JPS601285A - Control of fluid layer height in coal gasifying oven - Google Patents

Abstract

PURPOSE:To control heights of fluid layers and gasify coal with a high efficiency, by adjusting difference in pressure between a gasification zone and a combustion zone. CONSTITUTION:In a gasifying oven 1 which is divided by partition walls 2A and 2B in the shape of concentric circles into a gasification zone 3 and a combustion zone 4, raw material coal and steam are fed through a pipe 8 and a pipe 9, respectively, into the zone 3 for gasification. Then coal particles are sent via a transit layer zone 10 to the zone 4 and are made to ascend for combustion by air supplied through a pipe 11. They are circulated to the zone 3 via an overflow zone 13. Produced gas is taken out through a pipe 5 and combustion gas and ash are discharged through a pipe 6 and a pipe 14, respectively. In the above system, valves 5A and 6A are controlled to adjust difference in pressure between the zones 3 and 4 (7 is a differential pressure gauge) and heights of fluid layers. Consequently amt. of circulation of particles passing through the overflow zone 13 and gas mixing ratio are controlled.

Description

Detailed Description of the Invention The present invention provides a coal gasification system in which the inside of the gasifier main body is separated into fluidized beds of a gasification section zone and a combustion section zone by a partition wall provided concentrically with the gasifier main body. The present invention relates to a method for controlling the bed height level of each fluidized bed in a furnace.

In recent years, there has been an urgent need to effectively utilize coal in order to diversify energy resources. Among these, a fluidized bed method is usually adopted in a high-calorie gasification process in which coal is gasified to obtain raw material gas or fuel gas. Oxygen and steam are used as gasifying agents in high-calorie gasification processes, but in recent years, coal gas has been separated into two fluidized beds by separating the tower reactor (gasification, furnace body) into two fluidized beds using concentric partition walls. A chemical furnace has been proposed. In this coal gasifier, steam is supplied to the outside of the partition wall and the coal or char is transferred to the first fluidized bed (
gasification zone). The unreacted char produced in the first fluidized bed is sent to the second fluidized bed (combustion zone) inside the partition wall, where some carbon is combusted and simultaneously transported to the upper part of the reactor. The particles heated by combustion in the air in the combustion zone are returned to the gasification zone and are used as a heat source in the gasification zone.

A coal gasifier that is separated into a gasification zone and a combustion zone has the advantage of being able to gasify gas by using air instead of oxygen.

However, in order to perform efficient coal gasification by controlling the amount of particle circulation and the gas mixture rate between the two fluidized beds, it is necessary to control the bed height of each fluidized bed in the gasification zone and combustion zone. is necessary. Conventionally, the method of controlling the height of the fluidized bed was to control only the height of the fluidized bed in the gasification zone by the amount of char supplied or the amount of ash discharged; It was considered impossible to control them independently.

An object of the present invention is to provide a coal gasifier that is separated into two fluidized beds, a gasification zone and a combustion zone, by a gasifier body and a concentric partition wall, and to increase the bed height of each of the two fluidized beds. An object of the present invention is to provide a high-level control method for a coal gasifier that can be controlled.

The present invention controls the bed height of each of the two fluidized beds by controlling the differential pressure between the gasifier zone and the combustion zone to control the particle circulation G%nT or gas entrainment rate. This is what I did.

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

In FIG. 1, a gasifier main body 1 is provided with two partition walls arranged concentrically on the main body, and the upper ends of the two partition walls are arranged concentrically around the gasifier main body 1 so that their lower ends are located at six intervals. A partition wall 2B is provided in a shape. Therefore, the first
In the figure, the outside of the two partition walls forms a gasification section zone 3, and the inside of the partition wall 2 forms a combustion section zone 4.

Further, control valves 5A and 6A are provided at the produced gas outlet pipe 5 and the combustion gas outlet -W6, respectively, and a differential pressure gauge 7 for measuring the pressure difference between the Okayama outlet pipes 5 and 6 is attached.

In such a coal gasifier, coal or char particles to be gasified are supplied to the gasifier zone 3 in the gasifier main body i through the raw material supply pipe 8.

In the gasifier zone 3, the coal is fluidized by the steam supplied from the steam common supply pipe 9 and gasified.

The particles reacted in the gasification section C/3 pass through the moving bed section 10 and enter the combustion section zone 4.

In the combustion section zone 4, a part of the carbon is combusted by the air introduced through the air supply pipe 11, and the particles are heated and simultaneously transported to the empty tower section 12 above the combustion section zone 4. These high-temperature particles are returned to the gasification section zone 3 again through an overflow section 13 consisting of a gap formed by the two partition walls and the partition wall 2B, and are used as a heat source in the gasification section zone 3. The combustion exhaust gas generated in the combustion section zone 4 is exhausted to the outside of the system through the combustion gas outlet pipe 6. The produced gas produced in the gasification section zone 3 is exhausted from the produced gas outlet pipe 5, while the ash produced within the system is discharged from the system from the ash outlet pipe 14.

In this way, since the combustion gas and the produced gas are taken out from the two systems while circulating the char particles from the combustion section zone 4 to the gasification section zone 3, the amount of particle circulation or the amount of gas mixed in via the overflow section 13 is controlled. There must be.

In this embodiment, when the combustion gas outlet pipe 60 control valve 6A is throttled to increase the pressure in the combustion section zone 4, the layer height level in the gasification section zone 3 increases, and the amount of particles circulating through the overflow section 13 decreases. do. On the other hand, when the control valve 5A of the produced gas outlet pipe 50 is throttled to increase the pressure in the gasification section zone 3, the bed height level of the combustion section zone 4 rises and the bed height level of the gasification section zone 3 falls. Therefore, the pressure difference between the gasification section zone 3 and the combustion section zone 4 by operating the control valve 5A16A can be measured by the differential pressure gauge 7, and the layer height level of each seam can be controlled.

As described above, according to the present invention, the gasification zone (endothermic reaction) and combustion zone (exothermic reaction) in a coal gasifier
The bed height of each reaction zone can be controlled by controlling the pressure in each zone, and the particle amount it and the amount of gas mixed in can be controlled, so that efficient coal gasification can be performed.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. 1... Gasifier main body, 2 people, 2B... partition wall, 3.
... Gasification zone, 4... Combustion zone, 5...
Generated gas outlet pipe, 6... Combustion gas outlet pipe, 5A', 6
A... Control valve, 7... Differential pressure gauge, 8... Raw material supply pipe, 9... Steam supply pipe, 10... Moving bed section,
11... Air supply pipe, 12... Sky tower section, 13...
・Overflow part, 14...ash outlet pipe. Agent Tatsu Unuma 2 Figure 1 6Δ

Claims (1)

[Claims] (1) A coal gasifier in which the gasifier main body is separated into fluidized beds of a gasification zone and a combustion furnace zone by a partition wall provided concentrically with the gasifier main body. A method for adjusting a bed height level in a coal gasifier, comprising controlling the level of each fluidized bed by adjusting the differential pressure between the gasification zone and the combustion zone.