Decortication system and process

Abstract

A decortication system includes a feeder configured to convey unoriented fiber-bearing plant stalks in a bulk mass and a decorticator assembly comprising a multi-stage decorticator assembly. The decorticator assembly includes at least a first stage decorticator and a second stage decorticator arranged in series with one another. The first stage decorticator comprises a ripper that is configured to separate stalks from the bulk mass delivered by the feeder and to meter movement of stalks away from the ripper. The second stage decorticator is located downstream of the ripper and further decorticates the stalks to produce fiber and hurd that are separated from one another. It may comprise a roller-roller breaker assembly comprising plurality of roller-breaker assemblies located in series with one another. A third stage decorticator may be located downstream of the second stage decorticator and may comprise a second roller-breaker assembly.

I claim: 
     
         1 . A decortication system comprising:
 at least first and second stage decorticators located in series, the first stage decorticator comprising a ripper that configured to separate stalks from a bulk mass of unoriented fiber-bearing plants, to meter movement of stalks away from the ripper, and to partially decorticate the stalks, the second stage decorticator being located downstream from the first stage decorticator and being configured to further decorticate the stalks.   
     
     
         2 . The decortication system as recited in  claim 1 , further comprising a feeder that is configured to convey the mass of bulk unoriented stalks to the first stage decorticator. 
     
     
         3 . The decortication system as recited in  claim 2 , wherein the feeder comprises a feed conveyor assembly that comprises first and second laterally spaced, longitudinally extending conveyors capable of collectively transporting bales of unoriented stalks. 
     
     
         4 . The decortication system as recited in  claim 2 , further comprising a driven accumulator that delivers bales to the feeder one at a time. 
     
     
         5 . The decortication system as recited in  claim 1 , wherein the ripper comprises a vertically extending endless belt having an outer surface and laterally and longitudinally spaced protrusions that extend outwardly from the outer surface of the belt. 
     
     
         6 . The decortication system as recited in  claim 1 , further comprising an air curtain generator located between the ripper and the second stage decorticator, the air curtain generator comprising a blower that blows stalks from the air curtain to the second stage decorticator while allowing denser objects to fall short of the second stage decorticator. 
     
     
         7 . The decortication system as recited in  claim 1 , wherein the second stage decorticator comprises a roller-breaker assembly including a plurality of roller sets located in series with one another, wherein each of the roller sets has first and second spaced rotating rollers having a nip formed therebetween through which stalks are drawn. 
     
     
         8 . The decortication system as recited in  claim 7 , further comprising a third stage decorticator located downstream from the second stage decorticator, the third stage decorticator comprising a second roller-breaker assembly including a plurality of roller sets arranged in series with one another. 
     
     
         9 . The decortication system as recited in  claim 8 , wherein the first roller-breaker assembly comprises at least two roller sets. 
     
     
         10 . The decortication system as recited in  claim 9 , wherein the first roller-breaker assembly further comprises at least one whipper that is located in series with the roller sets, the whipper having a rotating core and a plurality of flexible straps that extend outwardly from the rotating core and that are spaced axially and circumferentially of one another about the core. 
     
     
         11 . The decortication system as recited in  claim 8 , wherein the second roller-breaker assembly comprises at least six roller sets. 
     
     
         12 . The decortication system as recited in  claim 11 , wherein the second roller-breaker assembly comprises at least twelve roller sets. 
     
     
         13 . The decortication system as recited in  claim 7 , further comprising variable frequency drives, each of which is configured to adjust a rotational speed of at least one roller set independently of at least one other roller set. 
     
     
         14 . The decortication system as recited in  claim 7 , wherein nips of a plurality of upstream-most roller sets decrease in diameter from the upstream-most roller set of the plurality to the downstream-most roller set of the plurality. 
     
     
         15 . The decortication system as recited in  claim 7 , further comprising a tensioning device that is configured to press the first and second rollers of each roller set together with an adjustable down pressure. 
     
     
         16 . The decortication system as recited in  claim 7 , wherein the second stage decorticator comprises a frame having upper and lower sections on which the upper and lower rollers of each roller set are independently and removably mounted. 
     
     
         17 . The decortication system as recited in  claim 16 , further comprising a powered actuator assembly that is configured to raise and lower the upper section of the frame relative to the lower section of the frame. 
     
     
         18 . The decortication system as recited in  claim 1 , further comprising a screen assembly that is located downstream from the second stage decorticator and that is configured to further separate fiber from hurd. 
     
     
         19 . The decortication system as recited in  claim 18 , wherein the screen comprises at least one trammel screen. 
     
     
         20 . The decortication system as recited in  claim 1 , further comprising a wheeled trailer on which the feeder and the first and second stage decorticators are mounted for transport as a unit. 
     
     
         21 . A decortication system comprising:
 (A) a mobile trailer having ground engaging wheels;   (B) a feeder configured to convey unoriented fiber-bearing plant stalks in a bulk mass;   (C) a first stage decorticator that is mounted on the trailer, the first stage decorticator comprising a ripper located adjacent a downstream end of the feeder, the ripper being configured to separate stalks from the mass and to meter movement of stalks away from the ripper and to partially decorticate the stalks;   (D) a second stage decorticator that is mounted on the trailer downstream of the first stage decorticator in the direction of stalk movement through the system, the second stage decorticator comprising a roller-breaker assembly formed from a plurality of roller sets, each comprising first and second toothed rollers having a nip formed therebetween; and   (E) an air curtain generator that is mounted on the trailer between the first and second stage decorticator, the air curtain generator being configured to generate an air stream of sufficient force to blow stalks toward the second stage decorticator from the first stage decorticator.   
     
     
         22 . The decortication system as recited in  claim 21 , further comprising a third stage decorticator that is mounted on the trailer downstream of the second stage decorticator in the direction of stalk movement through the system, the third stage decorticator comprising a roller-breaker assembly formed from a plurality of roller sets, each comprising first and second toothed rollers having a nip formed therebetween, and further comprising a conveyor located between second and third stage decorticators. 
     
     
         23 . A method comprising:
 (A) separating stalks from a bulk mass of unoriented stalks and conveying the separated stalks away from the bulk mass at a controlled volumetric rate; and   (B) decorticating the separated stalks to produce fiber and hurd that are separated from one another.   
     
     
         24 . The method as recited in  claim 23 , wherein the separating step is performed by an endless belt having protrusions extending from an outer surface thereof that strip stalks from the bulk mass, and wherein the belt performs a portion of the decorticating step. 
     
     
         25 . The method as recited in  claim 24 , further comprising passing the separated stalks though an air curtain that blows stalks to a downstream decorticator stage while allowing dense objects to fall short of the downstream decorticator stage. 
     
     
         26 . The method as recited in  claim 23 , wherein the bulk mass comprises a bale weighing at least 500 lbs. 
     
     
         27 . The method as recited in  claim 23 , wherein the separating and decorticating steps are performed at a rate of at least 5 tons per hour. 
     
     
         28 . The method as recited in  claim 23 , wherein at least 50% of the separated hurd is at least 0.5″ long. 
     
     
         29 . The method as recited in  claim 23 , wherein the decorticating step is performed in at least two sequential stages, with the first stage being performed by a ripper that also performs the separating step and the second stage being performed by a roller-breaker assembly formed from a plurality of roller sets, each of which has first and second spaced rotating rollers having a nip formed therebetween through which stalks pass. 
     
     
         30 . The method as recited in  claim 29 , wherein the second stage is performed by a first roller-breaker assembly, and further comprising performing a third stage of decortication using a second roller-breaker assembly located downstream from the first roller-breaker decorticator assembly. 
     
     
         31 . The method as recited in  claim 30 , further comprising setting a rotational speed of the rollers of at least one roller set independently of the rollers of at least one other roller set. 
     
     
         32 . The method as recited in  claim 31 , wherein speeds of a plurality of upstream-most roller sets increase progressively from the upstream-most roller set of the plurality to the downstream-most roller set of the plurality, thereby progressively orienting unoriented stalks passing therethrough. 
     
     
         33 . The method as recited in  claim 29 , further comprising, in order to accommodate varying stalk characteristics, at least one of 1) adding additional roller sets to the roller-breaker decorticator, 2) removing roller sets from the roller-breaker decorticator, and 3) replacing rollers of roller sets having rollers of a first profile with roller sets of a second profile.