JPH03168510A - Combustion stabilizer for fluidized-bed incinerator - Google Patents

Abstract

PURPOSE:To prevent a variation in a burning state in a short time by allowing a bearer for temporarily receiving article to be burned to protrude in height of predetermined times as large as the height of a steady layer of a fluidized bed at the lower side of the opening of a furnace wall of a chute in which the article to burned is introduced in a steplike section. CONSTITUTION:A bearer 12 of a steplike section protrudes in height of 0.7-1.3 times as large as the height Ho of a steady layer of a fluidized bed 2 at the lower side of a chute 5. The width BW and length BL of the bearer 12 are set to about 0.5-1.5W to the width W of the chute 5. A secondary fluidized gas exhaust port 13 is formed at each steplike rising face 12a of the bearer 12, and fluidized gas is supplied from a tube 14 to be injected. With the struc ture, even if a large quantity of refuse is introduced, it is received by the bearer to prevent abrupt combustion. It is dispersively supplied with the secondary fluidized gas into a furnace, and stably burned.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a combustion stabilization device for a fluidized bed incinerator.

[Conventional technology] As shown in FIG. 5, the conventional fluidized bed incinerator 1 has a fluidized bed 2 in which fluidized sand is circulated and supplied to the lower part of the furnace.
The sand is heated to about 00° C. and the sand is fluidized by the fluidizing air 3, and the material to be burnt introduced from the input chute 5 is combusted in a short time. The unburned gas that has not been completely combusted in the fluidized bed 2 is combusted by the secondary combustion air 4 supplied to the freeboard section 6, and the exhaust gas is discharged from the top of the furnace.

On the other hand, non-combustible materials in the materials to be burned are discharged from the bottom of the furnace together with the fluidized sand. The fluidized sand is then separated and recycled into the furnace.

In order to control the combustion state of this fluidized bed incinerator,
For example, as disclosed in Japanese Unexamined Patent Publication No. 53-148165, a method is used in which the oxygen concentration in exhaust gas is detected and the amount of combustible material, such as garbage, is controlled.

[Problem to be solved] By the way, for example, when a large amount of material to be combusted is charged into the furnace from the charging chute at once, combustion in the fluidized bed is carried out for a short period of time as described above, so there may be a shortage of combustion air. A large amount of unburned gas may be generated. This large amount of unburned gas is discharged outside the furnace without being completely combusted even in the freeboard section. The oxygen rA degree in this exhaust gas decreases and contains harmful gases such as CO, which poses a problem in terms of environmental management.

In such cases, even if you try to control the operation of the furnace using the oxygen concentration in the exhaust gas as described above, the current oxygen concentration meter has a delay of several tens of seconds in determining AIIJ, so it is difficult to control the operation of the furnace based on the oxygen concentration in the exhaust gas. I can't deal with it.

An object of the present invention is to provide a combustion stabilization device for a fluidized bed incinerator that can solve the above-mentioned problems.

[Means for Solving the Problems] The combustion stabilizing device for a fluidized bed incinerator of the present invention stabilizes the static bed height of the fluidized bed at the lower side of the furnace wall opening of the combustion material input chute of the fluidized bed incinerator. A pedestal with a step-like cross section that temporarily receives the material to be burned is placed at a height of 0.7 to 1.3 mm.
It is provided so as to protrude from the furnace wall. A discharge port for secondary fluidizing gas is provided on the rising surface of the stepped pedestal.

[Operation] When a particularly large amount of combustible material is charged into the furnace from the input chute, this large amount of combustible material is temporarily received by the step-like pedestal. The pedestal has a lower rate of heat conduction than sand, which prevents rapid combustion within the furnace. In this way, unburned gas can be prevented from being discharged to the outside of the furnace. Incidentally, the material to be burned received on the pedestal 12 is sent into the furnace along with the movement of sand along the steps that gradually become lower toward the inside of the furnace.

In addition, by discharging secondary fluidizing gas from the rising surface of the stepped pedestal, this pedestal functions as a secondary dispersion temporary, and by suppressing combustion on the pedestal, JIH can reduce the amount of discharged gas and sand. The movement sends the combustible material caught on the pedestal into the furnace.

[Example] Hereinafter, an example of the apparatus of the present invention will be described with reference to the drawings.

A step-shaped pedestal 12 is provided below the chute 5 for charging the material to be burnt, protruding from the furnace wall 11. The steps of this pedestal 12 are gradually lowered toward the inside of the furnace. A large number of secondary fluidizing gas discharge ports 13 are opened on each rising surface 12a of this pedestal 12. The fluidizing gas is supplied from the furnace wall 11 side via piping 14.

The size and arrangement position of the pedestal 12 are shown in FIG.

The installation height Bh of the pedestal 12 is (0.7 to 1.3) Ho
(Ho is the static height of the fluidized bed 2). this is,
Below 0.7 Ho, the pedestal is completely buried in the sand, making it impossible to temporarily suppress combustion, and above 1.3 Ho, the edge of the sand in the fluidized bed is cut off. This is due to the inability to function as a quadratic dispersion temporary. In addition, the width Bw and length Bg of the pedestal 12 are:
Each (0.5 to 1.5) W (W is the width of chute 5)
It has become.

A large amount of material to be burned is thrown in from the charging chute 5 at once, and is temporarily received by the receiving stand 12. In this way, a large amount of materials to be combusted are thrown into the sand at once, preventing sudden combustion and smoothing out the combustion. This prevents the generation of unburned gas and prevents the unburned gas from being discharged outside the furnace. Incidentally, the material to be burned received on the pedestal 12 is sent into the furnace along with the movement of sand along the steps that gradually become lower toward the inside of the furnace.

In addition, when the secondary fluidizing gas is discharged from the rising surface of the stepped pedestal, the combustible material temporarily caught on the pedestal 12 is suppressed and combusted by the secondary fluidizing gas. , the movement of the discharge gas and sand directs it into the furnace.

As the fluidizing gas, for example, water vapor or the like is used in addition to air, and by controlling the amount and amount of these gases, the degree of combustion can be controlled.

[Effects of the Invention] The combustion stabilizing device for a fluidized bed incinerator of the present invention is as described above, and when a large amount of material to be combusted is charged into the furnace from the input chute at once, this large amount of material to be combusted is is temporarily received by a stepped pedestal.

This prevents rapid combustion from occurring within the furnace. In this way, unburned gas can be prevented from being discharged to the outside of the furnace. Incidentally, the combustible material received on the pedestal 12 is
The movement of sand and the noise (
is sent into the furnace.

In addition, by discharging secondary fluidizing gas from the rising edge of the stepped pedestal, this pedestal functions as a secondary dispersion gas, suppressing combustion on the pedestal, and reducing the amount of fluid received on the pedestal. The materials to be burned can be sent to the furnace pile by the movement of discharged gas and sand.

[Brief explanation of the drawing]

Fig. 2 is an explanatory diagram showing an example of the structure of the device of the present invention, Fig. 2 is an explanatory diagram showing the arrangement of the cradle, Fig. 3 is a sectional view of the cradle, and Fig. 4 is an explanatory diagram showing the arrangement of the cradle. FIG. 5 is an explanatory diagram showing the installation and size of the fluidized bed incinerator. 11...Furnace wall 12...Bed 12a...Rising surface 13...Secondary fluidizing gas discharge port 1 Fig. 5 Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Scope of Claims] 1) Located below the furnace wall opening of the combustion material input chute of the fluidized bed incinerator, at a height of 0.7 to 1.3 of the static bed height of the fluidized bed, A combustion stabilization device for a fluidized bed incinerator, comprising a pedestal with a step-like cross section that temporarily receives materials to be combusted, protruding from the furnace wall. 2) The apparatus according to claim 1, wherein a discharge port for secondary fluidizing gas is provided on a rising surface of the step-shaped pedestal.