JPH0671491A - Screw type dehydrating machine - Google Patents

Abstract

PURPOSE:To constitute the above machine in such a manner that the entire part of a ribbon-shaped screw is nearly uniformly heated to a prescribed temp., materials to be dehydrated are compressed by the ribbon-shaped screw and can be simultaneously heated, by which the dehydration rate is additionally improved. CONSTITUTION:The ribbon-shaped screw 4 is freely rotatably disposed within the annular space 3 between an inside cylinder 1 and outside cylinder 2 which are disposed concentrically. The materials 8 which are to be dehydrated and are charged from a charge port 9 provided on the root end side of the outside cylinder 2 into the annular space 3 are compressed and dehydrated by rotationally driving the ribbon-shaped screw 4. The water generated by the dehydration is drained via drain screens 7, 16 formed on both inside and outside cylinders 1, 2. The dehydrated materials 8 are discharged via a discharge port 10 provided on the front end side of the outside cylinder 2. Flow passages 21 for heating fluid are formed within the ribbon-shaped screw 4 over the overall length thereof.

Description

Detailed Description of the Invention

[0001]

The present invention relates to construction sludge, bottom sludge,
The present invention relates to a screw type dehydrator for compressing and dehydrating sludge such as sewage, night soil or pulp.

[0002]

2. Description of the Related Art Conventionally, as a dehydrator, there are a filter press, a belt press, and the like. These are for removing water contained in sludge by simply squeezing the sludge. Therefore, there is a certain limit to dehydration. Therefore, it is possible to improve the dehydration rate by squeezing sludge and heating it at the same time, but it is structurally extremely difficult to incorporate heating means into them in the above-mentioned filter press, etc. I can't.

On the other hand, as an example of a screw type dehydrator incorporating a heating means, a screw with a shaft is rotatably arranged in a cylindrical casing having a drainage screen, and the screw with a shaft is rotatably driven to form a casing. At the same time as pressing and dehydrating the sludge put in, heating fluid such as steam is circulated in the screw shaft to heat the sludge,
There are some that try to improve the dehydration rate.

[0004]

In the above-mentioned conventional screw type dehydrator, the contact area between the sludge and the screw shaft is small, and the sludge can be heated only partially, so that the dehydration rate is greatly improved. In addition, the sludge adheres to the screw and a so-called entrainment phenomenon easily occurs, and it is difficult to squeeze the sludge in a predetermined manner.

In view of the above-mentioned drawbacks, an object of the present invention is to provide a screw type dehydrator capable of further improving the dehydration rate and preventing the so-called entrainment phenomenon of sludge from occurring.

[0006]

To achieve the above object, the present invention rotatably disposes a ribbon-shaped screw in an annular space between an inner cylinder and an outer cylinder that are concentrically arranged. By rotating and driving the ribbon-shaped screw, the dehydrated substance put into the annular space is squeezed and dehydrated from an input port provided on the proximal end side of the outer cylinder, and the dehydrated water is removed from the inner and outer cylinders. In the dehydrator configured to drain outside through a drainage screen formed in one or both of the above, and to discharge the dehydrated substance to be dehydrated outside through a discharge port provided on the tip side of the outer cylinder, A flow passage for the heating fluid is formed in the ribbon screw over its entire length.

[0007]

According to the above construction, after the substance to be dehydrated such as sludge is charged into the annular space between the inner and outer cylinders from the charging port, the screw is rotated to squeeze and dehydrate the substance to be dehydrated. be able to. Then, the dehydrated water is drained to the outside through a drainage screen formed in one or both of the inner and outer cylinders, and the dehydrated substance is discharged to the outside from a discharge port provided on the tip side of the outer cylinder. To be done. Further, by supplying a heating fluid such as steam to the flow passage in the screw at the same time as the squeezing, the squeezed product to be dehydrated can be entirely heated to further improve the dehydration rate.

[0008]

1 and 2 show a screw type dehydrator according to an embodiment of the present invention, in which an inner cylinder 1 and an outer cylinder 2 are shown.
And a ribbon-shaped screw 4 rotatably disposed in an annular space 3 formed between the inner and outer cylinders 1 and 2.

The outer cylinder 2 has an outer cylinder main body 2a formed in a taper shape toward the front end side, and a proximal end side cylinder fixed concentrically to the proximal end and the distal end of the outer cylinder main body 2a. Part 2
b and the distal end side cylinder portion 2c, the support frame 6 is provided on the base 5.
It is fixed through 6. Then, the outer cylinder body 2a
Is formed with a drainage screen 7 having a large number of drainage holes 7a, and a feed hopper (feeding port) for feeding a substance 8 to be dehydrated such as sludge into the annular space 3 in the base end side cylinder portion 2b. 9 is integrally projectingly provided, and a discharge port 10 for discharging the dehydrated dehydrated material 8 to the outside is formed in the front end opening portion of the front end side cylinder portion 2c. A water receiving tank (not shown) is provided below the outer cylinder 2.

The tip of the inner cylinder 1 is the discharge port 1 described above.
A rotary wheel that protrudes outward from 0, is fixed to the base 5 via a support frame 11, and the base end portion thereof is rotatably disposed in the base end side tubular portion 2b via a bearing 12. 1
It is arranged concentrically with the outer cylinder 2 by being inserted into a recess 14 formed in the center of the inner surface of the bearing 3 via a bearing 15. Further, a drainage screen 16 composed of a large number of drainage holes 16a is formed in a central portion of the inner cylinder 1 facing the outer cylinder body 2a. It should be noted that in FIG. 1, reference numerals 17 and 18 denote seal members interposed between the proximal end side cylinder portion 2b and the rotary wheel 13 and between the rotary wheel 13 and the inner cylinder 1.

The tip end of the ribbon-shaped screw 4 extends to the vicinity of the discharge port 10, and the base end of the ribbon-shaped screw 4 is fixed to the rotary wheel 13 and is keyed to the outer peripheral surface of the rotary wheel 13. Sprocket wheel 1
A drive source (not shown) linked to 9 is rotationally driven.

Further, as shown in FIG. 3, the ribbon-shaped screw 4 has a rectangular box-shaped cross section, and the internal closed space extends over substantially the entire length of the ribbon-shaped screw 4 at the center of the space. The partition plate 20 thus arranged forms a flow passage 21 composed of an outward passage 21a on the outer peripheral side and a return passage 21b on the inner peripheral side. The forward passage 21a and the return passage 21b communicate with each other at their tip portions and Rotating wheel 1 at the base end
3 is a rotary joint 2 fitted externally to the communicating holes 22 and 23 and the outer surface protruding portion 13a of the rotary wheel 13.
Heating fluid supply pipe 26 through the annular grooves 24a and 24b of No. 4
, And the heating fluid discharge pipe 27, respectively. As shown in FIG. 4, the heating fluid such as steam supplied to the outward path 21 a through the heating fluid supply pipe 26 and the communication hole 22 is supplied to the ribbon-shaped screw 4. Return path 2 after reaching the tip
1b and returns to the base end portion of the ribbon-shaped screw 4 and is discharged to the outside through the communication hole 23 and the heating fluid discharge pipe 27, whereby the entire ribbon-shaped screw 4 is discharged. It is designed to be heated to a predetermined temperature almost uniformly. In FIG. 1, 28 is a rotating wheel 13.
The seal member is interposed between the rotary joint 24 and the rotary joint 24.

Further, as shown in FIG. 1, a cone valve 29 is slidably fitted onto the tip of the inner cylinder 1, and a cylinder device is arranged between the cone valve 29 and the support frame 11. At 30, the cone valve 29 is moved toward and away from the discharge port 10 to appropriately adjust the opening area of the discharge port 10 so that the dehydrated product 8 can be squeezed with a desired squeezing force.

Explaining the procedure of squeezing and dehydrating, first, a heating fluid is circulated through the flow passage 21 in the ribbon-shaped screw 4 to heat the ribbon-shaped screw 4 to a predetermined temperature, and the material 8 to be dehydrated is introduced into the hopper. Throw in 9. As a result, the substance to be dehydrated 8 is pushed out toward the discharge port 10 in the annular space 3 by the rotating ribbon-shaped screw 4 and is also squeezed and dehydrated, and the dehydrated water is discharged inside and outside through the drainage screens 7 and 16. The water 8 is drained to the outside of the cylinders 1 and 2, and the dehydrated substance 8 is discharged to the outside from the discharge port 10. In this case, the contact area between the article to be dehydrated 8 and the ribbon-shaped screw 4 is large, and the article to be dehydrated 8 is heated to a predetermined temperature substantially evenly during squeezing and dehydrating, so that the dehydration rate is further improved as compared with the conventional case. be able to. Further, the water in the portion of the dehydrated product 8 that comes into contact with the ribbon-shaped screw 4 is evaporated by heating, and the friction between the dehydrated product 8 and the ribbon-shaped screw 4 is reduced. Since the phenomenon is prevented, the squeezing rate can be further improved as compared with the conventional one. Furthermore, by heating the substance to be dehydrated 8, the dehydrating action of the dehydration auxiliary agent mixed in the substance to be dehydrated 8 is also improved.

In the above structure, the ribbon-shaped screw 4 is formed in a rectangular box shape in cross section, and the partition plate 20 is arranged in the closed space to form the flow passage 21, but the invention is not limited to this. Instead, for example, as shown in FIG. 5, a heating fluid circulation pipe 32 may be provided in the closed space, or, as shown in FIG. 6, the ribbon-shaped screw 4 is formed of a plate material 33. A pair of ridges 34, 34 may integrally be provided on the side surface of the plate member 33 along the longitudinal direction thereof, and the heating fluid distribution pipe 35 may be provided on each ridge 34, 34. Further, as shown in FIG. 7, the ribbon-shaped screw 4 is formed by a plate member 36, and a side plate 38 is arranged between a pair of projecting ridges 37, 37 integrally formed on the upper and lower side edge portions of the plate member 36. Installed between the side plate 38 and the plate member 36. By disposing the partition plates 39 in the center portion of the made a sealed space, may be formed a flow path 21 of the heating fluid.

In the above embodiment, the inner and outer cylinders 1 and 2 are fixed, and only the ribbon screw 4 is rotationally driven. However, both or one of the inner and outer cylinders 1 and 2 is not referred to as the ribbon screw 4. You may make it rotate separately. According to this, the shearing resistance of the article to be dehydrated 8 is increased, and the pressing dehydration can be performed more effectively.

Although the drainage screens 7 and 16 are formed on both the inner and outer cylinders 1 and 2, the drainage screens (7 or 16) may be formed on only one of them.

[0018]

According to the present invention, a heating fluid flow passage is formed over the entire length of a ribbon-shaped screw for squeezing and dehydrating a substance to be dehydrated, and the entire ribbon-shaped screw is heated to a predetermined temperature. Since it is heated almost uniformly, the ribbon-shaped screw can squeeze and heat the material to be dehydrated at the same time, and the dehydration rate can be further improved as compared with the conventional case.

Further, the moisture in the portion of the dehydrated material that comes into contact with the ribbon-shaped screw is evaporated by heating, and the friction between the dehydrated material and the ribbon-shaped screw is reduced, so that the so-called entrainment phenomenon of the dehydrated material is prevented. Therefore, the squeezing rate can be further improved compared to the conventional case.

Further, by heating the substance to be dehydrated, it is possible to enhance the dehydrating action of the dehydration auxiliary agent mixed therein.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a screw type dehydrator which is an embodiment of the present invention.

FIG. 2 is a view on arrow AA of FIG.

FIG. 3 is a cross-sectional view of the ribbon screw.

FIG. 4 is a schematic explanatory view of a heating fluid flow passage formed in the ribbon screw.

FIG. 5 is a transverse cross-sectional view of a main part showing a modified example of the ribbon screw.

FIG. 6 is a transverse cross-sectional view of a main part showing another modified example of the ribbon screw.

FIG. 7 is a transverse cross-sectional view of a main part showing still another modified example of the same ribbon-shaped screw.

[Explanation of symbols]

 1 Inner Cylinder 2 Outer Cylinder 3 Annular Space 4 Ribbon Screw 7 Drain Screen 8 Dehydrated Material 9 Input Hopper (Input Port) 10 Discharge Port 16 Drain Screen 21 Flow Channel

Claims (1)

[Claims] 1. A ribbon-shaped screw is rotatably arranged in an annular space between an inner cylinder and an outer cylinder, which are concentrically arranged, and the ribbon-shaped screw is rotatably driven. The material to be dehydrated introduced into the annular space from the inlet provided on the proximal side is squeezed and dehydrated, and the dehydrated water is drained to the outside through a drainage screen formed on one or both of the inner and outer tubes. In addition, in the dehydrator configured to discharge the dehydrated material to the outside through the discharge port provided on the tip side of the outer cylinder, in the ribbon screw, a heating fluid flow passage is provided over its entire length. A screw type dehydrator characterized by being formed.