JPH0697086B2 - Fluidized bed incinerator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a fluidized bed incinerator in which waste conveyed by a feeder is charged through a chute.

[Prior Art] A fluidized bed incinerator in which a fluidized medium, for example, sand is fluidized by an air flow, and incinerated matter, for example, waste such as municipal waste is put into incineration and incinerated, has high thermal efficiency and is widely used. It is used.

The control of the combustion speed in the conventional fluidized bed incinerator is performed by controlling the combustion air amount by the state after combustion, for example, the increase or decrease of the oxygen concentration in the exhaust gas, or by detecting the light of the combustion flame at the time of combustion to detect the secondary air amount. Was controlled by a method such as.

By the way, since the fluidized bed combustion furnace has a high combustion speed, the above-mentioned conventional method of controlling the amount of secondary air by capturing the result of combustion delays the response and the combustion is incomplete, and unburned gas is discharged. There is. Especially when a large amount of waste is input and supplied, unburned gas is easily discharged.

Generally, a technique for measuring the amount of dust supplied to an incinerator is known, and is described in, for example, Japanese Utility Model Laid-Open No. 58-191521. However, such known techniques cannot control the amount of air in a fluidized bed incinerator to maintain proper combustion.

[Problem to be solved] Therefore, an object of the present invention is to provide a fluidized bed incinerator capable of maintaining proper combustion without discharging unburned gas even if a large amount of waste is temporarily introduced.

[Means for Solving the Problems] According to the present invention, in a fluidized bed incinerator in which waste conveyed by a feeder is input through a chute, the waste is dropped and a collision plate is pivotally supported by the chute on the chute. Displacement angle detection means for movably supporting the displacement angle of the pivot shaft of the collision plate is provided, and load detection means for detecting a load based on a detection value of the displacement angle detection means is provided. Is connected to a controller having a timer, and the controller has a function of controlling first and second control valves provided in an air circuit connecting the air source and the freeboard.

Further, according to the present invention, the collision plate provided on the chute also serves as a flashback prevention damper.

[Operation] In the fluidized bed incinerator configured as described above, the displacement angle of the pivot shaft due to the impact of the load detection stage, for example, the weight of waste that is dropped and supplied to the load cell on the collision plate or the flashback prevention damper is determined. To detect through. When an abnormally large weight is detected, the controller opens the first control valve based on the detection signal and discharges a part of the flowing air to the freeboard. This reduces the amount of fluidizing air to the fluidized bed, slows the movement of the fluidized medium and slows the rate of gasification of the incinerator in the fluidized medium. At the same time, increase the opening of the second control valve to increase the amount of secondary air,
This prepares for an increase in the amount of unburned gas. At this time, the timing of the abnormal weight detection signal and the operation of both valves is adjusted by the controller. From these, the combustion speed can be controlled according to the input amount, a good combustion state can be obtained, and the generation of unburned gas can be prevented. The opening of the first control valve may be reduced without releasing a part of the flowing air to the freeboard.

[Preferred Embodiment] It is preferable that the rotation angle detecting means is composed of an L-shaped arm fixed to an end of a pivot shaft protruding outside the passage.

Further, it is preferable that the load detecting means is composed of a load cell provided between the L-shaped arm and the fixing member.

Further, it is preferable that the load cell is connected to a controller having a timer, and is connected to first and second control valves provided in the controller for the flow air source circuit and the secondary air source circuit.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the main body 1 of the fluidized bed incinerator is an air box 2,
The fluidized bed 3 and the freeboard 4 are provided, and between the air box 2 and the fluidized bed 3, an air dispersion plate 5 that distributes the fluidizing air from the air box 2 and guides it to the fluidized bed 3 is provided.

On the other hand, on the upper side of the main body 1, a feeder for conveying the waste A, that is, a screw feeder 7 in the illustrated embodiment is provided, and is connected to a chute 8 for throwing the waste A into the freeboard 6.

Further, the air chamber 2 is connected to the flow air source 9 by an air circuit L1, and the air circuit L2 branched from the circuit L1 is connected to the freeboard 4 via a first control valve V1 composed of, for example, a solenoid valve. ing. And free board 4
Is connected to the secondary air source 10 by a pneumatic circuit L3 via a second control valve V2 similar to valve V1.

A collision plate 11 is pivotally attached to the bent portion 8a of the chute 8 by a support shaft 12 at a position where the waste A collides.
One end of an L-shaped arm 13 which is a displacement angle detecting means shown in detail in FIG. 2 is fixed to the end of the support shaft 12 protruding from the bent portion 8a. And this arm
A lower end portion of a load cell 14, which is a load detecting means fixed to the bent portion 8a, is brought into contact with the upper surface of the other end of 13.

The load cell 14 is connected by an electric circuit 1 to a controller 15 equipped with a timer, and the controller 15 has a first and a second control valve connected by an electric circuit l2.
V1 and V2 are connected in parallel.

When the waste A dropped and supplied to the collision plate 11 collides during operation, the impact causes the support shaft 12 to rotate, and its displacement angle is transmitted to the load cell 14 via the arm 13 and the load cell 14
14 converts the displacement angle into weight and outputs it to the controller 15. The controller 15 outputs a control signal when the input weight value is abnormally large, and the first control valve V1
To open a part of the flowing air to the freeboard 4,
Reduce the flow air to slow the gasification rate of the incineration.
At the same time, the opening of the second control valve V2 is increased to increase the amount of secondary air to prepare for an increase in unburned gas. At this time, when the abnormal weight value is input and the first and second control valves
The timing with the operation of V1 and V2 is adjusted by the timer.

FIG. 3 shows another embodiment of the present invention, in which the collision plate provided on the upper end of the chute 8 also serves as a backfire prevention damper 11A according to a known technique. Others are the same as those in FIG. In this embodiment, the conventional flashback prevention damper can be modified and easily implemented.

[Effects of the Invention] As described above, the present invention has the following excellent effects.

(I) Since the collision plate is provided on the chute, it is possible to detect when waste is supplied from the feeder to the chute,
Control can be performed quickly.

(Ii) Since the amount of air to the freeboard is controlled to increase when the amount of waste is large, a good combustion state can be maintained.

(Iii) It is possible to cope with a rapid increase in waste in a fluidized bed incinerator, to obtain an incinerator with a small amount of unburned components and high efficiency.

(IV) It can be carried out by using a known flashback prevention damper, and improvement is easy.

[Brief description of drawings]

1 and 2 are an overall configuration diagram showing an embodiment of the present invention and a side cross-sectional view of an essential part, and FIG. 3 is a drawing corresponding to FIG. 2 showing another embodiment of the present invention. 3 ... Fluidized bed, 7 ... Screw feeder, 8 ... Chute, 9 ... Fluidizing air source, 10 ... Secondary air source, 11 ...
Collision plate, 11A ... Damper for flashback prevention, 12 ... Spindle, 13 ...
… Arm, 14… load cell

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Keiichi Sato 11-11 Haneda-Asahi-cho, Ota-ku, Tokyo Ebara Corporation (56) References

Claims (2)

[Claims] 1. In a fluidized bed incinerator in which waste conveyed by a feeder is introduced through a chute, a collision plate is pivotally supported by a pivot shaft on the chute into which the waste is dropped, Displacement angle detection means for detecting the displacement angle of the pivot shaft of the collision plate is provided, and load detection means for detecting the load based on the detection value of the displacement angle detection means is provided, and the load detection means is a controller equipped with a timer. A fluidized bed incinerator, which is connected and has a function of controlling first and second control valves provided in an air circuit connecting an air source and a freeboard. 2. The fluidized bed incinerator according to claim 1, wherein the flashback prevention damper provided in the passage also serves as a collision plate.