoff from the engine and produce respectively flow of injection water, flow of cryogenic liquid through the heat transfer passages, and return of cold-surface condensate from the chamber to the injection water supply.

Claim 6

A hot gas heat exchanger as specified in claim 1 wherein the injecting means injects water into the hot gas stream so as to generate sufficient steam for maintaining a substantially inert heat transfer mixture at the heat transfer passages and for maintaining the inert atmosphere at reduced temperature for preventing overheating in the passages.

Claim 7

A hot gas heat exchanger as specified in claim 2 wherein burner means produce highly heated combustion gases, and the injection water generates quantities of steam for materially increasing the heat transfer mass of the resulting reduced temperature gas-steam mixture, the cooled gas-steam mixture is guided into heat transfer relation with the multiple loops for vaporizing the cryogenic liquid to a product gas, and recycling means collect the resulting steam condensate from the loops for injection water.

Claim 8

A heat exchanger for vaporizing cryogenic liquid comprising burner means adapted to generate hot gases, conduit means to direct the hot gases from the burner means to a point of exhaust to the atmosphere, means to spray water into the hot gases passing through the conduit means whereby the water is vaporized and the temperature of the hot gases is lowered, passage means in said conduit means downstream of said spray means, means to introduce cryogenic liquid into said passage means and means to collect the water condensed on said passage means and return it to the water spray means.

Claim 9

A heat exchanger for vaporizing cryogenic liquid comprising burner means adapted to generate hot gases, conduit means to direct the hot gases from the burner means to a point of exhaust to the atmosphere, means to spray water into the hot gases passing through the conduit means whereby the water is vaporized and the temperature of the hot gases is lowered, passage means in said conduit means downstream of said spray means, means to introduce cryogenic liquid into said passage means and means to collect the water condensed on said passage means and return it to the water spray means.

Claim 10

A heat exchanger as defined in claim 6 wherein the water spray means comprises a plurality of nozzles directing the spray in a downstream direction.

Claim 11

A heat exchanger as defined in claim 6 wherein the means to introduce cryogenic liquid includes a pump connected to a storage source.

Claim 12

A heat exchanger as defined in claim 6 wherein the passage means includes a tube coil.

Claim 13

A heat exchanger as defined in claim 8 wherein the cryogenic liquid is liquefied natural gas.

Claim 14

A heat exchanger as defined in claim 6 wherein the conduit means at the point of gas exhaust to atmosphere, constitutes a flue having a water separator for recovering part of the uncondensed spray water.