JP2007021325A - Calcium based scale prevention device and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device to prevent the phenomenon that a calcium component in the drain is made into scale, and is stuck to equipment, in equipment where leaked water from concrete collected in a dam inspection gallery or the like is drained to the environment. <P>SOLUTION: The calcium based scale prevention device 100 installed in a drainage pit 1 for leaked water from a concrete structure is provided with: a woody distributing pipe 12 as a means of electrifying drainage so as to be negative by magnetism whose outer circumference is provided with a permanent magnet 11; a woody lattice rack 21 and/or a bubbler 31 as a means of subjecting drainage to air oxidation which is located at the preceding stage or trailing stage of the electrifying means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is installed in a drainage facility that temporarily collects and discharges wastewater containing calcium leaked from a concrete structure such as a dam embankment or a foundation ground such as a concrete grout, where the calcium-based scale adheres. It is related with the apparatus which prevents. More specifically, the present invention relates to an apparatus for preventing calcium-based scale from adhering to a pump or a VP (vinyl chloride) pipe in the drainage facility. The present invention also relates to a method for preventing calcium-based scale using the apparatus.

  The concrete dam body constructed by the streamlined construction method such as RCD method and ELCM method, and the concrete grout built for the improvement of the foundation ground of the dam, water containing a lot of calcium, which is a raw material for cement, is connected. Leak from etc. Leakage of calcium is particularly noticeable at the beginning of dam construction. The leaked water is drained pits shown in Fig. 6 through the passages provided inside the dam body to perform post-completion audits, various measurements, grout operations, gate operations, etc. It is collected in a drainage facility and released into the environment.

  A VP pipe or the like is connected to the outlet of the drain pit to guide drainage to the environment. In addition, an emergency submersible pump is installed in the drainage pit in order to cope with the flooding during floods. In these drainage facilities, a phenomenon occurs in which the calcium content in the drainage is deposited as a scale such as calcium carbonate, calcium silicate, and free lime. If the scale reduces the drainage capacity of the drainage facility and the adhesion is left for a long period of time, problems such as clogging or failure of the pump, blockage of the VP pipe, etc. occur.

  Conventionally, there are (1) an electromagnetic method, (2) a physical method, and (3) a chemical method as a countermeasure for the calcium-based scale. The method will be briefly described.

(1) Electromagnetic method using a coil A coil is wound around a tubular body through which drainage is passed, and a magnetic field is generated by passing an electric current therethrough. Magnetized waste water is less likely to generate calcium-based scale. Installation is easy, but the effect may be low depending on the water quality.

(2) Physical method
1.
Washing If a certain amount of fresh water can be secured, wash the scale by flushing with a fresh water pump during long-term suspension of use. Jet cleaning is used for the small piping at the end. Although it is a simple method, it is often difficult to ensure clean water, and wastewater treatment after washing becomes a problem.

2.
Draining This method drains all the water in the piping during long periods of inactivity. It is effective when used in combination with the above washing. It is necessary to newly provide a plurality of air holes and drain holes in the piping, and even if it is time to suspend long-term use, it may not be applicable to existing buried pipes.

3.
Ultrasonic method This method dissolves calcium by generating ultrasonic waves. Since no effect can be expected except at locations where ultrasonic waves are applied, it is necessary to apply ultrasonic waves to all locations.

(3) Chemical method
1.
Addition of calcium bicarbonate This is a method of adding calcium bicarbonate (Ca (HCO ₃ ) ₂ ). There is a risk of melting other heavy metals.

2.
Dissolution by carbon dioxide gas This is a method in which carbon dioxide gas is aerated from the bottom of the water tank and the scale is dissolved in water. Utilizing the fact that CaCO ₃ dissolves when carbon dioxide gas is injected excessively. It is necessary to pay attention to oxygen deficiency in the work of injecting carbon dioxide. It is also necessary to keep the carbon dioxide cylinder at 40 ° C. or lower without exposing it to direct sunlight.

3.
Use of drug A method using a calcium-based scale inhibitor. The scale inhibitor, as a dispersant, prevents fine crystals made of calcium from growing or agglomerating and depositing. It can be said that it is a relatively simple method by injecting a scale inhibitor into the pipe during a long-term suspension of use. Some drugs can adversely affect downstream waters. In addition, organic drugs cause the problem of increased COD.

  Each of the above methods has advantages and disadvantages, and at present, no effective calcium-based scale countermeasures have been taken against leakage water from concrete structures. Therefore, an object of the present invention is to provide a device that prevents the calcium content in drainage from adhering as a scale to facilities that discharge concrete leakage collected from a dam inspection gallery to the environment. is there.

  As a result of intensive studies on the above problems, the present inventors have found that the above problems can be solved by negatively charging the wastewater and oxidizing the wastewater with air. That is, the present invention is a calcium-based scale prevention apparatus installed in a drainage facility for leaking water from concrete facilities, the means for negatively charging the drainage by magnetism, and the drainage located at the front stage or the rear stage of the charging means. And a means for oxidizing the air. The order of the magnetic charging means and the air oxidizing means is not limited, but preferably the magnetic charging means is installed upstream of the air oxidizing means.

  The magnetic charging means means that the waste water is negatively charged by passing the waste water through a magnetic field. Such drainage charging means is preferably composed of a wooden water distribution pipe having a magnet attached to the outer periphery thereof. Since the wooden water distribution pipe is electrically neutral, the state of the negatively charged drainage can be maintained.

  In the apparatus of the present invention, the scale is hardly precipitated by lowering the pH of the wastewater by air oxidation of the wastewater. Such air oxidation means preferably comprises means for dropping the waste water onto at least one stage of wood lattice rack and / or at least one bubbler. When the wastewater falls and collides with the wooden lattice net shelf, the mixed oxidation of the wastewater using the potential energy and the atmosphere is promoted. On the other hand, the bubbler is buried in the stored water in the drain pit, and the air emitted from the bubbler promotes air oxidation of the drainage.

  It is preferable to enclose the rising path of the bubbles released from the bubbler with a wooden frame.

  In the calcium-based scale prevention apparatus of the present invention, it is desirable to install a Langeria index evaluation means in the vicinity of the entrance and / or exit of the drainage facility. The Langeria index calculated by the evaluation means is a material for determining the possibility of calcium-based scale precipitation. The index can also be used as a measure of oxidation by the air oxidation means.

(ただし、上記式は２５℃の値であって、温度1℃上昇に対してランゲリア指数は1.5×10^-2増加する)
によって求めることができる。 The Langeria index is calculated from the following formula (1) based on the Ca ion concentration, water temperature, pH, total alkalinity, and soluble substance amount:

(However, the above formula is a value of 25 ° C, and as the temperature increases by 1 ° C, the Langeria index increases by 1.5 × 10 ^-2 )
Can be obtained.

  Therefore, in this specification, the Langeria index evaluation means means all evaluation means that measure parameters such as pH and calcium ion concentration and convert them to the Langeria index in addition to measuring the Langeria index.

  When the Langeria index evaluation means is installed in the vicinity of the drainage facility entrance, the Langelier index of the wastewater is estimated from the evaluation value, the possibility of attachment of the calcium-based scale is determined from the obtained Langeria index, and the air oxidation means is further determined. Can provide feedback.

  When the Langeria index evaluation means is installed in the vicinity of the drainage facility outlet, the drainage Langelia index is estimated from the evaluation value and fed back to the air oxidation means so that the value falls within a predetermined range.

  The calcium-based scale preventing apparatus of the present invention can be installed in a drainage pit for collecting and discharging calcium-containing wastewater leached from, for example, a dam bank or grout via a corridor.

  The present invention is a calcium-based scale prevention method for drainage facilities of concrete structure leakage water, the step of negatively charging the wastewater by magnetism, and the step of air oxidizing the wastewater before or after the drainage charging step The calcium-based scale prevention method is also provided. The order of the magnetic treatment and the oxidation treatment is not limited, but the oxidation treatment is preferably performed after a negative charging treatment by magnetism.

  In the drainage charging step, the drainage is preferably passed through a wooden water distribution pipe having a magnet attached to the outer periphery thereof.

  Preferably, the step of oxidizing the wastewater by air comprises a step of dropping the wastewater into at least one stage of wood-based dredging and / or a step of bubbling the wastewater in the facility with at least one bubbler. In the present invention, bubbling is used in the same meaning as aeration or aeration. Air oxidation is used to include oxygen-enriched air.

  It is preferable to enclose the rising path of the bubbles released from the bubbler with a wooden frame.

  The Langeria index evaluation means provided in the vicinity of the entrance and / or exit of the drainage facility can be used to evaluate the Langeria index, and the degree of oxidation in the air oxidation process can be adjusted according to the Langeria index.

  The Langeria index can predict the form from calcium deposition to corrosion. Preferably, the degree of oxidation in the air oxidation step is adjusted so that the Langeria index at the outlet of the drain pit is between 0 and 0.6. Although it depends on the parameter of the formula (1), generally, if the pH is lower than 9.3, the Langeria index also decreases to 0.6 or less. When the index is in the range of 0.6 to 1.0, the amount of precipitation on the scale is slight. When the Langelia index is 1.0 or more, Ca oxide adheres to the pipe wall, which hinders maintenance of drainage facilities. When the Langelia index is less than 0, calcium does not precipitate, but it becomes corrosive and corrodes the tube wall of metals. Therefore, controlling the Langeria index to 0 to 0.6 is desirable in terms of protecting the metal pump, the VP pipe, and the like from both adhesion and corrosion of the calcium-based scale.

  A pump or VP pipe, which is a place where a conventional calcium-based scale adheres, is electrically negatively charged. The waste water negatively charged by the magnetic charging means of the device of the present invention repels the inner surface of the pump and the inner surface of the VP pipe, and the calcium-based precipitates in the waste water are difficult to adhere. The air oxidation means of the apparatus of the present invention can bring the pH of the wastewater to the oxidation side, and thereby the Langeria index, which is an indicator for the scale adhesion of the wastewater, can be kept within a slight range of scale generation. The device of the present invention steadily prevents the calcium-based scale from adhering by expressing the above two actions simultaneously.

  A powerful and large-scale air oxidation means (for example, a bubbler) is required to bring the Langeria index to a range where the calcium-based scale does not occur by installing the air oxidation means alone in the drainage facility. On the other hand, the apparatus of the present invention can be made compact by combining the magnetic charging means and the air oxidation means, and the equipment cost is reduced. It can also be installed in a limited space in the drainage facility.

  The maintenance management of the entire drainage facility including the apparatus of the present invention requires only periodic inspections for equipment and other simple maintenance, and the maintenance cost is very low.

  In particular, the apparatus of the present invention is a drainage facility that collects and discharges calcium-rich water leaking from a concrete structure such as a dam embankment constructed by a rationalized construction method, a foundation ground constructed with a large amount of concrete grout, etc. Is ideal for preventing calcium-based scales from forming and adhering to drainage pumps and VP pipes.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1A-C show a calcium-based scale prevention apparatus 100 according to a first embodiment of the present invention. The scale prevention device 100 is installed in a drainage pit 1 that collects and receives leaked water from a dam bank or grout through a corridor. The drainage pit 1 has a drainage pit inlet 2 and an outlet 3, a submersible pump 4 that operates during a flood, and a VP pipe 5 that extends from the drainage pit outlet 3 for always discharging the drainage, as in the conventional case (FIG. 6). Is provided.

  In the calcium-based scale device 100 of the present invention, a wood-based water distribution pipe 12 having a magnet 11 mounted on the outer periphery thereof is mounted in the vicinity of the drain pit inlet 2 in a state of being inclined downward. The magnet 11 is fixed to the wooden water distribution pipe 12 with metal fittings. Thus, the water pipe 12 to which the magnet 11 is attached constitutes a part of the apparatus of the present invention as means for negatively charging the leaked water collected through the passageway by magnetism.

  The operation of the magnet 11 will be described. A magnetic field is generated in the water distribution pipe 12 by the magnet 11. And if drainage passes across this magnetic field, the drainage will be negatively charged by the law of electromagnetic induction. Negatively charged drainage is a drainage pump 4 (casing suction port is electrically negatively charged) and VP pipe 5 (inner surface is electrically negatively charged), which is a place where calcium-based scale is easily attached. Repels electrically. Negative charging continues for about 60 minutes. Since the average storage time of the drainage pit is 20 minutes, the negative charge of the drainage is maintained until it passes through the VP pipe 5 from the drainage pit inlet 2.

  The magnetic flux density of the magnet 11 may normally be 1 to 12 kG, preferably 3 to 6 kG. As the magnet 11 having such a magnetic flux density, a neodymium permanent magnet is employed in FIG. 1A. Other examples of permanent magnets include alnico, ferrite, samarium cobalt and neodymium ferrite boron. Permanent magnets are advantageous in that they do not require maintenance.

  In the permanent magnet installation method, a pair of permanent magnets divided into two are assembled so that different poles face each other, and the wooden water distribution pipe 12 is installed between the combined magnet sets. A plurality of sets of permanent magnets may be laminated so that adjacent pairs of opposing surfaces have different polarities.

  The magnet 11 used in the calcium-based scale device of the present invention may be an electromagnet such as a solenoid coil in addition to a permanent magnet.

  The wooden water distribution pipe 12 is advantageous in that it does not affect the electrical state of the negatively charged waste water when passing through the magnetic field by the magnet 11. Examples of wood types include bamboo (FIGS. 1A and 1B), wood, chip processed products, and the like. Bamboo is particularly preferable in terms of processability to the water distribution pipe, strength, durability, and the like.

  The calcium-based scale device 100 of the present invention further includes a wooden lattice net shelf 21 that receives drainage flowing down from the water distribution pipe 12 immediately below the outlet of the wooden water distribution pipe 12 and above the water storage level of the drainage pit 1. (Fig. 1C).

  This wooden lattice net shelf 21 functions as a means for air oxidizing the waste water of the apparatus 100 of the present invention. That is, when the waste water falls on the wooden lattice net and collides with the wooden lattice net 21, mixed oxidation of the waste water and the atmosphere using the potential energy is performed. Since the wooden lattice net shelf is permanently installed, it is particularly effective when the below-described bubbler is stopped.

  The wooden lattice net shelf 21 may be of a bowl shape (FIG. 1C) or a net shape. The material of the lattice net shelf may be the same as that of the wooden water distribution pipe 12, but bamboo is preferable in terms of workability to the lattice network, strength, and durability (thus, bamboo basket is used in FIG. 1).

  The hole diameter and number of the wooden lattice net shelf are not particularly limited as long as they do not affect the maximum amount of drainage. For example, 100 or more 3-5 mm square holes are provided.

  The wooden lattice net shelf 21 is usually stacked in 1 to 10 stages, preferably 2 to 5 stages, particularly preferably 3 to 4 stages. Increasing the number of steps increases the chance of collision with drainage and hence oxidation. The multistage lattice net shelf 21 is usually placed on a stainless steel frame.

  A first bubbler 31A is installed in the vicinity of the wooden lattice net shelf 21 and below the water storage level of the drain pit. The bubbler 31A functions as a means for air-oxidizing the waste water of the apparatus 10 of the present invention, like the lattice net shelf 21.

  The shape of the bubbler is not particularly limited. The bubbler may be an air diffuser having a plurality of holes formed in a line on the side surface of a cylinder whose tip is sealed as shown in FIG. What is necessary is just to adjust the hole diameter of a diffuser tube so that the bubble diameter obtained may be set to 100-1000 microns, Especially preferably, it is 200-300 microns.

  One end of the bubbler 31A is connected to an air supply source 35 such as a pump, a blower, a compressor, or a cylinder through an air pipe 32. From the source, air or oxygen-enriched air is sent constantly or intermittently. A valve 33 is attached in the middle of the pipe 32, and the amount of air to be supplied can be controlled manually or automatically.

  Above the bubbler 31A, a wooden frame 34A is erected so as to surround the ascending path of bubbles released from the bubbler. This wooden frame 34A is effective in securing an opportunity for air oxidation by bubbling and enhancing the effect. The material of the wooden frame is not particularly limited, and examples thereof include paulownia (FIG. 1).

  In the vicinity of the drain pit outlet 3 in FIG. 1A, a second bubbler 31B and a wooden frame 34B are installed above it. By installing the second bubbler 31B, air oxidation of the waste water is surely performed.

  The wooden frame 34A installed above the first bubbler 31A and the wooden frame 34B installed above the second bubbler 31B are usually metal fittings, bolts, etc. (not shown) in order to prevent floating from the water. ). Further, notches (not shown) for releasing the drainage are provided on the side surfaces of the wooden frames 34A and 34B from the top to the bottom.

  A method for using the calcium-based scale preventing apparatus 100 of the present invention will be described below. First, leaked water rich in calcium leaked from the dam body and the concrete grout is guided to the wooden water distribution pipe 12 of the drainage pit 1 through a passage not shown.

  The drainage is passed through a magnetic field created by a magnet 11 mounted on the outer periphery of the water distribution pipe 12. The drainage is negatively charged according to the magnitude of the magnetic field and the drainage speed. The charged state of the waste water can be known by measuring the electrostatic potential.

  The submersible pump 4 and the VP pipe 5 where the conventional calcium-based scale adheres are electrically negatively charged. Therefore, the negatively charged drainage repels the inner surface of the drainage pump 4 and the inner surface of the VP pipe 5, and calcium-based precipitates in the drainage hardly adhere to the submersible pump 4 and the VP pipe 5.

  The negatively charged waste water is dropped onto a wooden lattice net shelf 21 (three stages in FIG. 1) while maintaining an electrical state through an appropriate wooden distribution pipe. When the wastewater falls and collides with the wooden lattice net shelf 21, oxidation is performed by mixing the wastewater using the potential energy and the atmosphere. Due to the air oxidation of the wastewater by the wooden grid net shelf 21, the pH of the wastewater is lowered. When the pH of the waste water is lowered, the Langeria index is also lowered, and it is difficult to produce a calcium-based scale.

  The drainage that has passed through the wooden latticed shelf network 21 falls into the drainage pit 1 and thereafter undergoes bubbling by the first bubbler 31A. Since the drainage channel and the bubbling area are surrounded by the wooden frame 34A, a long bubbling period is ensured. This bubbling further promotes air oxidation of the waste water. Due to the negative charge of the waste water and air oxidation, the calcium-based scale is prevented from adhering to the submersible pump 4 in the pit.

  The drainage is further bubbled by the second bubbler 31B in the vicinity of the drainage pit outlet 3. This bubbling further promotes air oxidation of the waste water. Due to the negative charge of the waste water and further air oxidation, the calcium-based scale is prevented from adhering to the VP pipe 5 connected to the drain pit outlet 3.

  FIG. 2 shows a calcium-based scale prevention device 200 according to a second embodiment of the present invention. The scale prevention apparatus 200 has the same configuration as that of the first embodiment except that only the lattice net shelf 21 is used as the air oxidation means of the apparatus 100 of FIG. 1 (that is, the first and second bubblers are not installed). . In FIG. 2, the same reference numerals as those in FIG. 1 retain corresponding functions.

  The calcium-based scale prevention apparatus 200 is reduced in equipment cost and maintenance cost as compared with the apparatus of FIG. This embodiment is a calcium-based scale, such as when the number of days after the construction of a concrete dam and the amount of leaked water from the concrete structure is small, the scale of the concrete structure is small, or the amount of calcium in the leaked water is small. This is useful when the problem is minor.

  FIG. 3 shows a calcium-based scale preventing apparatus 300 according to the third embodiment of the present invention. The prevention device 300 has the same configuration as that of the first embodiment except that only the first bubbler 31A and the second bubbler 31B of the device 100 of FIG. 1 are used (that is, the wooden lattice net shelf 21 is not used). is there. This device is also useful when the calcium-based scale adhesion problem is relatively minor. In FIG. 3, the same reference numerals as those in FIG. 1 hold corresponding functions.

  FIG. 4 shows a calcium-based scale prevention device 400 according to a fourth embodiment of the present invention. The scale prevention apparatus 400 is further provided with a Langeria index evaluation means 41 in the vicinity of the drain pit inlet 2 in the apparatus 100 of the first embodiment. The Langeria index evaluation means 41 is a means for calculating the Langeria index by measuring at least one of parameters including pH, water temperature, calcium ion concentration, alkalinity, and the like. If some parameters are stable depending on the situation, only the changing parameters need be measured.

  The Langeria index evaluation means 41 calculates the Langeria index of the wastewater entering the drainage pit 1 and further determines the degree to which calcium-based scale is precipitated from the wastewater. If it is predicted that the calcium-based scale adheres to the pump or VP pipe, the means instructs the opening and closing of the valve 33 (for example, a solenoid valve), and the first and / or second bubbler 31 The oxidation ability can be adjusted.

  FIG. 5 shows a calcium-based scale prevention device 500 according to a fifth embodiment of the present invention. The scale prevention apparatus 500 is further provided with a Langeria index evaluation means 41 in the vicinity of the drain pit outlet 3 in the apparatus 100 of the first embodiment. The Langeria index evaluation means 41 calculates the Langeria index of the drainage discharged from the drainage pit, and determines the degree to which the calcium scale is deposited on the VP pipe. Further, when precipitation of calcium-based scale is expected, the oxidation ability of the first and / or second bubbler 31 is adjusted to the valve 33 (for example, a solenoid valve) so that the Langelia index is within a predetermined range, preferably 0 to Work to keep it at 0.6.

  Hereinafter, the present invention will be described in more detail based on examples and comparative examples. The following examples do not limit the invention.

[Example 1]
1 is installed in a dam drainage pit 1 having the specifications shown in Table 1. Table 2 shows the specifications of the apparatus 100.

１）排水ピット流入部、堤体外排出前ともに同形状である。

1) The shape is the same at the drain pit inflow and before discharge from the bank.

  Table 3 shows the physical property values of the waste water after passing through the scale prevention device 100 of the present invention. When the electrostatic potential of the wastewater that passed through the magnet was measured, a value of -250 to -350 mV was obtained. Ca in the drainage and drainage equipment such as drainage pumps and VP pipes were electrically repelled, and the water quality was less likely to adhere to Ca. Further, the pH of the wastewater dropped from 9.99-9.97 before treatment to 9.54 after the first bubbler and 9.32 after the second bubbler. As the pH decreased, the Langeria index (calculated from pH, temperature, calcium ion concentration) decreased from 1.2 to 0.5. When the inner surface of the VP tube was observed, the calcium-based scale did not adhere even after 90 days.

[Comparative Example 1]
The state of adhesion of calcium-based scale in the conventional drainage pit shown in FIG. 6 was investigated. The specifications of the drain pit are the same as those in the first embodiment. The evaluation results are shown in Table 3. When the leaked water of the dam was stored and drained in the drain pit, a scale was visually recognized on the inner surface of the VP pipe after 30 days. Thereafter, the scale adhesion gradually progressed little by little.

When the component analysis of the scale (EPMA analysis by EPMA-1600 manufactured by Shimadzu Corporation) was performed, about 10% by weight of Ca which is a component of the concrete cement was included. Since there are many O and C contents in the deposit, it was estimated that the Ca contents existed in the form of CaCO ₃ .

[Comparative Example 2]
Only the same magnet as in Example 1 was installed in the conventional drainage pit shown in FIG. The results are shown in Table 3. Although the electrostatic scale of the waste water decreased negatively, it became difficult for the calcium-based scale to adhere to the pump and the VP pipe, but the calcium-based scale adhered to the 30-day operation.

１）第１バブラー後のｐＨ
２）第２バブラー後のｐＨ

1) pH after the first bubbler
2) pH after the second bubbler

  The calcium-based scale prevention device of the present invention prevents calcium from adhering to drainage facilities in concrete dams constructed by rational construction (RCD method, ELCM method) or in concrete dams constructed with a large amount of concrete grout to improve the foundation ground. Ideal for. Furthermore, the calcium-based scale preventing apparatus of the present invention is also useful for drainage countermeasures for calcium-containing leaked water in concrete structures other than dams, such as tunnels.

It is sectional drawing of the scale prevention apparatus according to 1st embodiment of this invention. 1B is a plan view of the apparatus of FIG. 1A. FIG. It is a partially broken enlarged perspective view of a circled portion of the apparatus of FIG. 1B. It is sectional drawing of the scale prevention apparatus according to the 2nd embodiment of this invention. It is sectional drawing of the scale prevention apparatus according to the 3rd embodiment of this invention. It is a top view of the scale prevention apparatus according to the 4th embodiment of the present invention. It is a top view of the scale prevention apparatus according to the 5th embodiment of this invention. It is sectional drawing of the conventional drainage pit.

Explanation of symbols

1 Drainage pit 2 Drainage pit entrance 3 Drainage pit exit 4 Drainage pump (for operation during flood)
5 VP pipe (for regular drainage)
DESCRIPTION OF SYMBOLS 11 Permanent magnet 12 Wood distribution pipe 21 Wood lattice net shelf 31A Bubbler 31B Bubbler 32 Air piping 33 Valve 34A Wooden frame 34B Wooden frame 35 Blower 41 Langeria index evaluation means

Claims (13)

A calcium-based scale prevention device installed in a drainage facility for concrete structure leakage water,
Means for negatively charging the waste water by magnetism;
The calcium-based scale preventing apparatus, comprising: means for oxidizing the waste water located upstream or downstream of the charging means with air.   The calcium-based scale prevention device according to claim 1, wherein the drainage charging means comprises a wood-based water distribution pipe having a magnet attached to the outer periphery thereof.   The calcium-based scale according to any one of claims 1 to 3, wherein the means for oxidizing the waste water by air comprises means for dropping the waste water onto at least one stage of a wooden lattice net and / or at least one bubbler. Prevention device.   The calcium-based scale prevention device according to claim 3, wherein a rising path of bubbles released from the bubbler is surrounded by a wooden frame.   The calcium-based scale prevention apparatus according to any one of claims 1 to 4, wherein a Langeria index evaluation means is installed in the vicinity of the entrance and / or exit of the drainage facility.   The calcium-based scale prevention device according to any one of claims 1 to 5, wherein the drainage facility is a drainage pit for collecting and discharging calcium-containing wastewater leaking from a dam body or grout through a corridor. . A method for preventing a calcium-based scale in a drainage facility for concrete structure leakage water,
A step of negatively charging the waste water with magnetism;
The calcium-based scale prevention method comprising: a step of air-oxidizing the waste water before or after the waste water charging step.   8. The calcium-based scale prevention method according to claim 7, wherein the drainage charging step comprises passing drainage through a wooden water distribution pipe having a magnet attached to the outer periphery thereof.   10. The method according to claim 7, wherein the step of oxidizing the wastewater by air comprises a step of dropping the wastewater onto at least one stage of the wooden lattice rack and / or a step of bubbling the wastewater in the facility with at least one bubbler. The calcium-based scale prevention method according to claim 1.   10. The calcium-based scale prevention method according to claim 9, wherein a rising path of bubbles released from the bubbler is surrounded by a wooden frame.   8. The Langeria index evaluation means provided near the entrance and / or exit of the drainage facility is used to evaluate the Langeria index and adjust the degree of oxidation in the air oxidation step based on the Langeria index. The calcium-based scale prevention method according to any one of 10.   Oxidation in the air oxidation step so that the Langeria index is evaluated by a Langeria index evaluation means provided near the entrance and / or exit of the drainage facility, and the Langeria index at the exit of the drainage pit is kept between 0 and 0.6. The method for preventing calcium-based scale according to claim 11, wherein the degree of is adjusted.   The calcium-based scale prevention method according to any one of claims 7 to 11, wherein the drainage facility is a drainage pit for collecting and discharging calcium-containing wastewater leaking from a dam body or grout through a corridor. .

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