JPS589913B2 - Metal or non-metal molten metal heat retention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a molten metal or non-metallic metal holding furnace, particularly in a lead furnace, an aluminum furnace, or a zinc furnace, when the main heat supply source is temporarily stopped, and when the molten metal is temporarily or continuously This invention relates to a heating device for molten metal or non-metal that is primarily intended for emergency use in the event of excessive temperature rise.

Figure 1 shows a longitudinal cross-sectional view of an example of the structure of a holding furnace, in which 1 is a molten metal, 2 is a container, 3 is an inductor (including a coil), and 4 is an iron plate (workpiece). 4 is continuously immersed in molten zinc 1 to produce a galvanized iron plate.

In the conventional method, when the supply of thermal energy to the inductor 3 is stopped due to an accident that occurs during normal operation, such as a power outage or a malfunction of the inductor (including the coil) 3, if the molten metal 1 solidifies over time, the entire holding furnace is Since it would become unusable and cause enormous damage, the surface of the molten metal 1 was heated directly with a combustion burner or the like to prevent the molten metal from solidifying.

Furthermore, in the inductor system, power cannot be supplied to the inductor 3 in the event of a power outage, so an expensive emergency generator has been unavoidably installed.

The disadvantage of the method of heating the molten metal 1 directly above the surface of the molten metal 1 with a combustion burner or the like is that a large-scale combustion burner must be installed above the surface of the molten metal 1.

It is difficult to uniformly heat the entire molten metal 1 and local heating, that is, extreme temperature unevenness occurs, so that a crank is likely to occur in the container 2.

A large amount of metal oxide evaporates or floats on the surface of the molten metal 1, resulting in severe loss of raw materials.

Maintenance of container 2 and inductor 3 while heating with combustion burner
It was impossible to repair.

Furthermore, if the iron plate (work) 4 is continuously annealed or the preheating temperature of the iron plate (work) 4 is too high, the molten metal 1
It is necessary to lower the temperature of the iron plate (work) 4, but conventional methods involve either leaving it naturally and waiting until the temperature reaches the appropriate temperature, adding cold raw materials, or lowering the temperature of the iron plate (work) 4.

Moreover, all of the above cases needed to be dealt with urgently and quickly, and it was also necessary to have personnel and equipment on standby at all times.

As mentioned above, the conventional holding furnaces had serious defects in terms of accident prevention, but according to the present invention, all of the above-mentioned defects in the event of an accident can be eliminated.

2 to 5 show an embodiment of the present invention.

FIG. 2 is a longitudinal cross-sectional view of one embodiment showing the state of use of the present invention, in which 1 is a molten metal, 2 is a container, 3 is an inductor (including a coil), 4 is an iron plate (work), and 5 is a box body. This is a heat exchanger having the shape of a molten metal heat retaining device of the present invention.

If an accident occurs in the molten metal 1, the container 2, or the inductor (including the coil) 3, and the molten metal 1 needs to be heated, kept warm, or cooled, the molten metal warming device 5 is used to cover most of the surface of the molten metal 1. The temperature of the molten metal 1 is raised, kept warm, or lowered by installing it in a similar manner.

FIG. 3 is a cross-sectional view of an embodiment of the heat exchanger 5 equipped with a combustion burner device, which is a specific example of the molten metal heat retention device 5, in which 6 is a heat insulation box, 7 is a combustion burner, and 8 is a heat transfer Plate and bottom plate distortion prevention plate, 9 is graphite paint, 10 is chimney, 11 is hanging hand, 1
2 indicates a heat insulating material or a heat reflecting material.

The combustion burner 7 is arranged to heat the bottom plate of the heat insulation box 6, and the combustion gas heats the bottom plate of the heat insulation box 6 and is discharged to the outside from the chimney 10.

The heat insulation box 6 has a tunnel shape, which makes the combustion flame more effective.

In addition, the area of the bottom plate of the heat-insulating box 6 is large enough to cover most of the surface area of the molten metal 1, and since it is box-shaped as a whole, it sinks a little on the surface of the molten metal 1 by itself due to Archimedes' principle. floating in the state.

Therefore, the area where the molten metal 1 comes into direct contact with the air becomes small, which improves the heat retention of the molten metal 1 and improves the heat retention of the molten metal 1.
Since oxidation on the surface of the molten metal 1 can be prevented, there is a significant reduction in floating and consumption of the molten metal 1, resulting in fewer bills and a great advantage in terms of raw material yield.

Furthermore, even if the bottom plate of the heat insulation box 6 is directly exposed to the combustion burner flame, since the bottom plate of the heat insulation box 6 is submerged in the molten metal 1, the thermal energy is quickly transferred to the molten metal by flame transfer, and the heat energy is quickly transferred to the molten metal.
Since the bottom plate is kept at a low temperature without being overheated or significantly oxidized, it has the advantage that a thin plate can be used without increasing the plate thickness.

Furthermore, since the molten metal 1 is not directly exposed to the combustion burner flame and is heated via the heat insulating box 6, uniform heating is possible.
Another advantage is that no crank occurs.

In order to improve thermal efficiency, the heat source can be made smaller by installing a heat insulating material or a heat reflecting material 12 on the inner upper surface and inner side surface of the heat insulating box 6.

The heat transfer plate/bottom plate distortion prevention plate 8 is integrated with the bottom plate of the heat insulation box 6, and has a structure that improves thermal efficiency by increasing the heat transfer area and prevents thermal deformation of the bottom plate of the heat insulation box 6.

The heat insulating box 6 is usually made of an iron plate, but since the contact surface between the iron plate and the molten metal 1 is corroded by a chemical reaction, a graphite-based paint 9 is applied to the surface that will come into contact with the molten metal 1. The structure is designed to provide protection.

FIG. 4 shows another embodiment of the molten metal heat retention device according to the present invention, and is a cross-sectional view of the embodiment equipped with an electric resistance heating element, and the method of use is different from that in FIG. 3 only in the heat source. However, the benefits and losses are the same.

That is, 6 is a heat insulating box, 8 is a heat transfer plate/bottom plate distortion prevention plate, 9 is a graphite paint, 11 is a hanger, 12 is a heat insulating material or a heat reflective material, 1
3 is a lead outlet, 14 is an electric resistance heating element, and 15 is a valve or pressure regulator.

An electric resistance heating element 14 is attached to the bottom plate of the heat insulation box 6, and the bottom plate is heated.

Power is supplied from the lead outlet 13.

A valve or pressure regulator 15 is used to adjust the pressure of the gas within the heat box 6 due to temperature changes.

FIG. 5 shows still another embodiment of the molten metal heat retention device according to the present invention, which is equipped with an inlet and an outlet for hot air or cold air.

In this case as well, only the heat source is different from those in FIGS. 3 and 4, and the method of use and advantages and disadvantages are generally the same, but this is particularly suitable for cooling or keeping the molten metal 1 warm.

That is, 6 is a heat insulating box, 8 is a heat transfer plate/bottom plate distortion prevention plate, 9 is a graphite paint, 11 is a hanger, 12 is a heat insulating material or a heat reflective material, 1
6 indicates a hot air inlet or a cold air inlet, and 17 indicates a heat outlet or a cold air outlet.

When heating or keeping the temperature of molten metal 1, hot air population 16
Hot air is caused to flow in to heat the bottom plate of the heat insulation box 6, and the hot air is discharged from the hot air outlet 17.

When cooling or retaining the temperature of the molten metal 1, use the cold air inlet 16.
The molten metal 1 can be cooled or kept warm by flowing gas whose temperature is lower than that of the molten metal 1, cooling the bottom plate of the heat insulation box 6, and letting the gas flow out from the cold air outlet 17.

That is, it is used when the workpiece is continuously annealed or when the preheating temperature of the workpiece is too high.

It goes without saying that the structure shown in FIG. 5 can be manufactured by overlapping the structures shown in FIGS. 3 and 4.

Furthermore, in the above explanation, only molten metals have been explained, but the operation is not limited to this, even non-metals can be operated in a molten state.

It goes without saying that the present invention is similarly applicable to glass, refractories, etc., for example.

As described above, according to the molten metal heat retention device of the present invention, it is possible to deal with power outages, inductor accidents, etc., which are considered to be the weak points of holding furnaces, with peace of mind, and also to prevent wear and tear due to oxidation of raw materials. Significant reduction in waste removal work, no need to install an emergency generator, no cracking or damage to the refractory container as the combustion burner flame does not directly hit the refractory container, inductor repair and coil maintenance while keeping the molten metal warm. Replacement gives rise to the advantage of having multiple dogs in town performances, etc., and contributes to the spread of holding furnaces.

[Brief explanation of the drawing]

Fig. 1 is a schematic sectional view showing the structure of a holding furnace, Fig. 2 is a schematic sectional view showing the state of use of the present invention, Figs. 3, 4, and 5.
Each figure is a schematic sectional view of a molten metal heat retention device according to an embodiment of the present invention. In the figure, 1 is a molten metal, 2 is a container, 3 is an inductor, 4 is a workpiece, and 5 is a heat exchanger. Note that the same reference numerals in the drawings indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. In a holding furnace for keeping molten metal or non-metallic metal warm, in which the heat source during normal use is supplied by an inductor, a box-shaped heat exchanger containing a heat source inside is connected to the molten metal. A molten metal or nonmetallic metal heat retention device, characterized in that it is placed floating so as to cover most of the surface of the metal or nonmetal. 2. The molten metal or non-metal heat retention device according to claim 1, wherein the heat source housed in the heat exchanger is an electric resistance heating element. 3. The molten metal or nonmetallic metal heat retention device according to claim 1, wherein the heat source accommodated in the heat exchanger is a burner. 4. The molten metal or non-metal heat retention device according to claim 1, characterized in that the heat source is obtained by flowing a heat medium into and out of a heat exchanger.