Water taking system of water filtering sand pool

Abstract

The invention relates to a water filtering sand pool water taking system which comprises a water taking sand pool, a water taking part and a water conveying part, the water taking sand pool is arranged in an offshore water area, the water taking part is arranged in the water taking sand pool, the water taking part comprises at least one layer of water taking pipe system, and the water taking pipe system comprises a plurality of water-permeable filtering pipelines parallel to one another and a water-impermeable connecting pipeline; a plurality of water permeable holes are uniformly distributed in the side surface of the filtering pipeline, and a nylon wrapping net covers the outer side of the filtering pipeline, so that the water quality filtering effect is improved, and the filtering pipeline is protected; the water conveying part is arranged on land, a water pump and a water conveying pipe of the water conveying part are connected in parallel with a plurality of filtering pipelines through connecting pipelines, and water can be taken from the water taking sand pool; an extra-coarse sand filtering layer, a coarse sand filtering layer and an extra-coarse sand cushion layer are arranged in the water taking and sand pond from top to bottom, and the water taking pipe system is embedded in the coarse sand filtering layer or the extra-coarse sand cushion layer and is used for extracting filtered water.

Description

Technical Field

[0001] The invention belongs to the technical field of water intake engineering, and in particular relates to a water intake system for a water filtering sand pool. Background Art

[0002] Currently, in water intake projects, the main types of water intake heads include box-type, trumpet-shaped, mushroom-shaped, fish-shaped, and inclined plate types. These intake heads are located in deep water areas, far from the shore, and are relatively difficult to construct, resulting in high project costs. In this type of water intake, the water in the water pipeline flows from the sea to the land by gravity, so the bottom of the land-based water intake pool is at a great depth from the land surface. Currently, the rear land area mainly uses a water intake forecourt and pump house to provide water storage and water intake power, or sets up a deep well and uses a vertical deep well pump to draw water. The common disadvantages of these types are the large amount of civil engineering work and the high cost of equipment, making them suitable for large-scale water intake.

[0003] However, the offshore aquaculture industry also has similar water needs. The industry is mainly based on single-household decentralized aquaculture. The above-mentioned water extraction method is too expensive for each farmer who relies on seawater for aquaculture, and the total project cost is difficult for each aquaculture household to accept. Summary of the Invention

[0004] In response to the above problems, the present invention provides a water filtration sand pool water intake system, comprising a water intake sand pool, a water intake unit and a water delivery unit. The water intake sand pool is located in offshore waters, and the water intake unit is located in the water intake sand pool. The water intake unit includes at least one layer of water intake pipe system, and the water intake pipe system includes a plurality of mutually parallel permeable filter pipes and a watertight connecting pipe. A plurality of permeable holes are evenly distributed on the side of the filter pipe, and a nylon net is provided on the outside of the filter pipe to improve the filtering effect and protect the filter pipe.

[0005] The water delivery unit is located on land. The water pump and water delivery pipe of the water delivery unit are connected in parallel with several filter pipes through connecting pipes to draw water from the water sand pool.

[0006] The water intake sand pool is equipped with an extra coarse sand filter layer, a coarse sand filter layer and an extra coarse sand cushion layer from top to bottom. The water intake pipe is buried in the coarse sand filter layer or the extra coarse sand cushion layer to extract the filtered water.

[0007] This invention uses non-gravity water delivery. The depth of the water intake sand pond is significantly smaller than that of traditional deep wells, making it easy to construct and inexpensive, making it suitable for every marine aquaculture household. The water intake sand pond utilizes the tidal patterns of the offshore area to store water, which is then filtered through layers of extra-coarse sand and then coarse sand. The filtered seawater enters a filtration pipeline, then a connecting pipeline, and is then pumped back to land along the water pipe, completing the water intake process. Construction can be carried out during low tide.

[0008] Optionally, the water and sand intake pool is located in the nearshore area of the sea close to the land-sea boundary, within the area affected by the tidal pattern; the water and sand intake pool is in the shape of a cube or an inverted trapezoid, and the depth of the water and sand intake pool is 1 - 1.5 meters below the original sand surface; the bottom and side surfaces of the water and sand intake pool are lined with waterproof membranes.

[0009] Optionally, the extra-coarse sand filter layer, coarse sand filter layer, and extra-coarse sand cushion layer are all horizontal. The extra-coarse sand filter layer and extra-coarse sand cushion layer are filled and laid with extra-coarse sand, and the particle size of the extra-coarse sand is 2 - 4 mm; the coarse sand filter layer is filled and laid with coarse sand, and the particle size of the coarse sand is 0.5 - 1 mm.

[0010] The thickness of the extra-coarse sand cushion layer is 25 - 30 cm, the thickness of the coarse sand filter layer is 35 - 55 cm, and the thickness of the extra-coarse sand filter layer is 35 - 55 cm.

[0011] Optionally, the water intake pipe system is horizontally arranged. The buried depths of the filter pipes and connecting pipes in the same water intake pipe system are the same. The filter pipes are perpendicular to the connecting pipes, and the connecting pipes are connected to the middle of the filter pipes through three-way or four-way pipe fittings; several filter pipes are evenly arranged along the length or width direction of the bottom surface of the water and sand intake pool.

[0012] The side surfaces of the filter pipes are evenly and densely distributed with water permeable holes to facilitate the seawater filtered by the filter layer to enter the filter pipes; the side surface of the connecting pipe is a solid pipe wall and is impermeable to facilitate the transportation of the seawater collected by the filter pipes. The filter pipes and connecting pipes also serve the function of storing water.

[0013] Further optionally, the interval between adjacent filter pipes is 1.2 - 1.8 meters, and the pipe diameters of the filter pipes and connecting pipes are DN250 - DN300.

[0014] Preferably, a set of water intake pipe system is buried at the bottom of the coarse sand filter layer.

[0015] Further optionally, in the case where a set of water intake pipe system cannot meet the water intake requirement, another set of water intake pipe system with the same structure is arranged in the middle and lower part of the extra-coarse sand cushion layer, and the water delivery pipes are connected in parallel to the two sets of water intake pipe systems; the vertical distance between the two sets of water intake pipe systems is 30 - 40 cm, and the filter pipes of the two sets of water intake pipe systems are parallel to each other.

[0016] Optionally, several aeration backwashing pipes are respectively buried inside the extra-coarse sand filter layer and the coarse sand filter layer, which are used to aerate the water and sand intake pool and backwash the two filter layers.

[0017] The aeration backwashing pipe is of a sleeve structure, including an inner aeration pipe and an outer support pipe. The side wall of the support pipe is provided with several through holes. The aeration pipe is a conventional microporous aeration pipe. The support pipe protects the aeration pipe, and the aeration pipe can aerate into the filter layer through the support pipe; a nylon mesh is covered on the outer side surface of the support pipe.

[0018] Further optionally, the main support pipe extends from underground on land to the inside of the water intake sand pond in the sea area, and the main support pipe is connected in parallel to all the support pipes; the main air pipe is connected to the air supply device on land, then extends along the inside of the main support pipe to the inside of the water intake sand pond, and then is connected in parallel to all the aeration pipes to supply air to the aeration pipes.

[0019] Further optionally, a plurality of horizontally arranged first aeration backwashing pipes are provided at the bottom of the extra-coarse sand filter layer, and the first aeration backwashing pipes are all perpendicular to the filter pipes in the coarse sand filter layer. The ratio of the distance between two adjacent first aeration backwashing pipes to the thickness of the extra-coarse sand filter layer is (1.2 - 2):1.

[0020] Further optionally, a plurality of horizontally arranged second aeration backwashing pipes are provided at the bottom of the coarse sand filter layer, and the second aeration backwashing pipes are all parallel to the filter pipes in the coarse sand filter layer. In the coarse sand filter layer, the second aeration backwashing pipes and the filter pipes are at the same depth. The ratio of the distance between two adjacent second aeration backwashing pipes to the thickness of the coarse sand filter layer is (0.8 - 1.4):1.

[0021] Since the coarse sand particle size of the coarse sand filter layer is smaller, the bulk density of this filter layer is greater than that of the extra-coarse sand filter layer. When backwashing the solid dirt accumulated in the coarse sand filter layer, the arrangement density of the second aeration backwashing pipes is larger. Since the filter pipes in the coarse sand filter layer are uniformly arranged, the arrangement density of the second aeration backwashing pipes is also relatively fixed. Therefore, when actually arranging the filter pipes and the second aeration backwashing pipes, the filter pipes and the second aeration backwashing pipes may be relatively close to each other, or a filter pipe may be between two second aeration backwashing pipes. Regardless of the interval size between the filter pipes and the second aeration backwashing pipes, it does not affect backwashing and does not affect water intake. Reasonably select the interval between two adjacent second aeration backwashing pipes to avoid the coincidence of the second aeration backwashing pipes and the filter pipes.

[0022] Optionally, the water conveyance part includes a water pump, a water conveyance pipe, a check valve and a reducing pipe. The middle part of the connecting pipe is connected to the water conveyance pipe through the reducing pipe, and a check valve is provided on the water conveyance pipe. The check valve is between the reducing pipe and the water pump; the water suction port of the water pump is connected to the water conveyance pipe, and the water outlet is connected to the water storage device through a pipe. The water pump pumps the seawater in the water intake pipe system to the water storage device.

[0023] The present invention has the following beneficial effects: A water intake sand pool is set near the shore of the sea area. Utilizing the suction lift of the water pump under standard atmospheric pressure, non-gravity flow water intake is adopted, enabling seawater to flow from a lower place to a higher place. The present invention is set at a certain elevation, and the water pump is higher than the sand well position. Without building traditional water intake forebays, water storage deep wells and using vertical axial flow pumps, a centrifugal pump is directly connected to the water intake pipe system, greatly reducing the excavation and construction workload of the civil engineering on land. The sand excavation in the sea area is shallow, and farmers can carry out construction during the ebb tide, that is, carry out engineering operations during the ebb tide of the tide. On the premise of meeting the water intake requirement of farmers, compared with the construction completely on the sea water, the project cost is greatly saved. The present invention utilizes the tidal law for water intake, taking water when the rising tide covers the water intake sand pool and stopping taking water when the water intake sand pool is exposed during the ebb tide.

[0024] The specific advantages are as follows:

[0025] (1) The excavation depth of the water intake sand pool is shallow, the excavation workload is small, and it is easy to construct; connecting the centrifugal pump to the water intake pipe system does not require underground engineering structures such as land water intake wells and water intake forebays, and the total cost is low;

[0026] (2) The sand source in the water intake sand pool is simple, and the pipes and nylon mesh of the water intake pipe system are common materials, which are easy to purchase;

[0027] (3) The extra-coarse sand filter layer is on the top and the coarse sand filter layer is on the bottom. The pore size of the extra-coarse sand is larger than that of the coarse sand. Impurities with large particles are intercepted by the extra-coarse sand filter layer, and many fine suspended particles will migrate to the coarse sand filter layer, enabling the entire filter layer to play a better role, increasing the penetration depth of impurities, both double-layer filter materials play a good role, and extending the washing cycle of the filter sand;

[0028] (4) The filter pipes and connecting pipes have the functions of water collection and water storage. After water collection, the diameter of the water delivery pipe is reduced. Under the condition of a determined suction lift of the water pump, it is more conducive to water intake;

[0029] (5) The check valve is set close to the water intake sand pool. When the sea ebbs and water intake conditions are not available and the water pump stops sucking water, the check valve will ensure that the water delivery pipe between the check valve and the water pump is filled with water, preventing the seawater in the water delivery pipe from flowing towards the sea side due to gravity, so that the water pump can directly suck water from the sea and supply water to the land next time it starts;

[0030] When the water pump starts to supply water to the land, it will cause a negative pressure in the water delivery pipe. Under the action of atmospheric pressure, the water in the connecting pipe of the water intake sand pool flows into the water delivery pipe behind the check valve, and then water can be continuously taken from the land, and the water pump keeps working; the next time the pump stops, the check valve will still ensure that the water delivery pipe between the check valve and the water pump is filled with water, and then the above-mentioned process is repeated again. Description of the Drawings

[0031] Figure 1Schematic structural diagram of the water intake system of the water filtration sand pool in Embodiment 1;

[0032] Figure 2 Top view schematic diagram of the water intake system;

[0033] Figure 3 Schematic diagram of a part of the filter pipeline;

[0034] Figure 4 Schematic structural diagram of the water intake system of the water filtration sand pool in Embodiment 6.

[0035] In the drawings, 1 - water intake sand pool, 2 - filter pipeline, 3 - connecting pipeline, 4 - permeable hole, 5 - nylon mesh bag, 6 - water pump, 7 - water delivery pipe, 8 - extra-coarse sand filtration layer, 9 - coarse sand filtration layer, 10 - extra-coarse sand cushion layer, 11 - original sand surface, 12 - waterproof film, 13 - first set of water intake pipe systems, 14 - second set of water intake pipe systems, 15 - check valve, 16 - eccentric reducer. Detailed implementation manners

[0036] Embodiment 1

[0037] This embodiment provides a water intake system for a water filtration sand pool. As Figures 1 - 4 shown, it includes a water intake sand pool 1, a water intake part and a water delivery part. The water intake sand pool 1 is located in the offshore waters. The water intake part is arranged in the water intake sand pool 1. The water intake part includes at least one layer of water intake pipe systems. The water intake pipe systems include several mutually parallel permeable filter pipelines 2 and an impermeable connecting pipeline 3. A number of permeable holes 4 are evenly distributed on the side surface of the filter pipeline 2. A nylon mesh bag 5 is sleeved outside the filter pipeline 2 to improve the filtration effect and protect the filter pipeline 2;

[0038] The water delivery part is located on land. The water pump 6 and the water delivery pipe 7 of the water delivery part are connected in parallel with several filter pipelines 2 through the connecting pipeline 3, and can draw water from the water intake sand pool 1;

[0039] An extra-coarse sand filtration layer 8, a coarse sand filtration layer 9 and an extra-coarse sand cushion layer 10 are arranged in the water intake sand pool 1 from top to bottom. The water intake pipe systems are buried in the coarse sand filtration layer 9 or the extra-coarse sand cushion layer 10 to extract the filtered water body.

[0040] The water intake sand pool 1 is located in the near-shore area of the sea close to the land-sea boundary, in the area affected by the tidal law. The water intake sand pool 1 is an inverted trapezoid (that is, the longitudinal section of the water intake sand pool 1 is a trapezoid with a larger upper part and a smaller lower part), and the depth is determined according to the actual water intake needs, generally 1 meter below the original sand surface 11. The depth of the water intake sand pool 1 is much smaller than the depth of more than ten meters or dozens of meters of the water intake deep well;

[0041] The bottom and sides of the water intake sand pool 1 are lined with a waterproof film 12 to prevent seawater from seeping into the bottom or the side walls of the pool body. Seawater seeping in from the bottom or side walls is more likely to carry fine silt in the two filter layers into the filter pipe 2, thus blocking the filter pipe 2 and affecting the water quality of the water intake at the same time. Compared with the seepage water from the bottom and side walls of the pool body, the seawater entering from the top has better quality (according to the principle of gravity, most of the pollutants in the original seawater have settled in the sea area). This seawater then passes through the filter layer from top to bottom, greatly reducing the probability of blocking the filter pipe 2 and extending the service life of the filter layer. The waterproof film 12 can be a conventional waterproof film 12 for engineering or aquaculture. The length of the bottom surface of the water intake sand pool is 18 meters, the width is 16 meters, the height is 1.3 meters, and the inclination angle of the side slope is 45°.

[0042] The extra-coarse sand filter layer 8, the coarse sand filter layer 9, and the extra-coarse sand cushion layer 10 are all horizontal. The extra-coarse sand filter layer 8 and the extra-coarse sand cushion layer 10 are both filled and laid with extra-coarse sand, and the particle size of the extra-coarse sand is 2 - 4 mm; the coarse sand filter layer 9 is filled and laid with coarse sand, and the particle size of the coarse sand is 0.5 - 1 mm.

[0043] The thickness of the extra-coarse sand cushion layer 10 is 30 cm, the thickness of the coarse sand filter layer 9 is 35 cm, the thickness of the extra-coarse sand filter layer 8 is 35 cm, and the top surface of the extra-coarse sand filter layer is flush with the original sand surface.

[0044] The water intake pipe system is horizontally arranged. The buried depths of the filter pipe 2 and the connecting pipe 3 of the same water intake pipe system are the same. The filter pipe 2 is perpendicular to the connecting pipe 3, and the connecting pipe 3 is connected to the middle of the filter pipe 2 through a tee fitting or a cross fitting; eight filter pipes 2 are evenly arranged along the length direction of the bottom surface of the water intake sand pool 1.

[0045] The side of the filter pipe 2 is evenly and densely distributed with water permeable holes 4 to facilitate the seawater filtered by the filter layer to enter the filter pipe 2; the side of the connecting pipe 3 is a solid pipe wall and is impermeable to facilitate the transportation of the seawater collected by the filter pipe 2. The filter pipe 2 and the connecting pipe 3 also serve as a water storage function.

[0046] The interval between adjacent filter pipes 2 is 1.5 meters, and the pipe diameters of the filter pipe 2 and the connecting pipe 3 are DN250. The filter pipe 2 and the connecting pipe 3 are polyethylene PE pipes, which are resistant to seawater corrosion and have a certain strength to resist the stacking weight of the extra-coarse sand and coarse sand and keep the pipes from being flattened.

[0047] The first set of water intake pipe system 13 is buried at the bottom of the coarse sand filter layer 9. The seawater entering from the top of the water intake sand pool 1 passes through the extra-coarse sand filter layer 8 and the coarse sand filter layer 9 in sequence, and then enters the filter pipe 2.

[0048] In the case where a set of water intake pipe systems cannot meet the water intake requirement, a second set of water intake pipe systems 14 with the same structure is further arranged in the middle and lower parts of the extra-coarse sand cushion layer 10 (the lengths of the filter pipes 2 and the connecting pipes 3 are adjusted according to the cross-sectional size of the sand pool where they are located), and the water delivery pipe 7 is connected in parallel with the two sets of water intake pipe systems; the vertical distance between the two sets of water intake pipe systems is 30 cm, and the filter pipes 2 of the two sets of water intake pipe systems are parallel to each other.

[0049] The mesh number of the nylon mesh covering the outside of the filter pipe 2 in the coarse sand filter layer 9 is 30 - 40 meshes, and the mesh number of the nylon mesh covering the outside of the filter pipe 2 in the extra-coarse sand cushion layer 10 is 20 meshes;

[0050] The nylon mesh is flexible, which can protect the outer surface of the filter pipe 2 from being scratched and worn by the extra-coarse sand or coarse sand, and can also play a further filtering role, enabling the seawater to pass through three layers of filtration, namely the extra-coarse sand filter layer 8, the coarse sand filter layer 9, and the nylon mesh, further improving the quality of the taken seawater and preventing blockage in the filter pipe 2 and the connecting pipe 3.

[0051] The water delivery part includes a water pump 6, a water delivery pipe 7, a check valve 15, and an eccentric reducer 16. The middle part of the connecting pipe 3 is connected to the water delivery pipe 7 through the eccentric reducer 16, and a check valve 15 is provided on the water delivery pipe 7, and the check valve 15 is located between the reducer and the water pump 6; the suction port of the water pump 6 is connected to the water delivery pipe 7, and the discharge port is connected to the water storage device through a pipe, and the water pump 6 pumps the seawater in the water intake pipe system to the water storage device.

[0052] The check valve 15 opens towards the water pump 6 side, allowing seawater to flow along the water delivery pipe 7 towards the water pump 6 and preventing the seawater in the water delivery pipe 7 from flowing back; the diameter of the water delivery pipe 7 is DN100 - DN150, the part of the water delivery pipe 7 in the land area is buried underground, and the distance from the ground surface is generally about 100 cm - 120 cm; the water pump 6 is on the ground, and the part of the water delivery pipe 7 close to the water pump 6 passes through the ground and is connected to the water pump 6.

[0053] The water pump 6 is a centrifugal pump, and the height difference between the suction port of the centrifugal pump and the tide level and the total head loss of the water delivery pipe 7 are preferably controlled at 6 - 8 m, and the depth of the water intake sand pool 1 is not deep, which can save energy consumption.

[0054] During the construction of this embodiment, according to the existing technology, sand is dug at low tide in the offshore sea area to form the water intake sand pool 1, then the waterproof film 12 is laid, and then the extra-coarse sand cushion layer 10 and the two filter layers are laid. Among them, the water intake pipe system is laid first, and the connection of each pipe is completed, and then the coarse sand or extra-coarse sand is filled.

[0055] When the water intake quality deteriorates, the extra-coarse sand filter layer and the coarse sand filter layer are flushed with clean water with a certain pressure.

[0056] Embodiment 2

[0057] This embodiment provides a water-filtering sand pool water intake system, which is the same as that of Embodiment 1, except that the thickness of the extra-coarse sand filtering layer is 55 cm.

[0058] Embodiment 3

[0059] This embodiment provides a water-filtering sand pool water intake system, which is the same as that of Embodiment 1, except that the thickness of the extra-coarse sand filtering layer is 34 cm.

[0060] Embodiment 4

[0061] This embodiment provides a water-filtering sand pool water intake system, which is the same as that of Embodiment 1, except that the thickness of the coarse sand filtering layer is 55 cm.

[0062] Embodiment 5

[0063] This embodiment provides a water-filtering sand pool water intake system, which is the same as that of Embodiment 1, except that the thickness of the coarse sand filtering layer is 34 cm.

[0064] Table 1 Comparison of SS of seawater taken in Embodiments 1 - 5

[0065] Item SS (mg / L) Item SS (mg / L) Example 1 15 Example 4 10 Example 2 12 Example 5 21 Example 3 20

[0066] SS is the suspended solid matter in water.

[0067] As can be seen from the above table, the thicknesses of the coarse sand filtering layer and the extra-coarse sand filtering layer need to be reasonably set to achieve good filtering effects. If the thicknesses of the coarse sand filtering layer and the extra-coarse sand filtering layer are too thin, the water quality of the filtered water pipe outlet is poor, which will affect the breeding of marine organisms for farmers; if the thicknesses of the above two filtering layers are too thick, the filtered water volume of the filtered water pipe will decrease, and the economy will deteriorate.

[0068] Embodiment 6

[0069] This embodiment provides a water-filtering sand pool water intake system, which is the same as that of Embodiment 1, except that, as Figure 4 shown, the second set of water intake pipes is not provided, and the water delivery pipe is connected to the middle of the connecting pipe of the first set of water intake pipes. The water intake of this embodiment is less than that of Embodiment 1, but will not drop to half of the water intake of Embodiment 1.

[0070] Embodiment 7

[0071] This embodiment provides a water-filtering sand pool water intake system, which is the same as that of Embodiment 1, except that a number of aeration backwashing pipes are respectively buried inside the extra-coarse sand filtering layer and the coarse sand filtering layer for aerating the water intake sand pool and backwashing the two filtering layers;

[0072] The aeration backwashing pipe is of a sleeve structure, including an inner aeration pipe and an outer support pipe. A number of through holes are provided on the side wall of the support pipe. The aeration pipe is a conventional microporous aeration pipe. The support pipe protects the aeration pipe from being flattened by the filter layer, and the aeration pipe can aerate into the filter layer through the support pipe. A nylon mesh is covered on the outer side of the support pipe to protect the support pipe from being blocked by extra-coarse sand or coarse sand.

[0073] The main support pipe extends from the land underground to the inside of the water intake sand pool in the sea area, and the main support pipe connects all the support pipes in parallel. The main air pipe is connected to the air supply device on land, then extends along the inside of the main support pipe to the water intake sand pool, and then connects all the aeration pipes in parallel to supply air to the aeration pipes. There are no through holes on the side of the main support pipe, and there are no air permeable holes on the surface of the main air pipe. One end of the support pipe far from the main support pipe is closed.

[0074] Both the support pipe and the main support pipe are polyethylene (PE) pipes. The part of the main support pipe buried in the land is about 100 cm - 120 cm from the ground surface. The mesh number of the nylon mesh on the outer side of the support pipe in the extra-coarse sand filter layer is 20 meshes, and the mesh number of the nylon mesh on the outer side of the support pipe in the coarse sand filter layer is 30 - 40 meshes.

[0075] A number of horizontally arranged first aeration backwashing pipes are provided at the bottom of the extra-coarse sand filter layer. The first aeration backwashing pipes are all perpendicular to the filter pipes in the coarse sand filter layer. The ratio of the distance between two adjacent first aeration backwashing pipes to the thickness of the extra-coarse sand filter layer is 1.2:1.

[0076] A number of horizontally arranged second aeration backwashing pipes are provided at the bottom of the coarse sand filter layer. The second aeration backwashing pipes are all parallel to the filter pipes in the coarse sand filter layer. In the coarse sand filter layer, one filter pipe is provided between two adjacent second aeration backwashing pipes. The ratio of the distance between two adjacent second aeration backwashing pipes to the thickness of the coarse sand filter layer is 0.8:1.

[0077] Example 8

[0078] This example provides a water intake system for a filter water sand pool, which is the same as Example 7, except that the ratio of the distance between two adjacent first aeration backwashing pipes to the thickness of the extra-coarse sand filter layer is 2:1.

[0079] Example 9

[0080] This example provides a water intake system for a filter water sand pool, which is the same as Example 7, except that the ratio of the distance between two adjacent first aeration backwashing pipes to the thickness of the extra-coarse sand filter layer is 2.1:1.

[0081] Example 10

[0082] This embodiment provides a water intake system for a water filtering sand pool. It is the same as that of Embodiment 7, except that the ratio of the distance between two adjacent second aeration backwash pipes to the thickness of the coarse sand filter layer is 1.4:1.

[0083] Embodiment 11

[0084] This embodiment provides a water intake system for a water filtering sand pool. It is the same as that of Embodiment 7, except that the ratio of the distance between two adjacent second aeration backwash pipes to the thickness of the coarse sand filter layer is 1.5:1.

[0085] The locations of the following embodiments are in the coastal waters of Xiamen and Zhangzhou. The water intake sand pool is about 200 meters away from the land-sea demarcation line, specifically during the summer aquaculture season.

[0086] Table 2 Cleaning cycles of the two filter layers of the water intake sand pools in Embodiment 1 and Embodiments 7 - 11

[0087]

[0088]

[0089] As can be seen from the above table, compared with the direct cleaning in Embodiment 1, the setting and use of the aeration backwash pipes can greatly improve the cleaning effect of the two filter layers, thereby extending the service life of the filter layers.

Claims

1. A water intake system for a water filtration sand pool, characterized in that, It includes a water and sand intake pool, a water intake part and a water conveyance part. The water and sand intake pool is located in the offshore waters. The water intake part is located in the water and sand intake pool. The water intake part includes at least one layer of water intake pipe systems. Each water intake pipe system includes several mutually parallel permeable filter pipes and an impermeable connecting pipe. A number of permeable holes are evenly distributed on the side surface of the filter pipe, and a nylon net is covered outside the filter pipe. The water conveyance part is located on land. The water pump and water conveyance pipe of the water conveyance part are connected in parallel with several filter pipes through the connecting pipe, and can draw water from the water and sand intake pool. In the water and sand intake pool, there are a very coarse sand filter layer, a coarse sand filter layer and a very coarse sand cushion layer from top to bottom. The water intake pipe system is buried in the coarse sand filter layer or the very coarse sand cushion layer to extract the filtered water body.

2. The water intake system of the water filtration sand pool according to claim 1, characterized in that The water and sand intake pool is located near the shore of the sea area close to the land-sea boundary, in the area affected by the tidal law. The water and sand intake pool is in the shape of a cube or an inverted trapezoid, and the depth of the water and sand intake pool is 1 - 1.5 meters below the original sand surface. The bottom surface and side surfaces of the water and sand intake pool are all laid with waterproof films.

3. The water intake system of the water filtration sand pool according to claim 1, characterized in that, The very coarse sand filter layer, the coarse sand filter layer and the very coarse sand cushion layer are all horizontal. The very coarse sand filter layer and the very coarse sand cushion layer are both filled and laid with very coarse sand, and the particle size of the very coarse sand is 2 - 4 mm. The coarse sand filter layer is filled and laid with coarse sand, and the particle size of the coarse sand is 0.5 - 1 mm.

4. The water intake system of the water filtration sand pool according to claim 3, wherein, The thickness of the very coarse sand cushion layer is 25 - 30 cm, the thickness of the coarse sand filter layer is 35 - 55 cm, and the thickness of the very coarse sand filter layer is 35 - 55 cm.

5. The water intake system of the water filtration sand pool according to claim 1, characterized in that, The water intake pipe system is horizontally arranged. The buried depths of the filter pipes and the connecting pipe in the same water intake pipe system are the same. The filter pipes are perpendicular to the connecting pipe, and the connecting pipe is connected to the middle part of the filter pipe. Several filter pipes are evenly arranged along the length or width direction of the bottom surface of the water and sand intake pool. Permeable holes are evenly and densely distributed on the side surface of the filter pipe, which is convenient for the seawater filtered by the filter layer to enter the filter pipe. The side surface of the connecting pipe is a solid pipe wall, which is impermeable and is used to transport the seawater collected by the filter pipe.

6. The water intake system of the water filtering sand pool according to claim 5, characterized in that, One set of water intake pipe system is buried at the bottom of the coarse sand filter layer, and another set of water intake pipe system with the same structure is buried in the middle and lower part of the very coarse sand cushion layer. The water conveyance pipe is connected in parallel with the two sets of water intake pipe systems, and the filter pipes of the two sets of water intake pipe systems are mutually parallel.

7. The water intake system of the water filtering sand pool according to claim 5, characterized in that Several aeration and backwashing pipes are respectively buried in the very coarse sand filter layer and the coarse sand filter layer, which are used to aerate the water and sand intake pool and backwash the two filter layers. The aeration and backwashing pipe is of a sleeve structure, including an inner aeration pipe and an outer support pipe. A number of through holes are provided on the side wall of the support pipe. The aeration pipe is a microporous aeration pipe. The support pipe protects the aeration pipe, and the aeration pipe can aerate into the interior of the filter layer through the support pipe. A nylon net is covered on the outer side surface of the support pipe. The main support pipe extends from the land underground to the interior of the water and sand intake pool in the sea area. The main support pipe is connected in parallel with all the support pipes. The main air pipe is connected to the air supply device on land, then extends along the interior of the main support pipe to the water and sand intake pool, and then is connected in parallel with all the aeration pipes to supply air to the aeration pipes.

8. The water intake system of the water filtration sand pool according to claim 7, characterized in that, Several horizontally arranged first aeration and backwashing pipes are provided at the bottom of the very coarse sand filter layer. The first aeration and backwashing pipes are all perpendicular to the filter pipes in the coarse sand filter layer. The ratio of the distance between two adjacent first aeration and backwashing pipes to the thickness of the very coarse sand filter layer is (1.2 - 2):

1.

9. The water intake system of the water filtration sand pool according to claim 7, characterized in that, A plurality of horizontally arranged second aeration backwashing pipes are provided at the bottom of the coarse sand filtering layer. The second aeration backwashing pipes are all parallel to the filtering pipes in the coarse sand filtering layer. In the coarse sand filtering layer, the second aeration backwashing pipes and the filtering pipes are at the same depth, and the ratio of the distance between two adjacent second aeration backwashing pipes to the thickness of the coarse sand filtering layer is (0.8 - 1.4):

1.

10. The water intake system of the water filtration sand pool according to claim 1, characterized in that, The water delivery part includes a water pump, a water delivery pipe, a check valve and a reducing pipe. The middle part of the connecting pipe is connected to the water delivery pipe through the reducing pipe. A check valve is provided on the water delivery pipe, and the check valve is between the reducing pipe and the water pump; the water suction port of the water pump is connected to the water delivery pipe, and the water outlet is connected to the water storage device through a pipe. The water pump pumps the seawater in the water intake pipe system to the water storage device.

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