JPH0985292A - Sludge recovery method and sludge recovery device in circulating water system - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To effectively prevent scale generated in a circulating water system. A water treatment device (2) in which a counter magnetic pole and a pair of electrodes made of different materials are arranged facing a water passage, and a pipe (1) is provided.
In part 5, the cross section of the water channel is changed to reduce the flow velocity of the circulating water, and the scale component is discharged from the lower portion 6 of the pipe to recover sludge. [Effect] Sludge can be collected in a part of the pipeline, and the sludge can be reliably collected with a simple structure to prevent generation of scale.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering sludge in a circulating water system, which prevents the occurrence of scales that adhere to the inner wall of a conduit pipe and cause various troubles in the circulating water system such as a cooling circulating water channel or a boiler. And a sludge recovery device.

[0002]

2. Description of the Related Art In a circulating water system such as a circulating water channel for cooling or a boiler, scale is gradually generated due to long-term use,
This adheres to the inner wall surface of the water channel and causes various troubles. For example, it adheres to a heat transfer surface or a pipe in a heat exchanger incorporated in a circulating water system pipe or the like, and causes a decrease in heat exchange efficiency, blockage of the pipe, generation of rust, or the like. Therefore, a method has been developed to prevent the generation of scale by applying an electric field or a magnetic field to the circulating water.

Specifically, electrodes made of different materials are placed opposite to each other so as to sandwich the water passage, and an electric field is applied to the water passage between the electrodes (JP-A-63-39690, etc.).
The electrodes and the permanent magnets that are installed to face each other are used in combination, and the electric field generated by these electrodes and the magnetic field generated by the permanent magnet are applied (Japanese Patent Laid-Open No. 5-57286, etc.) to prevent generation of scale. The scale component contained in the circulating water that has been subjected to the action of the electric field or magnetic field as described above grows as a crystal instead of becoming a scale, and moves in a floating state together with the circulating water. Since these crystals deposit as sludge on the bottom of the tank in the circulating water system, a recovery tank is provided at the bottom of the tank, and the sludge is taken out from this recovery tank.

[0004]

However, depending on the circulating water system, it may be difficult to provide a recovery tank due to space or structural restrictions. In that case, the operation of the circulating water system is stopped and sludge is removed from the tank. I need to take it out. It is difficult to perform such work frequently because it significantly reduces the operating efficiency of the circulating water system, and it is necessary to perform it after a considerable period of time. However, if sludge is not collected and accumulated for a long period of time, the scale components that have been sludged will scale, and will be eluted again in the circulating water, so scale will not be generated in a circulating water system where a recovery tank cannot be provided. There is a problem that it cannot be effectively prevented. Further, even in a circulating water system in which a recovery tank can be installed, there is a problem that installation costs and installation costs are high when the recovery tank is installed.

The present invention has been made in view of the above circumstances, and sludge in a circulating water system capable of efficiently collecting sludge with a simple device and effectively preventing generation of scale at low cost. An object is to provide a recovery method and a sludge recovery device.

[0006]

In order to solve the above-mentioned problems, the method for recovering sludge in a circulating water system according to the first aspect of the present invention is such that it faces a water passage and sandwiches it.
At least one of a magnetic pole of a counter electrode or a pair of electrodes made of different materials is provided, and at least one of a magnetic field and an electric field is applied to the circulating water passing through this water passage to change the cross section of the water passage in a part of the circulating water system. The flow rate of the circulating water is reduced by this, the scale component that moves with the circulating water is retained as sludge below this pipe, and this sludge is discharged from the pipe and recovered.

In the sludge recovery device in the circulating water system of the second invention, at least one of the magnetic pole of the opposite pole or the pair of electrodes made of different materials is installed so as to face the water passage and sandwich the water passage, and the sludge is circulated. It is characterized in that a pipe expanding part is provided as a flow velocity reducing part in a water-based pipe line, and a sludge discharging part is provided below the flow velocity reducing part.

In the sludge recovery system for circulating water according to the third aspect of the invention, at least one of the magnetic pole of the opposite pole or the pair of electrodes made of different materials is installed so as to face the water passage and sandwich it, and the sludge is circulated. It is characterized in that a water flow resistance material is provided inside the water pipe to form a flow velocity reducing portion, and a sludge discharge portion is provided below the flow velocity reducing portion.

A sludge recovery device for a circulating water system according to a fourth aspect of the present invention is the sludge recovery device according to the second or third aspect, wherein the flow velocity reducing portion is located immediately before the circulating water inflow side of the water passage in which at least one of the counter pole and the pair of electrodes is installed. It is characterized by being provided in.

The counter magnetic pole provided facing the water passage can be provided by installing a permanent magnet or an electromagnet. The electrodes made of different materials have different electrochemical series, and are directly connected to each other or connected via a resistor. If desired, an external power source may be provided. The above-mentioned magnetic pole and electrode may be installed independently, but it is desirable to install them side by side in order to efficiently generate sludge. In addition, the magnetic pole and the electrode may be provided not only in a single pair but also in a plurality of pairs. When a plurality of pairs are provided, they can be disposed in parallel or in series with the water passage. Further, these magnetic poles or electrodes are usually provided in the conduit, but the installation location is not particularly limited in the present invention.

Further, as a method of changing the cross section of the water channel in order to reduce the flow velocity of the circulating water, as shown in the second aspect of the present invention, a pipe expanding portion is provided to rapidly or gently increase the cross sectional area of the water channel. There is a method of arranging a resistance material as shown in the invention. Further, the flow velocity can be reduced by bending the pipe. The sludge discharge portion provided below the flow velocity reducing portion efficiently discharges the sludge accumulated below the flow velocity reducing portion, and can be configured by, for example, a drain pipe and a cock provided therein, and the circulating water system. It is desirable that the sludge can be quickly discharged without stopping the operation of.

The flow velocity reducing portion can be installed immediately before or after the magnetic pole or electrode is installed, as well as at any place in the conduit, or at a plurality of locations. However, in order to efficiently collect the sludge, it is desirable to provide it at a stage where the crystallized scale component grows and is easily deposited as sludge, that is, immediately before the installation position of the magnetic pole or the electrode. Further, since the crystallized scale component wears the surfaces of the magnetic poles and electrodes, in this respect also, it is desirable to provide the flow velocity reducing portion immediately before the magnetic poles or electrodes are installed.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. A water treatment device 2 that divides the water passage into four water passages is arranged inside a pipe (pipe) 1 through which the circulating water for cooling flows, and the vertical wall of the water treatment device 2 is attached in the thickness direction. 3 is composed of magnetized plate-shaped permanent magnets 3, and each permanent magnet 3 is arranged such that the facing permanent magnets and the facing surfaces have different polarities. In this embodiment, as shown in FIG. ) Arranged so that the magnetic flux flows from left to right. Further, an electrode is embedded on the lateral wall of the water treatment device 2 so that the surface is exposed to the water flow path, and the downward electrode 4a arranged on the upper side is made of an aluminum electrode,
The upward electrode 4b arranged on the lower side is composed of a carbon electrode. Both electrodes are externally connected via a resistor (not shown). Although the aluminum electrode and the carbon electrode are used as the pair of electrodes in this embodiment, the present invention is not limited to this combination, and various combinations of electrodes can be used.
It is also possible to use a combination of a titanium electrode and a carbon electrode.

Immediately before the circulating water inflow side of the water treatment device 2, an expanded pipe portion 5 is provided as a flow velocity reducing portion, and the expanded pipe portion 5 has a groove portion 5b formed below a normal diameter portion 5a. It has a shape with an increased cross-sectional area. Also, the groove portion 5b
A drain pipe 6 is connected to the center of the lower part of the cock 7 and a cock 7 for keeping the drain pipe 6 normally closed to the drain pipe 6.
Is provided.

When the circulating water was flowed in the pipe with the water treatment device 2 installed, the aluminum electrode 4a and the carbon electrode 4 were
Due to the difference in electrochemical potential from b, a weak current flowed between both electrodes with the aluminum electrode 4a as the anode and the carbon electrode 4b as the cathode, and an electric field was generated. The amount of the weak current is substantially determined by the resistance value of a resistor (not shown). In addition, a magnetic field is generated between the permanent magnets 3 and 3, and an induced current is generated in the same direction as the inter-electrode electric field by the Hall effect due to the water flow 8, and the strength of the electric field applied between the electrodes is increased by the synergistic effect. . In this embodiment, the magnetic field is applied synergistically. However, the magnetic field can be applied destructively.

By the action of the above magnetic field and electric field, the scale component aggregates into a crystal nucleus, and while moving in the circulating water in a floating state, the scale component is replenished to grow as a crystal. On the other hand, the circulating water is moving in the circulating water system including the pipe 1, and the flow velocity decreases due to an increase in the cross-sectional area of the water channel in the pipe expanding section 5. The scale component that has sufficiently grown crystals precipitates in the expanded pipe portion 5 as the flow velocity decreases, stays at the bottom of the groove portion 5b, and gradually accumulates. Then, if the cock 7 of the drain pipe 6 is opened as desired, the accumulated scale flows out surely and quickly together with the circulating water. Then, by immediately closing the cock 7, the scale can be promptly recovered without stopping the operation of the circulating water system. When this water treatment device 2 was used for a long period of time, almost no generation or adhesion of scale was found in the pipe 1. Also,
It is no longer necessary to install a scale collection tank in the tank.

Next, another embodiment will be described with reference to the accompanying drawings. Since the water treatment device of this embodiment has the same structure as that of the above-mentioned embodiment, the description thereof will be omitted. The flow velocity reducing portion 10 of this embodiment is one in which perforated plates 11 ... 11 are installed as a resistance material so as to close the lower half of the pipe 1 against a water flow, and the perforated plate 11 has a large number of through holes 11a.
Is formed, and a bottom portion thereof has a gap 11b with the pipe 1 so that circulating water can pass therethrough.
Further, the drain 6 and the cock 7 similar to those in the above embodiment are provided on the downstream side of the flow velocity lowering portion. In addition, it is desirable that the perforated plate 12 located on the most downstream side is not provided with a lower gap so that the sludge does not flow out.

When circulating water is caused to flow through the water treatment system as in the case of the above embodiment, the scale component becomes a crystal nucleus in the water treatment apparatus and grows as crystals in the circulating water. The circulating water hits the perforated plate 11 at the flow velocity lowering portion 10, becomes a turbulent state, and the flow velocity decreases. The circulating water is above the perforated plate 11 and the perforated plate 1.
11a of 1 and passes through the lower gap 11b of the perforated plate 11 slightly. On the lower side of the flow velocity lowering part,
The flow velocity is reduced by the perforated plate 10, the scale component of crystal growth settles downward to become sludge, and a part of the scale component slowly moves through the lower gap 11b below the perforated plate 11. When the cock 7 of the drain pipe 6 is opened as desired, the accumulated sludge is drained together with the circulating water.
After that, the cock 7 is closed. The sludge was efficiently and surely collected and removed even in this flow velocity decreasing portion. In this embodiment, the pipe having the same inner diameter as that before and after the flow velocity reducing portion is used, but the perforated plate may be arranged using a pipe having a large cross-sectional area.

[0019]

As described above, according to the sludge recovery method in the circulating water system of the present invention, at least the magnetic pole of the counter electrode or the pair of electrodes made of different materials faces the water passage and sandwiches the water passage. One is provided, and at least one of a magnetic field and an electric field is applied to the circulating water passing through this water passage to change the water passage cross section in a part of the pipe of the circulating water system to reduce the circulating water flow velocity and move with the circulating water. The scale component is retained as sludge below this pipeline, and this sludge is discharged and collected from the pipeline, so sludge consisting of the scale component can be easily and reliably collected in a part of the pipe, and the circulating water It is possible to effectively prevent the generation of scale without being restricted by the space or structure of the device.

Further, according to the sludge recovery device in the circulating water system of the present invention, at least one of the magnetic pole of the opposite pole or the pair of electrodes made of different materials is installed so as to face and sandwich the water passage. As the flow velocity reducing part is installed in the circulating water system pipe, a resistance material is provided in the pipe expanding part or inside the pipe, and the sludge discharging part is provided in this flow velocity decreasing part, so the sludge can be collected with a device with a simple structure, saving space. It enables low-cost sludge recovery. Further, in the above sludge recovery device, if the flow velocity reducing portion is provided immediately before the circulating water inflow side of the water passage in which at least one of the counter pole and the pair of electrodes is installed, sludge composed of scale components can be efficiently recovered, and It is possible to prevent the magnetic poles and electrodes from being damaged by the scale component crystal.

[Brief description of drawings]

FIG. 1 is a schematic front view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a water treatment unit, which is a cross section taken along line II-II of FIG. 1.

FIG. 3 is a perspective view showing a flow velocity decreasing portion, which is a cross section taken along line III-III in FIG. 1.

FIG. 4 is a front sectional view of a water flow lowering portion in another embodiment.

FIG. 5 is a sectional perspective view of the same.

[Explanation of symbols]

 1 Pipe 2 Water Treatment Device 3 Permanent Magnet 4a Electrode 4b Electrode 5 Expanded Portion 5b Groove 6 Drain Pipe 7 Cock 10 Water Flow Reduction Portion 11 Perforated Plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toru Mashita Toru Mashita 1-3, Takanodai, Yotsukaido, Chiba Prefecture Japan Steel Works (72) Inventor Yoshiaki Oda 1-1 Nikko, Fuchu-shi, Tokyo Nippon Steel Corporation In-house (72) Inventor Shoichi Matsuda 1-1 Nikkocho, Fuchu-shi, Tokyo Inside Japan Steel Works, Ltd.

Claims (4)

[Claims] 1. A water passage facing and sandwiching the water passage,
At least one of a magnetic pole of a counter electrode or a pair of electrodes made of different materials is provided, and at least one of a magnetic field and an electric field is applied to the circulating water passing through this water passage to change the cross section of the water passage in a part of the circulating water system. The sludge recovery method in the circulating water system is characterized in that the flow velocity of the circulating water is reduced, the scale component that moves with the circulating water is retained as sludge below the pipe, and the sludge is discharged from the pipe and recovered. 2. A water passage facing and sandwiching the water passage,
At least one of the opposite magnetic pole or the pair of electrodes made of different materials is installed facing each other, and the pipe of the circulating water system is provided with a pipe expanding part as a flow velocity reducing part, and a sludge discharging part is provided below the flow velocity reducing part. Sludge recovery system for circulating water system 3. Facing the water passage and sandwiching the water passage,
At least one of the opposite magnetic pole or the pair of electrodes made of different materials is installed facing each other, and a water flow resistance material is provided inside the circulating water system pipe as a flow velocity reducing portion, and a sludge discharge portion is provided below this flow velocity reducing portion. A sludge recovery system for circulating water 4. A sludge recovery device in a circulating water system, wherein the flow velocity reducing portion is provided immediately before a circulating water inflow side of a water passage in which at least one of a counter pole and a pair of electrodes is installed.