JP2015168981A - Water intake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water intake device capable of pumping underground water of a deep part in a small diameter by a large pumping quantity.SOLUTION: A water intake device comprises a casing pipe 1, a water intake pipe 2 arranged so as to form an annular flow passage 12 of a pressurized fluid in the casing pipe 1 and an ejector mechanism 30 for taking out water flowed in the casing pipe 1 via the water intake pipe 2, and the ejector mechanism 30 comprises a diffuser part 13 formed in a tip part of the water intake pipe 2, an annular thick part 14 formed on the inner periphery of the casing pipe 1 and fixing the diffuser part 13 to a rear end part and a nozzle pipe 15 fixed to the tip part inner periphery of the annular thick part 14 and opening a tip injection hole 15c toward the diffuser part 13 at an interval to the diffuser part 13, and the annular thick part 14 is formed with an inflow hole 22 for making the water flow in the annular thick part by penetrating in the radial direction through this, and is formed with a communication hole 23 for communicating the annular flow passage 12 and the nozzle pipe 15 by penetrating in the axial direction through the annular thick part.

Description

  The present invention relates to a water intake device, and more particularly, to a water intake device that can be simple equipment with a small diameter and that can pump up water such as groundwater at a high head.

  Gravity drainage method represented by Kamaba drainage and deep well as well as well point and vacuum deep well as groundwater level lowering method to be carried out when rooting for structures and tunnel construction etc. The forced drainage method is known. Of these methods, well points are mainly applied when the aquifer is shallow, and deep wells and vacuum deep wells are applied when the aquifer is deep (6 m or deeper). Kamaba drainage is applied when groundwater is not abundant and the depth of root cutting is relatively shallow.

  However, since the well point method is a method of draining groundwater by applying a vacuum to the water collection pipe, the suction depth of the groundwater is limited depending on the degree of vacuum, and complicated maintenance management of the vacuum system is required. There is a difficulty. The deep well construction method is a construction method in which a drainage pump is installed in the well to drain the groundwater, so that the installation well has a large diameter and the pumping system becomes large. Also, the impact on the surrounding area due to pumping is not negligible. Furthermore, since it is a gravity type, the groundwater level cannot be lowered unless the water permeability coefficient of the target aquifer is large.

  The vacuum deep well method was developed to clear this problem of hydraulic conductivity, and is a method of forcibly draining groundwater by applying a vacuum to the strainer tube. However, in this construction method, drainage is not possible unless the well is evacuated and groundwater is collected up to the suction port of the drainage pump. In addition, since the degree of vacuum is applied to the strainer tube, the equipment becomes large. The Kamaba drainage method is a method in which groundwater that penetrates into the excavation part is collected in a pottery located slightly deeper than the bottom of the excavation and drained with a drainage pump. In the case of an aquifer having a large hydraulic conductivity, there is a problem that if the hydraulic conductivity of the ground is not reduced in advance, piping may be caused.

  A pumping device using a jet pump has been proposed as a mechanism for pumping up groundwater. For example, Patent Document 1 discloses a water pumping device in which an inner tube having a venturi portion and an air tube are provided in an outer tube, and a tip portion of the air tube is opened upward at a throat portion of the venturi portion. . However, since this pumping device has a structure in which the inner pipe and the air pipe are inserted into the outer pipe independently, the outer pipe diameter, that is, the well diameter must be increased in order to obtain a required pumping amount. Moreover, since the thing of the literature description is a structure which inserts the front-end | tip part of an air pipe | tube in an inner pipe, the effective cross-sectional area of an inner pipe cannot be taken large, and a pumping amount cannot be enlarged.

  Under the background as described above, the present applicant provides an ejector mechanism, more specifically, a venturi section (ejector body) having a discharge passage penetrating in the radial direction and ejecting jet fluid from the discharge passage into the venturi section. (See Patent Document 2). However, although this apparatus has a small diameter as a whole, the pressurized fluid is injected laterally from the small-diameter discharge flow path, so that the amount of pressurized fluid fed cannot be increased and a large pumping amount is obtained. There was a limit.

JP 2008-57201 A JP 2013-11089 A

The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide a water intake device capable of pumping deep underground water or the like with a small diameter and a large pumping amount.

The present invention employs the following means in order to achieve the above object.
That is, the present invention includes a casing tube having a closed tip,
A water intake pipe disposed in the casing pipe so that an annular flow path of a pressurized fluid is formed between the casing pipe and the casing pipe;
An ejector mechanism for taking out the water flowing into the casing pipe to the outside through the water intake pipe,
The ejector mechanism is
A diffuser portion formed at the tip of the intake pipe;
An annular thick part formed on the inner periphery of the casing tube, the diffuser part being fixed to the rear end part,
Fixed to the inner periphery of the tip of the annular thick portion, and provided with a nozzle tube in which a tip injection hole opens toward the diffuser with a space from the diffuser,
A plurality of inflow holes for allowing water to flow into the annular thick part are formed in the annular thick part at intervals in the circumferential direction. A water intake device characterized in that a plurality of communication holes for communicating the annular flow path and the nozzle pipe through the annular thick wall portion in the axial direction are formed at intervals in the circumferential direction. .

The water intake device is installed as a pumping device in a well formed by excavating the ground,
The filter material filled between the outer periphery of the casing pipe and the hole wall of the well hole can employ a configuration made of a water permeable mat having a three-dimensional solid network structure wound around the outer periphery of the casing pipe. .

  In this case, the water-permeable mat can employ a configuration having a two-layer structure of an inner layer having a small internal porosity and an outer layer having a large internal porosity.

Moreover, this invention is a water intake device installed as a pumping device in a well hole formed by excavating the ground,
An outer casing tube provided with a screen portion in the middle;
An inner casing tube disposed in the outer casing tube and closed at the lower end;
A water intake pipe disposed in the inner casing pipe so that an annular flow path of a pressurized fluid is formed between the inner casing pipe and the inner casing pipe;
An ejector mechanism that pumps groundwater flowing into the inner casing pipe through the screen portion through the intake pipe,
The ejector mechanism is
A diffuser portion formed at a lower end portion of the intake pipe;
An annular thick part formed on the inner periphery of the casing tube, the diffuser part being fixed to the upper end part,
Fixed to the inner periphery of the lower end of the annular thick portion, and provided with a nozzle tube in which a tip injection hole opens toward the diffuser portion at a distance from the diffuser portion;
A plurality of inflow holes are formed in the annular thick part at intervals in the circumferential direction through the annular thick part in a radial direction to allow groundwater to flow into the annular thick part. A water intake device characterized in that a plurality of communication holes for communicating the annular flow path and the nozzle pipe through the annular thick wall portion in the axial direction are formed at intervals in the circumferential direction. .

  In the above water intake device, the filter material filled between the outer periphery of the outer casing tube and the hole wall of the well hole is made of a water permeable mat having a three-dimensional three-dimensional mesh structure wound around the outer periphery of the outer casing tube. A configuration can be employed.

  In this case, the water-permeable mat can employ a configuration having a two-layer structure of an inner layer having a small internal porosity and an outer layer having a large internal porosity.

Further, in each of the water intake devices, at least one intermediate amplification mechanism is provided in the water intake pipe above the ejector mechanism,
This intermediate amplification mechanism
A nozzle pipe disposed in the intake pipe and having a tip injection hole opening upward;
While supporting this nozzle pipe, the structure provided with the said annular flow path and the some support pipe which connects a nozzle pipe is employable.

  In this case, a configuration in which a diffuser portion is formed in the intake pipe above the nozzle pipe can be adopted.

  According to the present invention, it is possible to pump a large amount of groundwater or the like having a small diameter and a deep portion.

It is 1st Embodiment which applied the water intake device by this invention as a pumping device, Comprising: It is sectional drawing which shows the whole structure. The detail of the ejector mechanism provided in the lower part of a pumping-up apparatus is shown, (a) is an axial direction sectional view, (b) is an AA arrow directional cross-sectional view of (a). It is a figure which shows the relationship between arrangement | positioning of a some pumping apparatus, and piping installed on the ground. It is 2nd Embodiment which applied the water intake apparatus by this invention as a pumping apparatus, Comprising: It is sectional drawing which shows the whole structure. It is 3rd Embodiment which applied the water intake device by this invention as a pumping device, Comprising: It is sectional drawing which shows the whole structure. The detail of an intermediate | middle amplification mechanism is shown, (a) is an axial direction sectional drawing, (b) is a BB arrow directional cross-sectional view of (a).

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the overall configuration of a first embodiment in which a water intake device according to the present invention is applied as a pumping device. The pumping device includes a double pipe having a casing pipe 1 and a water intake pipe 2 arranged in the casing pipe 1. In this embodiment, groundwater is the target of pumping, and as an example of the ground to be pumped, a ground having an aquifer 4 below the surface layer 3 and further having an impermeable layer 5 below is shown.

  The ground is excavated to a depth reaching the impermeable layer 5 to form a well hole 6. The casing pipe 1 is installed in the well hole 6. Between the hole wall of the well hole 6 and the casing tube 1, the filter material 7 is filled in a portion deeper than this including the aquifer 4 portion, and the water shielding material 8 made of clay or the like is further buried above the filter material 7. A sealing material 9 made of a return material (sand, generated soil), mortar or the like is provided. The present invention is also characterized with respect to the filter material 7, which will be described later. The upper end of the casing tube 1 is closed by a flange 10. The intake pipe 2 is connected to a collecting pipe 25 (see FIG. 3) via a connecting pipe 11 provided on the flange 10.

  An ejector mechanism 30 is provided at the lower part of the pumping device, and FIG. 2 shows the details thereof. 2A is a sectional view in the axial direction, and FIG. 2B is a sectional view taken along line AA in FIG. The lower end of the casing tube 1 is closed. An annular channel 12 for supplying pressurized fluid is formed between the casing pipe 1 and the intake pipe 2. An ejector mechanism 30 that generates a venturi effect by supplying a pressurized fluid includes a diffuser portion 13 provided at a lower end portion of the intake pipe 2, an annular thick portion 14 formed on an inner periphery of the casing tube 1, And a nozzle tube 15.

  In this embodiment, the diffuser portion 13 is formed as a separate member from the intake pipe 2, and the upper end portion is fixed to the lower end portion of the intake pipe 2 with a screw 16. The lower end portion of the diffuser portion 13 is fixed to the inner periphery of the upper end portion of the annular thick portion 14 with a screw 17. At the lower end portion of the diffuser portion 13, a stepped portion 18 for positioning that engages with the upper end of the annular thick portion 14 is formed.

  The nozzle tube 15 has a main body 15 a and a tapered portion 15 b, and the tapered portion 15 b is fixed to the inner periphery of the lower end portion of the annular thick portion 14 with a screw 16. The tip injection hole 15c of the taper portion 15b opens upward toward the diffuser portion 13 with a distance from the lower inlet of the diffuser portion 13. Between the main body 15a of the nozzle tube 15 and the tapered portion 15b, a stepped portion 19 for positioning that engages with the lower end of the annular thick portion 14 is formed.

  In this embodiment, the annular thick portion 14 is formed as a separate member from the casing tube 1, and upper and lower ends thereof are fixed to the casing tube 1 by screws 20 and 21, respectively. The annular thick portion 14 is provided with a plurality of groundwater inflow holes 22 that penetrate the radial thick portion 14 in the radial direction. The tip injection hole 15 c of the nozzle tube 15 opens at substantially the same height level as the inflow hole 22. The annular thick portion 14 is formed with a plurality of communication holes 23 penetrating in the axial direction at intervals in the circumferential direction. The annular flow path 12 and the nozzle tube 15 communicate with each other through these communication holes 23. The step portion 18 of the diffuser portion 13 and the step portion 19 of the nozzle 15 have outer diameter dimensions that do not close the communication hole 23.

  Referring again to FIG. 1, the filter material 7 filled between the casing tube 1 and the hole wall of the well hole 6 is made of a water permeable mat having a three-dimensional solid network structure. As the water-permeable mat, for example, “Hetimaron” (trade name, Shinko Nylon Co., Ltd.) can be used. The filter material 7, that is, the water permeable mat, is wound around the casing tube 7 in advance before the casing tube 1 is installed in the well hole 6. The filter material 7 includes two layers, an inner layer 7a and an outer layer 7b. A water-permeable mat having a small internal porosity is used for the inner layer 7a, and a water-permeable mat having a large internal porosity is used for the outer layer 7b. In this embodiment, a water-permeable mat having the same internal porosity as that of the outer layer 7b is also disposed as the bottom layer 7c of the filter material at the bottom of the well hole 6.

  As the filter material 7, granular materials such as cinnabar sand may be used as in the conventional case, but the following advantages are obtained by using the water-permeable mat having the above three-dimensional three-dimensional network structure. . Since the space between the casing pipe 1 and the hole wall of the well hole 6 is filled with the filter material 7 attached to the outer periphery of the casing pipe 1 in advance, the filling time does not occur and the filling time is shortened. Can do. Moreover, since the filter material 7 consists of two layers, the inner layer 7a and the outer layer 7b, which have different internal void ratios, the groundwater can be filtered step by step. Further, since the outer layer 7b has a large internal porosity, the groundwater easily penetrates into the outer layer 7b, and therefore, the floating due to the resistance of the groundwater can be suppressed when the casing pipe 1 is installed.

  As shown in FIG. 3, a plurality of pumping wells equipped with the pumping device as described above are installed according to the scale of the construction site where the groundwater level is lowered. The intake pipe 2 of each pumping device is connected to a collecting pipe 25 installed on the ground via a connecting pipe 11. A pressurized fluid supply pipe 26 is also installed on the ground. For example, compressed air or pressurized water can be used as the pressurized fluid, and the pressurized fluid supply pipe 26 is connected to a compressor or a pressurized pump. The annular flow path 12 of each device is connected to the pressurized fluid supply pipe 26 via a connecting pipe 27.

  Next, the operation of the pumping device will be described with reference to FIG. As described above, a pressurized fluid such as compressed air or pressurized water is supplied to the annular flow path 12. The pressurized fluid flows into the bottom portion of the casing tube 1 through the communication hole 23 of the annular thick portion 14, and enters the nozzle tube 15 as an upward flow at the bottom portion of the casing tube 1. Further, the pressurized fluid is injected toward the diffuser portion 13 from the tip injection hole 15 c of the nozzle tube 15. The injected pressurized fluid increases in flow velocity in the vicinity of the tip injection hole 15c of the nozzle tube 15 to become a jet flow, and the speed head occupies almost all of the total pressure, so that the pressure decreases accordingly.

  Due to this pressure drop, the groundwater that has entered the well hole 6 is sucked into the annular thick part 14 through the filter material 7 and the inflow hole 22 and is instantaneously mixed with the pressurized fluid in the diffuser part 13. Thereafter, the pressurized fluid accompanying the groundwater is diffused toward the outlet of the diffuser section 13 where the flow path expands, and the jet flow converges and is converted back to pressure (Venturi effect). In this way, groundwater is introduced into the intake pipe 2 and pumped up. In FIG. 2, the flow of pressurized fluid is indicated by solid arrows, and the flow of groundwater is indicated by broken arrows.

  According to the pumping device as described above, the pumping device is composed of the casing pipe 1, the water intake pipe 2, and the ejector mechanism 30, so that the pumping well can be reduced in diameter, and the forced drainage construction method in a narrow area is applied. become able to. Further, since the pressurized fluid supplied to the annular flow path 12 between the casing pipe 1 and the intake pipe 2 is jetted from the nozzle pipe 15 provided below the diffuser section 13, Since the effective cross-sectional area can be widened and the amount of pressurized fluid fed can be increased, the pumping amount can be increased.

  FIG. 4 is a sectional view showing the overall configuration of a second embodiment in which the water intake device according to the present invention is applied as a pumping device. In the second embodiment, the casing pipe 1 shown in the first embodiment is used as an inner casing pipe, and an outer casing pipe 31 is provided outside the casing pipe 1 so as to form a triple pipe as a whole. Upper ends of the outer casing pipe 31 and the inner casing pipe 1 are closed by a flange 10. A screen portion 32 for allowing groundwater to flow in is provided at the intermediate portion of the outer casing pipe 31. The screen portion 32 is formed by a known winding, for example, and is provided at a position corresponding to the aquifer 4.

  Between the outer casing pipe 31 and the well hole 6, a filter material 7 made of the same water-permeable mat as shown in the first embodiment and having an inner layer 7 a and an outer layer 7 b is provided. This filter material 7 is also wound around the outer periphery of the outer casing tube 31 before the outer casing tube 31 is installed in the well hole 6. Other configurations including the ejector mechanism 30 are the same as those in the first embodiment.

  In the case of this second embodiment, the inflow of groundwater into the outer casing pipe 31 can be promoted by setting the annular gap 33 between the inner casing pipe 1 and the outer casing pipe 31 to a negative pressure. The groundwater flowing into the outer casing pipe 31 through the filter material 7 is introduced into the water intake pipe 2 and pumped up by the action of the ejector mechanism 30 as described in the first embodiment.

  In the case of the first embodiment, the casing pipe 1 and the intake pipe 2 cannot be pulled out from the ground during the construction period of the groundwater level lowering method after the casing pipe 1 is installed in the well hole 6. In the case of the embodiment, since the inner casing pipe 1 and the water intake pipe 2 can be pulled out even during the construction period, maintenance of the ejector mechanism 30 and the like can be performed.

  5 and 6 show a third embodiment in which the water intake device according to the present invention is applied as a pumping device. FIG. 5 is a cross-sectional view showing the entire structure of the pumping device, FIG. 6 shows details of the intermediate amplification mechanism, (a) is a cross-sectional view in the axial direction, and (b) is a cross-sectional view taken along line BB in (a). is there. In the third embodiment, an intermediate amplifying mechanism 35 is provided in the pumping pipe 2 above the ejector mechanism 30.

  As shown in FIG. 6, the intermediate amplifying mechanism 35 includes a nozzle pipe 36 and a plurality of support pipes 37 for supporting the nozzle pipe 36 on the water pipe 2. The nozzle tube 36 has a main body 36a and a tapered portion 36b fixed to the upper portion of the main body 36a, and a tip injection hole 36c of the tapered portion 36b opens upward. The support tube 37 is formed of a fully threaded tube having a screw formed on the outer periphery, and one end is fixed to the water intake tube 2 and the other end is fixed to the main body 36 a of the nozzle tube 36. Thereby, the annular flow path 12 and the nozzle pipe 36 communicate with each other. The intake pipe 2 is provided with a diffuser portion 38 above the nozzle pipe 36 at a distance.

  The pressurized fluid supplied to the annular flow path 12 enters the nozzle pipe 36 through the support pipe 37 and is jetted toward the diffuser portion 38 from the tip injection hole 36c. The flow rate of the injected pressurized fluid increases near the tip injection hole 36c of the nozzle tube 36, and the pressure decreases accordingly. Due to this pressure drop, the rise of groundwater in the intake pipe 2 is promoted. Note that when compressed air is used as the pressurized fluid, an air lift action can be expected, and the diffuser portion 38 is not necessarily provided.

  The number of intermediate amplification mechanisms 35 is not limited to one, and a plurality of intermediate amplification mechanisms 35 may be installed at intervals in the axial direction so as to be multistage. Moreover, this intermediate | middle amplification mechanism 35 is applicable not only to the pumping apparatus shown in 1st Embodiment but the pumping apparatus shown in 2nd Embodiment. In addition, when showing the size of each pipe used in the pumping device, for example, the intake pipe 2 is 32A, the (inner side) casing pipe 1 is 50A, and the outer casing pipe is 80A, which is of a very small diameter.

The above embodiment is merely an example, and the present invention can take various aspects. In the above embodiment, the case where the water intake device according to the present invention is applied as a pumping device and the groundwater is pumped up in the vertical direction has been described, but the water intake device according to the present invention is installed horizontally in the natural ground, and the groundwater in the natural ground is It can also be applied to horizontal water intake. That is, the water intake device according to the present invention can be installed in any angular direction.
In addition, the water to be taken in is not limited to groundwater. For example, contaminated water collected in the bulk of a bulk carrier, contaminated water collected in a recess such as ore in the cargo hold, and also from a landfill site Any water can be targeted, such as the generated leachate.

1 Casing tube (inner casing tube)
2 intake pipe 3 surface layer 4 aquifer 5 impermeable layer 6 well hole 7 filter material 12 annular flow path 13 diffuser part 15 nozzle pipe 30 ejector mechanism 31 outer casing pipe 32 screen part 35 nozzle pipe 35 intermediate amplification mechanism 36 nozzle pipe

Claims (8)

A casing tube with a closed tip;
A water intake pipe disposed in the casing pipe so that an annular flow path of a pressurized fluid is formed between the casing pipe and the casing pipe;
An ejector mechanism for taking out the water flowing into the casing pipe to the outside through the water intake pipe,
The ejector mechanism is
A diffuser portion formed at the tip of the intake pipe;
An annular thick part formed on the inner periphery of the casing tube, the diffuser part being fixed to the rear end part,
Fixed to the inner periphery of the tip of the annular thick portion, and provided with a nozzle tube in which a tip injection hole opens toward the diffuser with a space from the diffuser,
A plurality of inflow holes for allowing water to flow into the annular thick part are formed in the annular thick part at intervals in the circumferential direction. A water intake device, wherein a plurality of communication holes for communicating the annular flow path and the nozzle tube through the annular thick portion in the axial direction are formed at intervals in the circumferential direction. The water intake device is installed as a pumping device in a well formed by excavating the ground,
The filter material filled between the outer periphery of the casing tube and the hole wall of the well hole is formed of a water permeable mat having a three-dimensional three-dimensional network structure wound around the outer periphery of the casing tube. 1. The water intake device according to 1.   3. The water intake device according to claim 2, wherein the water permeable mat has a two-layer structure of an inner layer having a small internal porosity and an outer layer having a large internal porosity. A water intake device installed as a pumping device in a well hole formed by excavating the ground,
An outer casing tube provided with a screen portion in the middle;
An inner casing tube disposed in the outer casing tube and closed at the lower end;
A water intake pipe disposed in the inner casing pipe so that an annular flow path of a pressurized fluid is formed between the inner casing pipe and the inner casing pipe;
An ejector mechanism that pumps groundwater flowing into the inner casing pipe through the screen portion through the intake pipe,
The ejector mechanism is
A diffuser portion formed at a lower end portion of the intake pipe;
An annular thick part formed on the inner periphery of the casing tube, the diffuser part being fixed to the upper end part,
Fixed to the inner periphery of the lower end of the annular thick portion, and provided with a nozzle tube in which a tip injection hole opens toward the diffuser portion at a distance from the diffuser portion;
A plurality of inflow holes are formed in the annular thick part at intervals in the circumferential direction through the annular thick part in a radial direction to allow groundwater to flow into the annular thick part. A water intake device, wherein a plurality of communication holes for communicating the annular flow path and the nozzle tube through the annular thick portion in the axial direction are formed at intervals in the circumferential direction.   The filter material filled between the outer periphery of the outer casing tube and the hole wall of the well hole is formed of a water permeable mat having a three-dimensional three-dimensional mesh structure wound around the outer periphery of the outer casing tube. The water intake device according to claim 4.   6. The water intake device according to claim 5, wherein the water permeable mat has a two-layer structure of an inner layer having a small internal porosity and an outer layer having a large internal porosity. At least one intermediate amplifying mechanism is provided in the intake pipe above the ejector mechanism;
This intermediate amplification mechanism
A nozzle pipe disposed in the intake pipe and having a tip injection hole opening upward;
The water intake device according to any one of claims 1 to 6, further comprising a plurality of support pipes that support the nozzle pipe and communicate the annular flow path with the nozzle pipe.   The water intake device according to claim 7, wherein a diffuser portion is formed in the water intake pipe above the nozzle pipe.

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