JPS6137990B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a vertical centrifugal concentrator.

In sewage treatment, there is a step of thickening sludge during the treatment of sludge discharged from a settling tank, and it has been proposed to use centrifugal force to thicken the sludge. The vertical centrifugal thickener that has been proposed in the past for use in such sludge concentration supplies sludge into a rotating lid with an opening at the top, and overflows separated water from a fixed gap at the top of the rotating lid. The thickened sludge accumulated on the body circumferential wall is drawn out by stopping the sludge supply when the accumulated amount becomes constant and inserting one end of the sludge drawing pipe into the thickened sludge layer. However, in this type of system, since the diameter of the sludge drawing pipe is small, it takes a long time to remove the sludge, resulting in poor efficiency.

In view of the above-mentioned points, the present invention provides a vertical centrifugal thickener that can remove sludge in a short time.One embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a bottomed rotary cylinder having an opening at one end, and the rotary cylinder 1 is arranged with the opening at one end facing upward and the axis thereof being vertical. The rotating cylinder 1 is rotated around a vertical axis by an electric motor 2 via a transmission mechanism 3 and a hollow shaft 4 which also serves as a slurry supply pipe. The circumferential wall of the rotating cylinder 1 is formed into an inverted truncated conical shape whose diameter gradually increases toward one end, and an annular flange 5 projecting radially outward is integrally formed at one end edge of the circumferential wall. It is installed protrudingly. Reference numeral 6 designates an annular weir plate whose outer circumferential portion faces the annular flange 5, and an annular seal member 7 is fixed to the outer circumferential portion of the lower surface of the weir plate 6. is in close contact with the top surface of the This weir plate 6 is fixed to the lower edge of a rotary lid 8 that covers one end of the rotary cylinder 1, and the rotary lid 8 is attached to the empty shaft 4 via a bearing 9. It is slidable in the axial direction with respect to the hollow shaft 4 and rotates together with it.
An annular flange portion 8a formed at the upper end of the rotary lid body 8 is connected to a pair of support plates 1 that protrude from the tips of the piston rods 10a of the plurality of hydraulic cylinders 10.
1a and 11b through bearings 12, and the rotary lid body 8 is supported by a hydraulic cylinder 10.
It can be raised and lowered by 13 is the rotary lid body 8
and a fixed case that covers one end of the outer circumferential wall of the rotary cylinder body 1. An annular partition plate 14 is provided protruding from the inner surface of the bottom wall of the case 13, and the partition plate 14 separates the separation water trough 15 and The thickened sludge torfu 16 is divided. Separated water discharge holes 17 are formed in the peripheral wall of the rotary lid body 8 at appropriate intervals in the circumferential direction, and annular holes are formed in the peripheral wall of the rotary lid body 8 to guide the separated liquid discharged from the separated water discharge holes 17 to the separated water turf 15. A guide plate 18 is fixed.

A sludge transport pipe 19 is connected to the upper end of the hollow shaft 4 via a swivel joint (not shown), and a sludge outlet 20 is formed at the bottom of the rotating cylinder 1. ing. 21 and 22 are bearings that rotatably support the hollow shaft 4;
The lower bearing 22 also rotatably supports the rotating cylinder 1. Note that the bearing 9 is attached to the case 13.
installed on.

Next, the operation will be explained. The sludge supplied into the rotary cylinder 1 from the sludge outlet 20 via the sludge transport pipe 19 and the hollow shaft 4 is subjected to centrifugal force due to the rotation of the rotary cylinder 1, and its solid components are transferred to the peripheral wall of the rotary cylinder 1. The thickened sludge layer A is separated into a thickened sludge layer A on the inner surface of the peripheral wall and a separated water layer B inside the thickened sludge layer A. As the sludge is supplied, the water surface of the separated water layer B approaches the axis of the rotating cylinder 1, and the separated water flows over the weir plate 6 and reaches the outer periphery inside the rotating lid 8, and the separated water discharge hole It is discharged from 17. This separated water is guided to the separated water trough 15 by the guide plate 18, and is discharged to a predetermined location via a discharge pipe (not shown) connected to the separated water trough 15. On the other hand, as sludge is supplied, the thickened sludge layer A
surface approaches the axis of the cylinder 1. When the surface of the thickened sludge layer A reaches the inner peripheral edge of the weir plate 6, the supply of sludge is stopped, and the hydraulic cylinder 10 is operated to raise the rotary lid body 8. As a result, the weir plate 6 fixed to the lower edge of the rotary lid body 8 and the weir plate 6
The sealing member 7 fixed to the outer periphery of the lower surface of the rotating cylinder 1 rises, and the sealing member 7 and the annular flange 5 of the rotary cylinder 1
A gap is created between the thickened sludge trough 16 and the thickened sludge.
It is discharged to a predetermined location via a discharge pipe (not shown) connected to. When the thickened sludge is discharged from the gap into the thickened sludge trough 16, the hydraulic cylinder 10
is operated to lower the rotary lid body 8, firmly pressing the sealing member 7 against the upper surface of the annular flange 5, and supplying sludge into the interior of the rotary cylinder body 1 again. By repeating the above operations, sludge concentration is performed one after another.

In this way, when a predetermined amount of thickened sludge has accumulated in the rotating cylinder 1, the weir plate 6 is raised to create a gap between the seal member 7 and the annular flange 5, and centrifugal force is applied from this gap. Since the concentrated sludge is then discharged, the concentrated sludge can be discharged in an extremely short period of time, and operational efficiency can be greatly improved.

In the above embodiment, an example was described in which the hydraulic cylinder 10 was used as a lifting device for the rotary lid 8, but it goes without saying that various types such as an air cylinder or an electric motor can be used instead of the hydraulic cylinder 10.

As described above, according to the present invention, the sludge outlet is formed in the hollow shaft whose both ends are rotatably supported by bearings, and the function of the rotating shaft of the rotating cylinder and the function of the sludge supply pipe are combined into the hollow shaft. Since it can be used for both purposes, there is no need to install a separate slurry supply pipe, which simplifies the configuration and reduces costs. Since there is no eccentricity, vibration can be reduced and the support structure can be simplified. In addition, the weir plate is provided so that it can be raised and lowered together with the rotary lid, and the separated water discharge hole is located radially outward from the inner periphery of the weir plate, so that the separated water that has exceeded the weir is immediately drained out of the rotary lid. Water flows to the circumferential side and is reliably drained through the separated water discharge holes located radially outward from the inner circumferential edge of the weir plate, allowing for good water drainage.
By raising the weir plate, the thickened sludge is discharged from the gap between the weir plate and the upper edge of the rotating cylinder due to centrifugal force, which allows the discharge of the thickened sludge in an extremely short time, greatly improving operational efficiency. .

[Brief explanation of the drawing]

The drawing is a schematic sectional view showing one embodiment of the present invention. 1...Rotating cylinder body, 4...Hollow shaft (sludge supply pipe), 6
...Weir plate, 7... Seal member.

Claims (1)

[Claims] 1. A hollow shaft whose both ends are rotatably supported by bearings, a rotary drive device that rotates this hollow shaft around its axis, and whose upper end is open and whose bottom wall center part is externally fitted and fixed to the hollow shaft. a rotary cylinder having an inverted truncated conical shape; a rotary lid body that is attached to the hollow shaft so as to be movable in the axial direction and covers an upper end opening of the rotary cylinder;
an elevating drive device that reciprocates the rotary lid along the axial direction of the hollow shaft; and an elevating drive device that extends radially inward from the lower end of the rotary lid to cover the outer periphery of the upper opening of the rotary cylinder. an annular weir plate, an annular sealing member disposed between the weir plate and the upper edge of the rotary lid body, a separated water discharge hole bored in the outer peripheral wall of the rotary lid body, and a separated water discharge hole formed in the hollow A vertical centrifugal concentrator configured to include a sludge outlet formed in a portion of a shaft located inside the rotary cylinder body, and to supply sludge into the rotary lid body through the hollow shaft.