JPS6313797Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a sludge centrifugal concentrator for concentrating slurry such as sludge using centrifugal filtration.

The filtration device of a centrifugal thickener, which is most widely used for thickening sludge, consists of a rotating basket that has a truncated conical inner surface with an open bottom and a large number of through holes formed in the peripheral wall, and The slurry introduced into the cloth is moved from the small diameter side to the large diameter side due to the action of centrifugal force, and water is absorbed into the cloth and the rotating basket. It is concentrated by being removed through the pores. Therefore, the fabric comes into contact with the rotating basket on its outer surface and the slurry on its inner surface, and is subjected to forces in various directions between the two, which may cause wrinkles and deformation, or the fabric may become deformed. or cause damage. In order to overcome these drawbacks, cloth is glued or welded to the rotating basket, but this requires a lot of work when replacing the cloth, and it is not easy to attach it without wrinkles. .

The purpose of this invention is to provide an improved sludge centrifugal thickening device that securely fixes the cloth to the rotating basket, allows for easy removal when replacing the cloth, and significantly extends the useful life of the cloth. It is said that

Next, an embodiment of this invention will be described with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 indicates a rotating basket, and reference numeral 2 indicates a cloth.
The rotating basket 1 has a truncated conical inner surface with an open bottom, and has a number of through holes 1a formed in its peripheral wall, and is fixed to a rotating shaft 4 by a mounting portion 3 provided at one end thereof. ing. Also cloth 2
forms a truncated cone shape that coincides with the inner surface of the rotating basket 1, and is fixed to the rotating basket 1 at the center and the periphery.

The means for fixing the cloth 2 to the rotating basket 1 at its center includes a disk-shaped presser plate 5 and this presser plate 5.
and a fixing bolt 6 which clamps the center of the cloth 1 between the rotating basket 1 by pressing the cloth 1 against the center of the rotating basket 1. Further, a pair of positioning pins 7 are implanted in the presser plate 5, and each positioning pin 7 inserts into a positioning hole 8 provided in the rotating basket 1, thereby attaching the cloth 2 and the presser plate to the rotating basket 1. 5. Regulates the mounting position. It is preferable that the cloth 2 has a reinforcing patch at the center where it contacts the presser plate 5 etc., and the presser plate 5 is attached to the rotating basket 1 so that the presser plate 5 does not strongly contact only a part of the cloth 2. Preferably, the inner surface of the cone has a smaller diameter than the frustoconical top surface forming it.

Furthermore, in order to fix the fabric 2 to the rotating basket 1 at its peripheral edge, a plurality of attachment pins 9 are used which penetrate the fabric 2 and project into the attachment holes of the rotating basket 1. This mounting pin 9 is, for example, a third
As shown in the figure, it consists of a head 9a and legs 9b whose tips are divided into a plurality of parts, and is preferably constructed by integral molding of a synthetic resin having appropriate elasticity such as polyethylene. As shown in detail in FIG. 4, this attachment pin 9 passes through a through hole formed in the peripheral edge of the cloth 2 and is inserted into an attachment hole 10 provided in the rotating basket 1. The diameter of the mounting hole 10 is smaller than the maximum diameter of the leg 9b, so when the leg 9b is inserted into the mounting hole 10, the leg 9b
shrinks due to its own elasticity, and its restoring force closes the mounting hole 10.
is held in place by pressing against the inner surface of the In this state, the cloth 2 is sandwiched between the inner surface of the rotating basket 2 and the head 9a of the attachment pin 9, and is held in this position. Also, mounting hole 1
0 may be a long hole having a width slightly smaller than the diameter of the leg 9b of the mounting pin 9 and extending from the short diameter side to the long diameter side of the rotating basket 1.

As shown in an enlarged view in FIG. 5, the through hole 1a formed in the rotating basket 1 has a substantially circular cross-sectional shape, and the inner end thereof is directed toward the tip, that is, the inner surface of the rotating basket 1. It forms a curved surface whose diameter gradually increases. During centrifugal concentration, the rotating basket 1, the cloth 2, and the slurry introduced therein are rotated at high speed, and due to the centrifugal force at this time, the cloth 2 is strongly pressed against the inner surface of the rotating basket 1, and the cloth 2 is tightly pressed into the through hole 1a. The facing portions receive a force that pushes them into the through hole 1a. However, since the inner end of the through hole 1a forms a curved surface, the cloth 2 only curves gently along this curved surface, as shown in FIG. 6, unlike in the case of a conventional rotating basket. , never bent at a sharp angle. Therefore, damage to the cloth 2 is greatly reduced. According to the results of the experiment, it was found that the useful life of the cloth was extended to about 2000 hours with the rotating basket of this invention, compared to about 1000 hours in the case of the conventional rotating basket. Furthermore, since the diameter of the inner end of the through hole 1a is larger than that of the other parts, the ratio of the total area of the through hole 1a to the area of the circumferential surface of the rotating basket 1,
In other words, the aperture ratio is increased, and the overefficiency is improved. According to experiments, when the conventional rotating basket and the rotating basket of this invention were compared under the same conditions, the concentration of the concentrated liquid increased from about 3% to about 4%.

As described above, according to the sludge centrifugal concentrator of this invention, the work of attaching the cloth 2 to the rotating basket 1 consists of fixing the holding plate 5 in a predetermined position with the fixing bolts 6, and fixing the holding plate 5 in a predetermined position with the fixing bolts 6. This can easily be done by performing the operations of attaching and attaching in any order. When the cloth 2 is installed in a predetermined position, the cloth 2 is appropriately tensioned between its center and peripheral edges, so it has the advantage that it does not wrinkle at all, not only during installation but also during overwork. .

Furthermore, if the inner end of each through hole of the rotating basket is made into a curved surface in which the diameter increases sequentially toward the tip, that is, toward the inner surface of the basket, damage to the fabric can be greatly reduced. The number of times of replacement is reduced, and together with a substantial improvement in overefficiency, the efficiency of centrifugal concentration is significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a passing device according to an embodiment of the invention, FIG. 2 is a sectional view taken along line A-A in FIG. 1, and FIG. 3 is a side view of a mounting pin used in the passing device. FIG. 4 is a sectional view showing the mounting state of the mounting pin. FIG. 5 is a cross-sectional view of the rotating basket of the same device taken along a plane passing through the center of its through hole, and FIG. 6 is an explanatory diagram showing the state of the cloth during centrifugation. 1... Rotating basket, 1a... Through hole, 2...
Cloth, 3... Mounting part, 4... Rotating shaft, 5... Holding plate, 6... Fixing bolt, 7... Positioning pin, 8
...Positioning hole, 9...Mounting pin, 9a...Head, 9b...Legs, 10...Mounting hole.

Claims (1)

[Scope of utility model registration request] A rotating basket having a truncated conical inner surface with an open large diameter end, and a large number of through holes bored in the peripheral wall of the rotating basket, each of which has a curved surface whose inner end gradually increases in diameter as it approaches its tip. and,
a frustoconical cloth disposed along the inner surface of the rotating basket; and a plurality of truncated conical cloths fixed to the rotating basket at their periphery by being inserted through the cloth and into the mounting holes of the rotating basket. A sludge centrifugal concentrator comprising a mounting pin, a disc-shaped presser plate placed inside the center of the cloth to press and fix the cloth, and a fixing bolt to fix the presser plate to the center of the rotating basket. .