JP2010221137A - System for preventing clogging of well - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for preventing the clogging of a well by applying a magnetic field to flowing water to bring a scale-causing substance to a state being unable to precipitate. <P>SOLUTION: The system for preventing the clogging of the well by applying magnetic treatment to flowing water includes a screen having fine water passing holes provided to the lower part to be embedded in the ground of its peripheral wall by drilling over the whole periphery thereof, a coil-shaped conductive part spirally extending along the surface of the screen in the longitudinal direction of the well to be integrated with the screen, and a power feed part for feeding power to the coil shaped conductive part, and is constituted so that the pitch of the coil shaped conductive part in the longitudinal direction of the well is made larger than the width of the coil shaped conductive part in the longitudinal direction of the well so as to form gaps between the adjacent coil parts of the coil shaped conductive part to allow them to communicate with the inside of the screen through the water passing holes, the surface of the coil-shaped conductive part is insulated and an electromagnetic field is formed inside or outside the well by passing an electric current through the coil-shaped conductive part to prevent the adhesion of a clogging causing substance in water to the screen. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a well clogging prevention system, and more particularly to a recharge type well clogging prevention system.

  As a well, the lower part of a single peripheral wall (or double peripheral wall) embedded in the ground is a screen composed of, for example, a plurality of support rods and a spiral rigid wire wound around it, and groundwater is pumped through this screen. In addition, in the recharge well, water is poured into the soil around the well (Cited document 1 or Patent document 2, paragraph 0002). As the structure of the screen, there are a perforated pipe type and a net / filter type in addition to the spiral type (Patent Document 3).

  Regardless of the type of screen, precipitates (scales) may adhere to the surface due to iron hydroxide, iron bacteria, etc. contained in underground water or injected water. If the scale adheres, the screen is clogged, which is a serious problem in well maintenance.

  However, in reality, such clogging prevention measures have hardly been taken. Substances adhering to the screen by brushing or high-pressure washing if the clogging due to scale is confirmed by checking the conditions inside the well with a camera, etc., periodically or when the well capacity declines Remove.

  Here, brushing is to scrape off substances adhering to the screen with a brush or the like (Patent Document 4). The high pressure cleaning is a method in which fresh water is sprayed onto a screen or the like at a high pressure to remove adhering substances while destroying them (Patent Document 5).

JP 2006-169867 A JP2000-080681 JP-A-2005-336822 JP 2005-307575 A JP-A-2005-58975 JP 2003-80108 A

  In the method using brushing or high-pressure cleaning, it is necessary to remove the device such as a submersible pump installed in the well once and stop using the well. In addition, a dedicated tool is required, and a large-scale operation such as preparing a device for lifting heavy objects is required. Accordingly, the burden on labor and cost increases.

  Moreover, as a simpler method, it is conceivable to stop water injection to the water injection well and eliminate substances that cause clogging with a pump. However, when the amount of substances causing clogging is large or deposited, the causative substances cannot be removed by washing with a pump.

  The present applicant has intensively studied this problem, and has come up with the idea of applying a technique that renders the scale-causing substance in the running water unprecedented by magnetic treatment. It is empirically known that when a magnetic field is applied to water containing a clogging cause substance (such as ions), the substance does not precipitate.

  It is already known that such a technique is applied to a water pipe. For example, the filter is installed outside the pipe wall with respect to a filter installation position of the water pipe including a pair of filters crossing the upstream side and the downstream side of the flow path. An electromagnetic field is generated by a magnet (bulk magnet) (Patent Document 6).

  However, this document does not particularly disclose how to apply the magnetic processing technique to wells, particularly wells with screens. For example, if it is considered that the filter installation location of Patent Document 6 corresponds to a well screen, a magnet is installed at an outside location of the screen. However, if a magnet is installed on the well cylinder as taught by Patent Document 6, it will be an obstacle when water passes through the screen. This is because, in the case of a well, the place outside the screen becomes a path for water.

  If a magnet is installed in the well portion above the screen, the problem of the magnet blocking the passage of water does not occur. However, this configuration can be applied only to the water injection process in which water goes from the inside of the well to the screen. Even in a well mainly recharged, it is necessary to pump water for a certain period of time in order to collect the clogging cause substances diffused from the well, and a well that cannot do so is not preferable for the surrounding environment.

The applicant intensively studied this problem and came up with a configuration in which a coil-shaped conductive portion was formed along the spiral screen of the well with a water-permeable gap (see FIGS. 19 to 21). According to this configuration, during the water injection process, the scale-causing substance indicated by black circles in FIG. 20 changes to particles that are difficult to precipitate, indicated by white circles in the same figure, due to the magnetic field of the coil, and passes through the screen. However, this configuration still has the following problems. 1stly, since the coil-shaped electroconductive part was comprised in the space | gap for water permeation | transmission, it is that the number of turns of a coil will decrease. Second, the magnetic flux density around the coil is much weaker outside the coil than inside the coil, so that the effectiveness of magnetic treatment cannot be expected when groundwater is sucked up from the area _Aout outside the well. . This is because it reaches a place (inside the coil) where a strong magnetic field is generated after passing through the screen. This point will be described with reference to the reference examples of FIGS.

  A first object of the present invention is to provide a system for preventing clogging of a well in which a causative substance of scale is not deposited on the surface of a material by incorporating a coil-shaped conductive part including a water passage gap in a screen. It is to be.

  The second object of the present invention is to provide a well clogging prevention system that can cope with both water injection and pumping by making the screen with a coil-shaped conductive portion double inside and outside.

  A third object of the present invention is to provide a well clogging prevention system in which a coil-forming conductor is incorporated so as not to cross a water-permeable hole so as not to lower the hole area ratio.

  A fourth object of the present invention is to form an electromagnet forming lead along a rigid wire constituting a screen, and to provide a well clogging prevention system having excellent hole area ratio and sufficient strength. Providing a suitable rigid wire.

The first means is
A system for preventing clogging of a well, which is a screen that allows water to pass through the lower part of a peripheral wall for burying in the ground,
The lower part of the peripheral wall is a double peripheral wall, and each peripheral wall is an inner screen and an outer screen,
Along each peripheral surface of each screen, there is provided a coiled conductive portion extending in a space for passing water between coil portions adjacent to each other in the longitudinal direction of the well, and having an insulating coating on the surface,
Furthermore, a power feeding unit that can feed power to each of the coil conductive parts is provided.

  The first feature of this means is that the coil-shaped conductive portion is wound around the peripheral surface of the well screen with a water passage gap. With this configuration, the coiled conductive portion can be incorporated into the screen in a compact manner. The coiled conductive part may be integrally attached to the screen (see FIG. 7), or the spiral screen itself may double as the coiled conductive part (see FIG. 15). The second feature of this means is that the screen including the coiled conductive portion is doubled inside and outside, and provided so that the coiled conductive portions can be individually energized. Accordingly, it is possible to prevent the scale from being deposited by energizing the inner coil-shaped conductive portion with respect to the coil water injection stroke and by energizing at least the outer coil-shaped conductive portion with respect to the pumping stroke.

  The “screen” has a water permeability hole and has a function of allowing groundwater to be separated from surrounding soil and pumped. Water-permeable holes are formed finely enough to exhibit this screen function. Further, it is desirable that the water-permeable holes are distributed almost evenly on the entire screen so that the substances causing clogging are dispersed. The screen may be formed of perforated pipes or nets, but a large number of rings (cross members) are attached to a plurality of support rods (vertical members) arranged in a columnar shape with a small gap, or a spiral shape. When a rigid wire is wound, the structure is strong and has a high hole area ratio.

  The “coiled conductive portion” has a function as a magnetic coil for generating a magnetic field around the entire screen. However, in the coiled conductive portion of the present invention, for example, a gap (V) that is a passage for water is formed between adjacent coil portions as shown in FIG. For this purpose, the length (P) of one pitch of the coiled conductive part may be made larger than the width (W) of the coiled conductive part in the same direction. The said space | gap (V) is connected to the inward of a screen via the water-permeable hole (22). The surface of the coiled conductive part is insulated. When the coiled conductive portion is attached as a separate body from the screen, it is desirable that the coiled conductive portion does not cross the water permeable hole. This will be described later. In this case, it is preferable that the distance from each water permeable hole to the coiled conductive portion is substantially constant. The coiled conductive portion is easy to manufacture when wound from the outside of the screen as shown in the example of the drawing.

The second means includes the first means, and the power feeding portion energizes both the inner coil-shaped conductive portion and the outer coil-shaped conductive portion, and at least one of the two coil-shaped conductive portions. It is designed to be able to reverse the direction of the current flowing through the current.

  In this means, the two coil-shaped conductive portions are energized simultaneously, and strong in either the inner coil-shaped conductive portion or the gap between the inner coil-shaped conductive portion and the outer coil-shaped conductive portion. A magnetic field is generated.

The third means has the first means or the second means, and the shape and arrangement of the water-permeable holes are designed so that the coiled conductive portion does not cross the water-permeable holes when viewed from the outside of the screen. It is characterized by that.

  As described above, the structure that allows water to pass through the gap of the coiled conductive portion includes a mode in which the coiled conductive portion is wound from above the screen regardless of the arrangement of the water permeable holes as shown in FIG. . However, in that case, the coiled conductive portion that crosses the water permeable hole is easily damaged by the pressure of the soil. In order to avoid such inconvenience, the present means arranges the water-permeable holes so that the coiled conductive portion does not cross the water-permeable holes when viewed from the outside of the screen (in the radial direction of the cylindrical screen). suggest.

The fourth means has the third means, and the screen is composed of a plurality of support rods extending in the longitudinal direction of the well and a coiled rigid wire wound around the outside or inside of the support rods. And
While forming each water permeable hole at both the upper and lower edges of the rigid wire and the left and right edges of the support rod,
A conductive wire having an insulated surface is provided as a coil-shaped conductive portion at the end opposite to the support rod among the inner and outer end portions of the rigid wire.

  As described above, in the structure in which the coil-shaped conductive part having a water passage gap is introduced into the screen so as not to cross the water-permeable hole, for example, as shown in FIG. A mode in which a tube is formed in the tube wall is also included. However, in this case, the aperture ratio of the screen is small. In view of this, the present means proposes to attach a coil-shaped conductive portion to a rigid wire wound around a plurality of support rods that are parallel to each other in a columnar shape. As a preferred embodiment, a rigid wire is connected around the support rod by welding, and a heat-insulated wire is bonded to the end of the rigid wire after the heat from the welding has cooled.

In this means, there is also a device in the place where the coiled conductive portion is attached to the rigid wire. Assuming that the annexed coiled conductive portion on the upper surface S _U or the lower surface S _L of the rigid wire 8, it is necessary to increase the gap of the conductor portions adjacent in order to ensure a certain degree of width of the permeability pore. As a result, the number of turns of the coiled conductive portion is reduced. Therefore, in this means, the coiled conductive portion is attached to one end (end opposite to the support rod) of the inner end and the outer end of the rigid wire. As a result, the resistance to earth pressure is increased, the hole area ratio can be kept high, and the number of turns of the coiled conductive portion can be increased.

The fifth means is a rigid wire suitable for the well clogging prevention system by the magnetic treatment of the flowing water described in the fourth means,
It has a long cross-sectional shape in one direction, and one end portion in the longitudinal direction is wide, and a fitting groove for inserting a conductive wire is formed in the middle portion in the width direction of this end portion over the entire length of the rigid wire.

  This means proposes a rigid wire suitable for use in the clogging prevention system. That is, since the conducting wire is fitted into the fitting groove for inserting the conducting wire over the entire length of the rigid wire, the conducting wire is unlikely to fall off the rigid wire.

According to the first aspect of the invention, since the coiled conductive portion including the water passage gap is introduced into the inner and outer double screens, the injected water or the ground water can be effectively magnetically treated.

  According to the invention relating to the second means, it is possible to select the state of the magnetic field suitable for water injection and the state of the magnetic field suitable for pumping by controlling the direction of the current to the coiled conductive portion. Sometimes, the effect of the magnetic field treatment can be enhanced by strengthening the magnetic fields of the two coiled conductive portions.

  According to the third aspect of the invention, since the coiled conductive portion is formed so as not to cross the water permeable hole, it is possible to increase the strength against earth pressure and prevent the hole area ratio from being reduced.

  According to the fourth aspect of the invention, since the screen is formed of a plurality of support rods and a coiled rigid wire, and the conducting wire is attached to the end of the rigid wire on the side opposite to the support rod, It can be easily manufactured without greatly changing the structure of the existing screen with an aperture ratio.

  According to the fifth aspect of the invention, since one end portion in the longitudinal direction is wide and the fitting groove for inserting the lead wire is formed in the intermediate portion in the width direction of the end portion over the entire length of the rigid wire. It is suitable for the well clogging prevention system of 4 means.

1 is an overall view of a well clogging prevention system according to a first embodiment of the present invention. FIG. 2 is a cutaway perspective view of the system of FIG. 1 with the inner screen highlighted. FIG. 3 is a partially enlarged view of the screen of FIG. 2. It is principal part sectional drawing of the screen of FIG. It is action explanatory drawing at the time of water injection of the system of FIG. It is action explanatory drawing at the time of pumping of the system of FIG. It is a principal part longitudinal cross-sectional view of the screen of FIG. It is sectional drawing of the rigid wire of FIG. It is a figure which shows the analysis result of the effect | action for the time of water injection of the system of FIG. It is a figure which shows the analysis result of the effect | action for the time of pumping of the system of FIG. It is a figure which shows the manufacturing process of the screen of FIG. It is explanatory drawing of the manufacturing process of FIG. It is an expanded sectional view of the important section of the system of a 2nd embodiment of the present invention. It is sectional drawing of the rigid wire of the modification of the system of FIG. It is an expanded sectional view of the screen of the system of a 3rd embodiment of the present invention. It is sectional drawing which shows the modification of the system of FIG. It is a front view which shows the modification of the screen of the system of this invention. It is a front view which shows the other modification of the screen of the system of this invention. It is a general view of the reference example of this invention. It is explanatory drawing of the effect | action at the time of the water injection of the example. It is explanatory drawing of the effect | action at the time of pumping of the example.

  1 to 12 show a well clogging prevention system according to a first embodiment of the present invention or a rigid wire to be applied to this system.

For the convenience of explanation, the well-known matters will be explained first in the configuration of the well to which the present invention is applied. FIG. 1 schematically illustrates the structure of a well. The well 2 includes a bottom wall 4 and a peripheral wall 6 and is inserted into a vertical hole B formed in the ground. The vertical hole B reaches the aquifer L ₂ through the poorly permeable layer L ₁ of the ground. Further, the vertical hole B has a diameter larger than that of the peripheral wall 6 of the well as shown in FIG. 5, and a filter material (gravel) F is provided in a portion corresponding to the aquifer in the gap between the outer surface of the peripheral wall and the vertical hole. The soil S is backfilled in the portions corresponding to. However, the drawing of the filter material is omitted in the drawing. As shown in FIG. 1, the upper part of the peripheral wall 6 is a casing 8 that does not allow water to pass through, while the lower part of the peripheral wall 6 is a water-permeable screen 10. The screen 10 is formed by integrally combining a plurality of support rods 12 that are loop-shaped when viewed from above and a rigid wire 14 that is spirally wound around the support rods. As shown in FIG. 7, the upper end portion 12 b of the support rod 12 is fixed to the lower portion of the inner surface of the casing 8, and the lower end portion 12 a of the support rod 12 is fixed to the bottom portion 4. The bottom portion 4 in the illustrated example has a cylindrical portion 4b upright from the outer periphery of the bottom wall 4a, and a lower end portion of a support rod is attached to the inner surface of the cylindrical portion 4b.

  The rigid wire 14 has sufficient rigidity to resist at least earth pressure. As known in the art, this rigid wire can be a wedge-shaped wire that is long in the direction perpendicular to the support rod 12 (in the radial direction of the well) as shown in FIGS. The wedge-shaped rigid wire 14 has a sharp first end 16 and a wide second end 18, and the first end 16 is welded to each support rod 12.

The well in the illustrated example is provided with a pumping pipe 24A and a water injection pipe 24B so that both a pumping process and a water injection (recharge) process are possible. When the clogging prevention system according to the present invention is not operated, the clogging-causing substance M in the running water adheres to the hole edge of the water permeable hole 22 of the screen and generates a scale. Moreover, the two adjacent wire portions of the coiled wire and the two support rods 12 adjacent to each other form a water permeable hole 22. The vertical width D of the water permeable hole 22 is determined so that soil or filter material backfilled around the screen 10 does not enter the well. The filter materials generally used vary widely from 1 mm to 13 mm and vary depending on the ground, application, and area. In order to prevent the filter material from entering the inside of the well, assuming that the particle diameter of 85% of the passing mass percentage in the particle diameter accumulation curve is D ₈₅ and the coil interval (the width of the permeation hole) is D. D ₈₅ / D> 2 and may be.

  In this invention, as shown in FIG. 5, the lower part of the surrounding wall 6 of a well is made into the double surrounding wall, and these are made into the inner screen 10A and the outer screen 10B. The gap between the inner screen 10A and the outer screen 10B is filled with the filter material F. The well clogging prevention system 30 of the present invention includes the inner screen 10 </ b> A and the outer screen 10 </ b> B, and further includes a coiled conductive portion 32, power supply lines 38 </ b> A, 38 </ b> B, 39 </ b> A, and 39 </ b> B, and a power supply portion 40. First, the configuration of the inner screen 10A will be described.

  The coiled conductive portion 32 is attached to the wide second end 18 of the rigid wire 14 over the entire length of the rigid wire. By providing a conductive portion along the spiral rigid wire 14, a coiled conductive portion is obtained. As shown in FIG. 8, the coiled conductive portion is formed by a conductive wire 34 and an insulation 36 that covers the periphery of the conductive wire. Although the shape of the insulation is arbitrary, the insulation in the illustrated example is flat in the width direction of the second end portion 18. It is desirable that the insulation 36 does not protrude from the width of the second end 18. By energizing the coiled conductive portion 32, a magnetic field is generated, and this magnetic field suppresses deposition of scale-causing substances in running water on the surface of the object. The reason for this phenomenon is not fully understood, but is generally interpreted as follows. First, by flowing water charged by the action of a magnetic field, particles such as ions are not deposited on the surface of the object (the particles in this state are referred to as inactive particles). Secondly, the thus generated inert particles collide with the scale material already formed on the object and drop off from the surface of the object.

  Next, the outer screen 10B is connected to the bottom 4 and the casing 8 by appropriate connecting means so as to surround the inner screen 10A. As a preferred example, as shown in FIG. 4, the bottom portion 4 stands up from the outer periphery of the bottom wall 4 a via the outward flange 46. Moreover, the casing 8 protrudes from the lower part of the outer peripheral surface of the flange-like connecting plate 50 to which the base end portion is fixed, and suspends the second connecting cylinder 52 from the tip of these connecting plates. The first connecting cylinder 48 and the second connecting cylinder 52 may be formed to have the same inner diameter, and both end portions 12a and 12b of the support rod 12 of the outer screen 10B may be fixed to the inner surfaces of both the cylinders. In the illustrated example, the inner screen 10A and the outer screen 10B are wound in the same direction. However, since the current can be flown in either direction, the winding direction is not necessarily the same. In the drawing, the pitch length is the same, but the pitch length is not necessarily the same because the particle size of the filter material and the particle size of the soil particles are different. As a preferred embodiment, the pitch length of the inner screen 10A is so fine that the filter material does not enter the well, and the pitch length of the outer screen 10B is set large enough to allow the filter material to enter between both screens. can do.

  Both ends of the coiled conductive part of the inner screen 10A are connected to the power supply part 40 by power supply lines 38A and 39A, and both ends of the coiled conductive part of the outer screen 10B are connected to the power supply part 40 by power supply lines 38B and 39B, respectively. Each feeder line is a covered electric wire.

  The power feeding unit 40 is connected in parallel to the two coil-shaped conductive units 32 and can supply current respectively. Of course, any connection may be used as long as an appropriate magnetic field can be applied during water injection and / or pumping. With the above configuration, current can be supplied to one or both of the two coil-shaped conductive portions, and the direction of the current to each coil-shaped conductive portion can also be reversed in the forward and reverse directions. As a preferred embodiment, the cases where the directions of the magnetic fields of the two coil-shaped conductive parts are the same and opposite in the central axis of the well are shown in the drawings, but current is passed through only one of the coil-shaped conductive parts. May also be made possible.

  In the above configuration, first, how the scale precipitates when no magnetic field is applied will be described. In the water injection process, the water injected from the water injection pipe 24 </ b> B is once filled into the well 2. When the water pressure of the injected water in the well becomes greater than the pressure of the underground water at the screen location of the well, the injected water in the well gradually passes through the inner screen 10A and further flows out to the surroundings of the well via the outer screen. To do. In the pumping stroke, when the pumping pump 26 is operated, groundwater is sucked into the well through the outer screen 10B and the inner screen 10A. A scale is a place where scale-causing substances are likely to gather, and is easily generated in a place where the flow is stagnant. Since the inside of the water-permeable hole 12 in the illustrated example is wider in the vertical direction than the outside, the downstream portion immediately after the water-permeable hole tends to be a stagnation place. In particular, the inner screen is placed in a state in which it tends to cause scale because the amount of the scale-causing substance that passes per unit length in the circumferential direction within a unit time is larger than that of the outer screen.

  Next, the operation when a magnetic field is applied will be described. To simplify the description, the operation when a current is passed through one coil-shaped conductive portion 32 will be described first. When a current is passed through the inner coiled conductive portion 32, a strong magnetic field is generated inside the well 2. If water is poured in this state, the scale-causing particles in the injected water that have entered the magnetic field application region from the water injection pipe become inactive due to the action of the magnetic field and pass through without attaching the screen. Alternatively, it is assumed that some particles have an action of colliding with scale particles on the screen surface to remove scale. In the pumping stroke, a current is passed through the outer coiled conductive portion 32. Then, a magnetic field is applied to the inside of the outer coiled conductive part. And the scale cause particle | grains in the groundwater which flowed into the magnetic field application area | region from the periphery will be in an inactive state, and will pass through an inner screen, without adhering.

  Next, an explanation will be given of the operation when current is simultaneously supplied to two coil-shaped conductive portions.

First, a current flows in the same direction relative to the inner screen 10A and outer screen 10B, the inside of the area A _in the inner screen 10A as shown in FIG. 5, the magnetic flux lines inside the coil-like conductive portion and an outer coiled conductor A magnetic field is generated by the sum of the magnetic flux lines of the part. In the present invention, since the coiled conductive portion is designed to include the gap V as a water passage, it is difficult to increase the number of conductors. Instead, the effect of scale prevention due to the generation of a magnetic field in the water injection process is enhanced by making the coiled conductive portion double. That is, this action is advantageous for magnetic treatment of running water during water injection. In the middle of the area A _m of the inner screen 10A and outer screen 10B in this state, it does not work only a weak magnetic field as compared with the inner area A _in.

Then when an electric current is applied to the different orientation relative to the inner screen 10A and outer screen 10B, the intermediate region A _m of the inner screen 10A and outer screen 10B as shown in FIG. 6, the coil-shaped conductive portion of the interior in the region A magnetic field is generated by applying the magnetic flux lines to the magnetic flux lines of the outer coiled conductive portion. Compared with the configurations of FIGS. 19 to 21 of the present application, this action of applying a magnetic field to the intermediate region is advantageous in magnetically treating the flowing water during pumping.

  9 and 10 show the results of the analysis of the magnetic field in the double screen performed by the applicant. FIG. 9 shows the magnitude and direction of the magnetic lines of force when the directions of the magnetic fields generated by the two coiled conductive parts 32 are the same, and FIG. 10 shows the direction of the magnetic field generated by the two coiled conductive parts 32. The magnitude and direction of the lines of magnetic force in the opposite case are indicated by arrows, respectively. The double screen used as the analysis model has an inner screen diameter of 400 mm, an outer screen diameter of 600 mm, and a vertical length of each screen of 6000 mm.

  When the current is supplied to both screens in the same direction, the magnetic field in the inner screen is about 0.34 to 0.49 mT, and the magnetic field in the gap between the inner screen and the outer screen is the magnetic field in the inner screen. It is about half. Further, the magnetic field in the gap between the inner screen and the outer screen when current is supplied to the two screens in different directions is about 0.18 to 0.25 mT. The magnetic field in the inner screen is weaker than the magnetic field in this gap.

  FIG.11 and FIG.12 has shown the process of manufacturing the screen 10 of this embodiment. In this process, the rigid wire 14 is welded to the support rods 12 arranged in a cylindrical shape by seam welding. Seam welding is a method (resistance welding) in which a large amount of current is passed through a welding location while applying resistance heat and pressure (resistance welding). As shown in FIG. Welding is performed continuously across the crossing point of the wire and the covered wire). FIG. 11 shows a screen manufacturing apparatus. This apparatus includes a supporting means for bundling a plurality of support rods in a cylindrical shape, a means for supplying a rigid wire 14, a roller for guiding the rigid wire to a welding location, and a pair of roller electrodes R (provided that the welding location is provided). One electrode is in the blind spot. And the support rod bundled in the cylinder shape is advanced while rotating, and the rigid wire 14 is welded. The rigid wire 14 in the illustrated example is assumed to have a coil-shaped conductive portion assembled in advance as shown in FIG.

  Hereinafter, a system according to another embodiment of the present invention will be described. In the description of these embodiments, the description of the same configuration as that of the first embodiment is omitted.

  13 and 14 show a second embodiment of the present invention. In this embodiment, a fitting groove 20 is formed over the entire length of the rigid wire at the horizontal end of the horizontally long wedge-shaped rigid wire 14, and a coiled conductive portion-forming covered wire is formed in the fitting groove. Fit in. It is preferable to fix the covered electric wire in the fitting groove using an adhesive when fitting. When the rigid wire is attached to the support rod by welding, it is desirable to weld the structure shown in FIG. 14 without the covered electric wire and to fit the covered electric wire after welding. Otherwise, the coating melts with the heat of welding. In the example of illustration, the 2nd end part 18 is made wide, and the fitting groove | channel 20 is drilled in the intermediate part of the longitudinal width direction of the end surface. The width w and the depth h of the fitting groove 20 are formed uniformly over the entire length of the rigid wire as shown in the cross-sectional view of FIG. Otherwise, the operation of fitting the covered electric wire into the fitting groove cannot be performed efficiently. In the illustrated example, the fitting groove 20 is formed in a slightly deep groove (hereinafter referred to as a deep groove) having a depth h equal to or greater than the width w thereof. Furthermore, the cross-sectional shape of the fitting groove 20 in the illustrated example is rectangular. However, any shape (for example, a V shape) may be used as long as the coiled conductive portion 32 can be securely fitted.

One of the reasons for selecting the horizontal end of the horizontally long wedge-shaped rigid wire 14 as the installation location of the fitting groove 20 is to pierce the fitting groove relatively deeply without damaging the strength of the rigid wire. This is because it can be established. For example, when drilling a top S _U lateral width direction intermediate portion fitting groove and the groove of the same degree of depth illustrated in the rigid wire 14 in FIG. 14, the strength of the upper surface of the rigid wire is weakened as compared with the lower surface . As will be described later, when a rigid wire is welded to the outer periphery of the support rod and welded, the rigid wire may be distorted. The reason why the fitting groove is formed at the end opposite to the support rod among the two ends in the horizontal direction is that the end on the support rod side is welded to the support rod, so there is a margin for providing the fitting groove. Because there is no.

  The first function of the fitting groove 20 is to prevent the coiled conductive portion 32 from falling off the rigid wire 14. For this purpose, a fitting groove 20 is formed in the outer end (second end) of the rigid wire wound around the outer periphery of the support rod 12. If the coiled conductive portion 32 is to be dropped out of the fitting groove 20 from this state, the diameter of the coiled conductive portion 32 must be increased by about twice the depth h of the fitting groove. However, even if a part of the coiled conductive portion 32 tries to drop out of the fitting groove 20 due to some external force, the conductive wire 34 of the coiled conductive portion is made of metal and hardly extends to the extent that it is removed from the fitting groove. The coil-shaped conductive portion is fitted in the fitting groove 20 at least for several pitches of the screen, and the action force is applied against the external force applied to a part of the coil by the fitting force in the entire length direction. Thus, the coiled conductive portion 32 is loosened and resists falling off.

  The second function of the fitting groove 20 is to prevent the coiled conductive portion 32 from colliding with another object (such as the inner wall of the pothole). For this purpose, almost all of the coiled conductive portion shown as a longitudinal section in FIG. 14 is fitted in the fitting groove 20.

  The third function of the fitting groove 20 is to keep the thickness of the insulation 36 of the coiled conductive portion 32 in a suitable state. For example, when the coiled conductive portion 32 is attached to the end surface of the second end portion 18 of the rigid wire 6 as in the example of FIG. 8, if the coated conductive wire for forming the conductive portion is pressed and welded, the conductive wire has a flat shape. Is compressed. Then, the insulation 36 is thinned in the compressed direction (horizontal direction when incorporated into the screen). On the other hand, when a coiled conductive part forming conductor is fitted in the fitting groove, almost no force acts on the conductor during welding. Therefore, the insulation 36 does not become thin.

  15 and 16 show a third embodiment of the present invention. For the sake of drawing, the outer screen is omitted and only the inner screen is drawn.

  In the present embodiment, the coiled conductive portion 32 is also used as the screen rigid wire 14. That is, as shown in FIG. 15, the rigid wire has a property as a conducting wire, and its periphery is covered with the insulation 36. In the drawing, only the rigid wire / coiled conductive portion of the inner screen is drawn, and the rigid wire / coil conductive portion of the outer screen is omitted. As shown in FIG. 15, the rigid wire 14 is welded to the plurality of support rods 12. However, as shown in FIG. 16, the coiled conductive portion 32 can be fitted into the fitting recess 13 formed outside the series of support rods 12.

  17 and 18 show a fourth embodiment of the present invention. This embodiment shows aspects other than the spiral screen. The screen shown in FIG. 17 is obtained by mounting a plurality of stages of reinforcing rings 42 around a plurality of support rods that are loop-shaped when viewed from above, and winding a coiled conductive portion 32 from the outside of the reinforcing ring. In FIG. 18, a coiled conductive portion 32 is wound around a peripheral wall having a large number of water permeable holes 22. In any of the illustrated examples, only the configuration relating to the inner screen is displayed, and the outer screen is omitted.

  19 to 21 are explanatory diagrams of a reference example of the present invention. In this example, the outer screen is omitted from the configuration of the well clogging prevention system of the present invention. The operation of this example is the same as the inner screen of the system of the first embodiment of the present invention. That is, the clogging cause particles M in the water flow from the water injection pipe 24 </ b> B to the screen 10 in the well are changed to inactive particles M ′ by the action of the magnetic field of the single coiled conductive portion. The inert particles then flow out of the well through the screen.

  However, even in the case of a recharging well, it is necessary to insert a short pumping stroke at a constant rate (for example, 24: 1) during a predetermined time of water injection stroke. This is because if water is allowed to flow only in a certain direction for a long time, foreign substances may block the water channel. The clogging-causing particles around the well are attracted to the screen of the well by the pumping process, and there is a possibility that scale is generated on the screen. In order to prevent this, in the present invention, the screen is doubled.

  Each embodiment described in this specification is a suitable example, and is not limited to this as long as it does not contradict the nature of the invention. For example, only a configuration in which a screen including a coiled conductive portion is doubled is shown as an embodiment. However, from the idea of concentrically overlapping screens to improve magnetic field strength, multiple screens may be used. Absent. In addition, the shape and positional relationship of the rigid wire and the coiled conductive portion can be freely selected as long as the idea of a coil including a gap that is a passage for water is not impaired.

2 ... well 4 ... bottom 6 ... peripheral wall 8 ... casing 10 ... screen
10A ... inner screen 10B ... outer screen 12 ... support rod 13 ... engagement recess
DESCRIPTION OF SYMBOLS 14 ... Rigid wire 16 ... 1st end part 18 ... 2nd end part 20 ... Fitting groove 22 ... Water-permeable hole 24A ... Pumping pipe 24B ... Water injection pipe 26 ... Pumping pump 30 ... Clogging prevention system of a well 32 ... Coil-like conduction Portion 34 ... Conducting wire 36 ... Insulation 38, 39 ... Power feeding line 40 ... Power feeding portion 42 ... Horizontal ring 44 ... Supporting tube 46 ... Outward flange 48 ... First connecting tube 50 ... Connecting plate 52 ... Second connecting tube B ... Vertical hole S ... landfills V ... void P ... upper surface S L _... rigidity of the vertical width w ... Tatehaba h ... fitting groove depth S U _... rigid wire fitting groove pitch length W ... second end of the rigid wire The lower surface of the wire A _in ... inner area A _m ... intermediate area A _out ... outer area

Claims (5)

A system for preventing clogging of a well, which is a screen that allows water to pass through the lower part of a peripheral wall for burying in the ground,
The lower part of the peripheral wall is a double peripheral wall, and each peripheral wall is an inner screen and an outer screen,
Along each peripheral surface of each screen, there is provided a coiled conductive portion extending in a space for passing water between coil portions adjacent to each other in the longitudinal direction of the well, and having an insulating coating on the surface,
Furthermore, a power supply unit that can supply power to each of the coil conductive units is provided.
A well clogging prevention system using magnetic treatment of flowing water.
The power feeding part is designed to energize both the inner coiled conductive part and the outer coiled conductive part and to reverse the direction of the current flowing through at least one of the two coiled conductive parts. It is characterized by
The well clogging prevention system by magnetic treatment of flowing water according to claim 1. The shape and arrangement of the water-permeable holes are designed so that the coiled conductive portion does not cross the water-permeable holes when viewed from the outside of the screen.
The well clogging prevention system by the magnetic treatment of the flowing water of Claim 1 or Claim 2. The screen is composed of a plurality of support rods extending in the longitudinal direction of the well and a coiled rigid wire wound around the outside or inside of the support rods,
While forming each water permeable hole at both the upper and lower edges of the rigid wire and the left and right edges of the support rod,
A conductive wire having an insulated surface is attached as a coil-shaped conductive portion to the end opposite to the support rod among the inner and outer ends of the rigid wire,
The well clogging prevention system by magnetic treatment of flowing water according to claim 3.   A rigid wire suitable for a well clogging prevention system by magnetic treatment of flowing water according to claim 4, having a long cross-sectional shape in one direction, and having one end in the longitudinal direction wide so that the end of the end A rigid wire for a well clogging prevention system, which is formed by drilling a fitting groove for inserting a conductive wire over the entire length of the rigid wire in an intermediate portion in the width direction.

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