JPH06347005A - Combustion device for powder - Google Patents

Abstract

PURPOSE:To gasify powder fuel in burning it so as to improve the combustion efficiency by a method wherein a screw conveyor for carrying powder fuel is provided inside a combustion furnace and to a burner nozzle which extends from the forward end of the outer cylinder of the screw conveyor and looks out through the exhaust gas hole of the combustion furnace a stream of air for combustion is sent through the shaft, which is hollow, of the screw conveyor. CONSTITUTION:A screw conveyor 9 for conveyance is held horizontally inside a combustion furnace 1. From the forward end of the outer cylinder 11 of this conveyor 9 a burner nozzle 17 extends in such a manner as to look out through the exhaust gas hole 7 of the combustion furnace 1. The shaft 13a of the screw conveyor 9 is hollow along the axis and its rear end is connected to a blower through a swivel joint 19. Holes 23 are opened through the burner nozzle 17 circumferentially. In the upper part of the combustion furnace 1 a screw conveyor 25 for feeling powder fuel is provided as a means of feeding powder fuel to the combustion furnace 1 and the screw conveyor 9 for conveyance. As a result, powder fuel can be gasified for the combustion and an improvement in combustion efficiency can be achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for burning finely crushed wood, plastic, rubber, etc., which itself can be used for incineration of garbage, and can also heat a boiler with the generated flame, It can be used to incinerate waste.

[0002]

2. Description of the Related Art A conventional powder combustion apparatus typified by pulverized coal is one in which powder is mixed with air and injected into a furnace for combustion. However, unlike powdered fuels and liquid fuels, powders have an order of magnitude larger particles, and thus have poor combustion efficiency. Further, if the powder contains moisture, it is difficult to burn, so that it is necessary to keep the powder in a dry state, which causes a risk of dust explosion.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to gasify and burn powder to improve combustion efficiency. Also, make it possible to burn powder containing moisture.

[0004]

In the powder combustion apparatus of the present invention, a conveying screw conveyor for transferring powder fuel is installed in the combustion furnace. A burner nozzle extends from the tip of the outer cylinder of the screw conveyor and is seen through the exhaust port of the combustion furnace. A means for sending combustion air to the burner nozzle through the hollow shaft of the screw conveyor is provided.

[0005]

The powder fuel is conveyed in the conveying screw conveyor toward the burner nozzle, and is exposed to the heat inside the combustion furnace. Since there is no oxygen in the conveying screw conveyor, the powder is in a dry state. That is, the powder is thermally decomposed to generate a flammable gas. On the other hand, combustion air is sent from the blower through the screw shaft, encounters combustible gas in the burner nozzle, and blows out as flame from the barber nozzle.

[0007]

EXAMPLE A combustion furnace 1 is equipped with a roster 3 inside,
Powder fuel burns on it. Reference numeral 11 is a blower for supplying combustion air, and reference numeral 7 is an exhaust port. A conveying screw conveyor 9 is horizontally supported inside the combustion furnace 1. The conveyor 9 has a screw 13 rotatably fitted in an outer cylinder 11, and the screw 13 is a motor 15
It is driven to rotate.

A burner nozzle 17 extends from the tip of the outer cylinder 11 of the conveyor 9, and this nozzle is seen through the exhaust port 7 of the combustion furnace 1 to the outside. The shaft 13a of the screw 13 is hollow, and its rear end is connected to a blower (not shown) via a swivel joint 19. A hole 23 is formed in the peripheral surface of the burner nozzle 17.

On the upper part of the combustion furnace 1, a screw conveyor 25 for supplying powder fuel is installed. This conveyor is also an outer cylinder 27
A screw 29 is rotatably fitted therein, and the screw is driven by an electric motor (not shown).
At the rear of the outer cylinder 27 of the conveyor 25, there is a receiving port 33, to which a hopper 35 is attached. Outer cylinder 2
7 is further provided with a first outlet 37 that communicates with the upstream side of the conveying screw conveyor 9 and an elongated second outlet 39 that communicates with the combustion furnace 1. A damper 41 for adjusting the flow rate is provided in the first outlet 37.

The front and rear of the supply screw conveyor 25 are connected by a return 43 conveyor. The return conveyors are three screw conveyors 43a, 43 connected in a U shape.
It consists of b and 43c.

Explaining the operation of this apparatus, the powder fuel obtained by finely crushing wood, plastic, rubber, etc. is used as the hopper 3.
Put in 5. The powder falls on the supply conveyor 25, and while being conveyed by the conveyor, a part of the powder falls on the transfer conveyor 9 through the first drop port 37. The rest is further conveyed by the supply conveyor 25 and is fed from the second outlet 39 to the combustion furnace 1
fall into. The remaining powder is returned to the starting point of the supply conveyor 25 by the return screw conveyor 43.

The powder that has fallen from the first dropping port 37 burns in the combustion furnace 1, and the ash falls below the roast 3. Second
The powder that has fallen through the dropping port 39 is sent forward through the conveying screw conveyor 9 and, during this time, is exposed to the high temperature of the combustion furnace 1. However, since there is no oxygen in the screw conveyor 9, it does not burn and the powder is dry-distilled.
That is, the powder is thermally decomposed at high temperature, combustible gas is generated, and the powder becomes carbonaceous.

The combustible gas and carbonaceous matter are blown out from the burner nozzle 17 together with the air blown from the tip of the screw shaft 13a. At this time, the flame in the combustion furnace 1 is sucked from the hole 23 of the nozzle 17 and ignited. In this way, flame is continuously blown out from the tip of the nozzle 17. This heat heats a boiler (not shown). The ash produced by burning the charcoal is collected in the flue of the boiler.

[0014]

According to the invention of claim 1, since the screw conveyor for transferring the powder to the burner nozzle is placed in the combustion furnace, the powder is heated and gasified while passing through the screw conveyor, and the screw is used. It burns out from the burner nozzle together with the air supplied from the shaft. Since the powder is gasified and burned in this way, the combustion efficiency is excellent.

Further, when the powder contains moisture, when heated in the screw conveyor, the moisture becomes steam, which does not hinder the combustion of dry distillation gas. Therefore,
It is not necessary to keep the powder as fuel dry.
The danger of dust explosion can be eliminated.

According to the second aspect of the present invention, the burner nozzle is provided with a hole in the peripheral surface for sucking the flame of the combustion furnace, so that the initial ignition is ensured and the burner is prevented from being blown out. To do.

In the apparatus of claim 3, a supply screw conveyor is laid from the powder storage source, and the powder fuel is supplied to both the transfer screw conveyor and the combustion furnace from the supply screw conveyor. The structure of is simple.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a powder combustion device.

FIG. 2 is a transverse sectional view of the same.

FIG. 3 is a perspective view of a burner nozzle.

[Explanation of symbols]

 1 Combustion Furnace 7 Exhaust Port 9 Transfer Screw Conveyor 11 Outer Cylinder 13 Screw Shaft 17 Biner Nozzle 21 Blower 23 Hole 25 Supply Screw Conveyor 27 Outer Cylinder 37 First Droplet 39 Second Droplet

Claims (3)

[Claims] 1. A combustion furnace (1), a screw conveyor (9) for transferring powdered fuel, which is installed in the combustion furnace, and a tip of an outer cylinder (11) of the screw conveyor. Powder combustion apparatus comprising a burner nozzle (17) extending from the exhaust port (7) of the combustion furnace and a means for sending combustion air to the burner nozzle through a hollow shaft (13a) of the screw conveyor. . 2. The powder combustion apparatus according to claim 1, wherein a hole (23) for sucking flame of the combustion furnace is formed in a peripheral surface of the burner nozzle. 3. A supply screw conveyor (25) is laid from a powder storage source, and an outer cylinder (27) of the supply screw conveyor communicates with an upstream side of the transfer screw conveyor. 37) The powder combustion apparatus according to claim 1 or 2, further comprising a second outlet (39) communicating with the combustion furnace.