JPH1171790A - Strainer screen for deep well - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the quantity of fine sand infiltrated into a strainer, and further decrease the clogging of a filter by winding a plainly-woven fabric on the outer circumference of the strainer in the lower section of a protective pipe at least one time to stick the woven fabric on the outer circumference. SOLUTION: A plainly-woven fabric 30 is wound on the outer circumference of a strainer 22 in the lower section of a protective pipe at one time while containing a matching surface, and stuck by rubber cement, etc. In the woven fabric 30, thickness is set in approximately 2 mm or less, and 15-60 yarn are disposed per length and breadth of 25 mm, and are not twisted, and the fibers of yarn are formed of the glass fiber of continuous fibers. Or they are formed of the synthetic fibers of the continuous fibers. Consequently, a lifting pipe is inserted into the protective pipe up to specified depth. The lifting pipe is connected to a deep well pump, and water is pumped up. Water is flowed into the protective pipe through the strainer 22 from the woven fabric 30, and pumped up onto a ground through the lifting pipe. Accordingly, since the screen of the woven fabric 30 is wound on the stainer 22, the simultaneous lifting of the strainer 22 and the screen is prevented, clogging is not generated, and the efficiency of boring can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deep well strainer screen in which surface water on the ground and spring water from a shallow surface water layer of poor quality are not mixed.

[0002]

2. Description of the Related Art Conventionally, in order to excavate a deep well, Japanese Patent Application No.
As disclosed in US Pat. No. 3,310,025 "Method of drilling a well", a protective tube 2 having a slit 2a at a lower portion is inserted into a well hole 1 shown in FIG. The filter member 3a having a relatively large particle size such as gravel, the seal member 3b having a small particle size such as sand, and the solidified material 3c mixed with cement milk are filled in the upper portion from the bottom. , And pumps water through the pumping pipe 4 through the slit 2a, and the intermediate sealing member 3b is for sealing the permeation of domestic wastewater and cement milk etc. of the solidified material 3c. is there. Therefore, the strainer is
a only, no strainer screen was attached. Since the protective tube 2 is usually made of a hard PVC pipe having an outer diameter of about 60 mm (hereinafter referred to as VP50),
In processing, the size of the slit 2a is limited to 2 to 3 mm. Therefore, the size of the packed gravel, that is, the particle size of the filter member 3a is not the size from the water sampling layer particles, but the size of the slit 2a.
It is determined based on the size of a. Therefore, so-called three-part gravel (about 9 mm below the sieve) or two-part gravel (about 6 mm
Under the sieve), and only relatively coarse ones could be used. That is, the strainer is the slit 2a
Irrespective of whether the sampling layer is a gravel layer or a sand layer, regardless of the size, the filling gravel and the size of the strainer slits 2a had to be all the same, so that the wells where sand came out There were many.

In order to solve the above-mentioned disadvantage, Japanese Patent Application No. 8-12 / 1996
No. 6303 is filed for a method for excavating wells and a filter for a protective tube used therefor (hereinafter referred to as Invention A), and a Japanese Patent Application No. 8-162388 is filed for a "water-blocking packer" (hereinafter referred to as Invention B). Was. In the invention A, as shown in FIG. 10, a well hole 6 having a depth reaching a deep groundwater layer is drilled, and a protection pipe 7 is inserted into this hole. At the lower end of the protective tube 7, a plurality of slits 7a are formed in the outer peripheral surface,
On its outer periphery, a cylindrical shape of a predetermined thickness made of non-woven fabric,
The fibers were piled up in a tongue-and-blade manner, and this nonwoven fabric was provided with a protective tube filter 7b whose inside was dense and gradually coarsened toward the outside. Then, along the outer circumference of the protective tube 7, the seal ring 8 is
It was inserted to a predetermined depth at the inner upper portion, and the space between the inner wall of the hole and the outer periphery of the protective tube 7 was sealed to the ground surface with a cement-based solidifying material 8a. The pumping pipe 9a was inserted into the protection pipe 7, and the upper end thereof was connected to the well pump 9b on the ground.

[0004] Next, as shown in Fig. 11, in the invention B, as shown in Fig. 11, the protection pipe 7 of the invention A has a position immediately below the solidified material 8a of the surface layer A, a position of the intermediate clay layer c, and a position above the lower end strainer 7c. A water-blocking packer 8b was provided to prevent surface water at position A and contaminated water from the gravel layer B above it at position C. E is a pebble layer. At this position, there is a lower end of the protection tube 7, where a strainer 7c around which a filter 7b for the protection tube is wound is installed. The sediment from the ground and the spring water from above were cut off, and the spring water that was not contaminated only by the pebble layer E, which was the lowest layer, was collected.

[0005]

However, in the conventional "well drilling method" shown in FIG. 9, since the strainer is only the slit 2a, as described above, the amount of sand that intrudes into the protection pipe 2 of the well. In addition to the above, when the well pipe 1 is excavated, the protective pipe 2 is inserted into the outer pipe, and when the gravel of the filter member 3a is filled while the outer pipe is being pulled out, the gravel fills a gap between the outer pipe and the protective pipe 2. When the outer tube was pulled out and the outer tube was pulled out, there was a case where the protective tube 2 was in an up state and the protective tube 2 could not be installed.

In the case of using a cylindrical sponge-shaped protection tube filter 7b made of non-woven fabric for the strainer 7c as in the inventions A and B, fine sand hardly permeates into the protection tube 7. However, as shown in FIG. 12, gravel-like pebbles 8c having a large particle size are fitted between the outer fibers 7d,
There was a drawback of clogging.

Further, in the case where gravel is used as the filter member 3a shown in FIG.
In the case of the invention B, since the protective tube filter 7b has a cylindrical shape and a large thickness, the inner diameter of the outer tube is 3 to more than the outer diameter of the protective tube 2, 7 when the respective well holes 1 and 6 are excavated. I had to make it bigger than 4 inches.

[0008] The present invention has been made in view of the above-described circumstances, and the amount of fine sand entering the strainer is small.
In addition to providing a clogging of a filter wound around a strainer, a diameter of an outer tube for drilling a well hole can be reduced, and a strainer screen for a deep well without a protection tube rising during construction. It is.

[0009]

According to the present invention, there is provided a strainer screen for a deep well according to the present invention, wherein a plain woven cloth is provided at least once on the outer periphery of the lower strainer in a protective tube used for a deep well. Wound and pasted.

[0010] The woven fabric has a thickness of about 2 mm or less and is formed of continuous fiber glass fiber.
0 lines are provided.

[0011] The woven fabric has a thickness of about 2 mm or less, and is made of continuous synthetic fiber.
0 lines are provided.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. As shown in FIG. 1, the deep well strainer screen of the present invention includes a plain woven fabric 30 around the outer periphery of the strainer below the protective tube 21 (FIG. 8) including a seam (or two or more times). It is rolled and pasted with rubber glue. However, the woven fabric 30 is the strainer 2
2 may be glued only to the joint where the upper and lower ends of the strainer 22 and the woven fabric 30 partially overlap. The opening of the strainer 22 has a hole of 20 mm in diameter.
mm, the woven fabric 30 is not drawn in even in the case of a hole or a slit.
It is sufficient that the strength of No. 2 is maintained. FIG. 1 is a diagram in which a woven fabric 30 is wound around a strainer 22, and shows a case where a slit 22a is provided. The strainer 22 is located in the aquifer d shown in FIG. As shown in FIG.
The effect of 0 is that the yarn 3 of the woven fabric 30
1 is flat, and the particles of sand 41 (particle diameter: about 1 to 2 mm) are in contact with the outside of the yarn 31, so that the particles do not get caught in the eyes of the yarn 31, and thus no clogging occurs. The spring water passes between the fibers 31a of the yarn 31.

The structure of the woven fabric 30 has a thickness of about 2 mm.
The thread 31 is 15 to 60 per 25 mm in length and width.
The fiber 31a of the yarn 31 is preferably a continuous fiber (filament) glass fiber, and a fiber generally called a glass fiber cloth is preferable, but the fiber 31a is a synthetic fiber such as nylon. It may be made of

As shown in FIG. 8, the space between the well hole 60 and the strainer screen is filled with sand 41 as a buried material. The protection tube 21 has an outer diameter of 60 in this embodiment.
A VP 50 of mm is used, and a sand trap 23 having the same material (or another material) and a cylindrical lower end closed as shown in FIGS. At the lower part, two pairs of anchors 50, 50 projecting obliquely upward from the outer periphery and having the same outer diameter as the outer tube 11 project. The structure penetrates through the sand trap 23 as shown in FIGS.
A pair of claws 51, 51 projecting outward and obliquely upward are bent. As a material of the anchor 50,
A 0.2-0.5 mm thick stainless steel plate is preferred. The function of the anchor 50 is to remove the outer tube 11 while removing the sand 4 as described later.
This is to prevent the protection tube 21 from going up together when 1 is input, but may not be necessary depending on the case. Further, the sand trap 23 may not be provided only by extending the lower portion of the strainer 22.

Next, a deep well excavation process using the deep well strainer screen of the present invention will be described. First, a well hole having a predetermined depth is drilled in the ground with a double pipe. The predetermined depth is up to the lower impermeable layer indicated by e in FIG. In this case, it is efficient to use a rotary percussion drill. Next, as shown in FIG. 4, the inner pipe 12 is pulled up to the ground. In the figure, reference numeral 11 denotes an outer tube. Next, FIG. 5, FIG.
As shown in (2), the protective tube 21 is inserted into the outer tube 11 to the bottom of the hole.

Next, as shown in FIG. 7, while pulling out the outer tube 11, from the ground between the outer tube 11 and the protective tube 21, as indicated by an arrow f, sand as a burying material having a particle size of about 1 to 2 mm. 41 is input.

Next, as shown in FIG. 8, the well hole 60 and the protective tube 21 are extended to the depth of the upper impermeable layer c below the surface water layer b.
During this time, a cement grout material is introduced from the ground surface and solidified to form a seal grout 61. In this case, as shown in FIGS. 3A and 3B and FIG. 8, four grout hoses 71 to 74 are extended from the upper end of the protective tube 21 to predetermined positions having different depths and are provided on the outer periphery. It is pasted. The open positions of the lower ends of the grout hoses 71 to 74 are distributed and arranged at a depth up to the upper water-impermeable layer c, and even if a hole wall of a certain depth collapses during construction of the seal grout 61,
A cement grout material is injected from a grout hose 70 having a lower end opened above and below, and a seal grout 61 is formed.
Can be formed. The grout hose 70 may be a vinyl-based commercial product. The grouting hose 70 is not required on the ground where there is no risk of collapse of the hole wall, but the provision of the grouting hose 70 can ensure the work.

Next, a pumping pipe (not shown) is inserted into the protection pipe 21 to a predetermined depth. A deep well pump (not shown) installed on the ground is connected to the pumping pipe.

The pumping will be described with reference to FIG. Since the seal grout 61 is constructed up to the upper impervious layer b, the sewage flowing on the ground surface, the sewage that has permeated the topsoil layer a, and the sewage flowing out from the surface water layer b are separated by the seal grout 61 and the upper impervious layer c. Will be shut off. Then, the spring water of the uncontaminated aquifer d passes through the sand 41 of the buried material, flows into the protective tube 21 via the woven fabric 30 → the strainer 22, and
It is pumped to the ground by a deep well pump via a water pump. A small amount of fine sand passing through the nonwoven fabric 30 accumulates in the sand trap 23.

[0020]

According to the present invention described in detail above,
The following effects are obtained. (1) Since the conventional protective tube has a structure in which only a strainer is provided with a slit, the gravel, which is a filter member between the well hole and the strainer, is filled. In many cases, the protective tube inserted between the rising outer tube and the gravel became wedge-shaped and could not be installed, making it impossible to construct.However, in the present invention, since the woven fabric screen is wound around the strainer, , Rising is prevented.

(2) In the present invention, since the woven fabric is wound at least once around the outer periphery of the strainer, it does not become clogged as in the case of the conventional filter for a protective tube made of a sponge-like nonwoven fabric.

(3) Since the strainer screen of the present invention is made of a woven fabric, it is thinner than a conventional sponge-shaped nonwoven fabric protective tube filter, so that the inner diameter of the outer tube to be drilled is 10 times smaller than the outer diameter of the protective tube. The drilling efficiency is improved because it is only required to be about 20 mm larger.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a strainer screen of the present invention, in which (a) shows a longitudinal section and (b) shows a side face excluding a part of a woven fabric.

FIG. 2 is an explanatory view of a use state of a woven fabric of the strainer screen of the present invention.

3A and 3B are explanatory views of another part of the protective tube provided with the strainer screen of the present invention, wherein FIG. 3A shows the arrangement of a grout hose and an anchor, and FIG. 3B shows the grout hose attached to the protective tube. (C) shows a cross section in which the anchor is attached to the sand trap.

FIG. 4 is an explanatory view showing a construction process of a deep well using the strainer screen of the present invention.

FIG. 5 is an explanatory view showing a construction process of a deep well using the strainer screen of the present invention.

FIG. 6 is an explanatory view showing a construction process of a deep well using the strainer screen of the present invention.

FIG. 7 is an explanatory view showing a construction process of a deep well using the strainer screen of the present invention.

FIG. 8 is a sectional view of a deep well using the strainer screen of the present invention.

FIG. 9 is a diagram showing a cross section of a deep well using a conventional strainer.

FIG. 10 is a cross-sectional view of a deep well in a state in which a filter for a guard tube in the form of a spatula is attached to a conventional strainer.

FIG. 11 is a cross-sectional view of a deep well in a case where a filter for a protection tube in the form of a toe is attached to a conventional strainer, and a water-blocking packer is used in the middle of the protection tube.

FIG. 12 is an explanatory diagram of a usage state of a filter for a protection tube used in a conventional deep well.

[Explanation of symbols]

 21 Protection Tube 22 Strainer 30 Woven Fabric 31 Yarn 31a Fiber

Claims (3)

[Claims] In a protective tube used for a deep well, at least one plain woven fabric is provided on the outer periphery of a lower strainer.
A strainer screen for deep wells, which is wound and attached. 2. The woven fabric has a thickness of about 2 mm or less, and 15 to 60 yarns, which are made of continuous fiber glass fibers and are not twisted or slightly twisted, per 25 mm in length and width. The strainer screen for deep wells according to claim 1, wherein the strainer screen is formed. 3. The woven fabric has a thickness of about 2 mm or less, and 15 to 60 yarns of 25 mm in length and width which are made of synthetic fibers of continuous fibers and are not twisted or slightly twisted are provided. The strainer screen for deep wells according to claim 1, wherein the strainer screen is formed.