JPH0448880Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to an improvement of an electrolytic treatment device used to improve the dewatering properties of sewage sludge, etc.

"Prior Art" Conventionally, it is well known that sewage sludge and the like can be electrolytically treated to improve its dewatering properties. for example,
Japanese Patent Publication No. 16351 of 1983 is for dissolving and removing impurities generated between electrodes in an electrolytic treatment of wastewater while flowing it.
No. 55163 is intended to prevent the formation of contaminants on the electrode surface during electrolytic treatment of wastewater.

``Problem that the invention aims to solve'' Conventionally, when electrolytically treating sewage sludge, etc., the narrower the distance between the positive and negative electrode plates, the better the electrolysis efficiency, but if this is too narrow, contaminants accumulate and the current cannot be applied. prevention, and the electrolytic efficiency decreases. If the electrode spacing is widened, the accumulation of impurities can be prevented, but the current density will be low and electrolysis will take time. The prior art disclosed in the above-mentioned publication is also aimed at solving the above-mentioned problems, but
The method of No. 16351 requires a chemical solution and a special device for supplying it, and the method of Utility Model Publication No. 52-55163, if used for electrolysis, can only be applied on a small scale.

``Means for solving the problems'' This invention solves the conventional problems as mentioned above, and also uses a special pump to circulate the stock solution to improve the hydrophobicity obtained by electrolysis. The sludge can be reformed into sludge with good dewatering properties without damaging the sludge floc, and it also eliminates bubbles that occur during electrolysis.

This invention will be explained in detail below.The gist is that a large number of electrode plates are arranged in parallel in an electrolytic cell,
A screw pump is installed upright on the tank wall on the side of the row of parallel electrode plates, the suction port of the screw pump is opened at the bottom of the electrolytic cell, and the discharge port is provided above the electrolytic cell. This is an opening in the distribution gutter.

In other words, part of the undiluted solution in the electrolytic cell is sucked in from the bottom by the screw pump and sprayed into the tank from the spray gutter, which circulates the undiluted solution in the tank and prevents foreign matter from accumulating between the electrode plates. There's nothing to do,
Efficient electrolysis is possible, but at this time,
Since this idea uses a screw pump to pump up a portion of the raw solution, it does not destroy the electrolytic flocs like conventional centrifugal pumps do.
It does not impair dehydration properties after the fact. In addition, this screw pump only needs to be installed along the tank wall, does not require piping equipment, etc. unlike conventional centrifugal pumps, and is structurally inexpensive.

Examples of this invention will be described below.

Embodiment In FIG. 1, reference numeral 1 denotes an electrolytic cell, and 2 denotes a large number of electrode plates arranged in parallel in the electrolytic cell, with positive and negative electrode plates arranged in parallel alternately. 3 is a screw pump installed along the side wall of the electrolytic cell, and its suction port 4 is the first
As shown in the figure, it is opened at the bottom of the electrolytic cell 1, and its discharge port 5 is opened at one end of a dispersion gutter 6 provided at the upper side of the electrolytic cell 1, as shown in FIG. be. As shown in FIGS. 3 and 4, this dispersion gutter 6 is designed to cause the stock solution to overflow from the weir plate 7 to eliminate bubbles generated on the surface of the electrolytic cell. Reference numeral 8 is a diffusion plate for diffusing the stock solution at the time of overflow, and the one shown in the figure is
The plate is twisted so that the stock solution drips gradually. Further, in FIG. 2, reference numeral 9 denotes a stirring blade, which is constructed in a loosely pitched spiral shape and is installed so as to force the stock solution supplied into the tank into the gap between each electrode plate. .

In the electrolytic cell configured in this way, the supplied stock solution is forced between each electrode plate by the stirring blade, as shown by the arrow in Fig. 1, where it undergoes electrolytic action and becomes hydrophobic. It is modified into a floc. In other words, the stirring blades 9 cause the raw solution in the tank to flow and be uniformly reformed without stagnation between the electrode plates. Above the spray gutter 6 for spraying the undiluted solution.
During electrolysis, a part of the stock solution is dispersed, so the electrode plates hold the gas and the flocs that float up are struck and defoamed, and at the same time they are pushed between the electrode plates, resulting in uniform reformation. It is something that can be done. In other words, in this type of conventional electrolyzer,
Fine flocs adhere to the electrode plate and prevent the passage of current, and the fine flocs hold the gas generated on the electrode plate, preventing the passage of current.
The fine flocs containing gas floated to the surface, dividing the raw solution into two layers, making it impossible to uniformly reform the raw solution.However, in the device of this invention, the fine flocs that floated are separated into two layers of the raw solution. Since it is beaten with a portion, it is possible to prevent the stock solution from separating into two layers, and it is also possible to suppress the foaming of flocs that float to the top by holding gas. In addition, since the device according to this invention uses a screw pump to pump up a portion of the stock solution, the reformed flocs in the stock solution are not destroyed when pumping the stock solution. Furthermore, since a screw pump is used, there is no need for piping or the like as in conventional centrifugal pumps, and the device has the advantage of being inexpensive.

"Effect of the invention" As described above, the device according to this invention makes it possible to uniformly and efficiently reform the stock solution in the electrolytic tank by making improvements to the stock solution circulation device in the electrolytic tank. In addition, the device is compact and can be constructed at low cost, and the practical benefits are significant.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of the electrolytic treatment apparatus according to this invention, taken along a plane passing through the screw pump shaft. 2 is a sectional view taken along the line A-A in FIG. 1, FIG. 3 is a sectional view taken along the line BB in FIG. 1, and FIG. 4 is a sectional view taken along the line D in FIG. 3. It is a sectional view along the -D line. Explanation of symbols, 1... Electrolytic tank, 2... Electrode plate, 3...
...screw pump, 4...suction port, 5...discharge port, 6...spreading gutter.

Claims (1)

[Scope of utility model registration request] A large number of electrode plates 2 are arranged in parallel in an electrolytic cell 1, and a screw pump 3 is installed upright on the tank wall on the side of the row of electrode plates arranged in parallel.
A undiluted solution dispersion gutter 6 whose suction port 4 is opened at the bottom of the electrolytic cell 1 and whose discharge port 5 is provided above the electrolytic cell 1
An electrolytic treatment device for sludge, etc. that has an opening inside.