Patent ID: 7976259
Filing Date: 2011-07-12
Classification: B01J,B65G,C10J,C10L,C12M,Y02E,Y02P

Abstract:
1. A system for feeding biomass into a pressured vessel, the system comprising: a screw-feeding housing; a drive motor attached to the screw-feeding housing; a rotary airlock valve attached to the screw-feeding housing, wherein the rotary airlock valve has an inlet port for receiving biomass material and an outlet port for disposing biomass material into the interior of the screw-feeding housing and wherein the rotary airlock valve substantially impedes airflow between the interior of the screw-feeding housing and the inlet port; a first conveyor screw disposed within the screw-feeding housing for receiving biomass material from the outlet port of the rotary airlock valve and conveying biomass material through the screw-feeding housing, wherein the first conveyor screw is double flighted and has a diameter; a second conveyor screw disposed within the screw-feeding housing and attached to the first conveyor screw, wherein the second conveyor screw has a diameter smaller than the diameter of the first conveyor screw and wherein the second conveyor screw has a bare shaft; a barrel disposed within the screw-feeding housing, wherein the second conveyor screw and a portion of the first conveyor screw are disposed within the barrel and wherein the barrel receives biomass material from the first conveyor screw and the second conveyor screw; a low friction liner attached to a substantial portion of the inside surface of the barrel, wherein the length of the low friction liner is shorter than the length of the barrel; a pressure sensor positioned within the screw-feeding housing for monitoring backpressure; a compression disk position at the outlet of the barrel for compressing biomass material before the material falls from the outlet of the barrel into the pressurized vessel, thereby forming a biomass plug at the outlet of the barrel; an actuator connected to the compression disk, wherein the actuator imposes a translational force upon the compression disk; a function controller which controls the pressure sensor, the drive motor and the actuator; and a control loop which comprises the function controller, the actuator, the drive motor, and the pressure sensor for monitoring backpressure within the screw-feeding housing and for controlling and adjusting the force applied by the actuator to the compression disk and the torque applied by the drive motor to the first conveyor screw, thereby effectuating an effectively sealed biomass plug.