JPH0413598Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a nozzle opening structure for a molten metal stirring device.

(Prior Art) In a furnace for melting metals such as aluminum, copper, and zinc, if the molten metal is not stirred, the melting time becomes longer, the temperature to be heated becomes higher, and the amount of oxides generated increases. Therefore, by stirring the above molten metal, both the amount of oxide generated and the melting time can be reduced by approximately 10%.
It is recognized that it can be reduced.

FIG. 3 is a block diagram of a known mechanical stirring device. In the figure, an intermediate body 3 made of a refractory material and having a nozzle 2 therein is provided at the bottom of a melting furnace 1, and a pump cylinder 4 whose inner wall is lined with a refractory material is attached to the intermediate body 3. The pump cylinder 4 communicates with the inner bottom of the melting furnace 1 through the nozzle 2, and the upper end of the pump cylinder 4 is provided with an automatic switching valve 5 between outside air and negative pressure, a cyclone 6, a filter 7, etc. in the middle. It is connected to a vacuum blower 9 by an intervening vent pipe 8. The vacuum blower 9 has a motor 1
0, the molten metal is sucked into the pump cylinder 4 by vacuum negative pressure, and after a certain period of time, the automatic switching valve 5 is switched to introduce outside air into the cylinder. Since the vacuum suction force was removed and outside air was introduced, the molten metal sucked up into the pump cylinder 4 returns to the melting furnace 1 by its own weight, causing convection in the molten metal staying in the furnace, and the inside of the melting furnace 1 Stirred.

(Problem to be solved by the invention) After the melting process, for example, molten aluminum is discharged leaving a predetermined amount in the melting furnace 1, new coolant is added to the furnace, and the suction of the pump cylinder 4 is carried out.
Consider the case where the dispensing work is restarted. When cold material is added into the melting furnace 1, the surface melt inside the furnace is approximately
Even though the temperature is close to 1000℃, a part of the refrigerant has a temperature of 50℃.
There are large temperature fluctuations, such as around ℃. When the pump cylinder 4 starts operating, the cold material flows into the pump cylinder 4.
The temperature rises due to the molten metal discharged from the tank, promoting melting. At the same time, the temperature of the molten metal in the melting furnace 1 is also made uniform due to the wave effect of the molten metal. For this reason,
From the perspective of melting the cold material quickly, it is possible to suppress the energy loss of suction molten metal, increase the stirring efficiency, and
It is desirable to start operating the pump cylinder 4 at an early point in time.

However, at this early point in time, the molten metal level in the furnace is not much higher than the opening 2a of the nozzle 2 formed in the furnace wall so that its lower edge is flush with the hearth surface. If the above molten metal level is at opening 2
When the temperature is lower than a, there is a problem in that the air in the furnace is sucked into the pump cylinder 4 in addition to the molten metal, and this sucked air oxidizes the molten metal in the pump cylinder 4.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention has an aim that the opening area of the opening 2a of the nozzle 2 formed on the wall surface of the melting furnace 1 is smaller than that of the lower end surface of the pump cylinder 4. The cross-sectional area of the opening 2a is equal to the cross-sectional area of the opening, and the lower edge of the opening 2a of the nozzle is flush with the hearth surface, and the shape of the opening 2a is such that the depth direction dimension of the melting furnace 1 is larger than the width direction dimension. In addition to being selected to be short, this nozzle is configured to have a horizontal nozzle portion that is sufficient to discharge the molten metal in a horizontal direction and that is shorter than the thickness of the furnace wall, and an inclined nozzle portion that communicates with the pump cylinder. It is characterized by

(Function) The present invention has the above-described structure, and the nozzle opening 2a is formed so that the lower edge is flush with the hearth surface.
The depth dimension of the melting furnace 1 is shorter than the diameter of the conventional perfectly circular nozzle opening, and the opening area is the same as that of the conventional method. Therefore, in the present invention, the level of molten metal that sucks air in addition to the molten metal in the melting furnace 1 is lower than that in the conventional method, so the pump cylinder 4
starts operating faster.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Figure 1 is a diagram of a nozzle communicating with the melting furnace according to this embodiment, where Figure A is a vertical front view, Figure B is a sectional view taken along straight line 20-20 in Figure A, and Figure C is a straight line 21 in Figure A.
-21, FIG. 2A is a longitudinal sectional front view of the pump cylinder, and FIG. 2B is a plan view of the pump cylinder. Note that in FIGS. 1 and 2, parts that are the same as those in FIG. 3 showing the configuration of the conventional system are given the same reference numerals.

As shown in FIG. 2, the hollow hole 4a of the pump cylinder 4 that sucks up and discharges the molten metal has a constant perfect circular cross-sectional shape from the upper end 4b to the lower end 4c. On the other hand, as for the nozzle 2, as shown in FIG. As shown in FIGS. A and B, the melting furnace 1 has a rectangular shape, and the depth dimension L of the melting furnace 1 is shorter than the width dimension M. On the other hand, the opening 2b on the lower end surface of the pump cylinder 4 of the nozzle 2 is
As shown in FIG. 1C, it is a perfect circle, and the area of this perfect circle is the same as the cross-sectional area of the opening 2a and the cross-sectional area of the hollow hole 4a of the pump cylinder 4 shown in FIG. It has an area. Therefore,
The nozzle 2 has a rectangular cross section at the opening 2a, and extends from the opening 2a to the opening 2b in the lower end face of the pump 4.
The shape is transformed from the rectangular shape to a perfect circle with a gentle curve up to the curved portion 2c.

Next, the operation will be explained. The cold material in the melting furnace 1 is melted by the stirring action, and the molten metal is discharged from the furnace leaving a predetermined amount that is enough to fill the opening 2a of the nozzle 2 in the furnace, and new cold material is poured into the melting furnace 1. added to.
Next, the motor 10 is started to operate the pump cylinder 4.
A vacuum is created inside the melting furnace 1, and a small amount of the molten metal in the melting furnace 1 is sucked up into the pump cylinder 4 so that the level of the molten metal is higher than the opening 2a of the nozzle 2, and then discharged. By repeating this stirring operation, the cold material in the furnace is bathed in the discharged molten metal, which promotes melting and equalizes the temperature of the molten metal in the furnace.

Further, the nozzle 2 draws a gentle curve from the rectangular opening 2a to the curved part 2c of the nozzle to have a perfect circular cross section, and then maintains a perfect circular shape until the opening 2b of the lower end face of the pump cylinder 4. Moreover, since this perfect circle has the same area as the hollow hole 4a of the pump cylinder 4, there is no difference in stirring action from the case where the opening of the conventional system is a perfect circular nozzle.

In this embodiment, the opening 2a of the nozzle is formed into a rectangular shape having the same area as a perfect circle and a small depth, but is not limited to this. For example, the shape may be an ellipse whose size is smaller than the diameter of a perfect circle.

(Effects of the invention) As explained above, the present invention has the area of the opening of the nozzle communicating with the pump cylinder, which is formed on the furnace wall of the melting furnace so that its lower edge is flush with the hearth surface, as described above. The area of the opening in the lower end face of the pump cylinder is the same as the cross-sectional area of the perfectly circular hollow hole of the pump cylinder, and the shape of the opening is such that the dimension in the depth direction of the melting furnace is shorter than the width dimension, and The size of the horizontal nozzle part is sufficient to discharge the molten metal horizontally and is shorter than the thickness of the furnace wall, and the horizontal part of the nozzle and the pump cylinder are configured with an inclined part with the shortest distance, so the following effects can be achieved. be. In other words, after the cold material has been discharged from the molten metal by stirring work, when the stirring work of the cold material newly inserted into the furnace is restarted,
In the conventional method, the nozzle opening is perfectly circular, so
Previously, pump operation had to be suspended until the opening was filled with molten metal and air was not sucked in at the same time even if the molten metal was sucked into the pump cylinder.However, with the nozzle of the present invention, there is less risk of sucking in air; At the same time, since the molten metal is not oxidized by the sucked air, stirring can be started quickly, energy loss in the molten metal discharge flow is suppressed, and the jet from the nozzle can reach further distances in a horizontal direction. or collide with the cold material in the furnace to accelerate its melting.
As a result, the melting efficiency can be increased and the melting time can be shortened, resulting in significant fuel savings and yield improvement effects.

[Brief explanation of the drawing]

Figures 1 and 2 are drawings related to an embodiment of the present invention, where Figure 1A is a longitudinal sectional front view of the nozzle, and Figure B is Figure A.
20-20 sectional view of Figure C is arrow 21 of Figure A
-21 sectional view, FIG. 2A is a longitudinal sectional front view of the pump cylinder, FIG. B is a plan view of the pump cylinder, and FIG. 3 is a configuration diagram of a known mechanical stirring device. 1... Melting furnace, 2... Nozzle, 2a... Nozzle opening, 3... Intermediate, 4... Pump cylinder,
4a...Hollow hole section, 9...Vacuum blower, 10...
motor.

Claims (1)

[Scope of utility model registration request] In a molten metal agitation device that causes molten metal in a melting furnace to be sucked into a pump cylinder through a nozzle and then discharged, the opening area of the opening of the nozzle formed in the melting furnace is equal to the cross section of the opening in the lower end face of the pump cylinder. and the lower edge of the opening of the nozzle is on the same plane as the hearth surface, and the shape of the opening of the nozzle is selected so that the dimension in the depth direction of the melting furnace is shorter than the width dimension. , the nozzle is configured to have a horizontal nozzle portion that is sufficient to discharge the molten metal horizontally and is shorter than the thickness of the furnace wall, and an inclined nozzle portion that communicates with the pump cylinder. Nozzle structure of molten metal stirring device.