JPS5943824Y2 - Annular flow path type linear induction electromagnetic pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic pump, and more particularly to an annular channel type linear induction pump.

Generally, as shown in Fig. 1, this type of electromagnetic pump includes a cylindrical duct 1 that forms a flow path for a conductive fluid such as liquid sodium, and is attached to the outer periphery of the cylindrical duct 1 via a heat insulating material 2. The stator 3 includes a plurality of comb-shaped laminated cores 4 arranged radially, an induction coil 6 fitted into each slot 5 of the core 4, and a cylindrical duct l.
-1, it is composed of the duct 1 and an iron core 8 housed coaxially with a spacer 7 interposed therebetween.

When transferring a conductive fluid, the stator 3 of the KU is excited with a multiphase alternating current to generate a moving magnetic field in the axial direction of the cylindrical duct 1, and this moving magnetic field cuts the conductive fluid. An induced current is generated, and the interaction between this current and the moving magnetic field causes an electromagnetic force to act on the conductive fluid in the same direction as the moving magnetic field, thereby causing the conductive fluid to be transported in the direction of arrow A in the drawing.

Generally, in this type of electromagnetic pump for molten metal, the cylindrical duct must be preheated to a temperature higher than the melting point of the liquid metal to be transferred.

For example, when the liquid metal to be transferred is liquid sodium, it needs to be preheated to about 200 to 300°C, and as a preheating means, the following induction heating method has conventionally been adopted.

That is, before introducing liquid metal into the cylindrical duct 1, the stator 3 is excited with a multiphase alternating current to induce a current in the cylindrical duct 1 made of non-magnetic metal, and the Joule heat generated by this current is utilized. to preheat it.

When the cylindrical duct 1 is heated in this way and reaches the set temperature, the power is turned off and the excitation of the stator 3 is stopped.
The liquid metal is introduced into the cylindrical duct 1, and when it is introduced during preheating, a driving force (
This is because electromagnetic force) is generated.

However, when such a preheating means and a structure using a heat insulating material as shown in FIG. 1 are adopted, the following two drawbacks occur.

A heat insulating material 2 is provided around the outer periphery of the cylindrical duct 1 to prevent damage to the induction coil 6 due to heat. However, when the cylindrical duct 1 is heated, a Since a difference in thermal expansion occurs, which causes a large thermal stress between the stator 3 and the cylindrical duct 1, it is necessary to configure the heat insulating material 2 to be slidable with respect to the cylindrical duct 1.

However, if the stator 3, the heat insulating material 2, and the cylindrical duct 1 are not in close contact with each other, undesirable vibrations will occur in the stator 3. This is the first drawback, as it becomes very difficult to select.

Another drawback arises when the liquid metal is introduced into the cylindrical duct 1; as already mentioned, the liquid metal is introduced after the cylindrical duct 1 has been preheated; Differences in expansion occur between members due to temperature differences.

Moreover, since this is instantaneous, thermal shock stress is generated, which causes considerable fatigue in the cylindrical duct.

The object of the present invention is to provide an annular flow path type linear induction electromagnetic pump that can eliminate the above drawbacks.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 2 shows an electromagnetic pump according to the present invention.
0(/'i Nutator mounting tube, on the outer peripheral surface of which is attached the stator 3, which is composed of the aforementioned comb-shaped laminated core 4 and the induction coil 6 fitted into the slot portion 5 of the core 4. There is.

A cylindrical duct 1 is coaxially inserted into the inner axial direction of the stator mounting pipe 10 via a ring-shaped spacer 12 that is slidable on the inner peripheral surface of the stator mounting pipe 10 .

The distance between the inner circumferential surface of the stator mounting pipe 10 and the outer circumferential surface of the cylindrical duct 1 can be adjusted appropriately by changing the thickness of the ring-shaped spacer 12. Therefore, when the cylindrical duct 1 is heated, From duct 1 to stator mounting pipe 10
The degree of heat transfer to can be adjusted by adjusting the thickness of the spacer 12.
By maintaining an appropriate distance between the cylindrical duct 1 and the stator mounting pipe 10, a heat insulating effect can be provided, so that the gap 14 (
I″i constitutes a heat insulating means.

As shown in the third figure, the ring-shaped spacer 12 is cut in the radial direction, and both ends thereof have a desired distance B in the circumferential direction, and a groove 16 is formed on the outer circumferential surface.

The groove 16 is provided to prevent heat transfer from the cylindrical duct 1 to the stator mounting tube 10 via the spacer 12, and the contact area between the outer peripheral surface of the groove 16 and the inner peripheral surface of the stator mounting tube 10 is minimized. In order to reduce the size, it is preferable that the number of grooves 16 is large.

A flexible material is selected as the material for the ring-shaped spacer 12.

Therefore, when a micro-heater 18 (described later) is wound around the cylindrical duct 1, the micro-heater 18 can cross the gap B formed between both ends of the spacer 12 as shown in FIG. The winding of the spacer 18 can be done by twisting the spacer 12 in the axial direction of the cylindrical duct 1 depending on the angle.

The cylindrical duct 1 is heated for preheating, and a strip micro-heater 18 is used as the heating means.

This micro heater 18 is wound around the cylindrical duct 1 in the longitudinal direction, and has terminals 18 a t 18 at both ends.
b, and the wound microheater 18 is fixed by a band 20 at the end of the cylindrical duct 1 protruding from the stator attachment pipe 10.

In FIG. 4, an electromagnetic pump having such a configuration is shown in the pump chassis 2.
2 is shown installed.

One end of the cylindrical duct 1 protruding from the stator mounting pipe 10 is fixed to the support base 26 of the chassis 22, and the other end is attached with a U-shaped bolt 28 so as to be slidable in the axial direction of the cylindrical duct 1 and perpendicular thereto. Movement in this direction is now restricted.

30(/'i, stator band for fixing the stator 3 to the chassis 22, 32(/'i stator band 3)
It is a fixing diagram for fixing 0.

The operation will be explained below based on the above configuration.

First, when the terminals 18a and 1sb of the micro heater 18 are connected to the power source and the cylindrical duct 1 is preheated, the cylindrical duct 1
temperature rises, the cylindrical duct 1 expands accordingly, and the spacer 12 slides on the inner circumferential surface of the stator mounting tube 10.

When the stator 3 is excited with a multiphase alternating current when the cylindrical duct 1 reaches the set temperature, a moving magnetic field is generated in the axial direction of the cylindrical duct 1.

When a conductive fluid is introduced into the cylindrical duct 1 in this state, the moving magnetic field cuts the fluid, so an electromagnetic force acts on the fluid and the fluid is transported.

As explained above, the present invention includes a cylindrical duct for forming a flow path for a conductive fluid, a stator installed outside the cylindrical duct to generate a moving magnetic field in the axial direction of the cylindrical duct, and a stator for generating a magnetic field moving in the axial direction of the cylindrical duct. In an annular flow path type linear induction electromagnetic pump equipped with an iron core provided inside a cylindrical duct, the stator is attached to the outer periphery and the stator mounting pipe for arranging the cylindrical duct inside is cylindrical. The ring-shaped spacer to be interposed between the cylindrical duct and the stator mounting pipe is made of a flexible member that is cut in the radial direction and has a groove on its outer circumferential surface, and a heater for heating is installed on the outer circumference. The cylindrical duct wrapped around the cylindrical duct is inserted into the stator mounting pipe, and there is a space between the inner peripheral surface of the cylindrical duct and the outer peripheral surface of the stator mounting pipe so that the cylindrical duct and the stator mounting pipe can move freely relative to each other. The ring-shaped spacer is interposed therein, and a heat-insulating gap is interposed between the inner circumferential surface of the cylindrical duct and the outer circumferential surface of the stator attachment tube.

Therefore, in the case of the present invention, the cylindrical duct and the stator are movable with respect to each other, and the expansion of the cylindrical duct during preheating is independent of the stator, so the stator is not affected by the expansion of the cylindrical duct. Not only does no thermal stress occur between the cylindrical ducts, but even if a conductive fluid is introduced into the cylindrical ducts after preheating, the expansion of the cylindrical ducts has no effect on the stator, so thermal shock stress does not occur between the stators. This prevents fatigue of the cylindrical ducts.

Moreover, in the case of the present invention, the following effects can also be obtained.

First, a ring-shaped spacer is interposed between the cylindrical duct and the stator mounting pipe, but since the spacer is ring-shaped, it can be moved between the inside and outside of the two without special support means. It can be stably interposed between the peripheral surfaces.

In addition, as a ring separation effect, the spacer expands in diameter,
By being able to reduce the diameter, it is possible to accommodate various sizes of cylindrical ducts and stator mounting pipes, and the outer circumference of the cylindrical duct is
Do not obstruct the wrapping of the attached heater;
The spacer itself absorbs expansion and contraction due to heat at the separation interval, so it has greater stability as a spacer, and its open-loop configuration makes it easy to attach the spacer. The effect of a certain groove is that the contact area becomes smaller, which increases the heat transfer prevention effect to the stator mounting tube, that the insulation gap becomes larger by the groove, and that the thickness of the spacer is reduced by the groove. It has increased flexibility and fits well into cylindrical ducts, etc.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view showing a conventional electromagnetic pump, FIG. 2 is a partially cutaway perspective view of an electromagnetic pump according to the present invention, and FIG.
The figure is a plan view of the ring-shaped spacer used in the same pump.
FIG. 4 is a perspective view showing how the pump is installed on the pump chassis. 1...Cylindrical duct, 3...Stator,
8...Iron core, 10...Stator mounting pipe, 12...Ring-shaped spacer, 14...
・Gap for insulation, 16... Spacer groove, 18
−・−・Micro heater.

Claims (1)

[Scope of utility model registration request] a cylindrical duct for forming a flow path for a conductive fluid; a stator installed outside the cylindrical duct for generating a magnetic field moving in the axial direction of the cylindrical duct; and a stator provided inside the cylindrical duct. In the annular flow path type linear induction electromagnetic pump equipped with an iron core, the stator mounting pipe for mounting the stator on the outer periphery and housing the cylindrical duct inside is cylindrical, and the cylindrical duct and the stator mounting pipe are cylindrical. The ring-shaped spacer to be interposed between the pipe and the cylindrical duct is cut in the radial direction and is made of a flexible member having a groove on its outer circumferential surface, and a heater for heating is wound around the outer circumference of the cylindrical duct. is inserted into the stator mounting pipe,
At the same time, the ring-shaped spacer is interposed between the inner circumferential surface of the cylindrical duct and the outer circumferential surface of the stator attachment tube so that the cylindrical duct and the stator attachment tube can move freely relative to each other, and the inner circumferential surface of the cylindrical duct An annular flow path type linear induction electromagnetic pump in which a heat insulating gap is interposed between the outer circumferential surface of the stator mounting tube and the outer circumferential surface of the stator mounting tube.