JPH04247251A - Solid-liquid separator - Google Patents

Abstract

PURPOSE:To prevent the divergence of the self-excited vibration of fluid and to stably operate a separation barrel at a revolving speed above the primary critical speed by freely rotatably hanging the barrel by a drive shaft like a pendulum and providing plural axial baffle plates on the inner face of the barrel. CONSTITUTION:The inside of a cylindrical casing 20 is vertically divided by a partition plate 21 into an upper chamber 22 and a lower separation chamber 23, and a cylindrical separation barrel 24 is set in the separation chamber 23. Plural axial baffle plates 27 are equidistantly arranged in the barrel 24 in the circumferential direction, the lower end plate 26 at the lower end of the barrel 24 is connected to a drive shaft 30 through a rib 28, and the shaft 30 is borne by the upper and lower bearings 35 and 36. In this case, a bearing housing 37 contg. the upper bearing 35 is freely vibrationally supported like a pendulum around the center O of the bearing, and a bearing housing 38 contg. the lower bearing 36 is supported through plural buffer mechanisms 41 in which a coil spring 39 and an oil damper 40 are provided in parallel.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Field of Industrial Application] The present invention relates to a solid-liquid separation device for purifying a liquid or recovering solids generated in a liquid such as crystallization. This invention relates to a centrifugal solid-liquid separator that separates solids.

0003

2. Description of the Related Art In the pharmaceutical, chemical, food, and other fields, it is frequently required to remove or recover solids suspended in liquids. A solid-liquid separator is used to separate, remove, and recover suspended solids, and such solid-liquid separation can be broadly classified into methods such as filtration, evaporative drying, and centrifugal sedimentation. Among these, the centrifugal sedimentation separation method has the advantage that unlike the filtration method, the filter does not clog and there is no need to replace the filter, and unlike the evaporative drying method, it does not require a heat source such as a heater, which is energy saving. It is widely used.

[0004] As a typical conventional centrifugal separator, there is one shown in FIGS. 9 and 10. Such centrifugal separation techniques include, for example, Japanese Unexamined Utility Model Publication No. 118541/1980, Japanese Unexamined Patent Publication No. 254856/1982, Japanese Unexamined Patent Publication No. 16064/1983, Japanese Unexamined Patent Publication No. 70157/1989, and Japanese Unexamined Patent Publication No. 1983/1999. 13
9160, Japanese Patent Publication No. 1-37181, etc. are known.

The centrifugal separator shown in FIGS. 9 and 10 shows a typical structure of a vertical axis cylindrical centrifugal separator. A cylinder 2 is housed therein, and an upper end plate 3 and a lower end plate 4 with holes are attached to the separation cylinder 2, so that centrifugal separation is performed within the separation cylinder 2.

The casing 1 is suspended from a plurality of support legs 5 via springs 6 and is elastically supported.

On the other hand, the lower end plate 4 of the separation barrel 2 is connected to a drive shaft 8 via a rib 7. The drive shaft 8 is rotationally driven by a motor drive device 9 such as an electric motor or a hydraulic motor. The rotating part of the drive shaft 8 is supported by a bearing housing 1 that is vertically installed in the casing 1.
This is done by bearing 11 in 0.

The casing 1 includes a liquid supply nozzle 12 for supplying the liquid to be treated into the separation cylinder 2, an outlet nozzle 13 for clear liquid,
A scraping blade 14 for scraping off the sedimented and separated cake, a moving device 15 such as an air cylinder for moving the scraping blade 14, and a cake discharge port 16 for discharging the scraped cake are provided. A washing liquid nozzle 17 for washing the cake is connected to the liquid supply nozzle 12.

[0009] This centrifugal sedimentation separator has a motor drive device 9
The separation cylinder 2 is raised to a predetermined rotational speed by the motor drive. A liquid to be treated is supplied to the lower part of the separation cylinder 2 through a liquid supply nozzle 12 . The supplied liquid to be treated is held on the inner surface of the separation cylinder 2 by centrifugal force.

The liquid to be treated held in the separation cylinder 2 is subjected to the action of rotational centrifugal force, and while flowing through the separation cylinder 2, solids with a large specific gravity are separated and settled on the peripheral wall surface of the separation cylinder 2. And it becomes a cake. The clarified liquid from which the solid content has been separated is shown in Figure 11.
As shown in FIG. 2, the liquid overflows from the upper end plate 3, travels along the inner peripheral surface of the casing 1, and is discharged from the outlet nozzle 13.

When a certain amount of the liquid to be treated is subjected to solid-liquid separation processing, a cake builds up on the inner surface of the separation cylinder 2, so the solid-liquid separation operation is stopped and a cake discharge operation is performed.

In this solid-liquid separation operation, if the liquid side contains an active ingredient, the active ingredient contained in the cake is recovered, and if the solid side contains an active ingredient, the liquid remaining in the cake is recovered. In order to expel it and increase its purity, a washing operation is often performed first.

In the water washing operation, after stopping the liquid supply, the separation cylinder 2
This is carried out by supplying the washing liquid from the washing liquid nozzle 17 while keeping it rotating. After the liquid to be treated in the separation cylinder 2 is replaced with the washing liquid, the rotation is stopped. Since the cake is usually crimped, it remains attached to the separation cylinder 2. Therefore, as shown in FIG.
Scrape off the cake adhering to the inner surface while slowly rotating the separation cylinder 2 using a The scraped cake is discharged to the lower part from the cake discharge port 16, and a series of solid-liquid separation operations is completed.

If the centrifugal separation operation is continued in this centrifugal separator, the amount of cake increases and an unbalance occurs, and the unbalanced force acting on the separation cylinder 2 increases. If an unbalanced force occurs, an excessive force acts on the bearing 11, which may cause damage to the device, so the entire device is supported by a spring 6 to absorb unbalanced vibrations.

[0015]

[Problems to be Solved by the Invention] Conventional centrifugal sedimentation separators have a simple configuration as shown in Figs. 9 and 10, so they are low in cost and easy to maintain, and are widely used. Separation performance for liquid separation was not necessarily sufficient. Particularly when the particle size is small or when the difference in specific gravity between solid and liquid is small, solid-liquid separation may be difficult.

The theoretical limit separation diameter for centrifugal solid-liquid separation is dp
Then, from Stokes' law,

[0017]

[Math 1]

It is expressed as:

Here, μ is the viscosity, Q is the flow rate, ρP is the specific gravity of solid particles, ρ is the specific gravity of the liquid, g is the gravitational acceleration, and Σ is the area of centrifugal sedimentation.

When the centrifugal sedimentation separator employs a cylindrical separation barrel, the centrifugal sedimentation separation area Σ is:

[0021]

[Math 2]

It is expressed as:

Here, π is the circumference, l is the axial length of the separation cylinder, ω is the rotational angular velocity, r2 is the radial length from the center of rotation to the inner surface of the separation cylinder (effective rotation radius), and r1 is the rotation This is the radial length from the center to the water surface inside the separation shell.

Equation (1) above indicates that particles with a particle size smaller than dp cannot be separated and are entrained in the clear liquid side. Even when the solid-liquid specific gravity difference ρP - ρ becomes small, dp increases, and as a result, entrainment to the clear liquid side increases.

In order to prevent this, it is effective to increase the length l, rotational angular velocity ω, and radius r2 according to equation (2). However, even if the length l is increased, the contribution to the centrifugal sedimentation separation area Σ is small because it is a first power, and it is better to increase ω or r2 to obtain a square effect.

However, in the conventional centrifugal sedimentation separator, it has been difficult to increase the rotational angular velocity ω and the effective rotational radius r2 of the separation barrel 2 for the following reasons.

(1) When the rotation angular velocity ω and the effective rotation radius r2 of the separation shell 2 are increased, the centrifugal force also increases, and the vibration caused by the unbalanced force also increases, and the load on the bearing 11 becomes excessive. Furthermore, since the entire device is elastically supported by the spring 6, the motor drive device 9 and the like are also subjected to excessive vibrations, which may cause a failure.

(2) In order to prevent vibrations caused by unbalanced forces, it is necessary to operate the rotating system at a speed exceeding the primary critical speed. When the primary critical speed is exceeded, the phase of displacement and centrifugal force is reversed by 180 degrees, and the centrifugal separator rotates around the center of gravity, making it less susceptible to unbalance. It is suitable for

However, when a rotating body containing fluid is rotated beyond the primary critical speed, there is a problem in that self-excited vibrations occur due to the internal fluid, and conventionally it has been impossible to rotate the rotating body at high speed.

[0030] December 1968 issue of “Transact
ions of the ASME, Journal
of Applied Mechanics”
The paper “Whirl Dynamics o
f aRotor Partially Filled
According to "With Liquid," pages 676 to 682, an unstable region due to fluid vibration (see Fig. 13) exists in a certain range where the ratio ω/ω0 between the rotational angular velocity ω and the test speed ω0 exceeds 1. Recent research has revealed that this unstable region exists over a fairly wide range, and the existence of this unstable region is the biggest bottleneck in improving the performance of centrifuges. .

(3) When the effective rotational radius r2 or the rotational angular velocity ω of the separation cylinder 2 is increased and the centrifugal force increases, the stress applied to the separation cylinder 2 due to its own weight and the liquid content increases. If this stress exceeds a certain value, there is a risk that the separation shell 2 will break and scatter, resulting in a major accident, so from this point of view as well, it was necessary to limit r and ω.

For the above three reasons, in the conventional centrifugal sedimentation separator, the circumferential velocity of the separation barrel 2, that is, r2 ×ω
It is necessary to suppress the peripheral speed to approximately 60 to 70 m/s or less, and if the peripheral speed of the separation cylinder 2 is suppressed to 60 to 70 m/s, the maximum
Only a centrifugal force of about 00G can be obtained, and satisfactory solid-liquid separation performance cannot be obtained.

Focusing on this point, a centrifugal separator as shown in FIG. 14 has been developed. This centrifugal separator has a large number of conical separation plates 1 in a separation barrel 2 housed in a casing 1.
8, thereby increasing the centrifugal sedimentation separation area Σ, which is called a "separation plate type". Figure 10 and Figure 1
The same reference numerals are given to the parts corresponding to 1, and the explanation thereof will be omitted.

This separating plate type centrifuge has an extremely complicated solid-liquid separation structure as shown in FIG. 14, so it is expensive, requires a lot of time and effort for maintenance such as maintenance and inspection, and is troublesome. Met.

[0035] In addition, conventional centrifugal sedimentation separators have poor cleaning efficiency for the cake, which is a solid content, and in particular, the solution contained between particles of the cake adhering to the inner surface of the separation cylinder is not easily replaced. Decrease in the recovery rate of active ingredients contained in
Alternatively, there was a problem of a decrease in the purity of solids due to solution mixing into the cake. These problems are particularly serious in the pharmaceutical industry, which handles expensive refined substances, and the nuclear industry, which handles nuclear raw materials, and effective countermeasures have been desired.

The present invention has been made in consideration of the above-mentioned circumstances, and provides a centrifugal sedimentation type solid-liquid separator that has a simple structure, provides high solid-liquid separation performance, and is capable of efficiently separating and recovering active ingredients. The purpose is to provide [Structure of the invention]

[0037]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the solid-liquid separator according to the present invention, as set forth in claim 1, includes a motor mount provided on a casing;
A motor drive device attached to the motor frame, a separation barrel housed in the casing and for centrifuging the liquid to be treated, and a separation barrel suspended from above, while the output side of the motor drive device a drive shaft flexibly connected to the drive shaft; a support device that supports the drive shaft so that it can rotate in a pendulum-like manner; and a spring element that provides a restoring force and a damping force that is provided between the drive shaft and the motor mount. A buffer device for providing a damping element, a liquid supply device for supplying the liquid to be treated into the separation cylinder, a device for discharging the clarified liquid, and a cleaning spray device for washing off the solid content that has settled and separated on the inner surface of the separation cylinder. A plurality of baffle plates extending in the axial direction are provided within the separation cylinder. Moreover, in order to solve the above-mentioned problem, the solid-liquid separator of the present invention is provided with an upper end plate and a lower end plate that allow the clarified liquid to overflow at the upper and lower ends of the separation cylinder, respectively, as described in claim 2. A toroidal liquid reservoir is recessed in the lower end plate, and a stirring blade for stirring the stored liquid and a liquid suction device for sucking out the stored liquid are provided in this liquid reservoir.

[0038]

[Operation] In the solid-liquid separator of the present invention, the separation barrel is suspended by a drive shaft so that it can rotate freely in a pendulum shape (for example, the primary critical speed of the rotating system is set to 5 Hz or less, and the secondary critical speed is set to the rated rotational speed). 120% or more, damping coefficient ratio in the range of 0.25 to 0.6), and has a simple structure with multiple axial baffle plates installed on the inner surface of the separation cylinder to prevent the divergence of fluid self-excited vibrations. However, it becomes possible to operate stably at a rotation speed exceeding the primary critical speed, improving solid-liquid separation performance and efficiently separating and recovering active ingredients.

Furthermore, when titanium or titanium alloy is used for the separation cylinder, the weight of the separation cylinder can be reduced and the circumferential speed of the separation cylinder can be further improved, so that the solid-liquid separation performance can be further improved. can be achieved.

Furthermore, by recessing the lower end surface of the separation barrel into a liquid reservoir and providing stirring blades for stirring the liquid stored in the liquid reservoir, the solid cake adhering to the separation barrel can be removed from the liquid reservoir. The liquid contained in the cake can be completely washed by spraying cleaning water into the cake and stirring.

[0041]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the solid-liquid separator according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a first embodiment in which the present invention is applied to a centrifugal sedimentation type solid-liquid separator. This solid-liquid separator has a cylindrical casing 20 installed on the floor or the like, and the inside of the casing 20 is vertically partitioned by a partition plate 21 into an upper chamber 22 and a separation chamber 23. A cylindrical separation barrel 24 is rotatably housed within the separation chamber 23 .

The separation shell 24 is made of titanium or titanium alloy (
Ti-6Al-4V alloy), while the separation shell 24
An upper end plate 25 and a lower end plate 26 are attached to the upper and lower ends, respectively. As shown in FIG. 2, a plurality of baffle plates 27, for example four baffle plates 27, extending in the axial direction of the separation cylinder 24 are provided at equal pitch intervals in the circumferential direction. Baffle plate 27
may be, for example, six or eight.

The lower end plate 26 of the separation barrel 24 is connected to a drive shaft 30 via a rib 28 and is integrated with the drive shaft 30. The drive shaft 30 extends upward through the upper chamber 22 and is connected via a flexible joint 33 to an output shaft 32 of a motor drive device 31 such as an electric motor or a hydraulic motor. The separation cylinder 24 is rotationally driven by a motor drive device 31. The upper part of the casing 20 functions as a motor pedestal on which a motor drive device 31 is installed.

The drive shaft 30 is rotatably supported by an upper bearing 35 and a lower bearing 36. For example, a self-aligning ball bearing is used as the upper bearing 35 to support the thrust load of the drive shaft 30. This upper bearing 3
5 is housed in an upper bearing housing 37 fixed to the top wall of the casing 20, and transfers the thrust load of the drive shaft 30 to the casing 20 through the upper bearing housing 37.
I am telling you. The upper bearing 35 constitutes a support device together with the upper bearing housing 31 so that the rotating system including the drive shaft 30 and the separation barrel 24 can be subjected to pendulum-like vibrations with the bearing center O as the rotation center.

On the other hand, a lower bearing 36 that supports the middle of the drive shaft 30 is housed within a bearing housing 38 thereof. The lower bearing housing 38 is not directly attached to the casing 20, but rather has a plurality of buffer mechanisms 41 in which coil springs 39 and oil dampers 40 are arranged side by side.
Attached via.

The coil spring 39 of the buffer mechanism 41 is
The spring constant is selected so that the primary critical speed of the entire rotating system (drive shaft 30 and separation cylinder 24) is 5 Hz or less, preferably 3 Hz or less. Further, the damping constant C of the oil damper 40 has a damping coefficient ratio ζ of 0.25 to
It is selected so that it falls between 0.6 and 0.6.

[0048] The damping coefficient ratio ζ is

[0049]

[Math 3]

It is expressed as:

Here, M is the total mass of the separation barrel including the liquid and cake, L is the distance from the rotation center O to the gravity center G of the separation barrel, and ls is the distance from the rotation center to the oil damper and coil spring 29. Show distance. Note that in equation (3), the mass of the drive shaft 30 is ignored for simplification.

Partition plate 21 located below lower bearing 36
This prevents the mist of the liquid to be processed from scattering into the upper chamber 22, and a steady rest 43 made of a soft material such as plastic is installed on the inner peripheral surface of the opening of the partition plate 21 through which the drive shaft 30 passes. is installed. This steady rest 43
has a function of suppressing excessive vibration of the drive shaft 30.

Separation barrel 24 housed in separation chamber 23
A liquid supply nozzle 44 as a liquid supply device and a cake cleaning spray pipe 45 as a cleaning spray device extend inside the casing 20 from the outside. The liquid supply nozzle 44 enters the separation cylinder 24 from the opening side of the upper end plate 25 of the separation cylinder 24, and enters the separation cylinder 24 from the opening side of the upper end plate 25 of the separation cylinder 24.
It terminates near 6 and is open. Similarly to the liquid supply nozzle 44, the cake cleaning spray pipe 45 also enters the separation cylinder 24 from the opening side of the upper end plate 25, and in this separation cylinder 24, a plurality of cakes are sprayed toward the inner peripheral surface of the cylinder. A cleaning spray 46 is provided. Reference numeral 47 is a washing liquid nozzle.

The casing 20 also has an outlet nozzle 48 for guiding a clarified liquid obtained by separating and removing solids from the liquid to be treated, and a sludge opening 4 for discharging the separated solids.
9 is provided.

Next, the solid-liquid separation action of this solid-liquid separator will be explained.

The operation of the solid-liquid separator is started by driving the motor drive device 31, and this motor drive causes the separation cylinder 24 to rotate at a predetermined rotational speed, for example, at a rotational angular velocity ω=6.
30rad/sec. increase to a certain extent. The effective rotation radius (inner radius) r2 of the separation barrel 24 is, for example, 0.2 m.

When the solid-liquid separator starts operating, the liquid to be treated is supplied to the lower part of the separation cylinder 24 by the liquid supply nozzle 44. The supplied liquid to be treated is held on the inner surface of the separation cylinder 24 by the centrifugal force caused by the rotation of the separation cylinder 24 and the assistance of the baffle plate 27 .

The liquid to be treated held in the separation barrel 24 is subjected to the action of rotational centrifugal force, and while flowing through the separation barrel 24, solids with a large specific gravity are separated and settled on the inner wall surface of the separation barrel 24. And it becomes a cake. The clarified liquid from which the solid content has been separated overflows through the opening in the upper end plate 25 and flows into the casing 2.
0 and the separation cylinder 24 and is discharged to the outside from the clarified liquid outlet nozzle 48.

When a certain amount of the liquid to be treated is subjected to solid-liquid separation processing, the amount of cake adhering to the inner surface of the separation cylinder 24 increases, so the solid-liquid separation operation is stopped and a cake discharge operation is performed.

This cake discharging operation is carried out by supplying high-pressure water into the cake cleaning spray pipe 45 as a cleaning spray device.
High-pressure water is sprayed onto the inner peripheral surface of the separation cylinder 24 by the cake cleaning spray 46. By this spraying, the separation cylinder 24
This is designed to wash away cake adhering to the inner circumferential surface of the pipe.

In this solid-liquid separator, the separation cylinder 24
Since the cake adhering to the inner surface is washed off by spraying high-pressure water using the cake cleaning spray 46, there is no need for conventional scraping blades. Therefore, the baffle plate 27 can be attached to the inner peripheral surface of the separation cylinder 24.

By providing the baffle plate 27 on the separation cylinder 24, the following advantages can be obtained.

(a) The rotational angular velocity ω of the separation shell 24 and the rotational angular velocity of the liquid inside the separation shell 24 become equal. If the baffle plate 27 is not provided, it takes time for the supplied liquid to be processed to be accelerated by the separation cylinder 24, so the liquid to be processed will rotate later than the separation cylinder 24, but the baffle plate 2
By installing 7, it will be accelerated quickly and there will be no lag. Therefore, it is possible to reduce the loss of separation performance from the theoretical value due to the rotation delay.

(b) Ripples inside the separation cylinder 24 can be prevented.

[0065] Transactions of the Japan Society of Mechanical Engineers (C edition) Volume 49, 439
According to the paper "Study on free surface waves of a liquid partially contained in a rotating cylindrical container" by Shigehiko Kaneko et al. published on pages 370 to 378 of the issue, self-excited vibrations caused by fluids are It is said that this is caused by the undulation of the internal fluid in various modes as shown in Fig. 3.

Therefore, by inserting the baffle plate 27 inside the separation shell 24, it is possible to considerably suppress the ripples caused by the internal fluid, which is effective in reducing self-excited vibrations. According to our research, the ripples of internal self-excited vibration shown in Fig. 3 have order m
It was found that modes with small values are more likely to occur, and higher-order modes almost never occur. Therefore, if the number of baffle plates 27 is set to 4 or more, the order m=3
It is effective against the following waves.

Next, the drive shaft 3 of the solid-liquid separator
0 was supported so that it could rotate like a pendulum, and tests were conducted with various parameters changed.

The coil spring 39 is configured so that when the separation barrel 24 has a primary critical speed of 5 Hz or less, the secondary critical speed is 1 of the rated rotation speed.
A spring constant of 20% or more was selected. It was found that by this selection, the range in which self-excited vibration of the fluid occurs is extremely limited.

To illustrate the test results, (1) In a test in which a spring constant of 15 Hz was selected for the primary critical speed, self-excited vibration occurred despite the presence of the baffle plate 27.
Extremely strong vibrations occurred at frequencies above 45Hz and 45Hz, making it impossible to operate.

(2) If the coil spring 39 is changed so that the primary critical speed is 5Hz, the
Although weak self-excited vibrations occurred at 15 Hz or higher, no divergence of self-excited vibrations occurred at frequencies above 15 Hz.

Based on the results of these series of tests, the damping coefficient ratio range of 0.25 to 0.6 was found as the optimum value for the damping constant of the oil damper. By setting this damping coefficient, it is possible to suppress self-excited vibrations of 10 to 15 Hz to a level that does not cause any problems, and to suppress the bearing load at high speed rated rotation to a small level.

Furthermore, within this range of damping coefficient ratio,
Since the reaction force that acts on the bearing when passing through critical speeds, where the amplitude is maximum, can be minimized, it is possible to significantly improve reliability and extend life compared to conventional bearings.

Figure 4 shows the relationship between the damping coefficient ratio and the bearing reaction force when passing the primary critical speed. It can be confirmed that the bearing reaction force is minimal.

Note that the drive shaft 30 is of a hanging type and has a small primary critical speed, so for safety in the event that the amplitude becomes excessive, the steady rest 4
The structure is limited by 3.

Furthermore, the separation cylinder 24 is made of titanium alloy (Ti-
6Al-4V), the specific gravity can be reduced to about half that of conventional stainless steel separation cylinders, and it can withstand high-speed rotation, which was previously impossible.

In the solid-liquid separator shown in FIGS. 1 and 2, there are four baffle plates 27 in the separation barrel 24, the primary critical speed is 5 Hz or less, and the secondary critical speed is 1 Hz of the rated rotation speed.
It has been found that by selecting a damping coefficient ratio of 20% or more and a damping coefficient ratio in the range of 0.25 to 0.6, fluid self-excited vibration can be suppressed and the load due to vibration applied to the bearing etc. can be minimized.

Furthermore, by making the separation cylinder 24 made of titanium alloy, the rotational angular velocity ω can be reduced to 310 rad/sec as compared to the conventional one.
．． from 625rad/sec. It became possible to double the amount. By increasing the rotation speed, centrifugal force can be increased, and solid-liquid separation performance can be significantly improved (
The separation performance is proportional to the square of ω, so it is about 4 times that of the conventional method.)

FIG. 5 shows a second embodiment of the solid-liquid separator according to the present invention.

This solid-liquid separator has a cylindrical casing 20.
A separation chamber 23A formed inside A houses a separation cylinder 24A made of pure titanium. An upper end plate 25A and a lower end plate 26A are attached to the separation barrel 24A. Lower end plate 2
A toroidal liquid reservoir 50 is recessed in 6A. Unlike the solid-liquid separator shown in FIG. 1, a cake discharge port is not formed in this lower end plate 26A.

Inside the separation cylinder 24A, a plurality of baffle plates 27A, for example four, extending in the axial direction are provided at equal pitches in the circumferential direction of the separation cylinder 24A.

On the other hand, the central boss portion of the lower end plate 26A is supported by the drive shaft 30A. Drive shaft 3
0A is integrally joined to an upper shaft 52 via a flange shaft joint 51, and these shafts 30A, 52 and separation barrel 24A constitute a rotating system.

In the rotating system, the thrust load is supported by an upper bearing 35A such as an upper angular bearing, and the radial load is supported by both the upper bearing 35A and the lower bearing 36A. Each bearing 35A, 36A is housed in a cylindrical (sleeve) bearing housing 54, and this bearing housing 54 is supported by a motor mount 56 via a spherical bearing 55.
It is designed to be able to freely oscillate pendulum-like around the spherical bearing 55 at the center O. The motor stand 56 has a casing 20A
installed on top.

A motor drive device 31A such as an electric motor or a hydraulic motor is installed on the motor stand 56, and an output shaft 32A from the motor drive device 31A is connected to the flexible joint 3.
It is connected to the upper shaft 52 via the flexible joint 33A, and transmits rotational force to the upper shaft 52 through the flexible joint 33A.

On the other hand, the bearing housing 54 is equipped with a shock absorber 41 consisting of a coil spring 39A and an oil damper 40A.
It is elastically supported by the motor frame 56 via A. The spring constant of the coil spring 39A and the damping constant of the oil damper 40A are set similarly to the solid-liquid separator shown in FIGS. 1 and 2.

Further, inside the separation cylinder 24A, there are provided a liquid supply nozzle 44A as a liquid supply device, a cake cleaning spray pipe 45A and a cake cleaning spray 46A as cleaning spray devices, and a liquid reservoir on the lower end plate 26A. A plurality of sludge suction pipes 58 are provided within the sludge 50 as liquid suction devices. A stirring blade 59 is attached to the tip of this suction pipe 58.

The sludge suction pipe 58 moves upward within the separation cylinder 24A and the guide cylinder 60, is bent radially outward from above the separation cylinder 24A, and then exits the casing 20A.
The whole is bent into an inverted U shape, and the other end is guided to an airtight sludge collection can 61 provided at a level lower than the liquid reservoir 50. The pressure inside the recovery can 61 is reduced by a vacuum pump (not shown) or the like through a pressure reducing pipe 62 .

In the solid-liquid separator shown in FIG. 5, for example, when the effective radius of rotation r2 of the separation cylinder 24A is set to 0.45 m and the rotational angular velocity ω is set to 210 rad/s, the circumferential speed of the separation cylinder 24A is 95 m/sec. It will be about.

FIG. 6 shows an example of setting the spring constant of the coil spring 39A used in the solid-liquid separator shown in FIG.

The graph in FIG. 6 shows the spring constant of the coil spring 39A on the horizontal axis and the natural frequency of the rotating system on the vertical axis. indicates a dangerous speed.

In this embodiment, the primary critical speed is set to 3 Hz or less. In this case, the spring constant k of the coil spring 39A may be approximately 7×10 2 kgf/mm. On the other hand, since the rotational speed of the separation cylinder 24A is approximately 34 Hz, the spring constant at which the secondary critical speed is 34×1.2=40.8 Hz or higher is approximately 102 kgf/mm. Therefore, it is only necessary to select the optimum value between this period.

FIG. 7 shows a comparison of the required plate thicknesses of conventional stainless steel and titanium of this embodiment when the stress of the separation cylinder 24A is set to a constant value. As can be seen from Figure 7, in the case of stainless steel, the required plate thickness increases rapidly above 1900 rpm, making it unusable, but in the case of titanium, this rising point moves up to about 2600 rpm, and the effective gender is obvious.

[0092]The solid-liquid separator shown in FIG. 5 also has substantially the same effects as the solid-liquid separator shown in FIG. The effects of the baffle plate 27A, rotating coil spring 39A, and oil damper 40A are also the same.

In the solid-liquid separator shown in FIG.
Since a liquid reservoir 50 and a stirring blade 59 are provided on the lower end plate 26A of A, the effects of the liquid reservoir 50 and stirring blade 59 will be explained.

After processing a certain amount of the liquid to be treated, the separation cylinder 24A
When cake accumulates inside, first slowly stop the rotation. The cake remains attached to the inner wall surface of the separation cylinder 24A,
The supernatant liquid falls into the liquid reservoir 50. This supernatant liquid is sucked up by one of the plurality of sludge suction pipes 58,
It is collected in a collection can 61. At this time, the recovery can 61 is depressurized from the pressure reducing pipe 62 using a vacuum pump or the like.
The sludge suction pipe 58 acts as a siphon and can smoothly transfer the liquid to the collection can 61. Since the recovered liquid contains solid content (and active ingredients), it is returned to the liquid to be treated tank through a return line (not shown).

Next, while slowly rotating the separation cylinder 24A by the motor drive device 31A, the cake cleaning spray 4 is applied.
6A injects high-pressure water toward the inner surface of the separation cylinder 24A. As a result, the cake is peeled off and falls into the liquid reservoir 50 together with the washing water. After the separation cylinder 24A has rotated once or twice and all the cakes have fallen, the rotation of the motor drive device 31A is increased to 10 to 40 rpm.

[0096] Since the stirring blade 59 provided in the liquid reservoir 50 is fixed to the casing 20A, the liquid rotates,
It will be stirred. By this stirring, the liquid to be treated contained in the particle can of the cake is washed.

Next, the rotation of the separation cylinder 24A by the motor drive device 31A is increased to the rated high speed rotation. At this time,
The wash water and solids in the liquid reservoir 50 ascend the slope 50a forming the side surface of the liquid reservoir, and are subjected to centrifugal sedimentation separation again within the separation cylinder 24A.

[0098] This operation is continued for a time A(
(usually for 5 to 10 minutes) to form a cake on the inner wall of the separation cylinder 24A.

Next, the rotation of the separation cylinder 24A is stopped, and the cleaning water that has fallen into the liquid reservoir 50 is sucked up by the sludge suction pipe 58 and returned to the liquid tank to be treated by the return line. Subsequently, while slowly rotating the separation cylinder 24A, the cake is dropped into the liquid reservoir 50 by the cake cleaning spray 46A. Almost no components of the liquid to be treated remain in this cake. Therefore, while rotating at 10 to 40 rpm and stirring, the solid matter in the form of slurry is sucked up by another sludge suction pipe 58 and collected into the collection can 61 .

[0100] By performing the above solid-liquid separation operation,
(1) The components of the liquid to be treated contained in the solid cake can be completely washed away and the purity of the solid content can be increased, while (2) the active ingredients are contained in the liquid to be treated. If there is, you can reduce the amount entrained in the cake,
The recovery rate of active ingredients can be increased.

[0101] Therefore, it can be used particularly for purposes requiring the recovery of trace amounts of active ingredients such as drugs and nuclear raw materials.

[0102] Although the cake washing operation was carried out once in this example, if it is insufficient, this may be repeated several times.

FIG. 8 shows a third embodiment of the solid-liquid separator according to the present invention.

The solid-liquid separator shown in this example is substantially the same as the one shown in FIG. 5 except for the following configuration, so corresponding parts are designated by the same reference numerals and a description thereof will be omitted.

The solid-liquid separator shown in FIG. 8 differs from the solid-liquid separator shown in FIG. 5 in the support structure of the bearing housing 54. The bearing housing 54 is not a spherical bearing, but is elastically supported by the motor mount 56 via a hollow cylindrical thick rubber bush 64 as a shock absorber. This motor stand 56 can be installed on a general stand 65. Bearing housing 5
By using a rubber bush 64 to support 4, a coil spring or an oil damper can be eliminated. This rubber bush 64 serves both as a support device and a shock absorber for the drive shaft 30A. Since the rubber bushing 64 originally includes a spring element and a damping element, it is possible to eliminate the coil spring and oil damper. The material specifications, thickness, diameter, etc. of the rubber bush may be designed in accordance with the solid-liquid separator shown in FIG. 5 so as to obtain an appropriate spring constant and damping constant.

[0106] By adopting the rubber bush 64 to support the bearing housing 54, this solid-liquid separator (1) eliminates the need for springs, dampers, and spherical bearings, resulting in an extremely simple structure and ease of maintenance. (2) There is no need to inject lubricant into spherical bearings or change oil in oil dampers, resulting in maintenance-free operation.

(3) Since the entire structure is supported by rubber, it is possible to suppress even minute noises and vibrations generated by the bearings, resulting in quieter operation.

(4) The number of mechanical parts can be reduced and the weight can be reduced.

(5) Since the generation of noise can be suppressed and the weight can be reduced, it can be installed on the pedestal 65, etc., and the installation locations can be expanded.

[0110]

Effects of the Invention As described above, in the solid-liquid separator according to the present invention, the separation barrel is suspended by the drive shaft so as to be freely rotatable in a pendulum-like manner, and the separation barrel has a structure that extends in the axial direction on the inner surface of the separation barrel. It has a simple configuration with only a baffle plate installed, which prevents the dispersion of fluid self-excited vibrations, enables stable operation at rotation speeds exceeding the primary critical speed, and improves the rotation speed of the separation barrel. Because you can
Solid-liquid separation performance can be improved, and active ingredients can be efficiently separated and recovered.

[0111] Furthermore, since a cleaning spray device is provided on the inner surface of the separation cylinder to wash off the solids that have settled and separated, the washing and cleaning of the solids can be carried out smoothly and efficiently.

[0112] Furthermore, when titanium or a titanium alloy is used for the separation cylinder, the weight of the separation cylinder can be reduced, the circumferential speed of the separation cylinder can be further improved, and the solid-liquid separation performance can be further improved. be able to.

Furthermore, by recessing the lower end surface of the separation barrel into a liquid reservoir and providing stirring blades for stirring the liquid stored in the liquid reservoir, the solid cake adhering to the separation barrel can be removed from the liquid reservoir. The liquid contained in the cake can be completely washed by spraying cleaning water into the cake and stirring.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a solid-liquid separator according to the present invention.

FIG. 2 is a plan cross-sectional view taken along line II-II in FIG. 1;

FIG. 3 (A), (B), (C), and (D) are diagrams showing internal flow states of self-excited vibration of fluid according to orders.

FIG. 4 is a graph showing the relationship between damping coefficient ratio and bearing reaction force when passing through a critical speed.

FIG. 5 is a longitudinal sectional view showing a second embodiment of the solid-liquid separator according to the present invention.

FIG. 6 is a graph for determining the spring constant of a coil spring in the solid-liquid separator shown in FIG. 5;

FIG. 7 is a graph showing the required plate thickness when changing the material of the separation cylinder.

FIG. 8 is a vertical cross-sectional view showing a third embodiment of the solid-liquid separator according to the present invention.

FIG. 9 is a vertical cross-sectional view of a centrifugal sedimentation separator showing a conventional solid-liquid separation device.

FIG. 10 is a plan cross-sectional view taken along line XX in FIG. 9;

FIG. 11 is a diagram showing the operation of the centrifugal sedimentation separator shown in FIG. 9.

FIG. 12 is a diagram showing the operation of the centrifugal sedimentation separator in FIG. 9.

FIG. 13 is a diagram showing a rotationally unstable region due to self-excited vibration of fluid.

FIG. 14 is a diagram showing another example of a conventional sedimentation separator.

[Explanation of symbols]

20, 20A Casing 21 Partition plate 24, 24A Separation barrel 25, 25A Upper end plate 26, 26A Lower end plate 27, 27A Baffle plate 28 Rib 30, 30A Drive shaft 31, 31A Motor drive device 32 Output shaft 33, 33A Flexible joint 35 Upper part Bearing 36 Lower bearing 37 Upper bearing housing 38 Lower bearing housing 39, 39A Coil spring 40, 40A Oil damper 41, 41A Buffer mechanism 43 Steady rest 44 Liquid supply nozzle (liquid supply device) 45, 45A Cake cleaning spray pipe (cleaning spray device) ) 46, 46A Cake cleaning spray (cleaning spray device) 48 Outlet nozzle (clarified liquid discharge device) 50 Liquid reservoir 52 Upper shaft 54 Bearing housing 55 Spherical bearing 56 Motor frame 58 Sludge suction pipe (liquid suction device) 61 Recovery Can 62 Decompression tube

Claims (2)

[Claims] [Claim 1] A motor mount provided on a casing, a motor drive device attached to the motor mount,
A separation cylinder housed in the casing and through which a liquid to be treated is centrifuged; a drive shaft that suspends the separation cylinder from above and is flexibly connected to the output side of the motor drive device; and the drive shaft. a support device that supports the motor so that it can rotate in a pendulum-like manner; a buffer device that provides a spring element that provides a restoring force and a damping element that provides a damping force between the drive shaft and the motor mount; a baffle that extends in the axial direction within the separation cylinder, and includes a liquid supply device that supplies the liquid to be treated, a device that discharges the clarified liquid, and a cleaning spray device that washes away solids that have settled and separated on the inner surface of the separation cylinder. A solid-liquid separator characterized by having a plurality of plates. [Claim 2] An upper end plate and a lower end plate are respectively provided at the upper and lower ends of the separation cylinder to allow the clarified liquid to overflow, and a torus-shaped liquid reservoir is recessed in the lower end plate, and the stored liquid is stirred in this liquid reservoir. 2. The solid-liquid separator according to claim 1, further comprising a stirring blade for stirring the liquid and a liquid suction device for sucking out the stored liquid.