JPS5847207B2 - Equipment for removing sludge in settling tanks - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention is suitable for removing sludge from the bottom of a settling tank by means of at least one siphon pipe with a controllable discharge rate, which is attached to a moving bridge and opens into a sludge channel. related to the equipment.

Such a device is known from US Pat. No. 3,669,271, in which the sludge suction and discharge device is provided with a plurality of sludge suction pipes opening into a common sludge drainage channel.

Since the sludge ditch is provided with one vertically adjustable tubular overflow weir, it is only possible to control all suction pipes in common at any given time.

Furthermore, the adjustment of the overflow weir cannot be changed along with the movement of the bridge.

During operation of the settling tank, sludge of the same concentration as possible must be removed from the settling tank by means of a discharge device.

In circular settling tanks, for example, the sludge concentration differs in the individual annular clarification zones, and in long settling tanks, differences occur along the flow direction.

In addition, the height and density of the sludge layer of settled sludge are not equal in all parts of the settling tank.

Since the amount of settled sludge also varies during the day according to the different sediments of the sewage and the load of the sewage, it is desirable to take this factor into account during desludging.

Already, the discharge of the siphon tube can be determined individually, e.g. electrically.
Control by hydraulically or pneumatically driven valves is envisaged.

However, such control must be carried out in proportion to the amount of incoming raw water and the resulting amount of settled sludge, making the control system very complex and expensive.

Another idea is to pump the sludge not by hydrostatic overpressure (by means of individual pumps into a fixed sludge ditch, but by varying the pump output and rotational speed).
For example, it can be adjusted by a static frequency converter.

Again, adjusting the settling sludge in each part of the settling tank would be complex and expensive.

Another disadvantage of using pumps to evacuate sludge is the required maintenance expense.

In another known device, as described in German Patent Publication No. 1813634, rotary flaps are attached to the outlet orifice of the siphon pipe located below the sludge level in the sludge discharge channel. Controlled via roller lever.

In this case, the entire control device is located mostly in the sludge area and is therefore subject to considerable interference in its operation by the solid and fibrous substances contained in the sludge, so that the control range of the lateral rotary flaps is limited. It is very expensive to modify and it is not possible to inspect and sample several siphon tubes.

The object of the present invention is to provide a method for removing sludge from a settling tank, such that control can be carried out in a simple and effective manner over the local and/or temporal changes in the settled sludge in the settling tank. The purpose is to provide equipment.

This purpose, according to the invention, is to provide a device for removing sludge from the bottom of a settling tank of the type mentioned at the outset, in which the discharge rate is controlled differently for different areas of the bottom of the settling tank, each of which is removed by a siphon pipe. This is achieved by featuring the following characteristics.

In particular, the control can be carried out by moving the bridge.

Then, while the bridge is stopped, sludge discharge is automatically stopped.

It is also possible to control the discharge rates of a plurality of siphon tubes removing different settling tank areas independently of each other.

The present invention provides a sludge removal chamber that is equipped with a plurality of siphon pipes that are attached to a bridge and open into a sludge drainage groove, and that these siphon pipes have valves and the like to control the amount of sludge discharged, and that are movable by the bridge. is in communication with each siphon tube.

The valves of the sludge chamber have a common control device in order to perform the sludge removal using the siphon pipe, and the joint valves each have a lever and a lever pivotably connected to a common shaft to which the control device is connected. Adjustment means are provided for varying the respective effective lengths of the connecting strip via the connecting rod as well as the lever and the connecting rod, or one of them.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

The sewage is delivered to a central structure 2 at the center of the circular settling tank 1 shown in FIGS. 1 and 2.

The sludge settles at the bottom of the sedimentation tank 3, and the clarified sewage flows into the tank 4.
is discharged through the

A bridge 5 is rotatably mounted on the central structure 2 and pivots on wheels 6 over the circular settling tank wall 7.

Attached to the bridge 5 are scrapers 8, these scrapers 8, during the rotation of the bridge,
The sludge settled at the bottom 3 of the settling tank is collected and sent to the orifice at the inlet end of the pipe 9.

The pipe 9 is designed as a siphon pipe and suctions the sludge and transfers it to the annular sludge channel 10 of the central structure 2.

At the outlet end 11 of the siphon pipe 9, in conjunction with the main pipe, a mud removal chamber 12 is provided, which is attached to the bridge 5 and can rotate together with the bridge.

When there are a plurality of siphon pipes, the mud removal chamber 12 can be configured by a common collection tank subdivided by partition walls 13.

As can be seen in FIG.
, whose cross section and overflow height can be varied by an overflow valve 15.

It is advantageous to arrange the top edge 16 of the hole higher than the bottom edge of the siphon tube 9, so that the outlet orifice 11 is always below the liquid level 17 in the discharge chamber 12, so that the siphon tube 9 Air intrusion will not cause discharge to be stopped.

Connecting overflow valve 15 to forks 18 and 19 and connecting rod 20
It is connected to the lever 21 by.

A lever 21 is attached to a rotation shaft 22.

As adjustment means for changing the effective length of the lever 21 and the effective length of the connecting rod 20, a set screw 25 and a threaded connection portion 23 are provided, respectively.

Since the length of the connecting rod 20 can be adjusted by means of the threaded connection 23, the height of the overflow edge 24 of the overflow valve 15 can be varied for one equal angular position of the lever 21.

The fork 19 is slidably attached to the lever 21 by a set screw 25.

According to this means, the stroke distance of the overflow valve 15 can be adjusted variously for the same rotation angle of the lever 21.

Each lever 21 associated with the sludge chamber 12 and the overflow valve 15 is mounted on a common shaft 22 which is mounted on a bracket 26 of the bridge 5.

This shaft 22 is connected to a pivot arm 27 which is actuated via a rod 29 by an adjusting drive 28, for example electrical, hydraulic or pneumatic.

The stroke movement of the adjusting drive 28 can be generated by a gear or pinion connected to the shaft 22, or the shaft 22 can be adjusted directly by a rotary motor drive.

In practice, first of all, the basic discharge rate corresponding to the average settled sludge in the area is adjusted by lengthening or shortening the connecting rod 20 for each siphon tube.

The control characteristics of each overflow valve 15 are then individually adjusted by lengthening or shortening the lever arm 21.

According to this means, it is possible to cope with changes in the settled sludge that act proportionally and non-linearly by proportionally changing the discharge rate.

The pivoting arm 27 can also be adjusted via a rod 29' extending on the edge of the settling tank, for example by means of an angle lever 30 and a sliding track 33 arranged on the edge of the settling tank.
The rod 29' is adjusted by means of rollers 31 guided by the rod 29' such that one or more control strokes are imparted to the rod 29' during each rotation of the bridge.

This type of control via the settling tank edge is particularly advantageous in the case of rectangular settling tanks.

This is because in this case the slip trajectory can be made to match the sludge distribution at the edge of the settling tank.

It is also possible to make the sliding trajectory vertically adjustable in order to adapt it to the settling of the sludge.

If the settling tank is long, the evacuation device is arranged to suck in sludge in both directions of movement of the bridge, so that the required ejection speed is different for the two directions of movement.

For this reason, in the end region of the settling tank, mud removal in one direction is immediately followed by mud removal in the opposite direction again.

To take this into account, mutually effective control devices with different control characteristics must be provided for the two movement force directions.

If controlled sliding devices are used, for this purpose:
Two sliding elements can be provided, on which sliding tracks the guide roller 31 moves through several locations.

If the discharge speed is to be increased, it is advantageous to arrange the overflow valves 15 on both sides of the sludge chamber 12, thereby reducing the overflow height by approximately half and making the stroke of the overflow valves 15 even shorter. It is possible to do this.

A rod 34 disposed above the overflow valve 15 connects a transverse member 35 for fixing the coupling fork 18 to the overflow valve 15; Indications are provided to help guide and easily adjust the desired discharge rate.

In addition to overflow valves, it is also possible to use diaphragm valves or throttle valves which control the flow cross section of the drainage orifice, which is always under water.

A combination of both control types can also be applied to the sludge chamber or to the same valve.

[Brief explanation of drawings]

Figure 1 is a side sectional view showing a circular settling tank with a device for removing sludge from the bottom of the settling tank, Figure 2 is a plan view of the settling tank shown in Figure 1, and Figure 3 is the same as shown in Figure 1. FIG. 3 is an enlarged partial view of the device. 3...Bottom of sedimentation tank, 5...Bridge,
9...Siphon pipe, 10...Sludge drainage ditch,
12...Sludge removal chamber, 15...Valve, 20.
...Connecting rod, 21...Lever 27...
...Rotating arm, 28...Adjustment drive device, 29.
·····rod.

Claims (1)

[Claims] 1. Equipped with a plurality of siphon pipes that are attached to a movable bridge and open sludge drainage grooves, and these siphon pipes are equipped with valves, etc. to control the discharge amount according to changes in the settled sludge in the settling tank. In a device for removing sludge from the bottom of a sedimentation tank using a siphon pipe, in which a movable sludge chamber is provided with a bridge and communicates with each siphon pipe, the valve 15 of each sludge chamber 12 is common. Each part 15 is connected to a common shaft 22 to which the control device is connected via a lever 21 and a connecting rod 20 that are pivotally connected to each other, and the lever 21 and the connecting rod 20 A device characterized in that adjustment means are provided for varying the effective length of each or one of them.