Method and apparatus for flash freezing various products

Claim 2

Apparatus for flash freezing of articles comprising housing means defining a substantially thermally isolated process chamber, means including a conveyor operating in said chamber for transporting articles in succession along a process path leading into, through and out of said chamber, means including spray nozzle mechanism mounted within said chamber for directing a spray discharge of liquid nitrogen against each article at a certain region along said process path to flash at least partially to gas for freshly generating gaseous nitrogen within said chamber, pumping means operable concurrently with the spray discharge means and having a suction inlet and a discharge outlet communicating with generally transversely spaced lengthwise distributed locations flanking another region along said process path to develop high velocity stream flow traveling a generally transverse recirculation flow path distributed lengthwise through said chamber to impinge upon each article moving thereby, said stream flow being comprised partly of recirculated gaseous nitrogen and partly of freshly generated gaseous nitrogen, and means for withdrawing gaseous nitrogen from the apparatus at a rate for maintaining atmospheric pressure substantially throughout the remainder of said chamber.

Claim 3

Apparatus for flash freezing of articles comprising housing means defining a substantially thermally isolated process chamber, means including a conveyor operating in said chamber for transporting articles in succession along a process path leading into, through and out of said chamber, means including spray nozzle mechanism mounted within said chamber for directing a spray discharge of cryogenic liquid against each article at a certain region along said process path to flash at least partially to gas for freshly generating gas within said chamber, elongated internal housing means mounted in said chamber adjacent another longitudinal region of the process path and providing first and second plenum chambers flanking the last named region and having a multiplicity of lengthwise distributed openings communicating with generally transversely opposing regions bordering the process path, pumping means operable concurrently with the spray discharge means and having a suction inlet communicating with the first plenum chamber and a discharge outlet communicating with the second plenum chamber to develop high velocity gas stream flow traveling along a recirculation flow path leading from the second chamber to the first chamber and generally transversly intersecting the process path, along a region which extends for a substantial distance lengthwise of said process path and means for withdrawing gas from the apparatus at a rate for maintaining atmospheric pressure substantially throughout the remainder of said chamber.

Claim 4

Apparatus for flash freezing of articles comprising housing means defining a substantially thermally isolated process chamber, means including a conveyor operating in said chamber for transporting articles in succession along a process path leading into, through and out of said chamber, means including spray nozzle mechanism mounted within said chamber for directing a spray discharge of cryogenic liquid against each article at a certain region along said process path to flash at least partially to gas for freshly generating gas within said chamber, elongated internal housing means mounted in said chamber adjacent another longitudinal region of the process path and providing first and second plenum chambers flanking the last named region and having a multiplicity of lengthwise distributed openings communicating with generally transversely opposing regions bordering the process path, pumping means operable concurrently with the spray discharge means and having a suction inlet communicating with the first plenum chamber and a discharge outlet communicating with the second plenum chamber to develop high velocity gas stream flow traveling along a recirculation flow path leading from the second chamber to the first chamber and generally transversly intersecting the process path, along a region which extends for a substantial distance lengthwise of said process path and means for withdrawing gas from the apparatus at a rate for maintaining atmospheric pressure substantially throughout the remainder of said chamber.

Claim 5

Apparatus for flash freezing of articles comprising housing means defining a substantially thermally isolated process chamber, means including a conveyor within said chamber for transporting articles in succession along a process path leading into, through and out of said chamber, means including spray nozzle mechanism mounted within said chamber for directing a spray discharge of liquid nitrogen against each article at a downstream region along said process path to flash at least partially to gas for freshly generating gaseous nitrogen within said chamber, pumping means operable concurrently with the spray dischaRge means and having a suction inlet and a discharge outlet communicating with generally transversely spaced lengthwise locations flanking a downstream region along the process path to develop high velocity stream flow traveling a transverse recirculation flow path distributed lengthwise through said chamber to impinge upon each article moving thereby, said stream flow being comprised partly of recirculated gaseous nitrogen and partly of freshly generated gaseous nitrogen, and means for withdrawing gaseous nitrogen from the apparatus at a rate for maintaining atmospheric pressure substantially throughout the remainder of said chamber.

Claim 6

Apparatus for flash freezing of articles comprising housing means defining a substantially thermally isolated process chamber, means including a conveyor within said chamber for transporting articles in succession along a process path leading into, through and out of said chamber, means including spray nozzle mechanism mounted within said chamber for directing a spray discharge of liquid nitrogen against each article at a downstream region along said process path to flash at least partially to gas for freshly generating gaseous nitrogen within said chamber, pumping means operable concurrently with the spray dischaRge means and having a suction inlet and a discharge outlet communicating with generally transversely spaced lengthwise locations flanking a downstream region along the process path to develop high velocity stream flow traveling a transverse recirculation flow path distributed lengthwise through said chamber to impinge upon each article moving thereby, said stream flow being comprised partly of recirculated gaseous nitrogen and partly of freshly generated gaseous nitrogen, and means for withdrawing gaseous nitrogen from the apparatus at a rate for maintaining atmospheric pressure substantially throughout the remainder of said chamber.

Claim 7

Apparatus for flash freezing of articles comprising hollow housing structure defining a substantially thermally isolated process chamber having spaced apart upstream and downstream ends, an open mesh conveyor operating in said chamber for transporting articles in succession along a process path leading from the upstream end to the downstream end, a transfer conveyor leading to the upstream end of said open mesh conveyor, a transfer conveyor leading from the downstream end of the open mesh conveyor and means for preventing entrance of ambient air into said process chamber and including a separate tunnel enveloping each transfer conveyor and providing exfiltration flow of gaseous nitrogen from said chamber to ambient, means including spray nozzle mechanism mounted within said chamber for directing a spray discharge of liquid nitrogen generally vertically through said conveyor and against each article at a downstream region along said process path to flash at least partially to gas for freshly generating gaseous nitrogen within said chamber, pumping means operable concurrently with the spray discharge means and having a suction inlet and a discharge outlet communicating with generally transversely spaced lengthwise distributed locations flanking another region along the process path to develop high velocity stream flow traveling a generally transverse recirculation flow path distributed lengthwise through said chamber to impinge upon each article moving thereby, said stream flow being comprised partly of recirculated gaseous nitrogen and partly of freshly generated gaseous nitrogen, and means for withdrawing gaseous nitrogen from the apparatus at a rate for maintaining atmospheric pressure substantially throughout the remainder of said chamber.

Claim 8

Apparatus for flash freezing of articles comprising hollow housing structure defining a substantially thermally isolated process chamber having spaced apart upstream and downstream ends, an open mesh conveyor operating in said chamber for transporting articles in succession along a process path leading from the upstream end to the downstream end, a transfer conveyor leading to the upstream end of said open mesh conveyor, a transfer conveyor leading from the downstream end of the open mesh conveyor and means for preventing entrance of ambient air into said process chamber and including a separate tunnel enveloping each transfer conveyor and providing exfiltration flow of gaseous nitrogen from said chamber to ambient, means including spray nozzle mechanism mounted within said chamber for directing a spray discharge of liquid nitrogen generally vertically through said conveyor and against each article at a downstream region along said process path to flash at least partially to gas for freshly generating gaseous nitrogen within said chamber, pumping means operable concurrently with the spray discharge means and having a suction inlet and a discharge outlet communicating with generally transversely spaced lengthwise distributed locations flanking another region along the process path to develop high velocity stream flow traveling a generally transverse recirculation flow path distributed lengthwise through said chamber to impinge upon each article moving thereby, said stream flow being comprised partly of recirculated gaseous nitrogen and partly of freshly generated gaseous nitrogen, and means for withdrawing gaseous nitrogen from the apparatus at a rate for maintaining atmospheric pressure substantially throughout the remainder of said chamber.

Claim 24

Apparatus for flash freezing of articles comprising insulated housing structure defining a substantially thermally isolated process chamber, means for transporting articles along a process path extending through said chamber, and cooperating means for introducing liquid nitrogen into the chamber, converting the liquid nitrogen into relatively cold gaseous nitrogen within the chamber and discharging relatively warm gaseous nitrogen from the chamber in a relationship to produce and maintain a freezing environment of gaseous nitrogen in the chamber, said cooperating means including means for contacting liquid nitrogen with each article along a certain path region in said chamber to vaporize and freshly generate relatively cold gaseous nitrogen in said chamber, elongated internal wall means mounted in said chamber adjacent another longitudinal region of the process path to provide first and second plenum chambers flanking the last named region and having a multiplicity of lengthwise distribopenings communicating with generally transversely opposing chamber positions bordering said last named region and gas pumping means having a suction inlet communicating with the first plenum chamber and a discharge outlet communicating with the second plenum chamber to develop a relatively high velocity gaseous nitrogen stream traveling along a recirculation flow path leading from the openings of the second chamber to the openings of the first chamber and generally transversely intersecting the process path, said streams being comprised partly of recirculated gaseous nitrogen and partly of freshly generated gaseous nitrogen.

Claim 25

Apparatus for flash freezing of articles comprising insulated housing structure defining a substantially thermally isolated process chamber, means for transporting articles along a process path extending through said chamber, and cooperating means for introducing liquid nitrogen into the chamber, converting the liquid nitrogen into relatively cold gaseous nitrogen within the chamber and discharging relatively warm gaseous nitrogen from the chamber in a relationship to produce and maintain a freezing environment of gaseous nitrogen in the chamber, said cooperating means including means for contacting liquid nitrogen with each article along a certain path region in said chamber to vaporize and freshly generate relatively cold gaseous nitrogen in said chamber, elongated internal wall means mounted in said chamber adjacent another longitudinal region of the process path to provide first and second plenum chambers flanking the last named region and having a multiplicity of lengthwise distribopenings communicating with generally transversely opposing chamber positions bordering said last named region and gas pumping means having a suction inlet communicating with the first plenum chamber and a discharge outlet communicating with the second plenum chamber to develop a relatively high velocity gaseous nitrogen stream traveling along a recirculation flow path leading from the openings of the second chamber to the openings of the first chamber and generally transversely intersecting the process path, said streams being comprised partly of recirculated gaseous nitrogen and partly of freshly generated gaseous nitrogen.

Claim 26

Apparatus for flash freezing articles comprising a substantially thermally isolated chamber, conveyor means for transporting articles along a process path through the chamber, means for spraying liquid nitrogen against each article at one region along said path within the chamber to flash the liquid nitrogen at least partially to gas and generate fresh gaseous nitrogen within the chamber, means for creating a high velocity flow of gaseous nitrogen generally transverse to the direction of the process path across a second region which region extends for a substantial distance lengthwise of said process path, said flow-creating means including blower means, suction inlet means at a location bordering the process path in said second region for supplying freshly generated gaseous nitrogen and gaseous nitrogen having flowed across said second region to said blower means and outlet means at a location generally bordering the opposite side of the process path in said second region for returning at least some of the gaseous nitrogen from said blower means to said process path, said high velocity flow of gaseous nitrogen being comprised partly of returned gaseous nitrogen and partly of freshly generated gaseous nitrogen from said one region, and means for discharging some of the gaseous nitrogen from said chamber to cause said freshly generated gaseous nitrogen to flow toward said suction inlet means.

Claim 27

Apparatus for flash freezing articles comprising a substantially thermally isolated chamber, conveyor means for transporting articles along a process path through the chamber, means for spraying liquid nitrogen against each article at one region along said path within the chamber to flash the liquid nitrogen at least partially to gas and generate fresh gaseous nitrogen within the chamber, means for creating a high velocity flow of gaseous nitrogen generally transverse to the direction of the process path across a second region which region extends for a substantial distance lengthwise of said process path, said flow-creating means including blower means, suction inlet means at a location bordering the process path in said second region for supplying freshly generated gaseous nitrogen and gaseous nitrogen having flowed across said second region to said blower means and outlet means at a location generally bordering the opposite side of the process path in said second region for returning at least some of the gaseous nitrogen from said blower means to said process path, said high velocity flow of gaseous nitrogen being comprised partly of returned gaseous nitrogen and partly of freshly generated gaseous nitrogen from said one region, and means for discharging some of the gaseous nitrogen from said chamber to cause said freshly generated gaseous nitrogen to flow toward said suction inlet means.