JPH0746355Y2 - Centrifugal dehydrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a centrifugal dehydrator used for, for example, refining a resin for suspension polymerization, and more specifically, it is arranged horizontally. The present invention also relates to a so-called decanter type centrifugal dehydrator having a hollow screw conveyor rotating at high speed, a drum coaxially fitted on the screw conveyor, and a casing fitted on the drum.

(Prior Art) For refining a resin, for example, a decanter type centrifugal dehydrator is used. The decanter type centrifugal dehydrator has a screw conveyor having a hollow shaft center portion arranged horizontally, a drum concentrically fitted on the screw conveyor, and a casing further containing the drum. Have
Then, for example, the slurry in which the resin to be purified and water are mixed, is fed into the hollow shaft center of the screw conveyor, and is discharged from the shaft center to between the screw conveyor and the drum. It The screw conveyor and the drum are rotated at high speed in the same direction.
The rotation speed of the drum is slightly higher than that of the screw conveyor. The slurry is centrifuged by the rotation of the screw conveyor and the drum at a slightly higher speed than the screw conveyor, and the resin, which is solid particles, is collected so as to be close to the peripheral wall of the drum fitted onto the screw conveyor, Due to the relative rotational speed difference with the screw conveyor, the resin is sequentially moved to one end of the drum. Then, it is discharged into the discharge chamber of the casing from a discharge port formed in the peripheral wall portion at one end of the drum.

The water separated from the slurry is moved in the direction opposite to the resin moving direction by the drum, and is discharged into the casing through the discharge port formed on the end surface of the drum end.

The resin discharged to the discharge chamber in the casing is made into a slurry by being mixed with washing water in the discharge chamber at the end of the casing, and falls into the discharge chamber downward to take out a discharge port provided below the discharge chamber. Taken from.

Thus, in the decanter type centrifugal dehydrator used for resin refining, the screw conveyor and the drum rotate at high speed, while the casing is in a fixed state.
In order to hold the drum in the casing so as to rotate at high speed with respect to the fixed casing, a support shaft 91a of the drum 91 is provided from the end face of the casing 92 to the end face as shown in FIG. It is inserted so as to have a slight gap with the insertion hole and is rotatably supported outside the casing 92.

(Problems to be Solved by the Invention) As described above, one end of the casing 92 is the discharge chamber 92a in which the centrifugally separated resin is mixed with washing water to form a slurry. Therefore, when the resin discharged from the peripheral wall of the drum 91 is mixed with the cleaning water and falls into a slurry, a part of the slurry leaks from the gap between the end surface of the casing 92 and the support shaft 91a of the drum. May occur.

For this reason, as shown in FIG. 5, a rotary disc 93 is attached to the drum support shaft 91a between the end face of the drum 91 and the end face of the casing 92 so as to rotate integrally with the drum support shaft 91a. . The slurry falling in the discharge chamber 92a collides with the rotating disc 93, and is radially spun by the centrifugal force of the rotating disc 93 rotating at a high speed.
The amount of slurry leaking from the gap between 91a and the end surface of casing 92 is reduced. However, with such a rotating disk 93, it is not possible to completely prevent the slurry from leaking from the gap between the drum support shaft 91a and the end surface of the casing 92, and between the rotating disk 93 and the end surface of the casing 92. The falling slurry leaks from the gap between the drum support shaft and the casing end surface. The slurry leaked from the casing 92 is melted by coming into contact with the drum support shaft 91a, and the molten resin is
There is a risk that the drum support shaft 91a may enter the bearing that supports the drum support shaft 91a and become unrotatable. The washed resin may be contaminated by the molten resin flowing into the discharge chamber 92a.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide a centrifugal dehydrator that can reliably prevent the centrifugally separated solid particles from leaking from the casing.

(Means for Solving the Problems) The centrifugal dehydrator of the present invention is a screw conveyor in which the slurry flowing into a horizontally arranged high-speed rotating screw conveyor is coaxially fitted onto the screw conveyor. Is a centrifugal dehydrator for centrifuging in a drum rotating at a high speed with a slight speed difference and extracting fixed particles from one end of the drum into a casing fitted onto the drum. Between the end face of the drum end portion and the casing end face opposite to the end face, the rotary disc mounted so as to rotate integrally with the support shaft of the drum, and a semi-cylinder covering the upper part of the rotary disc. And a cover in the form of a strip, which achieves the above-mentioned object.

(Embodiment) An embodiment of the present invention will be described below.

The centrifugal dehydrator of the present invention, as shown in FIG. 1, has a cylindrical drum 20 disposed in a casing 10 so that the axial direction is horizontal. The upper part of the casing 10 is the drum
It has a semi-cylindrical shape along the upper peripheral surface of 20. The drum 20 is in the shape of a truncated cone whose diameter gradually decreases as one end becomes closer to the end face side, and hollow support shafts 21a and 21b are provided on each end face of the drum 20 so as to project therefrom. . A support shaft 21a connected to the truncated cone-shaped end of the drum 20
Are extended to the outside of the casing 10 and are rotatably supported by the bearing 41. The support shaft 21a is inserted through the bearing 41, and a pulley 22 is attached to an end portion of the support shaft 21a. Rotation of the pulley 22 is transmitted to the support shaft 21a to rotate the drum 20 at a high speed. The other support shaft 21b also extends outside the casing 10 and is supported by the bearing 42. The support shaft 21b is
It is inserted through the bearing 42 and is connected to a gear box 43. Power is transmitted from the gear box 43 through the support shaft 21b to a rotary shaft 44 described later, and the screw conveyor 30 described later rotates at high speed. To be done.

Inside the drum 20, a screw conveyor 30 is arranged coaxially with the drum 20. The screw conveyor 30 has a hollow shaft center portion 31 and a blade body 32 spirally attached to the outer peripheral surface of the shaft center portion 31. One end of the shaft center portion 31 is attached to a rotary shaft 44 that is inserted through the support shaft 21b connected to the gear box 43,
The rotating shaft 44 is connected to the gear box 43. Each end of the shaft center portion 31 is rotatably supported in each end of the drum 20.

The screw conveyor 30 and the drum 20 are respectively rotating in the same direction at high speed, and the rotation speed of the drum 20 is slightly higher than the rotation speed of the screw conveyor 30, for example, the rotation speed of the drum 20 is 4000r. .pm, and the rotation speed of the screw conveyor 30 is 3976r.pm.

Support shaft 21a of the drum 20 to which the pulley 22 is attached
A slurry supply pipe 50 is inserted inside. A slurry, which is a mixture of resin and water, is supplied into the slurry supply pipe 50. The tip of the slurry supply pipe 50 is connected to the drum 20.
It is located in the middle of the shaft center portion 31 of the screw conveyor 30 by inserting the support shaft 21a thereof, and the supplied slurry is discharged from the tip portion. The slurry discharged from the tip of the slurry supply pipe 50 is discharged between the screw conveyor 30 and the drum 20 from a slurry discharge port 31a formed in a shaft center 31 of the screw conveyor 30.

The slurry discharged between the drum 20 and the screw conveyor 30 is centrifuged by the drum 20 and the screw conveyor 30 which are rotating at high speed, and the resin having a larger specific gravity than water is moved to the peripheral wall side of the drum 20. The water having a small specific gravity moves to the outer peripheral surface side of the shaft center portion 31 of the screw conveyor 30. The resin moved to the side of the peripheral wall in the drum 20 moves the inner peripheral surface of the drum 20 to the first side by the blade body 32 of the screw conveyor 30 rotating slightly slower than the drum 20.
As indicated by an arrow A in the figure, the drum 20 is moved along the inner peripheral surface of the drum 20 to the frustoconical end portion.

The water separated from the slurry is moved in a direction opposite to the moving direction of the resin, and the casing 10 is discharged from a plurality of drainage ports 27 formed at the end surface of the drum 20 on the moving direction of the water.
Is discharged inside. Each drainage port 27 is formed on a circle centered on the axis of the drum 20, and the flow rate of water discharged from each drainage port 27 can be changed by changing the diameter of this circle. The water discharged from each drainage port 27 is discharged from a moisture discharge port 61 provided at the end portion of the casing 10 and projecting downward.

At a position close to the end surface of the truncated cone-shaped end portion of the drum 20, a large number of resin discharge ports 24 through which the resin moved along the inner peripheral surface of the drum 20 by the blade body 32 of the screw conveyor 30 is circulated. It has been opened. Each resin outlet 24
Are provided over the entire circumference in a state where adjacent ones are spaced from each other at an appropriate distance. And drum 20
The resin moved along the inner peripheral surface passes through the resin discharge port 24 and is discharged from the drum 20 into the casing 10. The resin discharge port 24 of the drum 20 is located in the discharge chamber 12 partitioned by the partition wall 11 at the end of the casing 10.

In the discharge chamber 12 of the casing 10, a water injection nozzle 14
(See FIG. 2) is provided. The water injection nozzle 14 is
The outer peripheral surface of the rotating drum 20 is horizontally arranged so as to face the portion that moves from the bottom to the top, and water is poured into the dehydrated resin discharged from the resin discharge port 24 of the drum 20 to Wash the resin with water.

Water discharged from the water injection nozzle 14 turns the resin into a slurry, and the resin outlet 62 is provided below the discharge chamber 12.
And the slurry is sent to the next step.

A support shaft 21 connected to a truncated cone-shaped end of the drum 20
A disk-shaped rotating disk 26 is attached to a so as to be located inside the discharge chamber 12 in the casing 10. The rotating disc 26 is adapted to rotate integrally with the support shaft 21a of the drum 20. As shown in FIG. 2, the support shaft 21a that rotates integrally with the drum 20 that rotates at a high speed has an end surface facing the partition wall 11 of the discharge chamber 12 in the casing 10 in the fixed state.
13 is inserted so that a slight gap is formed with the insertion hole. For this reason, the rotating disk 26 is provided in order to radially disperse the resin, which is discharged from the resin discharge port 24 of the drum 20 and is scattered toward the end surface 13 together with the water discharged from the water injection nozzle 14, by the centrifugal force. It is provided.

The upper part of the rotating disk 26 is covered with a semi-cylindrical cover 18. The cover 18 is attached to the end surface 13 of the discharge chamber 12 in the casing 10 by welding, for example. Normally, the cover 18 is mounted so that the left end in FIGS. 2 and 4 reaches above the right end of the rotating disk 26, and preferably, as shown in FIGS.
It is extended to the 20 side and is provided so as to surely cover the upper side of the rotating disc 26. Further, as shown in FIG. 3, it is preferable to surely cover the upper half of the support shaft 21a of the drum 20. Further, the cover 18 is arranged so as not to come into contact with the rotating disc 26, and is preferably spaced from the rotating disc 26 by about 5 mm. As in the present embodiment, when the support shaft 21a vicinity portion 13a of the drum 20 on the end surface 13 of the discharge chamber 12 is located inside the discharge chamber 12, the end surface 13 is covered so as to cover the vicinity portion 13a. You can attach it to.

The cover 18 is thus provided in the discharge chamber of the casing 10.
The structure is not limited to being attached to the end face 13 of 12, but may be attached to the lower end of the connecting plate 19 whose upper and side faces are attached to the upper and side faces of the casing 10 by welding or the like, as shown in FIG. . In this case, the connecting plate
19 is attached to the end face 13 side of the discharge chamber 12 in the cover 18, and the length from the edge of the cover 18 on the end face side of the drum 20 to the connecting plate 19 is about 15 to 20 mm, and the connecting plate 19 is transmitted. It is preferable that the water and the like fall along the upper surface of the cover 18. When the upper end of the connecting plate 19 is attached to the casing 10 by welding, front welding is preferable.

In the centrifugal dehydrator having such a configuration, as described above, the slurry supplied from the slurry supply pipe 50 is separated into resin and water, and the water is taken out from the water discharge port 61. On the other hand, the dehydrated resin is discharged from the resin discharge port 24 of the drum 20 into the discharge chamber 12 of the casing 10, washed with water discharged from the water injection nozzle 14 in the discharge chamber 12, It is discharged as a slurry from the resin outlet 62.

At this time, a part of the slurry poured into the resin discharged into the discharge chamber 12 collides with the inner peripheral surface of the casing 10 and is scattered toward the end surface 13 side of the discharge chamber 12. The support shaft 21a of the drum 20 rotating at high speed is inserted into the end surface 13 of the discharge chamber 12 in the casing 10, and a part of the slurry scatters toward the portion of the end surface 13 into which the support shaft 21a is inserted. . However, the slurry that drops from above toward the portion where the support shaft 21a is inserted falls along the upper surface of the cover 18, and the slurry that horizontally scatters toward the portion where the support shaft 21a is inserted is It collides with the rotating circular plate 26 and is ejected radially. As a result, the casing 10
There is no risk that the slurry will scatter in the portion of the end surface 13 where the support shaft 21a is inserted, and the slurry may leak out of the casing 10 through the gap between the insertion hole provided in the end surface 13 of the casing 10 and the support shaft 21a. There is no.

(Effect of the Invention) As described above, in the centrifugal dehydrator of the present invention, the gap between the support shaft supporting the drum and the end surface of the casing is covered by the rotating disc and the cover. Is
There is no risk of the solid particles that have been centrifuged being leaked. As a result, there is no risk that the solid particles will adhere to the support shaft that rotates at a high speed and obstruct the rotation of the support shaft, and the solid particles that have leaked from the discharge chamber will flow into the discharge chamber and the solid particles in the discharge chamber There is no risk of contaminating the particles.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of the centrifugal dehydrator of the present invention, FIG. 2 is a sectional view of a main portion thereof, FIG. 3 is a sectional view taken along line III-III of FIG. 2, and FIG. FIG. 5 is a sectional view of an essential part of another embodiment of the centrifugal dehydrator, and FIG. 5 is a sectional view of an essential part of the conventional centrifugal dehydrator. 10 ... Casing, 11 ... Partition, 12 ... Discharge chamber, 13 ... Casing end face, 18 ... Cover, 20 ... Drum, 21a, 21b ... Drum support shaft plug body, 24 ... Resin discharge port, 26 ... Rotating disc, 30 ... Screw conveyor.

Claims (1)

[Scope of utility model registration request] 1. A drum in which a slurry, which has flowed into a horizontally arranged high-speed rotating screw conveyor, is fitted onto the screw conveyor coaxially and rotates at a high speed with a slight speed difference from the screw conveyor. Is a centrifugal dehydrator for centrifuging at, and extracting solid particles from one end of the drum into a casing fitted onto the drum, wherein the end face of the drum end from which the solid particles are taken and the end face are opposed to each other. A centrifugal dehydrator comprising: a rotating disc mounted so as to rotate integrally with the supporting shaft of the drum between the casing end surface and a semi-cylindrical cover that covers the upper portion of the rotating disc.