JPS58185730A - Control device for stirrer for molten metal - Google Patents

Abstract

PURPOSE:To provide a titled device which permits easy maintenance by the constitution wherein the top end part of a riser pipe connected to a melting surface is connected to a vacuum source and the waste gas source of the melting furnace through a selector valve which is operated by a gas, under the surface of molten metal. CONSTITUTION:The top end part 11 of a riser pipe 10 connected to a melting furnace 1 under the surface 8 of the molten metal 5 in a melting furnace 1 provided to a 3-way selector valve 18 communicating with a vacuum source 20 and a duct 24 for conduction of the waste gas of the furnace 1 through a protection tank 13 and a filter 16. To stir the molten metal 5, the penumatic cylinder (not shown) of the valve 18 is operated by a control device 40 to connect a valve chamber to the soruce 20 so that the metal 5 is sucked up into the evacuated pipe 10. The pneumatic cylinder is then operated to connect the valve chamber to the gas source to feed the waste gas from the duct 24 into the pipe 10 through a pipeline 21 so that the metal 5 sucked therein dropped by gravity and is returned into the furnace 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to the melting furnace. g #11 Metal surface Metal surface A stirring device for molten metal connected to the metal surface melting furnace, in which the upper end of the riser tube is connected to a vacuum source or a gas source via a switching valve. This invention relates to a control device for

In the prior art, a solenoid valve such as the above-mentioned switching valve V'i is used, which solenoid valve is controlled by an electric circuit. Such solenoid valves have a relatively short life span and have therefore resulted in interruptions in continuous operation for melting metals.

An object of the present invention is to provide a control device for a molten metal stirring device that is easy to maintain.

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a horizontal sectional view thereof. fg111!1lFilvC
Burner 2 is installed. By means of this fi, the ingots or scraps input from the input preheating chamber 3.4 are vc-melted as indicated by reference numeral 5. This molten metal 5 is, for example, aluminum. Molten metal 5 is taken out to the outside through a take-out port 6.7.

Molten metal 50 in the melting furnace 1 Table 1 From IO8, a riser pipe 10 is installed near the corner of the melting furnace 1. This rise 'tlOH1fg extends vertically outside the melting furnace 1. An inspection window 62 is provided at the upper end 11 of the riser pipe IO. This upper end portion 11 is connected to a protection tank 13Vc via a conduit 12. Protective tank 13 is connected to filter 16 via duct 14 and valve 15 . It is connected to a three-way switching valve 18 via a filter 16μ and a conduit 17.

The three-way switching valve 18 connects the conduit 17 to one via the conduit 19.
Connect to empty #20 or connect pipe 17 to metal pipe 21. The charging preheating chambers 3, 4vc are connected to ducts 22, 23 that guide exhaust gas from the melting furnace 1. Stack 25 through duct 22, 2:lj, duct 24'c
VC leads, causes dissipates, n, ru.

'i electric line 21 is connected to duct 24VC. The protective tank 13 prevents a portion of the molten metal 5 sucked into the riser 10 from flowing in through the line 11 and 12 and erroneously flowing into the line 14 and beyond, thereby protecting all subsequent equipment.

FIG. 3 is an enlarged sectional view of the riser 10.

The radially inner side of the riser pipe 10 is made up of a heat insulating material 28, and the outside of this heat insulating material 28 is covered with a heat insulating material 29. The heat insulating material 29V'i is covered with an outer cover 30 made of iron or the like. At the upper end of the riser pipe 10, surrounded by a heat insulating material 28, a 4-air heater 31 is provided. This electric heater 31 is energized by electric power and heats the portion of the heat insulating material 28 surrounded by the electric heater 31 to, for example, 650 to 7506C. This rLK prevents the molten metal sucked into the riser 10 from solidifying near the surface 32 where it reaches. Therefore, blockage in the riser IO is prevented.

When the pipes 17 and 19 are connected through the three-way switching valve 18, the pressure in the pipe 12 is low, and the molten gold in the melting furnace l is sucked into the riser pipe 10.

Ru. The surface of the sucked molten metal 5 in the riser 10 has a rough surface 32 as clearly shown in Figure @3.
It's nearby. After that, the three-way switching valve 18 is switched once, and the pipe W! 117 is connected to the conduit 21. Exhaust gas is guided from the ninth duct 24 to the -C1 pipe 12 via the pipe 21. This exhaust gas collects in the riser 10 as the molten metal in the riser 10 returns directly to the melting furnace 1.

In this way, to take advantage of the fact that molten metal falls on chalk,
Configuration becomes easier. As the molten metal in the riser tube 10 returns to the melting furnace 1, the molten metal in the melting furnace 1 rotates in the direction indicated by the arrow 33 in FIG. 2 and is stirred. . Although the riser pipe lO is provided near the corner of the melting furnace l, it may be provided at the level of the pond Ill.

The oxygen concentration If of the exhaust gas is low, so that oxidation of the molten metal 5 sucked into the riser pipe 10 is suppressed.

This also suppresses blockage due to oxides in the vertical pipe IO.

FIG. 4 is a sectional view showing a specific configuration of the three-way switching valve 18. A valve body 35 is housed in the valve box 34 .

A valve rod 36 fixed to the valve body 35 is driven to reciprocate in its axial direction (7F direction in FIG. 4) by a pneumatic cylinder 37. Sky・λ! When the ring 37 is extended and the valve body 35 is in the state shown in the fourth figure, the pipe! 17 communicates with the pipe line 19vc via the valve chamber 60. The pneumatic cylinder 37 is contracted, so that the valve body 35 is aligned with the imaginary line 38.
When the koji is maintained at the position shown in , the pipe line 17 is communicated with the pipe line 21 via the valve chamber 60. This Mikata IJJ
Of course, it may be realized by the changeover valve 18Vi and the four functions.

Figure @5 shows the pneumatic circuit of the control device 40 for controlling the pneumatic cylinder 37 that drives the three-way switching valve 18. To the air pressure from the air pressure source 41 and from the pipe line 42 to the operation valve 4
3.44. The operation valve 43 is connected to the operation valve 45 ζ1. Ru. The operating valve 44 is connected to the operating valve 46 . The timer circuit 47VC is applied to the air pressure from the operation valve 45.
,ru. The air pressure from the tie size circuit 47 and the operating valve 46 is given as pilot pressure to the spring offset pear pilot type two-position switching valve 49 from the OR circuit 48 and the pilot line 52. Air pressure from the air pressure source 41 is applied via a switching valve 49 from a conduit 61 to one chamber 50 of the pneumatic cylinder 37 and then to the other chamber 51 .

In order to dynamically stir the molten metal 5 in the melting furnace 1, the operation valves 43 and 45 are connected to the communication state f! Operated by A. Kof
Therefore, as shown in FIG. 8, the timer circuit 47 releases the air pressure supply to the pilot line 52 by rfflW1 at the first time, and supplies Vc air pressure to the pilot line 52 only by opening W2 at the next time. In this way, the pressure in the chamber 50 of the air cylinder 37 becomes high for the time Wl, and the pipe line 1
7 and 19 communicate with each other, and the molten metal 5 is sucked into the n1 riser pipe 10. Also, at the next time W2, the pneumatic cylinder 370
The pipes 17 and 21 are connected to each other, and exhaust gas is supplied to the riser pipe 10. For example, time W
1=4 to IO seconds, W2-2 to 4 seconds.

The on-delay circuit 53 (1) included in the timer circuit 47 performs the 41 operation shown in FIG. 6. When the air pressure shown in FIG. The off-delay circuit 54 communicates with the pilot boat 54a after the time Tl as shown in FIG. 6(2).
Boat 5 when the air pressure shown in figure ill is given.
4b and 54c as shown in Fig. 7 (2).
Shut off after T2 has elapsed.

1. When manually switching the IJ alarm valve 49, the operation valve 44 is kept in communication, and the operation valve 46 is shut off. Air pressure is not supplied to the pilot line 52,
The stand tube 10 is therefore connected to a vacuum source 20. Further, if the operating valve 44 is kept in communication with the operating valve 461, air pressure is applied to the pilot pipe W152, and exhaust gas can be supplied to the riser pipe 10.

As described above, since the switching valve is switched by gas pressure, there is no need to open and close electrical contacts as described in the prior art, which makes maintenance easier. Become.

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of one embodiment of the end 1, Figure vJ2 is its cross-sectional view, Figure @3 is an enlarged cross-sectional view of the riser 10, and Figure 4
The figure is a sectional view of the three-way switching valve 18, and the control device 40 is shown in FIG.
6 is a waveform diagram showing the operation status of the on-delay circuit 5301, FIG. 7 is a waveform diagram showing the operating status of the off-delay circuit 54, and FIG. 8 is a waveform diagram of the timer circuit 47.
FIG. DESCRIPTION OF SYMBOLS 1... Melting furnace, 5... Melting metal ring, lO... Standing pipe, 18... Three-way switching square, 2o... Vacuum source, 31...
...Electric heater, 37...Pneumatic cylinder, 40...
・Control device agent Patent attorney Kei Nishi

Claims (1)

[Scope of Claims] (g) A melting device connected to the melting furnace below the surface of the molten metal and having the upper end of the primary riser connected to the vacuum source or gas dA via a switching valve. gold stirring bag i
#t A control device for a molten metal stirring device, characterized in that the switching valve ri is switched by gas pressure.