JPH024103A - Particle quantity control method inside fluidized bed boiler - Google Patents

Abstract

PURPOSE:To facilitate the level control of particles in a particle storage tank by introducing air or gas adapted to control a separation performance of cyclone into the lower part of said cyclone which separates combustion gas and particles when it is necessary to control the quantity of particles inside a fluidized bed boiler. CONSTITUTION:A supply pipe 16 is installed to the lower part of a cyclone 5. The separation performance of the cyclone 5 is controlled by the air or gas supplied from the supply pipe 16. When the level L of articles e in a particle storage tank 7 rises, an increase in the introduction quantity of air or gas lowers the separation performance of the cyclone 5, increases the quantity of fine particles e' discharged from a cyclone outlet 9, and inhibits a rise in the level L of the particles e in the particle storage tank 7. When the level L drops, reduction in the supply of air or gas improves the separation performance of the cyclone 5 and reduces the quantity of the fine particles e' discharged from the cyclone outlet 9, thereby preventing the drop in the level L.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for adjusting the amount of particles in a fluidized bed boiler, which allows the level of particles in a particle storage tank to be easily adjusted.

[Conventional technology]

As shown in FIG. 2, in the conventional fluidized bed boiler, fuel a and supplementary solid matter are introduced into the combustion chamber 1 from the supply pipe 3, and air C is introduced from the fluidized bed nozzle 2 to perform combustion. Gas d and particles e are introduced into a cyclone 5 through a passage 4, and the cyclone 5 separates the combustion gas d and particles e.

The combustion gas d separated by the cyclone 5 flows into the dust collector 11 through the cyclone outlet 9 and the passage 10, and the dust collector 11 further separates the fine particles e' in the combustion gas d. "Only the particulate matter e is discharged from the particulate discharge port 13, and the particulate matter e.

The combustion gas d except for the combustion gas d is released from the passage 12.

On the other hand, particles e separated by cyclone 5 are
After passing through a cyclone particle outlet 6 at the bottom of the cyclone particle outlet 6 and being stored in a particle storage tank 7, the particles are returned to the combustion chamber 1 through a passage 8.

In this fluidized bed boiler, the level of particles e in the particle storage tank 7 is determined by the balance between the fuel a and the supplementary solids introduced into the combustion chamber 1, and the combustion gas d and particulates e' discharged from the cyclone outlet 9. Since L rises and falls, conventionally, the particles in the particle storage tank 7 are removed by extracting the particles e from the lower discharge port 14 or the upper discharge port 15, or by increasing the number of replenishing solid particles fed into the combustion chamber 1. level L of e
are being adjusted.

By the way, the particulates e″ discharged from the particulate discharge port 13
Since the particles are very small, they are easy to handle and process, and have utility value, whereas the upper discharge port 15
Also, coarse particles are mixed in the discharge from the lower discharge port 14, making it difficult to handle and dispose of, and also difficult to utilize.

Furthermore, when the level L of particles e drops, it is necessary to replenish an unnecessarily large amount of replenishing solid material, which is uneconomical.

[Problem to be solved by the invention]

The present invention has been made in order to solve the conventional problems as described above, and provides a method for adjusting the amount of particles in a fluidized bed boiler that can easily adjust the level of particles in a particle storage tank. The purpose is to

[Means to solve the problem]

The method for adjusting the amount of particles in a fluidized bed boiler of the present invention, which can achieve the above object, includes the following steps when adjusting the amount of particles in a fluidized bed boiler:
This method is characterized in that air or gas is introduced into the lower part of the cyclone that separates combustion gas and particles to adjust the separation performance of the cyclone.

〔Example〕

Hereinafter, the method of the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a schematic diagram of a fluidized bed boiler to which the method of the present invention is applied, and has substantially the same structure and function as the conventional example shown in FIG.

Therefore, description of the same parts as in the above description will be omitted, and the same parts in the figures are indicated by the same part numbers.

In the present invention, a supply pipe 16 is attached to the lower part of the cyclone 5, and the separation performance of the cyclone 5 is adjusted by air or gas supplied from the supply pipe 16.

That is, when the level L of particles e in the particle storage tank 7 increases, the amount of air or gas introduced is increased. As a result, the separation performance of the cyclone 5 decreases, the amount of fine particles e' discharged from the cyclone outlet 9 increases, and the particle storage tank 7
The increase in the level L of the particles e inside is suppressed.

Conversely, when the level L falls, the supply of air or gas is reduced. This improves the separation performance of the cyclone 5, reduces the amount of particulates e'' discharged from the cyclone outlet 9, and prevents the drop in level L mentioned above.

That is, according to the present invention, the separation performance of the cyclone 5 is adjusted by adjusting the amount of air or gas blown in by the flow rate regulating valve 17 disposed in the supply pipe 16, and the level of particles e in the particle storage tank 7 is adjusted. L can be easily adjusted.

The coarse particles contained in the particles e in the particle storage tank 7 become fine as they circulate through the passage 8 - the combustion chamber 1 - the passage 4 - the cyclone 5 -> the cyclone particle discharge port 6, and then the coarse particles are made fine as they circulate through the passage 8 - the combustion chamber 1 - the passage 4 - the cyclone particle discharge port 6 .
This makes it possible to discharge more easily.

Through experiments and studies, the present inventors have found that by blowing air or gas, for example, several percent of the amount of gas flowing into the cyclone 5 from the combustion chamber 1 through the supply pipe 16, the particulates e° discharged from the cyclone outlet 9 can be reduced. It has been confirmed that the amount can be changed several times.

〔Effect of the invention〕

As mentioned above, when adjusting the amount of particles in a fluidized bed boiler, the present invention introduces air or gas to the lower part of the cyclone that separates combustion gas and particles to adjust the separation performance of the cyclone. The level of particles in the particle reservoir can be easily adjusted.

Further, according to the present invention, there is no discharge of circulating particles including coarse particles that are difficult to process and have no utility value, and only fine particles that are easy to handle and have utility value are discharged.

Furthermore, when fuel and replenishment solids are introduced into the combustion chamber, the replenishment solid content is not increased unnecessarily, so that economical operation can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a fluidized bed boiler to which the method of the present invention is applied, and FIG. 2 is a schematic diagram of a conventional fluidized bed boiler. d... Combustion gas, e... Particles, 5... Cyclone, 11... Dust collector.

Claims (1)

[Claims] The amount of particles in a fluidized bed boiler is characterized in that when adjusting the amount of particles in the fluidized bed boiler, air or gas is introduced into the lower part of a cyclone that separates combustion gas and particles to adjust the separation performance of the cyclone. Adjustment method.