KR20060123685A - Design of fluid extraction well made with porous media with multiple porosity for the remediation of contaminated underground - Google Patents

Abstract

A wall body structure for fluid injection well comprising a porous media with multiple pores as a wall body capable of increasing area of contact with soil and preventing efficiency reduction caused by closing of the pores is provided to efficiently suck a fluid such as underground water or gas within soil or smoothly inject chemicals for decomposing contaminants into the soil. In a wall body structure for a fluid extraction well and a fluid injection well used in a process of in-situ remediation of a contaminated underground space, a method for manufacturing the fluid extraction well comprises the steps of: (a) preparing cylindrical porous media with different pore sizes as materials for wall bodies; (b) preparing a porous media with large pore size as an outer wall body(21) of the fluid extraction well; (c) preparing a porous media with small pore size as an inner wall body(23) of the fluid extraction well; and (d) constructing the fluid extraction well by closing top and bottom covers(25,26) on top and bottom of the wall body; and (e) installing the fluid extraction well at a contaminated soil area.

Description

Design of Fluid Extraction Well Made with Porous Media with Multiple Porosity for the Remediation of Contaminated Underground}

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.

1 is a cross-sectional view showing a side of a fluid extraction well with a screen composed of several slits in the prior art.

2 is a cross-sectional view of a fluid extraction well having a porous medium having various pore sizes as a wall;

3 is a-a 'cross-sectional view of the fluid extraction well of FIG.

4 is a cross-sectional view showing the velocity of the contaminants in the fluid extraction direction and the velocity in the fluid extraction direction and in the vertical direction in a porous medium of varying pore size having three different pore sizes;

5 is a field application example of a fluid extraction well having a multi-porous porous medium as a wall.

<Explanation of symbols for the main parts of the drawings>

11: Prior Art Fluid Extraction Wall 12: Slit

21: wall with large porous cylindrical porous media 22: wall with medium porous cylindrical porous media 23: wall with small porous cylindrical porous media 24: fluid extraction path 25: upper lid 26: lower lid 27: fluid Extraction pipe 41: Velocity of fluid movement in the fluid extraction direction in a porous medium having large sized voids 42: Velocity of fluid flow in the fluid extraction direction and vertical direction in a porous medium having large sized voids 43: Movement speed of the fluid in the fluid extraction direction in the porous medium having 44. Movement speed of the fluid in the fluid extraction direction and the vertical direction in the porous medium having the medium size voids. 45: Direction of fluid extraction in the porous medium having the small size voids. 46: velocity of fluid movement in the fluid extraction direction and in the vertical direction in a porous medium with small sized voids Figure 56: contaminated soil 57: bentonite seal 58: pump 59: bedrock

Soil pollution cases such as landfills, gas stations, military units, etc. are frequently reported, and a lot of technical efforts are put into smooth disposal. Technical classification of oil pollution soil restoration method is divided into Ex Situ method that excavates and treats contaminated soil and In Situ method that treats in situ without excavation. Soil Vapor Extraction and Pump and Treat are typical methods for in situ methods, and the common embodiment of these two methods involves the use of pipe-type fluid extraction wells at various points within the contaminated site. By inserting forcibly contaminated groundwater or contaminated gas to reduce the concentration of pollution.

The conventional technology of such a fluid extraction well is a screen consisting of a plurality of slits in three directions of the wall in the bottom of the extraction well and inserts a pipe-type fluid extraction well by drilling the soil to a specific depth as specified in Republic of Korea Patent Registration 10-0462118 1 shows a screen of such a fluid extraction well. However, since the suction area affecting the fluid suction efficiency is limited to the entire area of the slit, efficient suction of the fluid is difficult. In addition, since the size of the slit, which is the passage of the fluid, is constant, soil particles smaller than the size of the slit flow into the suction well and flow into the pump, which causes a failure of the pump installed on the ground, and the slit is blocked by the soil particles. In many cases, the efficiency of fluid extraction decreases rapidly.

Another form of in-situ treatment involves the injection of agents that can oxidize soil contaminants into the ground through fluid injection wells. Conventional Utility Model No. 20-0308522, which is a prior art of fluid injection wells, is designed to inject a liquid material in a wide direction by forming a constant array of injection nozzles at the bottom and the circumferential part of the injection well so that the liquid material is finely dispersed using high pressure in the ground. . However, these nozzles are very likely to break during insertion into the ground, and the nozzles are very likely to be clogged by small particles of soil.

The present invention is a component applied to the in situ contaminated soil purification device, more specifically, a fluid injection that can smoothly inject a fluid, such as groundwater and gas in the soil or drugs that can decompose contaminants into the soil. Related to the structure of the wall, it is characterized by using a multi-porous porous medium as a wall, which has a large contact area with the soil capable of inhaling or injecting fluid, and prevents the decrease in efficiency due to the blockage of the pores.

The present invention is to solve the problem that the screen consisting of a plurality of slits of the prior art fluid extraction well is occluded with soil particles to reduce the suction efficiency drastically to ultimately increase the efficiency of soil recovery. . Thus, the configuration of the present invention will be described in detail.

The wall of the fluid extraction tablet according to claim 1 of the present invention comprises the steps of preparing a cylindrical porous medium 21 having a relatively large pore, as shown in FIG. 3, and a cylindrical porous medium having a smaller pore size inward. It consists of preparing 22 or 23.

The porous media material does not react with the contaminants contained in the fluid to be sucked, and is also selected to have a certain strength, and preferably a polypropylene porous media may be used to achieve the object of the present invention.

The idea of the present invention can be achieved when the number of porous media layers with different voids is two or more and the operation thereof is explained in more detail. The movement of materials in the porous media with voids is largely due to the action of advection and diffusion. It is well known that large voids in a porous medium have a high velocity of fluid in the voids and dominate movement by advection, and a small velocity of voids causes a slow diffusion of fluid in the voids.

Inhalation of fluids, such as groundwater or gases, through the porous medium can occlude pores in the porous medium by fine soil or sediment. The fluid extraction well having the porous medium having multiple pores as a wall according to claim 1 is a porous medium having a large void of the outer wall, which prevents large particles of soil particles from entering the fluid extraction well and provides a velocity of fluid in the void. If a portion of the porous medium of the small voids of the inner wall is occluded because of its fastness, it serves to quickly flow the fluid to the unoccluded portion. The porous medium having a small pore inside the fluid extraction well serves to prevent the fine soil from entering the fluid extraction passage 24 and thus prevents the fine soil from entering the well pump.

The flow of fluid in the porous medium having multiple pores will be described in more detail using a porous medium having three layers of different pores as shown in FIG. 4. In the wall 21 composed of the porous medium having the largest voids, both the flow of the fluid 41 toward the interior of the fluid suction well and the flow 42 in its vertical direction are large. In the porous medium 22 having medium voids, the velocity of the fluid flow is smaller (43 and 44), and in the inner wall (23) having the smallest void size, the velocity of the fluid flow (45 and 46). ) Becomes the smallest.

Therefore, the porous media constituting the wall of the suction well can achieve the effect if two or more voids are different, but preferably, the more layers there can achieve the effect according to the present invention, and the voids gradually increase toward the inside. Small cylindrical porous media can also be used to achieve the spirit of the present invention.

As described in claim 2, a cylindrical porous medium having multiple pores is blocked by the upper lid 25 and the lower lid 26 to constitute a fluid extraction well. When the fluid extraction pipe 27 is connected to the upper lid, the fluid entering the fluid extraction well 24 through the multi-porous porous wall flows out through the fluid extraction pipe 27.

As described in claim 3, the fluid extraction wells can be used for injecting medicaments into the soil as well as for the purpose of fluid intake, as well as another important form of in situ processing.

5 is an embodiment of the present invention. In order to restore the contaminated soil and ground water (56), if the steam extraction method or the chemical injection method is selected as the restoration method by investigating the general situation of the target area, the wells are drilled to the depth required for the contaminated soil. At this time, the depth of the base rock cancer (59) as a rule, but the depth of definition required to efficiently deal with contaminants will vary depending on the site situation. As a next step, a suction well according to the invention is prepared. Prepare a porous medium with an inner diameter of about 5 cm and an outer diameter of about 15 cm, but its length is about 50 cm shorter than the positive depth. The upper and lower lids are connected to the wall to form a fluid extraction well. The next step is to insert the fluid extraction well into the well. Bentonite sealing 57 is constructed to eliminate the space between the fluid fluid extraction well and the contaminated soil. Finally, the step of connecting the fluid extraction pipe 27 and the pump 58 installed on the upper lid of the fluid extraction well is constructed.

In the fluid suction well of the present invention, the suction area of the fluid suction well in contact with the soil is much larger than that of the prior art fluid suction well, so that the removal efficiency of contaminants through the fluid suction is high, and the fine soil is difficult to enter into the fluid suction well. Due to the characteristics of the medium having voids, it is possible to prevent a phenomenon in which the fluid intake due to the blockage of the medium is reduced.

Claims (1)

In the wall structure of the fluid suction well and the fluid injection well used in the process of restoring the contaminated underground space, (a) preparing a porous medium having a large pore size as an outer wall of the fluid extraction well; (b) preparing a fluid extraction well comprising preparing a porous medium having a small pore size as an inner wall of the fluid extraction well.

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