WO2018008490A1 - Centrifugal separator and centrifugal separation method - Google Patents

Abstract

A centrifugal separator equipped with a cylindrical basket (2) which rotates around an axis (O) and has a filtration screen (2a) provided in the body section thereof, and also equipped with an extrusion plate (7) which is housed inside the basket (2) and capable of integrally rotating with the basket, and is also capable of moving relative to the basket (2) in the axial (O) direction, wherein when discharging a cake that has been filtered by a filtration screen (2a) from a substance to be treated that was supplied to the interior of the basket (2) by extruding the cake from the opening end (2b) side of the basket (2) using the extrusion plate (7), the relative movement speed in the axial (O) direction between the extrusion plate (7) and the basket (2) is set in a manner such that the relative movement speed in the direction which causes the distance (D) in the axial (O) direction between the extrusion plate (7) and the opening end (2b) of the basket (2) to increase is slower than the relative movement speed in the direction which causes said distance (D) to decrease.

Description

Centrifuge and centrifuge method

In the present invention, a processed product supplied in a basket rotated around an axis is filtered by a filter screen provided in a body portion of the basket, and a cake filtered from the processed product is accommodated in the basket. The present invention relates to an extrusion-type centrifuge device and a centrifuge method for discharging from an open end of a basket by an extrusion plate that can rotate integrally and move relative to the basket in the axial direction.
This application claims priority based on Japanese Patent Application No. 2016-133665 for which it applied to Japan on July 5, 2016, and uses the content here.

As such an extrusion-type centrifuge, for example, Patent Document 1 discloses an outer basket that is rotated around an axis, and is coaxially disposed in the outer basket and rotated integrally with the outer basket. A two-stage basket type centrifuge having an inner basket that is advanced and retracted in a direction is disclosed. In this two-stage basket type centrifuge, a processed product to be filtered by centrifugation is supported by the outer basket and is disposed in the inner basket so as to face the opening of the processed product supply pipe; It supplies between this extrusion board and the annular plate-like distributor arrange | positioned so that the opening part of a processed material supply pipe may be surrounded.

In such a centrifugal separator, the processed material supplied between the extrusion plate and the distributor from the opening of the supply pipe is deposited on the inner peripheral surface of the filtration screen provided on the barrel of the inner basket by centrifugal force. While being filtered, a cake is formed. Further, the cake accumulates also in the axial direction of the inner basket by the advance of the inner basket toward the opening end side of the outer basket. Next, the cake of the processed product is pushed out by the extrusion plate by the retraction of the inner basket with respect to the outer basket and discharged to the inner peripheral surface of the outer basket. In addition, the cake of the processed product thus discharged onto the inner peripheral surface of the outer basket is further filtered by the filtration screen of the outer basket, pushed out by the advance of the inner basket, and discharged from the open end of the outer basket.

Japanese Laid-Open Patent Publication No. 2014-091093

In such a centrifugal separator, the relative movement of the basket and the extrusion plate in the axial direction (in the centrifugal separator described in Patent Document 1, the advance and retreat of the inner basket with respect to the extrusion plate) is generally a hydraulic pressure by a hydraulic piston. By driving. Therefore, the moving speed at the time of forward movement and the moving speed at the time of backward movement are usually equal. Further, the supply amount of the processed material from the supply pipe is usually a constant amount per unit time.

When the inner basket moves forward with respect to the extruded plate, the processed product is supplied to the filter screen that is relatively easy to be filtered after the processed material deposited on the inner peripheral surface of the filter screen of the inner basket is pushed out by the extruded plate. The On the other hand, when the inner basket moves backward with respect to the extruded plate, the processed product is supplied so as to be placed on the cake of the processed product that is deposited on the inner peripheral surface of the filtration screen of the inner basket and being pushed out by the extruded plate. Therefore, the processed product is difficult to be filtered.

For this reason, especially when a processed material that is difficult to filter is supplied, if the centrifugal separator is not enlarged, such as increasing the capacity of the basket, the processed material may not be sufficiently filtered when the inner basket is retracted, In some cases, it is difficult to form a simple cake, and it is necessary to limit the supply amount of the processed product.

In contrast to the centrifugal separator described in Patent Document 1, the position of the basket in the axial direction is fixed, and the extruded plate accommodated in the basket advances and retreats in the axial direction with respect to the basket. Centrifugal separators that can be moved by the above are also known. In such a centrifugal separator, when the extruded plate moves backward, the processed product is supplied to a filter screen that is easily filtered after the cake of the processed product is extruded. On the other hand, when the extruded plate moves forward, the processed product supplied to the cake of the processed product being pushed out by the extruded plate is added. Therefore, filtration and cake formation are insufficient.

The present invention is made under such a background, and promotes efficient filtration of a processed product without increasing the basket capacity or the like, thereby increasing the throughput and forming a uniform cake. It is an object of the present invention to provide a centrifuge device and a centrifuge method.

A first aspect of the centrifugal separator according to the present invention includes a cylindrical basket provided with a filtration screen in a body portion and rotated around an axis, and accommodated in the basket and rotatable integrally with the basket. And an extrusion plate provided so as to be relatively movable in the axial direction, and the cake filtered by the filtration screen from the processed material supplied in the basket is extruded to the open end side of the basket by the extrusion plate and discharged. A separation device, wherein the relative movement speed in the axial direction of the extrusion plate and the basket is such that the relative movement speed in the direction in which the axial distance between the extrusion plate and the opening end of the basket increases becomes larger than the opening end of the extrusion plate and the basket. Is set so as to be smaller than the relative movement speed in the direction in which the interval in the axial direction becomes smaller.

In the first aspect of the centrifugal separation method of the present invention, the processed product is supplied into a cylindrical basket that is provided with a filtration screen in the body portion and rotated around the axis, and is filtered from the processed product by the filtration screen. This is a centrifugal separation method in which the cake is pushed out to the open end side of the basket and discharged by an extrusion plate that is housed in the basket and can be rotated together and moved relative to the basket in the axial direction. The relative movement speed in the axial direction between the extrusion plate and the basket is the relative movement speed in the direction in which the axial distance between the extrusion plate and the basket opening end increases, and the axial movement between the extrusion plate and the basket opening end. It is set to be smaller than the relative movement speed in the direction in which the direction interval becomes smaller.

In the first aspect of such a centrifugal separator and the first aspect of the centrifugal method, for example, as in the centrifugal separator described in Patent Document 1, the extruded plate is at a fixed position in the axial direction, and the basket is When it is possible to move by moving back and forth in the axial direction, the direction in which the axial distance between the extrusion plate and the open end of the basket increases becomes the direction when the basket moves forward, and the direction in which this distance decreases becomes smaller. The direction when the basket moves backward. On the other hand, when the basket is at a fixed position in the axial direction and the extruded plate is movable back and forth in the axial direction, the direction in which the axial distance between the extruded plate and the open end of the basket increases is This is the direction when the extruded plate moves backward, and the direction in which the interval decreases is the direction when the extruded plate moves forward.

That is, in the first aspect of the centrifugal separator and the first aspect of the centrifugal method configured as described above, when one of the basket and the extrusion plate moves relative to the other, the inner peripheral surface of the filtration screen of the basket The relative movement speed when the processed material is supplied to the filter screen that is relatively easy to be filtered after the processed material deposited on the extrusion plate is extruded by the extrusion plate is difficult to be filtered. It is smaller than the relative movement speed when the processed material is supplied to the filtration screen in the state.

For this reason, even if the supply amount of the processed material is increased when the capacity of the basket is the same, more processed material can be supplied to the filtration screen of the basket that is easily filtered. On the other hand, when the relative movement speeds in the forward and backward movements of the relative movement are set in this manner and the time of one stroke of the forward and backward is the same, the processed material is supplied to the filtration screen that is difficult to be filtered. The relative movement speed at the time of being processed becomes larger than the relative movement speed at the time when the processed material is supplied to the filtration screen in a state of being easily filtered. Therefore, the supply amount of the processed product added to the processed cake remaining on the filter screen is reduced, and a uniform cake can be formed.

Therefore, according to the centrifuge and the centrifuge method having the above-described configuration, it is possible to filter more processed materials without enlarging the capacity of the basket and increasing the time for one stroke of advancement / retraction. While being supplied to the filter screen in a state where it is easy to be filtered, the supply amount of the processed material supplied to the filter screen in a state where filtering is difficult can be suppressed. For this reason, it is possible to increase the throughput by efficiently filtering the processed product, and to promote the formation of a uniform cake.

The relative movement speed in the axial direction of the extruded plate with respect to the basket is the relative movement speed in the direction in which the distance between the extruded plate and the open end of the basket increases in the axial direction. When the ratio is set to be smaller than the speed, if the ratio is too large, it is difficult to set the relative movement speed with respect to one of the basket and the extruded plate. For this reason, there is a possibility that a large amount of processed material cannot be reliably supplied to the filtration screen that is easily filtered.

For this reason, the relative movement speed in the direction in which the axial distance between the extruded plate and the open end of the basket increases is such that the axial distance between the extruded plate and the open end of the basket decreases. It is desirable to set it to 1/4 or more of the relative movement speed. However, even if the ratio of these relative movement speeds is close to 1 and the speed difference is too small, there is a possibility that the above-described operation cannot be effectively achieved. Therefore, it is more desirable to set the relative movement speed in the direction in which the interval increases to 2/3 or less of the relative movement speed in the direction in which the interval decreases.

It should be noted that the setting of the relative moving speed of advance / retreat can be applied to the case where, for example, one of the basket and the pushing plate is moved forward and backward with respect to the other by hydraulic driving by a conventional hydraulic piston. In that case, there may be a difference in the hydraulic fluid flow path diameter between forward and reverse, a speed controller may be installed, or a difference in the hydraulic oil discharge speed may be provided by bypassing the cylinder discharge side flow path. That's fine. In this case, the hydraulic pressure becomes unstable when switching between advance and retreat, and it may be difficult to set the predetermined relative movement speed.

Therefore, for driving one of the basket and the extrusion plate, for example, the rotation of an electric motor (servo motor) transmitted to a screw shaft such as a ball screw is screwed onto a screw shaft by screwing a nut coaxially attached to the piston rod. It is possible to use a so-called electric cylinder that converts to linear movement of the rod. Furthermore, a linear cylinder that linearly moves the piston rod directly by an electric linear motor can be used. Alternatively, two or more chains are engaged with each other and fed out in a column shape by an electric motor and moved forward, and the chain is unwound and pulled back and moved backward to move linearly. It is desirable to use a high electric motor.

As described above, according to the present invention, the processing volume can be efficiently filtered without increasing the basket capacity to increase the size of the basket or increasing the time for one stroke of advancement / retraction. While aiming at an increase, a uniform cake can be formed. Therefore, it is possible to reduce the cost of the centrifuge device itself, reduce the installation space of the device, simplify the installation base by reducing the weight of the device, and stably and easily perform post-processing of the cake. It becomes possible.

It is sectional drawing which shows the outline of 1st Embodiment of the centrifuge of this invention. In the embodiment shown in FIG. 1, it is an expanded sectional view of the basket periphery showing a state in which the inner basket is retracted with respect to the push plate (a state in which the axial distance between the push plate and the open end of the basket is small). In the embodiment shown in FIG. 1, it is an expanded sectional view of the basket periphery showing a state in which the inner basket has advanced with respect to the push plate (a state in which the distance between the push plate and the open end of the basket in the axial direction is large). In 2nd Embodiment of the centrifuge of this invention, the expanded cross section around a basket which shows the state (state in which the space | interval of the axial direction of an extrusion plate and the opening end of a basket is small) which the extrusion plate advanced with respect to the basket FIG. FIG. 5 is an enlarged cross-sectional view of the periphery of the basket showing a state in which the extruded plate is retracted with respect to the basket in the embodiment shown in FIG.

1 to 3 show a first embodiment of a centrifuge of the present invention. The present invention is a two-stage basket type centrifuge equipped with an outer basket and an inner basket as described in Patent Document 1. FIG. This is an example applied to a separation device. That is, the centrifugal separator in the present embodiment is accommodated coaxially in a cylindrical outer basket 1 centering on a horizontal axis O having an outer filtration screen 1a attached to the body, and the outer basket 1. A cylindrical inner basket 2 having an inner filtration screen 2a attached to the body portion is provided. In the first embodiment, the inner basket 2 is a basket in the present invention. As the outer filtration screen 1a and the inner filtration screen 2a, for example, a cylindrical wire screen or a plate screen is used.

Circular open ends 1b and 2b are provided at one end (the right end in the direction of the axis O in FIGS. 1 to 3) of the cylindrical outer basket 1 and the inner basket 2 in the direction of the axis O, and the other end (FIGS. 1 to 3). (The left end in the direction of the axis O) is a bottomed cylindrical shape attached to and held by the disc- like holding plates 1c and 2c. The length of the inner basket 2 in the axis O direction is shorter than the length of the outer basket 1 in the axis O direction. The inner basket 2 is accommodated in the casing 3 and rotated integrally with the outer basket 1 around the axis O. The outer diameter of the opening end 2b of the inner basket 2 is large enough to be slidably contacted with the inner peripheral surface of the outer filtration screen 1a of the outer basket 1 by providing, for example, another annular annular plate (not shown) at the opening end 2b. It is assumed.

The holding plate 1c of the outer basket 1 is rotatably supported by a bearing 4 and attached to one end of a hollow main shaft 5 inserted into the casing 3 along the axis O. The outer basket 1 rotates around the axis O when the rotational force of a motor or the like is transmitted to a pulley (not shown) and the main shaft 5 rotates. An extrusion shaft 6 is inserted into the main shaft 5 via a key (not shown) so as to be integrally rotatable and capable of moving back and forth in the direction of the axis O. One end of the extrusion shaft 6 slidably passes through the holding plate 1c of the outer basket 1 and is attached to the holding plate 2c of the inner basket 2, so that the inner basket 2 can also rotate integrally with the outer basket 1. In addition, the other basket in the outer basket 1 can be advanced and retracted in the direction of the axis O.

Further, a plurality of support shafts 1d are provided on the holding plate 1c of the outer basket 1 so as to extend to the one end side in parallel to the axis O at a position spaced apart from the axis O toward the outer periphery in the circumferential direction. It is attached. These support shafts 1 d project through the holding plate 2 c so as to be slidable and protrude into the inner basket 2. At one end of these support shafts 1d, a disc-shaped extruded plate 7 having an outer diameter that can slide on the inner peripheral surface of the inner filtration screen 2a is attached. Therefore, the pusher plate 7 can rotate integrally around the axis O coaxially with the outer basket 1 and the inner basket 2 and can move relative to the inner basket 2 in the direction of the axis O.

In addition, an annular plate-like dispersion plate (distributor) 8 having an opening in the center is integrally supported on one end side of the extrusion plate 7 with a space from the extrusion plate 7. Further, a supply pipe 9 for the processed material is attached to the casing 3 and inserted therethrough. The supply pipe 9 passes through the opening ends 1 b and 2 b of the outer basket 1 and the inner basket 2 and is inserted into the opening of the dispersion plate 8, and the supply port of the supply pipe 9 is interposed between the extrusion plate 7 and the dispersion plate 8. It is open.

Further, a substantially U-shaped cake receiving ring 3a whose cross section along the axis O opens to the inner peripheral side is supported by the casing 3 on the outer periphery of the open end 1b of the outer basket 1 so as to surround the open end 1b. It is arranged. The cake receiving ring 3a is provided with a cake chute (not shown). After the cake discharged from the open end 1b of the outer basket 1 is received by the cake receiving ring 3a, the cake chute is inserted into the casing via the cake chute. 3 is discharged from a discharge port 3b provided below 3.

On the other hand, the other end of the extrusion shaft 6 protrudes from the other end of the main shaft 5, while allowing the rotation of the extrusion shaft 6 to the other end portion of the protruding extrusion shaft 6 via the bearing box 10, An advancing / retreating drive unit 11 is connected to move the pushing shaft 6 in the direction of the axis O together with the inner basket 2. The bearing box 10 is configured so as not to rotate with respect to the extrusion shaft 6 that rotates integrally with the main shaft 5 while rotatably supporting the other end portion of the extrusion shaft 6 by a bearing or the like (not shown). It is attached to the extrusion shaft 6 so as to be able to advance and retract.

Furthermore, the advancing / retreating drive unit 11 in this embodiment is driven by an electric motor, and in particular, the rotation of the electric motor (servo motor) 11a is arranged in the cylinder box 11b so as to extend in the direction of the axis O, such as a ball screw (not shown). Transmit to the screw shaft. A nut that is coaxially attached to a piston rod (not shown) is screwed onto the screw shaft, and the advance / retreat drive unit 11 converts the rotation of the electric motor 11a into a linear motion of the piston rod via the screw shaft and the nut. To do. Such an advancing / retreating drive unit 11 is a so-called electric cylinder, a servo cylinder, or an electric actuator.

The relative movement speed of the inner basket 2 and the pushing plate 7 in the direction of the axis O in accordance with the advance / retreat of the pushing shaft 6 by the advance / retreat driving unit 11 is set as follows. That is, the relative movement speed in the direction in which the distance D in the axis O direction between the extruded plate 7 and the opening end 2b of the inner basket 2 increases is the distance in the axis O direction between the extruded plate 7 and the opening end 2b of the inner basket 2. It is set to be smaller than the relative movement speed in the direction in which D becomes smaller. In order to set the relative movement speed in this way, control may be performed so that the relative movement speed is appropriately adjusted during operation of the centrifugal separator, and such control is performed before operation. It may be set in advance. Such control can be automatically and easily performed by inputting a program in advance to a control unit such as a computer including known components such as a CPU and a memory for controlling the electric motor 11a.

Specifically, in the present embodiment, the extrusion plate 7 is attached to the main shaft 5 via the support shaft 1d and the holding plate 1c of the outer basket 1 and fixed in the direction of the axis O, and the inner basket 2 attaches the extrusion shaft 6 to the main shaft 5. Through the direction of the axis O. Therefore, when the inner basket 2 is moved backward from the state where the inner basket 2 is retracted as shown in FIGS. 1 and 2, the open end 2b of the inner basket 2 is pushed out as shown in FIG. The distance D from the plate 7 is increased. When the relative moving speed of the outer basket 1 and the inner basket 2 in the direction in which the interval D becomes larger is caused to move the inner basket 2 backward from the state shown in FIG. Is set so as to be smaller than the moving speed in the direction in which the distance D decreases.

In one embodiment of the centrifugal separation method of the present invention using the centrifugal separator configured as described above, the processed product in which the solid liquid is turbid from the supply pipe 9 while rotating the outer basket 1 and the inner basket 2 together. (Slurry) is supplied in a constant amount per unit time. The supplied processed product hits the extrusion plate 7 and is dispersed from the space between the dispersion plate 8 and the outer peripheral side by centrifugal force, and adheres to the inner peripheral surface of the inner filtration screen 2 a of the inner basket 2. In this way, while supplying the processed material, the inner basket 2 is advanced from the state where the inner basket 2 is retracted as shown in FIGS. Then, the processed product is filtered by centrifugal force while continuously depositing in the direction of the axis O on the inner peripheral surface of the inner filtration screen 2a of the inner basket 2 that moves forward, and a cake (cake) of the processed product is formed.

Next, when the advanced inner basket 2 reaches the forward stroke end and turns backward as shown in FIG. 3, the cake of the processed material accumulated on the inner peripheral surface of the inner filtration screen 2a is moved to the retracted inner basket 2. On the other hand, they are sequentially pushed out to the one end side of the inner basket 2 by the pusher plate 7 that relatively moves forward. The cake of the processed material deposited on one end side is discharged from the open end 2b to the inner peripheral surface of the outer filtration screen 1a of the outer basket 1, and further filtered by centrifugal force while being continuously deposited in the direction of the axis O.

The cake thus deposited and filtered on the inner peripheral surface of the outer filtration screen 1a is moved to the opening end 2b of the inner basket 2 or to the opening end 2b by the next advance of the inner basket 2 that has reached the reverse stroke end. The other extruded plates (not shown) provided are sequentially pushed to one end side. Next, the cake of the processed material accumulated on one end side is discharged from the opening end 1b of the outer basket 1 to the cake receiving ring 3a, and is discharged from the discharge port 3b of the casing 3 through the chute as described above.

In this way, when the processed product is filtered by centrifuging to form a cake, the above-described centrifuging apparatus and centrifuging method have the following relative movement speed in the direction of the axis O between the inner basket 2 and the extruded plate 7. It is set like this. That is, the distance between the pushing plate 7 and the opening end 2b of the inner basket 2 is smaller than the moving speed in the backward direction of the inner basket 2 where the distance D between the pushing plate 7 and the opening end 2b of the inner basket 2 is reduced. It is set so that the moving speed in the forward direction of the inner basket 2 where the interval D in the direction of the axis O increases becomes smaller. That is, if the time of one stroke of advance and retreat is the same as that of the conventional centrifuge and the centrifugal method in which the movement speed of the forward and backward inner baskets is equal, the movement speed of the inner basket 2 of the present embodiment in the forward direction is the conventional. Smaller than that.

Therefore, when the inner basket 2 moves forward, the processed product supplied from the supply pipe 9 is in a state where the processed product is less after the processed product is pushed out by the push-out plate 7 by the backward movement of the inner basket 2. On the inner peripheral surface of the inner filtration screen 2a, a large amount of processed material is deposited more slowly over time than when the inner basket 2 moves backward. For this reason, even if the capacity | capacitance of the inner basket 2 is the same as the past, more processed products can be supplied and filtered to the inner peripheral surface of the inner filtration screen 2a in which the accumulated processed products are less likely to be filtered.

On the other hand, in the centrifuge and the centrifuge method having the above-described configuration, the inner basket 2 is moved backward so that the inner filtration screen 2a can move within the inner filtration screen 2a as compared with the conventional case in which the time of one stroke is the same and the moving speeds of the forward movement and the backward movement are equal. The moving speed of the inner basket 2 when the processed material accumulated on the peripheral surface is pushed out by the extrusion plate 7 is increased. For this reason, the amount of the processed material further added on the processed material deposited on the inner peripheral surface of the inner filtration screen 2a immediately on the one end side of the extruded plate 7 in the direction of the axis O can be reduced. Therefore, it is possible to suppress the supply amount of the processed material to the inner filtration screen 2a in a state where the processed material is deposited and hardly filtered.

Therefore, according to the centrifugal separator and the centrifugal method thus configured, the capacity of the inner basket 2 (basket) is increased to increase the size of the centrifugal separator, or the inner basket 2 can be moved relative to the extruded plate 7. It is not necessary to lengthen the time of one stroke of advance / retreat by a typical movement. By increasing the supply amount of the processed material to the inner filtration screen 2a that is easily filtered, more processed products can be reliably and efficiently processed in one stroke. Furthermore, it is possible to form a uniform cake over the entire length of the inner basket 2 by suppressing the supply of the processed material to the inner filtration screen 2a that is difficult to be filtered. Therefore, it is possible to reduce the apparatus cost and installation space of the centrifugal separator, simplify the installation foundation by reducing the weight of the apparatus, and perform post-treatment of the filtered cake stably and easily.

In the present embodiment, in order to set the moving speed of the inner basket 2 with respect to the pushing plate 7 as described above, an electric motor 11a is used as the advancing / retreating drive unit 11 for moving the inner basket 2 back and forth via the pushing shaft 6. Yes. However, even when the extrusion shaft 6 and the inner basket 2 are advanced and retracted by hydraulic drive as in the prior art, there is a difference in the flow diameter of the hydraulic oil at the time of forward movement and backward movement, a speed controller is installed, or a cylinder It is possible to set the movement speed by providing a difference in the discharge speed of the hydraulic oil by bypassing the discharge side flow path. However, in this case, there is a problem that the hydraulic pressure becomes unstable when the forward / backward movement is switched, and it may be difficult to reliably set the predetermined relative movement speed.

On the other hand, the advancing / retreating drive unit 11 using the electric motor 11a as in the present embodiment has high responsiveness, and can change the moving direction quickly even when the advancing / retreating is switched. Furthermore, it becomes possible to set the moving speed reliably and stably, especially when the relative moving speed of the inner basket 2 with respect to the push-out plate 7 is set to a different magnitude as in the centrifugal separator and the centrifugal method having the above-described configuration. Is preferred.

As the advancing / retreating drive unit 11 using such an electric motor 11a, an electric cylinder that converts the rotation of the electric motor 11a into a linear motion of a piston rod by a screw shaft and a nut as in the above embodiment can be used. . In addition, it is possible to use a linear cylinder in which the piston rod is linearly moved directly by an electric linear motor. In addition, using a so-called fastener-type actuator, etc., that two or more chains are engaged with each other and are moved forward by an electric motor in a columnar shape, and are pulled back and retracted while being disengaged from the chain. Is also possible.

Next, FIG. 4 and FIG. 5 show a second embodiment of the centrifuge of the present invention. Portions common to the centrifuge of the first embodiment are assigned the same reference numerals and description thereof is omitted.
In the centrifuge of the second embodiment shown in FIGS. 4 and 5, the other end portion in the direction of the axis O (not shown) is the same as that of the centrifuge of the first embodiment, so that the illustration is omitted.

In the first embodiment, the inner basket 2 is accommodated in the outer basket 1 so as to be integrally rotatable, and the inner basket 2 is attached to the extrusion shaft 6 and is advanced and retracted in the direction of the axis O. The extruding plate 7 supported thereby is held at a fixed position in the direction of the axis O, so that the extruding plate 7 can move relative to the basket (inner basket 2) in the direction of the axis O. In the second embodiment, a single basket 21 having a filtering screen 21a at the body and having an open end 21b at one end in the direction of the axis O is attached to one end of the main shaft 5 via a holding plate 21c. . A basket 21 is held at a fixed position in the direction of the axis O, and an outer diameter push plate 22 slidably contacting the inner peripheral surface of the filter screen 21a is coaxially connected to one end of the push shaft 6 inserted through the holding plate 21c. It moves forward and backward in the direction of the axis O. Thereby, the extrusion plate 22 is movable relative to the basket 21 in the direction of the axis O.

Therefore, in the second embodiment, the basket 21 and the open end 21b of the basket are movable at a fixed position in the direction of the axis O, and the pusher plate 22 is moved back and forth in the direction of the axis O. Therefore, the direction in which the distance in the axis O direction between the extrusion plate 22 and the open end 21b of the basket 21 increases is the direction when the extrusion plate 22 moves backward, and the direction in which the interval decreases decreases when the extrusion plate 22 moves forward. Direction.

And also in this embodiment, the relative moving speed of the extrusion plate 22 and the basket 21 in the direction of the axis O is set as follows. That is, from the state where the extrusion plate 22 shown in FIG. 4 moves forward with respect to the basket 21 and the distance D in the axis O direction between the extrusion plate 22 and the open end 21b of the basket 21 is small, the extrusion plate 22 and basket shown in FIG. The relative movement speed in the direction in which the distance D in the axis O direction with respect to the opening end 21b of 21 is increased, that is, the direction in which the extrusion plate 22 is retracted, is The distance D is set to be smaller than the relative movement speed in the direction in which the distance D shown in FIG.

For this reason, also in this embodiment, when the extruded plate 22 moves backward after extruding the processed material deposited on the inner peripheral surface of the filtration screen 21a, the amount of accumulation after the processed material is extruded is less likely to be filtered. On the inner peripheral surface of the filter screen 21a, a new processed material supplied from the supply pipe 9 is slowly accumulated over time. Therefore, a large amount of processed material can be efficiently filtered. On the other hand, when the extruded plate 22 is pushed out and the distance D from the opening end 21b becomes small when the accumulated processed material is pushed out, the moving speed is large, and the amount of the processed material added on the already deposited processed material is reduced. be able to. Therefore, a uniform cake can be formed over the entire length of the basket 21.

Note that, as in the first and second embodiments, the relative movement speed in the direction of the axis O with respect to the baskets 2 and 21 of the extrusion plates 7 and 22 is the relative movement speed in the direction in which the interval D in the direction of the axis O increases. However, when the ratio is set to be smaller than the relative movement speed in the direction in which the interval D is reduced, if the ratio is too large, it is difficult to set the movement speed of the moving basket (inner basket 2) and the extrusion plate 22. become. For this reason, there is a possibility that a large amount of processed material cannot be reliably supplied to the filtering screens 2a and 21a that are easily filtered, or a large amount of processed material is added to the filtering screens 2a and 21a that are difficult to be filtered.

Therefore, the relative movement speed in the direction in which the distance D in the axis O direction between the extrusion plates 7 and 22 and the open ends 2b and 21b of the baskets 2 and 21 increases is the relative movement speed in the direction in which the distance D decreases. It is desirable to set so as to decrease at a speed of 1/4 or higher. However, even if the difference between these relative movement speeds is small, there is a possibility that the above-described action cannot be effectively achieved. For this reason, it is more desirable that the relative movement speed in the direction in which the distance D increases is set to 2/3 or less of the relative movement speed in the direction in which the distance D decreases. In the first embodiment, the present invention is applied to a centrifuge having a two-stage basket of an outer basket 1 and an inner basket 2, and a centrifuge having a single basket 21 and a centrifuge method in the second embodiment. The case of applying was explained. However, it is of course possible to apply the present invention to a centrifugal separator and a centrifugal method having three or more baskets.

According to the centrifugal separator and the centrifugal method of the present invention, it is possible to efficiently filter the processed material without enlarging the basket capacity to increase the size or lengthening the time for one stroke of advancement / retraction. While increasing the amount of processing, a uniform cake can be formed. Therefore, it is possible to reduce the cost of the centrifuge device itself, reduce the installation space of the device, simplify the installation base by reducing the weight of the device, and stably and easily perform post-processing of the cake. It becomes possible.

DESCRIPTION OF SYMBOLS 1 Outer basket 1a Outer filtration screen 1b Open end of outer basket 1 2 Inner basket (basket)
2a Inner filtration screen 2b Open end of inner basket 2 3 Casing 5 Main shaft 6 Extrusion shaft 7, 22 Extrusion plate 8 Dispersion plate 9 Processed product supply pipe 10 Bearing box 11 Advance / retreat drive unit 11a Electric motor 11b Cylinder box 21 Basket 21a Filtration screen 21b Open end of basket 21 O Axis of rotation of basket 21 (outer basket 1, inner basket 2) D Distance between push plates 7, 22 and inner basket 2, open ends 2b, 21b of basket 21 in the direction of axis O

Claims (6)

1. A cylindrical basket provided with a filtration screen on the body and rotated about an axis, and accommodated in the basket and rotatable integrally with the basket and movable relative to the basket in the axial direction. A centrifuge that extrudes and discharges the cake filtered by the filter screen from the processed product supplied into the basket to the opening end side of the basket by the extrusion plate,
   The relative movement speed in the axial direction between the extrusion plate and the basket is such that the relative movement speed in the direction in which the axial distance between the extrusion plate and the open end of the basket increases becomes larger. The centrifugal separator is set to be smaller than a relative moving speed in a direction in which the distance in the axial direction from the opening end of the shaft becomes smaller.
2. The relative movement speed in the direction in which the axial distance between the extrusion plate and the open end of the basket is increased is relative to the direction in which the axial distance between the extrusion plate and the open end of the basket is reduced. The centrifugal separator according to claim 1, wherein the centrifugal separator is set to ¼ or more of the moving speed.
3. The relative movement speed in the direction in which the axial distance between the extrusion plate and the open end of the basket is increased is relative to the direction in which the axial distance between the extrusion plate and the open end of the basket is reduced. The centrifuge according to claim 1 or 2, which is set to 2/3 or less of the moving speed.
4. A processed product is supplied into a cylindrical basket provided with a filter screen on the body and rotated about its axis, and the cake filtered by the filter screen from the processed product is accommodated in the basket and integrated. A centrifugal separation method for extruding and discharging to the opening end side of the basket by an extrusion plate that is rotatable and movable relative to the basket in the axial direction,
   The relative movement speed in the axial direction between the extrusion plate and the basket is the relative movement speed in the direction in which the axial distance between the extrusion plate and the open end of the basket is large. The centrifugal separation method is set so as to be smaller than the relative moving speed in the direction in which the distance between the opening end of the shaft and the axial direction decreases.
5. The relative movement speed in the direction in which the axial distance between the extrusion plate and the open end of the basket is increased is relative to the direction in which the axial distance between the extrusion plate and the open end of the basket is small. The centrifugation method according to claim 4, wherein the centrifugal speed is set to 1/4 or more of the moving speed.
6. The relative movement speed in the direction in which the axial distance between the extrusion plate and the open end of the basket is increased is relative to the direction in which the axial distance between the extrusion plate and the open end of the basket is small. The centrifugation method according to claim 4 or 5, wherein the centrifugal speed is set to 2/3 or less of the moving speed.

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