METHOD OF OPERATING A FIXED-BED GASIFIER FOR PRODUCING A PRODUCT GAS FROM POURABLE CARBONACEOUS PARTICLES

Abstract

A method of operating a fixed-bed gasifier includes positioning a tapping element at a first point above a bed of fuel particles, lowering the tapping element into the fuel particles along a first linear path to form a first linear passage in the fuel particles, raising the tapping element to retract the tapping element from the fuel particles along the first linear path so that the tapping element exits the fuel particles from the first linear passage, positioning the tapping element at a second point above the fuel particles, lowering the tapping element into the fuel particles along a second linear path to form a second linear passage in the fuel particles, and raising the tapping element to retract the tapping element from the fuel particles along the second linear path so that the tapping element exits the fuel particles from the second linear passage.

Claims

1. A method of operating a fixed-bed gasifier for producing a product gas from a bed of fuel particles, the method comprising the steps of: positioning at least one tapping element at a first point above the bed of fuel particles; lowering the at least one tapping element into the bed of fuel particles along a first linear path to form a first linear passage in the bed of fuel particles; raising the at least one tapping element to retract the at least one tapping element from the bed of fuel particles along the first linear path so that the at least one tapping element exits the bed of fuel particles from the first linear passage; positioning the at least one tapping element at a second point above the bed of fuel particles; lowering the at least one tapping element into the bed of fuel particles along a second linear path to form a second linear passage in the bed of fuel particles; and raising the at least one tapping element to retract the at least one tapping element from the bed of fuel particles along the second linear path so that the at least one tapping element exits the bed of fuel particles from the second linear passage, the at least one tapping element remaining axially fixed relative to the bed of fuel particles when being lowered and raised to minimize disturbance of fuel particles around the first linear passage and the second linear passage.

2. The method according to claim 1, wherein the at least one tapping element comprises a spike.

3. The method according to claim 2, wherein the spike is oriented vertically.

4. The method according to claim 2, wherein the at least one tapping element comprises a first tapping element with a first spike and a second tapping element with a second spike.

5. The method according to claim 4, wherein, when the first tapping element and the second tapping element are lowered into the bed of fuel particles, the first spike forms a first spike passage in the bed of fuel particles and the second spike forms a second spike passage in the bed of fuel particles.

6. The method according to claim 4, wherein the first spike and the second spike extend parallel to one another.

7. The method according to claim 1, wherein the at least one tapping element is centrally arranged relative to the bed of fuel particles.

8. The method according to claim 7, wherein the step of positioning the at least one tapping element at a second point above the bed of fuel particles comprises rotating the at least one tapping element in a horizontal plane above the bed of fuel particles.

9. The method according to claim 8, wherein the first point above the bed of fuel particles and the second point above the bed of fuel particles are located on a circular line.

10. The method according to claim 1, wherein the steps of lowering the at least one tapping element into the bed of fuel particles along a first linear path and lowering the at least one tapping element into the bed of fuel particles along a second linear path comprise lowering the at least one tapping element in a vertical direction so that the first linear passage and the second linear passage are vertical.

11. The method according to claim 1, wherein the steps of lowering the at least one tapping element into the bed of fuel particles along the first linear path and raising the at least one tapping element to retract the at least one tapping element from the bed of fuel particles along the first linear path are performed in reciprocating manner.

12. The method according to claim 1, wherein the at least one tapping element comprises a first tapping element on a first clinker device and a second tapping element on a second clinker device arranged side by side with the first clinker device.

Description

BRIEF DESCRIPTION OF THE DRAWING FIGURES

[0012] Further advantages and features of the present invention will be apparent from the following description with reference to the accompanying drawings. The following is shown:

[0013] FIG. 1a shows a schematic representation of a fixed-bed gasifier in a side view according to a first embodiment with a rotatable tapping element, wherein the tapping element is not inserted into the biomass;

[0014] FIG. 1b shows a schematic representation of the first embodiment, wherein the tapping element is inserted into a fuel-particle packed bed;

[0015] FIG. 2a shows a top view of a second embodiment with two clinker braking devices arranged side by side;

[0016] FIGS. 2b and 2c show side views of the second embodiment;

[0017] FIG. 3 shows a third embodiment;

[0018] FIG. 4 shows a fourth embodiment;

[0019] FIG. 5 shows a fifth embodiment; and

[0020] FIG. 6 shows a sixth embodiment of the invention.

DETAILED DESCRIPTION

[0021] FIG. 1a and FIG. 1b schematically show a first embodiment of a fixed-bed gasifier according to the present invention for generating a product gas from pourable carbonaceous fuel particles 1 in the form of biomass particles, particles of plastic or other carbonaceous fuel particles. The fixed-bed gasifier comprises a gasifier container 2 having a rectangular cross-section with side walls 4, an air supply 6 in the upper region of the gasifier 2, a fuel supply 8 opening laterally into the gasifier 2, a support device 10 for the fuel-particle packed bed in the form of a planar horizontally arranged grate 101, a product gas and ash drain 12 from the region below the grate 10, and a clinker braking device 14.

[0022] The clinker braking device 14 includes a tapping element 16 and a driving means 18. The driving means 18 includes a rotatable shaft 20 for rotating the tapping element in a horizontal plane and a vertical movement means 22 for linearly reciprocating the tapping element 16 in a vertical direction. The tapping element 16 includes a vertically oriented prong 24 mounted on one end of a flat crossbar 26. At its other end, the flat crossbar 26 is mounted to the rotatable shaft 20. A vertical movement means 22 may be designed, for example, as a double hydraulic cylinder. The rotatable shaft 20 is preferably rotated by an electric motor.

[0023] The rotatable shaft 20 with the tapping element 16 is arranged centrally in the gasifier 2 above the fixed bed of fuel particles 1. This embodiment allows only local points to be reached on a circular line. For small gasifiers with horizontal cross-sectional areas in the range from 10000 to 25600 mm.sup.2, this restriction is unproblematic. For even larger gasifier cross-sectional areas of 25600 to 42300 mm.sup.2, two or three prongs may be attached to the flat crossbar 26 instead of one prong 24. For even greater gasifier power and gasifier cross-sectional areas of 42300 mm.sup.2 and above, it makes sense to arrange two clinker braking devices 14 next to each other and operate them in parallel. For gasifier cross-sectional areas of 85000 mm.sup.2 and above, it makes sense to use two clinker braking devices 14 arranged next to each other with two or three prongs 24.

[0024] This use of two clinker braking devices 14-1 and 14-2 arranged side by side, as a second embodiment of the invention, is shown schematically in FIGS. 2a, 2b and 2c. FIG. 2a shows a top view of the open gasifier 2 with a rectangular cross-section with sides a and b, with a>b. In the rectangular gasifier cross-section 2, the two clinker braking devices 14-1 and 14-2 are shown. FIG. 2b shows the second embodiment in a view perpendicular to the view in FIG. 2a, and FIG. 2c shows the second embodiment in a view perpendicular to the views in FIGS. 2a and 2b.

[0025] FIG. 3 shows a third embodiment which differs from the first embodiment according to FIG. 1 in that a roller 102 rotating intermittently is provided as the support device 10 instead of the horizontal grate 101.

[0026] FIG. 4 shows a fourth embodiment, which differs from the third embodiment according to FIG. 3 in that two rollers 102 rotating intermittently with respect to each other are provided as the support device 10 instead of one roller.

[0027] The rollers 102 are provided with teeth 28 to crush present clinker lumps.

[0028] FIG. 5 shows a fifth embodiment, which differs from the first embodiment according to FIG. 1 in that instead of the horizontal grate 101, an inclined grate 103 is provided as the support device 10, as is known from DE 10 2018 205 115 A1.

[0029] FIG. 6 shows a sixth embodiment that differs from the first embodiment shown in FIG. 1 in that a tumbling cone crusher 104 is provided as a support device 10 instead of the horizontal grate 101.

[0030] During loading or start-up of the fixed-bed gasifier, the clinker braking devices 14 can also be used to distribute the fuel particles 1 in the gasifier by twisting the tapping elements 16 during filling of the fuel particles.