JPS6321411A - Fluidized bed layer incinerator - Google Patents

Abstract

PURPOSE:To reduce the installation space and prevent spray water droplets from descending by mounting a gas cooler having a gas inlet smaller than the section area of the upper secondary burning zone and the section area of said gas cooler directly on top of the incinerator so they may form an integral body. CONSTITUTION:A gas cooler 5 is directly mounted on top of the upper secondary burning zone 3 of a fluidized bed layer incinerator 1 through a gas passage 9 acting as a gas inlet so they may form a one-piece. The section area of said gas passage 9 is made smaller than the section area of the secondary burning zone 3 and the section area of the gas cooler 5 so the gas inlet may be throttled. In this instance, the gas cooler 5 has in its lower center a gas inlet, and the gas passage 9 has a conical part whose cross section is smaller toward said gas. As the gas flow speed at the gas cooler inlet is made larger, cooling spray water droplets are prevented from descending to the burning zone, allowing an operation without causing a temperature reduction.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a fluidized bed incinerator for incinerating municipal waste, percussion waste, industrial waste, and other wastes using a fluidized bed. It is related to.

[Conventional technology]

Conventionally, in this type of fluidized bed incinerator, as shown in FIG.
It was common to install them separately and connect them with a duct 4. Although this type is functionally superior in terms of combustion theory, it requires a large installation space due to the installation of the fluidized bed incinerator 1 and gas cooler, and the piping connection structure, which poses a practical problem. From the viewpoint of reducing the amount of gas and making the equipment more compact, it has recently been implemented to mount the gas cooler 5 directly on the top of the incinerator 10 and integrate it with the incinerator, as shown in the third diagram.

(Problems to be Solved by the Invention) However, with such an incinerator structure, in terms of combustion performance, ■ cooling spray water droplets descend into the incinerator secondary combustion seam 73, lowering the combustion temperature; Generates incomplete combustion gas such as CO.

- Since the gas cooler section becomes a low-temperature zone, the secondary combustion zone of the incinerator receives a radiation cooling effect, which similarly lowers the combustion temperature and suppresses complete combustion.

Therefore, as a countermeasure against this problem, it has conventionally been necessary to provide a buffer zone member 8 between the gas cooler 5 and the top of the incinerator 1 to prevent the above-mentioned negative effects.

That is, taking FIG. 2 as an example, if the gas cooler 5 is placed directly above the combustion zone 3, gas cooling will occur from the flame 10 in the incinerator 1! The solid angle facing S5 is β (if the ideal solid angle is α, then β>α), which has the disadvantage of often lowering the combustion temperature. For this reason, it has become necessary to provide the buffer zone member 8 in the middle to reduce the solid angle β to α. For this reason, even if the installation space can be reduced, there is a disadvantage in that the device must add unnecessary height in the height direction.

The present invention eliminates these conventional drawbacks, reduces the installation space, prevents spray water droplets, and also prevents radiation cooling of the gas cooling section, thereby improving the secondary combustion zone of the incinerator. The purpose of the present invention is to provide a fluidized bed incinerator equipped with a gas cooler that allows complete combustion without affecting the temperature drop in a pre-built vehicle and at low cost.

[Means for solving problems]

The present invention aims to reduce the cross section of the gas passage between the secondary combustion zone in the incinerator and the gas cooler following it to such an extent that sprayed water droplets do not reach the secondary combustion zone and to the extent that the radiation cooling effect is minimized. A gas cooler with a gas inlet having a cross-sectional area smaller than the cross-sectional area of the upper secondary combustion zone of the fluidized bed incinerator and the cross-sectional area of the gas cooler is mounted directly on the top of the incinerator to form an integrated structure. This is a fluidized bed incinerator characterized by:

〔Example〕

To explain the present invention with reference to the embodiment shown in FIG.
A gas cooler 5 is directly installed in the upper part of the upper secondary combustion zone 3 of the fluidized bed incinerator 1 with the fluidized bed 2 which is fluidized by four people from the bottom via the gas passage 9 which serves as the gas population. It is integrally connected. The cross-sectional area A2 of this gas passage 9 is smaller than the cross-sectional area AI of the secondary combustion zone 3, and the gas population is narrowed down so that the cross-sectional area A of the gas cooler 5 is made smaller. In this case, the gas cooler 5 is provided with a gas inlet in the lower central part, and a conical portion with a gradually decreasing cross-sectional area toward the gas is provided as a gas passage 9. That is, the inner wall structure is such that it smoothly connects the cross-sectional area A of the gas inlet to the cross-sectional area A of the main body of the gas cooler 5. Further, the gas outlet formed at the top of the fluidized bed incinerator 1 can also be integrally connected as an opening having a cross-sectional area A2 in order to communicate with the gas passage 9 of the gas cooler 5.

The cross-sectional area A2 of the gas inlet of the gas passage 9 is preferably set so that the solid angle α of the gas cooler 5 from the flame lO in the incinerator 1 is an ideal solid angle, and its arrangement is also taken into consideration. That is, the cross-sectional area of each part A + , A z , A 3
In the relationship, A z / A+ should be determined from the relationship between both the spray particle diameter and the amount of radiant heat absorption. Regarding radiant heat absorption, it is necessary to determine A2 so that the average gas temperature in the secondary combustion zone 3 can be maintained at the temperature required for complete combustion or complete decomposition of odor components (generally 750°C or higher). ). This can be evaluated by the solid angle α of the gas cooler 5 from the combustion flame.

That is, in the example of FIG. 1, this relationship is α=0, which means that there is no effect of radiation from the gas cooler 5 at all.

The relationship of Ax/As relates to contact evaporation and distance between descending particles of water droplets injected from the spray nozzle and gas, and generally the relationship should be set as Ax/As < 1 - < At/Ax ≧ In case 1, spray particles may fall into the gas passage 9, which is undesirable.) This is also necessary in order to reduce the radiation cooling effect of the gas cooler.

In the figure, 6 is a spray nozzle for supplying cooling water, 7 is an exhaust gas outlet, and 11 is an air distribution plate.

〔Effect of the invention〕

The present invention is capable of reducing the gas population of the gas cooler from the cross-sectional area of the incinerator and the gas cooler without providing a buffer zone even when the gas cooler is directly connected to the top of the fluidized bed incinerator and integrated. Since the gas flow rate at the gas cooler inlet can be made faster, cooling spray water droplets can be prevented from falling into the combustion zone, and operation can be performed without lowering the combustion temperature.Moreover, the radiation cooling effect of the gas cooler is small and the combustion temperature does not decrease. This prevents the generation of incompletely combusted gases such as CO, eliminates the need for a buffer zone required in conventional gas-cooled integrated fluidized bed incinerators, and provides a compact incinerator that can reduce the height of the equipment. can.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG.
Each figure is a longitudinal sectional view of a conventional example. DESCRIPTION OF SYMBOLS 1... Fluidized bed incinerator, 2... Fluidized bed, 3... Secondary combustion zone, 4... Exhaust gas duct, 5... Gas cooler, 6... Spray nozzle, 7...・Exhaust gas outlet, 8
...Buffer zone member, 9...Gas passage, 10...
combustion flame.

Claims (1)

[Claims] 1. In a fluidized bed incinerator configured by directly connecting a gas cooler to the top of an incinerator equipped with a fluidized bed, a cross section of the upper secondary combustion zone of the fluidized bed incinerator and the gas cooler A fluidized bed incinerator characterized in that a gas cooler with a gas inlet having a cross-sectional area smaller than the cross-sectional area is mounted directly on the top of the incinerator to form an integrated structure. 2. Claim 1, wherein the gas cooler is provided with a gas inlet at the center of the lower part, and includes a conical part whose cross-sectional area gradually decreases toward the gas inlet. The fluidized bed incinerator described. 3. The gas inlet is arranged in the incinerator so that the solid angle facing the gas cooler from the flame is an ideal solid angle α, according to claim 1 or 2. Fluidized bed incinerator.