Biochar apparatus and process
A biochar apparatus and a related biochar module may have a horizontal table-shaking mechanism and a tapered channel for causing biochar pieces generated in a firebox to fall through openings in the table to a conveyor system below. The table may be configured with replaceable grate panels. A quenching reservoir pan for holding quenching liquid receives a drainage basket at a discharge end of the conveyor system for quenching hot pieces of biochar and allowing easy retrieval of the quenched pieces.
1. An apparatus comprising:
a firebox for containing biomass to be burned to produce biochar;
a table arranged to support biomass contained in the firebox;
a conveyor system under the table, wherein the conveyor system comprises a conveyor drive motor, a drive pulley driven to rotate by the conveyor drive motor, an idler pulley spaced from the drive pulley, and a conveyor belt engaged by the drive pulley and the idler pulley;
a shaker mechanism connected to the table, wherein the shaker mechanism is operable to cyclically move the table in a horizontal plane relative to the firebox; and
a channel between the table and the conveyor system;
wherein the table includes a plurality of openings through which pieces of biochar pass to the conveyor system;
wherein the conveyor system is operable to convey the pieces of biochar and discharge the pieces of biochar from the conveyor system;
wherein the channel includes a tapered inner wall arranged to cover at least one of the drive pulley and the idler pulley and guide the pieces of biochar toward the conveyor belt.
2. The apparatus according to claim 1 , wherein the tapered inner wall of the channel includes a thermo-ceramic material.
3. The apparatus according to claim 1 , wherein the drive pulley is arranged at a discharge end of the conveyor system.
4. The apparatus according to claim 1 , wherein the table includes a table frame and a plurality of grate panels removably supportable by the table frame, wherein the plurality of grate panels includes the plurality of openings.
5. The apparatus according to claim 4 , wherein the plurality of grate panels includes grate panels having openings of a first size and grate panels having openings of a second size different from the first size, whereby a size of the pieces of biochar is controllable by choosing grate panels having openings of a desired size.
6. The apparatus according to claim 4 , wherein the table frame rests on a plurality of table support members that are fixed relative to the firebox.
7. The apparatus of claim 4 , wherein the shaker mechanism transmits a reciprocating horizontal stroke to the table frame in a longitudinal direction of the firebox.
8. The apparatus according to 7 , wherein the reciprocating horizontal stroke is in a range from one inch through two inches.
9. The apparatus according to claim 7 , wherein the shaker mechanism includes a shaker drive motor, a shaker drive shaft rotated by the shaker drive motor, a cam coupled to the shaker drive shaft, a follower engaged by the cam, and a transmission member arranged to transmit motion from the follower to the table frame, wherein the cam is eccentrically arranged with respect to a rotational axis of the shaker drive shaft.
10. The apparatus according to claim 7 , wherein the shaker mechanism includes a linear actuator connected to the table frame.
11. The apparatus according to claim 1 , further comprising a quenching reservoir pan adjacent a discharge end of the conveyor system, and a drainage basket removably received by the quenching reservoir pan, wherein the pieces of biochar are discharged from the conveyor system to the drainage basket and the quenching reservoir pan.
12. The apparatus according to claim 11 , wherein the drainage basket includes a pair of handles arranged on opposite sides of the drainage basket.
13. The apparatus according to claim 11 , wherein the quenching reservoir pan has a width corresponding to a width of the conveyor belt, and the drainage basket has a width dimensioned for close fit within the width of the quenching reservoir pan.
14. The apparatus according to claim 11 , wherein the quenching reservoir pan has a length greater than a length of the drainage basket.
15. The apparatus according to claim 1 , further comprising a chassis having a front end and a rear end, wherein the firebox is carried by the chassis, and the conveyor system is operable to convey the pieces of biochar to the rear end of the chassis and discharge the pieces of biochar from the conveyor system at the rear end of the chassis.
16. The apparatus according to claim 15 , wherein the rear end of the chassis includes a transverse gap for allowing the pieces of biochar to be discharged from the conveyor system.