JPH0810052B2 - Ash melting furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ash melting furnace for melting incineration ash discharged from, for example, an incinerator for municipal waste or an incinerator for industrial waste.

[0002]

2. Description of the Related Art Conventionally, for example, there is an ash melting furnace in which incinerator ash discharged from an incinerator for municipal solid waste is melted and solidified to heat it with a burner in order to reduce the volume and render it harmless.

The bottom wall of the furnace body of this conventional ash melting furnace is
The melting chamber provided with a burner for heating is arranged on the discharge side while being arranged so as to incline downward from the input side of the incinerated ash toward the discharge side of the molten ash, and due to the combustion exhaust gas generated in the melting chamber. A preheating chamber that preheats (drys and heats) the incinerated ash that has been input is disposed on the input side, and further, an ash input hopper and an ash extrusion device are disposed on the input side.

The cross-sectional shape of the bottom wall of the furnace body in the width direction (direction orthogonal to the ash movement direction) is straight, that is, flat. Therefore, the incinerated ash, which has been charged into the furnace body by the extruder from the ash charging hopper, flows from the melting chamber in the preheating chamber while moving to the discharge side on the bottom wall surface of the inclined furnace body. Preheated (dried and heated) by flue gas. Then, the preheated incinerated ash moves to the melting chamber, is heated and melted by the burner provided on the melting chamber side, and then flows down on the bottom wall portion, and the discharge port of the molten ash formed on the discharge side is formed. It was dropped into the cooling tank and cooled and solidified.

[0005]

However, as described above, the cross-sectional shape of the bottom wall of the furnace body in the melting chamber in the width direction is straight, that is, the flat shape over the entire width, and the entire width is increased by the heating burner. The ash in the center melts faster, but the ash on both sides slows to melt, because it is difficult to heat it uniformly over the ash.

Therefore, the flow rate of the molten ash varies on the bottom wall, the discharged ash is not in a uniform state, and the upper surface of the bottom wall is inclined straight toward the discharge port side. Therefore, there is a problem that the ash staying time is short and unmelted ash is easily discharged.Furthermore, the molten ash spreads over the entire upper surface of the bottom wall, and the temperature of the molten ash decreases and solidifies. However, there is a problem that the discharge port is blocked.

Therefore, an object of the present invention is to provide an ash melting furnace which can solve the above problems.

[0008]

In order to solve the above problems, an ash melting furnace of the present invention is an ash melting furnace that heats and melts ash by a burner, and has an ash charging port at one end side. The bottom wall of the furnace body that is formed and has a molten ash discharge port formed on the other end side is provided so as to incline downward from one end side toward the other end side, and at a position near one end in this furnace body A preheating chamber for ash is formed, a melting chamber is provided with a heating burner at a position near the other end, and the cross-sectional shape in the width direction of the portion of the bottom wall portion on the melting chamber side close to the inlet side is formed. In addition to being formed in a shape, the cross-sectional shape in the width direction of the portion near the discharge port is formed in a valley shape.

[0009]

According to the above construction, the front bottom wall portion which is the inlet side of the bottom wall portion on the melting chamber side of the furnace body is formed in a mountain shape, and the rear bottom wall portion which is the discharge side is valley shaped. The molten ash also moves in the width direction because it is formed in the. Therefore, the molten ash is in a uniform state and the ash stays in the melting chamber for a long time, so that it is possible to prevent the ash from moving to the discharge port in an unmelted state.

Further, in the rear bottom wall, the molten ash gathers in the central portion and flows to the discharge port, so that the temperature does not decrease much, and since the molten ash heads to the discharge port while maintaining a large inertial force, the discharge port is blocked. Can be avoided.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes an ash melting furnace for heating and melting ash by a burner, and a bottom wall portion 3 of a furnace body 2 thereof is provided so as to be inclined downward from an ash input side to an ash discharge side.

An ash inlet 21 is formed in the end wall 7 on one end side of the furnace body 2, and a molten ash discharge port (also called a slag port, for example, is formed on the end wall 8 on the other end side. 22 composed of a water cooling pipe) is formed, and a preheating chamber 11 for ash is formed in a portion of the furnace body 2 near the charging port 21, and ash is heated in a portion near the discharging port 22. A melting chamber 12 for melting is formed, and a communication space 13 between the preheating chamber 11 and the melting chamber 12 in the furnace body 2 is narrowed and narrowed. The upper wall 9 of the communication space 13 on the side of the preheating chamber 11 is designed so as to spread upward, that is, be inclined upward so that the pressure loss generated at the throttle portion becomes small.

Further, a step 6 is provided on the bottom wall 3 at the boundary between the preheating chamber 11 and the melting chamber 12 of the furnace body 2 so that the melting chamber 12 side is lowered, and this step 6
The height H of the ash is set based on the ash layer thickness in the preheating chamber 11, that is, the ash layer thickness (usually 100 to 200).
(in the range of about mm), and this step 6 is higher than the height of the ash fixing layer on the bottom wall portion on the melting chamber 12 side, that is, on the melting side bottom wall portion 5. And the intersection point between the line of action of the force of the ash extruding device described later and the upper surface of the melting side bottom wall portion 5,
It is designed to be located sufficiently inside the discharge port 22.

Therefore, the inclination angle of the melting side bottom wall portion 5 is smaller than that of the preheating side bottom wall portion 4 which is the bottom wall portion of the preheating chamber 11. The inclination angle of the preheating side bottom wall portion 4 is set smaller than the friction angle of ash, and is set to, for example, about 10 degrees.

Further, the melting side bottom wall portion 5 is divided into a front portion and a rear portion in the moving direction of the ash, and the inclination angle of the front bottom wall portion 5a in the front-rear direction is within the range of 0 to 5 degrees. The angle of inclination of the rear bottom wall portion 5b in the front-rear direction is within the range of 10 to 20 degrees, for example, around 15 degrees.

As shown in FIGS. 2 to 4, the front bottom wall portion 5a has a mountain shape in the width direction (direction orthogonal to the ash movement direction), and the rear bottom wall portion 5b has a mountain shape. It has a valley shape in the width direction.

The inclination angle θ of the front bottom wall portion 5a in the width direction is within the range of about 2 to 5 degrees, for example. A heating burner 31 for heating ash is attached to the upper wall portion 9 on the melting chamber 12 side, and the upper wall portion 9 of the preheating chamber 11 and the end wall portion 7 in which the charging port 21 is formed are also provided. A combustion exhaust gas outlet 23 is formed at a position away from the exhaust gas by a predetermined distance, and an exhaust gas outlet pipe 24 is connected to the outlet 23.

Further, the charging port 21 of the furnace body 2 has
An ash charging hopper 25 for charging ash is connected, and at the bottom of the ash charging hopper 25, an extruding device 26 for pushing the ash in the ash charging hopper 25 into the furnace body 2 is provided. It is provided.

The push-out device 26 is provided with a push-out member 2 which is provided so as to be able to move in and out of the furnace body 2 from the charging port 21 side.
7 and a cylinder device 28 for moving the pushing member 27 back and forth.

A cooling tank 32 for cooling the molten ash discharged from the discharge port 22 is arranged at a lower portion of the furnace body 2 corresponding to the discharge port 22. A scraping conveyor 33 is arranged to scrape out the ash (slag) that is solidified by cooling the ash.

The undulation of the surface of the bottom wall 5 on the melting side, that is, the undulation, is roughly constituted by a water-cooling pipe or a water-cooling jacket constituting the furnace body, and a refractory material having a high heat conductivity, for example, a lining layer of silicon carbide. Will be adjusted finally.

Therefore, in the above structure, the incineration ash A charged into the furnace main body 2 from the ash charging hopper 25 through the extrusion device 26 is the combustion exhaust gas B flowing from the melting chamber 12 through the communication space portion 13. Is moved from the preheating chamber 11 to the melting chamber 12 side while being preheated (dried and heated), and is heated to a high temperature by the heating burner 31 in the melting chamber 12 to be melted.

The molten ash, that is, molten ash (molten slag) C is discharged from the discharge port 22 into the cooling tank 32, cooled and solidified therein, and taken out as slag by the scraping conveyor 33. Be done.

By the way, as described above, the ash moved from the preheating chamber 11 to the melting chamber 12 side is melted by the heating burner 31 here, and this molten ash is, as shown in FIG. In the front bottom wall portion 5a, the left and right side wall portions 1
After moving to the 0 side, it moves to the rear bottom wall part 5b side, and in this rear bottom wall part 5b, it moves to the center side and goes to the discharge port 22.

As described above, since the molten ash also moves in the width direction of the furnace body 2 in the molten side bottom wall portion 5, the molten ash on the center side and the unmelted ash on the side portion are separated. Since the mixed ash becomes uniform and the ash stays in the melting chamber for a long time, it is possible to prevent the ash from moving to the discharge port 22 in the unmelted state. Further, in the rear bottom wall portion 5b, since the molten ash gathers in the central portion and flows to the discharge port 22, the temperature drop is small and the molten ash heads to the discharge port 22 while maintaining its large inertial force. The blockage at 22 can be avoided.

The ash on the preheating chamber 11 side is pushed out by the extrusion device 26.
However, since the melting-side bottom wall portion 5 is made lower than the preheating-side bottom wall portion 4 by the layer thickness of the ash, the melting-side bottom wall portion 5 is fixed to the melting chamber 12 side. Even when a layer is generated, the ash pushed from the preheating chamber 11 side just pushes the fixed layer, and therefore the behavior of the ash in the melting chamber 12 (supply amount), the temperature in the furnace, The viscosity of molten ash can be manipulated externally.

The preheating chamber 11 in the furnace body 2
Since the communication space 13 between the melting chamber 12 and the melting chamber 12 is narrowed down, the radiant heat from the heating burner 31 is preheated in the preheating chamber 11.
Of the combustion exhaust gas, and the combustion exhaust gas outlet 23 is provided away from the end wall portion 7 of the furnace body 2. Therefore, the combustion exhaust gas flowing into the preheating chamber 11 side is temporarily After colliding with the end wall portion 7 on the input port 21 side and reducing its momentum, that is, after detouring, the ash contained in the combustion exhaust gas is detoured. Sometimes it falls.

By the way, as for the ash extruding device 26 in the above embodiment, one unit may be arranged in the width direction of the furnace body 2, or a plurality of units may be arranged in the width direction. The ash can be controlled more finely by arranging a plurality of units.

[0029]

As described above, according to the configuration of the present invention, the front bottom wall portion on the inlet side of the bottom wall portion on the melting chamber side is formed into a mountain shape, and the rear bottom wall portion on the outlet side is formed. Since it is formed in a valley shape, the molten ash also moves in the width direction, so that the molten ash is in a uniform state and the ash residence time in the melting chamber can be lengthened, so that the ash is not melted. It is possible to prevent the molten ash from moving to the discharge port, and at the rear bottom wall, the molten ash gathers in the center and flows to the discharge port, so that the temperature does not drop much and the discharge port is maintained with its large inertial force. Therefore, it is possible to avoid the occurrence of the blocked state at the discharge port.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a schematic configuration of an ash melting furnace in an embodiment of the present invention.

FIG. 2 is a plan view of a main part of an ash melting furnace in the example.

FIG. 3 is a sectional view taken along line DD of FIG.

FIG. 4 is a sectional view taken along line EE of FIG.

[Explanation of symbols]

 1 Ash Melting Furnace 2 Furnace Main Body 3 Bottom Wall 4 Preheating Side Bottom Wall 5 Melting Side Bottom Wall 5a Front Bottom Wall 5b Rear Bottom Wall 11 Preheating Chamber 12 Melting Chamber 21 Charge Port 22 Discharge Port 31 Heating Burner

Claims (1)

[Claims] 1. An ash melting furnace for heating and melting ash by a burner, the furnace body having a ash charging port formed at one end and a molten ash discharging port formed at the other end. The bottom wall of the furnace is inclined downward from one end side to the other end side, an ash preheating chamber is formed at a position near one end in the furnace body, and a heating burner is provided at a position near the other end. The melting chamber is formed, and the cross-sectional shape in the width direction of the portion near the inlet of the bottom wall on the melt chamber side is formed in a mountain shape, and the cross-sectional shape in the width direction of the portion near the outlet is formed in a valley. Ash melting furnace characterized by being formed into a shape.