JPH0334261Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a sludge supply device for a pressure dehydrator such as a filter press.

Normally, in a pressurized dehydrator, sludge is supplied by a pump from a sludge tank such as a flocculation mixing tank, and at the same time, overaction is performed. Therefore, regardless of whether the dehydrator has a squeezing mechanism or not, the higher the supply pressure, the better the excess rate. However, the supply pressure by the pump is usually 15Kg/
The maximum supply pressure is about ^cm2 , and it is not possible to obtain a supply pressure higher than that.

In addition, a method of supplying sludge using a pressurized tank has been devised, but the maximum supply pressure that can be obtained with this method is limited to around 10 kg/cm ² .

The purpose of this invention is to increase the sludge supply pressure in the pressure dehydrator to improve dewatering efficiency.

That is, in this invention, a pressurized tank is interposed in the piping from the sludge tank to the sludge supply pump of the pressure dewatering machine, and the sludge in the pressurized tank can be supplied to the pump. By configuring
The sludge pressure supplied to the pressure dehydrator is the sum of the pressure applied by the pressure tank and the effective pressure of the pump (the difference between suction pressure and discharge pressure, and the pressure applied by the pump). It is possible to obtain a high sludge supply pressure that could not be obtained by using the method alone, and it is possible to improve the dewatering efficiency.

Hereinafter, embodiments of this invention will be described based on the accompanying drawings.

As shown in FIG. 1, in the piping from a sludge tank (not shown) such as a coagulation mixing tank to the sludge supply pump 1,
A pressurized tank 2 is provided, a compressor 5 is connected to the tank 2 via a flow rate control valve 3 and an on-off valve 4, and the pressure inside the tank 2 is adjusted by adjusting the control valve 3 while the compressor 5 is driven. be adjustable. In addition, 9 in the figure is an on-off valve interposed in the piping from the sludge tank to the pressurized tank 2.

A pressure transmitter 7 which also serves as a pressure detector for detecting the sludge pressure in this pipe is interposed in the pipe from the pump 1 to the pressure dehydrator 6, and the detected value of the transmitter 7 is sent to the controller 8. The controller 8 adjusts the rotational speed of the pump 1 and the degree of opening and closing of the control valve 3 based on the detected value.

The embodiment is configured as described above, and its operation will be explained next.

First, as shown in FIG. 2, since high supply pressure is not required at the beginning of sludge supply, the on-off valve 9 is opened and the on-off valve 4 is closed, and the sludge is supplied to the pressurized dehydrator 6 only by the pump 1. . Therefore, instead of interposing the tank 2 in the piping from the sludge tank to the pump 1 as in the embodiment, the sludge tank and the pressurized tank 2 can be connected to the pump 1 via a switching valve through separate piping, Sludge may be selectively supplied to the pump 1 from a sludge tank or a pressurized tank using a switching valve.

Supply by only the pump 1 is continued, and the supply pressure is transmitted to the controller 8 by the transmitter 7.
When the detected value of the transmitter 7 or the supply time reaches the desired value, the on-off valve 9 is closed and the on-off valve 4 is opened.
Thereafter, the controller 8 adjusts the opening/closing degree of the control valve 3 and the rotation speed of the pump 1 based on the detected value of the transmitter 7, and adjusts the sludge pressure in the pressurized tank 2 and the discharge pressure of the pump 1. Sludge is continued to be supplied to the pressure dehydrator 6 at a desired pressure.

During this operation, the sludge supply pressure to the dehydrator 6 is the pressure in the pressurized tank 2 plus the effective pressure of the pump 1, which lowers the supply pressure compared to the conventional sludge supply using only a pump or only a pressurized tank. It is possible to obtain high dewatering efficiency. The sludge supply pressure at the time of switching from the sludge supply using only the pump 1 to the sludge supply including the pressurized tank 2, that is, the desired value of the supply pressure, may be set appropriately, for example, from 3 to 8 Kg/ ^cm2 .

In the embodiment, the sludge was initially supplied using only the pump 1, but it is not necessary to do so, and the pressurized sludge in the pressurized tank 2 can be supplied to the pressure dehydrator 6 using the pump 1 from the beginning of supply. In addition, as shown by the chain line in Figure 1, on-off valves may be provided before and after the pump 1, and a bypass pipe may be provided so that the pressurized sludge in the pressurized tank 2 is transferred to the pump 1 at the beginning of supply. The pressurized sludge is directly supplied to the pressure dehydrator 6 without passing through the pump 1, and after the supply pressure or supply time reaches the desired value, the pressurized sludge is passed through the pump 1.
Alternatively, the water may be supplied to the pressurized dehydrator 6.

Furthermore, it goes without saying that this invention can be applied to either a pressurized dehydrator without a squeezing mechanism or a pressurized dehydrator that has a squeezing mechanism.

[Brief explanation of the drawing]

FIG. 1 is a schematic piping diagram of an embodiment of the sludge supply device for a pressurized dewatering machine of this invention, and FIG. 2 is a diagram showing the relationship between elapsed time and sludge supply pressure for explaining the operation of FIG. 1. 1... Sludge supply pump, 2... Pressurized tank, 5
... Compressor, 6 ... Pressure dehydrator.

Claims (1)

[Scope of utility model registration request] Sludge of a pressurized dehydrator in which a pressurized tank 2 is interposed in the piping from the sludge tank to the sludge supply pump 1 of the pressurized dehydrator 6, and the sludge in the pressurized tank 2 can be supplied to the pump 1. Feeding device.