JP2519460B2 - Screw press type press - Google Patents

Description

TECHNICAL FIELD The present invention relates to a screw press-type press suitable for use in, for example, dehydration treatment of activated sludge or human waste, squeezing or dehydration of food or feed, and the like. is there.

(Prior Art) Conventionally, in this type of screw press type squeezing machine, as shown in, for example, FIG. , The outer cylinder (32) consisting of a perforated plate-shaped screen member, the machine stand (33)
Is horizontally disposed toward one end side of the outer cylinder (32), a cake outlet (34) is provided at the end of the outer cylinder (32), and a conveying screw (35) is mounted in the outer cylinder (32). The rotating shaft (36) of the carrying screw (35) is linked to a motor (37) provided at the other end of the machine base (33). Also the rotary shaft (36)
Is formed in a conical shape having a larger diameter toward the cake outlet (34) side, and the rotary blade (38) of the conveying screw (35) is substantially in sliding contact with the outer cylinder (32). The transfer space (39) formed between the outer cylinder (32) and the rotating shaft (36) is partitioned by the rotor blades (38), and the transfer space (39)
The radial cross-sectional area of is gradually reduced toward the cake outlet (34). Then, the motor (37) drives and rotates the conveying screw (35) to convey the substance to be squeezed to the cake outlet (34), and gradually pressurizes the substance to be squeezed while passing through the narrower conveying space (39). The squeezed liquid squeezed by the pressurization is discharged from the screen of the outer cylinder (32), and the cake solidified after squeezing is sequentially discharged from the cake outlet (34).

Further, the object to be squeezed is gradually solidified as the squeezing progresses, and is pressed against the outer cylinder (32) with a strong pressure while rotating, so that the screen member constituting the outer cylinder (32) withstands the squeezing pressure, and It must be a material that is unlikely to cause clogging due to impurities contained in the material to be squeezed. To meet this requirement, conventionally, as shown in FIG. 7, for example, as shown in FIG. A double structure having an outer layer plate (41) having a large number of large-diameter punching holes formed thereon is stacked on top of the outer layer plate (41). In the outer cylinder (32) using the screen member having such a structure, The squeezed liquid generated at the time of pressing is discharged to the outside through the mesh of the thin and fine inner layer plate (40), and the pressing pressure is thick and has high strength.
I try to accept it in 1).

(Problems to be Solved by the Invention) By the way, in the above-described conventional configuration, the mesh of the inner layer plate (40) is made slightly larger, or the area ratio of the mesh to the entire inner layer plate (40) is designed to be large. Although it is possible to prevent clogging by doing so, on the other hand, if this is done, the squeezing pressure cannot be increased, and the required dehydration treatment and squeezing treatment cannot be performed,
Therefore, there is a limit to how large the mesh size and the occupied area ratio can be designed. Therefore, in the conventional configuration, the foreign matter to be squeezed is strongly pressed against the outer cylinder (32) to easily cause clogging.

Also, if the screen member is composed of a mesh, foreign matter is caught on the opening peripheral edge of the mesh regardless of whether the object to be squeezed is fed in the circumferential direction or the axial direction by the rotation of the conveying screw, resulting in extra clogging. However, there is a problem that high dewatering performance or squeezing performance cannot be obtained due to the combination of these disadvantages.

The present invention has been made in order to solve the above conventional problems, and by adding a device to the configuration of the screen member that constitutes the outer cylinder, it is possible to obtain a high degree of dehydration performance or squeezing performance. The purpose of the present invention is to provide a screw press type press that hardly causes clogging.

(Means for Solving the Problems) The technical means of the present invention for achieving such an object is to fix the outer cylinder in a position-fixed state between the inlet of the object to be squeezed and the cake outlet. The inner cylinder is rotatably arranged in the outer cylinder, and screw screw blades that are substantially in sliding contact with the outer cylinder are fixed along the axial direction of the inner cylinder. The diameters of the outer cylinder and the inner cylinder are relatively changed so that the radial cross-sectional area of the conveyance space of the object to be squeezed formed between the inner cylinder and the inner cylinder gradually becomes smaller as it approaches the cake outlet. The cylinder is constituted by a screen member in which a large number of strips having a substantially triangular cross section are arranged in parallel and a slit-like gap is provided between the strips, the slits having a narrow inner peripheral surface side and a wide outer peripheral surface side. It has features.

(Operation) According to the above configuration, the object to be squeezed in from the input port is gradually squeezed while being conveyed in the cake outlet direction in the conveying space by the driving rotation of the screw rotary blades, and the squeezed liquid generated in this squeezing process. Is discharged from the gap of the outer cylinder screen to the outside, and the cake of the squeezed product that has solidified in the transfer space is sequentially discharged from the cake outlet.

In this squeezing process, the inner peripheral surface of the outer cylinder has a narrow gap and a wide pressure receiving surface, and since each strip has a triangular shape and has high strength in the pressure receiving direction, a high squeezing pressure is applied to the object to be squeezed. The advanced dewatering zone can obtain the squeezing performance. In addition, the foreign matter in the object to be squeezed into the narrow gap has a slit-like relationship in the gap, and therefore, in the direction of either the circumferential direction or the axial feeding direction due to the rotation of the screw rotor. On the other hand, the foreign matter in the material to be pressed enters the gap without being caught by the opening edge, and after entering the gap, the gap expands to the outside, so that it does not stay and is quickly discharged to the outside. Therefore, the clogging of the outer cylinder screen can be prevented.

(Example) Hereinafter, the Example of this invention is described in detail based on drawing. 1 to 5 show a screw press type squeezing machine according to this embodiment, and in FIGS. 1 to 3,
(1) is a horizontally stationary machine base, and a hopper (2) as an input port for the material to be squeezed is erected on one end side of the machine base (1), and the machine is operated from this hopper (2). The outer cylinder (3) is arranged substantially horizontally and fixedly in a position toward the other end of the table (1), and the inner cylinder (4) is coaxially and rotatably arranged in the outer cylinder (3). However, a cake outlet (5) is provided between the other ends of the inner cylinder (4) and the outer cylinder (3). This inner cylinder (4)
Is one that penetrates through the hopper (2), one end of which is interlocked with the first motor (6) having a large output, and is rotationally driven in the direction of arrow (a) in FIG. The equally divided central part is formed into a conical shape that expands toward the other end of the machine base (1), and the small diameter shaft part (4b) is provided on both sides of this conical part (4a).
And a large-diameter cylindrical portion (4c) are connected to each other, and the large-diameter cylindrical portion (4c) is formed by a screen member (S) through which a squeezed liquid generated by squeezing an object to be squeezed is passed. The conical portion (4a) and the small diameter shaft portion (4b) are formed by a blind plate that does not pass the squeezing liquid.

The outer cylinder (3) is entirely composed of a screen member (S), and has a large size from one end facing the hopper outlet (2a) to an intermediate portion located on the large diameter end of the conical portion (4a). Formed into a cylindrical shape with a large diameter, and the portion (3b) from the large diameter cylindrical portion (3a) to the end of the large diameter cylindrical portion (4c) of the inner cylinder (4) is directed toward the cake outlet (5) side. It is shaped like a conical cone. Therefore, between the outer cylinder (3) and the inner cylinder (4), a transfer space (where the radial cross-sectional area is maximum on the hopper outlet (2a) side and gradually decreases toward the cake outlet (5) side ( 7) is formed, and the screw rotor (8) fixed to the inner cylinder (4) by welding or the like is arranged over the space from the transfer space (7) to the hopper (2). is there.

This screw rotary blade (8) rotates in a state of being substantially in sliding contact with the inner peripheral surface of the outer cylinder (3) by the driving rotation of the inner cylinder (4), and the spiral action thereof causes the compressed object introduced from the hopper (2). The object is conveyed toward the cake outlet (5) side while rotating the object in the rotating direction. Then, by the screw rotor (8), the transfer space (7)
Are divided into a plurality of transfer chambers (7a) that gradually narrow toward the cake outlet (5), and the objects to be squeezed are gradually conveyed in the process of transferring the objects to be squeezed to the narrower transfer chamber (7a). Pressurized dehydration, and the squeezed liquid squeezed by this is the outer cylinder (3).
Is discharged to the outside through the screen of the inner cylinder, and flows into the inner cylinder through the screen of the inner cylinder large diameter cylindrical part (4c),
The cake produced by this pressing is discharged from the cake outlet (5) to the outside.

The above-mentioned configuration of the outer cylinder (3) and the inner cylinder (4) is such that the radial cross-sectional area of each transfer chamber (7a) becomes smaller as it approaches the cake outlet (5). It is sufficient that the diameter of 4) is relatively changed, for example, the outer cylinder (3) is a cylindrical shape with a constant diameter, and the inner cylinder (4) is continuously directed toward the cake outlet (5) side. It may be a conical shape that expands.

By the way, a vacuum suction device (9) for discharging the squeezed liquid accumulated inside to the outside by vacuum suction is incorporated in the large diameter cylindrical portion (4c) of the inner cylinder. This vacuum suction device (9) has a partition wall (11) separating one end of a suction pipe (10) provided on the axis of the large-diameter cylindrical portion (4c) between the conical portion (4a) and the large-diameter cylindrical portion (4c). Is welded to the one end to hermetically close the opening at one end, and the other end of the suction pipe (10) is connected to the machine base (1).
While being airtightly and rotatably attached to the intake passage of the vacuum pump (12) installed at the other end of the, the suction pipe (10) and the large-diameter cylindrical portion (4c) as shown in the longitudinal sectional view of FIG. The partition wall (13) divides the closed space formed between the walls into a plurality (four in the figure) in the radial direction, and the partition wall (14) divides the closed space into a plurality (two in the figure) in the axial direction. A guide pipe (16) which is divided to form a required number of liquid storage chambers (15) into which the squeezed liquid enters and which communicates with each liquid storage chamber (15).
Has a structure in which the suction pipe (10) is exposed.
In FIG. 1, (17) is a vacuum gauge provided in the suction passage of the vacuum pump (12), and (18) is a flow rate adjusting valve provided in the discharge passage of the vacuum pump (12).

In the vacuum suction device (9), the suction pipe (10) rotates in the direction of the arrow (a) together with the inner cylinder (4) during the operation of the compressor, and accordingly, the squeezed liquid is collected from all directions in each liquid reservoir. Enter the room (15). Since each of the liquid storage chambers (15) also rotates in the same direction as the suction pipe (10), the squeezed liquid that has penetrated into the liquid storage chambers (15) does not stay in the liquid storage chambers (15) and the guide pipe (16) Through the suction pipe (1
It is sucked into the inside of the vacuum pump (0) and further discharged from the discharge passage of the vacuum pump (12) to the outside.

A device other than the vacuum suction device may be used as a device for discharging the squeezed liquid retained in the inner cylinder (4) to the outside.

On the other hand, the cake outlet (5) is provided with an automatic discharge pressure adjusting device (19) for keeping the discharge pressure of the cake constant or arbitrarily adjusting it.

Conventionally, a means for adjusting the discharge pressure is provided with a lid plate that closes the cake outlet, and the lid plate is urged toward the cake outlet by a spring having a predetermined spring pressure so that the cake in the transfer chamber facing the outlet is spring-loaded. Although it is proposed that the cake discharge pressure is discharged to the outside against the biasing force of the spring, the cake discharge pressure is given by the spring pressure of the spring, so that arbitrary adjustment is impossible.

Therefore, as shown in FIG. 3, the automatic discharge pressure adjusting device (19) according to the present embodiment has a rotary drum (20) having a cylindrical portion having substantially the same diameter as the large diameter cylindrical portion (4c) of the inner cylinder (4). Is butt-opposed to the end of the large-diameter cylindrical portion (4c) in a butt-like manner, and is rotatably supported on the suction pipe (10) via a bearing (21), and on the rotary drum (20). The screw rotor (2) having a screw shape opposite to the screw rotor (8) is formed.
2) is fixed by welding or the like, while the rotating drum (2
0) is interlocked with a second motor (23) having a small output provided on the other end side of the machine base (1), and the second motor (23) reverses the direction of rotation of the inner cylinder (4). The cake discharged from the cake outlet (5) is scraped off by the rotating blades (22) by rotating in the direction of the arrow (b) in FIG. 1, and further, the transfer chamber near the cake outlet (5). A diaphragm type pressure gauge (24) for measuring the cake internal pressure is provided in the portion (7a), a second motor (23) is electrically linked to the pressure gauge (24), and the second motor (23) is also provided. By using an inverter pressure adjusting motor as described above, the rotation speed of the rotating drum (20) can be arbitrarily adjusted, thereby adjusting the discharge pressure of the cake.

In the vicinity of the cake outlet (5), the end of the large-diameter cylindrical portion (4c) of the inner cylinder is formed with a required size, for example, about 50 mm by a blind plate, and the end of the outer cylinder (3) around the rotary drum (20). Similarly, the blind plate is also used to prevent the squeezed liquid reaching the cake outlet (5) from returning to the inside of the cake.

According to the above configuration, the objects to be squeezed continuously from the hopper (2) are successively transported to the transport space (7) by the screw rotor (8), and the transport chamber (7a) around the small diameter shaft portion (4b). Then, it receives a weak squeezing pressure, then reaches the cone (4a) and is gradually squeezed at a high pressure. In the pressing process up to the conical portion (4a), the cake remaining in the transfer chamber (7a) after pressing has not yet been solidified, so that the squeezed liquid is exclusively passed through the screen of the outer cylinder (3) to the outside. Is discharged to.

However, after this, when the object to be pressed reaches the narrow transfer chamber (7a) around the large-diameter cylindrical portion (4c), the pressing pressure applied to the object to be pressed becomes a considerably high pressure, so that the cake is solidified. Remarkable. Now, for example, if the entire inner cylinder (4) is formed by a blind plate, a solid layer is generated in the surface layer portion of the object to be squeezed in the transfer chamber (7a), and is generated in the transfer chamber (7a). The squeezing liquid is not discharged through the screen due to the presence of the solid layer and reaches the cake outlet (5) while remaining as water bubbles in the transfer chamber (7a), and the cake released from the squeezing pressure at the cake outlet (5). Since the water bubbles return inside, the dewatering or squeezing performance is significantly reduced.

On the other hand, in this embodiment, the squeezed liquid generated in the inner layer of the cake is sucked from the screen of the inner cylinder (4) through the suction pipe (10).
As it is discharged to the outside after passing through, the generation of water bubbles is suppressed,
The dehydration effect is remarkably improved.

In the squeezing machine of this embodiment configured as described above,
The entire outer cylinder (3) and the large diameter cylindrical portion (4) of the inner cylinder (4)
The screen member (S) constituting c) and has the following structure.

That is, as shown in FIG. 4 and FIG. 5, each screen member (S) is provided with a large number of stainless steel strips (25) having a cross section of an isosceles triangle with a required gap (t). The strips (25) are arranged in parallel with each other, and the strips (25) are displaced in a slanted state in this parallel state, and in the state where this displacement posture is maintained, the strips (25) are attached to the tips of the strips (25). (twenty five)
A connecting strip material (26a) or (26b) in the form of water drops or a flat plate arranged substantially orthogonal to the above is integrally welded.

In this way, a slit-shaped gap (t) having a fan-shaped cross section that is narrow on the bottom side of each strip (25) and wide on its tip side is formed on each strip (25).
When the outer cylinder (3) is composed of the screen member (S) which is just like a cage and is interposed therebetween, each strip (2
With the bottom surface of 5) being the inner peripheral surface side, the strip (25) and the gap (t) are substantially along the axial direction, and moreover, the rotation direction when the object to be squeezed is conveyed, that is, the screw rotary blade (8). The stepped arrangement configuration in which the opening side edge of the gap (t), which is on the front side in the rotation direction of, protrudes toward the transport space (7) with a step h from the opposing side edge adjacent to this side edge. I am doing it.
Further, when the screen member (S) is used for the outer cylinder (3), the connecting strip (26) arranged on the outer peripheral surface of the outer cylinder (3).
For a), a water droplet-shaped cross section is used.

On the other hand, when the inner cylinder (4) is composed of the screen member (S), the strip (25) and the gap (t) are substantially circular with the bottom surface of each strip (25) being the outer peripheral surface. Cake outlet (5) along the circumferential direction and at the time of conveying the material to be squeezed
The opening side edge of the gap (t), which is the front side in the transport direction to the side,
The stepped arrangement configuration is provided such that it has a step h more than the opposing side edge adjacent to this side edge and projects toward the transport space (7). When the screen member (S) is used for the inner cylinder (4), the connecting strip (26b) arranged on the inner peripheral surface of the inner cylinder (4) has a flat plate cross section as shown in FIG. Is used.

In addition, the dimensions of each part of the screen member (S) are as follows:
Width w of the bottom surface is 2.5 to 3.0 mm, and the transfer space (7) has a gap (t).
The narrowest part facing the x = 0.1 to 0.5 mm, step h = 0.2 to 0.5
mm, the width y of the water-drop-shaped connecting strip (26a) is about 8.0 mm, and the width z of the flat plate-like connecting strip (26b) is about 3.0 mm.

In the compressor having the outer cylinder (3) and the inner cylinder (4) configured by using the screen member (S) as described above, the outer cylinder (3) and the inner cylinder large diameter cylindrical portion ( Both peripheral surfaces facing the transfer space (7) of 4c) have a narrow opening of the gap (t) and a wide pressure receiving surface, and each strip (25) has a triangular shape and has a large strength in the pressure receiving direction. It is possible to apply high-pressure pressing pressure to the object to be pressed to perform strong dehydration or pressing.

Further, the foreign matter in the object to be compressed that has entered the opening of the narrow gap (t) enters without being caught by the opening edge of the slit-shaped gap (t) due to the spiral action of the screw rotor (8). That is, in this case, due to the presence of the step h, the foreign matter in the object to be compressed pressed against the outer cylinder (3) and the inner cylinder (4) is not caught on the opening edge of the gap (t),
It smoothly enters the gap (t), and after entering the gap (t), it quickly exits from the gap (t) that spreads in a fan shape without staying at all.

In forming the screen member (S), the strips (25) are arranged so that the bottom surfaces thereof are flat, and a step h is formed between the opposite opening edges of the gap (t) between the strips (25). Even if it is not provided, it can be used without clogging depending on the type of object to be pressed or the application of the press.

(Effects of the Invention) As described above, according to the present invention, a large number of strips each having a substantially triangular cross section are arranged in parallel, and slits having a narrow inner peripheral surface side and a wide outer peripheral surface side are provided between the respective strips. Since the outer cylinder is configured by the screen member having the gaps, the inner peripheral surface of the outer cylinder has a narrow gap and a wide pressure receiving surface in the compression process, and each strip has a triangular shape. Since the strength in the pressure receiving direction is large, a high pressing pressure can be applied to the object to be pressed, and high dewatering or pressing performance can be obtained. In addition, the foreign matter in the object to be squeezed that has entered the narrow gap is liable to move in either the circumferential direction or the axial feeding direction due to the rotation of the screw rotor due to the relation that the gap is a slit line. On the other hand, the foreign matter in the material to be pressed enters the gap without being caught by the opening edge, and after entering the gap, the gap expands to the outside, so that it does not stay and is quickly discharged to the outside. Therefore, it is possible to reliably prevent the occurrence of clogging of the outer cylinder screen, and to realize a high degree of dehydration performance or compression performance.

[Brief description of drawings]

1 to 5 show an embodiment of a screw press type compressor according to the present invention. FIG. 1 is a vertical sectional side view showing the entire structure, and FIG. 2 is a cutting line II- in FIG. Fig. 3 is an enlarged cross-sectional view along II, Fig. 3 is an enlarged cross-sectional view of the III part in Fig. 1, Fig. 4 is a partially enlarged vertical front view of the outer cylinder, and Fig. 5 is a partially enlarged vertical side face of the inner cylinder and the outer cylinder. It is a figure. 6 and 7
The drawing shows a conventional example, FIG. 6 is a partially cutaway side view, and FIG. 7 is a partially enlarged sectional view of an outer cylinder. (2) …… Inlet (hopper), (3) …… Outer cylinder,
(4) …… Inner cylinder, (5) …… Cake outlet, (7) …… Transport space, (8) …… Screw rotor, (25) …… Strip material, (S) …… Screen member, ( t) ... gap,
(H) …… Step.

Claims (4)

(57) [Claims] 1. An outer cylinder (3) is fixedly disposed between the inlet (2) of the object to be squeezed and the cake outlet (5), and the inside of the outer cylinder (3) is fixed. The cylinder (4) is rotatably arranged, and the screw rotor (8) which is in sliding contact with the outer cylinder (3) is fixed along the axial direction of the inner cylinder (4), and the outer cylinder (4) is fixed. The outer cylinder (3) is such that the radial cross-sectional area of the space (7) for conveying the material to be compressed formed between the cylinder (3) and the inner cylinder (4) becomes gradually smaller as it approaches the cake outlet (5). ) And the diameter of the inner cylinder (4) are relatively changed,
The outer cylinder (3) has a slit-like shape in which a large number of strips (25) having a substantially triangular cross section are arranged in parallel and the inner peripheral surface side is narrow and the outer peripheral surface side is wide between the respective strips (25). A screw press type compressor characterized by comprising a screen member (S) provided with a gap (t). 2. A plurality of strips (25) having a substantially triangular cross section are arranged in parallel in the inner cylinder (4), and the strips (25) are arranged in parallel.
The screw press type compressor according to claim 1, comprising a screen member (S) having a gap (t) between which an inner peripheral surface side is wide and an outer peripheral surface side is narrow. 3. The step (h) at the front opening side edge of the gap (t) in the conveying direction of the squeezed object is higher than the side edge adjacent to this side edge.
Claim 1 wherein the peripheral surface of each strip (25) facing the transfer space (7) is inclined stepwise so as to project toward the transfer space (7). The screw press-type press described in item 2. 4. The screw press type compressor according to claim 2, wherein the squeezed liquid accumulated in the inner cylinder (4) is discharged to the outside.