JPS59104006A - Fluidized-bed combustion furnace provided with fluid fuel spraying device - Google Patents

Abstract

PURPOSE:To prevent a spray pipe from being choked with fluid and the occurrence of seizure of the spray pipe, by a method wherein a spray nozzle mounted to the forward end of an injection pipe is situated in a fluid medium to inject fluid fuel in the fluid medium, and an injection pipe is cooled through passage of a refrigerant between the injection pipe and a protection pipe. CONSTITUTION:An injection pipe 7, extending through a side wall, is situated above a dispersion pipe 3/ a dispersion nozzle 4 in a manner to be embedded in a fluid medium 2. Concentrated fluid is injected in a fluid medium to be burnt in a high temperature fluid medium and is self-burnt with the aid of the air for fluidization, and combustion gas is exhuasted through a furnace outlet 12. Further, the injection pipe 7 is provided at the outside thereof with a protection pipe 8 to prevent the injection pipe 7 from making contact with the fluid medium 2, and also to prevent increasing of the temperature of the injection pipe 7 by passing a cooling air through a space 13 between the protection pipe 8 and the injection pipe 7.

Description

[Detailed Description of the Invention] When a fluidized bed combustion furnace burns liquid such as industrial waste liquid or heavy oil as a fuel, it is necessary to burn the liquid and maintain the temperature of the fluidized medium itself at a high temperature. It will be put into a tank and burnt while flowing. Moreover, in order to uniformly inject the fuel into the fluidized medium, seven or more spray tubes are inserted horizontally from the side wall of the furnace or vertically from the bottom of the furnace and sprayed with pressure, air, or Atomization with steam is a good idea.

During normal combustion, the fluidizing medium is between 70θ and θθ.
When a liquid fuel injection pipe is installed inside this temperature, the injection pipe that comes into direct contact with the fluid medium is quickly heated due to its high heat transfer coefficient, and the temperature inside the injection pipe increases. Even the liquid fuel is abnormally heated and carbonized, and the carbide clogs the spray nozzle, rendering it unable to function (not only does it cause the spray pipe itself to burn out).

SUMMARY OF THE INVENTION An object of the present invention is to provide a fluidized bed combustion furnace that can prevent the above-mentioned drawbacks and smoothly charge liquid fuel into a high-temperature fluidized medium and burn it.

The configuration and effects of the present invention will be explained in detail below based on the drawings.

FIG. 7 is a schematic diagram of a fluidized bed combustion furnace according to the present invention, and FIG. 2 is a detailed diagram of a liquid fuel spraying device, where 1 is a fluidized bed combustion furnace, 2 is a fluidized medium, 3 is an aeration pipe, and 4 is an aeration tube. The nozzle -5 is a forced fan, and when the forced fan 5 blows air through the aeration tube and the aeration nozzle, the fluidized medium starts to flow within the fluidized bed.

Flammable concentrated liquid generated at a metal tile product processing factory (absolutely dry high calorific value 6θO1eaf/I+g, water content approximately t o 96)
) in a fluidized bed, an injection pipe is inserted into the fluidized medium from the side wall of the fluidized bed furnace, the injection nozzle at the tip faces into the fluidized medium 2, and the other end is connected to the concentrate pump 6 and air. The concentrated liquid is pressurized by the concentrated liquid pump 6 in communication with a compressor (not shown), and is supplied to the injection pipes from the liquid fuel port 9, and the compressed air for atomization is supplied to the injection pipes from the air inlet 10. 7 and the two are mixed inside the injection pipe 7 and then ejected from the spray nozzle 11 into the fluidized bed.

The injection pipe 7 penetrates the side wall and faces above the dispersion pipe 30 and the dispersion nozzle 4 so as to be buried in the fluidized medium 2, and the concentrated liquid is jetted into the fluidized medium and is heated to a high temperature. Burning inside.

It self-combusts with the fluidizing air, and the combustion gas is discharged from the furnace.

Note that if the injection tube 7 is directly exposed in the fluidized bed at this time, the injection tube will be immediately heated by contact with the fluidized medium at a high temperature of 700 to θθ0°C, and the concentrated liquid inside the injection tube will be further heated. It will heat up, carbonize, and block the spray nozzle.

Therefore, in the present invention, a protection tube 8 is provided on the outside of the injection tube to avoid contact between the injection tube 7 and the fluidized medium 2, and at the same time, air cooling is introduced into the space 13 between the protection tube 8 and the injection tube 7. This prevents the temperature of the injection pipe from rising. This cooling air branches at the outlet of the forced fan 5, cools the injection pipe from the cooling air inlet 14, and finally cools the injection nozzle, and is discharged into the fluidized bed. It was designed to be used as combustion air.

As explained above, the present invention has a spray nozzle attached to the tip of the injection pipe that faces into the fluid medium and sprays liquid fuel into the fluid medium, so that industrial waste liquid can also be effectively combusted. In addition, by attaching a protection tube to the outer periphery of the injection tube and cooling the injection tube by passing a refrigerant between the injection tube and the protection tube, it is possible to prevent liquid blockage in the spray tube and spraying. This is industrially useful as it can prevent the tube itself from burning out.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention, and FIG. 1 is a schematic diagram of a fluidized bed combustion furnace according to the present invention, and FIG. 2 is a detailed diagram of a liquid fuel spraying device. Furnace Fluid medium 6: Concentrate pump 7: Injection tube: Protection tube Ta: Concentrate liquid pump

Claims (1)

[Claims] In a fluidized bed combustion furnace that burns liquid fuel such as flammable industrial waste liquid or heavy oil, a protection tube is provided outside the liquid fuel I injection pipe, and a liquid fuel inlet and compressed air are provided at one end of the injection pipe. An inlet is provided, and a spray nozzle is attached to the other end of the liquid fuel spraying device to mix it into the fluidized medium and ventilate a cooling medium such as air into the space between the injection pipe and the protection tube. Fluidized bed combustion furnace