Process for embrittling integuments of small seeds

Claim 2

A process for embrittling the integuments of small seeds, comprising cooling the seeds by thermal shock in a fluidized bed; said cooling being by direct injection of a cryogenic fluid of liquid nitrogen or liquid carbon dioxide flash evaporated in a fluidized bed and constituting the fluidization gas in the gaseous state; setting in motion the major part of the fluidization gas to circulate in a closed circuit; and recovering cold by countercurrent circulation with the seeds of the other part of the fluidization gas removed from the cooling zone at a temperature close to the seed introduction temperature, to precool said seeds by countercurrent heat exchange.

Claim 3

A process according to claim 1, wherein impermeable leguminous seeds are treated with a view to favoring their eventual germination.

Claim 4

A process according to claim 1, wherein oleaginous seeds are treated with a view of facilitating their decortication.

Claim 5

A process in accordance with claim 1, wherein said precooling is carried out in a fluidized bed at a superatmospheric pressure.

Claim 6

A process for decorticating oleaginous seeds comprising subjecting the seeds to treatment in several steps including: a. precooling, consisting of lowering the seed temperature from ambient temperature to about 0° C; b. main cooling by thermal shock in a fluidized bed to a temperature between -40° and -60° C, provided by direct injection of liquid nitrogen flash evaporated in the fluidized bed, in the gaseous state, constituting the fluidization gas; injection of liquid nitrogen being regulated by the temperature of the fluidized bed; and the majority of the fluidization nitrogen being circulated in a closed circuit; c. decorticating the shock cooled seeds by cryogenic crushing at a temperature between -40° and -60° C; d. reheating the decorticated seed, separating the seed kernels and the integuments, and entraining the various waste products by circulation of the other part of the fluidization nitrogen extracted from the cooling zone at a temperature of about 0° C with recovery of cold by heat exchange, and countercurrent circulation of the nitrogen and the seeds; e. heating the kernels in the vicinity of ambient temperature by a gas stream composed of superheated air and dry gaseous nitrogen from said precooling; f. filtering the wastes and recycling after filtration of the dry gaseous nitrogen to said precooling; and g. maintaining in balance the quantities of gas from the main cooling zone for recycling and extraction.

Claim 7

A process for decorticating oleaginous seeds comprising subjecting the seeds to treatment in several steps including: a. precooling, consisting of lowering the seed temperature from ambient temperature to about 0° C; b. main cooling by thermal shock in a fluidized bed to a temperature between -40° and -60° C, provided by direct injection of liquid nitrogen flash evaporated in the fluidized bed, in the gaseous state, constituting the fluidization gas; injection of liquid nitrogen being regulated by the temperature of the fluidized bed; and the majority of the fluidization nitrogen being circulated in a closed circuit; c. decorticating the shock cooled seeds by cryogenic crushing at a temperature between -40° and -60° C; d. reheating the decorticated seed, separating the seed kernels and the integuments, and entraining the various waste products by circulation of the other part of the fluidization nitrogen extracted from the cooling zone at a temperature of about 0° C with recovery of cold by heat exchange, and countercurrent circulation of the nitrogen and the seeds; e. heating the kernels in the vicinity of ambient temperature by a gas stream composed of superheated air and dry gaseous nitrogen from said precooling; f. filtering the wastes and recycling after filtration of the dry gaseous nitrogen to said precooling; and g. maintaining in balance the quantities of gas from the main cooling zone for recycling and extraction.

Claim 8

A decortication process according to claim 5, wherein the various steps of the process are conducted in an inert dry nitrogen atmosphere.

Claim 9

A liquid-nitrogen injection cooler for embrittlement of the integuments of small seeds by cooling the seeds by thermal shock in a fluidized bed by direct injection of liquid nitrogen, comprising two zones separated by a partition delimiting an inlet zone at a temperature close to the seed temperature and a cooling zone, means for injecting liquid nitrogen into said cooling zone, a control valve for said liquid nitrogen injection, a fluidization bed temperature monitoring probe for controlling the amount of liquid nitrogen injected, a fluidization gas closed circuit recirculation fan, and a valve for balancing the quantities of recycled and extraction gas.

Claim 10

A liquid-nitrogen injection cooler for embrittlement of the integuments of small seeds by cooling the seeds by thermal shock in a fluidized bed by direct injection of liquid nitrogen, comprising two zones separated by a partition delimiting an inlet zone at a temperature close to the seed temperature and a cooling zone, means for injecting liquid nitrogen into said cooling zone, a control valve for said liquid nitrogen injection, a fluidization bed temperature monitoring probe for controlling the amount of liquid nitrogen injected, a fluidization gas closed circuit recirculation fan, and a valve for balancing the quantities of recycled and extraction gas.

Claim 11

Apparatus for decorticating oleaginous seeds by cooling the seeds by thermal shock in a fluidized bed by direct injection of liquid nitrogen, comprising a first thin-layer fluidization table for precooling the seeds; a main liquid nitrogen injection cooler in which the seeds undergo a thermal shock in a thick layer; a crusher which may be cooled by liquid nitrogen injection; a second fluidization table in which the seeds are reheated to recover some of the cold remaining in the seeds; a filter in which the various waste products are separated; a third fluidization table supplied with dry gaseous nitrogen and hot air in which the kernals are finally heated.

Claim 12

Apparatus for decorticating oleaginous seeds by cooling the seeds by thermal shock in a fluidized bed by direct injection of liquid nitrogen, comprising a first thin-layer fluidization table for precooling the seeds; a main liquid nitrogen injection cooler in which the seeds undergo a thermal shock in a thick layer; a crusher which may be cooled by liquid nitrogen injection; a second fluidization table in which the seeds are reheated to recover some of the cold remaining in the seeds; a filter in which the various waste products are separated; a third fluidization table supplied with dry gaseous nitrogen and hot air in which the kernals are finally heated.