Drainage system for saline-alkali soil and installation method

Abstract

The invention relates to a drainage system for saline-alkali soil and an installation method, the drainage system for saline-alkali soil comprises an inspection well which is vertically arranged and is at least partially buried underground, the inspection well is internally provided with a containing cavity with a top opening, and the side wall of the inspection well is provided with a through hole; the concealed pipe is transversely arranged underground, the first end of the concealed pipe is arranged in the through hole in a penetrating mode, the first end of the concealed pipe is provided with a water outlet communicated with the containing cavity, the second end of the concealed pipe is closed, and water inlet holes are formed in the surface of the concealed pipe; the drainage mechanism comprises a drainage pump and a drainage pipe used for draining water in the containing cavity, the drainage pump and at least part of the drainage pipe are arranged in the containing cavity, and the drainage pump is communicated with the drainage pipe; the floating body is arranged in the containing cavity, connected with the drainage pump and configured to float upwards to control the drainage pump to work when the liquid level rises to the position of the water outlet. Sewage in the inspection well is prevented from flowing back into the concealed pipe, the whole drainage system does not need to be additionally provided with a water collecting pipe, and the concealed pipe direct drainage mode is adopted, so that the blocking risk of the concealed pipe is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of saline-alkali land drainage, and in particular to a saline-alkali land drainage system and an installation method. Background Art

[0002] At present, the combined system of underground pipes and water collection pipes is mostly used to control the groundwater level in saline-alkali land. The underground pipes are buried below the critical depth in the farmland. When the groundwater level rises to the underground pipes, the water will be discharged into the water collection pipes. The water in the water collection pipes will be collected in the water collection wells or open ditches for unified discharge.

[0003] However, since the underground pipes are buried deep underground, although they are protected by the filter layer, silt can easily enter the underground pipes, and eventually enter the water collection pipes and water collection wells. Once blocked, the drainage and salt removal functions of all underground pipes after the blockage point will fail. Over time, the water collection wells are filled with silt. When blockage occurs, it is mainly dredged manually, which is time-consuming and labor-intensive, and can only temporarily relieve the blockage. Summary of the invention

[0004] Based on this, it is necessary to provide a drainage system for saline-alkali land that does not require a water collection pipe and avoids the risk of blockage of concealed pipes.

[0005] The present application provides a drainage system for saline-alkali land, comprising an inspection well, which is arranged vertically and at least partially buried underground, wherein a cavity with an open top is provided in the inspection well, and a side wall of the inspection well is provided with a perforation; a concealed pipe, which is arranged horizontally underground, wherein a first end of the concealed pipe is penetrated in the perforation, and the first end of the concealed pipe has a water outlet communicated with the cavity, the second end of the concealed pipe is closed, and a water inlet is arranged on the surface of the concealed pipe; a drainage mechanism, comprising a drainage pump and a drainage pipe for discharging water in the cavity, wherein the drainage pump and at least a part of the drainage pipe are arranged in the cavity, and the drainage pump is communicated with the drainage pipe; a float, which is arranged in the cavity, the float is connected to the drainage pump, and is configured so that when the liquid level rises to the water outlet, the float floats upward to control the operation of the drainage pump.

[0006] In one embodiment, a filter screen for sludge to pass through is arranged in the cavity below the water outlet, and the filter screen divides the cavity into a receiving cavity and a filtering cavity which are connected in sequence from top to bottom. The drainage pump is located in the receiving cavity and is placed on the filter screen.

[0007] In one of the embodiments, a support foot for supporting the filter is provided at the bottom of the filter, and the support foot extends downward. When the filter is arranged in the cavity, at least a portion of the bottom surface of the support foot is in contact with the bottom of the cavity.

[0008] In one embodiment, the height of the supporting foot is H, and the height H satisfies: 50cm>H≥10cm, and filter holes are distributed on the filter screen, and the aperture of the filter holes is greater than 1cm.

[0009] In one of the embodiments, when the liquid level rises to the position at the water outlet, the float is located below the water outlet.

[0010] In one embodiment, the upper end of the inspection well extends out of the ground and is located above the ground, the distance between the top of the concealed pipe and the ground is h1, the distance between the bottom of the concealed pipe and the inner bottom end of the inspection well is h2, and the distances h1 and h2 satisfy: h1≥1m, 0.8m>h2≥0.5m.

[0011] In one of the embodiments, the concealed pipe and the inspection well are arranged in sequence along a first direction, the concealed pipe is gradually inclined downward along the first direction, and the longitudinal slope of the concealed pipe is 0.8‰ to 1.2‰.

[0012] In one embodiment, there are at least three water inlet holes, which are arranged at intervals along the circumference of the concealed pipe. The concealed pipe is a corrugated pipe with crests and troughs. The water inlet holes are located at the troughs. The outer peripheral wall of the concealed pipe is covered with a water-permeable and corrosion-resistant protective layer, and the outer periphery of the protective layer is covered with a coarse sand layer.

[0013] In one embodiment, the side wall of the inspection well is provided with an opening at a position above the ground for the drainage pipe to pass through, the ground is recessed downward to form a drainage ditch, the opening is located beside the drainage ditch, the portion of the drainage pipe after passing through the opening is a water outlet section, and the water outlet section is connected to the drainage ditch.

[0014] The present application also discloses a method for installing a drainage system, wherein the drainage system is the drainage system described in any one of the above embodiments, and the installation method comprises the following steps in sequence:

[0015] Step 1), surveying the topography of the saline-alkali land, determining the depth and direction of laying the concealed pipe, and then covering the outer peripheral wall of the concealed pipe with a water-permeable and corrosion-resistant protective layer, and covering the outer periphery of the protective layer with a coarse sand layer;

[0016] Step 2), the inspection well is buried vertically underground, and the first end of the concealed pipe is inserted into a perforation of the side wall of the inspection well;

[0017] Step 3), placing a filter screen arranged transversely at the bottom of the cavity, with a gap between the bottom wall of the filter screen and the bottom wall of the cavity;

[0018] Step 4), placing a drainage pump on the top surface of the filter screen, when the water level in the cavity of the inspection well reaches the height of the blind pipe outlet, the float will control the drainage pump to work, and the drainage pipe will discharge the water in the cavity to the outside.

[0019] Compared with the prior art, in the drainage system provided by the present application, a drainage pump and a float are arranged in the inspection well. The float can float upward under the action of water. When the water level discharged into the inspection well through the concealed pipe outlet reaches the water outlet of the concealed pipe, the float moves upward to start the drainage pump. The drainage pump works to discharge the water in the inspection well through the drainage pipe, thereby preventing the sewage in the inspection well from flowing back into the concealed pipe. The entire drainage system does not require an additional water collection pipe, and adopts a concealed pipe direct discharge method, which reduces the risk of clogging of the concealed pipe, has good salt and water removal effects, and is simple to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 A structural diagram of a drainage system according to an embodiment of the present application;

[0022] Figure 2 for Figure 1 Schematic diagram of the local structure of the central concealed pipe.

[0023] Figure numerals: 1. inspection well; 11. containing cavity; 111. containing cavity; 112. filter cavity; 12. manhole cover; 2. concealed pipe; 20. water outlet; 200. crest; 201. trough; 202. water inlet; 21. protective layer; 22. coarse sand layer; 3. drainage mechanism; 31. drainage pump; 32. drainage pipe; 321. water outlet section; 4. float; 5. filter screen; 51. supporting foot; 6. drainage ditch; 61. first position; 7. ground. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0025] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a centered component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a centered component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right", "side", "top", "bottom" and similar expressions used in the specification of this application are only used to describe the various example structural parts and elements of the present application, but these terms are used here only for the purpose of convenience of explanation, and are determined based on the example orientations shown in the accompanying drawings, and do not represent the only implementation method. Since the embodiments disclosed in the application can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0028] It should be noted that "axial arrangement" means that the overall arrangement direction is along the axial direction, including but not limited to axial extension, and may form an angle with the axial direction.

[0029] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0030] like Figure 1 and Figure 2As shown, the present application discloses a drainage system for saline-alkali land. The drainage system includes an inspection well 1, a concealed pipe 2, a drainage mechanism 3 and a floating body 4. The inspection well 1 is arranged vertically and at least partially buried underground. A cavity 11 with an open top is provided in the inspection well 1, that is, the top of the inspection well 1 is open. The side wall of the inspection well 1 is provided with a perforation.

[0031] like Figure 1 and Figure 2 As shown, the concealed pipe 2 is arranged horizontally underground, the first end of the concealed pipe 2 is inserted into the perforation, and the first end of the concealed pipe 2 has a water outlet 20 connected to the cavity 11, the second end of the concealed pipe 2 is closed, and the surface of the concealed pipe 2 is arranged with a water inlet hole 202. In one embodiment, there are two water inlet holes 202. In this embodiment, there are at least three water inlet holes 202, and they are arranged at intervals along the circumference of the concealed pipe 2.

[0032] In this embodiment, the second end of the concealed tube 2 is tied and blocked with nonwoven fabric, thereby achieving the closure of the second end. In addition, other methods can also be used to achieve closure.

[0033] The drainage mechanism 3 includes a drainage pump 31 and a drainage pipe 32 for draining water from the cavity 11. The drainage pump 31 and at least a portion of the drainage pipe 32 are disposed in the cavity 11, and the drainage pump 31 is connected to the drainage pipe 32. In this embodiment, a portion of the drainage pipe 32 is located in the cavity 11.

[0034] The float 4 is disposed in the chamber 11, is connected to the drainage pump 31, and is configured to float upward to control the operation of the drainage pump 31 when the liquid level rises to the water outlet 20. In other words, the float 4 serves as a component for controlling the start and stop of the drainage pump 31. The working principle of the float 4 driving the drainage pump 31 to start and stop is the same as that in the prior art, and will not be described in detail in this embodiment.

[0035] It can be understood that by arranging the drainage pump 31 and the float 4 in the inspection well 1, the float 4 can float upward under the action of water. When the water level discharged into the inspection well 1 through the outlet 20 of the concealed pipe 2 reaches the outlet 20 of the concealed pipe 2, the float 4 moves upward to start the drainage pump 31. The drainage pump 31 works to discharge the water in the inspection well 1 through the drainage pipe 32, thereby preventing the sewage in the inspection well 1 from flowing back into the concealed pipe 2. The entire drainage system does not need to be additionally provided with a water collection pipe, and adopts a direct discharge method of the concealed pipe 2, which reduces the risk of blockage of the concealed pipe 2, has good salt and water removal effects, and is simple to maintain.

[0036] In this embodiment, when the liquid level rises to the position of the water outlet 20, the float 4 is located below the water outlet 20. In this way, the reliability of the operation of the float 4 can be ensured, and when the water level reaches the water outlet 20, the situation where the float 4 fails to drive the drainage pump 31 to work is avoided.

[0037] The top opening of the inspection well 1 is covered with a well cover 12, which can be opened or closed. Opening the opening facilitates the maintenance or replacement of the drainage pump 31. Closing the opening prevents users from accidentally falling into the well, thereby increasing safety.

[0038] A filter screen 5 for sludge to pass through is arranged in the chamber 11 below the water outlet 20 . The filter screen 5 divides the chamber 11 into a receiving chamber 111 and a filtering chamber 112 which are connected in sequence from top to bottom. The drainage pump 31 is located in the receiving chamber 111 and is placed on the filter screen 5 .

[0039] It can be understood that due to the presence of the filter screen 5, the sludge in the concealed pipe 2 that enters the cavity 11 through the water outlet 20 is deposited in the filter cavity 112 after passing through the filter screen 5. The drain pump 31 is placed on the filter screen 5 to prevent the drain pump 31 from contacting the sludge, thereby reducing the risk of the drain pump 31 being blocked and extending the service life of the drain pump 31.

[0040] In addition, when the sludge in the filter chamber 112 of the inspection well 1 reaches the surface of the filter screen 5, the water in the inspection well 1 is drained, and the filter screen 5 is lifted with a lifting rope for manual dredging. After the dredging is completed, the filter screen 5 is put back to the bottom of the well.

[0041] In order to better support the drainage pump 31 , the filter screen 5 is made of a stainless steel mesh to ensure the strength of the filter screen 5 .

[0042] The bottom of the filter 5 is provided with a support foot 51 for supporting the filter 5, and the support foot 51 extends downward. When the filter 5 is arranged in the cavity 11, at least part of the bottom surface of the support foot 51 is in contact with the bottom of the cavity 11. It can be understood that the existence of the support foot 51 better supports the filter 5. In another embodiment, a support portion for supporting the filter 5 can also be provided on the inner peripheral wall of the inspection well 1. In this embodiment, there are at least two support feet 51.

[0043] The height of the support foot 51 is H, and the height H satisfies: 50cm>H≥10cm. The filter screen 5 is provided with filter holes, and the aperture of the filter holes is greater than 1cm. It can be understood that the height of the support foot 51 is within the above range, which can better protect the drainage pump 31 while ensuring the number of times of cleaning the sludge.

[0044] The upper end of the inspection well 1 extends out of the ground 7 and is located above the ground. The distance between the top of the concealed pipe 2 and the ground 7 is h1, and the distance between the bottom of the concealed pipe 2 and the inner bottom end of the inspection well 1 is h2. The distances h1 and h2 satisfy: h1 ≥ 1m, 0.8m>h2 ≥ 0.5m. The upper limit of the depth h1 of the concealed pipe is affected by the actual groundwater level. The depth of the concealed pipe is selected according to the actual situation, as long as a good drainage and salt removal effect can be achieved. The setting of the above-mentioned distance h2 can ensure that the inspection well is at a reasonable depth while ensuring that the floating body floats reliably, effectively solving the problem of increased costs caused by excessive burial depth.

[0045] The ground 7 is sunken downward to form a drainage ditch 6. The side wall of the inspection well 1 is provided with an opening for the drainage pipe 32 to pass through at a position above the ground 7. The opening is located beside the drainage ditch 6. The portion of the drainage pipe 32 after passing through the opening is a water outlet section 321, which is connected to the drainage ditch 6. It can be seen that the first end of the concealed pipe 2 is arranged close to the drainage ditch 6, while the second end of the concealed pipe 2 is arranged away from the drainage ditch 6.

[0046] In addition, the drainage ditch 6 can be the original drainage ditch 6 of the saline-alkali land, and the inspection well 1 and the concealed pipe 2 are arranged at a position close to the drainage ditch 6.

[0047] In one embodiment, the end of the water outlet section 321 is placed on the periphery of the drain ditch 6. In this embodiment, the distance between the opening and the ground 7 is less than 5 cm. After the drain pipe 32 is installed, cement plugging measures should be taken for the opening to prevent soil from entering the inspection well 1. The orthographic projection of the water outlet section 321 is located in the drain ditch 6. The position where the edge of the top opening of the drain ditch 6 contacts the drain pipe 32 is the first position 61. The distance between the first position 61 and the water outlet section 321 is 10 cm, that is, the length of the water outlet section 321 exceeding the edge of the drain ditch 6 is 10 cm. It can be understood that the water outlet section 321 exceeds the edge of the drain ditch 6, so that the water flowing out of the water outlet section 321 can flow into the drain ditch more reliably, avoiding the discharged water from flowing to the ground.

[0048] The distance between the top of the inspection well 1 and the ground is h3, and the distance h3 satisfies: 30cm≤h3≤40cm. It can be understood that the top of the inspection well is higher than the ground. On the one hand, it prevents water on the ground from seeping into the cavity of the inspection well when it rains; on the other hand, it is convenient to observe the location of the inspection well.

[0049] The concealed pipe 2 and the inspection well 1 are arranged in sequence along the first direction x, the concealed pipe 2 gradually tilts downward along the first direction x, and the longitudinal slope of the concealed pipe 2 is 0.8‰ to 1.2‰. Within the aforementioned longitudinal slope range, the purpose of cost saving can be achieved while ensuring that the water flow in the concealed pipe reliably flows into the inspection well.

[0050] like Figure 2 As shown, there are at least three water inlet holes 202, which are arranged at intervals along the circumference of the concealed pipe 2. The concealed pipe 2 is a corrugated pipe with wave crests 200 and wave troughs 201. The water inlet holes 202 are located at the wave troughs. The outer peripheral wall of the concealed pipe 2 is covered with a water-permeable and corrosion-resistant protective layer 21, and the outer periphery of the protective layer 21 is covered with a coarse sand layer 22. It can be understood that the water inlet holes 202 are arranged at the wave troughs 201, and a certain gap is left between the water inlet holes 202 and the outer protective layer 21, which reduces the risk of the water inlet holes 202 being blocked. In this embodiment, the protective layer 21 is a non-woven fabric.

[0051] The water inlet hole 202 may be oval or long. In addition, there is no obvious burr at the water inlet hole 202. The present application also discloses an installation method of the drainage system, which includes the following steps in sequence:

[0052] Step 1), survey the topography of the saline-alkali land, determine the depth and direction of laying the concealed pipe 2 according to the actual situation, then cover the outer peripheral wall of the concealed pipe 2 with a water-permeable and corrosion-resistant protective layer 21, the outer periphery of the protective layer 21 is covered with a coarse sand layer 22, the thickness of the coarse sand layer 22 is not less than 10 cm, the outer diameter of the concealed pipe 2 is not less than 110 mm, the longitudinal slope of the concealed pipe 2 is between 0.8‰ and 1.2‰, and the second end of the concealed pipe 2 is bundled with a non-woven fabric and the second end of the concealed pipe 2 is blocked;

[0053] Step 2), the inspection well 1 is vertically buried underground, and the first end of the concealed pipe 2 is inserted into the perforation of the side wall of the inspection well 1; wherein the inner diameter of the inspection well 1 is not less than 0.8m, the distance h2 between the bottom of the concealed pipe 2 and the bottom of the well is not less than 0.5m, the height of the inspection well 1 above the ground (i.e., h3) should not be less than 30cm, and the top of the inspection well 1 is covered with a well cover 12;

[0054] Step 3), a filter screen 5 is placed horizontally at the bottom of the cavity 11, and a support leg 51 at the bottom of the filter screen 5 is supported on the bottom of the well, so that a gap is left between the bottom wall of the filter screen 5 and the bottom wall of the cavity 11;

[0055] Step 4), place the drainage pump 31 on the top surface of the filter screen 5. When the water level in the cavity 11 of the inspection well 1 reaches the height of the water outlet 20 of the concealed pipe 2, the float 4 will control the drainage pump 31 to work, and the drainage pipe 32 will discharge the water in the cavity 11 to the outside.

[0056] In this embodiment, the drainage pump 31 is a submersible pump, and the drainage volume should not be less than 1.5m 3 The drainage pipe 32 is a hard pipe made of PE material.

[0057] The installation method of the drainage system is simple. It only needs to bury the concealed pipe 2 and the inspection well 1 underground. There is no need to install a water collecting pipe, that is, there is no need to dig an open ditch required for the water collecting pipe, which reduces the construction cost and reduces the occupation of farmland area due to construction. In addition, the drainage can be completed by relying on the original drainage ditch 6 of the saline-alkali land. The entire drainage system has a simple structure and is convenient for drainage.

[0058] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0059] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A saline-alkali land drainage system, characterized in that: include: An inspection well (1) is arranged vertically and at least partially buried underground, wherein a cavity (11) with an open top is provided in the inspection well (1), and a perforation is provided on a side wall of the inspection well (1); A concealed pipe (2) is arranged horizontally underground, the first end of the concealed pipe (2) is inserted into the perforation, and the first end of the concealed pipe (2) has a water outlet (20) connected to the cavity (11), the second end of the concealed pipe (2) is closed, and a water inlet hole (202) is arranged on the surface of the concealed pipe (2); A drainage mechanism (3) comprising a drainage pump (31) and a drainage pipe (32) for draining water from the cavity (11); the drainage pump (31) and at least a portion of the drainage pipe (32) are arranged in the cavity (11), and the drainage pump (31) is in communication with the drainage pipe (32); A float (4) is disposed in the cavity (11), the float (4) is connected to the drainage pump (31), and is configured such that when the liquid level rises to the water outlet (20), the float (4) floats upward to control the drainage pump (31) to operate.

2. The drainage system according to claim 1, characterized in that: A filter screen (5) for sludge to pass through is arranged in the chamber (11) at a position below the water outlet (20); the filter screen (5) divides the chamber (11) into a receiving chamber (111) and a filtering chamber (112) which are connected in sequence from top to bottom; the drainage pump (31) is located in the receiving chamber (111) and is placed on the filter screen (5).

3. The drainage system according to claim 2, characterized in that: A support foot (51) for supporting the filter (5) is provided at the bottom of the filter (5); the support foot (51) extends downward, and when the filter (5) is arranged in the cavity (11), at least part of the bottom surface of the support foot (51) is in contact with the bottom of the cavity (11).

4. The drainage system according to claim 3, characterized in that: The support foot (51) has a height H, and the height H satisfies: 50cm>H≥10cm. The filter screen (5) is provided with filter holes, and the diameter of the filter holes is greater than 1cm.

5. The drainage system according to claim 1, characterized in that: When the liquid level rises to the position of the water outlet (20), the float (4) is located below the water outlet (20).

6. The drainage system according to claim 1, characterized in that: The upper end of the inspection well (1) extends out of the ground (7) and is located above the ground (7), the distance between the top of the concealed pipe (2) and the ground (7) is h1, and the distance between the bottom of the concealed pipe (2) and the inner bottom end of the inspection well (1) is h2, and the distances h1 and h2 satisfy: h1≥1m, 0.8m>h2≥0.5m.

7. The drainage system according to claim 1, characterized in that: The concealed pipe (2) and the inspection well (1) are arranged in sequence along a first direction, the concealed pipe (2) gradually slopes downward along the first direction, and the longitudinal slope of the concealed pipe (2) is 0.8‰ to 1.2‰.

8. The drainage system according to claim 1, characterized in that: There are at least three water inlet holes (202) arranged at intervals along the circumference of the concealed pipe (2); the concealed pipe (2) is a corrugated pipe having wave crests (200) and wave troughs (201); the water inlet holes (202) are located at the wave troughs (201); the outer peripheral wall of the concealed pipe (2) is covered with a water-permeable and corrosion-resistant protective layer (21); and the outer periphery of the protective layer (21) is covered with a coarse sand layer (22).

9. The drainage system according to any one of claims 1 to 8, characterized in that: The side wall of the inspection well (1) is provided with an opening at a position above the ground (7) for the drainage pipe (32) to pass through, the ground (7) is recessed downward to form a drainage ditch (6), the opening is located beside the drainage ditch (6), the portion of the drainage pipe (32) after passing through the opening is a water outlet section (321), and the water outlet section (321) is connected to the drainage ditch (6).

10. A method for installing a drainage system, characterized in that: The drainage system is the drainage system according to any one of claims 1 to 9, and the installation method comprises the following steps in sequence: Step 1), surveying the topography of the saline-alkali land, determining the depth and direction of laying the concealed pipe (2), and then covering the outer peripheral wall of the concealed pipe (2) with a water-permeable and corrosion-resistant protective layer (21), and covering the outer periphery of the protective layer (21) with a coarse sand layer (22); Step 2), the inspection well (1) is vertically buried underground, and the first end of the concealed pipe (2) is inserted into a hole in the side wall of the inspection well (1); Step 3), placing a laterally arranged filter screen (5) at the bottom of the cavity (11), with a gap between the bottom wall of the filter screen (5) and the bottom wall of the cavity (11); Step 4), place the drainage pump (31) on the top surface of the filter (5), when the water level in the cavity (11) of the inspection well (1) reaches the height of the water outlet (20) of the concealed pipe (2), the float (4) will control the drainage pump (31) to work, and the drainage pipe (32) will discharge the water in the cavity (11) to the outside.

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