Cryogenic processing system for plant material
Devices and methods for improved separation of small particles from other stock. The device includes a sifting tray assembly and means for vibrating the screen of the sifting tray assembly for separating components and a cryogenic fluid source and injection system for freezing the small parts to the point where they are solid enough to pass through the screen without adhering to the screen. The method entails use of the system to separate small particles in sifting trays while spraying the stock with a cryogen such as liquid nitrogen.
1 . A method of separating small particles from plant stock, wherein said plant stock comprises large particles and small particles, said method comprising the steps of:
providing a particle separation system comprising a sifting tray assembly comprising (a) an inlet end with an inlet for large particles and small particles, (b) a means for separating the large particles from the small particles, (c) an outlet end with an outlet for discharge of the large particles and an outlet for discharge of small particles, (d) a first container in communication with the outlet for discharge of the large particles for collection of the large particles and (e) a second container in communication with the outlet for discharge of the small particles;
passing large particles and small particles into the sifting tray assembly;
injecting a cryogen at cryogenic temperature into the particle separation system to cool the plant stock to cryogenic temperatures to solidify the small particles, wherein, at least after injection, the cryogen comprises a gaseous cryogen;
operating the sifting tray assembly to separate the small particles from the large particles;
passing the large particles to the first container and passing the small particles to a second container; and
drawing the gaseous cryogen from the particle separation system with a first pump; and
operating the first pump to force the gaseous cryogen through a filter means to remove any small particles entrained in the gaseous cryogen drawn from the particle separation system.
2 . The method of claim 1 further comprising the step of:
operating the first pump to maintain vapor pressure within the particle separation system in the range of (1) a pressure substantially equal to ambient pressure to (2) a pressure 6895 Pa (1 psi/52 mmHg) less than ambient pressure.
3 . The method of claim 1 wherein:
the filter means comprises a bag filter, a cartridge filter, cyclone separator, a sedimenter, or an electronic precipitator.
4 . The method of claim 1 wherein:
the first container is a closed container with a first vent communicating from the first container to ambient atmosphere and the second container is a closed container with a second vent communicating from the second container to ambient atmosphere;
the first pump is disposed in the first vent; and
the particle separation system further comprises a second pump disposed in the second vent.
5 . The method of claim 1 wherein:
a first pump is disposed with a first pump inlet communicating with a large particle outlet aperture of the sifting tray and a first pump outlet communicating with the first container.
6 . The method of claim 1 wherein:
the first pump is disposed with a first pump inlet communicating with the small particle outlet aperture of the sifting tray and a first pump outlet communicating with the second container.
7 . The method of claim 1 , wherein:
the step of injecting a cryogen is accomplished by injecting cryogen at the inlet end of the sifting tray assembly; and
the step of drawing the gaseous cryogen from the particle separation system is accomplished by drawing gaseous cryogen through a port at the outlet end of the sifting tray assembly.
8 . The method of claim 1 , wherein plant stock is hops, and the method is used to separate lupulins from other components of hops.
9 . The method of claim 1 , wherein plant stock is salvia , and the method is used to separate essential oils from other components of salvia.
10 . The method of claim 1 , wherein plant stock is cannabis , and the method is used to separate trichomes from other components of cannabis.
11 . A method of separating small components from larger components of plant stock comprising, said method comprising:
providing a sifting system for separating small components from larger components of plant stock comprising;
a plurality of sifting tray assemblies, including at least a first sifting tray assembly and a second sifting tray assembly, wherein each sifting tray assembly comprises:
an upper enclosure with an inlet aperture located at a first, inlet end of the upper enclosure, and a large particle outlet aperture located at a second, outlet end of the upper enclosure;
a sifting screen below the upper enclosure
a cryogen injector disposed proximate the first end of the upper enclosure, said cryogen injector configured to supply a cryogenic fluid to plant stock entering the upper enclosure 6 ;
a bottom pan with a first end and a small particle outlet aperture located at a second end of the bottom pan, and a top open to the sifting screen, and a bottom with a closed surface;
wherein the sifting screen is disposed between the upper enclosure 6 and bottom pan;
a filter system in fluid communication with the sifting system, said filter system comprising:
a first pump for drawing cryogenic fluid from the sifting system;
a filter for filtering any small particles entrained in the cryogenic fluid drawn from the sifting system and forced through the filter by the first pump;
and performing the steps of:
depositing plant stock into a first sifting tray assembly, through the upper enclosure with an inlet aperture located at a first, inlet end; and
vibrating the first sifting tray assembly to (1) separate a first population of small particles from the larger particle of the plant stock in the first tray, and (2) cause or facilitate movement of the larger plant stock particles downwardly, over the sifting screen and within the upper enclosure and toward the large particle outlet aperture of the first sifting tray assembly, and (3) cause or facilitate movement of a first population of small particles downwardly within the pan bottom of the first sifting tray assembly toward the small particle outlet aperture of the first sifting tray assembly, and
spraying cryogen, using a cryogen injector of the first sifting tray assembly, over the plant stock within the first sifting tray assembly, or within the inlet or outlet tube of the first sifting tray assembly while vibrating and moving the stock toward the outlet apertures of the first sifting tray assembly,
passing the first population of small particles from the first sifting tray assembly to a second sifting tray assembly;
vibrating the second sifting tray assembly to (1) separate a second population of small particles from the first population of small particles in the second sifting tray assembly, and (2) cause or facilitate movement of the larger plant stock particles downwardly, over the sifting screen and within the upper enclosure and toward the large particle outlet aperture of the second sifting tray assembly, and (3) cause or facilitate movement of a second population of small particles downwardly within the bottom pan of the second sifting tray assembly toward the small particle outlet aperture of the second sifting tray assembly, and
spraying cryogen, using a cryogen injector of the second sifting tray assembly, over the plant stock within the second sifting tray assembly, or within the inlet or outlet tube of the second sifting tray assembly while vibrating and moving the stock toward the outlet apertures of the second sifting tray assembly,
passing the second population of small particles from the second sifting tray assembly;
drawing the gaseous cryogen from the sifting system with a first pump; and
operating the first pump to force the gaseous cryogen through the filter to remove any small particles entrained in the gaseous cryogen drawn from the sifting system.
12 . The method of claim 11 further comprising the steps of:
passing the separated small particles from a first sifting tray assembly through to the inlet of a second sifting tray assembly, and so on, for sifting operations through as many sifting tray assemblies as necessary to separate particles of the desired size, and collecting particles of the desired sized from a last small particle outlet aperture (if the last sift provides the desired small particles without unwanted smaller particles) or collecting particles of the desired sized from a last large particle outlet aperture (if the last sift provides the desired small particles in the upper enclosure and sifts undesired even smaller small particles through the sifting screen).
13 . The method of claim 11 , wherein plant stock is hops, and the method is used to separate lupulins from other components of hops.
14 . The method of claim 11 , wherein plant stock is salvia , and the method is used to separate essential oils from other components of salvia.
15 . The method of claim 11 , wherein plant stock is cannabis , and the method is used to separate trichomes from other components of cannabis.