JPH0368466A - Vibration restraining device for centrifugal separator - Google Patents

Abstract

PURPOSE:To prevent the generation of self-exciting vibration by providing dampers to the upper and lower surfaces of the nonrevolving disk provided in a bearing fixing part so that the disk is located between both dampers and has gaps to each damper. CONSTITUTION:The upper damper 24 is provided on the inner surface of the upper member 7 of the housing 4 surrounding the driving part 2 provided on a slab 1, and the lower damper 25 is provided on the flange 10b of a spherical pedestal 10 fixed on the flange 5a in the lower member 5. These upper and lower dampers 24, 25 are so located that the nonrevolving disk 12a of a bearing cylinder 12 is inserted between the dampers with the gaps to each damper. When the gap l2 between the top end of the nonrevolving disk 12a and the upper and lower dampers 24, 25 is set due to the value calculated by the specified equation, the top end of the nonrevolving disk 12a is brought earlier into contact with the upper and lower dampers 24, 25 than a revolving shaft 9 so that the vibration is restrained without generating unstable vibration as the revolving shaft 9 is not brought into contact, and a stable revolving state is early obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to a vibration damping device for a centrifuge having a suspended rotating bowl for performing solid-liquid separation.

(Prior art) When reprocessing nuclear fuel, etc., a centrifugal clarifier separates and removes solid fine particles of insoluble nuclear fission products from a nitric acid solution in which spent nuclear fuel is dissolved, and uranium or plutonium and fission products in the solution after clarification are used. A centrifugal extractor is used to perform liquid-liquid extraction to separate the

The centrifugal separators used in such equipment handle highly radioactive materials.

Therefore, a rotating container hanging structure is adopted in which the rotating bowl, drive unit, and bearing that come into contact with the processing liquid can be isolated by a radiation shielding slab.

An example of these is disclosed in Japanese Unexamined Patent Publication No. 124553/1983.

That is, as illustrated for the centrifugal separator in FIG. 4, the drive 112 is provided above the radiation shielding slab 1, and the wetted part 3 is provided below, and the two are isolated by the radiation shielding slab 1. ing.

The housing 4 of the drive unit 2 has an inner flange 5a, and is formed by a lower member 5 whose lower surface is fixed to the upper surface of the slab 1, and an upper member 7 which is fixed to the upper surface and has a motor 6 on its upper surface. .

A drive shaft 9, which protrudes from the motor 6 through the slab 1 and below the slab 1, and has a rotary bowl 8 suspended from its lower end, is supported so as to be swingable and rotatable in the following manner. That is, an upwardly opening spherical seat 10 is attached to the upper surface of the inner flange 5a, and a ball bearing 1 engaged with the drive shaft 9 is mounted on the upper surface of the inner flange 5a.
The bearing tube 12 supporting the concave spherical surface 10 of the spherical seat 10
It has a convex spherical surface 12a that engages and comes into sliding contact with a and 12a.

The flange 10b at the top of the spherical seat 10 and the flange 12b at the top of the bearing sleeve 12 are connected via a damper 13. Furthermore, a support member 15 is engaged with the lower end of the bearing cylinder 10, which is slidably attached to the lower cylinder 10c of the spherical seat 10 and has a spring force applied toward the center of the bearing cylinder by a spring 14. In the figure, reference numeral 15a indicates a spring holder at the outer end of the support member 15, and the spring 14 is assumed to be a tension spring, with one end fixed to the spring holder 15.

The liquid contact part 3 includes a casing 16 that concentrically surrounds the rotating bowl 8, a receiver 17 provided on the upper part of the casing 16, and a casing 1.
A liquid supply pipe 18 that enters the casing 16 from the upper end of the container 6 and terminates near the inner bottom surface of the rotary bowl 8; a liquid drain pipe 19 that opens at the bottom surface of the receiver; a cleaning nozzle 20 having a nozzle opening 20a that spouts cleaning water toward the inner surface, a dispersion plate 21 provided near the lower end of the drive shaft 9, and a casing 16.
It has a drain 22 that opens at the center of the bottom surface. Further, a protruding steady rest 23 is provided on the lower surface of the slab 1 in close proximity to the rotating shaft 9.

In the centrifugal separator configured as described above, the unprocessed liquid containing solid particles supplied from the liquid supply pipe 18 is blown from the dispersion plate 21 to the inner circumferential surface of the rotary bowl 8, forming a liquid layer on the inner circumferential surface.

The solid particles in the liquid layer move toward the inner peripheral surface of the rotating bowl 8 due to centrifugal force and adhere thereto. On the other hand, the liquid enters the overflowing receiver 17 at the inner flange 8a at the upper end of the rotating bowl 8 and is recovered from the discharge pipe 19.

In addition, solid particles attached to the inner peripheral surface of the rotary bowl 8 may be removed by stopping the operation of the centrifuge periodically or irregularly, and removing the solid particles from the cleaning nozzle 2.
Spray cleaning water from 0 and drop it together with drain 2.
Discharge from 2.

Therefore, in the event of an emergency due to a disturbance such as an earthquake, a protruding steady rest 2 provided on a rotating bowl or a stationary part facing the rotating shaft is used.
3 acts as a stopper for the rotating bowl or rotating shaft that is shaken greatly due to the disturbance.

(Problem to be solved by the invention) In conventional vibration damping devices for centrifugal separators, if the damping effect of the bearing damper is expected too much, the damping constant of the damper tends to be set too high. Therefore, there was a problem in that unstable self-supporting vibrations occurred even in the steady rotation range.

In addition, if a protruding steady rest is provided on the stationary member facing the rotating bowl and this is used as a stopper against large swings of the rotating bowl or rotating shaft due to earthquakes, etc.,
Frictional force is generated due to the contact between the steady rest, the rotating bowl, and the rotating shaft, and a rotating force acting on the rotating bowl in the opposite direction to its rotational direction causes the rotating bowl to continue rotating without converging even after the disturbance has subsided. There is a problem of major damage to the bowl and rotating shaft.

The present invention has been made in order to solve the above-mentioned problems, and it prevents the occurrence of self-excited vibration in the steady rotational speed range of the rotating bowl and rotating shaft by setting the damping constant of the bearing damper within an appropriate range, and It is an object of the present invention to provide a vibration damping device for a centrifugal separator that can quickly and stably converge vibrations of a rotating bowl and a rotating shaft caused by disturbances such as the above.

[Structure of the Invention] (Means for Solving the Problems) The present invention includes a drive section above the slab, and a wetted section below the slab, which hangs down from the drive section, penetrates the slab, and reaches the lower end. A vibration damping device for a centrifugal separator including a rotating bowl and a rotating shaft rotatably supported by a bearing fixed part supported by a spherical seat fixed to the slab,
Features: A steady rest is provided on both upper and lower surfaces of the disc in a non-contact manner so as to sandwich a non-rotating disc provided in the bearing fixing part. If this occurs, the rotating bowl and rotating shaft will swing significantly, but the bearing fixed part will be damped by the steady rest before the rotating bowl and rotating shaft come into contact with the stationary member.
This vibration damping action also suppresses vibrations of the rotating bowl and rotating shaft. Therefore, the rotating bowl and rotating shaft never come into contact with the stationary member. Further, since the contact is made between the non-rotating parts, no turning force is generated due to frictional force, and no turning force is generated due to contact.

Furthermore, the gap between the steady rest and the non-rotating portion disk is maintained such that they contact each other before either the rotating shaft or the rotating bowl contacts the opposing stationary portion.

(Embodiment) An embodiment of a vibration damping device for a centrifugal separator according to the present invention will be described while referring to FIGS. 1 to 3.

The centrifugal separator disclosed in FIG. 1 has the same structure as the centrifugal separator shown in FIG. The explanation will focus mainly on the shaking device.

That is, the vibration damping device in FIG. It consists of a bottom rest 25 provided on the flange 10b of the fixed spherical seat 10. These vertical rests 24 and 25 are positioned above and below the non-rotating disk 12a of the bearing tube 12 without contacting them so as to sandwich the upper and lower surfaces of the non-rotating disk 12a.

The rest of the configuration is the same as that of the conventional example shown in FIG. 4, and the centrifugal separation operating means is also the same.

Next, the operation of the vibration damping device will be explained with reference to FIGS. 2 and 3.

It is assumed that the minimum gap between the rotating shaft 9 and the hole in the slab 1 is it, and the distance between this position and the spherical seat 10 and the bearing sleeve 12, that is, the center of the spherical bearing is .

Further, the distance between the center of the spherical bearing and the non-rotating disk 12a is defined as L2. Furthermore, the non-rotating disk 12a and each steady rest 24.2
5 is 12, and the swing width of the rotating shaft 9 is X.

Since the rotating shaft 9 can swing using the center of the spherical bearing as a support point,
The minimum gap between the rotating shaft 9 and the stationary slab 1 is J! If it swings by l, the tip of the bearing fixing part will be L2/L+
I can only roll a 7.

Therefore, the gap between the tip of the non-rotating disk 12a and the upper and lower steady rests 24,25, /! 2, the tip of the non-rotating disk 12a contacts the upper and lower steady rests 24.25 before the rotating shaft, so these steady rests 24.2
5 suppresses vibration and prevents the rotating shaft 9 from coming into contact with each other. Also, since the rotating bowl 8 does not come into contact with stationary members,
Not only does unstable vibration not occur due to contact, but there is also no damage, allowing stable operation.

[Effects of the Invention] According to the present invention, when the rotating bowl or the rotating shaft is greatly vibrated due to a disturbance such as an earthquake, the bearing can be fixed.

The vibrations can be quickly converged and a stable rotating state can be achieved without causing damage to the rotating bowl and rotating shaft. Therefore, it is possible to improve the reliability of the centrifuge and extend its life.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing a partial side view of an embodiment of a vibration damping device for a centrifugal separator according to the present invention, and FIG. 2 is a partial longitudinal sectional view for explaining the operation of the device in FIG. 1. Figure 3 is the second
FIG. 4 is a conceptual diagram showing the vibration state of the rotating shaft in the figure, and FIG. 4 is a longitudinal cross-sectional view showing a conventional vibration damping device for a centrifugal separator. 1...Slab 2...Drive part 3...Liquid contact part 4...Casing 5...Lower member 6...Motor 7...Upper member 8...Rotating bowl 9...・Rotating shaft 10... Spherical seat 11... Bowl bearing 12... Bearing sleeve 12a... Non-rotating disc 13... Damper 14... Spring 15... Support member 16... Casing 17...Receptor 18...Liquid supply pipe 20...Cleaning nozzle 21...Distribution plate 22...Drain 23...Steady rest 24...Upper rest 25...Downward rest (8733) Agent: Patent attorney Yoshiaki Inomata (1 idiot) Figure

Claims (1)

[Claims] A bearing is provided with a driving part above the slab and a wetted part below the slab, hanging from the driving part, passing through the slab, having a rotating bowl at the lower end, and supported by a spherical seat fixed to the slab. In a vibration damping device for a centrifugal separator having a rotating shaft rotatably supported by a fixed part, a non-rotating disc provided on the bearing fixed part is held between the upper and lower surfaces of the disc in a non-contact manner. A vibration damping device for a centrifugal separator, characterized in that each of the centrifuges is provided with a steady rest.