JP7216886B2 - screw press - Google Patents

Description

In the present invention, by rotatably connecting straight screw shafts divided in the axial direction and decreasing the number of revolutions of each connected shaft unit toward the sludge discharge side, the sludge transport speed is reduced. It relates to a screw press characterized by a gradual decline toward the rear stage of the chamber.

Conventionally, a screw press has a cylindrical screen with a filtering surface suspended between a front frame and a rear frame that are erected on a frame, and a tapered screw shaft with spiral screw blades wound around the screen. commonly known.

In addition, the taper type screw shaft is divided into two in the axial direction, and the concentration zone and the filtration/dehydration zone of the filtration chamber formed between the two divided screw shafts and the screen are arranged so that they can rotate independently. A screw press provided is disclosed in U.S. Pat.

Patent Document 2 discloses a screw press in which a straight screw shaft around which screw blades are wound is provided inside a screen, and the pitch of the screw blades decreases toward the downstream side of the screw shaft. disclosed.

Japanese Patent No. 3775232 Japanese Patent No. 4465384

Conventionally, the screw shaft of a screw press has a tapered configuration, and the sludge supplied to the starting end side of the filtration chamber formed between the screen and the screen is conveyed toward the other end of the screw shaft by the screw blades and compressed. Along with this, the screen separates moisture.
The sludge conveyed to the other end of the screw shaft is pressed by a presser facing the discharge port, and then discharged from the discharge port. At this time, the sludge is pressed not only by the presser, but also by the change in volume of the filtration chamber formed between the tapered screw shaft and the screen, so that consolidation progresses.
In this way, in conventional screw presses, a tapered screw shaft is used to apply pressure to the sludge being conveyed. Since it is necessary to increase it toward the side and it takes time and effort to process it, it takes a lot of time and money to manufacture.

Further, in the screw press of Patent Document 1, a tapered screw shaft divided into two in the axial direction is rotatably arranged in the concentration zone and the filtration/dehydration zone of the filtration chamber, and the rotation speed of the screw shaft is adjusted in each zone. By individually setting, the number of times of sliding contact between the screen and the scraper attached to the tip of the screw blade can be adjusted for each zone.
However, in order to rotate the divided screw shafts individually, a driving device must be provided for each of the divided screw shafts, which requires many power sources. As a result, extra equipment costs, running costs, and the like are required.
In addition, since the plurality of split surfaces formed on the split tapered screw shaft have different shaft diameters, when the split surfaces are connected, a step occurs on the split surfaces and the workpiece leaks through the gap. In addition, it is necessary to provide a seal member having a different diameter for each divided surface, and there is also the problem that it takes time and effort to process the seal.

Furthermore, in the screw press of Patent Document 2, a straight-body screw shaft around which screw blades are wound is provided inside a screen, and the pitch of the blades is made smaller toward the downstream. Since the volume of the filtration chamber formed between is constant, it is not possible to apply a pressing force to the sludge due to the volume change. In order to apply a pressing force to the sludge, the pitch of the blades is made smaller toward the downstream side of the screw shaft.
In addition, by gradually decreasing the impeller pitch toward the downstream of the screw shaft, the transport speed of the sludge becomes slower toward the rear stage of the filtration chamber, causing the sludge to accumulate and the screw shaft and the screen to rotate together. ing.

The present invention has been made in view of the above-mentioned problems. Straight screw shafts divided in the axial direction are rotatably connected, and the rotation speed of each connected shaft unit is decreased toward the sludge discharge side. This is a screw press that reduces the transport speed of sludge toward the rear stage of the filtration chamber to improve the dewaterability of the cake.

The present invention relates to a screw press having a straight-body type screw shaft, in which a plurality of shaft units obtained by dividing the screw shaft are inserted into the screw shaft, one end of which is connected to a driving machine, and the other end of which is rotatably supported. An input shaft, an output shaft inserted into a screw shaft and supported at both ends, an input gear fixed to the input shaft and arranged in each shaft unit so that the diameter becomes smaller toward the discharge side, and the output shaft rotates. Equipped with an output gear that can be inserted freely and meshed with each input gear, and a ring gear that is provided on the inner peripheral surface of each shaft unit and meshes with the output gear, so that the rotation speed of the screw shaft decreases toward the discharge side. do. As a result, the transport speed of the sludge decreases and the sludge stays in the rear stage of the filtration chamber, and the retained sludge is pushed backward by the fast-transported sludge transported from the front stage of the filtration chamber, thereby promoting consolidation. Dehydration of the cake can be enhanced.

By integrating multiple gears with different diameters into a multi-stage output gear, power from the input gear can be transmitted to the ring gear.

By forming the convex fitting portion or concave fitting portion having the seal member on the side surface of the shaft unit, each shaft unit can smoothly slide and rotate via the seal member when connected.

As described above, in the present invention, the screw shaft is divided into respective shaft units, and the number of revolutions of each shaft unit is decreased toward the discharge side. Moisture content of the cake is reduced. Since the sludge is transported at a high speed in the front stage of the filtration chamber, the sludge supplied from the beginning side can be efficiently transported to the end side, so that the amount of sludge to be treated can be increased. In addition, since the screw shaft is a straight body type, there is no need to change the shaft diameter from the starting end side to the terminal end side. do not have. Furthermore, since each shaft unit is rotated by the gears provided on the common input shaft and output shaft, only one power source is required, and extra equipment costs and running costs are not incurred.

It is a longitudinal side view of a screw press according to the present invention. 1 is a longitudinal side view of a split screw shaft according to the present invention; FIG. FIG. 10 is a vertical cross-sectional view and a vertical side view of a fifth axis unit according to the present invention; FIG. 5A is a vertical cross-sectional view and a vertical cross-sectional side view of a fourth axis unit according to the present invention;

FIG. 1 is a longitudinal side view of a screw press according to the present invention.
Reference numeral 1 denotes a screw press, in which a cylindrical screen 10 having a filtering surface is supported by a front frame 7 and a rear frame 8 erected on a frame 9 .
A straight screw shaft 2 around which spiral screw blades 3 are wound is arranged inside the screen 10 , and a filtration chamber 4 is formed between the screw shaft 2 and the screen 10 .
A hopper 5 for supplying sludge is provided at the upper part of the starting end side of the screen 10 , and the sludge supplied from the hopper 5 into the filtration chamber 4 is separated from water by the screen 10 and is passed through the screw blades 3 . It is conveyed to the end side of the screen 10 while being pressed by the conveying force. Then, it is discharged after being compressed by being pressed by the presser 6 provided opposite to the discharge port located on the terminal side.

A straight body type screw shaft 2 around which screw blades 3 are wound is a split screw shaft 2 divided in the axial direction, and a plurality of divided shaft units are rotatably connected to each other.
In each shaft unit, the screw blades 3 and the screw shaft 2 are divided in the direction perpendicular to the rotating shaft for each pitch of the screw blades 3 . When the shaft unit around which one pitch of the screw blades 3 is wound makes one rotation, the sludge is conveyed by the screw blades 3 by one pitch, that is, from one end to the other end of the shaft unit.

FIG. 2 is a longitudinal side view of a split screw shaft according to the present invention.
In this embodiment, the split screw shaft 2 is formed by rotatably connecting five straight screw shafts 2 divided in the axial direction, and the five shaft units constituting the split screw shaft 2 are: A first axis unit 2a, a second axis unit 2b, a third axis unit 2c, a fourth axis unit 2d, and a fifth axis unit 2e are arranged from one end to the other end.
A seal member 25 is attached to the connecting surface of the connected shaft units so that the shaft units can slide and rotate relative to each other via the seal member 25 .

An input shaft 12 is inserted through the connected screw shaft 2 in parallel with the axis. An input gear 14 corresponding to each shaft unit is fitted on the input shaft 12, and the input gear 14 can be a power transmission means such as a spur gear or a helical gear.
One end of the input shaft 12 is connected to the driving machine 11, and when the driving machine 11 is driven, the input gear 14 fixed to the input shaft 12 is rotated. The other end of the input shaft 12 is rotatably supported by a frame or a bearing provided on the screw shaft 2 .

An output shaft 13 is inserted through the screw shaft 2 in parallel with the input shaft 12 . The output shaft 13 is rotatably provided with output gears 15 that mesh with the respective input gears 14 , and the output gears 15 rotate according to the rotation of the input gears 14 . Both ends of the output shaft 13 are supported by the front frame 7 and the rear frame 8 .

A ring gear 22 that meshes with the output gear 15 is provided on the inner peripheral surface of each shaft unit, and the rotation of the ring gear 22 rotates each shaft unit.
Specifically, after the input gear 14 is rotated by the driving device 11 , the output gear 15 rotates while meshing with the input gear 14 . Since the ring gear 22 rotates while meshing with the output gear 15, the power of the input gear 14 is transmitted to the ring gear 22 via the output gear 15, and each shaft unit rotates.

If the output gear 15 cannot fit between the input gear 14 and the ring gear 22 due to the gear ratio, a multi-stage gear 16 in which two or more gears with different diameters are arranged side by side and integrated can be provided as the output gear 15. good.
In this embodiment, the output gear 15 is arranged between the input gear 14 and the ring gear 22 provided in the fifth shaft unit 2e, and the shaft units from the first shaft unit 2a to the fourth shaft unit 2d are arranged. A multistage gear 16 is arranged between an input gear 14 and a ring gear 22 provided respectively. The arranged output gear 15 and multistage gear 16 are meshed with the input gear 14 and the ring gear 22 .

In this embodiment, the input gear 14 is arranged in each shaft unit so that the diameter gradually decreases from the first shaft unit 2a toward the fifth shaft unit 2e. With such a configuration, the output gear 15 (or the multi-stage gear 16) and the ring gear 22 corresponding to each input gear 14 have a rotation speed that decreases from the first shaft unit 2a toward the fifth shaft unit 2e. Power is transmitted to In other words, each shaft unit that is rotatably connected reduces the rotational speed toward the discharge side.
Note that the number of divisions of the screw shaft, the pitch of the blades, and the like may be appropriately changed according to the design conditions.

FIG. 3 is a vertical sectional view and a vertical side view of the fifth axis unit.
The fifth shaft unit 2e is a shaft unit provided at the other end of the split screw shaft 2 divided into five in the axial direction. An input shaft 12 is inserted through the fifth shaft unit 2e in parallel with the axis, and an input gear 14 having continuous outer peripheral teeth is fixed to the input shaft 12. As shown in FIG. An output shaft 13 is passed through the inside in parallel with the input shaft 12, and an output gear 15 having continuous outer peripheral teeth is passed through the output shaft 13 so as to be rotatable. The output gear 15 is provided so as to mesh with the input gear 14 and rotates while meshing with the input gear 14 .
Further, a ring gear 22 having continuous inner peripheral teeth is provided on the inner peripheral surface of the fifth shaft unit 2e so that it can rotate while meshing with the output gear 15. As shown in FIG.
When the input gear 14 is rotated by the driving machine 11 , the output gear 15 rotates while meshing with the input gear 14 , and the ring gear 22 rotates while meshing with the output gear 15 . That is, by rotating the input gear 14, the power of the input gear is transmitted to the ring gear 22 via the output gear 15, and the ring gear 22 rotates. Since the ring gear 22 is provided on the inner peripheral surface of the fifth shaft unit 2e, rotation of the ring gear 22 means rotation of the fifth shaft unit 2e. Therefore, the rotation speed of the fifth shaft unit 2e can be adjusted by changing the rotation speed of the driving machine 11 and the diameter of the input gear .

A convex fitting portion 23 is formed at one end of the fifth shaft unit 2e as a connection surface with the adjacent fourth shaft unit 2d. The convex fitting portion 23 has a cylindrical shape protruding in the axial direction, and has a seal member 25 such as an O-ring attached to its outer peripheral surface.
By inserting the convex fitting portion 23 of the fifth shaft unit 2e into the concave fitting portion 24 formed at the other end of the fourth shaft unit 2d, the respective shaft units slide against each other via the seal member 25. can be rotated.

4A and 4B are a vertical cross-sectional view and a vertical cross-sectional side view of the fourth shaft unit.
The fourth axis unit 2d is an axis unit adjacent to the upstream side of the fifth axis unit 2e. Similar to the fifth shaft unit 2e, the input shaft 12 is inserted parallel to the shaft center inside the shaft unit, and the input gear 14 is fixed to the input shaft 12. As shown in FIG. Also, the output shaft 13 is inserted parallel to the input shaft 12 .
Here, in order to set the rotational speed of the shaft unit so that the rotational speed of the shaft unit decreases toward the discharge side, the diameter of the input gear 14 of the fourth shaft unit 2d located upstream is made larger than that of the fifth shaft unit 2e. It is necessary to increase the number of revolutions of the fourth shaft unit 2d to be higher than that of the fifth shaft unit 2e. Along with this, it is necessary to make the diameter of the output gear 15 of the fourth shaft unit 2d smaller than that of the fifth shaft unit 2e.
Therefore, in the fourth shaft unit 2d, as the output gear 15, a multi-stage gear 16 in which two or more gears with different diameters are arranged in parallel and integrated is rotatably inserted through the output shaft 13. As shown in FIG. As a result, the input gear 14 and the ring gear 22 can be meshed with each other, so that the power of the input gear 14 can be transmitted to the ring gear 22 .
In this way, when the output gear 15 cannot fit between the input gear 14 and the ring gear 22 due to the gear ratio relationship, by providing the multi-stage gear 16 as the output gear 15, the power of the input gear 14 is transmitted to the ring gear 22. A shaft unit that transmits and has a ring gear 22 on its inner circumference rotates.

One end of the fourth shaft unit 2d is formed with a convex fitting portion 23 having a seal member 25 attached to its peripheral surface. Insert into recessed fitting 24 . Further, the other end of the fourth shaft unit 2d is formed with a concave fitting portion 24 that is a connection surface with a convex fitting portion 23 formed on the adjacent fifth shaft unit 2e. The concave fitting portion 24 is recessed in the axial direction in a cylindrical shape for inserting the cylindrical convex fitting portion 23 .
Each shaft unit is formed with a convex fitting portion 23, a concave fitting portion 24, or both, and when the shaft units are connected, the convex fitting portion 23 having a seal member 25 formed on one of the shaft units is By inserting into the recessed fitting portion 24 formed in the other shaft unit, each shaft unit can slide and rotate with respect to each other via the seal member 25 .
In addition, the configuration of the fitting portion is not limited to this as long as the adjacent shaft units can slide and rotate with each other. Furthermore, the diameter, shape, etc. of the gear can be set as appropriate.

The third shaft unit 2c, the second shaft unit 2b, and the first shaft unit 2a, which constitute the split screw shaft 2, are provided with an input gear 14 and an output gear 15, respectively, similarly to the fourth shaft unit 2d. A multistage gear 16 is provided as the output gear 15 .
Also, in order to reduce the rotation speed of the shaft units toward the discharge side, the diameter of the input gear 14 is maximized in the first shaft unit 2a and gradually decreased toward the fifth shaft unit 2e. Conversely, the diameter of the output gear 15 is the smallest in the first shaft unit 2a, and gradually increases toward the fifth shaft unit 2e.

The operation of the screw press in this embodiment will be described in detail.
Sludge is supplied from a hopper 5 provided at the top of the screen 10 on the starting end side. The supplied sludge is separated from moisture by the screen 10 and conveyed toward the second shaft unit 2b by the rotation of the screw blades 3 of the first shaft unit 2a.
The volume of the sludge conveyed to the second shaft unit 2b has decreased due to the solid-liquid separation action in the first shaft unit 2a, but the conveying speed of the second shaft unit 2b is the same as the conveying speed of the first shaft unit 2a. Since the sludge is slower, the retention time is longer, and the sludge is brought in from the first shaft unit 2a, which has a higher transport speed, so that the sludge is compacted and the dehydration efficiency is improved.
The volume of the sludge conveyed to the third shaft unit 2c has decreased due to the solid-liquid separation action of the second shaft unit 2b, but the conveying speed of the third shaft unit 2c is the same as the conveying speed of the second shaft unit 2b. Since the sludge is slower, the retention time is longer, and the sludge is brought in from the second shaft unit 2b, which has a higher transport speed, so that the sludge is compacted and the dehydration efficiency is improved.
The volume of the sludge conveyed to the fourth shaft unit 2d has decreased due to the solid-liquid separation action of the third shaft unit 2c, but the conveying speed of the fourth shaft unit 2d is the same as the conveying speed of the third shaft unit 2c. Since the sludge is slower, the retention time is longer, and the sludge is brought in from the third axis unit 2c, which has a higher transport speed, so that the sludge is compacted and the dehydration efficiency is improved.
Since the fifth axis unit 2e conveys sludge at a slower speed than the fourth axis unit 2d, dehydration efficiency is improved by bringing in sludge from the fourth axis unit 2d, which has a faster conveying speed, and consolidating the sludge with the presser 6 at the discharge port. improves. Thereafter, the dehydrated cake having a low moisture content is discharged from the discharge port.
By setting the number of rotations of the rotatably connected shaft units to decrease from the first shaft unit 2a toward the fifth shaft unit 2e, the sludge transport speed increases toward the discharge side. descend. The sludge in the rear stage of the filter chamber 4, which is conveyed at a slow speed, is pressed and compacted by the sludge conveyed from the front stage of the filter chamber 4, which is conveyed at a high speed.

A screw press according to the present invention comprises shaft units formed by axially dividing a straight-body type screw shaft and rotatably connecting them. By making the screw shaft splittable, if the screw blades or screw shaft need to be replaced due to wear or damage, only the necessary shaft unit can be removed, reducing the trouble of repairing or replacing it. can.
In addition, since the sludge transport speed can be adjusted by setting the number of revolutions for each shaft unit, it is possible to handle all kinds of sludge with different properties.

2 screw shaft 11 driver 12 input shaft 13 output shaft 14 input gear 15 output gear 22 ring gear 16 multistage gear 25 sealing member 23 convex fitting portion 24 concave fitting portion

Claims (3)

In a screw press having a straight body type screw shaft 2,
a plurality of shaft units obtained by dividing the screw shaft 2;
an input shaft 12 that is inserted into the screw shaft 2, has one end connected to the driving machine 11, and has the other end rotatably supported;
an output shaft 13 inserted into the screw shaft 2 and supported at both ends;
an input gear 14 fixed to the input shaft 12 and arranged in each shaft unit so that the diameter becomes smaller toward the discharge side;
an output gear 15 rotatably inserted through the output shaft 13 and meshing with each input gear 14;
a ring gear 22 provided on the inner peripheral surface of each shaft unit and meshing with the output gear 15;
with
A screw press characterized by: 2. A screw press according to claim 1, wherein said output gear 15 is a multistage gear 16 in which a plurality of gears having different diameters are integrated. 3. The screw press according to claim 1, wherein a convex fitting portion 23 or a concave fitting portion 24 having a seal member 25 is formed on a side surface of the shaft unit.

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