JPS5841143B2 - Pressurizing device for pressurized pouring furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressurizing device for a pressurized pouring furnace in which molten metal is pressurized by gas and poured into a mold.

As shown in FIG. 1, the pressurized pouring furnace 1 communicates with a hot water storage tank 2 at the bottom, which is lined with a refractory material and whose upper open end is hermetically closed with a lid 3. It consists of a hot water inlet 4 and a hot water outlet 5.

In some cases, a groove-shaped induction heater 6 for heat retention and heating as shown in FIG. 2 is attached to the hot water storage tank 2.

In such a pouring furnace 1, the molten metal injected from the inlet 4 is held in the hot water storage tank 2, and heated and maintained at a predetermined temperature by the induction heater 6.

When pouring metal using such a pouring furnace, the pressure of the gas in the upper space of the pouring tank 2 is as shown in FIG. 3A.

Mouth, adjusted as shown in Ha.

That is, pressurized gas inside the hot water storage tank 2 is supplied from the supply/exhaust port 31 provided in the lid 3, and the pressure in the upper space of the hot water storage tank 2 is maintained at a predetermined pressure P.

The molten metal level in the hot water storage tank 2 falls by an amount commensurate with this pressure P, and the molten metal levels at the inlet 4 and outlet 5 rise.

[FIG. 3A] This pressure P is selected to a value such that the molten metal reaches a predetermined height that does not exceed the weir at the tap outlet 5.

Next, when gas is further supplied from the supply/exhaust port 31 for a predetermined period of time commensurate with the amount of hot water dispensed, and the pressure in the hot water storage tank 2 is increased by △P, the molten metal flows into the pouring port 5 as shown in Figure 3. The molten metal flows out from the pouring port 51 over the weir and is poured into a mold (not shown).

When stopping the hot water supply, open the supply/exhaust port 31 and remove the hot water from the hot water tank 2.
The pressurized gas inside is exhausted to return the pressure inside the hot water storage tank 2 to normal pressure.

[Go to Figure 3] In this way, by adjusting the pressure in the hot water storage tank 2 by supplying and discharging pressurized gas, this pouring furnace 1 is automatically adjusted.
Molten metal can be poured into the mold from the molten metal.

However, in such a pressurized pouring furnace, conventionally,
Most of the time, air was used as the pressurizing gas.

When air is used as a pressurizing gas in this way, the pressurizing gas contains oxygen, which oxidizes the molten metal and the various additives added to the molten metal for inoculation or component adjustment. Generates slag and consumes additives.

In this case, the inevitable problem is that the generated slag mixes into the molten metal and adheres to the inner wall of the runner of the induction heater 6 and the runner that connects the outlet 5 and the hot water storage 42, causing these runners to close. There is a risk that this may occur.

If the runner of the induction heater 6 is blocked, the molten metal cannot be kept warm, and if the runner of the tap outlet 5 is blocked,
Problems arise, such as the error in the amount of hot water being dispensed becomes large, making it impossible to pour hot water accurately.

In order to eliminate the above-mentioned drawbacks, this invention uses an inert gas as a pressurizing gas in the pouring furnace, suppresses the generation of slag, suppresses the consumption of additives, and is significantly more expensive than air. It is an object of the present invention to provide a pressurizing device for a pressurized pouring furnace that can suppress an increase in running costs of the pouring furnace due to the use of an inert gas.

This invention will be described in detail with reference to the embodiment shown in FIG.

The configuration of the pouring furnace 1 in FIG. 3 is the same as that shown in FIG. 1.

According to this invention, newly provided components include an inert gas replenishment cylinder 21, a surge tank 23 for storing inert gas compressed and pressurized by a compressor 22, and a hot water storage tank of the pouring furnace 1 from this surge tank 23. a pressure regulator 24 that adjusts the pressure of the inert gas supplied to the hot water tank 2 to control pouring; and an exhaust valve branched to the supply/exhaust port 31 to guide the inert gas in the hot water storage tank 2 to the exhaust tank 26. 25 and a filter 27 that cleans the exhaust inert gas in the exhaust tank 26 and guides it to the compressor 22.

Each of these elements is connected by a pipe to form one circulation path.

In the apparatus of the present invention, when pouring molten metal, the exhaust valve 25 is first closed, and the surge tank 23 is closed.
The inert gas stored under pressure is supplied to the pouring furnace 1 via the pressure regulator 24, and the pressure in the hot water storage tank 2 is set to a value P necessary to raise the molten metal level to a predetermined height at the tap outlet 5. Adjust to.

Next, inert gas is further supplied from the surge tank 23 to the pouring furnace 1 for a time commensurate with the amount of poured molten metal, and the pressure in the hot water storage tank 2 is increased to the level necessary for the molten metal to flow out over the weir of the tap outlet 5. Increase the pressure by △P.

When stopping pouring, the exhaust valve 25 is opened.

As a result, the inert gas in the hot water storage tank 2 is exhausted to the exhaust tank 26 via the exhaust valve 25, and the pressure inside the hot water storage tank 2 is released, so that the molten metal level at the tap outlet 5 is lowered and the molten metal is poured. will be stopped.

When the pressure in the hot water storage tank 2 becomes normal pressure, the exhaust valve 25 is closed again.

The inert gas exhausted into the exhaust tank 26 is sucked into the compressor 22 through the filter 27, compressed and pressurized, and stored in the surge tank 23 again, where it is reused as a pressurizing gas during the next pouring process. Ru.

Although the inert gas circulation path is constructed to be airtight, some of the inert gas leaks during the process of circulating through this circulation path, so inert gas replenishment is required to compensate for this leakage. A cylinder 21 is provided, which cylinder 21 is connected to the inlet of a compressor 22.

Thereafter, by repeating the same operation, pouring is automatically performed.

At this time, in the above-described pouring, the pressure applied within the hot water storage tank 2 is adjusted by the pressure regulator 24 in proportion to the amount of molten metal.

Therefore, the pressure inside the surge tank 23 is maintained at a sufficiently higher pressure than the above pressure to allow for the pressure reduction due to the supply of inert gas into the hot water storage tank 2 during pouring.

If the volume of the surge tank 23 is large and its pressure is high enough, the compressor 22 will not operate during one pouring.
Not only can the exhaust capacity be kept small even when the compressor 22 is operated, but the compressor 22 only needs to be operated once for several pressurizations.

Similarly, for exhaust, if the capacity of the exhaust tank 26 is large and its pressure is low enough, the compressor 22 only needs to be operated once for several times of exhaust, and these are the capacities of the known pressure reservoir and the capacity of the air machine. Selected based on relationship with

The cylinder 21 has a pressure of several tens of atmospheres to several hundreds of atmospheres depending on the type of inert gas, but it is provided with a known on-off valve and a pressure regulating valve (not shown), and its working pressure is several atmospheres.

The flow rate of the cylinder is generally much smaller than the required flow rate when pressurizing the hot water storage tank 2, so from that point of view, the surge tank 23
It is necessary to secure the capacity, that is, the flow rate, and similarly, an increase in the pressure of the exhaust cylinder 26 due to the flow of gas from the cylinder 21 is not a problem.

Rather, the pressure in the exhaust tank 26 is designed to be set by the compressor 22.

According to the apparatus of the present invention, since an inert gas is used as the pressurizing gas, the upper space of the hot water storage tank 2 of the pouring furnace is filled with the inert gas, and the molten metal in the hot water storage tank 2 is Oxidation is prevented.

Therefore, the generation of slag and the consumption of additives can be significantly reduced, making it possible to perform accurate pouring and maintain the molten metal with stable components.

In addition, the pressurized gas line was configured so that the exhaust gas and inert gas after pressurization are collected in the exhaust tank and reused, so the amount of inert gas consumed during operation is reduced by leakage during the yarn path. Since the amount is extremely small, running costs can be kept relatively low even if inert gas is expensive.

In addition, since nitrogen gas may have an adverse effect on cast iron etc. even if it is an inert gas, it is desirable to use an inert gas other than nitrogen gas.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing a pressurized pouring furnace used in this invention, Fig. 2 is a cross sectional view showing an induction heater attached to this pressurized pouring furnace, and Fig. 3 is a two-port and C is an explanatory diagram of the operation of a pressurized pouring furnace, and FIG. 4 is a schematic configuration diagram showing an embodiment of the present invention. 1: Pouring furnace, 2: Hot water storage tank, 3: Lid, 4: Inlet, 5: Outlet, 21: Inert gas supply cylinder, 22: Compressor, 2
3: surge tank, 24: pressure regulator, 25: exhaust valve, 26: exhaust tank, 27: filter.

Claims (1)

[Claims] 1 The upper space of a hot water storage tank equipped with a hot water inlet and a hot water outlet is sealed, this space is pressurized with pressurized gas, and the molten metal stored in the hot water storage tank is poured into a mold from the hot water tap. In a pressure-type pouring furnace, an inert gas is used as pressurized gas, a surge tank is used to pressurize and store this inert gas, and the pressure of the inert gas to be supplied from the surge tank to the hot water storage tank is adjusted. A pressurization adjustment device that controls the amount of hot water poured, an exhaust tank that recovers pressurizing inert gas in the hot water storage tank via an exhaust valve, and compresses the inert gas in the exhaust tank and stores it in the surge tank. A pressurizing device for a pressurized pouring furnace, characterized in that a pressurizing inert gas circulation path is formed by a compressor, and the pressurizing inert gas is circulated and used.