JP7161199B2 - centrifuge - Google Patents

Description

TECHNICAL FIELD The present invention relates to a centrifugal separator that performs a solid-liquid separation process in which an undiluted liquid is separated into a liquid component and a cake component (solid component) by centrifugal sedimentation.

As a centrifugal separator for solid-liquid separation, a stock solution is supplied into a basket rotating at high speed, and a filter arranged on the inner circumference of the peripheral wall of the basket and a large number of through holes provided on the peripheral wall of the basket are used. Filtration-type centrifugal separators are widely used, which separate the undiluted liquid into a liquid component and a cake component by discharging the liquid component from the basket through a filter.

In the filtration-type centrifugal separator, the liquid supply step of supplying the undiluted solution into the rotating basket and the liquid removal step of discharging the liquid content out of the basket by the centrifugal force generated by the rotation of the basket are repeated. Since a cake layer is formed on the inner circumference of the peripheral wall of the basket, it is essential that the liquid is removed through the cake layer. Therefore, when the crystals contained in the stock solution are not so fine, the structure of the cake layer is rough, and the liquid permeates well, many crystals can be obtained in one solid-liquid separation treatment, When the crystals contained in the stock solution are fine and the cake layer has a dense structure, when the cake layer becomes thick to some extent, it becomes impossible to remove the liquid through the cake layer. The amount of cake is limited, and the solid-liquid separation process cannot be performed efficiently.

As a centrifugal separation device that can perform solid-liquid separation even if the crystals contained in the stock solution are dense, a basket without permeation holes in the peripheral wall is used to separate the stock solution into a liquid portion and a cake portion by centrifugal sedimentation. A basket-type centrifugal separator is known that separates into In this type of centrifugal separator (also called centrifugal sedimentation separator), a stock solution is supplied into a basket rotating at high speed, and the cake portion, which has a higher specific gravity than the liquid portion, is separated from the peripheral wall side of the basket by centrifugal force. to form a cake layer inside the peripheral wall of the basket, and a supernatant liquid layer is formed inside the cake layer. After the basket is rotated at high speed for a predetermined time to sufficiently separate the cake layer and the supernatant liquid layer, the supernatant liquid existing in the basket is discharged out of the basket, and then the cake layer formed in the basket is removed. is discharged to the outside.

In a conventional centrifugal sedimentation apparatus, for example, as shown in Patent Document 1, the supernatant liquid is discharged from the basket by inserting a skimming pipe into the supernatant liquid layer from the opening of the basket rotating at high speed. It was done by doing.

A decanter-type centrifugal sedimentation apparatus as disclosed in Patent Document 2 is also known. This separation device comprises a separation cylinder that is rotated at high speed, and a screw conveyor that is arranged inside the separation cylinder and is rotated at a speed slower than the separation cylinder. The supplied stock solution is separated into a solid content and a liquid content by centrifugal sedimentation, and the liquid content is discharged to the outside from a liquid outlet formed at the rear end of the separation cylinder. The solid content is moved to the front end side of the separation cylinder by the screw conveyor and discharged to the outside from the solid content discharge port at the tip of the separation cylinder.

In the basket-type centrifugal separator, regardless of whether it is of a filtration type or a centrifugal sedimentation type, how to efficiently discharge and collect the cake formed in the basket outside the basket is important. becomes a problem. As a filtration type centrifugal separator aiming at efficiently collecting the cake formed in the basket, as shown in Patent Document 3, a filter cloth is interposed between the peripheral wall portion of the basket and the cake layer. 2. Description of the Related Art There is known a filter cloth inversion type centrifugal separator in which almost the entire amount of cake formed in a basket can be discharged out of the basket by inverting the filter cloth. In this centrifugal separator, the solid-liquid separation process is performed with the opening of the basket closed with a lid. cannot be discharged. Therefore, it is not possible to perform solid-liquid separation using the centrifugal sedimentation action using a conventional filter cloth inversion type centrifugal separator. A centrifugal separator with a filter cloth inversion type cannot be used.

JP-A-57-117356 JP-A-60-25562 JP-A-1-249146

Recently, there is an increasing need to perform a solid-liquid separation treatment of a stock solution containing fine crystal particles. As described above, a centrifugal sedimentation device is known as a centrifugal device for solid-liquid separation of a stock solution containing fine crystals. When a skimming pipe is inserted into the supernatant liquid layer through the opening of the basket rotating at high speed in order to discharge the supernatant liquid, waves are generated in the supernatant liquid layer and a large impact is applied to the basket. Problems have arisen such that the vibration becomes large, making it difficult to continue the operation, and the separated cake portion dissolves into the supernatant, making the supernatant turbid.

In addition, in the conventional centrifugal sedimentation device, after discharging the supernatant liquid from the basket, the work of collecting the cake from the basket was done manually, so the cake could not be collected efficiently. .

As described above, a centrifugal separator with a filter cloth inversion type is known as a centrifugal separator capable of efficiently collecting the cake from the basket. Since the apparatus did not have means for discharging the supernatant formed in the basket, it could not be used for the purpose of solid-liquid separation using centrifugal sedimentation.

According to the decanter-type centrifugal sedimentation device as shown in Patent Document 2, the separation of liquid and cake can be continuously performed. This type of centrifugal separator cannot be used for the purpose of obtaining a cake consisting of fine crystals containing no liquid, since the liquid cannot be sufficiently separated from the liquid.

The object of the present invention is to perform centrifugal sedimentation without causing problems such as the vibration of the basket becoming large and making it difficult to continue the operation, or the separated cake portion eluting into the supernatant liquid and making the supernatant liquid cloudy. In addition to being able to perform solid-liquid separation processing using centrifugal sedimentation, it is possible to easily collect the supernatant liquid from the basket and the cake. An object of the present invention is to provide a centrifugal separator capable of smoothly and efficiently.

According to the present invention, a basket having a peripheral wall, one axial end of which is closed by a bottom wall, and an opening provided on the other axial end of the basket is rotated to centrifuge the undiluted solution supplied into the basket. The object is a centrifugal separator that separates liquid and cake by sedimentation.

The centrifugal separation device according to the present invention is provided so as to rotate together with the basket with one surface and the other surface facing the bottom wall side of the basket and the side opposite to the bottom wall portion, respectively, and the one surface is inside the basket. Along the axial direction of the basket between the retracted position set to face the bottom wall of the basket with a gap and the forward position set to the opening of the basket or in front of the opening a displaceable cake push-out plate that air-tightly closes the opening of the basket when the cake push-out plate is in the retracted position and closes the opening of the basket while the cake push-out plate is displaced toward the advanced position; A cover plate that opens the part and is attached to the cake push-out plate in a state that a part penetrates the cake push-out plate, and penetrates the cake push-out plate from the other side of the cake push-out plate to the one side of the cake push-out plate. and a drainage hole penetrating the basket at a position facing a gap between one surface of the cake push-out plate and the bottom wall of the basket. When the opening of the basket is closed by the cover plate in the retracted position, the air pressure in the basket is increased to a set pressure higher than the outside air pressure, and the supernatant liquid existing in the basket is discharged into the drainage device. The cake in the basket is discharged to the outside of the basket through the channel and the drainage hole, and the cake push-out plate is displaced from the retracted position to the advanced position to push the cake out of the basket. configured to

With the above construction, the supernatant liquid is discharged to the outside while the drainage device rotates at the same speed as the basket. can be discharged out of the basket. After the discharge of the supernatant liquid is completed, the cake can be discharged from the basket by pushing the cake out of the basket with the cake push-out plate, so that the cake can be easily recovered from the basket.

In order to facilitate the discharge of the liquid discharged between the cake push-out plate and the bottom wall of the basket to the outside of the basket, the liquid drain hole penetrates the portion of the peripheral wall of the basket near the bottom wall. It is preferable to provide it in a

In a preferred embodiment of the present invention, the advancing position of the cake push-out plate is set in front of the opening of the basket, the plate is made of a flexible material in a cylindrical shape, one end of which is fixed to the opening of the basket, and the cake push-out plate is positioned forwardly. The other end is fixed to the outer peripheral part of the plate, and when the cake push-out plate is in the retracted position, it is arranged in a state of covering the inner circumference of the peripheral wall part of the basket, and the cake push-out plate is displaced from the retracted position toward the advanced position. A flexible sleeve is provided which is inverted in the process.

The flexible sleeve is similar to the filter cloth used in conventional filter cloth inverting centrifugal separators in that it can be turned over to facilitate the discharge of the cake from the basket. However, the flexible sleeve is different from the filter cloth used in the conventional filter cloth reversing centrifugal separator in that it does not need to have a function as a filter.

When the flexible sleeve is provided in this way, when collecting the cake from the basket, the cake push-out plate is rotated together with the basket and displaced from the retracted position to the advanced position, so that the cake push-out plate pushes the cake out of the basket. is pushed out, and the flexible sleeve is reversed as the cake push-out plate advances, and the cake adhering to the flexible sleeve can be dropped off by centrifugal force, so that all the cake in the basket is pushed out of the basket. can be discharged to a high recovery rate of the cake.

In another preferred aspect of the present invention, the drainage device has a portion penetrating the cake push-out plate along the axial direction of the basket at a position eccentric from the rotation center axis of the basket. A push-plate penetration part having a flow path inside that penetrates the cake push-out plate from the side and flows a liquid to one side of the cake push-out plate, and a push-plate penetration part arranged on the other side of the cake push-out plate The flow path is connected at the ends and is provided with the front end directed toward the peripheral wall of the basket, the front end opening toward the peripheral wall of the basket, and the rear end communicating with the flow path in the pusher plate penetration part. inside the cake push-out plate and the bottom wall of the basket on the other end side of the push-out plate through-hole arranged on the one side of the cake push-out plate. An opening is provided that opens into the gap between the part.

In this case, the liquid introduction portion of the drainage device includes a movable portion that is displaced toward the outer diameter side of the basket by the centrifugal force generated as the basket rotates, and biasing means that biases the movable portion toward the inner diameter side of the basket. and Also, when the air pressure in the basket is below the set pressure, the liquid in the basket is prevented from flowing out into the gap through the channel in the drainage device, and when the air pressure in the basket exceeds the set pressure, the The drainage device is provided with a check valve that allows the liquid in the basket to flow out into the gap through the channel in the drainage device.

After performing the solid-liquid separation process for separating the undiluted solution supplied into the basket into a liquid portion and a cake portion by configuring the drainage device as described above, the movable portion of the drainage device is moved into the supernatant liquid in the basket. When the basket is open, high-pressure gas is supplied into the basket to make the pressure in the basket higher than the set pressure, which is higher than the outside air pressure. Since the flow is allowed, the supernatant liquid present in the basket can be discharged into the gap between the cake pushing plate and the bottom wall of the basket through the channel in the drainage device, and this gap The liquid discharged inside can be discharged to the outside of the basket through the liquid discharge hole. By accelerating the basket, the movable part of the drainage device can finally be displaced to a position in contact with the cake layer, so that almost all of the supernatant liquid in the basket can be discharged out of the basket.

Other aspects of the invention will become apparent from the description of the embodiments of the invention that follows.

According to the present invention, the retracted position is set to face the bottom wall of the basket with a gap in the basket, and the forward position is set to the opening of the basket or in front of the opening. A supernatant liquid is formed in the basket by attaching a drainage device to the cake push-out plate which is provided so as to be displaceable along the axial direction of the basket and rotates with the basket, and pressurizes the inside of the basket. is discharged out of the basket through the flow path in the drainage device that rotates with the basket, the gap between the cake pushing plate and the bottom wall of the basket, and the drainage hole provided in the basket. The supernatant liquid can be discharged smoothly without giving any shock to the basket and without making the supernatant liquid rippling. Further, the cake can be discharged out of the basket by pushing the cake out of the basket by the cake push-out plate, so that the cake can be easily collected.

Further, in the present invention, the advancing position of the cake push-out plate is set in front of the opening of the basket, one end of a flexible sleeve formed in a tubular shape from a flexible material is fixed to the opening of the basket, When the other end of the flexible sleeve is fixed to the outer peripheral portion of the cake push-out plate, the cake push-out plate is displaced from the retracted position to the advanced position, and the cake in the basket is pushed out by the cake push-out plate. By inverting the flexible sleeve, all the cakes in the basket can be discharged to the outside of the basket, so that the cake recovery rate can be increased.

FIG. 1 is a vertical cross-sectional view showing a state in which a cake pushing plate is arranged at a retracted position in an embodiment of the present invention. FIG. 2 is a vertical cross-sectional view showing the configuration of the main parts in a state in which the cake pushing plate is displaced to the forward position in the embodiment of the present invention. FIG. 3 is an enlarged view of part A in FIG. FIG. 4 is an enlarged view of the B portion of FIG.

An embodiment of the present invention will be described in detail below with reference to the drawings. Referring to FIG. 1, the overall configuration of the device is shown in this embodiment with the cake pusher plate in the retracted position, and FIG. 2 shows the cake pusher plate in the advanced position. , the configuration of the essential parts of the device is shown. 1 and 2, reference numeral 1 denotes a cylindrical shape having a peripheral wall portion 101, a bottom wall portion 102 closing one axial end of the peripheral wall portion, and an opening 103 formed at the other axial end of the peripheral wall portion 101. is a basket. The basket 1 is arranged with the central axis of the peripheral wall 101 oriented horizontally, and is driven to rotate about the central axis of the peripheral wall 101 by a rotation drive mechanism, which will be described later.

In order to facilitate the discharge of the cake from the basket 1, the peripheral wall portion 101 of the basket 1 is tapered such that the inner diameter gradually increases from the bottom wall portion 102 side of the basket toward the opening portion 103 side. The inner diameter of the basket 1 gradually increases from the bottom wall portion 102 side toward the opening portion 103 side of the basket.

In FIGS. 1 and 2, 2 is a disk-shaped cake pushing plate that rotates together with the basket 1 and is displaced in the axial direction of the basket 1 . In this embodiment, one and the other of both main surfaces of the cake push-out plate 2 are defined as one surface 2a and the other surface 2b (see FIG. 4) of the cake push-out plate.

The cake push-out plate 2 has its one surface 2a and the other surface 2b facing the bottom wall 102 side of the basket 1 and the side opposite to the bottom wall 102, respectively, and has its center axis of rotation aligned with the center axis of rotation of the basket 1. and one surface 2a thereof faces the bottom wall portion 102 of the basket 1 in the basket 1 with a gap d therebetween. It can be linearly displaced along the axial direction of the basket 1 between a position (the position shown in FIGS. 1 and 4) and an advanced position (the position shown in FIG. 2) set in front of the opening 103 of the basket 1. is provided as follows. The outer diameter of the cake push-out plate 2 is set slightly smaller than the inner diameter of the peripheral wall portion 101 of the basket facing the outer circumference of the cake push-out plate 2 in the retracted position. The cake push-out plate 2 is driven by a linear drive mechanism to be described later so as to linearly reciprocate between a retracted position and an advanced position.

The space in the basket 1 is formed in the basket 1 by the part forming the gap d between the cake push-out plate 2 and the bottom wall portion 102 of the basket 1 when the cake push-out plate 2 is in the retracted position. A drainage chamber A1 for discharging the supernatant liquid is configured. Further, when the cake pushing plate 2 is in the retracted position, the space in the basket 1 which is located closer to the opening 103 than the cake pushing plate 2 constitutes a solid-liquid separation processing chamber A2. A solid-liquid separation process is performed in this processing chamber A2.

3 closes the opening 103 of the basket 1 when the cake push-out plate 2 is in the retracted position, and opens the opening 103 of the basket 1 in the process of displacing the cake push-out plate 2 toward the forward position. It is the cover plate of In this embodiment, when the supernatant liquid formed in the basket 1 is discharged, the lid plate 3 closes the opening of the basket 1 airtightly so that the pressure inside the basket 1 is higher than the outside pressure. is configured to allow

The illustrated lid plate 3 is connected to the cake push-out plate 2 by a plurality of connecting rods 4 extending in the axial direction of the basket 1 and arranged at equal angular intervals in the circumferential direction of the basket 1. When the cake pushing plate 2 is in the retracted position, the opening 103 of the basket 1 is airtightly closed at the closed position (the position shown in FIG. 1), and the cake pushing position 2 reaches the advanced position. Sometimes it is arranged in a retracted position (the position shown in FIG. 2) set in front of the opening of the basket 1 .

Sealing means such as packing is attached to a portion near the outer periphery of the lid plate 3, and the sealing means is interposed between the lid plate 3 and the opening 103 of the basket 1 when the lid plate 3 is in the closed position. As a result, the abutting portion between the opening 103 of the basket and the cover plate 3 is kept airtight. The cover plate 3 is linearly displaced together with the cake push-out plate 2 when the cake push-out plate 2 is driven by a linear drive mechanism to be described later.

In the centrifugal separator according to the present invention, when solid-liquid separation is performed, the stock solution supply means for supplying the stock solution into the basket 1, and when the supernatant is discharged from the basket 1, the external pressure (usually atmospheric pressure) It is necessary to provide a high pressure gas supply means for supplying a high pressure gas of a higher pressure into the basket 1 . In order to constitute these means, a feed pipe introduction portion 5 is formed in the central portion of the cover plate 3, and a feed pipe 6 is introduced into the basket 1 through this introduction portion. The feed pipe 6 is selectively connected to at least the raw liquid supply source and the high-pressure gas supply source, and the feed pipe 6 and the raw liquid supply source form a raw liquid supply means for supplying the raw liquid into the basket 1. Configured. The feed pipe 6 and the high-pressure gas supply source constitute high-pressure gas supply means for supplying high-pressure gas into the basket 1 . A sealing member is provided between the feed pipe 6 and the feed pipe introducing portion 5 to keep the feed pipe 6 passing through air-tight and liquid-tight. In this embodiment, the feed pipe 6 is provided so as to rotate together with the basket 1 in order to facilitate airtightness and liquidtightness of the portion where the feed pipe 6 penetrates the cover plate 3 .

Referring to FIG. 3, the feed pipe introduction portion 5 provided in the central portion of the cover plate 3 and the portion near the tip of the feed pipe 6 introduced into the basket through this introduction portion are illustrated. The feed pipe introduction portion 5 has a through hole 501 provided through the central portion of the cover plate 3, a tubular portion 502a penetrating through the through hole 501, and a flange portion 502b formed at one end of the tubular portion 502a. Pipe receiving member 502, seal member 503 held inside tubular portion 502a of pipe receiving member 502, washer 505 in contact with flange portion 502b of pipe receiving member 502, washer 505 and flange portion 502b. The feed pipe 6 is introduced into the basket while passing through the seal member 503 .

The seal member 503 is a member for maintaining air-tightness and liquid-tightness of the feed pipe 6 penetration portion while allowing relative linear movement to occur between the feed pipe 6 and the cover plate 3. As a member, for example, a piston packing used to seal the sliding portion between the cylinder and the piston in a general-purpose air cylinder, or used to seal the sliding portion between the piston rod and the cylinder. Similar to rod packing can be used. Since the feed pipe 6 and the seal member 503 are tightly fitted together, when the cover plate 3 rotates together with the basket 1 and the cake push-out plate 2, the feed pipe 6 also rotates following the rotation.

As shown in FIGS. 1, 2 and 4, a plurality of drainage holes h are formed at intervals in the circumferential direction of the basket 1 in a portion of the peripheral wall portion 101 of the basket 1 near the bottom wall portion 102. It is installed in the The drainage hole h is provided in a state of penetrating a portion of the peripheral wall portion 101 of the basket facing the gap d (drainage chamber A1) between the cake push-out plate 2 and the bottom wall portion 102, and is used for solid-liquid separation. It is used to discharge the supernatant discharged into the drainage chamber A1 from the processing chamber A2 through a drainage device, which will be described later, to the outside of the basket.

Among the parts of the peripheral wall of the basket 1, the part facing the space in the basket (solid-liquid separation processing chamber A2) formed between the cake pushing plate 2 in the retracted position and the opening 103 of the basket is filled with liquid. There are no holes through which liquids can pass, and the undiluted liquid is supplied into the solid-liquid separation processing chamber A2 in the basket 1 with the cake push-out plate 2 positioned at the retracted position to perform the solid-liquid separation processing. Filtration (drainage) is not performed through the peripheral wall of the basket.

The feed pipe 6 is supported via a rotary joint in front of the opening of the basket 1 by a member forming a cake collection chamber. The support structure for the members forming the cake collection chamber in front of the opening of the basket 1 and the feed pipe 6 will be described later.

In this embodiment, in order to facilitate the discharge of the layered cake formed in the solid-liquid separation processing chamber A2 in the basket 1, a flexible material such as cloth is used to form a tubular cake. A flexible sleeve 7 is provided. One end of the flexible sleeve 7 is arranged along the inner periphery of the opening 103 of the basket 1 and fixed to the opening 103 of the basket by appropriate means, and the other end of the flexible sleeve 7 is a cake. It is arranged along the outer circumference of the push-out plate 2 and fixed to the outer circumference of the cake push-out plate by an appropriate means. The flexible sleeve 7 is arranged to cover the inner periphery of the peripheral wall portion 101 of the basket 1 when the cake push-out plate 2 is in the retracted position, and the cake push-out plate 2 moves from the retracted position to the advanced position. can be reversed with . As shown in FIG. 2, the flexible sleeve 7 is completely reversed when the cake push-out plate 2 reaches the forward position and stretched between the cake push-out plate 2 and the opening of the basket 1. become.

In this embodiment, a cylindrical lining sheet 8 (see FIG. 4) is arranged along the inner circumference of the peripheral wall portion 101 of the basket 1, and when the cake push-out plate 2 is in the retracted position, the flexible The sleeve 7 covers the inner periphery of the peripheral wall portion 101 of the basket with the sheet 8 interposed therebetween. Note that the sheet 8 can be omitted.

In this embodiment, since the portion of the peripheral wall portion 101 of the basket 1 that constitutes the solid-liquid separation processing chamber A2 is not provided with a through-hole that allows the liquid to pass therethrough, the solid-liquid separation processing is not a filtration action but a centrifugal action. It is carried out by a sedimentation action. In the solid-liquid separation process by centrifugal sedimentation, among the components contained in the undiluted solution, the cake portion having a large specific gravity is sedimented and deposited in a region closer to the peripheral wall portion 101 of the basket by centrifugal force to form a cake layer on the inner periphery of the peripheral wall portion of the basket. C (see FIG. 4) is formed, and inside this cake layer C, a liquid layer with a small specific gravity is formed as a supernatant liquid layer W (see FIG. 4).

When the stock solution is started to be supplied into the basket 1, the liquid is discharged from the solid-liquid separation processing chamber A2 through the gap between the outer peripheral portion of the cake pushing plate 2 in the retracted position and the inner peripheral portion of the peripheral wall portion 101 of the basket. In order to prevent the stock solution from penetrating into the chamber A1 side, when the cake pushing plate 2 is in the retracted position, the liquid moves between the outer peripheral surface of the cake pushing plate 2 and the inner peripheral surface of the peripheral wall portion 101 of the basket. It is preferable to take measures to prevent the formation of gaps that allow A packing may be attached to the outer peripheral portion of the cake push-out plate 2, but in this embodiment, the end of the flexible sleeve 7 on the cake push-out plate 2 side is pushed out of the cake push-out plate 2 when the cake push-out plate 2 is in the retracted position. By interposing between the outer peripheral portion of the plate 2 and the inner peripheral portion of the peripheral wall portion 101 of the basket 1 to close the gap between the cake push-out plate 2 in the retracted position and the peripheral wall portion 101 of the basket, solid-liquid This prevents liquid from moving from the solid-liquid separation processing chamber A2 side to the drainage chamber A1 side at the start of separation processing.

Even if there is a small gap between the outer circumference of the cake push-out plate at the retracted position and the inner circumference of the basket's peripheral wall 101, the solid-liquid separation process progresses and the cake layer is formed inside the peripheral wall of the basket 1. is formed, the cake layer closes the gap between the outer peripheral portion of the cake pushing plate 2 and the inner peripheral portion of the peripheral wall portion 101 of the basket 1, so that the liquid is discharged from the solid-liquid separation processing chamber A2. Movement of the liquid to the chamber A1 side is blocked. Therefore, in the present invention, it is not essential to provide means for closing the gap between the outer peripheral portion of the cake push-out plate 2 and the inner peripheral portion of the peripheral wall portion 101 of the basket 1 .

When discharging (recovering) the cake layer formed in the basket 1 to the outside, the cake push-out plate 2 is displaced toward the forward position to remove the cake layer C formed in the solid-liquid separation processing chamber A2. is pushed by the cake push-out plate 2 to be pushed out from the opening 103 of the basket 1 and dropped into the cake collection chamber prepared in front of the opening of the basket. In the process of displacing the cake push-out plate 2 to the forward position through the opening of the basket 1, the flexible sleeve 7 is reversed to drop the cake adhering to the flexible sleeve 7 into the cake collection chamber. The flexible sleeve 7 is completely reversed as shown in FIG. 2 when the cake pushing plate 2 reaches the advanced position. Since the flexible sleeve 7 rotates together with the basket, it is adhered to the flexible sleeve 7 by rotating the basket for a certain period of time while the flexible sleeve 7 is completely inverted as shown in FIG. The resulting cake can be dropped from the flexible sleeve 7 by centrifugal force and almost completely recovered.

After collecting the cake produced in the basket as described above, the cake pushing plate 2 is displaced toward the retracted position. When the cake push-out plate 2 is displaced toward the retracted position, the flexible sleeve 7 is returned to the non-inverted state as the cake push-out plate 2 is displaced, and when the cake push-out plate 2 reaches the retracted position, the basket is retracted. is returned to a state in which the inner periphery of the peripheral wall portion of is covered.

After the cake layer C and the supernatant liquid layer W are formed in the solid-liquid separation processing chamber A2, before discharging and recovering the cake layer from the basket, the supernatant liquid existing in the basket sealed by the cover plate 3 is removed. must be discharged outside the basket. In this embodiment, in order to allow the supernatant liquid to be discharged from the sealed basket, the cake pushing plate 2 is provided with a plurality of drainage devices 9 in an area closer to the outer circumference than the central part of the cake pushing plate 2. is positioned and installed. In order not to disturb the weight balance of the basket, it is preferable to attach a plurality of drainage devices 9 in a state that they are arranged at equal angular intervals in the circumferential direction of the peripheral wall portion 101 of the basket 1 . If the weight balance of the basket is disturbed by attaching the drainage device 9 to the cake pushing plate 2, it is preferable to balance the weight of the basket by attaching a balance weight to the basket.

The drainage device 9 used in the present embodiment is fixed to the cake push-out plate 2 in a state that a part of it penetrates the cake push-out plate 2, and from the other surface 2b side of the cake push-out plate 2 (the solid-liquid separation processing chamber A2 side ), a flow path is formed in the interior thereof for flowing a liquid toward the one surface 2a side (drain chamber A1 side).

As shown in FIG. 4, the drainage device 9 used in this embodiment has a portion that penetrates the cake push-out plate 2 along the axial direction of the basket 1 at a position eccentric from the axis of rotation of the basket 1 . and a cake push-out plate 2, a push-out plate penetrating portion 9A having therein a flow path through which liquid flows from the other surface 2b side of the cake push-out plate 2 to the one side 2a side of the cake push-out plate 2; A rear end portion is connected to one end of the pushing plate through portion 9A arranged on the other side, and a liquid introduction portion 9B is provided with the tip portion facing the peripheral wall portion 101 of the basket. ing. Inside the liquid introduction part 9B, there is formed a channel whose front end opens toward the peripheral wall part 101 of the basket and whose rear end communicates with the channel in the pusher plate penetration part 9A.

The push-out plate penetrating portion 9A shown in the figure includes a straight pipe portion 901 that penetrates the cake push-out plate 2 along the axial direction of the basket 1, and a straight pipe portion 901 that extends in the radial direction of the basket within the gap d and has a straight rear end portion. It consists of an L-shaped tube having a radial channel portion 902 connected to the end led out into the gap d of the tube portion 901, and a check to be described later is attached to the tip of the radial channel portion 902. An enlarged diameter portion 902a is formed to form the valve seat of the valve. The opening at the tip of the enlarged diameter portion 902a serves as an opening for opening the flow path in the pushing plate penetrating portion 9A into the gap d between the cake pushing plate 2 and the bottom wall portion 102 of the basket.

The liquid introduction portion 9B of the drainage device 9 used in this embodiment includes a base pipe portion 903 provided so as to extend along the radial direction of the basket 1, and is slidably supported by the base pipe portion 903. The movable portion 904 is displaced to the outer diameter side (upper side in FIG. 4) of the basket 1 by the centrifugal force generated by the rotation of the basket 1, and the movable portion 904 is displaced to the inner diameter side (lower side in FIG. 4) of the basket 1. and biasing means for biasing.

In the illustrated example, the movable portion 904 is composed of two tubular members 905 and 906 which are slidably fitted on the outer circumference of the base tube portion 903 and screwed together while being arranged in the axial direction of the base tube portion 903 . ing. Of the two tubular members 905 and 906, the tubular member 905 arranged on the center side of the basket and the tubular member 906 arranged on the peripheral wall portion 101 side are referred to as a first tubular member and a second tubular member, respectively.

A gap is formed between the inner peripheral surface of the movable portion 904 and the outer peripheral surface of the base tube portion 903, and a compression spring 907 fitted to the outer periphery of the main portion 903 is arranged in this gap to form a basket. One end 907a of the compression spring 907 directed toward the peripheral wall portion 101 of No. 1 is fixed to the outer periphery of the base tube portion 903 by suitable means such as welding. The other end 907b of the compression spring 907 facing away from the peripheral wall portion 101 of the basket 1 protrudes radially inward from the rear end portion of the first tubular member 905 positioned opposite to the second tubular portion 906. The movable portion 904 is received by the spring receiving portion 905a and urged by the spring 907 toward the inner diameter side of the peripheral wall portion 101 of the basket. In this embodiment, the spring 907 constitutes biasing means for biasing the movable portion 904 toward the inner diameter side of the basket (toward the center of the basket).

The expanded diameter portion 902a formed at the tip of the radial direction pipe portion 902 of the push plate penetration portion 9A closes the flow path in the drainage device 9 when the air pressure in the basket 1 is equal to or lower than the set pressure, thereby opening the basket. 1 to prevent the supernatant liquid formed in the drainage device 9 from flowing out into the gap d through the flow path in the drainage device 9, and when the air pressure in the basket 1 exceeds the set pressure, the inside of the drainage device 9 A check valve 910 is attached to open the flow path to allow the supernatant liquid in the basket 1 to flow out into the gap d through the flow path in the drainage device 9 .

The illustrated check valve 910 is a cylinder fitted to the outer periphery of the enlarged diameter portion 902a at the tip of the radial conduit portion 902 of the ejector plate penetration portion 9A of the drainage device 9, and having one end welded to the enlarged diameter portion 902a. A valve housing 911 having a shape and a contacting end face (valve seat) of an enlarged diameter portion 902a formed at the end of the radial direction pipe portion 902 and accommodated in the valve housing 911 in a slidably fitted state. A valve body 912, a coil spring 913 inserted into the valve housing 911 and having one end received by the valve body 912, and a male threaded portion on the outer periphery, the male threaded portion being closer to the other end of the valve housing 911. It consists of a tubular spring holding member 914 screwed into a female screw formed on the inner circumference of the valve body 912, and a coil spring arranged in a compressed state between the spring holding member 914 and the valve body 912. 913 urges the valve body 912 toward the enlarged diameter portion 902a.

The illustrated check valve 910 operates as follows. When the air pressure in the basket 1 is lower than the set pressure, the biasing force of the coil spring 913 keeps the valve element 912 in contact with the tip surface (valve seat) of the enlarged diameter portion 902a. The channel in the drainage device 9 is kept closed. In this state, the supernatant liquid in the basket is not discharged into the gap d between the cake pushing plate 2 and the bottom wall portion 102 of the basket through the channel in the drainage device 9 .

When the air pressure in the basket 1 exceeds the set pressure and a predetermined force is applied to the valve body 912 through the liquid in the flow path in the drainage device 9, the valve body 912 resists the biasing force of the coil spring 913 and expands in diameter. Since the check valve 910 is displaced in the direction away from the tip surface of the portion 902a, the flow path in the drainage device 9 is opened, and the supernatant liquid in the basket flows through the flow path in the drainage device 9 to the gap d. It will be in a state that allows it to be discharged inside. The pressure in the basket when the check valve 910 is opened can be appropriately adjusted by rotating the spring holding member 914 and adjusting the biasing force of the coil spring 913 .

In the illustrated drainage device 9, the movable portion 904 is biased toward the inner diameter side of the basket 1 by a spring 907, and is arranged at the initial position shown in FIG. 4 when the basket 1 is stopped. At the initial position of the movable portion 904, the open end 904t at the tip thereof is located at the specified position (see FIG. 4) at the end of the solid-liquid separation process on the inner peripheral surface of the cake layer C formed inside the peripheral wall portion 101 of the basket. is also set at a position on the inner diameter side.

When the rotational speed of the basket 1 is lower than the set speed, the biasing force of the spring 907 is stronger than the centrifugal force acting on the movable portion 904 due to the rotation of the basket 1, so the movable portion 904 is held at the initial position. . When the rotation speed of the basket 1 exceeds the set speed and the centrifugal force urging the movable portion 904 exceeds the urging force of the spring 907, the movable portion 904 starts to displace the basket 1 toward the peripheral wall portion. Therefore, after the solid-liquid separation process is completed, by increasing the rotation speed of the basket 1, the movable part 904 can be displaced toward the cake layer C while being immersed in the supernatant liquid layer W in the basket. can be done. The movable part 904 finally comes into contact with the inner peripheral surface of the cake layer C formed in the basket (makes a soft landing) and stops.

When the solid-liquid separation process is performed in the basket 1 and the cake layer C and the supernatant liquid layer W are formed in the solid-liquid separation processing chamber A2, the basket 1 is accelerated to move the movable portion 904 of the drainage device 9. is introduced into the supernatant liquid layer W, and high-pressure gas is supplied from the feed pipe 6 into the basket 1 to raise the pressure inside the basket 1 to a set pressure higher than the outside pressure. When the air pressure in the basket 1 exceeds the set pressure, the check valve 910 is opened to open the flow path in the drainage device 9, so that the supernatant liquid existing in the basket 1 is pushed out to the cake pushing plate 2 and the bottom wall portion 102 of the basket. The supernatant liquid discharged into the drainage chamber A1 is blown to the peripheral wall side of the basket 1 by the centrifugal force generated by the rotation of the basket 1. , is discharged out of the basket through the drain hole h. Since the movable portion 904 of the drainage device 9 finally reaches the position where it contacts the cake layer C, almost all of the supernatant liquid existing in the basket can be discharged out of the basket and recovered.

The initial position of the movable part 904 is set so that the opening end 904t of the movable part 904 is located on the inner diameter side of the inner peripheral surface of the supernatant liquid layer W formed in the basket when the solid-liquid separation process is completed. Alternatively, as shown in FIG. 4, the opening end 904t of the movable portion 904 is positioned outside the inner peripheral surface of the supernatant liquid layer W formed in the basket at the end of the solid-liquid separation process. It may be set so as to be positioned (so that the open end 904t of the movable part 904 is immersed in the supernatant liquid layer).

A driving device 10 (see FIG. 1) is provided to drive the basket 1 and the cake pushing plate 2 and lid plate 3 . The drive device 10 includes a rotary drive mechanism that rotates the basket 1 by rotating a main shaft 11 that is rotatably provided and one end of which is coupled to the bottom wall portion 102 of the basket 1, and a rotary drive mechanism that is provided inside the main shaft 11 so as to be thrust free. and a linear drive mechanism for linearly reciprocating the cake push-out plate 2 and the basket lid 3 in the axial direction of the basket 1 by driving a thrust shaft 12 whose tip end is connected to the cake push-out plate 2 .

A housing 13 is provided to accommodate the drive 10 . A housing 13 containing the driving device 10 includes a base B arranged on the installation surface S, a plate-shaped base frame 14 having a horizontal plate surface and fixed on the base B, and the base frame 14 . It has a main frame 15 which is arranged so that its plate surfaces are perpendicular to each other and whose lower end is fixed to a base frame 14 by welding or the like.

The main frame 15 includes a front side wall portion 15A standing vertically upward from the front end of the base frame 14, and a pair of side wall portions standing vertically upward from both ends of the base frame 14 in the width direction (direction perpendicular to the paper surface of FIG. 1). 15B and 15B are configured to have a U-shaped cross section. A cover 16 that covers the main portion of the driving device 10 is fixed to the frame 15 , and the main frame 15 and the cover 16 constitute a housing 13 that accommodates the main portion of the driving device 10 . The side walls 15B, 15B of the main frame 15 are appropriately provided with openings used for maintenance and inspection of the driving device 10, doors for opening and closing the openings, and the like.

A cylindrical casing 20 for accommodating the basket 1 is arranged in front of the front wall portion 15A of the main frame 15 with its axis oriented horizontally. 15 is fixed to the front wall portion 15A. A space between the casing 20 and the peripheral wall portion 101 of the basket 1 constitutes a liquid recovery chamber 21 . A drain pipe 22 is connected to the lower portion of the casing 20 so that the liquid recovered in the liquid recovery chamber 21 is recovered to the outside through the drain pipe 22 .

A front cover 23 is attached to the other end of the casing 20 housing the basket 1 . A cake discharge chute 23A is provided at the bottom of the front cover 23, and the cake collected from the basket is discharged downward through the cake discharge chute 23A. A space inside the front cover 23 constitutes a cake collection chamber 24 .

The feed pipe 6 has a length such that its tip reaches the inner side of the opening end of the basket 1, and closes the opening of the basket 1 when the cover plate 3 is in the closed position as shown in FIG. The tip position of the feed pipe 6 is set so that the tip of the feed pipe 6 passes through the cover plate 3 and opens into the basket 1 when the basket 1 is closed.

The feed pipe 6 is provided with its rear end (the end on the side opposite to the end introduced into the basket 1) penetrating the front end side wall 23a of the front cover 23. It is rotatably supported by the side wall 23a. A rotary joint 26 that connects the rotating pipe and the fixed pipe is supported via a support member 27 on the outside of the side wall 23a at the front end of the front cover 23. As shown in FIG. A rear end portion of the feed pipe 6 rotatably supported by the front cover 23 with a bearing 25 is connected to a rotation side joint of the rotary joint 26 via a joint 28 arranged inside the support member 27 . The fixed side joint of the rotary joint 26 is connected to a fixed pipe 29 selectively connected to the undiluted solution supply source, the cleaning solution supply source, and the high pressure gas supply source. Any one of the undiluted liquid, the cleaning liquid and the high-pressure gas is supplied into the basket 1 through the opening.

In this embodiment, the feed pipe 6, the rotary joint 26, the pipe 29, and the unillustrated undiluted solution supply source constitute the undiluted solution supply means for supplying the undiluted solution into the basket 1. The feed pipe 6, the rotary joint 26, and the pipe 29 are shown. A high-pressure gas supply means for supplying high-pressure gas into the basket 1 is constituted by the high-pressure gas supply source and the high-pressure gas supply source.

A driving device 10 for driving the basket 1, the cake push-out plate 2, and the cover plate 3 includes a rotation drive mechanism for rotating the basket 1 about its central axis, and a rotation drive mechanism for rotating the cake push-out plate 2 and the cover plate 3 together with the basket 1. and a linear drive mechanism that drives the basket 1 in the axial direction while moving it.

The rotation drive mechanism is composed of a hollow main shaft 11 coupled to the bottom wall portion 102 of the basket 1 and a mechanism for rotating the main shaft 11 . The linear drive mechanism is composed of a thrust shaft 12 provided in a hollow portion of the main shaft 11 so as to be freely thrustable, and a mechanism for linearly displacing the thrust shaft.

In the illustrated example, a bearing device 33 is supported by the base frame 14 via columns 31 and 32 , and one axial end of the bearing device 33 is coupled to the front wall portion 15 A of the main frame 15 . Bearings 34 and 35 are provided in the bearing device 33, and these bearings allow the hollow main shaft 11 to align its center axis with the center axis of the basket 1 with its center axis oriented laterally (horizontally). It is rotatably supported in alignment with the axis.

One end of the main shaft 11 in the axial direction is connected through a hole provided in the front wall portion 15A of the main frame 15 to the bottom wall portion 102 of the basket 1 disposed in front of the front wall portion 15A. The other end is led out from the other axial end of the bearing device 33 . One end and the other end in the axial direction of the main shaft 11 are defined as the front end and the rear end of the main shaft 11, respectively.

A main shaft drive motor 40 is supported by the base frame 14, and a toothed pulley 41 attached to the rear end of the main shaft 11 led out from the other end of the bearing device 33 and the rotating shaft of the main shaft drive motor 40 are attached. A timing belt 43 is wound around the toothed pulley 42 . The main shaft 11, the motor 40, the toothed pulleys 41 and 42, and the timing belt 43 constitute a rotary drive mechanism for rotating the basket 1 about its central axis.

The thrust shaft 12 is provided so as to share the center axis with the basket 1 and penetrate the main shaft 11 in the axial direction, and its tip is coupled to the cake pushing plate 2 . A slot 11a extending in the axial direction of the main shaft is formed in a part of the main shaft 11 in order to limit the allowable relative displacement between the thrust shaft 12 and the main shaft 11 to only the displacement along the axial direction of both shafts, A key 45 fixed to the thrust shaft 12 is slidably fitted in the slot 11a. One end and the other end of the thrust shaft 12 arranged on the front end side and the rear end side of the main shaft 11 are defined as the front end and the rear end of the thrust shaft 12, respectively. The front end of the thrust shaft 12 protrudes forward (toward the basket) from the front end of the main shaft 11 and is introduced into the basket 1 through a hole formed in the bottom wall portion 102 of the basket 1 .

The axial center of the thrust shaft 12 has a first hole 12a which opens on the side opposite to the basket and whose end on the basket side is closed, and a first hole 12a which opens on the side of the basket 1 and has an end on the side opposite to the basket 1. A closed second hole 12b is formed, and a threaded rod 51 screwed into a nut 50 fixed to the inner circumference of the portion near the rear end of the thrust shaft 12 is inserted into the first hole 12a. there is The second hole 12b is provided to receive the feed pipe 6 as shown in FIG. 2 while the thrust shaft 12 is advancing toward the basket 1 side.

The threaded rod 51 has a shaft portion 51a not provided with a screw at its rear end side. 54 and led out to the outside. A toothed portion forming a spline is formed on the shaft portion 51a of the threaded rod 51, and a toothed portion formed on the inner circumference of the toothed pulley 55 is meshed with a toothed portion formed on the shaft portion 51a of the threaded rod 51. As a result, the threaded rod 51 and the toothed pulley 55 are spline-connected.

A thrust shaft driving motor 56 is fixed to the frame 53 , and a toothed pulley 57 is attached to the output shaft of this motor 56 . A timing belt 58 is wound around a toothed pulley 57 and a toothed pulley 55 spline-connected to the threaded rod 51 so that the rotation of the motor 56 is transmitted to the threaded rod 51 via the belt 58. .

A flange plate 60 is fixed by a bolt 59 to the end of the threaded rod 51 that passes through the toothed pulley 55 and is led out to the side opposite to the basket 1 . A large number of coned disc springs 61 fitted to the threaded rod 51 are arranged in the axial direction. The disc spring 61 is provided in a compressed state in the axial direction of the threaded rod 51, and the disc spring 61 causes the threaded rod 51 and the thrust shaft 12 to move in the direction opposite to the opening direction of the basket 1 (to the right in FIG. 1). ) is energized. The disc spring 61 urges the cover plate 3 toward the basket 1 via the thrust shaft 12 and the cake pushing plate 2 connecting rod 4 when the basket cover 3 is placed at the closed position, thereby closing the cover plate 3. It acts as a positive hold in the closed position.

In the illustrated example, the thrust shaft drive mechanism drives the thrust shaft 12 forward and backward with respect to the main shaft 11 by means of a nut 50, a threaded rod 51, a motor 56, pulleys 57 and 55, and a belt 58. This drive mechanism and the thrust shaft 12 constitute a linear drive mechanism that rotates the cake pushing plate 2 and the cover plate 3 together with the basket 1 and drives it in the axial direction of the basket 1 .

In the illustrated driving device 10 , if only the motor 40 is driven out of the motors 40 and 56 , the rotation of the motor 40 causes the main shaft 11 to rotate, and the thrust shaft 12 coupled to the main shaft 11 via the key 45 is rotated. is rotated together with the main shaft 11 . When the thrust shaft 12 rotates, the nut 50 also rotates together with the thrust shaft, and the threaded rod 51 screwed to the nut 50 is also rotated. Since the rotation of the threaded rod 51 is transmitted to the pulley 57 through the pulley 55 and the belt 58, the rotating shaft of the motor 56 is rotated. In this state, the motor 56 is the load of the motor 40 , and the rotating shaft of the motor 56 is rotated by the motor 40 . Thus, when the motor 56 is rotated by the motor 40, the threaded rod 51 rotates together with the nut 50 and the thrust shaft 12, and there is no relative rotation between the threaded rod 51 and the nut 50. Therefore, the thrust shaft 12 does not perform thrust motion with respect to the main shaft 11 .

On the other hand, when the motor 56 is driven while the motor 40 is stopped, the threaded rod 51 rotates relative to the nut 50, so the nut 50 advances or retreats depending on the rotation direction of the motor 56. , the thrust shaft 12 fixed to the nut 50 advances or retreats as the nut 50 advances or retreats.

When the motors 40 and 56 are driven simultaneously, the threaded rod 51 rotates relative to the nut 50 according to the difference between the rotation speed of the main shaft 11 and the rotation speed of the threaded rod 51, and the nut of the threaded rod 51 rotates. Depending on the direction of rotation with respect to 50, thrust shaft 12 advances or retreats. At this time, the displacement speed of the thrust shaft 12 is proportional to the difference between the rotational speed of the threaded rod 51 and the rotational speed of the main shaft 11 . Therefore, by making the rotational speed of the threaded rod 51 higher or lower than the rotational speed of the main shaft 11, the thrust shaft 12 can be moved forward or backward.

Next, the operation of the centrifugal separator of this embodiment when performing solid-liquid separation processing for separating the undiluted liquid (slurry) into a liquid component and a cake component will be described. When performing a solid-liquid separation process, first, a liquid supply step is performed. In this liquid supply process, as shown in FIG. 1, the cake push-out plate 2 is positioned at the retracted position and the cover plate 3 is positioned at the closed position to seal the opening of the basket 1. The inside of the solid-liquid separation processing chamber A2 in the rotating basket 1 is rotated at an appropriate speed, and is supplied from the stock solution supply source (not shown) through the pipe 29, the rotary joint 26, and the feed pipe 6 for the set supply time. supply the undiluted solution to The liquid supply time is the time required for the inner circumferential position (liquid surface position) of the undiluted liquid in the basket to reach a specified position. This liquid supply time is obtained experimentally in advance. The specified position of the undiluted solution in the basket is set, for example, at a position slightly closer to the inner diameter side of the basket than the position of the tip of the movable portion 904 of the drainage device 9 .

When the liquid supply time has elapsed, the supply of the undiluted solution into the basket is stopped, and the basket is accelerated to the speed of the solid-liquid separation treatment to carry out the solid-liquid separation treatment process. In this step, the centrifugal force generated by the rotation of the basket causes the cake, which has a large specific gravity, to settle toward the peripheral wall of the basket. A supernatant liquid layer W is formed inside. After performing the solid-liquid separation process for a set time, a liquid drainage process is performed to discharge the supernatant liquid present in the basket to the outside of the basket.

In this draining step, high-pressure gas is supplied through the feed pipe 6 into the solid-liquid separation chamber A2 of the basket 1 to raise the air pressure in the solid-liquid separation chamber A2 to a set pressure (eg, 5 kg/cm ² ) or higher. At the end of the solid-liquid separation treatment process, since a dense cake layer C is formed on the inner circumference of the portion of the peripheral wall of the basket facing the solid-liquid separation treatment chamber A2, the outer peripheral portion of the cake pushing plate 2 and the peripheral wall of the basket Gas does not leak to the drain chamber A1 side through the gap with the inner peripheral portion of 101 . Therefore, pressurization in the solid-liquid separation processing chamber can be carried out without any trouble even if no measures are taken to close the gap between the outer peripheral portion of the cake pushing plate 2 and the inner peripheral portion of the peripheral wall portion 101 of the basket. can be done.

By pressurizing the interior of the solid-liquid separation processing chamber, the check valve 908 provided in the drainage device 9 is opened, thereby allowing the liquid to flow through the flow path in the drainage device 9, and the liquid is discharged into the basket. The supernatant liquid present is drained through the drainage device 9 into the drainage chamber A1. The liquid discharged into the drainage chamber A1 is blown to the side of the peripheral wall of the basket by the centrifugal force generated by the rotation of the basket, and is discharged out of the basket through the drainage holes h. In the drainage step, the rotating speed of the basket is further increased to displace the movable portion 904 of the drainage device 9 toward the peripheral wall portion of the basket by centrifugal force. Since the movable portion 904 is finally displaced until its tip comes into contact with the cake layer C, almost all of the supernatant liquid present in the basket is drained through the drainage device 9, the drainage chamber A1 and the drainage hole h. can be discharged to the outside of the basket through the

After the liquid draining process has been performed for the set time, the rotational speed of the basket is reduced to the rotational speed at the time of liquid supply, and the undiluted liquid is supplied through the feed pipe 6 into the solid-liquid separation processing chamber A2 in the basket, and solidified again. After performing the liquid separation treatment process for a predetermined period of time, the liquid draining process is performed for a predetermined period of time to discharge the supernatant liquid in the basket out of the basket. A liquid supply process, a solid-liquid separation process, and a liquid drainage process are repeated a predetermined number of times, and when a cake layer C having a predetermined thickness is formed in the basket, a series of processes consisting of a liquid supply process and a liquid drainage process is performed. finish. Optimum values for the times for performing the liquid supply process, the solid-liquid separation treatment process and the liquid drainage process, and the number of repetitions of these processes are determined in advance by experiments for each raw liquid to be processed. After the liquid draining process is completed, if necessary, a cleaning process in which cleaning liquid is supplied into the basket through the feed pipe 6 to wash the inside of the basket, and a liquid draining process in which the cleaning liquid is discharged out of the basket through the liquid drainer 9. After performing the above, a cake discharging process for discharging the cake from the basket 1 is performed.

In the cake discharge process, the cake push-out plate 2 is displaced toward the forward position while rotating the basket 1 together with the cake push-out plate 2 and the cover plate 3 at a predetermined rotational speed, and the cake push-out plate 2 pushes the cake out of the opening of the basket. The flexible sleeve 7 is pushed out into the cake recovery chamber and the cake adhering to the flexible sleeve 7 is dropped into the cake recovery chamber 24 by reversing the flexible sleeve 7.例文帳に追加

In the above-described embodiment, separation of the liquid component and the cake component is performed exclusively by centrifugal sedimentation without providing a through hole through which the liquid component permeates the peripheral wall portion of the basket. As a centrifugal separator, a large number of through holes are provided in the peripheral wall of the basket, and a filter cloth (filter) is arranged on the inner circumference of the peripheral wall of the basket, and the centrifugal force generated by the rotation of the basket separates the stock solution. Filtration-type centrifuges are often used to separate fractions and cake fractions. When the cake layer is formed, the liquid cannot pass through the cake layer and reach the perforations of the peripheral wall of the basket, so that solid-liquid separation cannot be performed sufficiently. On the other hand, if the solid-liquid separation process is performed by centrifugal sedimentation, there is no need to remove the liquid through the cake layer, so even if the crystals or particles of the cake are fine, the solid-liquid separation process can be performed without any problems. be able to.

In the above-described embodiment, solid-liquid separation is performed exclusively by centrifugal sedimentation without providing through holes in the peripheral wall of the basket. A through hole may be provided so that it can also be used as a filtration type centrifugal separator. When configured in this manner, the centrifugal separator is operated as a filtering type when the crystal particles contained in the undiluted solution are not minute, and is operated as a centrifugal sedimentation type centrifugal separator when the particles of the cake are minute. Thus, a single centrifugal separator can perform both solid-liquid separation using centrifugal sedimentation and solid-liquid separation using filtration. In this case, as the flexible sleeve 7, one having a filtering function such as a filter cloth is used.

Even when a basket having a large number of through-holes in the peripheral wall is used, a sheet made of a liquid-impermeable material is arranged on the inner periphery of the portion of the peripheral wall of the basket 1 that constitutes the solid-liquid separation processing chamber A2. By covering the perforation of the peripheral wall of the basket with the sheet, solid-liquid separation can be performed only by the centrifugal sedimentation action.

In the above embodiment, the flexible sleeve 7 is provided between the inner periphery of the opening of the basket and the outer periphery of the cake push-out plate. The cake may be discharged out of the basket by . If no flexible sleeve is provided, the advance position of the cake push-out plate 2 can be set near the opening of the basket or can be set in front of the opening of the basket.

In the above embodiment, the airtightness of the feed pipe introduction part of the cover plate 3 is facilitated, and the pressure inside the basket can be easily maintained higher than the outside air pressure when the supernatant liquid is discharged from the basket. For this purpose, the feed pipe 6 is configured to rotate together with the basket 1, but the present invention is not limited to such a configuration, and there is a relative position between the feed pipe 6 and the cover plate 3. If a sealing means capable of maintaining the airtightness in the basket even when it is rotated can be employed in the feed pipe introducing portion of the cover plate 3, the feed pipe 6 is fixed to the front cover 23 and the basket is closed. The lid plate 3 may be configured to rotate relative to the feed pipe 6 . In this case, the rotary joint 26 used in the above embodiment becomes unnecessary.

In the above-described embodiment, the radial duct portion 902 extending in the radial direction of the basket is provided in the pusher plate penetration portion 9A of the drainage device 9. The end portion of the channel in 9A on the gap d side may be opened to the bottom wall portion 102 side of the basket 1 .

In the above embodiment, a check valve is provided at the end of the drainage device 9 on the side of the gap d to open the flow path in the drainage device 9 when the pressure in the solid-liquid separation chamber of the basket exceeds the set pressure. However, the check valve may be provided on the liquid introduction portion 9B side of the drainage device 9. FIG.

1 Basket 101 Basket Peripheral Wall 102 Basket Bottom Wall 103 Basket Opening 2 Cake Ejection Plate 2a One Side of Cake Ejection Plate 2b Other Side of Cake Ejection Plate d Gap Between Cake Ejection Plate and Basket Bottom Wall h drainage hole A1 drainage chamber A2 solid-liquid separation processing chamber 3 cover plate 4 connecting rod 6 feed pipe 7 flexible sleeve 9 drainage device 9A extrusion plate penetration part of drainage device 9B liquid introduction part of drainage device 904 Movable part 907 Spring for biasing the movable part 10 Driving device for driving the basket and the cake pushing plate 11 Main shaft 11a Slot provided in the main shaft 12 Thrust shaft 13 Housing containing the driving device 20 Cylindrical casing containing the basket 21 Liquid Minute collection chamber 22 Drain pipe 23 Front cover constituting cake collection chamber 24 Cake collection chamber 40 Motor for driving main shaft 41 Pulley 42 Pulley 43 Belt 45 Key attached to thrust shaft 50 Nut 51 Threaded rod 55 Pulley 56 Threaded rod motor for driving 57 pulley 58 belt

Claims (7)

A basket having a peripheral wall, one axial end of which is closed by a bottom wall, and an opening provided on the other axial end of the basket is rotated, and the undiluted solution supplied into the basket is subjected to centrifugal sedimentation. A centrifugal separator that performs a solid-liquid separation process for separating into a fraction and a cake fraction,
One surface and the other surface are oriented toward the bottom wall of the basket and the side opposite to the bottom wall, respectively, and are provided so as to rotate together with the basket, and the one surface is inside the basket and the bottom wall of the basket. and a forward position set at the opening of the basket or in front of the opening along the axial direction of the basket. a cake pusher plate provided to obtain
a cover plate that airtightly closes the opening of the basket when the cake push-out plate is in the retracted position, and opens the opening of the basket in the process of displacing the cake push-out plate toward the forward position;
It is attached to the cake push-out plate with a part penetrating the cake push-out plate, and the liquid flows from the other side of the cake push-out plate through the cake push-out plate to the one side of the cake push-out plate. a drainage device having a channel therein;
a drainage hole penetrating the basket at a position facing a gap between one surface of the cake pushing plate and the bottom wall of the basket;
and
With the cake push-out plate positioned at the retracted position and the opening of the basket closed by the cover plate, the pressure inside the basket is set to a set pressure higher than the outside air pressure. The existing supernatant liquid is discharged to the outside of the basket through the channel and the drainage hole in the drainage device, and the cake push-out plate is displaced from the retracted position toward the advanced position to remove the cake in the basket. is pushed out of the basket to discharge the cake in the basket to the outside. A basket having a peripheral wall, one axial end of which is closed by a bottom wall, and an opening provided on the other axial end of the basket is rotated, and the undiluted solution supplied into the basket is subjected to centrifugal sedimentation. A centrifugal separator that performs a solid-liquid separation process for separating into a fraction and a cake fraction,
One surface and the other surface are oriented toward the bottom wall of the basket and the side opposite to the bottom wall, respectively, and are provided so as to rotate together with the basket, and the one surface is inside the basket and the bottom wall of the basket. provided so as to be displaceable along the axial direction of the basket between a retracted position set in a position facing the basket with a gap therebetween and an advanced position set in front of the opening of the basket. a cake pusher plate;
a cover plate that airtightly closes the opening of the basket when the cake push-out plate is in the retracted position, and opens the opening of the basket in the process of displacing the cake push-out plate toward the forward position;
It is formed in a cylindrical shape from a flexible material and has one end fixed to the opening of the basket and the other end fixed to the outer peripheral portion of the cake push-out plate so that the cake push-out plate is in the retracted position. a flexible sleeve that is sometimes arranged in a state of covering the inner periphery of the peripheral wall portion of the basket, and that is reversed in the process of displacing the cake pushing plate from the retracted position toward the forward position;
It is attached to the cake push-out plate with a part penetrating the cake push-out plate, and the liquid flows from the other side of the cake push-out plate through the cake push-out plate to the one side of the cake push-out plate. a drainage device having a channel therein;
a drainage hole penetrating the basket at a position facing a gap formed between one surface of the cake pushing plate and the bottom wall of the basket;
and
With the cake push-out plate positioned at the retracted position and the opening of the basket closed by the cover plate, the pressure inside the basket is set to a set pressure higher than the outside air pressure. The existing supernatant liquid is discharged to the outside of the basket through the channel and the drainage hole in the drainage device, and the cake push-out plate is displaced from the retracted position toward the advanced position, and the cake push-out plate A centrifugal separator configured to discharge the cake in the basket to the outside of the basket by inverting the flexible sleeve while pushing out the cake in the basket. The drainage device has a portion penetrating the cake push-out plate along the axial direction of the basket at a position eccentric from the rotation center axis of the basket, and draining the cake push-out plate from the other side of the cake push-out plate. A push plate penetration portion having a flow path for flowing a liquid to one side of the cake push plate through and a rear end portion at one end of the push plate penetration portion arranged on the other side of the cake push plate are connected to each other, and the flow is provided with the tip directed toward the peripheral wall of the basket, the tip opening toward the peripheral wall of the basket, and the rear end communicating with the flow path in the push plate penetration part. a liquid introduction part having a channel inside,
On the other end side of the push-plate penetration portion arranged on the one side of the cake push-out plate, the flow path in the push-plate penetration portion is formed in the gap between the cake push-out plate and the bottom wall portion of the basket. An opening is provided to open,
The liquid introduction part of the drainage device includes a movable part that is displaced toward the outer diameter side of the basket by a centrifugal force generated as the basket rotates, and biases the movable part toward the inner diameter side of the basket. a biasing means;
When the air pressure in the basket is below the set pressure, the liquid in the basket is prevented from flowing out into the gap through the channel in the drainage device, and the air pressure in the basket exceeds the set pressure. 3. The centrifugal device according to claim 1 or 2, wherein a check valve is provided in said drainage device to allow the liquid in said basket to flow out into said gap through a channel in said drainage device when the separation device. 4. The centrifugal separator according to claim 3, wherein the check valve is provided on an opening side for opening the flow path in the drainage device into a gap between the cake pushing plate and the bottom wall of the basket. Device. 4. The centrifugal separator according to claim 3, wherein said check valve is provided in a liquid introduction portion of said drainage device. Among the parts of the peripheral wall of the basket, the part located closer to the opening of the basket than the cake pushing plate in the retracted position is configured so as not to allow liquid to permeate, and the solid-liquid separation process includes: 6. The centrifugal separator according to any one of claims 1 to 5, wherein centrifugal sedimentation is performed by centrifugal sedimentation caused by rotation of said basket. Among the various parts of the peripheral wall of the basket, a large number of through holes for allowing liquid to permeate are formed in a part located closer to the opening of the basket than the cake push-out plate in the retracted position,
3. The centrifugal separator of claim 2, wherein the flexible sleeve is made of a filter material having a liquid-permeable function.

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