JP2933665B2 - Stirrer and stirrer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stirrer that stirs a sample by using a magnetic attraction force and a stirrer using the stirrer.

[Conventional technology]

When concentrating a sample such as a synthetic solution or removing volatile substances in the sample, it is necessary to stir the sample while heating it under reduced pressure. In such agitation, it is necessary to provide a container for accommodating the sample with airtightness capable of performing good pressure reduction and heating. Separated from the driving machine,
There has been proposed an apparatus in which a sample in a container is agitated in a non-contact state by using an attractive force of a magnet provided in a driving device.

This type of stirrer has two main structures, one of which rotates a separation tube containing a sample and stirs it by centrifugal force, as shown in FIG. As shown in FIG. 5, a rotating stirrer is provided in a container storing a sample so as to directly stir the sample.

The stirrer shown in FIG. 4 forms a stirrer C by arranging a magnet plate 54 connected to a motor 52 inside a case 51 such that an upper surface 54a thereof is close to a top plate 55 of the case. The turntable 56 for supporting the separation tube 60 is housed in a decompression vessel 57 provided at the upper part of the machine C.

The turntable 56 is rotatably supported on a support shaft 58 provided on the same axis as the motor shaft 53 on the top plate 55, and an operation disk 59 is attached to a lower portion of the turntable 56. The lower surface 59a of the working disk 59 is close to the top plate 55 with the turntable 56 attached to the support shaft 58. A magnet plate is used for the working disk 59, and an opposite magnetic pole is formed on a lower surface 59a thereof in correspondence with the magnetic pole of the magnet plate 54.

On the other hand, in the structure shown in FIG. 5, a support shaft 63 is rotatably provided in a container 61 for storing a sample via bearings 62, 62, and an operating disk 64 and a stirring blade 65 are mounted on the support shaft 63. Consists of
The working disk 64 is formed of a magnet plate. When using,
The above-mentioned container 61 is stirred by a stirring drive C
And put it on.

In the above two structures, when the magnet plate 54 is rotated by the motor 52, the turntable 56 or the stirring blade 65 is rotated by the attractive force between the magnetic plate 54 and the magnetic pole of the working disk 59 or 64, and the separation tube 60 is rotated. Alternatively, a rotational force is applied to the sample inside the container 61 to stir the sample.

[Problems to be solved by the invention]

By the way, as described above, the operating disk is
In the method of rotating 59 and 64, the direction in which the magnetic poles of the magnet plate 54 and the magnetic poles of the working disks 59 and 64 face each other becomes a problem. That is, in order to obtain an attractive force, the facing magnetic poles need to have opposite polarities, but the turntable 56 or the stirring blade 65
If the magnetic poles of the working disks 59, 64 and the magnet plate 54 become the same during rotation of the rotating disk 5, the repulsive force between the magnetic poles causes the working disk 5
There is a problem that 9, 64 rotates in the opposite direction and causes vibration.

Further, in the stirring device, a function of changing the rotation speed of the turntable 56 or the stirring blade 65 is required to change the rotation force applied to the sample, but the rotation speed of the magnet plate 54 is rapidly increased in order to change the rotation speed. When it is changed to, the attraction force by the magnet cannot follow the change in the inertial force caused by the speed change, and the operation disk 59,
The rotation of 64 may be delayed. When the rotation delay occurs in this way, a repulsive force is generated between the magnets between the magnet plate 54 and the working disks 59 and 64, and the rotation of the working disks 59 and 64 becomes uneven.

Further, in the case of the structure of FIG. 5, the faster the stirring blade 65 rotates in the sample, the greater the fluid resistance becomes, and the larger the force for stopping the movement of the stirring blade 65 becomes. Since such resistance acts to delay the rotation of the stirring blade 65 more than the rotation of the magnet plate 54, it is necessary to keep the rotation of the blade 65 low so as not to be delayed from the rotation of the magnet plate 54 due to the resistance force of the fluid. There is a problem that the rotation limit restricts the stirring ability. In fact, with the conventional structure using stirring blades, the capacity is
There is a drawback that stirring of a sample up to 20 to 30 liters is a limit, and improvement in working efficiency by stirring with a large volume cannot be expected.

In the structure in which the stirring blade is rotated inside the sample, it is necessary to strictly prevent the sample from being contaminated with metal powder or the like.However, in the case of the conventional structure in which the working disk 64 is formed of a magnet plate, Therefore, the centrifugal force applied to the support shaft 63 is increased, and there is a disadvantage that metal powder due to rubbing friction is easily generated from a contact portion between the support shaft 63 and the bearings 62, 62.

[Object of the invention]

The present invention has been made in view of the above problems,
It is an object of the present invention to provide a stirrer which is not affected by a repulsive force generated between magnets and can rotate smoothly following the rotation of a magnet plate, and a stirrer using the stirrer.

[Means for solving the problem]

In order to solve the above-mentioned problems, the stirrer of the present invention provides a fitting hole for a bearing at the center of a plate made of a non-magnetic conductive material, and a support for a separation tube for accommodating a sample is provided above the plate. The structure was connected.

Further, the stirrer of the present invention rotatably supports the stirrer via a bearing on a shaft protruding from the upper surface of the bottom plate of the container. A magnet plate connected to the motor shaft is arranged so as to be located within a range where magnetic induction is possible, and the rotation center of the magnet plate and the agitator is located on the same axis, and the magnet plate is opposite to the upper surface of the magnet plate. Are formed.

[Action]

In the stirring device having the above structure, when the magnet plate rotates,
The magnetic flux generated in the upper part of the magnet plate rotates at the same time, the magnetic flux crosses the plate material, and an induced current is generated in the plate material by the electromagnetic induction action.

This induced current reacts with the magnetic flux to generate a moving force in the plate material in proportion to the strength of the magnetic flux. In this case, since the plate is rotatably supported coaxially with the center of rotation of the magnet plate, the moving force acts as a rotational driving force on the plate.

In the above structure, the plate material is made of a non-magnetic material, and by using a highly conductive conductor having a small electric resistance, a magnetic attraction force is not generated between the plate and the magnet plate, and the induced current due to electromagnetic induction can be improved. As a result, a large driving torque can be obtained.

The driving torque thus obtained is generated by the interaction between the induced current and the magnetic flux, so there is no repulsion between the same magnetic poles, and the magnitude of the driving torque depends on the strength of the magnetic flux and the speed at which the plate material cuts off the magnetic flux. , The plate material rotates accurately following the rotation of the magnet plate.

〔Example〕

1 and 2 show a first embodiment of the present invention.

This stirrer includes a stirrer A and a decompression container 7 mounted thereon.

The motor 1 is mounted on the inner bottom surface of the case 1 of the stirring drive A, and a disk-shaped magnet plate 4 whose center axis coincides with the center of the shaft 3 is attached to the tip of the shaft 3 of the motor 2. Have been.

The magnet plate 4 is mounted such that opposite poles (N-pole and S-pole) are magnetized on the upper surface 4a, and the upper surface 4a is opposed to the lower surface of the top plate 5 of the case 1 in parallel.

An alumite-processed aluminum plate or bakelite plate is used for the top plate 5 of the case 1.

The decompression container 7 includes an inner container 11 and an outer container 12. The inner container 11 is provided with an air suction pipe 13 that penetrates the outer container 12 and protrudes to the outside. A pipe 14 connected to a pump (not shown) is connected, and the inside of the inner container 11 can be depressurized by sucking air from a suction pipe 13 thereof.

Further, a sealed pipe heater 15 is attached to the outer peripheral wall of the inner container 11, and a heat insulating material 16 is provided between the pipe heater 15 and the outer container 12, so that the temperature of the inner container decreases when the pressure is reduced. Heating of the gas in 11 and heating for the separation operation are performed by heating the pipe heater 15. The pipe heater 15 is provided with a temperature sensor 17, and a heating temperature is adjusted by operating an adjustment knob 18 attached to the outer container 12.

A support shaft 8 is mounted on the upper surface of the bottom plate 19 of the decompression container 7 so as to coincide with the axis of the motor shaft 3, and the agitator 21 can be rotated on the support shaft 8 via bearings 20, 20. Mounted on

The stirrer 21 is configured such that the turntable 6 of the separation tube 10 is attached to the upper end of the cylindrical member 22 and the operating disk 9 is attached to the lower end. The turntable 6 is provided with an inclined plate 23 inclined outward and upward concentrically with respect to the axis of the support shaft 8, and an insertion hole for radially inserting the separation tube 10 along the peripheral surface of the inclined plate 23.
24 is formed.

The working disk 9 is formed in a disk shape in which the axis of the support shaft 8 and the central axis coincide with each other, and the lower surface 9a is formed on the upper surface 4a of the magnet plate 4.
And is attached to the bottom plate 19 with a slight gap. The gap t between the lower surface 9a of the working disk 9 and the upper surface 4a of the magnet plate 4 is set within a range where the magnetic flux of the magnet plate 4 can cause an electromagnetic induction action.

The working disk 9 is made of a non-magnetic material and a conductor having good conductivity. For example, an aluminum plate or a copper plate can be used.

This embodiment has the above-described structure, and its operation will be described below.

On the upper part of the magnet plate 4, magnetic poles (N
It is considered that the magnetic flux F straddling the upper surface 4a is generated by the pole and the south pole as shown in FIG.

Now, when the motor 2 is operated to rotate the magnet plate 4, the stopped working disk 9 crosses the magnetic flux F,
For this reason, an induced current is generated in the working disk 9 by electromagnetic induction. The induced current reacts with the magnetic flux F to generate a driving torque in a direction to cancel a motion of generating an induced current in the working disk 9, that is, in the same direction as the rotating direction of the magnet plate 4.

Therefore, the working disk 9 rotates with the same rotation as the magnet plate 4 (because the working disk 9 needs to cut off the magnetic flux F, the working disk 9 is slightly delayed in the rotation direction from the magnet plate 4). Then, centrifugal force is applied to the sample liquid in the separation tube 10 attached to the turntable 6.

In the above case, no magnetic attraction force acts between the working disk 9 and the magnet plate 4, and the driving torque is generated by the interaction between the induced current and the magnet, so that no repulsive force acts between the magnetic poles. There is no problem that the working disk 9 rises during rotation and uneven rotation occurs.

Further, since the magnitude of the driving torque changes in proportion to the speed at which the working disk 9 cuts off the magnetic flux F, when the rotational speed of the magnet plate 4 is rapidly changed, the driving torque is also changed according to the amount of change. Therefore, the working disk 9 becomes the magnet plate 4
The rotation speed changes exactly following the rotation of.

〔The invention's effect〕

As described above, the present invention does not generate a magnetic attraction force between the magnet plate and the stirrer, but generates an induction current in the stirrer that supports the separation tube on the support table by electromagnetic induction. Since the drive torque is obtained by this, it is possible to prevent the stirrer from floating and uneven rotation due to the repulsion of the magnet, and to accurately follow the rotation of the magnet plate with the rotation of the magnet plate.

In addition, since there is no need to synchronize the rotation of the stirrer and the magnet plate, the rotation of the stirrer can be greatly accelerated, and the stirring ability can be greatly increased.

Therefore, by using the stirring device of the present invention, a smooth and large stirring force can be added to a highly airtight decompression container, and there is an effect that a highly efficient separation operation can be realized.

[Brief description of the drawings]

FIG. 1 is a partially longitudinal front view showing a first embodiment according to the present invention, FIG. 2 is a longitudinal front view showing essential parts of the above, FIG. 3 is a view showing the operation of the above, and FIG. FIG. 5 is a vertical sectional front view showing another conventional structure. 1 ... case, 2, 32 ... motor, 3 ... motor shaft,
4, 34: magnet plate, 6: turntable, 7: decompression container, 8: support shaft, 9: working disk, 10: separation tube, 21
…… a stirrer,

Claims (2)

(57) [Claims] A stirrer in which a fitting hole for a bearing is provided at the center of a plate made of a non-magnetic conductive material, and a support for a separation tube for accommodating a sample is connected above the plate. 2. The stirrer according to claim 1, wherein the stirrer is rotatably supported via a bearing on a shaft protruding from an upper surface of a bottom plate of the container.
Below the bottom plate of the container, a magnet plate connected to the motor shaft is arranged such that the upper surface is located within a range in which the magnetic plate can be magnetically guided with respect to the plate material of the stirrer. A stirrer which is located on the same axis and has opposite magnetic poles formed on the upper surface of the magnet plate.