JPH08294644A - Scraper device of centrifugal dehydrator - Google Patents

Abstract

PURPOSE: To bring scrapers close to the inner face of a screen and prevent the clogging of the screen by mounting the scrapers provided on a screw impeller blade movably in the radius direction, and attaching weight to the scrapers. CONSTITUTION: A screen 1a is stretched on the periphery of a cylindrical screen 1, and a screw shaft 2 is set concentrically in the inside thereof, and a screw impeller blade 2a is wound on the screw shaft 2 and fixed thereon. The outer peripheral section of the screw impeller blade 2 is brought close to the inner face of the screen 1a, and scrapers 3 are fitted on channels 4 on the peripheral face of the screw impeller blade 2a and set slightly movably in the radius direction of the screw impeller blade 2a. Protrusions are formed on the side face and engaged with the notches of the screw impeller blade 2a, and weights 5 are attached to the scrapers 3. The scrapers with weights are pressed to the inner face of the screen forcibly by centrifugal force to scrape cakes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a scraper device for a centrifugal dehydrator used for dehydrating sludge and the like.

[0002]

2. Description of the Related Art Conventionally, it is well known that a sewage sludge is dehydrated by a centrifugal dehydrator. That is, in this centrifugal dehydrator, sludge is supplied into a cylindrical screen that rotates at high speed, liquid content is passed through the screen to a saucer, and heavy solids are conveyed by screw blades that rotate in the cylindrical screen, and the machine is started from one end. I try to get it out.

[0003]

However, in the conventional device as described above, there is a problem that the contact portion is worn when the screw blade is constantly brought into contact with the inner surface of the screen cylinder. There is a clearance between them. For this reason, the solid material (cake) laminated on the inner surface of the screen cannot be completely conveyed, and the screen is clogged to deteriorate the filtration performance.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the gist thereof is to provide the outer peripheral surface of screw blades provided in the cylindrical screen of a centrifugal dehydrator. A scraper made of an elastic material such as rubber is loaded in the groove to make the scraper movable in the radial direction of the screw blades, and the scraper 3 is moved outward in the scraper or in the vicinity of the scraper by centrifugal force. A weight that can be moved is provided.

[0005]

Since the present invention is constructed as described above,
Sludge is supplied into the cylindrical screen, and when the cylindrical screen is rotated, the sludge is pressed against the inner surface of the cylindrical screen by the centrifugal force to be dehydrated, and the filtrate is taken out of the machine through the saucer, and the solid content (cake) is removed. Laminate on the inner surface of the cylindrical screen.

The laminated cakes can be conveyed by the screw blades rotating at the same time and taken out of the machine from one end of the cylindrical screen. In dewatering this sludge, in the present invention, the scraper made of an elastic material is movably inserted in the groove of the outer peripheral surface of the screw blade in the radial direction of the screw blade, and the weight is attached to the scraper. With the rotation of the screw blades, the scraper is pressed against the inner surface of the cylindrical screen, the cake to be laminated is scraped off, and the screen is prevented from being clogged, so that an efficient dewatering operation can be performed. Hereinafter, the present invention will be specifically described with reference to the drawings.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a vertical cross-sectional side view of a main part of a centrifugal dehydrator according to the present invention. In the drawing, reference numeral 1 is a cylindrical screen having a screen 1a stretched around its periphery, and 2 is its interior. It is a screw shaft that is supported concentrically with. Screw shaft 2
A screw blade 2a is fixedly wound around, and the outer peripheral portion of the screw blade 2a is brought close to the inner surface of the screen 1a, and a scraper 3 is attached to the peripheral surface portion.

The scraper 3 is made of rubber or the like in the shape of a cord, and has a groove 4 formed on the peripheral surface of the screw blade 2a.
The screw blade 2a can be slightly moved in the radial direction, and the lengthwise direction of the screw blade 2a is provided with a protrusion 3a, which is engaged with a notch provided in the screw blade 2a to be displaced. I try not to. (Fig. 2
(See Fig. 5)

A weight 5 is attached to the scraper 3 so as to enhance the centrifugal effect. In the one shown in FIGS. 3 and 4, a string-shaped weight 5 made of lead or the like is embedded. The weight 5 may be provided behind the scraper 3 in the groove 4 for fitting the scraper 3 as shown in FIG.

FIGS. 6 to 8 show an example of a concrete structure of the scraper, FIG. 6 shows an example in which the long scraper 3 is divided and manufactured, and FIG. 7 shows a circular shape. 8C shows a point where a notch 3C is provided on the inner peripheral side in order to
Shows a manufacturing method in which the scraper 3 is divided into two pieces in the vertical direction and the weight 5 is sandwiched and bonded.

In FIG. 1, arrow A indicates the supply sludge,
S is a cake, 6 is a cover of the cylindrical screen 1, 7 is a filtrate tray, 8 is a cake discharge pipe, and 9 is a drive motor.

The apparatus according to the present invention is constructed as described above, and the sludge (a) supplied into the cylindrical screen 1 is
As the cylindrical screen 1 is rotated, it is pressed against the screen 1a, its water (filtrate) falls through the screen 1a to the filtrate tray 7, and the solid content (cake) is laminated on the inner surface of the screen 1a. At this time, the cylindrical screen 1
Is conveyed along the inner surface of the screen 1a by the screw blade 2a which rotates with a slight rotation difference, and is taken out of the machine from the discharge pipe 8.

In the sludge dewatering operation, in the apparatus according to the present invention, the scraper 3 is attached to the screw blade 2a so as to be movable in the radial direction thereof, and the weight 5 is attached thereto. Is strongly pressed against the inner surface of the screen 1a as it rotates, and the cake S to be laminated is scraped off and screw blades 2a
It can be conveyed toward the discharge section.

That is, in the conventional dehydrator of this type, when the screw blades are brought into sliding contact with the inner surface of the screen, there is a problem such as abrasion of the screen and the screen blades, and a clearance is provided between them, so that the screen 1a is provided.
According to the present invention, the scraper 3 with the weight 5 is strongly pressed against the inner surface of the screen 1a by the centrifugal force to scrape the cake. It is possible to keep the screen 1a clean at all times without abrasion of the screw blades, and perform highly efficient dehydration work.

While the scraper 3 may be worn during the above-mentioned operation, the scraper 3 according to the present invention is
Since it moves with respect to the screw blades 2a, it is more relaxed and more durable against wear than a fixed scraper. Even when it is worn, it is only necessary to replace the scraper 3, and the replacement work is not fixed, which is extremely easy.

In addition, there is a concern that the cake may enter the groove 4 shown in FIGS. 3 and 9 during the above-described operation, but as shown in FIG. 10, a ridge 3b is provided on the side surface of the scraper 3. By setting, it is possible to prevent the infiltration of the cake and reduce the resistance when the scraper 3 moves, which is effective.

[0017]

As described above, according to the present invention, in the dehydrator for sludge and the like utilizing centrifugal force, the scraper provided on the screw blade is mounted movably in the radial direction of the screw blade, and the scraper is provided with a weight. Therefore, the scraper is brought into close contact with the inner surface of the screen to prevent the screen from being clogged so that the dehydration work can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional side view of an apparatus according to the present invention.

FIG. 2 is a cross-sectional view taken along the line XX of FIG.

FIG. 3 is a schematic cross-sectional view of a mounting portion of the scraper according to the present invention.

FIG. 4 is likewise a plan view of a part of the scraper in an attached state.

FIG. 5 is likewise a side view of a part of the scraper in an attached state.

FIG. 6 is likewise a plan view of the scraper.

FIG. 7 is likewise a side view of the scraper.

FIG. 8 is likewise a cross-sectional view of the scraper.

FIG. 9 is likewise a schematic cross-sectional view of another example of a state where the scraper is attached.

FIG. 10 is a partial perspective view of another example of the scraper.

[Explanation of symbols]

 1 Cylindrical screen 2a Screw blade 3 Scraper 4 Groove 5 Weight

Claims (1)

[Claims] 1. A scraper 3 made of an elastic material such as rubber is mounted in a groove 4 provided on an outer peripheral surface of a screw blade 2a provided in a cylindrical screen 1 of a centrifugal dehydrator, and the scraper 3 is attached to the screw blade 2a. The scraper 3 is made movable in the radial direction, and the scraper 3 is generated in the scraper 3 or in the vicinity of the scraper 3 by centrifugal force.
A scraper device for a centrifugal dehydrator provided with a weight that can move the outside.