JPS635663B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a metal melting furnace for melting metals such as aluminum and iron, particularly recovered metal waste, for recycling.

[Conventional technology]

Conventionally, there are two types of melting furnaces for melting aluminum waste: one is to heat an iron kettle and melt the aluminum waste in it, and the other is to put the aluminum waste into the furnace and direct the combustion gas from the burner to the aluminum waste. There was one that had to be sprayed on to dissolve it.

[Problem that the invention seeks to solve]

However, in the former case, the iron content liberated from the iron kettle contaminates the recycled aluminum and reduces its purity, while in the latter case, it is not possible to dissolve a large amount of aluminum waste at the same time. Another drawback was that the recycled aluminum was forcibly oxidized by the combustion gas, producing a large amount of oxides.

In order to eliminate such drawbacks, the applicant first put metal waste into a melting tank made of non-metallic refractories such as castable refractories, and indirectly melted the metal waste through this melting tank. Make sure to heat the
In addition, such a melting tank is installed in a heat storage type heat insulation chamber, and a heating space is formed between the bottom wall of the melting tank and the inner bottom surface of the heat insulation chamber, and a vertical flame path is formed on the side wall of the melting tank, and a heating space is formed between the bottom wall of the melting tank and the inner bottom surface of the heat insulation chamber. By guiding the combustion gas generated in the above-mentioned heating space and from there to the flame duct, the metal waste in the melting tank can be heated and melted with high thermal efficiency, and the metal waste can be heated and melted in the heat-insulated chamber above the melting tank. In addition, he invented a device with a preheating chamber for accommodating raw materials, and is currently applying for a patent as Japanese Patent Application No. 59-40290, but it was found that this method had the following problems.

It is not always easy to form a flame channel on the side wall of the melting tank.

Because a space for preheating the raw materials is provided above the melting tank, the height of the furnace (height of the insulation chamber) increases, increasing construction costs.

When repairing or replacing the melting tank, the preheating chamber must be removed and rebuilt.

The present invention was proposed to solve these problems.

[Means for solving problems]

The upper and lower sides of the heat storage type heat insulation chamber in which the melting tank is installed, that is, the upper heating space above the melting tank and the lower heating space below the melting tank, are connected to the inner wall surface of the heat insulation chamber and the outer periphery of the melting tank. A raw material hopper is constructed outside the circumferential side of the upper heating space, communicating through a flame guide path provided in between, and a communication port with the raw material hopper is provided in a part of the heat insulating wall that surrounds the upper heating space. A metal melting furnace that is equipped with a shutter that can be opened and closed at this communication port.

[Effect]

According to the present invention, it is easy to install a flame guiding path that communicates the upper and lower heating spaces, and the raw material hopper is constructed outside the circumferential side of the upper heating space, and its communication port is connected to a part of the heat insulating wall. When repairing or replacing the melting tank, the top plate of the heat insulating chamber can be removed, the melting tank can be lifted upwards, and the tank can be easily taken out.

〔Example〕

Generally speaking, the metal melting furnace of the present invention includes a melting tank b with an open top surface built in a heat storage type heat insulating chamber a, and a raw material hopper c built outside the circumferential side of the upper heating space of the heat insulating chamber a. In addition, a solid fuel combustion device d installed outside the insulation chamber a is connected to the lower heating space of the insulation chamber a, and a hot water stirrer e is suspended from the upper heating space.

The heat storage type insulation room a has a foundation in which a concrete layer 1, a sand layer 2, a castable refractory layer 3 (e.g. a mixture of alumina or syamoto aggregate and hydraulic cement, the same applies hereinafter), and a brick layer 4 are laminated in order. A heat storage type heat insulating wall consisting of a brick inner wall 5, a castable refractory layer 6, a concrete wall 7, a castable refractory piece 8, a steel plate 9, etc. is installed on the top of It is constructed by closing with a top plate g provided with a material layer 11.

The melting tank b is constructed by covering the outer peripheral surface of the castable refractory wall 12 with an iron plate 13,
It is supported horizontally on a castable refractory column 14 in the internal space of the melting tank b, and an upper heating space _h1 is defined between the upper surface of the melting tank b and the top plate g. The lower surface and the upper surface of the foundation f, that is, the insulation room a
A lower heating space _h2 is defined between the inner bottom surface and the inner bottom surface of the lower heating space h2.

Most of the upper surface of the surrounding cavity _h3 formed between the outer periphery of the melting tank b and the inner wall surface of the heat insulation chamber a is closed with iron plates, but there are flame guide paths 1 at the four corners.
By providing 5, the upper and lower heating spaces _h1 and
_h2 is communicated through the above-mentioned surrounding space _h3 .

The raw material hopper c is formed and installed within the heat insulating wall constituting the heat insulating chamber a and outside the peripheral wall of the upper heating space _h1 . One side of the bottom of the hopper c communicates with the upper heating space _h1 through a communication port 16 provided in the heat insulating wall. Also, communication port 1
6 is equipped with a shutter 17 made of iron plate suspended by a hanging wire 17' so as to be openable and closable. Normally, the communication port 16 is closed by this shutter 17, and the raw material (material to be melted) in the hopper c is passed through the shutter 17. Preheat.

To feed the raw material into the hopper c, open the top opening 1.
This is done by opening the cover plate 19 of 8. Furthermore, by opening the shutter 17, the raw material in the hopper c is fed to the melting tank b.

The solid fuel combustion device d is for feeding flame to the lower heating space _h2 , and has the following configuration.

Reference numeral 20 denotes a combustion chamber surrounded by a fireproof structure wall, in which a blow pipe 22 is installed on the upper side of the rear wall 21, and a screw feeder 23 is installed directly below the blow pipe 22. The nozzle 22' of the blast pipe 22 is located opposite to the flame path 25 that opens on the upper side of the front wall 24, and
The screw feeder 23 has its inner end 23' located relatively close to the rear wall 21.

Reference numeral 26 denotes an air supply pipe which is supported through the front wall 24 and the rear wall 21 so as to be rotatable from front to back, and which is hung horizontally at the bottom of the combustion chamber 20. The required drive source and forced air supply source are connected to the outer end of the pipe. A large number of air supply holes 27 are provided in the area located within the chamber 20 . Further, this air supply pipe 26 is connected to the same area as above, that is, the inner surface of the front wall 24 and the rear wall 21.
A feeder screw 28 is provided between the inner surface and the inner surface of the feeder screw 28.

29 is an ash chamber provided at the bottom front side of the combustion chamber 20,
An impeller 31 is installed within the funnel-shaped bottom 30, and the rotation of the impeller 31 causes ash to be discharged through the ash discharge port 32.

Bulk solid fuel in the combustion hopper 33 (for example,
Compressed waste paper and cutting it into blocks with a diameter of several centimeters, ogalite, coal, etc.) are automatically supplied to the combustion chamber 20 by the screw feeder 23, and from its inner end 23', the air supply pipe 26 It falls toward the base 28' of the feeder screw 28, and during this fall, it is ignited by the hot air and flame inside the combustion chamber 20.
While continuing combustion, the air is transferred to the front, that is, to the ash chamber 29 side, and during this time, the air supplied from the air supply hole 27 and the
The completely combusted flame and combustion gas are guided to the flame path 25 by the air blown from the second nozzle 22'.

In the above, the first ignition of the fuel supplied to the combustion chamber 20 by the screw feeder 23 is performed through an ignition window (also not shown) while opening an exhaust valve (not shown) to exhaust the fuel. . Note that the installation of the blower pipe 22 may be omitted.

The fuel in the combustion chamber 20 is combusted while being transferred to the impeller 31, which is an ash discharge mechanism, by a feeder screw 28 provided in the air supply pipe 26. The ash is also transferred in the same way as fuel without burying the air supply pipe 26, and is reliably discharged, so that the air supply pipe 26 is not buried in ash and cannot be supplied with sufficient air, or it is clogged with clinker. There is no risk that the ash will be discharged incompletely. Therefore, the best combustion condition can always be obtained.

The flame in the combustion chamber 20 enters the flame path 25 and is transmitted to the lower heating space _h2 through the flame introduction path 25' communicating with the lower heating space _h2 .

As a result, the bottom and outer circumference of the melting tank b are first heated to melt the raw materials in the tank, but the flame is guided to the upper heating space _h1 through the flame guide path 15 and melts. The raw material in tank b is directly heated from its upper surface to further proceed with melting.

2, numeral 33 is an insulating door that can be opened and closed in a viewing hole 34 provided in a part of the insulating wall surrounding the upper heating space _h1 , and 35 is an auxiliary burner installed in the insulating door 33. The nozzle 35' is positioned to penetrate into the upper heating space _h1 . In FIGS. 1 and 2, 36 is a flue provided in a part of the heat insulating wall surrounding the upper heating space _h1 , and 37 is a hot water outlet.

Next, the hot water stirrer e has a stirring plate 39 diagonally installed in a rectangular frame 38 that is similar in shape to the inner bottom of the melting tank b and is a little smaller than that, and has four stirring plates installed at the four corners of this rectangular frame 38. A support 40 is inserted into and out of the top plate g of the heat insulation chamber a, and its upper ends are connected by a horizontal beam 41.

The hot water stirrer e is suspended from an electric chain block (not shown), and normally the rectangular frame 38 is hoisted to a position close to the top plate g of the upper heating space _h1 , but if necessary, this may be suspended. The material in the dissolving tank b is moved up and down as appropriate to stir the raw materials in the dissolving tank b so that the raw materials in the dissolving tank b are evenly and uniformly dissolved.

〔Effect of the invention〕

As is clear from the above, according to the present invention, the raw materials in the melting tank are heated and melted by the flames (and combustion gas) in the upper and lower heating spaces, and the flames first flow into the lower heating spaces. In order to introduce the flame through the flame introduction path and guide it to the upper heating space, we installed the guide path between the outer periphery of the melting tank and the inner wall of the heat-insulating chamber in which the melting tank is installed. The guide path is easier to install than the case where the guide path is formed in the side wall of the melting tank, and since the raw material hopper is mounted outside the circumference of the upper heating space, the raw material hopper can be placed in the upper heating space. Unlike when the furnace is installed above, there is no need for the height of the insulation chamber or problems with taking it out of the insulation chamber when repairing or replacing the melting tank, making the construction of the furnace extremely economical. It can be done in a specific manner.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention.
The figure is a longitudinal sectional view, Fig. 3 is a plan view of the melting tank, Fig. 4 is a longitudinal sectional view of the main part showing how the top plate of the support of the hot water stirrer penetrates, and Fig. 5 is a longitudinal sectional view of the solid fuel combustion device. It is a diagram. a... Heat storage type insulation room, b... Melting tank, g... Top plate, h ₁ ... Upper heating space, h ₂ ... Lower heating space,
36... Flue, 25'... Flame introduction path, 15...
Flame guideway, c...raw material hopper, 16...communication port, 17...shutter.

Claims (1)

[Claims] 1. A melting tank is provided in a heat storage type heat insulation chamber, and the space between the top of the melting tank and the top plate of the heat insulation chamber is an upper heating space, and the space between the lower surface of the melting tank and the inner bottom of the heat insulation chamber is a lower heating space. A flue is connected to the upper heating space, a flame introduction path is connected to the lower heating space, and the upper and lower heating spaces are provided with a flame guiding path between the inner wall surface of the heat insulating chamber and the outer periphery of the melting tank. A raw material hopper is installed outside the circumferential side of the upper heating space, and a communication port with the raw material hopper is provided in a part of the heat insulating wall that surrounds the upper heating space. A metal melting furnace characterized by being equipped with a flexible shutter.