Water treatment device for removing iron and manganese

Abstract

The utility model provides a water treatment device for removing iron and manganese, which relates to the technical field of water treatment devices and comprises a multi-stage manganese sand filter group, a pressurizing and oxygenation aeration pipeline, an ozone input pipeline, a first manganese sand filter group, a second manganese sand filter group, a first valve and a back flushing structure, according to the device, the pressurization and oxygenation aeration pipelines are adopted for aeration type pressurization and oxygenation, ozone is input through the ozone input pipeline, the oxidation effect is further improved, iron and manganese in water can be better oxidized and separated out, the iron and manganese in the water are oxidized and filtered through the two multi-stage manganese sand filtering sets, the oxidation effect is improved, and iron and manganese residues are avoided; the two multi-stage manganese sand filtering groups share the workload, the time interval of back flushing is prolonged, the first manganese sand filtering group and the second manganese sand filtering group can alternately carry out back flushing, it is guaranteed that when one manganese sand filtering group is shut down, the other manganese sand filtering group continues to work, and the production efficiency is prevented from being affected.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment devices, in particular to a water treatment device for removing iron and manganese. Background Art

[0002] The raw water is well water, and its iron and manganese content exceeds the drinking water standard and needs to be removed. The existing removal methods usually use aeration and oxygenation and manganese sand filtration.

[0003] However, the existing technology has insufficient oxidation effect when treating manganese sand, which easily causes iron and manganese residues. At the same time, the manganese sand filter tank needs to be backwashed regularly, the interval between each backwashing is short, and the manganese sand filter tank needs to be stopped when backwashing, which affects production efficiency. Utility Model Content

[0004] The utility model aims to provide a water treatment device for removing iron and manganese, which solves the technical problem of the shortcomings of the prior art that affect the production efficiency when treating manganese sand.

[0005] The utility model provides a water treatment device for removing iron and manganese, comprising:

[0006] The multi-stage manganese sand filtration group has a pressurized and oxygenated aeration pipeline fixedly connected to its input end, and raw water is introduced into the pressurized and oxygenated aeration pipeline;

[0007] An ozone input pipeline is fixedly connected on the pipeline between the multi-stage manganese sand filtration group and the pressurized and oxygenated aeration pipeline;

[0008] The multi-stage manganese sand filter group includes a first manganese sand filter group and a second manganese sand filter group, and the first manganese sand filter group and the second manganese sand filter group are connected in parallel;

[0009] The input ends of the first manganese sand filter group and the second manganese sand filter group are both fixedly equipped with a first valve;

[0010] The first manganese sand filter group and the second manganese sand filter group are both equipped with a backwashing structure;

[0011] The first manganese sand filter group and the second manganese sand filter group are alternately backwashed.

[0012] As a further optimization scheme, in order to improve the removal effect of iron and manganese through multi-stage filtration, the first manganese sand filtration group and the second manganese sand filtration group have the same structure, and the first manganese sand filtration group is composed of at least three manganese sand filtration tanks.

[0013] As a further optimization scheme, in order to evenly distribute the incoming water to the first manganese sand filter group and the second manganese sand filter group through the first T-shaped three-way joint to reduce the workload of each filter group, the multi-stage manganese sand filter group includes:

[0014] A first T-shaped three-way joint, wherein the input ends of the first manganese sand filter group and the second manganese sand filter group are fixedly connected to both ends of the transverse portion of the first T-shaped three-way joint;

[0015] The output end of the pressurized and oxygenated aeration pipeline is fixedly connected to the longitudinal portion of the first T-shaped three-way connector;

[0016] A second T-shaped three-way joint, wherein the output ends of the first manganese sand filter group and the second manganese sand filter group are fixedly connected to both ends of the transverse portion of the second T-shaped three-way joint;

[0017] The longitudinal portion of the second T-shaped three-way connector is fixedly connected to a drain pipe, and a second valve is fixedly mounted on the drain pipe.

[0018] As a further optimization scheme, in order to backwash the first manganese sand filter group or the second manganese sand filter group, the backwashing structure includes:

[0019] A flushing water inlet pipe, which is fixedly connected to one end of the first manganese sand filter group;

[0020] A flushing drain pipe, which is fixedly connected to the other end of the first manganese sand filter group;

[0021] The flushing water inlet pipe and the flushing drain pipe are both fixedly equipped with a third valve;

[0022] The input end of the flushing water inlet pipe is fixedly connected to a backwashing pump.

[0023] As a further optimization scheme, in order to pressurize and aerate the supplied raw water, the pressurized and oxygenated aeration pipeline includes:

[0024] The explosion water tank and the intermediate water tank are designed as one piece and are interconnected;

[0025] A lifting pump, the output end of which is fixedly connected to the input end of the explosion water tank;

[0026] The output end of the intermediate water tank is fixedly connected to a pressure aeration tank, and the pressure aeration tank is fixedly connected to a pressure pump;

[0027] The output end of the pressure aeration tank is fixedly connected to the input end of the multi-stage manganese sand filter group.

[0028] As a further optimization scheme, in order to use a low-noise Roots blower to blow air and perform oxygenated pre-aeration, a low-noise Roots blower is fixedly connected to the output end of the lift pump.

[0029] As a further optimization solution, in order to discharge the sludge settled at the lower ends of the inner cavities of the aeration water tank and the intermediate water tank, the lower ends of the outer walls of the aeration water tank and the intermediate water tank are fixedly connected to a sludge discharge pump.

[0030] As a further optimization scheme, in order to provide a longer reaction path for the ozone supplied from the output end of the multi-stage manganese sand filter group, it also includes:

[0031] A water reservoir, wherein the output end of the multi-stage manganese sand filter group extends into the water reservoir;

[0032] A multi-stage spiral pipeline comprising:

[0033] A connecting pipe, on which at least two spiral pipeline bodies are fixedly connected;

[0034] The two ends of the connecting pipe are respectively fixedly connected with the input end of the multi-stage manganese sand filtering group and the output end of the pressurized and oxygenated aeration pipeline.

[0035] As a further optimization scheme, in order to adjust the input flow entering the multi-stage manganese sand filter group, a flow valve is fixedly installed on one end of the connecting pipe close to the multi-stage manganese sand filter group.

[0036] As a further optimization solution, in order to shield the upper end of the pool body to prevent impurities from entering, the water reservoir includes:

[0037] The main body of the pool has vertical plates fixedly mounted on both ends of one side of the upper edge;

[0038] A round roller is rotatably connected between the front and rear vertical plates;

[0039] One end of a nylon cloth is wound and fixed on the outer wall of the round roller, and the other end of the nylon cloth is shielded at the upper end of the pool body.

[0040] The utility model provides a water treatment device for removing iron and manganese through improvement, which has the following improvements and advantages compared with the prior art:

[0041] The device adopts a pressurized and oxygenated aeration pipeline for aeration-type pressurized oxygenation, and inputs ozone through an ozone input pipeline to further improve the oxidation effect, so that the iron and manganese in the water are better oxidized and precipitated, and two groups of multi-stage manganese sand filter groups are used to oxidize and filter the iron and manganese in the water to improve the oxidation effect and avoid iron and manganese residues; the two groups of multi-stage manganese sand filter groups share the workload and extend the time interval for backwashing. The first manganese sand filter group and the second manganese sand filter group can be backwashed alternately to ensure that when one manganese sand filter group stops working, the other continues to work to avoid affecting production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 It is a schematic diagram of the structure of the utility model;

[0044] Figure 2 It is a structural schematic diagram of the multi-stage manganese sand filter group and the backwashing structure of the utility model;

[0045] Figure 3 This is a schematic diagram of the structure of the pressurized and oxygenated aeration pipeline of the utility model;

[0046] Figure 4 This is a schematic diagram of the multi-stage spiral pipeline structure of the utility model;

[0047] Figure 5 It is a schematic diagram of the water reservoir structure of the utility model.

[0048] Description of reference numerals:

[0049] 1- pressurized, oxygenated aeration pipeline, 11- explosion water tank, 12- intermediate water tank, 13- lifting pump, 14- pressure aeration tank, 15- pressure pump, 2- multi-stage manganese sand filter group, 21- first manganese sand filter group, 22- second manganese sand filter group, 23- first T-shaped three-way joint, 24- second T-shaped three-way joint, 25- first valve, 26- second valve, 3- multi-stage spiral pipeline, 31- connecting pipe, 32- spiral pipeline body, 33- flow valve, 4- reservoir, 41- reservoir body, 42- vertical plate, 43- round roller, 44- nylon cloth, 5- ozone input pipeline, 6- low noise Roots blower, 7- mud pump, 8- backwashing structure, 81- flushing water inlet pipe, 82- backwashing pump, 83- flushing drain pipe, 84- third valve. DETAILED DESCRIPTION

[0050] The technical solution of the utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0051] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0052] In the description of the present utility model, it should be understood that the terms "first" and "second" are only used for descriptive purposes, and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0053] See also Figure 1-5 The utility model provides a technical solution: a water treatment device for removing iron and manganese, comprising:

[0054] The multi-stage manganese sand filter group 2 has an input end fixedly connected to a pressurized and oxygenated aeration pipeline 1, and raw water is introduced into the pressurized and oxygenated aeration pipeline 1, and the pressurized and oxygenated aeration pipeline 1 performs pre-aeration and high-pressure aeration and oxygenation;

[0055] An ozone input pipeline 5 is fixedly connected to the pipeline between the multi-stage manganese sand filter group 2 and the pressurized and oxygenated aeration pipeline 1. The ozone input pipeline 5 is used to supply ozone to the oxygenated aeration pipeline 1 to improve the oxidation effect. The ozone input pipeline 5 is supplied with ozone through a mixing pump;

[0056] The multi-stage manganese sand filter group 2 includes a first manganese sand filter group 21 and a second manganese sand filter group 22, the first manganese sand filter group 21 and the second manganese sand filter group 22 are connected in parallel, and the supplied raw water is evenly diverted by the first manganese sand filter group 21 and the second manganese sand filter group 22, thereby reducing the workload of a single manganese sand filter group;

[0057] The first manganese sand filter group 21 and the second manganese sand filter group 22 are both fixedly equipped with a first valve 25;

[0058] The first manganese sand filter group 21 and the second manganese sand filter group 22 are both equipped with a backwashing structure 8;

[0059] The first manganese sand filter group 21 and the second manganese sand filter group 22 are backwashed alternately.

[0060] When back flushing is required, close any first valve 25 on the first manganese sand filter group 21 and the second manganese sand filter group 22, and open the back flushing structure 8 on the manganese sand filter group corresponding to the first valve 25 to back flush the manganese sand filter group; then open the closed first valve 25 and the back flushing structure 8, open the first valve 25 and the back flushing structure 8 on the other manganese sand filter group, and back flush the manganese sand filter group. The first manganese sand filter group 21 and the second manganese sand filter group 22 are back flushed alternately to ensure that one manganese sand filter group is in working condition.

[0061] In some embodiments, in order to improve the removal effect of iron and manganese through multi-stage filtration, the first manganese sand filtration group 21 and the second manganese sand filtration group 22 have the same structure, and the first manganese sand filtration group 21 is composed of at least three manganese sand filtration tanks.

[0062] The first manganese sand filter group 21 and the second manganese sand filter group 22 are divided into six tanks, two groups, three tanks are connected in series, and two groups are connected in parallel. The manganese sand filter tanks are filled with manganese sand with a manganese dioxide content exceeding 30%.

[0063] In some embodiments, in order to evenly distribute the incoming water to the first manganese sand filter group 21 and the second manganese sand filter group 22 through the first T-shaped three-way connector 23 and reduce the workload of each filter group, the multi-stage manganese sand filter group 2 includes:

[0064] The first T-shaped three-way connector 23, the input ends of the first manganese sand filter group 21 and the second manganese sand filter group 22 are fixedly connected with both ends of the transverse portion of the first T-shaped three-way connector 23;

[0065] The output end of the pressurized and oxygenated aeration pipeline 1 is fixedly connected to the longitudinal portion of the first T-shaped three-way connector 23;

[0066] A second T-shaped three-way connector 24, the output ends of the first manganese sand filter group 21 and the second manganese sand filter group 22 are fixedly connected to both ends of the transverse portion of the second T-shaped three-way connector 24;

[0067] The longitudinal portion of the second T-shaped three-way connector 24 is fixedly connected to a drainage pipe, and a second valve 26 is fixedly mounted on the drainage pipe. The second valve 26 controls the output of the multi-stage manganese sand filter group 2.

[0068] In some embodiments, in order to backwash the first manganese sand filter group 21 or the second manganese sand filter group 22, the backwashing structure 8 includes:

[0069] A flushing water inlet pipe 81, which is fixedly connected to one end of the first manganese sand filter group 21;

[0070] A flushing drain pipe 83, which is fixedly connected to the other end of the first manganese sand filter group 21;

[0071] A third valve 84 is fixedly mounted on the flushing water inlet pipe 81 and the flushing drain pipe 83;

[0072] The input end of the flushing water inlet pipe 81 is fixedly connected to a backwashing pump 82 .

[0073] When in use, open the third valve 84 on the flushing water inlet pipe 81 and the flushing drain pipe 83, close the first valve 25, and then start the backwashing pump 82 to reversely supply external water source into the first manganese sand filter group 21 or the second manganese sand filter group 22 for reverse flushing. The flushing waste water is discharged from the flushing drain pipe 83, and the valves are reset after flushing.

[0074] In some embodiments, in order to pressurize and aerate the supplied raw water, the pressurized and oxygenated aeration pipeline 1 includes:

[0075] The explosion water tank 11 and the intermediate water tank 12 are integrally designed and interconnected;

[0076] A lifting pump 13, whose output end is fixedly connected to the input end of the explosion water tank 11, and the lifting pump 13 is used to supply raw water to the explosion water tank 11;

[0077] The output end of the intermediate water tank 12 is fixedly connected to a pressure aeration tank 14, and the pressure aeration tank 14 is fixedly connected to a booster pump 15, which is used to pressurize aeration in the pressure aeration tank 14;

[0078] The output end of the pressure aeration tank 14 is fixedly connected to the input end of the multi-stage manganese sand filter group 2 .

[0079] The water in the intermediate water tank 12 is sent to the pressure aeration tank through the pressure pump 15, and compressed air is introduced for pressurized aeration, and then passes through the first-level manganese sand filter tank, then the second-level manganese sand filter tank, and finally to the third-level manganese sand filter tank. Under the catalytic action of MnO2 in the manganese sand, the iron and manganese oxides in the water are precipitated and attached to the surface of the manganese sand.

[0080] In some embodiments, in order to blow air through the low-noise Roots blower 6 for oxygenated pre-aeration, the output end of the lift pump 13 is fixedly connected with the low-noise Roots blower 6, and the low-noise Roots blower 6 is used to blow air into the explosion water tank 11 for oxygenated pre-explosion.

[0081] In some embodiments, in order to discharge the sludge deposited at the lower ends of the inner cavities of the aeration water tank 11 and the intermediate water tank 12 , the lower ends of the outer walls of the aeration water tank 11 and the intermediate water tank 12 are fixedly connected to a sludge discharge pump 7 .

[0082] In some embodiments, in order to provide a longer reaction path for the ozone supplied from the output end of the multi-stage manganese sand filter group 2, it also includes:

[0083] Reservoir 4, the output end of the multi-stage manganese sand filter group 2 extends into the reservoir 4, and the reservoir 4 is 300m 3 ;

[0084] The multi-stage spiral pipeline 3 comprises:

[0085] The connecting pipe 31 has at least two spiral pipeline bodies 32 fixedly connected thereon. The reaction path of ozone and raw water is extended by multiple groups of spiral pipeline bodies 32 connected in series. The two ends of the connecting pipe 31 are fixedly connected to the input end of the multi-stage manganese sand filtration group 2 and the output end of the pressurized and oxygenated aeration pipeline 1 respectively.

[0086] In some embodiments, in order to adjust the input flow entering the multi-stage manganese sand filter group 2, a flow valve 33 is fixedly installed on one end of the connecting pipe 31 close to the multi-stage manganese sand filter group 2, and the flow input flow of raw water entering the multi-stage manganese sand filter group 2 is controlled by the flow adjustment of the flow valve 33.

[0087] In some embodiments, in order to shield the upper end of the pool body 41 and prevent impurities from entering, the water reservoir 4 includes:

[0088] The pool body 41 has vertical plates 42 fixedly mounted on both ends of one side of the upper edge;

[0089] A round roller 43 is rotatably connected between the front and rear vertical plates 42;

[0090] One end of a nylon cloth 44 is wound and fixed on the outer wall of the round roller 43 , and the other end of the nylon cloth 44 blocks the upper end of the pool body 41 . The nylon cloth 44 can be rolled up on the outer wall of the round roller 43 to remove the blocking of the upper end of the pool body 41 .

[0091] The pipes in the device are made of UPVC, and the valves are stainless steel pneumatic butterfly valves. Automatic control is achieved through the 4 water levels of the reservoir and the lower and upper limits of the water levels in each level of the water tank to realize the automatic start and stop of the water treatment device.

[0092] Working principle:

[0093] Raw water is introduced into the pressurized and oxygenated aeration pipeline 1, and the pressurized and oxygenated aeration pipeline 1 performs pre-aeration and high-pressure aeration and oxygenation. The ozone input pipeline 5 is used to supply ozone to the oxygenated aeration pipeline 1 to improve the oxidation effect. The ozone input pipeline 5 supplies ozone through a mixing pump;

[0094] The first manganese sand filter group 21 and the second manganese sand filter group 22 are connected in parallel, and the raw water supplied is evenly diverted by the first manganese sand filter group 21 and the second manganese sand filter group 22, thereby reducing the workload of a single manganese sand filter group;

[0095] When back flushing is required, close any first valve 25 on the first manganese sand filter group 21 and the second manganese sand filter group 22, and open the back flushing structure 8 on the manganese sand filter group corresponding to the first valve 25 to back flush the manganese sand filter group; then open the closed first valve 25 and the back flushing structure 8, open the first valve 25 and the back flushing structure 8 on the other manganese sand filter group, and back flush the manganese sand filter group. The first manganese sand filter group 21 and the second manganese sand filter group 22 are back flushed alternately to ensure that one manganese sand filter group is in working condition.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A water treatment device for removing iron and manganese, characterized in that: include: The multi-stage manganese sand filtration group (2) has an input end fixedly connected to a pressurized and oxygenated aeration pipeline (1), and raw water is introduced into the pressurized and oxygenated aeration pipeline (1); An ozone input pipeline (5) is fixedly connected to the pipeline between the multi-stage manganese sand filtration group (2) and the pressurized and oxygenated aeration pipeline (1); The multi-stage manganese sand filter group (2) comprises a first manganese sand filter group (21) and a second manganese sand filter group (22), and the first manganese sand filter group (21) and the second manganese sand filter group (22) are connected in parallel; The input ends of the first manganese sand filter group (21) and the second manganese sand filter group (22) are both fixedly equipped with a first valve (25); The first manganese sand filter group (21) and the second manganese sand filter group (22) are both equipped with a backwashing structure (8); The first manganese sand filter group (21) and the second manganese sand filter group (22) are alternately backwashed.

2. A water treatment device for removing iron and manganese according to claim 1, characterized in that: The first manganese sand filter group (21) and the second manganese sand filter group (22) have the same structure, and the first manganese sand filter group (21) is composed of at least three manganese sand filter tanks.

3. A water treatment device for removing iron and manganese according to claim 1, characterized in that: The multi-stage manganese sand filtration group (2) comprises: A first T-shaped three-way connector (23), wherein the input ends of the first manganese sand filter group (21) and the second manganese sand filter group (22) are fixedly connected to both ends of the transverse portion of the first T-shaped three-way connector (23); The output end of the pressurized and oxygenated aeration pipeline (1) is fixedly connected to the longitudinal portion of the first T-shaped three-way connector (23); A second T-shaped three-way connector (24), wherein the output ends of the first manganese sand filter group (21) and the second manganese sand filter group (22) are fixedly connected to both ends of the transverse portion of the second T-shaped three-way connector (24); The longitudinal portion of the second T-shaped three-way connector (24) is fixedly connected to a drainage pipe, and a second valve (26) is fixedly mounted on the drainage pipe.

4. A water treatment device for removing iron and manganese according to claim 3, characterized in that: The backwashing structure (8) comprises: A flushing water inlet pipe (81) fixedly connected to one end of the first manganese sand filter group (21); A flushing drain pipe (83) fixedly connected to the other end of the first manganese sand filter group (21); The flushing water inlet pipe (81) and the flushing drain pipe (83) are both fixedly mounted with a third valve (84); The input end of the flushing water inlet pipe (81) is fixedly connected to a backwashing pump (82).

5. The water treatment device for removing iron and manganese according to claim 1, characterized in that: The pressurized and oxygenated aeration pipeline (1) comprises: The explosion water tank (11) and the intermediate water tank (12) are integrally designed and interconnected; A lifting pump (13), the output end of which is fixedly connected to the input end of the explosion water tank (11); The output end of the intermediate water tank (12) is fixedly connected to a pressure aeration tank (14), and the pressure aeration tank (14) is fixedly connected to a pressure pump (15); The output end of the pressure aeration tank (14) is fixedly connected to the input end of the multi-stage manganese sand filter group (2).

6. A water treatment device for removing iron and manganese according to claim 5, characterized in that: The output end of the lift pump (13) is fixedly connected to a low-noise Roots blower (6).

7. A water treatment device for removing iron and manganese according to claim 5, characterized in that: The lower ends of the outer walls of the explosion water tank (11) and the intermediate water tank (12) are both fixedly connected to a mud discharge pump (7).

8. The water treatment device for removing iron and manganese according to claim 1, characterized in that: Also includes, A water reservoir (4), wherein the output end of the multi-stage manganese sand filter group (2) extends into the water reservoir (4); A multi-stage spiral pipeline (3), comprising: A connecting pipe (31) on which at least two spiral pipeline bodies (32) are fixedly connected; The two ends of the connecting pipe (31) are respectively fixedly connected to the input end of the multi-stage manganese sand filtration group (2) and the output end of the pressurized and oxygenated aeration pipeline (1).

9. A water treatment device for removing iron and manganese according to claim 8, characterized in that: A flow valve (33) is fixedly mounted on one end of the connecting pipe (31) close to the multi-stage manganese sand filtering group (2).

10. The water treatment device for removing iron and manganese according to claim 8, characterized in that: The water reservoir (4) comprises: The pool body (41) has vertical plates (42) fixedly mounted on both ends of one side of the upper edge; A round roller (43) is rotatably connected between the front and rear vertical plates (42); One end of a nylon cloth (44) is wound and fixed on the outer wall of the circular roller (43), and the other end of the nylon cloth (44) is shielded from the upper end of the pool body (41).

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