JP2002310416A - Refuse incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refuse incinerator wherein a combustion state in a secondary combustion chamber is easily stabilized. SOLUTION: Gas generated by after-combustion of refuse, which has been subjected to primary combustion in a primary combustion chamber is extracted to the outside of a furnace body 2 from an after-combustion zone and injected in a secondary combustion chamber. By irradiating gas, generated by after- combustion, with a laser beam by a laser detecting meter 10 through a measuring window 12 formed in a furnace body 2, oxygen concentration of the gas generated by the after-combustion is detected. A control means 17 is provided to control a primary combustion air feed device 5 based on the detecting result of the laser detecting meter 10 so that the oxygen concentration of the gas generated by the after-combustion is adjusted to a target concentration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is constructed so that gas generated by post-combustion of refuse mainly burned in a primary combustion chamber is extracted from a post-combustion zone to the outside of a furnace body and injected into a secondary combustion chamber. Regarding refuse incinerators.

[0002]

2. Description of the Related Art In the post-combustion zone on the post-combustion stoker side, unburned residues in the incineration ash sent from the combustion stoker are burned. Therefore, oxygen is not consumed much, and the gas generated by the post-combustion has a relatively high oxygen concentration.

Therefore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 7-332627, a high temperature
The gas having a high oxygen concentration is extracted out of the furnace body and injected into the secondary combustion chamber, whereby the gas is mixed with the gas in the secondary combustion chamber and stirred to promote the secondary combustion.

Conventionally, in the above-mentioned refuse incinerator, the primary combustion air supply device is controlled by a control device so that the supply amount of the primary combustion air can be changed and adjusted. The structure was such that the oxygen concentration was likely to fluctuate (generally, an excessive amount of air was supplied to the post-combustion stage).

[0005]

According to the above conventional construction, the oxygen concentration in the gas generated by the post-combustion, that is, the gas extracted outside the furnace main body and injected into the secondary combustion chamber is liable to fluctuate. Due to the structure, the combustion state in the secondary combustion chamber may become unstable, leaving room for improvement.

An object of the present invention is to provide a refuse incinerator that can easily stabilize a combustion state in a secondary combustion chamber.

[0007]

The constitution, operation and effect of the invention according to claim 1 are as follows.

In the refuse incinerator described at the beginning, the gas generated by the post-combustion is irradiated with laser light by a laser detector through a measurement window formed in the furnace main body, so that the oxygen of the gas generated by the post-combustion is reduced. Control means is provided for detecting the concentration and controlling the primary combustion air supply device based on the detection result of the laser detector so that the oxygen concentration of the gas generated by the post-combustion becomes the target concentration.

[A] [A] A laser detector irradiates a laser beam through a measurement window formed in the furnace body with a laser detector to detect the oxygen concentration of the gas.

For example, detection is performed as follows.

Structure: A laser beam generated from a semiconductor laser transmitter is guided to a laser projector by an optical fiber, irradiated into a furnace, and a residual laser beam intensity is detected by a laser detector.

Principle (Spectral absorption method) Each component in a gas has a specific absorption wavelength with respect to an infrared laser. When the laser light passes through the measurement gas body, a certain component (eg, oxygen) in the gas absorbs the laser light of a specific wavelength, and the amount of the absorbed laser light is proportional to the gas concentration. By detecting the amount of the absorbed specific wavelength laser light, the concentration of the specific component (eg, oxygen) in the gas can be converted.

[B] Based on the detection result of the laser detector, the primary combustion air supply device is controlled by the control means.
For example, the supply amount of the primary combustion air and the preheating temperature of the primary combustion air are changed and adjusted, and the oxygen concentration of the gas generated by the post-combustion is set to the target concentration.

[C] The gas generated by the post-combustion is a gas that is extracted outside the furnace body and injected into the secondary combustion chamber, and the oxygen concentration in this gas can be set to the target concentration. If the target concentration is set to be constant, a gas having a constant oxygen concentration can be injected into the secondary combustion chamber.

[4] The oxygen concentration is detected by irradiating the gas generated by the post-combustion gas with laser light by a laser detector through a measurement window formed in the furnace main body. Unlike the means for detecting the oxygen concentration after removal, the oxygen concentration can be detected in real time.

As a result, when the combustion state in the furnace fluctuates, the primary combustion air supply device is controlled in accordance with the fluctuation, and the oxygen concentration of the gas generated by the post-combustion can be immediately set to the target concentration. .

[Effects] Therefore, the above operations [A],
According to [b], [c] and [d], a refuse incinerator that can easily stabilize the combustion state in the secondary combustion chamber could be provided.

[0018]

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

1 and 2 show a refuse incinerator. In this refuse incinerator, a stoker 3 for burning refuse from a hopper 1 is provided in a furnace main body 2 to form a combustion chamber 4 composed of a primary combustion chamber 4A and a secondary combustion chamber 4B. A primary combustion air supply device 5 for supplying the combustion chamber 4A, a secondary combustion air supply device 6 for supplying the secondary combustion air to the secondary combustion chamber 4B, and a post-combustion gas supply means 16 for the secondary combustion chamber 4B, which will be described later. And an ash discharge port 7 for discharging incinerated ash after combustion.

The stoker 3 is composed of a drying stoker 3A, a combustion stoker 3B, and a post-combustion stoker 3C. 3B, 3C
Is connected to the lower side of the.

The drying zone 21 on the side of the drying stoker 3A
The supply amount of the primary combustion air to the combustion zone 22 on the combustion stoker 3B side and the post-combustion zone 23 on the post-combustion stoker 3C side are respectively different (combustion zone 22).
Supply is the largest).

The refuse introduced into the hopper 1 includes a dry stoker 3A, a burning stoker 3B, and a post-burning stoker 3C.
And the primary combustion by the primary combustion air.

The drying zone 21 on the side of the drying stoker 3A
In this case, the high-temperature combustion gas generated by the combustion in the subsequent combustion zone 22 and the post-combustion zone 23 mainly dries the refuse and starts partial combustion.

The combustion zone 22 on the combustion stoker 3B side
In this case, refuse is mainly burned by the primary combustion air.

In the post-combustion zone 23 of the post-combustion stoker 3C, the unburned residue in the incineration ash sent from the combustion zone 22 is burned. Therefore, oxygen is not consumed much, and the gas in the post-combustion zone 23 generated by post-combustion has a relatively high oxygen concentration.

Therefore, a high-temperature, high-oxygen-concentration gas is extracted from the post-combustion zone 23 to the outside of the furnace main body 2 by the post-combustion gas supply means 16 and is injected into the secondary combustion chamber 4B.
Thereby, the gas is mixed with the gas in the secondary combustion chamber 4B and stirred to promote the secondary combustion.

That is, the post-combustion gas supply means 16 comprises:
The gas extraction port 2 is provided on the ceiling wall of the furnace body 2 on the post-combustion zone 23 side.
6, the gas extraction port 26 and the side wall 2 of the furnace body 2 are formed.
The plurality of gas supply ports 24 are connected to each other through a gas line 18, and a heat exchanger 27 and a blower 28 are provided in the gas line 18. The heat exchanger 27 cools the gas. 1 and 2, reference numeral 9 denotes an air supply pipe of the secondary combustion air supply device 6.

A measurement window 12 is formed in the furnace main body on the side corresponding to the post-combustion zone 23.
By irradiating the gas generated by the post-combustion with a laser beam through the laser detector 10 through (see FIG. 3), the oxygen concentration and the gas temperature of the gas generated by the post-combustion are detected. Target density (for example, 15
%), A controller 17 (corresponding to control means) for controlling the blower 30 of the primary combustion air supply device 5 based on the detection result of the laser detector 10 is provided.

As shown in FIG. 3, the measuring window 12 is formed by forming two openings on the side wall 2A of the furnace main body 2 on the laser transmitting side and the receiving side so as to face the laser beam directly. Irradiation is performed inside the furnace.

As shown in FIGS. 2 and 3, the laser detector 10 includes a detection main body 20 having a laser light source and a measurement window 1.
2 is connected to the optical fiber cable 15 via the signal processor 41, and is connected to the control device 17 (corresponding to control means).
In FIG. 7, various operations can be executed.

The laser detector 10 detects the oxygen concentration and the gas temperature as follows.

The laser transmitter 31 generates a laser beam while scanning the wavelength. The laser beam is adjusted to a constant beam diameter by the laser projection device 14 and then directly radiated into the furnace, passes through the gas body in the furnace, and at the same time, a laser beam of a specific wavelength is absorbed by a certain component in the gas. The laser detector 1 installed on the opposite side of the laser projection device 14
At 4 ′, the intensity of the remaining laser beam is measured, and the signal processor 41 obtains the amount of the gas component corresponding to the specific absorbed wavelength.

Since the oxygen concentration and the gas temperature are detected and detected by the laser detector 10 as described above, they can be detected in real time.

If the oxygen concentration of the gas detected by the laser detector 10 is not at the target concentration, the controller 17 controls the blower 30 of the primary combustion air supply device 6 to change and adjust the supply amount of the primary combustion air. The oxygen concentration of the gas generated by the post combustion is set to the target concentration (for example, 15%).

The oxygen concentration is detected by irradiating the post-combustion zone 23 with laser light by the laser detector 10 through the measurement window 12 formed in the furnace main body 2. 2, the oxygen concentration can be detected in real time, unlike the means for taking the sample outside and detecting the oxygen concentration.

[Another Embodiment] The control device 17 may be configured to control the air preheater of the primary combustion air supply device 5.

The number of the measurement windows 12 is not limited to the number in the above embodiment, but may be plural, for example.

The post-combustion gas supply means 16 is configured to mix outside gas (air) with the gas extracted from the post-combustion zone 23 (gas generated by post-combustion) and to inject it into the secondary combustion chamber 4B. You may.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a combustion furnace.

FIG. 2 is a front view of a combustion furnace.

FIG. 3 shows a heat-resistant probe.

[Explanation of symbols]

 2 Furnace body 4A Primary combustion chamber 4B Secondary combustion chamber 6 Primary combustion air supply device 10 Laser detector 12 Measurement window 17 Control means 23 After combustion zone

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shizuo Kataoka 2-33 Kingara-cho, Amagasaki-shi, Hyogo F-term in Takuma Co., Ltd. (Reference) 3K062 AA02 AB01 AC01 BA02 CA06 DA22 DB06 3K078 BA03 CA03 CA06 CA12

Claims (1)

[Claims] 1. A refuse incinerator configured to extract gas generated by post-combustion of refuse mainly combusted in a primary combustion chamber from a post-combustion zone to the outside of a furnace body and to inject it into a secondary combustion chamber. Irradiating a laser beam to the gas generated by the post-combustion with a laser detector through a measurement window formed in the furnace body to detect the oxygen concentration of the gas generated by the post-combustion; A refuse incinerator provided with control means for controlling the primary combustion air supply device based on the detection result of the laser detector so that the oxygen concentration of the fuel cell reaches the target concentration.