JPH05256437A - Secondary air supplying device for incinerator - Google Patents

Abstract

PURPOSE:To improve agitation and mixing of combustion gas and secondary air in an air supplying device for municipal dust incinerator by a method wherein an air supplying pipe having a plurality of air blowing ports is arranged along a pipe axis direction in such a manner that the air supplying pipe passes across a flow passage in a secondary combustion chamber and further the air supplying pipe is communicated with a blower. CONSTITUTION:A secondary combustion chamber 4 is provided with a plurality of air supplying pipes 8 across a flow passage of the secondary combustion chamber 4. The air supplying pipes 8 are formed with a plurality of air blowing ports 9 along its pipe axis direction. A secondary air blowing duct 10 is communicated with a base end of the air supplying pipe 8 and then the secondary air blowing duct 10 is connected to a secondary air blower secondary damper device. An extremity end of the air supplying pipe 8 is communicated with an air discharging duct through an air discharging duct 13. With such an arrangement, the secondary air is injected from the air blowing port 9 into the secondary combustion chamber 4, agitated and mixed as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary air supply device for an incinerator for suppressing the generation of dioxins in a municipal solid waste incinerator and a waste incinerator.

[0002]

2. Description of the Related Art In recent years, environmental pollution due to dioxins generated from municipal waste incinerators and waste incinerators has become a problem. The following factors are important for controlling these dioxins in the incinerator.

.. Maintain a high combustion gas temperature. ． Ensure a sufficiently long residence time of the combustion gas in the high temperature range. ． Good mixing of unburned gas and air in the combustion gas.

However, direct analysis of dioxins requires expensive analyzers and sophisticated techniques, and is not suitable for continuous analysis. For this reason, it is considered to monitor carbon monoxide (CO), which is a representative index of unburned gas and has a strong correlation with dioxins.

Conventionally, CO is provided in the middle of the flue of the incinerator.
A CO meter is provided, the CO concentration of the combustion exhaust gas is measured by the CO meter, and the combustion state of the incinerator is adjusted by feedback control such as adjusting the main combustion air amount and the secondary air amount based on the measured values for CO control. I was going.

[0006]

However, in the above-mentioned conventional structure, the secondary air is supplied to the combustion gas in the secondary combustion chamber, but the combustion gas is circulated in an upward flow. Therefore, the secondary air is not sufficiently agitated and mixed with the combustion gas, and C
There is a problem that the O concentration cannot be suppressed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a secondary air supply device for an incinerator capable of sufficiently agitating and mixing combustion gas and secondary air in a secondary combustion chamber. .

[0008]

In order to solve the above-mentioned problems, a secondary air supply device for an incinerator according to the present invention includes an air supply pipe which penetrates a secondary combustion chamber of the incinerator so as to cross a flow path. A plurality of air outlets are provided in the air supply pipe along the axial direction of the pipe, and an air blower is provided in communication with the air supply pipe.

[0009]

With the above structure, the combustion gas flows from the main combustion chamber of the incinerator into the secondary combustion chamber in an upward flow and is mixed with the secondary air ejected from the air outlet of the air supply pipe. At this time, the secondary air is ejected from a plurality of air outlets provided along the axial direction of the pipe while cooling the air supply pipe itself through the air supply pipe, so that the secondary air is generated in the air flow of the combustion gas. Mix evenly. Further, since the air supply pipe acts as a turbulent flow forming factor in the flow path of the secondary combustion chamber, the upward flow of the combustion gas becomes turbulent and becomes turbulent, and the turbulent flow sufficiently mixes and stirs the combustion gas and the secondary air. It Further, by supplying the surplus amount of the air supplied as the secondary air as part of the combustion air in the main combustion chamber of the incinerator, it is possible to suppress the excessive air supply.

Therefore, sufficient mixing and stirring of the secondary air and the combustion gas in the secondary combustion chamber can prevent the generation of CO and prevent the temperature of the atmosphere inside the furnace from being lowered due to incomplete combustion, thereby making it a precursor substance of dioxins. It suppresses the generation of dioxin and suppresses the generation of dioxins.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3, the incinerator 1 has a main combustion chamber 3 composed of a plurality of stages of combustion zones 2 and a secondary combustion chamber 4 formed above the main combustion chamber 3. Further, a blower duct 5 is opened below each combustion lag 2, and a combustion air blower 6 and a main damper device 7 are provided on the base end side of the blower duct 5. Further, damper devices 7a, 7b, 7c, 7d and 7e are provided in the middle of each air duct 5.

Then, as shown in FIG. 2, the secondary combustion chamber 4
Is provided with a plurality of air supply pipes 8 penetrating so as to cross the flow path of the secondary combustion chamber 4, and the air supply pipes 8 are provided with a plurality of air outlets 9 along the axial direction of the pipes. There is. In addition, a secondary blower duct 10 is provided so as to communicate with the base end side of the air supply pipe 8, and a secondary air blower 11 and a secondary damper device 12 are provided in the middle of the secondary blower duct 10. . Further, the tip end side of the air supply pipe 8 communicates with the blower duct 5 via the exhaust duct 13.

A CO concentration meter 15 is provided in the middle of the flue 14 continuing from the secondary combustion chamber 4.
5 is connected to the control device 16 via a signal line.
Further, the control device 16 includes a combustion blower 6 and a main damper device 7.
The damper devices 7a, 7b, 7c, 7d and 7e, the secondary air blower 11 and the secondary damper device 12 are connected to each other.

The operation of the above structure will be described below.
Combustion air is supplied to the main combustion chamber 3 from a combustion air blower 6 through a blower duct 5, and the combustion air is received to incinerate dust on each combustion zone 2. In addition, the combustion gas flows from the main combustion chamber 3 into the secondary combustion chamber 4 in an upward flow, and is ejected from the secondary blower 11 through the secondary blower duct 10 to be ejected from the air outlet 9 of the air supply pipe 8. It mixes with air and burns secondarily.

Further, a CO concentration meter 15 provided in the flue 14
CO concentration in the combustion exhaust gas was measured by
The combustion blower 6 is controlled by the controller 16 based on the value of the concentration.
And main damper device 7 and damper devices 7a, 7b, 7c, 7
d, 7e, the secondary air blower 11 and the secondary damper device 12 are appropriately controlled to control the amount of combustion air supplied from each blower duct 5 to the main combustion chamber 3 and the amount of secondary air blown out from the air supply pipe 8. adjust.

In the secondary combustion chamber 4, the secondary air passes through the air supply pipe 8 and cools the air supply pipe itself, and is ejected from a plurality of air outlets 9 provided along the axial direction of the pipe. Therefore, the secondary air is uniformly mixed in the flow of the combustion gas. Further, since the air supply pipe 8 acts as a turbulent flow forming factor in the flow path of the secondary combustion chamber 4, the upward flow of the combustion gas becomes turbulent and becomes turbulent flow, and the turbulent flow sufficiently mixes the combustion gas and the secondary air. Be stirred. Furthermore, by supplying the surplus amount of air supplied as the secondary air as a part of the combustion air in the main combustion chamber of the incinerator, it is possible to suppress the excessive air supply.

Therefore, sufficient mixing and stirring of the secondary air and the combustion gas in the secondary combustion chamber 4 prevents the generation of CO and prevents the temperature of the atmosphere inside the furnace from being lowered due to incomplete combustion, and the precursor of dioxins. It suppresses the generation of substances and suppresses the production of dioxins.

[0018]

As described above, according to the present invention, the secondary air is jetted from the plurality of air outlets provided along the axial direction of the air supply pipe, so that the secondary air is injected into the flow of the combustion gas. The secondary air can be uniformly mixed, and the combustion gas and the secondary air can be sufficiently mixed and stirred by the turbulent flow generated as a turbulent flow forming factor in the air supply pipe, and the secondary air in the secondary combustion chamber can be mixed. It is possible to prevent the generation of CO by sufficiently mixing and agitating the combustion gas, prevent the temperature of the atmosphere in the furnace from lowering due to incomplete combustion, and suppress the generation of precursor substances of dioxins to suppress the generation of dioxins. it can.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an incinerator according to an embodiment of the present invention.

FIG. 2 is an enlarged plan sectional view of a secondary combustion chamber in the same embodiment.

FIG. 3 is an enlarged vertical sectional view of a secondary combustion chamber in the same embodiment.

[Explanation of symbols]

 1 incinerator 3 main combustion chamber 4 secondary combustion chamber 7 main damper device 8 air supply pipe 9 air outlet

Claims (1)

[Claims] 1. A secondary combustion chamber of an incinerator is provided with an air supply pipe penetrating the secondary combustion chamber so as to cross a flow path, and a plurality of air outlets are provided in the air supply pipe along the axial direction of the pipe. A secondary air supply device for an incinerator, which is provided with an air blower in communication with the pipe.