JPS6231363A - Immersion type electromagnetic pump - Google Patents

Abstract

PURPOSE:To maintain the pumping height constant by elevating an electromagnetic pump body in response to the elevation of a melted material surface level. CONSTITUTION:A winch 20 for winding/rewinding a lifter 21 is driven by an elevation motor 22 with a reduction gear, and an electromagnetic pump body 1 is mounted through a lifting arm 23 at one end 21a of the lifter 21. As a result, the body 1 is lifted elevationally movably by the winch 20, and the lower portion is immersed in melted material 2 in a holding furnace 24. Further, a melted material sensor 25 is mounted on the body 1, when the sensor contacts the material 2, a melted material detection signal S is supplied to a motor driving circuit 26 to stop rotating of the motor 22. Thus, when the melted material surface level 2a in the furnace 24 decreases, the signal S from the sensor 25 is not output, the circuit 26 rotates the motor 22 to drop the body 1. As a result, the pumping height H can be always maintained constant.

Description

[Detailed description of the invention] [Industrial application field] This invention is an immersion type 1 suitable for use when pumping m hot water!
Regarding magnetic pumps.

[Prior art]

As is well known, immersion type electromagnetic pumps are cylindrical induction! Magnetic pump, aluminum, zinc, tin.

Magnesium or alloys thereof are melted in a bath.
The lower part of the main body is immersed in water (temperature 300-800°C) and the molten metal is pumped up by electromagnetic induction.

It is discharged from the top of the main body.

This immersion electromagnetic pump is mainly used for tapping hot water into a continuous casting machine for producing ingots and the like.

[Problem that the invention seeks to solve]

By the way, when performing continuous casting, the amount of hot water discharged from the pump is required to be constant at all times in order to correspond to the mold number flowing at a constant cycle. However, in conventional immersion type electromagnetic pumps, the power is 1! There was a drawback that when hLfi went up or down, the pumping time increased by Km and the amount of hot water changed.

This invention was made in view of the above circumstances.

It is an object of the present invention to provide an immersion type electromagnetic pump that can always provide a constant amount of melt even if the molten metal surface rises and falls.

[Means for solving problems]

The above purpose? ! ? In order to achieve this, the present invention is characterized in that the pump body is raised and lowered according to the rise and fall of the molten metal surface, and that the pumping height is always constant.

In addition, the present invention provides an orifice in the hot water outlet in addition to the raising and lowering of the electromagnetic pump body, taking into account fluctuations in the amount of hot water dispensed per unit time due to fluctuations in the power supply voltage and fluctuations in coil impedance due to temperature rise, and a power supply circuit. The present invention is characterized by comprising at least one of the constant current control circuits to the constant current control circuit.

[For production]

By always keeping the pumping height constant, the amount of hot water produced is constant.

In addition, by providing an orifice, the amount of hot water can be reduced,
By alleviating fluctuations in the amount of pumping and providing a constant current control circuit, it compensates for fluctuations in current due to fluctuations in power supply voltage or changes in coil temperature.

〔Example〕

Embodiments of the present invention will be described below with reference to one drawing.

FIG. 1 is a front cross-sectional view showing the configuration of a submerged electromagnetic pump main body l according to a first embodiment of the present invention, in which the lower part of the electromagnetic pump main body 1 is immersed in bath water 2, and molten metal is pumped up by electromagnetic induction. 2 is designed to be discharged from the tap water gutter 3.

In this figure, a cylindrical body 4 is provided in the center of the electromagnetic pump body 1, and on the outside thereof, with a common axis, a circular pipe 52 made of refractory material and a metal protection covering the outer periphery of the circular pipe 5. A 6% hollow cylindrical casing 7 and a refractory material 8 covering the outer periphery of the casing 7 are disposed in this order. In addition, for example, six comb-shaped induction cores 9, 9... are arranged radially around the outer periphery of the protection tube 6, and annular coils 10° 10... are fitted around the outer periphery of the protection tube 6. It is fitted into the coil 10 from the outside.

To explain further, the induction core 9 is a columnar body having a planar sector shape, and a groove perpendicular to the axial direction is cut on the inner circumferential surface of the inductor core 9, and the coil 10 is fitted into the groove so that the inner circumferential surface becomes a protection pipe. It is still in contact with the outer peripheral surface of 6.

Next, between the cylindrical body 4 and the circular tube 5, fixing plates 11 made of refractory material are provided at 90° intervals to align the axes of the cylindrical body 4 and the circular tube 5. As a result, an annular bath water pumping passage 12 is formed between the cylindrical body 4 and the circular pipe 5,
When the coils 10 are excited with a predetermined phase difference, the molten metal 2 is pumped up through the passage 12.

Further, the one-round pipe 5 and the tap water gutter 3 are connected by an annular connector 13 having a U-shaped cross section.

Next, Figure 5g2 is a block diagram showing the overall configuration of the same immersion type electromagnetic pump. In this figure, 20 is a winch,
Reference numeral 21 denotes a hanging device such as a rope that is wound and unwound seven times by the winch 20. This winch 20 is driven by a lifting motor 22 with a reduction gear. On the other hand, a hanging arm 23 is fixed to the electromagnetic pump main body 1, and one end 21a of the hanging tool 21 is attached to this hanging arm 23.
is installed. Thereby, the electromagnetic pump main body 1 is suspended from the winch 20 so as to be able to rise and fall, and its lower part is immersed in the molten metal 2 in the holding furnace 24. In this case, the height at which the molten metal 2 is pumped is the height from the molten metal surface 2a to the inlet 3a of the tap trough 3.

Further, a molten metal sensor 25 is attached to the electromagnetic pump main body 1. This molten metal sensor 25 is a TA type level sensor, and when it comes into contact with the bath water 2.

The bath water detection signal S is supplied to the motor drive circuit 26.

When the molten metal detection signal S is not supplied from the bath water sensor 25, the motor drive circuit 26 rotates the lifting motor 23 to 1! While lowering the electromagnetic pump body 1, when a molten metal detection signal S is supplied from the molten metal sensor 25, the lifting motor 2
3 is stopped, and the height of the electromagnetic pump body 1 is maintained constant.

In the above configuration, the pumping height when the molten metal sensor 25 is in contact with the bath water surface 2a and the electromagnetic body 1 is held at a constant height is defined as H. In this state, the molten metal 2 is pumped out. When pumping is performed, #l'J)2 in the holding furnace 24 decreases, and the molten metal surface 2a gradually lowers. Eventually, when the molten metal surface 2a separates from the #molten metal sensor 25, the molten metal detection signal S is no longer output from the -m hot water sensor 25, and the motor drive circuit 26
to lower the electromagnetic pump body 1. Then, # when the hot water sensor 25 comes into contact with the molten metal surface 2a.

The #molten metal detection signal S is output from the molten metal sensor 25, and this
Accordingly, the motor drive circuit 26 stops the rotation of the lifting motor 22. As the electromagnetic pump body 1 descends as the molten metal level falls in this way, the pumping height is
H is always constant.

Next, FIGS. 3(A) and 3(B) are respectively the second
FIG. 1 is a cross-sectional view showing the configuration of a main part of a submerged disk '1 magnetic pump according to an embodiment, and its A-A, ill@ side view. This second
This embodiment differs from the first embodiment described above.

A top plate 30 is provided on the tap water gutter 3, and one force is applied to the tap water outlet 31 formed by the top plate 30 and the tap water tap 3.

The point is that a plate body 33 in which a rectangular notch 32 is formed is fitted. In this case, the cross-sectional area of the notch 32 is
As a result, an orifice 34 is formed by the notch 32.

With this configuration, even if the amount of hot water is reduced and the pumping pattern changes, fluctuations in the amount of hot water can be alleviated. As a result, even if the amount of hot water dispensed per unit time fluctuates when controlling the elevation of the electromagnetic pump, this fluctuation is alleviated.

Next, fluctuations in the amount of hot water dispensed by the magnetic pump also occur due to fluctuations in the pump coil current and tζ. Causes of variations in coil current include variations in power supply voltage and variations in coil impedance due to increases in temperature.

In order to prevent changes in the output 1ffi due to fluctuations in the coil current, the constant voltage shown in FIG. 4 is applied to the first and second embodiments described above. An It flow control circuit 40 is provided. In this Figure 4, 41 is the electromagnetic pump body, 42 is a power factor improving capacitor, and a constant -2 current control circuit #I40 is connected in series between the power supply W and the electromagnetic pump body 41. It is interposed.

The constant current control circuit 40 consists of two cyrisks 43 and 44 arranged in opposite directions and a controller 45.
Controller 45 is 1! Based on the flow signal F, a gate signal G is supplied to the thyristors 43 and 44, and the thyristor 43
．． 44 to keep the current supplied to the 'IIE magnetic pump body 41 constant.

〔Effect of the invention〕

As explained above, according to the present invention, the electromagnetic pump body is raised and lowered according to the rise and fall of the molten metal surface.
# Even if the surface changes, the pumping height can be kept constant, resulting in the effect that the amount of hot water always remains constant.

Additionally, in addition to raising and lowering the electromagnetic pump body, at least one of providing an orifice at the tap outlet and interposing a constant current control device in the power supply circuit can be added to prevent fluctuations in power supply voltage and temperature rises. It is possible to accurately compensate for fluctuations in the amount of hot water dispensed per unit time due to fluctuations in coil impedance.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing the configuration of a main body of a submerged electromagnetic pump according to a first embodiment of the present invention, and FIG. 2 is a block diagram showing the entire configuration of the submerged electromagnetic pump. FIG. 3 is a sectional view showing the configuration of the main parts of an immersion type electromagnetic pump according to a second embodiment of the present invention, and FIG. 4 is a block diagram showing the configuration of a constant current control circuit for keeping the coil current constant. be. 1...'ti pump body (main body), 2...
...# Hot water, 2a... Molten metal surface, 3... Output gutter (output; cell), 22... Lifting motor with speed reducer (lifting means), 25. ... Level sensor (detection means), 34 ... Orifice, 40 ...
- Foot current control circuit.

Claims (5)

[Claims] (1) An immersion type electromagnetic pump that pumps up molten metal by electromagnetic induction by energizing a coil and discharges the molten metal from an outlet at the top of the main body, which is equipped with a means to keep the amount of molten metal constant as the level of the molten metal decreases. An immersion type electromagnetic pump featuring: (2) A patent claim characterized in that the means for making the amount of tapped metal constant comprises a detecting means for detecting the molten metal surface and an elevating means for elevating the main body based on the detection result of the detecting means. The immersion type electromagnetic pump according to item 1. (3) The means for keeping the amount of tapped metal constant includes a detection means for detecting the molten metal surface, a lifting means for raising and lowering the main body based on the detection result of the detection means, and an orifice provided in the tapping section. An immersion type electromagnetic pump according to claim 1, characterized in that the pump comprises: (4) The means for making the amount of hot water constant include a detection means for detecting the surface of the molten metal, a lifting means for raising and lowering the main body based on the detection result of the detection means, and a means for keeping the current flowing through the coil constant. 2. The immersion type electromagnetic pump according to claim 1, comprising a constant current control circuit. (5) The means for keeping the amount of tapped metal constant includes a detection means for detecting the molten metal surface, a lifting means for raising and lowering the main body based on the detection result of the detection means, and an orifice provided in the tapping section. 2. The immersion type electromagnetic pump according to claim 1, further comprising: and a constant current control circuit that keeps the current flowing through the coil constant.