JP2021115595A - Screw press - Google Patents

Abstract

To provide a screw press that reliably prevents sludge from entering an internal space of a screw.SOLUTION: A screw press includes a filtration cylinder 1, a first screw 3 and a second screw 4 and a bearing 30A. The second screw 4 includes a second screw shaft 4A. A squeezing flow passage CH1 for squeezing a liquid-containing matter is formed between the filtration cylinder 1, a first screw shaft 3A and the second screw shaft 4A. The bearing 30A includes a penetration flow passage 200 for communicating a closed space SP1 formed between the first screw shaft 3A and the second screw shaft 4A to the squeezing flow passage CH1.SELECTED DRAWING: Figure 3

Description

The present invention relates to a screw press that squeezes a liquid-containing material such as sludge to separate the liquid from the liquid-containing material.

Conventionally, a screw press has been used as a device for squeezing sludge (liquid-containing matter) discharged from a liquid treatment facility such as a water and sewage treatment plant and a urine treatment plant to separate (that is, dehydrate) water from the sludge. Are known.

The screw press includes a filter tube formed of a screen (perforated plate) and a screw arranged inside the filter tube. The screw squeezes the sludge put into the filter tube and dehydrates it. The dehydrated sludge (cake) is discharged from the discharge side end of the filtration tube.

Japanese Unexamined Patent Publication No. 2010-253536 Japanese Unexamined Patent Publication No. 2018-15582

However, the squeezed sludge may enter the internal space of the screw. The sludge that has entered this internal space may adversely affect the operation of the screw press. Alternatively, the work of discharging the sludge existing in the internal space requires a great deal of time and effort.

Therefore, an object of the present invention is to provide a screw press that reliably prevents sludge from entering the internal space of the screw.

In one aspect, a filter cylinder into which the liquid-containing material is charged, and a first screw and a second screw which are arranged concentrically with the filter cylinder in the filter cylinder and transfer the liquid-containing material in a predetermined transfer direction. And a bearing arranged between the first screw and the second screw, the second screw is a second screw shaft having a recess into which the first screw shaft of the first screw is inserted. A squeeze flow path through which the liquid-containing material is squeezed is formed between the filter cylinder and the first screw shaft and the second screw shaft. Provided is a screw press having a closed space formed between the first screw shaft and the second screw shaft and a through flow path for communicating the squeezing flow path.

In one aspect, the through flow path is a groove formed on the surface of the bearing.
In one aspect, the through flow path is a through hole formed in the bearing.

In one aspect, the second screw includes a drainage hole formed in the second screw shaft and a drainage plug that closes the drainage hole.
In one aspect, the second screw comprises a lubricating fluid injection hole formed in the second screw shaft and an injection plug that closes the lubricating fluid injection hole.
In one aspect, the screw press comprises a pressure detecting device that detects the internal pressure of the enclosed space.

The bearing communicates the enclosed space and the squeezed flow path with each other through the through flow path. Therefore, the pressure in the enclosed space is the same as the pressure in the squeezing channel increased by the squeezing of the sludge. As a result, there is no pressure difference between the squeezed channel and the closed space, and sludge does not enter the closed space.

It is a schematic diagram which shows the screw press which concerns on one Embodiment. It is the schematic sectional drawing of the 2nd screw shown in FIG. It is the schematic sectional drawing which shows the other embodiment of the 2nd screw. It is an enlarged view of a bearing. It is a perspective view of a bearing. It is a figure which shows the other embodiment of the through flow path. It is a figure which shows the lubricating liquid injection hole formed in the reduced diameter part of the 2nd screw shaft, and the injection plug which closes the lubricating liquid injection hole. It is a figure which shows the pressure detection device which detects the internal pressure of a closed space.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view showing a screw press according to an embodiment. The screw press shown in FIG. 1 is arranged concentrically with the cylindrical screen casing (filtration cylinder) 1 and the screen casing 1 in the screen casing 1, and sludge (liquid content) is transferred in a predetermined transfer direction D. The first screw 3 and the second screw 4 to be transferred, the first rotating mechanism 7 for rotating the first screw 3, and the second rotating mechanism 20 for rotating the second screw 4 independently of the first screw 3 are provided. I have.

The screen casing 1 is formed of a screen (perforated plate) such as punching metal. A sludge inlet 2 is formed at the upstream end of the screen casing 1. The sludge charged into the screen casing 1 from the charging port 2 is transferred in the screen casing 1 in a predetermined transfer direction D by the rotating first screw 3 and the second screw 4. Further, the screw press has a control unit 6 that controls the operation of the first rotation mechanism 7 and the second rotation mechanism 20.

The second screw 4 is connected to the first screw 3 so that it can rotate independently of the first screw 3. The first screw 3 and the second screw 4 extend through the screen casing 1 and the discharge chamber 33, respectively. The discharge chamber 33 is connected to the screen casing 1. A plug cake, which will be described later, is discharged from the screen casing 1 into the discharge chamber 33. The axial length of the second screw 4 is shorter than the axial length of the first screw.

The first screw 3 is fixed to the outer surface of the first screw shaft 3A having a truncated cone shape (tapered shape) and the first screw shaft 3A whose diameter gradually increases toward the downstream side in the sludge transfer direction D. It has a first screw blade 3B. The second screw 4 has a cylindrical second screw shaft 4A and a second screw blade 4B fixed to the outer surface of the second screw shaft 4A. The second screw 4 is arranged on the downstream side of the first screw 3 in the sludge transfer direction D.

The upstream end of the screen casing 1 is sealed by a closing wall 8. One end of the first screw shaft 3A (upstream end in the transfer direction D) extends through the closing wall 8. A water sealing device 10 for sealing the gap between the closing wall 8 and the first screw shaft 3A is installed on the closing wall 8. The upstream end of the first screw shaft 3A extending through the closing wall 8 is rotatably supported by bearings 11 and 12 installed on the base (not shown) while restraining axial movement. .. One of the bearings 11 and 12 can be omitted.

The upstream end of the first screw shaft 3A is connected to a first rotation mechanism 7 for rotating the first screw 3. In the present embodiment, the first rotation mechanism 7 includes a first drive (for example, an electric motor) 14, a sprocket 15 fixed to the rotation shaft of the first drive 14, and a sprocket fixed to the first screw shaft 3A. A 16 and a chain 17 wound around the sprockets 15 and 16 are provided.

The sprocket 16 is located between the bearings 11 and 12. When the first drive machine 14 of the first rotation mechanism 7 is driven, the sprocket 15 fixed to the rotation shaft of the first drive machine 14 rotates, and the sprocket 16 fixed to the first screw shaft 3A via the chain 17 To rotate. As a result, the first screw 3 is rotated by the first rotation mechanism 7. The first drive unit 14 is connected to the control unit 6, and the control unit 6 is configured to be able to control the operation of the first drive unit 14.

Although not shown, the rotating shaft of the first driving machine 14 may be connected to the first screw shaft 3A via a speed reducer. Alternatively, the rotating shaft of the first driving machine 14 may be directly connected to the first screw shaft 3A.

FIG. 2 is a schematic cross-sectional view of the second screw 4 shown in FIG. As shown in FIG. 2, the second screw shaft 4A has a hollow structure. At the other end of the first screw shaft 3A (downstream end in the transfer direction D), a reduced diameter portion 3C to be inserted into the cylindrical second screw shaft 4A is formed.

By forming the reduced diameter portion 3C on the first screw shaft 3A, a wall surface 3D perpendicular to the axial direction is formed on the first screw shaft 3A. The reduced diameter portion 3C is inserted into the cylindrical second screw shaft 4A and is rotatably supported by the slide bearings 30 and 31 fixed to the inner wall 4C of the second screw shaft 4A. With such a configuration, the first screw 3 is rotatably connected to the second screw 4.

As shown in FIGS. 1 and 2, the second screw shaft 4A of the second screw 4 is arranged concentrically with the first screw shaft 3A. The outer diameter of the second screw shaft 4A is the same as the maximum diameter of the first screw shaft 3A. The second screw shaft 4A is formed with a reduced diameter portion 4F extending through the inner wall 33A of the discharge chamber 33. By forming the reduced diameter portion 4F on the second screw shaft 4A, a wall surface 4D perpendicular to the axial direction is formed on the second screw shaft 4A.

The upstream end of the second screw shaft 4A is rotatably supported by the first screw shaft 3A via the slide bearings 30 and 31, and the downstream end of the second screw shaft 4A is a base (not shown). ), The bearings 22 and 23 are rotatably supported while restraining the movement in the axial direction. The bearing 23 can be omitted.

The downstream end of the second screw shaft 4A is connected to a second rotation mechanism 20 for rotating the second screw 4. In the present embodiment, the second rotation mechanism 20 includes a second drive machine (for example, an electric motor) 24, a sprocket 25 fixed to the rotation shaft of the second drive machine 24, and a sprocket fixed to the second screw shaft 4A. A 26 and a chain 27 wound around these sprockets 25 and 26 are provided.

The sprocket 26 is located between the bearings 22 and 23. When the second drive machine 24 of the second rotation mechanism 20 is driven, the sprocket 25 fixed to the rotation shaft of the second drive machine 24 rotates, and the sprocket 26 fixed to the second screw shaft 4A via the chain 27. To rotate. As a result, the second screw 4 is rotated by the second rotation mechanism 20.

The second drive unit 24 is connected to the control unit 6. The second drive machine 24 has a built-in inverter (not shown), and the control unit 6 is configured to be able to control the operation of the second drive machine 24 via the inverter. That is, the control unit 6 can control the rotation speed and the rotation direction of the second drive machine 24 via the inverter. The second drive machine 24 can rotate the second screw 4 independently of the first screw 3. It is preferable that the first drive machine 14 also has a built-in inverter capable of changing the rotation speed and the rotation direction of the first drive machine 14.

Although not shown, the rotating shaft of the second drive machine 24 may be connected to the second screw shaft 4A via a speed reducer. Alternatively, the rotating shaft of the second drive machine 24 may be directly connected to the second screw shaft 4A.

The first screw blade 3B extends spirally along the axial direction of the first screw shaft 3A, and the second screw blade 4B spirally extends along the axial direction of the second screw shaft 4A. The total length of the portion of the first screw 3 to which the first screw blade 3B is fixed and the portion of the second screw 4 to which the second screw blade 4B is fixed is the axial length of the screen casing 1. Same or longer.

A minute gap is formed between the inner surface of the screen casing 1 and the first screw blade 3B so that the first screw blade 3B can rotate without contacting the screen casing 1. Similarly, a minute gap is formed between the inner surface of the screen casing 1 and the second screw blade 4B, so that the second screw blade 4B can rotate without contacting the screen casing 1. ing.

The sludge charged into the screen casing 1 from the inlet 2 formed at the upstream end of the screen casing 1 is transferred toward the discharge chamber 33 by the rotating first screw blades 3B and the second screw blades 4B (that is, transferred). Can be transferred (in direction D).

In the present embodiment, the winding direction of the second screw blade 4B (that is, the spiral direction) is opposite to the winding direction of the first screw blade 3B. Therefore, when the sludge charged from the charging port 2 is sent out to the discharge chamber 33, the second screw 4 is rotated in the direction opposite to that of the first screw 3, as shown in FIG.

In one embodiment, the winding direction of the second screw blade 4B may be the same as the winding direction of the first screw blade 3B. In this case, when the sludge charged from the charging port 2 is sent out to the discharge chamber 33, the second screw 4 is rotated in the same direction as the first screw 3.

As shown in FIG. 1, the screen casing 1 is divided into a dehydration region 1A in which the first screw 3 is arranged and a plug forming region 1B in which the second screw 4 is arranged. The space to which sludge is transferred in the dehydration region 1A is formed by the inner surface of the screen casing 1, the first screw blade 3B, and the first screw shaft 3A.

As shown in FIG. 1, the cross-sectional area of this transfer space gradually decreases along the sludge transfer direction D. Therefore, as the sludge charged from the charging port 2 is transferred through this transfer space by the first screw blade 3B, the sludge is squeezed and dehydrated. The filtrate that has passed through the screen (perforated plate) of the screen casing 1 is collected by the filtrate receiver 38 arranged below the screen casing 1. A drain 39 is connected to the filtrate receiver 38, and the filtrate collected by the filtrate receiver 38 is discharged from the screw press via the drain 39.

The space to which sludge is transferred in the plug forming region 1B is formed by the inner surface of the screen casing 1, the second screw blade 4B, and the second screw shaft 4A. As shown in FIG. 1, the cross-sectional area of this transfer space is constant. In the plug forming region 1B, the plug cake is formed by the sludge (that is, the cake) dehydrated in the dehydrating region 1A. The method for forming the plug cake is as follows.

The sludge charged from the charging port 2 is transferred toward the second screw 4 (that is, in the transfer direction D) by the rotating first screw blade 3B without staying in place. The sludge is squeezed as it is transferred through the dehydration region 1A, and the liquid contained in the sludge is filtered by the screen casing 1. While the sludge is transferred through the dehydration region 1A of the screen casing 1, the sludge is dehydrated into a cake and sent to the plug forming region 1B where the second screw 4 is arranged.

At the beginning of operation, since the second screw 4 is not rotating (that is, stopped), the cake in the plug forming region 1B is not discharged to the discharge chamber 33, but stays in the plug forming region 1B. The cake is gradually accumulated on the second screw 4 and pressed against the second screw blade 4B by sludge (hereinafter referred to as “subsequent cake”) transferred from the dehydration region 1A to the plug forming region 1B.

The cake in the plug forming region 1B is squeezed by being hindered from moving by the second screw blade 4B, and becomes a cake having a low water content. This low moisture content cake forms a plug cake that impedes subsequent cake movement. Back pressure is applied to the subsequent cake by the plug cake formed around the second screw shaft 4A, and the subsequent cake is further squeezed. The liquid separated from the plug cake in the plug forming region 1B is collected by the filtrate receiver 38 and discharged from the screw press via the drain 39.

As the operation of the screw press is continued, the plug cake is uniformly formed over the entire circumference of the second screw shaft 4A. As a result, a plug cake that reliably dams the subsequent cake is formed around the second screw shaft 4A. Therefore, even when the water content of the subsequent cake is high, the plug cake formed in the plug forming region 1B can reliably block the subsequent cake, so that one-sided flow of the subsequent cake can be prevented. This "one-sided flow" means that a subsequent cake having a higher water content than the plug cake passes through the plug forming region 1B as it is and is discharged to the discharge chamber 33.

In the following embodiment, the configuration of the screw press capable of reliably preventing sludge from entering the internal space of the second screw shaft 4A will be described with reference to the drawings.

As described above, the sludge charged from the charging port 2 is squeezed as it is transferred by the first screw blade 3B and the second screw blade 4B. Therefore, the squeezed sludge may pass through the slide bearings 30 and 31 (see FIG. 2) fixed to the inner wall 4C of the second screw shaft 4A and enter the internal space of the second screw shaft 4A. The sludge that has entered the internal space may hinder the smooth rotation of the first screw 3 and the second screw 4. Therefore, in the embodiment shown below, the screw press has a structure that reliably prevents sludge from entering the internal space of the second screw shaft 4A.

FIG. 3 is a schematic cross-sectional view showing another embodiment of the second screw 4. In the present embodiment, the same or corresponding members as those in the above-described embodiment are designated by the same reference numerals, and duplicate description will be omitted. As shown in FIG. 3, the second screw 4 includes a second screw shaft 4A having a recess into which the first screw shaft 3A of the first screw 3 is inserted. More specifically, the second screw shaft 4A has an end wall 4E formed on the inner wall 4C. The recess is composed of an inner wall 4C and an end wall 4E.

The end wall 4E of the second screw shaft 4A is provided on the reduced diameter portion 4F formed on the wall surface 4D of the second screw shaft 4A. The reduced diameter portion 4F extends from the wall surface 4D toward the bearings 22 and 23, and is supported by the bearings 22 and 23. In the embodiment shown in FIG. 3, the end wall 4E is arranged between the outermost end 4F-1 of the reduced diameter portion 4F and the wall surface 4D, but in one embodiment, the end wall 4E is the reduced diameter portion. It may be connected to the outermost end 4F-1 of 4F.

As shown in FIG. 3, the tip 3C-1 of the reduced diameter portion 3C of the first screw shaft 3A inserted into the second screw shaft 4A is arranged adjacent to the end wall 4E of the second screw shaft 4A. There is. When the reduced diameter portion 3C is inserted into the second screw shaft 4A, a closed space SP1 is formed between the reduced diameter portion 3C and the recesses of the second screw shaft 4A (that is, the inner wall 4C and the end wall 4E). NS.

As shown in FIG. 3, the bearing 30A and the bearing 31A are arranged between the first screw shaft 3A of the first screw 3 and the second screw shaft 4A of the second screw 4. Each of these bearings 30A and 31A is, for example, a plain bearing. The bearing 30A is arranged adjacent to the wall surface 3D formed on the first screw shaft 3A, and the bearing 31A is arranged adjacent to the tip 3C-1 of the reduced diameter portion 3C.

FIG. 4 is an enlarged view of the bearing 30A. As shown in FIGS. 3 and 4, a squeezing flow path CH1 in which sludge is squeezed is formed between the screen casing 1 and the first screw shaft 3A and the second screw shaft 4A. The bearing 30A has a through flow path 200 for communicating the closed space SP1 formed between the first screw shaft 3A and the second screw shaft 4A and the squeezing flow path CH1.

FIG. 5 is a perspective view of the bearing 30A. In the embodiment shown in FIG. 5, the through flow path 200 is a groove formed on the surface of the bearing 30A. The surface of the bearing 30A is a general term for the outer surface 30A-1 and the inner surface 30A-2 of the bearing 30A. Therefore, the through flow path 200 may be formed on the outer surface 30A-1 of the bearing 30A and / or may be formed on the inner surface 30A-2 of the bearing 30A.

As shown in FIG. 5, the bearing 30A includes a tubular portion 201 extending in parallel with the reduced diameter portion 3C of the first screw shaft 3A, and an annular portion 202 arranged so as to project from the tubular portion 201. .. The tubular portion 201 and the annular portion 202 are arranged perpendicular to each other. The tubular portion 201 is a portion that receives a radial force acting on the first screw shaft 3A (and / or the second screw shaft 4A), and the annular portion 202 is a portion that receives the first screw shaft 3A (and / or the second screw shaft 4A). ) Is the part that receives the thrust force.

In the embodiment shown in FIG. 5, the through flow path 200 is formed on the outer surface 30A-1 of the tubular portion 201, and is formed on the first flow path 200a extending parallel to the axial direction CL and the surface 202b of the annular portion 202. A second flow path 200b extending in the radial direction of the annular portion 202 (that is, a direction perpendicular to the axial direction CL) and a third flow formed on the peripheral edge portion 202a of the annular portion 202 and extending parallel to the axial direction CL. It is equipped with a road 200c. The first flow path 200a, the second flow path 200b, and the third flow path 200c are connected so as to form one flow path. The first flow path 200a is connected to the end surface 201a of the tubular portion 201.

In this way, the bearing 30A having the through flow path 200 communicates the closed space SP1 and the squeeze flow path CH1 with each other through the through flow path 200. Therefore, the pressure in the closed space SP1 becomes the same as the pressure in the squeezing flow path CH1 increased by squeezing the sludge. As a result, no pressure difference is generated between the squeezed flow path CH1 and the closed space SP1, and sludge moving in the squeezed flow path CH1 does not enter the closed space SP1.

In the embodiment shown in FIG. 5, the bearing 30A has a tubular portion 201 and an annular portion 202, but the structure of the bearing 30A is not necessarily limited to the embodiment shown in FIG. In one embodiment, the bearing 30A may have a cylindrical shape that receives radial and thrust forces. In this case, the bearing 30A has a through flow path 200 extending parallel to its axial direction.

FIG. 6 is a diagram showing another embodiment of the through flow path 200. As shown in FIG. 6, the through flow path 200 may be a through hole formed in the bearing 30A. In the embodiment shown in FIG. 6, the through flow path 200 is opened at the end surface 201a of the tubular portion 201 and the peripheral edge portion 202a of the annular portion 202. Bearing 30A may have both grooves and through holes.

As described above, since the screw press includes a bearing 30A (and a bearing 31A) having a through flow path 200, it is possible to prevent sludge from entering the closed space SP1. Generally, a sealing member is provided on a bearing (not shown) arranged between the first screw shaft 3A and the second screw shaft 4A to prevent sludge from entering. However, since the seal member is a consumable part, it is necessary to replace the seal member on a regular basis. In order to replace the seal member, it is necessary to perform a large-scale work for removing the first screw shaft 3A from the second screw shaft 4A. According to the embodiment shown in FIGS. 3 to 6, sludge can be prevented from entering without providing the seal member, so that a large-scale work for replacing the seal member can be omitted.

Although not shown, the bearing 31A may have a through flow path having the same structure as the through flow path 200. When the through flow path is a groove formed on the surface of the bearing 31A, the through flow path extends parallel to the axial direction CL. When the through flow path is a through hole formed in the bearing 31A, the through flow path extends parallel to the axial direction CL.

As shown in FIG. 3, the second screw 4 includes a drainage hole 205 formed in the reduced diameter portion 4F of the second screw shaft 4A, and a drainage plug 206 for closing the drainage hole 205. .. As described above, by providing the bearing 30A having the through flow path 200, the invasion of sludge into the closed space SP1 is prevented. However, a part of the liquid contained in the sludge may enter the closed space SP1 through the through flow path 200. Therefore, the second screw 4 includes a drainage hole 205 and a drainage plug 206.

The drain hole 205 is arranged in the region between the bearing 30A and the bearing 31A. When draining the liquid that has entered the closed space SP1, the operator operates the second rotation mechanism 20 so that the drain hole 205 is arranged at the lowermost portion of the reduced diameter portion 4F. After that, the operator removes the drain plug 206 to discharge the liquid to the outside of the screw press through the drain hole 205. Rust is prevented from occurring by periodically draining the liquid through the drain hole 205. As a result, the internal space of the screw press can be kept clean.

In one embodiment, the operator may inject a lubricating liquid for lubricating the bearing 30A and the bearing 31A into the closed space SP1 through the drainage hole 205. By injecting the lubricating liquid and closing the drain plug 206, the closed space SP1 is filled with the lubricating liquid.

FIG. 7 is a diagram showing a lubricating liquid injection hole 209 formed in the reduced diameter portion 4F of the second screw shaft 4A and an injection plug 210 for closing the lubricating liquid injection hole 209. As shown in FIG. 7, the second screw 4 includes a lubricating liquid injection hole 209 formed in the reduced diameter portion 4F of the second screw shaft 4A, and an injection plug 210 for closing the lubricating liquid injection hole 209. May be good.

In the embodiment shown in FIG. 7, the drainage holes 205 and the lubricating liquid injection holes 209 are arranged at equal intervals along the circumferential direction of the reduced diameter portion 4F, but the drainage holes 205 and the lubricating liquid injection holes 209 are arranged at equal intervals. The arrangement of is not limited to the embodiment shown in FIG. In one embodiment, the drainage hole 205 and the lubricating liquid injection hole 209 may be arranged so as to be adjacent to each other along the circumferential direction of the reduced diameter portion 4F. In another embodiment, the drain hole 205 and the lubricating fluid injection hole 209 may be arranged adjacent to each other along the axial CL.

FIG. 8 is a diagram showing a pressure detecting device that detects the internal pressure of the closed space SP1. As shown in FIG. 8, the screw press may further include a pressure detection device 220 that detects the internal pressure of the closed space SP1. The pressure detection device 220 is arranged in the closed space SP1 and is electrically connected to the control unit 6. With such a configuration, the control unit 6 can monitor the internal pressure of the closed space SP1.

The above-described embodiment is described for the purpose of enabling a person having ordinary knowledge in the technical field to which the present invention belongs to carry out the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is construed in the broadest range according to the technical idea defined by the claims.

1 Screen casing 1A Dehydration area 1B Plug formation area 2 Input port 3 1st screw 3A 1st screw shaft 3B 1st screw blade 3C Reduced diameter part 3C-1 Tip 3D wall surface 4 2nd screw 4A 2nd screw shaft 4B 2nd screw Blade 4C Inner wall 4D Wall surface 4E End wall 4F Reduced diameter part 4F-1 Outermost end 6 Control unit 7 1st rotation mechanism 8 Blocking wall 10 Water sealing device 11, 12 Bearing 14 1st drive machine 15, 16 Sprocket 17 Chain 20 No. 2 rotation mechanism 22,23 Bearing 24 2nd drive 25,26 Sprocket 27 Chain 30,31 Slide bearing 30A, 31A Bearing 30A-1 Outer surface 30A-2 Inner surface 33 Drainage chamber 38 Sewage receiver 39 Drain 200 Through flow path 200a No. 1 Flow path 200b 2nd flow path 200c 3rd flow path 201 Cylindrical part 201a End surface 202 Circular part 202a Peripheral part 202b Surface 205 Drainage hole 206 Drainage plug 209 Lubricant injection hole 210 Injection plug 220 Pressure detector CL Axis Direction SP1 Sealed space CH1 Squeezed flow path

Claims (6)

The filter tube into which the liquid content is charged and
In the filter tube, the first screw and the second screw, which are arranged concentrically with the filter tube and transfer the liquid-containing material in a predetermined transfer direction,
A bearing arranged between the first screw and the second screw is provided.
The second screw includes a second screw shaft having a recess into which the first screw shaft of the first screw is inserted.
A squeezing flow path through which the liquid-containing material is squeezed is formed between the filtration cylinder and the first screw shaft and the second screw shaft.
The bearing is a screw press having a closed space formed between the first screw shaft and the second screw shaft and a through flow path for communicating the squeezing flow path. The screw press according to claim 1, wherein the through flow path is a groove formed on the surface of the bearing. The screw press according to claim 1 or 2, wherein the through flow path is a through hole formed in the bearing. The second screw
The drainage hole formed in the second screw shaft and
The screw press according to any one of claims 1 to 3, further comprising a drain plug for closing the drain hole. The second screw
The lubricating liquid injection hole formed in the second screw shaft and
The screw press according to any one of claims 1 to 4, further comprising an injection plug for closing the lubricating liquid injection hole. The screw press according to any one of claims 1 to 5, wherein the screw press includes a pressure detecting device for detecting the internal pressure of the enclosed space.

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