JP2966270B2 - Horizontal centrifugal concentrator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal centrifugal concentrator in which sludge is rotated at high speed to forcibly perform solid-liquid separation by centrifugal force.

[0002]

2. Description of the Related Art Conventionally, as a horizontal centrifugal concentrator of this type, sludge is continuously supplied into a rotating bowl equipped with a screw conveyor, and solid-liquid separation is performed by centrifugal force while moving through the bowl. And concentrated liquid (condensed sludge) separately (for example, JP-B-63-31)
261 and JP-A-62-106856)
It has been known. In this device, solid-liquid separation is performed in the gap between the outer rotating outer cylinder and the inner cylinder having the inner screw conveyor, and the separated separated liquid and the concentrated sludge are separated from the outer cylinder by the end portion between the inner cylinder. Thus, the separated liquid is taken out along the inner cylinder, and the concentrated sludge is taken out from the inner peripheral part of the outer cylinder.

[0003]

In the above-mentioned conventional apparatus, the light separated liquid is transferred along the outer periphery of the inner cylinder, and the separated liquid contains a scum lighter than water. The scum floats on the surface (becomes innermost) and comes into contact with the inner cylinder, but since the part in contact with this inner cylinder has a slow flow, the scum is attached to the outer circumference of the inner cylinder. This will grow. In particular, in the treatment of sludge having a large amount of scum, the passage of the sludge between the outer cylinder and the inner cylinder becomes narrower due to the growth of the scum, and the concentration efficiency decreases, such as deterioration of separated water.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the conventional apparatus, in which annular weirs are provided at both ends of an inner cylinder, or the inner cylinder is formed in a drum shape. By doing so, an air layer can be formed on the outer periphery of the inner cylinder,
An object of the present invention is to provide a horizontal centrifugal concentrator that can prevent scum from adhering to an inner cylinder.

[0005]

The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. The horizontal centrifugal concentrator according to claim 1 is rotated at high speed. In the outer cylinder 1, an inner cylinder 4 provided with a screw blade 5 rotated with a relative speed difference from the outer cylinder 1 is housed, sludge is supplied from one end side of the screw blade 5, and solid-liquid separation is performed. In a device configured to discharge the separated liquid and the concentrated sludge from the end side, an annular weir plate 6 for forming an air layer 14 along the peripheral surface of the inner cylinder 4 is provided at both ends of the inner cylinder 4.
6 and a screw blade 5 is wound around the weirs 6 and 6 of the inner cylinder 4.

In the horizontal centrifugal concentrator according to the second aspect, an inner cylinder 4 provided with a screw blade 5 which is rotated at a relative speed difference from the outer cylinder 1 is accommodated in an outer cylinder 1 rotated at a high speed. In the apparatus, sludge is supplied from one end of the screw blade 5 and solid-liquid separated, and the separated liquid and the concentrated sludge are discharged from the other end.
Is formed in the shape of a drum with a large diameter and a small diameter of the intermediate portion 4b, and a screw blade 5 is wound around the inner cylinder 4.

[0007]

The present invention is constructed as described above, and the sludge flowing into the annular space 8 from the supply passage 9 is transported through the annular space 8 while being separated into solid and liquid by the rotation of the outer cylinder 1 and the screw conveyor 3. Then, the separated liquid will travel inside the separated concentrated sludge. After the liquid supply to the centrifugal concentrator is started, the supply liquid level rises from the outer periphery to the inner periphery in the annular space 8, so that the air contained in the sludge is close to the peripheral surface of the inner cylinder 4. However, the air is blocked by the weirs 8, 8 and forms an air layer 14 surrounding the inner cylinder 4 between the weirs 8, 8. Also,
In the device of the second aspect, the air layer 14 is formed so as to surround the inner cylinder 4 between both ends of the inner cylinder 4 having a large diameter. Therefore, the separated liquid containing the scum and close to the inner cylinder 4 is transferred without contacting the inner cylinder 4, and the scum is prevented from adhering to the inner cylinder.

[0008]

Embodiments of the present invention will be described below. In the figure, reference numeral 1 denotes a cylindrical outer cylinder, which has hollow shafts 2a and 2b projecting from the center of both end plates, supported by bearings (not shown), and rotated at high speed by a driving device. I have. In the outer cylinder 1, a screw conveyor 3 in which a screw blade 5 is wound around the inner cylinder 4 is accommodated. The inner cylinder 4 is formed in a cylindrical shape, and annular weirs 6 and 6 are provided on the outer periphery of both ends thereof. The screw blade 5 is wound around the outer periphery of the inner cylinder 4 extending between the weirs 6 and 6. Is equipped.

A hollow shaft 7 is provided at the center of both ends of the inner cylinder 4.
a, 7b are protruded, and the hollow shafts 7a, 7b
Are extended outwardly through the hollow shafts 2a and 2b, and are rotated with a slight relative speed difference from the outer cylinder 1 by the driving device. The proximal end of one of the hollow shafts 7a is communicated with a radial supply path 9 which opens at one end of an annular space 8 formed between the outer cylinder 1 and the inner cylinder 4, and the distal end is shown in the drawing. Is connected to the sludge supply pipe.

The base end of the other hollow shaft 7b is
Is connected to a radial discharge path 10 opened at the other end of the outer cylinder 1, and the tip end protrudes outward from the hollow shaft 2 b of the outer cylinder 1.
In the hollow shaft 7b, there is a flow gap 11 between the hollow shaft 7b and the inner circumference.
A sludge discharge pipe 12 is inserted therethrough, and a discharge pipe 13 that penetrates through the hollow shaft 7b in the diameter direction and opens to the outer peripheral portion of the annular space 8 is connected to the base end thereof.

In the apparatus having the above construction, the sludge flowing from the hollow shaft 7a flows into the annular space 8 from the supply passage 9 and is separated into solid and liquid by the centrifugal force of the rotation of the outer cylinder 1 and the screw conveyor 3 to form the annular space 8. It is transported inside. in the meantime,
The concentrated sludge containing a large amount of solids is separated and leans toward the inner surface of the outer cylinder 1, and the light separated liquid travels inside the concentrated sludge along the inner cylinder 4. Then, the concentrated sludge flows into an extraction pipe 13 opened near the inner surface of the outer cylinder 1 and is discharged out of the machine through a sludge discharge pipe 12, while the separated liquid is discharged through a discharge passage 10 opened near the peripheral surface of the inner cylinder 4. The fluid then flows into the hollow shaft 7b and is discharged out of the machine through the flow gap 11.

By the way, the separated liquid contains scum which is lighter than water, and these light components are sent close to the peripheral surface of the inner cylinder 4 in the process of separation and transfer.
At that time, the air is held between the weirs 6 and 6 provided at both ends of the inner cylinder 4, and the air layer 14 is formed at the boundary a with the water surface. Since the thickness of the air layer 14, that is, the height of the boundary a changes depending on the pressure in the outer cylinder 1 and the like, the boundary a is actually formed as shown by a dashed line in FIG. The operation is performed at a position slightly lower than the outer circumferences of 6, 6. The scum of the separated liquid existing near the boundary a is moved along the boundary a, and the scum is discharged without adhering to the inner cylinder. In this case, in order to ensure the formation of an air layer, air can be forcibly supplied from the outside to the inside of the device when the device is started or during operation.

FIG. 2 shows another embodiment of the inner cylinder 4 of the screw conveyor 3. The inner cylinder 4 in this embodiment has a drum-shaped cylindrical shape as a whole, and both end portions 4a, 4a are formed in a trapezoidal shape which is tapered inward from both ends and contracted. Intermediate part 4b between
Are smaller in diameter than both ends 4a. A screw blade 5 is wound around the outer periphery of the inner cylinder 4. In the embodiment of FIG. 2, the configuration other than the inner cylinder 4 is the same as that of the embodiment of FIG.

In the embodiment shown in FIG. 2, both ends 4a,
1a is formed larger in diameter than the intermediate portion 4b.
The same operation as that of the embodiment in which the weir plates 6 and 6 are provided can be obtained. That is, the air is supplied to both ends 4 of the inner cylinder 4 having a large diameter.
The air layer 14 is formed in a boundary a with the water surface, being held in the concave peripheral region between the a and 4a. Again,
In the actual operation, the boundary a is maintained at a position slightly lower than the outer circumferences of the both ends of the inner cylinder 4 having a large diameter, as shown by the chain line in FIG.

[0015]

As described above, the apparatus according to claim 1 is provided with dams at both ends of the inner cylinder in the screw conveyor, and the apparatus according to claim 2 is also configured such that both ends of the inner cylinder have the same diameter. Since the middle part is shaped like a drum with a small diameter, an air layer can be formed on the peripheral surface between both ends of the inner cylinder during the operation of the concentrator, whereby the separated liquid containing a large amount of scum is formed inside. The scum does not adhere to the inner cylinder without being in contact with the inner cylinder.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer cylinder 3 Screw conveyor 4 Inner cylinder 4a End part 4b Intermediate part 5 Screw blade 6 Weir board 7a, 7b Hollow shaft 8 Annular space 9 Supply path 10 Drain path 12 Sludge discharge pipe

Continued on the front page (72) Inventor Minoru Fukunaga 3-3-2 Nihonbashi Muromachi, Chuo-ku, Tokyo Co., Ltd. Kubota Tokyo Head Office (72) Inventor Hiroyoshi Minakami 3-3-2 Nihonbashi Muromachi, Chuo-ku, Tokyo Co., Ltd. Kubota Tokyo Headquarters (56) References JP-A-2-71859 (JP, A) JP-A-2-86652 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B04B 1 / 20

Claims (2)

(57) [Claims] An inner cylinder provided with a screw blade, which is rotated at a relative speed difference from the outer cylinder, is accommodated in an outer cylinder rotated at a high speed, and sludge is supplied from one end of the screw blade to form a solid-liquid. In an apparatus which separates and discharges a separated liquid and a concentrated sludge from the other end side, an annular weir plate for forming an air layer is formed at both ends of the inner cylinder along the peripheral surface of the inner cylinder. A horizontal centrifugal concentrator, wherein screw blades are wound between the weirs of the inner cylinder. 2. An inner cylinder provided with a screw blade, which is rotated with a relative speed difference from the outer cylinder, is accommodated in an outer cylinder rotated at a high speed, and sludge is supplied from one end side of the screw blade to form a solid-liquid. In a device that separates and discharges the separated liquid and the concentrated sludge from the other end side, the inner cylinder is formed into a drum shape with both ends large in diameter and the middle part small in diameter. A horizontal centrifugal concentrator characterized by winding screw blades.