JPS595823Y2 - Reverberatory furnace molten metal stirring device - Google Patents

Description

[Detailed description of the invention] This invention is a main element of a molten metal stirring device installed in a reverberatory furnace that controls the molten metal by transmitting the heat generated by the flame of a burner or the like to the fixed metal to be melted or the molten metal obtained by melting the fixed metal. The present invention relates to the structure of a fireproof tube for an electromagnetic pump and its joining means.

For example, it is known that stirring the molten aluminum produced in the melting process of an aluminum reverberatory furnace provides numerous metallurgical benefits.

That is, stirring of the molten metal in the reverberatory furnace is required in order to make the temperature distribution uniform, to make the chemical composition uniform, and to improve the energy efficiency of the reverberatory furnace.

This effect is achieved by providing an external flow path in one part of the flow path for the circulating flow of molten metal in the reverberatory furnace as a circulating flow means for stirring in one of the drawing devices, and applying a thrust force that promotes the circulating flow of the molten metal in this external flow path. There is a method of installing an electromagnetic pump that provides

The basic structure of this method is shown in Figure 1.

That is, in FIG. 1, 1 is a reverberatory furnace into which solid metal such as aluminum ingots and aluminum alloys is supplied, and the solid metal is directly melted and melted by the generation of heat from a heating device (not shown). The high-temperature molten metal obtained by heating the molten metal comes into contact with the periphery of the solid metal, gradually increasing the amount of molten metal.

Molten metal flow paths 2 and 3 are made of troughs or pipes, and one end of each is connected to both ends of the reverberatory furnace 1 separated by an appropriate distance.

Reference numeral 4 designates an electromagnetic pump, the refractory tube of which is arranged so that the longitudinal direction of its cross section is horizontal in order to increase efficiency regardless of the level of molten metal in the reverberatory furnace 1. The end not connected to the furnace 1 is connected.

When AC power is supplied to the moving magnetic field generating inductor of the electromagnetic pump 4, a flow of molten metal is generated in the flow paths 2, 3 and the external flow path formed from the refractory tube of the electromagnetic pump 4, and the reverberant furnace 1 The molten metal inside is subjected to stirring action, and the low-temperature molten metal around the metal to be melted (unmelted aluminum ingot, etc.) is exchanged with other high-temperature molten metal, and the temperature of the entire molten metal is equalized and fed to the reverberatory furnace 1. absorbs heat energy.

In the process of stirring the molten metal, the wall thickness of the electromagnetic pump refractory tube whose molten metal introduction hole cannot be maintained is thinner than the flow paths 2 and 3 due to electromagnetic efficiency. Therefore, its service life is significantly shorter than that of the flow paths 2 and 3 connected to it, and there is a risk that cracks will occur when the electromagnetic pump fireproof tube reaches the end of its life. The connected channels 2 and 3 expand due to the heat from the molten metal, which applies stress to the fireproof tube of the electromagnetic pump 4, and especially the channels 2 and 3.
A crack appeared at the joint between the electromagnetic pump 4 and the fireproof pipe, and there was a great possibility that the hot water would leak from this crack.

The purpose of this invention is to prevent the outflow of molten metal from the electromagnetic pump fireproof tube by surrounding the outer periphery of the electromagnetic pump fireproof tube with stainless steel material and providing water cooling means on the outer periphery of the joint surface with the flow path at both ends of the fireproof tube. It is in.

The illustrated embodiment will be specifically described below.

Fig. 2 is a sectional view specifically showing the parts related to the present invention in Fig. 1, and Fig. 3 is a sectional view taken along line AA in Fig. 2. In each figure, 4a is a fireproof pipe for an electromagnetic pump. , its both end surfaces are connected to the ends of the channel-shaped troughs 2 and 3 via a stress absorbing material K such as refractory fiber or refractory mortar that has the function of absorbing a certain degree of thermal stress.

4b is a stainless steel case that surrounds the outer periphery of the fireproof tube 4a.

4C1 and 4C2 are flanges provided at both ends of the electromagnetic pump fireproof tube 4a, which are opposed to the flanges 2a and 3a provided at each end of the flow paths 2 and 3, respectively, and are fixed by bolts L, and are fireproof. The connection between the pipe 4a and the channels 2 and 3 is maintained.

4cL and 4dz are inductors for generating a moving magnetic field, and the fireproof tube 4a
It is provided facing both the upper and lower sides of the stainless steel case that surrounds it.

M1 to M4 are water channels, each flange 3a, 4C2, 4C1
, 2a are arranged along the periphery of the refractory pipe 4a or the areas close to the end faces of the flow channels 2 and 3, and provide constant water circulation, especially at the joint surfaces between the refractory pipe 4a and the flow channels 2 and 3. It absorbs heat.

In the structure of the above embodiment, when AC power is supplied to the inductors 4d1 and 4dz to generate a moving magnetic field in the direction of the arrow Y, the molten metal in the refractory tube 4a moves to the flow path 3, and as a result, the molten metal flows simultaneously. The molten metal existing in channel 2 enters refractory pipe 4a.

Therefore, the molten metal is forcibly transferred from the flow path 2 to the flow path 3, resulting in a stirring action of the molten metal.

During this process, cracks occur in the fireproof tube 4a of the electromagnetic pump 4, and the molten metal flows through the cracks into the stainless steel case 4.
Even if b is reached, the molten metal will solidify before being damaged by the molten metal due to the inherent properties of stainless steel material, ie, its high melting point, and the danger of the molten metal leaking out can be prevented.

Furthermore, since the stainless steel case 4b is made of a non-magnetic material, there is no risk of closing a short circuit of the magnetic flux supplied from the inductors 4d1 and 4d2, and there is no room for vibration due to an alternating magnetic field.

Furthermore, the case material surrounding the refractory tube 4a should be limited to stainless steel because stainless steel has low electrical conductivity and can improve the efficiency of electric power applied to the molten metal.

On the other hand, when the flow paths 2 and 3 expand and contract based on the heat fluctuations in the flow paths 2 and 3, a gap is formed at the joint surface between the refractory tube 4a where the stress absorbing material K exists and the end surface of the flow paths 2 and 3. occurs, and molten metal often enters here.

However, the molten metal that has entered this gap flows through waterways M1 to M
The heat is strongly removed by the water passing through 4, solidifying it and preventing further intrusion of molten metal.

As described above, the molten metal stirring device according to the present invention is provided with separate channels for receiving and receiving molten metal from two locations separated by an appropriate distance from the reverberatory furnace, and the free end of each channel is not connected to the reverberatory furnace. In a structure in which an electromagnetic pump is interposed between the parts and the molten metal stirring action is performed based on the operation of this electromagnetic pump, the outer periphery of the electromagnetic pump fireproof pipe except for the joint surface with the flow path is surrounded by stainless steel material,
Water cooling means is provided along the outer periphery near the joint surface between the end face of each flow path and the electromagnetic pump fireproof tube.

Based on this structure, the molten metal flowing through the cracks can be easily cracked by the water cooling action, especially at the joint surface between the fireproof pipe and the flow path, where cracks are likely to occur due to expansion and contraction of the flow path or electromagnetic pump refractory pipe due to temperature changes. It has solidified and there is no risk of it leaking outside.

On the other hand, the thickness of the electromagnetic pump refractory tube is limited from the viewpoint of electromagnetic efficiency, so the electromagnetic pump refractory tube is easily damaged. Therefore, leakage is reliably prevented, and since stainless steel is a non-magnetic material, there is no possibility of vibration caused by the moving magnetic field from the inductor, and since it does not affect the magnetic path, the thrust due to short circuit of the magnetic path is reduced. There is a practical benefit that does not deteriorate.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a molten metal stirring device for a reverberatory furnace embodying the present invention, FIG. 2 is a sectional view of a main part in FIG. 1, and FIG. 3 is a sectional view taken along line AA in FIG. 1... Reverberatory furnace, 2, 3... Channel, 4.
...Electromagnetic pump, 4a...Fireproof pipe, M1
~M4... Conduit.

Claims (1)

[Scope of utility model registration request] The molten metal is transferred from two places separated by an appropriate distance in the reverberatory furnace, and the molten metal in the refractory tube is used as a secondary conductor, and the moving magnetic field from the inductor placed between the refractory tubes is used. In a construction in which an electromagnetic pump is provided to provide thrust to the molten metal, and the electromagnetic pump refractory tube is connected between the free ends of the respective flow paths on the side not connected to the reverberatory furnace, both ends of the electromagnetic pump refractory tube are excluded. A molten metal agitation device for a reverberatory furnace, characterized in that the outer periphery is covered with a stainless steel material, and a water cooling means is provided around the periphery near the joining surface of a refractory tube and a flow path.