JPS61181591A - Water treating device for removing electrical scale and water treatment - Google Patents

Abstract

PURPOSE:To peel effectively the scales deposited on an electrode by providing at least one couple of both the positive and negative electrodes mutually parallel in the specified interval along the lengthwise direction of a tubular vessel main body and connecting a positive and negative current changeover device with both the electrodes. CONSTITUTION:At least one couple of both the positive and negative electrodes are provided mutually parallel in the specified interval along the lengthwise direction of a tubular vessel main body which is provided with an inflow port of water to be treated and an outflow port of the treated water and a positive and negative current changeover device is connected with both the positive and negative electrodes. As a result, the scales deposited on the electrode are efficiently peeled to keep beautifully both the electrode surfaces always and the current density between the respective electrodes is stabilized and the scale removing capacity such as the scale prevention and the scale deposition is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electric scale removal water treatment device and a water treatment method thereof. More specifically, this article relates to an electric scale removal water treatment device that causes extremely low scale damage and can be operated continuously for a long period of time, and a water treatment method using the same.

(Conventional technology) Water heaters, water supply and drainage pipes, heat exchangers, etc. in factories, buildings, homes, etc.
In boilers, cooling towers, etc., depending on the water quality, limescale (hereinafter referred to as scale) derived from rust and inorganic compounds such as calcium and magnesium may form.
This can clog the device or significantly reduce heat transfer efficiency.

Conventionally, methods such as using distilled water or ion-exchanged water or injecting chemicals have been used to prevent the formation of this scale, but the former is costly, and the latter poses a problem of contaminating the wastewater. . In order to solve such problems,
A so-called electric water treatment device has been proposed to prevent the generation of scale due to electrolysis (Japanese Unexamined Patent Publication No. 56-12
9.085, JP-A-58-17.888 and JP-A-59-73,096).

These electric type (magnetic type, high voltage type, low voltage type) water treatment equipment is capable of handling electrically charged substances such as calcium ions and magnesium ions contained in heat exchange water or cooling water. It is a device that prevents loss of charge or precipitation by giving a charge, and also prevents slime damage, corrosion damage, etc.

The mechanism is to place positive and negative electrodes in a water pipe, apply a low DC voltage that is lower than the electrolysis of water between the two electrodes, and deposit the substance that becomes the scale product on the cathode surface. The purpose is to keep the liquid part clean at all times.

Various types of devices for removing scale and the like have been proposed, and one example of a recent electric water treatment device will be described with reference to FIG. Reference numeral 3 denotes an electrical section, in which power supply components (not shown) and the like are housed within the molded body 4. Reference numeral 5 denotes an electrode connection conductor embedded in the protrusion 6 of the molded body 4, and is connected to the anode 1 via a flexible conductor 10.

The cathode 1 has a monogonal shape and is made of titanium plated with platinum, and one end (the upper end in the figure) fits into the protrusion 6 of the molded body 4. Further, a mounting seat 11 is provided near the upper end of the anode 1 in the figure, and is connected to the protruding seat 6 by a flexible conductor 10 made of platinum plating.

Reference numeral 2 denotes a cathode made of a galvanized steel tube or a stainless steel tube, which is integrally connected to the electrical section 3 by a mounting bolt 9 via a 7 flange 8 provided at one end (the upper end in the figure). In addition, conduits 12 and 13 are provided near both ends (upper and lower ends in the figure) of the cathode 2, each having seven flanges 14, which serve as an inlet and an outlet for treated water. It is attached to a part of the channel so that treated water flows inside the cathode 2. A cover plate 15 is provided at the lower end of the cathode 2 in the figure, and is configured to hold and fix the lower end of the anode 1 via an insulator 7 made of synthetic resin. A drain hole 16 is provided at the lower end of the cathode 2 in the figure, and a washer 17 which also serves as a ground terminal is provided.
A bolt 18 inserted through is screwed.

The recent electric water treatment equipment constructed as described above consists of double cylindrical electrodes (the inner tube is the anode, the outer tube is the cathode), and a direct current is passed between the electrodes (for example, the current density is 4X10″
6A/cm2), scale is removed by applying an electrostatic effect to the water containing scale etc. passing between the electrodes or by an oxidation-reduction effect.

(Problems to be Solved by the Invention) However, in the conventional electric water treatment equipment as described above, the electrodes are each cylindrical, and the single-WIViA
Therefore, the flow path formed in the water treatment device is
This is a limited portion formed between the inner surface of the anode 2 and the outer surface of the anode 1, and the cross-sectional area of the channel becomes small, and the resistance of the channel becomes large. Further, the cross-sectional area of the flow path becomes smaller due to the scale deposited on the cathode 2.

This problem of flow resistance can be solved by making the anode 1 smaller in diameter or by making the cathode 2 larger in diameter, but in the former case the device becomes larger, and in the latter case, the cathode 1 and cathode 2, and since water is present between the two electrodes, the resistance between the two electrodes becomes even greater, and Joule heat loss increases.
There is a problem in that the applied electrical energy is consumed not for scale prevention or scale precipitation, but for increasing the water temperature, resulting in a decrease in efficiency.

Furthermore, if a large amount of scale or other inorganic organic substances adheres or precipitates to the cathode 2 due to electric force, or if it adheres to the cathode 2 for some reason not due to electric force, the cross-sectional area of the flow path decreases, and Because the current density of the scale becomes smaller and the scale precipitation efficiency decreases, it is necessary to remove this scale. Conventionally, this was done by increasing the flow rate of water or physically removing the scale, but The efficiency is not satisfactory (also, temporarily
There is a problem with having to stop for cleaning.

(Means for Solving the Problems) The present invention has been made in order to eliminate the drawbacks of the conventional electric water treatment equipment described above, and is an electric scale that efficiently prevents or precipitates scale components in water. The object of the present invention is to provide a removed water treatment V device.

Another object of the present invention is to provide a scale treatment method characterized by efficiently removing scale deposited on an electrode.

The present invention provides a tubular container body having an inlet for water to be treated and an outlet for treated water, and at least one pair of yin and yang, which are provided parallel to each other at regular intervals along the longitudinal direction of the container body. The present invention provides an electric scale removal water treatment device comprising an electrode and a positive/negative current switching device connected to both the positive and negative electrodes.

The present invention also provides a tubular container body having an inlet for water to be treated and an outlet for treated water, and at least a pair of Yin-Yang and Yin-yang tubes provided in parallel with each other at regular intervals along the longitudinal direction of the container body. In a water treatment device consisting of an electrode, the water to be treated is made to continuously flow into the container main body through the inlet and flowed out through the outlet, while the positive and negative currents are alternately switched intermittently to generate both the currents. The present invention provides an electric scale removal water treatment method characterized by applying electricity to the water.

Next, the apparatus of the present invention will be explained in detail with reference to the drawings. FIGS. 2 and 3 are external views showing an example of the apparatus of the present invention. That is, the container main body 31, which has a cylindrical shape such as a circular, oval, or square cross section, is provided with a treated water inlet 33 and a treated water outlet 34. (not shown)
is stored. Further, an ff1ffl terminal storage case 32 is attached to the flange portion 30 at the end thereof. The inlet 33 is attached to a part of a pipe line in a boiler or cooler, etc., so that water to be treated flows through the apparatus of the present invention.

FIG. 4 is a front view showing an example of the electrode storage box, and FIG. 5 is a sectional view showing an example of the electrode storage box.

In the figure, one end of the electrode storage box 52 has a flange portion 5.
3 is provided. These materials are insulating materials such as polyethylene, polypropylene, polyvinyl chloride,
I! of polyvinylidene chloride, polystyrene, ABS resin, nylon, fluororesin, methacrylic resin, phenol m fat, etc. Those coated with oil or the above-mentioned resins are used. In this electrode storage 1i52, at least two electrodes 51, preferably a plurality of anodes and cathodes, are installed in parallel alternately at predetermined intervals. The shape of the electrode 51, that is, the anode and the cathode, is a plate shape, a plate shape with a large number of through holes, or a mesh shape. The material of the electrode may be carbon-based, Fe-Ni, Fe-Ni-C, stainless steel, lead-based, platinum-based, etc., but Fe-N is preferable.
i, Fe-Ni-Cr stainless steel and platinum,
Iridium, platinum-iridium systems, and especially platinum-coated titanium steel systems are suitable. The electrodes are installed in parallel at a predetermined interval, but the interval between the electrodes is 0.
．． 5 to 2°Qc+e, preferably 0.8 to 1.5 CI.

The electrodes, that is, the anode and the cathode, are each connected to an external power supply section to receive power supply.

The current value is less than that of water electrolysis. Furthermore, the water to be treated passes between the electrodes 51 to remove scale.゛The electrode housing 152 is located between the inlet 33 and the outlet 3 of the main body 31.
It is stored between 4. As shown in FIG. 4, a disc-shaped seven flange portion 53 is attached to one end of the electrode storage box, and the electrode storage box is fixed within the main body 31 by this disc-shaped seven flange portion 53.

FIG. 6 is an installation diagram of an example of electrodes used in the present invention.

In the figure, electrodes (not shown) are communicated with a connector 47 by a flexible conductor 49. connector 47
are O-ring 46, plastic pedestal 44, O-ring 467 flange 45, plastic pedestal 44, copper wire 41
and is fixed by a nut 42 via a bolt 43. The connector 47 and the flange 45 are insulated via an insulating ring 48. 7 langes 45 are fixed with bolts and nuts. The conducting wire 41 is connected to a power source via a positive/negative current switching device (not shown).

FIG. 7 is an electrical connection diagram showing an example of a positive/negative switching device connected to a DC power source used in the present invention. In FIG. 7, ■θ indicates a DC power supply, and 65 indicates an electric scale removal water treatment device. 60 is a switch, 61.62 is an I
It is a Fi1m device, such as an electromagnetic switch, an electromagnetic contactor,
It is electromagnetic relay electricity.

63 and 64 are timers, such as electronic type, motor type,
It is an air type timer.

1.7JV of electrode! In other words, the positive and negative electrodes can be set manually or by programming.

In FIG. 7, when the switch 60 is turned on, the timer 63
, the opening/closing device 61 is operated and the electric power is applied to the electric scale removal water treatment device 65. When the timer 63 is turned off after a certain period of time, the timer 64 and the opening/closing device 62 are activated, and the electric power is applied to the electric scale removal water treatment device 65 in the opposite direction. This operation is repeated by a combination of a timer and a switchgear.

FIG. 8 is a flow sheet showing an example in which the apparatus of the present invention is used. That is, the descaled water supplied from the scale collector 21 to the cooling tower 22 via the line 26 is
After being cooled in the cooling tower 22, it is supplied to the heat exchanger 24 (or refrigerator) by the circulation pump 27, then sent to the electric scale removal water treatment equipment f120, and deposited in this electric scale removal water treatment equipment 20. The treated water from which scale has been removed is sent to a scale collector 21 where the scale is collected and discharged through a line 27, and the treated water is circulated through a line 26 to a scale cooling tower 22. In addition, the insufficient water is replenished as make-up water from the line 25.

The apparatus of the present invention is intended for water used in various water supply and distribution facilities such as cooling water, hot water, building water supply, water supply, and solar thermal systems.

That is, the water has a temperature of 5.0-80-0°C, a pH of 5.8-10.0, and a total hardness of 15.0-2000. C) +a/IM Fulkari 20. O~600. Otag/l.

Evaporation residue 5000. Omu/4 or less 1 io of salt>
800. OrgO/1 or less Electric conductivity 80.0
-7000.0μs/cm, preferably Water temperature 10.0-50.0℃ pI-15.8-8.6 Total'ila 30.0-1500.0I1g//
! M full l J 30. O~400.0ma/1 Evaporation residue 2000. OraQ/(hereinafter referred to as chlorine ion)
600. Ovaa/1. Electric conduction below: $80.
The object is water exhibiting properties of 0 to 3500.01 ls/are.

Further, the speed at which the water to be treated passes through the electric scale removal water treatment device, that is, the speed at which the water to be treated passes between the anode and the cathode is 0.5 to 1.5i/sec.

Preferably it is 0.5 to 1.0 Il/sec.

(Example) FIG. 9 is a diagram showing the relationship between the scale precipitation rate and the scale peeling rate with respect to the flow rate, and has the following properties in the flow sheet of FIG. 8.

Water m 18℃ pt:
8, 4 total stool level 1140
mQ/1°M alkali 260Il1g/l distillation residue 1980mMI.

Chlorine t > 520 ray/Il Electrical conductivity 3300 us/am water is introduced into the circulation system and circulated by the circulation pump 27, the heat exchanger 24 and the cooling water tower 22 are operated, and the initial settings are made in the electric scale removal water treatment device. 3.6iA1012 11F flow in one direction,
A scale removal precipitation curve was obtained. In FIG. 9, a scale precipitation rate of 100 means a scale thickness of 2.011/II, and the precipitation time at each flow rate was 72 hours.

Further, the scale peeling curve is a scale peeling curve obtained when a scale having a thickness of 21/II is obtained on the cathode and is peeled off by the action of each flow rate without applying electricity.

The peeling time at this time was constant at 360R. Also, flow rate 1
, 5 m 7 sec or more indicates a dangerous flow velocity region from a physical and scientific point of view.

FIG. 10 is a diagram showing the relationship between peeling rate and time for a specified flow rate, and in FIG. Obtain Ora/m's,
After that, the direction of application was reversed, and the scale peeling rate was examined. In FIG. 10, the target separation (80% or more) is reached at a flow rate of Q of 511/Sec at approximately 2.5%.
5 hours, whereas in the case of peeling due to the effect of flow velocity (see Figure 9), it is about 17% in 360 hours, and there is a clear difference in soaking level.

Fig. 11 is a diagram showing the change in current value over time when electricity is applied in one direction in the electric scale removal water treatment device shown in Fig. 8, and 0 on the vertical axis in the figure is 3.6 ta A/cm2. .1
00 indicates ImA/cm2, and as the current value decreases, the ability to deposit scale decreases significantly.

FIG. 12 is a diagram showing the rate of change in current when the current direction is temporarily changed (for 3 hours) using a stationary electrode in the electric scale removal water treatment apparatus in FIG. Temporarily changing the current direction (for 3 hours) with fixed position electrodes means once every 10 days (
This means changing the direction of current flow at a rate of >3 hours, and then returning it to the original state.Alternate regular switching means switching the direction of current flow once every 10 days. In this case, a platinum-coated stainless steel plate was used as the electrode. Switching of the current direction changes depending on the water quality, but it may be stopped, irregular, or preferably fixed. The switching is performed every 3 to 15 days, preferably every 5 to 10 days.

(Effects of the Invention) As is clear from these experimental results, when the electric scale removal water treatment device according to the present invention is used and the scale removal method is implemented, extremely satisfactory results are obtained in terms of scale precipitation and prevention effect. was gotten.

(1) By alternating the current direction during operation, especially at regular intervals, scale deposited on the electrode surfaces can be peeled off, keeping both electrode surfaces clean at all times and stabilizing the current density between each electrode. At the same time, scale removal ability such as scale prevention and scale precipitation is improved.

(2) By changing the direction of current flow, it is possible to extend the life of the electrode.

(3) By using multiple electrodes, it is possible to stabilize the voltage between each electrode, reduce the spacing between each electrode, suppress the generation of Joule heat, and enable higher density current to flow. The flow path area is also large, which improves scale prevention and scale precipitation ability.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of the main parts of a conventional electric scale treatment device, Figures 2 and 3 are external views of the main body of the electric scale removal water treatment device of the present invention, and Figure 4 is the electric scale removal water treatment of the present invention. A front view of the electrode storage box installed inside the box, Figure 5 is the V- in Figure 4.
6 is a sectional view along Va, FIG. 6 is an electrode installation diagram, FIG. 7 is an electrical connection diagram showing an example of switching the DC power supply used in the present invention, and FIG. 8 is an electric scale-removed water 51! Figures 9 to 11 are flowsheet diagrams incorporating the LL process equipment, and Figures 9 to 11 are diagrams showing the experimental results of examining the scale precipitation effect, scale peeling effect, and current change rate using the method according to the present invention. It is a figure which investigated the current change rate in an invention method. 31...Electric scale removal water treatment equipment main body, 51...
·electrode. Patent applicant: Fusamori Kogyo Co., Ltd. (Figure 2, Figure 31! 1, 4th Figure, Figure 6, Figure 9, 1%)

Claims (4)

[Claims] (1) A tubular container body equipped with an inlet for water to be treated and an outlet for treated water, and at least one pair of yin and yang, which are provided parallel to each other at regular intervals along the longitudinal direction of the container body. An electric scale removal water treatment device comprising an electrode and a positive/negative current switching device connected to both the positive and negative electrodes. (2) The electric scale removal water treatment device according to claim 1, wherein a plurality of pairs of negative and positive electrodes are provided. (3) A tubular container body equipped with an inlet for water to be treated and an outlet for treated water, and at least one pair of negative and yang electrodes provided parallel to each other at regular intervals along the longitudinal direction of the container body. The water to be treated is made to continuously flow into the container main body through the inlet and flow out through the outlet, and during that time, the positive and negative currents are alternately switched to the two electrodes. An electric scale removal water treatment method characterized by applying electricity. (4) The electric scale removal water treatment method according to claim 3, wherein the positive and negative currents are switched at regular intervals at regular intervals.