JPH0671300A - Concentrator - Google Patents

Abstract

PURPOSE:To shorten the time required for concentration and to miniaturize a concentrator by arranging plural electrodes at specified intervals in parallel with the bottom surface in a concentrating tank to connect them to a power source and selectively applying voltage to an arbitrary electrode through a current switching device. CONSTITUTION:In a concentrating tank 1, plural electrodes 2 are arranged from an electrode 21 in the first stage parallel to the bottom surface in order at equal intervals upwards in parallel with each other in a multistage. The electrodes 2 each are independently connected to a current switching device 3 outside the tank. Arbitrary two electrodes 2 are selected and connected to a DC power source 1 to apply DC voltage to them. For example, first the electrodes 26, 28 are selected and used as an anode and a cathode respectively and DC voltage is applied to them to accelerate the sedimentation of suspended particles by an electrophoresis phenomenon. When the setting interface is lowered, the electrodes 27, 25 are selected to accelerate the sedimentation of suspended particles similarly. The operation is repeated in such a manner, and causing the concentration to be promoted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concentrating device for removing water to reduce the volume of muddy water or muddy substances, and particularly to improve the concentration efficiency by applying a DC voltage to the liquid to be concentrated by an electrophoretic phenomenon. It was

[0002]

2. Description of the Related Art Conventionally, when concentrating muddy water or the like to reduce its volume, the liquid to be concentrated is filtered through a filter cloth laid on a grid on the bottom of the filter in the filter or the liquid to be concentrated in the tank. The supernatant was removed by waiting for the suspended particles therein to settle to obtain a concentrated solution.

[0003]

In the concentration by the conventional filtration method, the deterioration of the filtration function caused by the clogging of the filter cloth during the filtration cannot be avoided, and there is a serious problem in terms of efficient concentration. . In the gravity settling method, which waits for the spontaneous settling of suspended particles in the liquid to be concentrated in the concentrating tank, the suspended particles are negatively charged, so that solvation easily occurs, and the sedimentation speed becomes extremely slow. It took a long time. Therefore, the present invention has an object to increase the concentration efficiency by applying a DC voltage to the liquid to be concentrated to accelerate the sedimentation speed of the suspended particles by an electrophoretic phenomenon.

[0004]

In order to achieve the above object, the present invention provides a concentrator for removing water from muddy water or mud-like substances, in which a plurality of electrodes are arranged at predetermined intervals from the lower part to the upper part in the concentration tank. Is arranged in parallel with the bottom surface, and each electrode is connected to a power source through a current switching device, so that two electrodes can be arbitrarily selected from a plurality of electrodes and a voltage can be applied between the electrodes. did.

[0005]

The suspended particles in the liquid to be concentrated in the concentration tank are usually negatively charged, and the sedimentation speed thereof is extremely slow. Therefore, the electrode is immersed in the liquid to be concentrated, and the cathode is placed above the concentration tank.
When the anode is placed below and a direct current voltage is applied between both electrodes, the suspended particles that are negatively charged by the electrophoretic phenomenon are electrically attracted to the anode below the concentrator, and the suspended particles settle. Is promoted. As a result, the liquid to be concentrated separates into a supernatant layer of the upper layer and a concentrated layer of the suspended particles of the lower layer at the boundary of the sedimentation interface. On the other hand, in the concentrating tank, a plurality of electrodes are arranged in parallel in multiple stages while maintaining a predetermined interval, and even if the capacity of the liquid to be concentrated decreases due to the progress of concentration, some electrodes among the plurality of electrodes must be used. Is soaked in the liquid to be concentrated. Therefore, the two electrodes are selected so that the sedimentation interface is sandwiched from the electrodes immersed in the liquid to be concentrated each time, even if the volume of the liquid to be concentrated decreases as the concentration proceeds and the sedimentation interface also drops. In the current switching device, the electrode above the sedimentation interface is connected to the cathode side of the power supply, and the electrode below the sedimentation interface is connected to the anode side of the power supply, and a DC voltage is constantly applied between the two electrodes to suspend suspended particles. Sedimentation can be promoted.

[0006]

EXAMPLE This example will be described with reference to FIG. In the concentrating device according to the present invention, the plurality of electrodes 2 (21 to 28) arranged in multiple stages in the concentrating tank 1 promote the sedimentation of suspended particles in the liquid to be concentrated in the concentrating tank 1 and the supernatant thereof. Drain the liquid,
The liquid to be concentrated can be reduced in volume and concentrated. In the concentrating tank 1, a plurality of electrodes are arranged in parallel from the first-stage electrode 21 which is arranged slightly above the bottom of the concentrating tank 1 in parallel with the bottom surface and which are arranged at equal intervals in the upward direction. It is arranged. The attachment position of the uppermost electrode 28 is set to a position slightly lower than the height of the water level when the concentration tank 1 is filled with the liquid to be concentrated. In this embodiment, eight electrodes are arranged in parallel in multiple stages, but of course the number of electrodes may be changed depending on the capacity of the concentrating tank. Further, each of the plurality of electrodes 21 to 28 has substantially the same size as the bottom surface of the concentrating tank 1, and further, a large number of permeation eyes are provided on the electrode surface so that liquid can smoothly permeate, Are made on a corrugated metal grid.

Each of the electrodes 2 is independently connected to a current switching device 3 provided outside the tank, and the plurality of electrodes 21 to 28 arranged in multiple stages in the concentration tank 1 are appropriately connected by the current switching device 3. Select any two electrodes from
Of the two electrodes, the lower electrode is used as an anode and the upper electrode is used as a cathode, which is connected to a DC power source 4 outside the tank, so that a DC voltage can be applied between the two electrodes. There is. By applying the above DC voltage between the two electrodes, the negatively charged suspended particles between the two electrodes were settled to the anode side below the concentrating tank by the electrophoretic phenomenon, and the suspended particles were reduced. The supernatant liquid of the upper layer of the liquid to be concentrated can be appropriately discharged through a discharge pipe 5 having an opening / closing valve 5a on the upper side wall of the concentration tank. Furthermore, on the lower side wall of the concentration tank,
A discharge pipe 6 having an on-off valve 6a is provided so that the concentrated liquid after discharging the supernatant liquid can be discharged.

That is, as the supernatant liquid is appropriately discharged and the concentration proceeds, the liquid surface of the liquid to be concentrated gradually lowers accordingly, but the liquid to be concentrated is discharged from the electrode immersed in the liquid to be concentrated each time. Select two electrodes so as to sandwich the sedimentation interface, which is the interface between the supernatant layer and the concentrated layer, and apply a DC voltage by the current switching device with the electrode above the sedimentation interface as the cathode and the electrode below as the anode. Meanwhile, it is possible to accelerate the sedimentation of suspended particles. For example, first, the electrodes 26 and 28 are selected, and a direct current voltage is applied with the electrode 26 as an anode and the electrode 28 as a cathode to promote the sedimentation of suspended particles, and when the sedimentation interface is lowered, the electrodes 27 and 25 are formed. Then, DC voltage is further applied by using the electrode 25 as an anode and the electrode 27 as a cathode to promote the sedimentation of suspended particles. By repeating this operation, the DC voltage is applied to promote concentration. is there.

Further, a sensor for automatically sensing the sedimentation interface of the concentrated liquid is provided in the concentration tank 1, and the current switching device 3 is controlled by the detection signal of the sensor to automatically detect the sedimentation interface in the concentrated liquid. Two electrodes to be sandwiched may be selected so that a DC voltage can be applied. Further, the electrode does not have to be an integrated planar electrode having substantially the same size as the bottom surface of the concentrating tank 1, and a plurality of electrodes may be shared to cover the entire voltage application surface. In the present embodiment, the lower electrode was used as the anode and the upper electrode was used as the cathode. However, when the suspended particles are positively charged, the lower electrode is of course the cathode and the upper electrode is of course. May be used as an anode and a DC voltage may be applied.

[0010]

According to the present invention, a DC voltage can be continuously applied between two electrodes in a liquid to be concentrated whose volume is reduced in accordance with the progress of the concentration process, which promotes sedimentation of suspended particles. ,
The concentration efficiency can be greatly improved. As a result, the processing capacity of the concentrating tank is improved, and it is possible to shorten the concentrating time and the downsizing of the concentrating device, which conventionally required a long time.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view of the front of a concentrating device.

[Explanation of symbols]

 1 Concentrator 2 Electrode 3 Current switching device 4 DC power supply

Claims (1)

[Claims] 1. A concentrator for removing water from muddy water or mud-like substances, wherein a plurality of electrodes are arranged parallel to the bottom surface at a predetermined interval from the lower part to the upper part in the concentrating tank, and further each electrode is switched to a current. A concentrating device characterized in that it is connected to a power source through the device, two electrodes are arbitrarily selected from a plurality of electrodes, and a voltage can be applied between the electrodes.