JPS6017679Y2 - Fluidized bed furnace - Google Patents

Description

[Detailed explanation of the idea] This invention relates to the structure of a fluidized bed reactor.

Fluidized bed furnaces are used to incinerate waste, and in order to effectively utilize the heat energy generated, a structure in which the side walls are water-cooled has been proposed.

On the other hand, a fluidized bed boiler that uses coal as a fuel and uses it as a boiler has been developed and used.

The temperature in the fluidized bed is as high as 500°C to 1000°C depending on the material to be incinerated, and in the case of granular coal combustion, it is set at about 700°C to prevent the generation of NOx.

For this reason, the bottom plate is made of a stainless steel plate that can withstand high temperatures with many holes for air passages, or a fireproof material.

This is expensive and causes problems such as damage due to cracks due to repeated bending and deformation of the bottom plate due to the temperature difference between the top of the bottom plate inside the furnace and the bottom side of the air chamber when starting or stopping the furnace.

This idea uses ordinary steel plates and pipes to reduce material costs and proposes effective use of the bottom plate as a heat transfer surface.

In short, this idea is that in a fluidized bed furnace, the furnace side wall has a cooling tube structure, the bottom of the fluidized bed furnace has a bottom plate structure including a cooling tube, the bottom plate is provided with a flow air passage, and the air passage is provided below the bottom plate. The furnace is characterized by being a fluidized bed furnace equipped with an air chamber for supplying fluidizing air to the furnace.

This idea will be explained below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of the bottom of the fluidized bed furnace including the fluidized bed section.

Here, the fluidized bed furnace refers to a furnace including a waste incinerator, a pyrolysis furnace, a fluidized bed boiler, and the like.

FIG. 1 shows a fluidized bed boiler 1 having a water-cooled wall structure, and the side walls have a wood tube wall structure (hereinafter simply referred to as a membrane panel).

A membrane panel is a single plate-like body (panel) made by arranging multiple tubes in parallel with the required width and welding the tubes together with narrow root plates.
It is widely used in boilers because of its characteristics such as efficient heat transfer without causing gas leakage.

Reference numeral 2 represents an evaporator tube or a superheater tube provided within the fluidized bed.

The in-bed burner, starting burner, and incineration material supply nozzle are omitted in this drawing.

3 is an air chamber, and a bottom plate 4 including a cooling pipe is mounted above the air chamber.

In this case, the surface of the bottom plate containing the pipe axis of the cooling pipe is about 7
° Tilt.

This slope is necessary and preferred for the circulation of cooling water.

A large number of bubble caps 6 are provided as flowing air passages in the flat fins 5 that connect the cooling pipes of the bottom plate, and are used as a perforated plate.

An example of a bubble cap is normally shown in Fig. 3, with a lid 6a provided on the top surface of a small-diameter tube and an air hole 7 on the side.
It is something that has.

The lid 6a prevents the fluidized medium from entering the air chamber when the furnace is shut down.

The air passage may be formed by providing a large number of small holes in the fin portion.

For the supply of flowing air, the air chamber provided on the lower side of the sloping bottom plate is made into an enlarged passage type, and an air supply port 11 is provided on the right side of the drawing, and when air is supplied from this, an equal amount of air is ejected from each bubble cap. It has the effect of

Further, when the medium extraction port 10 is provided on the lower side, the inclination of the bottom plate facilitates extraction of the fluidized medium.

The upper end of the bottom plate can be connected to a header 8 to which the lower ends of the cooling pipes of the side walls are connected.

Further, in order to properly maintain the internal temperature of the layer, studs 12 may be provided on each membrane panel, and a layer 9 of refractory material such as plastic chrome ore may be provided.

By implementing this idea, the heat generated in the layer can be absorbed by the bottom plate to generate steam, and since the cooling water flows through the cooling pipes that are the constituent members of the bottom plate, the upper surface of the bottom plate on the furnace side and the air This has the effect that there is no temperature difference between the base plate and the lower surface on the chamber side, no cracks are generated due to deformation of the bottom plate, and the life of the bottom plate is extended.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a fluidized bed furnace according to this invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is a partial partial sectional view taken along the line BB in FIG. 1... Fluidized bed boiler, 2... Evaporation tube,
3...Air chamber, 4...Bottom plate, 5...
...Flat fin, 6...Bubble cap, 7...Air hole, butt...Header, 9...
...Fireproof material layer, 10... Outlet port, 11
...Air supply port, 12...Stud.

Claims (1)

[Scope of utility model registration request] In a fluidized bed reactor, the furnace side wall has a cooling tube wall structure, the bottom of the fluidized bed has a bottom plate structure including a cooling tube, a fluidizing air passage is provided in the bottom plate, and a fluidizing air is provided in the air passage below the bottom plate. A fluidized bed furnace characterized by having a supply air chamber.