JP2011094869A - Method of operating fluidized bed type incinerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of operating a fluidized bed type incinerator capable of improving combustion efficiency of fuel gas within the fluidized bed. <P>SOLUTION: In the method of operating the fluidized bed type incinerator, the fluidized bed 21 is formed in the lower part within an incinerator body 1, and an air diffusion means 3 diffusing flowing air for flowing and stirring the fluidized bed 21 and an incinerated object mixed within the fluidized bed 21 is provided in the lower part within the fluidized bed 21. A combustion means 4 jetting fuel gas with which primary air is mixed and burning the fuel gas within the fluidized bed 21 is provided within the fluidized bed 21. An air ratio λ of the primary air mixed with the fuel gas jetted from a fuel gas pipe 41 is set to be 0.3 or more. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for operating a fluidized bed incinerator in which a fluidized bed is fluidized to incinerate an object to be incinerated.

  Conventionally, fluidized bed incinerators have been used as waste incinerators or sewage sludge incinerators (see, for example, Patent Document 1). In the fluidized bed incinerator, as shown in FIG. 1, a fluidized bed 21 is formed by loading a fluidized medium in the lower part of the incinerator body 1, and a freeboard 22 is provided above the fluidized bed 21. Then, the incinerated material is put into the incinerator main body 1 and mixed into the fluidized bed 21, and fluidized and stirred by the fluidized air from the air diffuser 3 provided in the lower part of the fluidized bed 21. By injecting the fuel gas mixed with primary air into the fluidized bed 21 and burning it by the combustion means 4 provided in the incinerator, the incinerated material mixed in the fluidized bed 21 is incinerated uniformly and efficiently. is there.

JP 2000-81206 A

  By the way, in the above conventional example, the gas pre-mixed with the fuel gas at the air ratio λ = approximately 0.1 is discharged from the gas gun 4a and the flowing air is discharged from the air diffuser 3a to flow the fuel gas. Although the incineration object is incinerated by burning in the floor 2, since there is abundant secondary air such as fluidized air, operation is performed with the air ratio λ of the primary air being suppressed to a low value of about 0.1. It was a thing.

  However, in this case, the fluidized bed 21 is not heated effectively, and the basic unit (the amount of heat necessary for burning the incinerated material of unit weight, the lower the amount of heat, the higher the basic unit) is low and the efficiency is high. It was bad.

  In order to improve this efficiency, it is conceivable that fuel gas is mixed into the flowing air sent to the air diffuser 3a.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a method for operating a fluidized bed incinerator capable of improving the combustion efficiency of fuel gas in the fluidized bed. Is an issue.

  In order to solve the above problem, in the invention according to claim 1, a fluidized bed 21 is formed in the lower part of the incinerator body 1, and the fluidized bed 21 and the fluidized bed 21 are formed in the lower part of the fluidized bed 21. Air diffuser 3 for diffusing fluid air for fluidly stirring the mixed incinerated material is provided. Combustor 4 for injecting fuel gas mixed with primary air into the fluidized bed 21 and combusting in the fluidized bed 21 In which the air ratio λ of the primary air mixed into the fuel gas ejected from the fuel gas pipe 41 is 0.3 or more.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, primary air mixed in the fuel gas is hot air.

  In the present invention, by setting the air ratio λ of primary air to 0.3 or more, the fuel gas is well combusted in the fluidized bed and the combustion efficiency is increased.

1 is an overall schematic diagram of a fluidized bed incinerator. It is sectional drawing of a gas gun same as the above.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  In the fluidized bed incinerator, sludge, general waste, industrial waste, and the like are listed as incinerated materials, but there is no particular limitation.

  The incinerator main body 1 which is the main body of the fluidized bed incinerator is formed of a refractory material, and a fluid medium such as sand is loaded at the bottom of the incinerator main body 1 as shown in FIG. The fluidized bed 21 is formed with this fluidized medium. The fluidized bed 21 is provided with an air diffuser 3 a as the air diffuser 3, and fluid air is supplied to the air diffuser 3 a through the air supply path 12. A plurality of the air diffusion tubes 3a are arranged in parallel. The fluid medium and the incinerated material can be mixed and agitated by supplying fluid air from the air supply path 12 to the air diffuser 3a. Further, a gas gun 4a is disposed on the air diffusion pipe 3a as the combustion means 4, and fuel gas is ejected from the gas gun 4a into the fluidized bed 21 to form a flame in the fluidized bed 21 and burn. Yes. The gas gun 4a has a structure as shown in FIG. 2, and a main fuel gas pipe 41 and a pilot gas pipe 42 are juxtaposed in the outer pipe 40, and the fuel gas pipe 41 and the pilot gas pipe 42 are provided. Can be supplied with premixed fuel gas, which is a mixture of fuel gas and primary air. In the present invention, the air ratio λ of the primary air to the theoretical air amount is 0.3 or more, preferably 1.0.

  In addition, an air introduction port 43 for introducing secondary air is provided at the base of the outer tube 40, and the secondary air introduced from the air introduction port 43 is taken in at the tips of the fuel gas tube 41 and the pilot gas tube 42. It comes to burn. A matrix 44 for avoiding a fluid medium such as sand is mounted in front of the front end of the outer tube 40.

  The upper part in the incinerator body 1 is a free board 22 (combustion chamber), and a temperature raising burner 15 is attached to the free board 22. This temperature raising burner 15 is combusted when the incinerator main body 1 is started up to heat the freeboard 22. Further, an incinerator input port 16 is provided in the upper part of the incinerator main body 1 to input an incinerator to be incinerated. An exhaust port 17 is provided at the upper end of the incinerator main body 1, and exhaust gas can be exhausted from the exhaust port 17 through the exhaust path 13 to the outside. A heat exchanger 14 is disposed in the middle of the exhaust path 13, and heat exchange is performed by the heat exchanger 14 with the flowing air supplied to the diffuser pipe 3a via the air supply path 12. The flowing air can be heated and supplied with gas. A discharge port (not shown) is provided at the lower end of the incinerator body 1.

  The fuel gas used as fuel in the incinerator main body 1 is generally city gas, for example, natural gas called 13A. Such fuel gas is not limited to city gas, but may be propane gas or butane gas.

  In the fluidized bed incinerator, the incineration object is incinerated as follows. The incinerated material is introduced from the incinerated material inlet 16, and the incinerated material is mixed and stirred together with the fluid medium by the diffusing air of the flowing air. When the fluidized bed incinerator is started, the temperature raising burner 15 is burned and the fluidized bed 21 and the free board 22 are heated. A flame is ejected from the gas gun 4a into the fluidized bed 21, the fluidized bed 21 is heated, fluidized air is diffused from the diffuser 3a, the fluidized medium in the fluidized bed 21 is fluidly stirred, and the inside of the fluidized bed 21 is 800 ° C. The material to be incinerated is incinerated by being heated to the extent.

  In the present invention, since the air ratio λ of the primary air to the theoretical air amount is set to 0.3 or more (preferably 1.0), the fuel gas burns well in the fluidized bed and the combustion efficiency is improved as compared with the conventional case. ing. That is, conventionally, a large amount of primary air is supplied and a large amount of air is heated together with secondary air such as fluidized air, thereby avoiding a decrease in the temperature of the fluidized bed 21 and the incinerated material. Therefore, the primary air amount is suppressed to a value as low as about 0.1 in the air ratio λ. However, this reduced the amount of combustion in the fluidized bed 21 and reduced the basic unit. Therefore, in the present invention, by increasing the air ratio λ to 0.3 or more, the amount of combustion in the fluidized bed 21 can be increased and the basic unit can be improved.

  Further, by using hot air as the primary air mixed into the fuel gas, combustion efficiency can be further improved and methane slip can be eliminated.

DESCRIPTION OF SYMBOLS 1 Incinerator main body 10 Through-hole 11 Furnace wall 12 Air supply path 13 Exhaust path 14 Heat exchanger 15 Temperature rising burner 16 Incinerator inlet 17 Exhaust outlet 21 Fluidized bed 22 Free board 3 Air diffuser 3a Air diffuser 4 Combustion means 4a Gas gun 40 Outer pipe 41 Fuel gas pipe 42 Pilot gas pipe 43 Air inlet 44 Matrix

Claims (2)

  A fluidized bed is formed in the lower part of the incinerator main body, and a diffused means for diffusing fluidized air for fluidly stirring the fluidized bed and the incinerated material mixed in the fluidized bed is provided in the lower part of the fluidized bed, An operation method of a fluidized bed incinerator provided with combustion means for ejecting fuel gas mixed with primary air into a fluidized bed and combusting in the fluidized bed, wherein the primary mixed into the fuel gas ejected from a fuel gas pipe A method for operating a fluidized bed incinerator, wherein the air ratio of air is 0.3 or more.   2. The method for operating a fluidized bed incinerator according to claim 1, wherein the primary air mixed in the fuel gas is hot air.

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