Anti-blocking sewage recovery system

Abstract

The utility model relates to the technical field of concrete sewage treatment, in particular to an anti-blocking sewage recovery system. The sewage recycling system comprises a stirring pool / tank, a stirring station clean water pool / box, and a sewage recycling loop and a clean water backflushing loop which are connected with the stirring pool / tank and the stirring station clean water pool / box, wherein the sewage recycling loop comprises a recycling water pump, a stirring station sewage scale and a sewage recycling pipeline which is connected with the recycling water pump and the stirring station sewage scale; the clean water back-flushing loop comprises a mixing plant clean water pump and a clean water back-flushing pipeline connected with the mixing plant clean water pump; in addition, the pneumatic butterfly valve I, the pneumatic butterfly valve II and the pneumatic butterfly valve III are respectively connected with an air compressor. And the air compressor, the recycling water pump, the mixing plant clean water pump and the mixing plant sewage scale are respectively connected with the control cabinet. According to the utility model, through regular or irregular clear water back-flushing cleaning, attachments in the sewage recovery pipeline are effectively cleaned, the phenomena of pipeline blockage and wall attachment are prevented, and the service life of the pipeline is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of concrete sewage treatment, in particular to an anti-clogging sewage recovery system. Background Art

[0002] With the rapid development of society, the construction industry has been advancing by leaps and bounds, and the concrete mixing industry has also made great progress. Energy conservation and environmental protection have always been problems that need to be solved in mixing stations. The traditional sewage recovery method frequently causes problems of wall clogging on the inner wall of the pipe after long-term use. The daily maintenance is complicated, which seriously affects the normal operation of the mixing station. Now, an anti-clogging sewage recovery system and method are added to solve the above problems, reduce or even eliminate the occurrence of wall clogging on the inner wall of the pipe and the pipe clogging, and ensure the normal use of the equipment. In order to solve the above technical problems, technical personnel in this field have made the following efforts. For example, a Chinese patent, the authorization announcement number is CN212315588U, which discloses a sewage treatment device for a mixing station, which includes a clean water tank, a sewage tank, a regulating tank and an electrical control box. A clean water pump is provided in the clean water tank, one end of the clean water pipeline is connected to the clean water pump, and the other end is connected to the regulating tank. However, the above scheme still has certain low work efficiency problems for the effective recovery and reuse of sewage generated during the mixing process. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide an anti-clogging sewage recovery system.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A clogging-proof sewage recovery system comprises a mixing tank / tank, a mixing station clean water tank / tank, and a sewage recovery circuit and a clean water backwash circuit connecting the mixing tank / tank and the mixing station clean water tank / tank, wherein:

[0006] The sewage recovery circuit includes a recovery water pump arranged at the bottom of the mixing tank / tank, a sewage scale of the mixing station, and a sewage recovery pipeline connecting the recovery water pump and the sewage scale of the mixing station. Pneumatic butterfly valves I and II are installed on the sewage recovery pipeline;

[0007] The clean water backwash circuit includes a clean water pump of the mixing station arranged at the bottom of the clean water tank / tank of the mixing station, and a clean water backwash pipeline connected to the clean water pump of the mixing station, the outlet of the clean water backwash pipeline is connected between the pneumatic butterfly valve I and the pneumatic butterfly valve II, and the pneumatic butterfly valve III and a one-way / check valve are installed on the clean water backwash pipeline;

[0008] In addition, pneumatic butterfly valve I, pneumatic butterfly valve II and pneumatic butterfly valve III are respectively connected to the air compressor; the air compressor, recovery water pump, mixing station clean water pump and mixing station sewage scale are respectively connected to the control cabinet.

[0009] This technical solution realizes the effective recovery and reuse of the sewage generated during the mixing process through the sewage recovery circuit and the clean water backwash circuit, while avoiding the problem of pipeline blockage. It has the characteristics of energy saving, environmental protection, intelligence and high degree of automation. Specifically, the generated sewage is collected at the bottom of the mixing tank / tank. After the recovery water pump is started, the sewage is extracted from the bottom of the mixing tank / tank and transported to the mixing station sewage scale through the sewage recovery pipeline for centralized treatment or reuse; the pneumatic butterfly valve I and pneumatic butterfly valve II installed on the sewage recovery pipeline control the flow of sewage by controlling their opening and closing states. The pneumatic butterfly valve I and pneumatic butterfly valve II are closed when necessary to cut off the flow of sewage, such as when performing clean water backwashing; in order to prevent the sewage recovery pipeline from being blocked due to long-term use or accumulation of impurities in the sewage, a clean water backwash circuit is added; when it is necessary to clean the pipeline, the pneumatic butterfly valve II is closed, the pneumatic butterfly valve III is opened, and the mixing station clean water pump is started; the clean water pump extracts clean water from the clean water tank / tank of the mixing station, and reversely flushes the sewage recovery pipeline through the clean water backwash pipeline, thereby removing impurities in the pipeline. and blockages; the outlet of the clean water backwash pipeline is connected between pneumatic butterfly valve I and pneumatic butterfly valve II to ensure that clean water can only flow in this direction to prevent sewage from flowing back into the clean water tank / box; pneumatic butterfly valve I, pneumatic butterfly valve II and pneumatic butterfly valve III are opened and closed by the air source provided by the air compressor, with fast response speed, suitable for situations where the fluid needs to be quickly cut off or connected; the control cabinet automatically adjusts the operating status of each device according to the signal feedback from the sensor to realize the intelligent management of sewage recovery and clean water backwashing; by recycling the sewage generated during the mixing process and transporting it to the sewage scale of the mixing station for reuse, the consumption of fresh water is reduced, the production cost is reduced, and it also meets environmental protection requirements; the sewage recovery pipeline is regularly cleaned through the clean water backwash circuit to keep the pipeline unobstructed, extend the service life of the pipeline, and reduce maintenance costs.

[0010] In addition, the anti-clogging sewage recovery system proposed in the utility model also has the following additional technical features:

[0011] According to one embodiment of the utility model, liquid level sensors for monitoring liquid levels are provided in the mixing tank / tank and the mixing station clean water tank / box. The liquid level sensors are connected to a control cabinet, and the control cabinet controls the recovery water pump and the mixing station clean water pump to sound an alarm.

[0012] This technical solution reduces the tediousness and errors of manual operation and improves work efficiency through the linkage between the liquid level sensor and the control cabinet. When the liquid level in the mixing tank / tank reaches or exceeds the preset high liquid level threshold, the control cabinet will start the recovery water pump to transport the sewage through the sewage recovery pipeline to the mixing station sewage scale for treatment or reuse. This avoids overflow of the mixing tank / tank and ensures timely treatment of sewage. Similarly, when the liquid level of the mixing station clear water tank / tank is lower than the preset low liquid level threshold, the control cabinet will start the mixing station clear water pump to draw clear water from the clear water source and replenish it in the clear water tank / tank to ensure the continuity of the clear water supply.

[0013] According to an embodiment of the utility model, a pressure sensor for monitoring the change of sewage pressure in the pipeline to prevent blockage is installed on the sewage recovery pipeline, and the pressure sensor is connected to the control cabinet.

[0014] This technical solution monitors the pressure changes in the sewage recovery pipeline in real time, and uses pressure sensors and control cabinets to effectively prevent and solve problems such as pipeline blockage. The pressure sensor can measure the pressure value of sewage in the recovery pipeline in real time. When sewage flows in the pipeline, the pressure will change due to friction, bending, valve opening / closing and other factors. The control cabinet will trigger the alarm mechanism to remind the operator to check and repair. The alarm method is sound and light alarm, SMS notification, email reminder, etc.

[0015] According to an embodiment of the utility model, a filter and a screen are provided at the inlet of the sewage recovery pipeline to reduce the risk of pipeline blockage.

[0016] This technical solution reduces the risk of pipeline blockage through filtering and screening, and improves the operating efficiency, reliability and environmental protection of the sewage recovery system; through the dual effects of the filter and the screen, most of the impurities that can cause pipeline blockage are effectively intercepted, thereby greatly reducing the risk of pipeline blockage; the filter and the screen are usually designed as a detachable structure, which is convenient for regular cleaning and maintenance. When the accumulated impurities reach a certain level, they can be easily removed and cleaned to ensure the continued effectiveness of the filtering and screening effects.

[0017] According to one embodiment of the utility model, an overflow valve is arranged on the top of the stirring pool / tank, and a sewage / water valve is arranged on the bottom.

[0018] In this technical solution, during the mixing process, if the amount of liquid or concrete exceeds the capacity of the mixing tank / tank, the overflow valve will open in time to discharge the excess liquid or material to prevent it from overflowing and causing waste or pollution. The sewage / water valve is located at the bottom of the mixing tank / tank and is mainly used to discharge sewage, impurities or residues accumulated at the bottom.

[0019] According to one embodiment of the utility model, when the pneumatic butterfly valve I and the pneumatic butterfly valve II are opened and the pneumatic butterfly valve III is closed, the system is in a sewage recovery state; when the pneumatic butterfly valve I and the pneumatic butterfly valve III are opened and the pneumatic butterfly valve II is closed, the system is in a clean water backwash state.

[0020] In this technical solution, in the sewage recovery state, the opening of pneumatic butterfly valve I and pneumatic butterfly valve II allows sewage to enter from the sewage recovery pipeline and be sent to the sewage scale of the mixing station; the closing of pneumatic butterfly valve III blocks the entry of clean water or other fluids to ensure that other fluids will not be mixed in the sewage recovery process. In the clean water backwash state, the opening of pneumatic butterfly valve I allows clean water to enter from the clean water backwash pipeline, and the opening of pneumatic butterfly valve III allows clean water to flow to the part that needs to be cleaned or backwashed; the closing of pneumatic butterfly valve II blocks the entry of sewage or other unnecessary fluids to ensure that impurities or pollutants will not be mixed in the clean water backwash process.

[0021] Compared with the prior art, the utility model has the following beneficial effects:

[0022] (1) Through the sewage recovery loop and the clean water backwash loop, the sewage generated during the mixing process can be effectively recovered and reused, which has the characteristics of energy saving, environmental protection, intelligence and high degree of automation.

[0023] (2) Through regular or irregular backwash cleaning with clean water, the attachments in the sewage recovery pipeline can be effectively cleaned, the pipeline blockage and wall formation can be prevented, and the service life of the pipeline can be extended. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the utility model.

[0025] In the figure: 1. Mixing tank / tank; 2. Recovery water pump; 3. Pneumatic butterfly valve III; 4. Sewage recovery pipeline; 5. Pneumatic butterfly valve I; 6. Clean water backwash pipeline; 7. Pneumatic butterfly valve II; 8. One-way / check valve; 9. Clean water tank / tank of mixing station; 10. Clean water pump of mixing station; 11. Sewage scale of mixing station; 12. Air compressor; 13. Control cabinet. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. 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.

[0027] Example 1

[0028] like Figure 1As shown, this embodiment provides an anti-clogging sewage recovery system, including a mixing tank / tank 1, a mixing station clean water tank / tank 9, and a sewage recovery circuit and a clean water backwash circuit connecting the mixing tank / tank 1 and the mixing station clean water tank / tank 9, wherein:

[0029] The sewage recovery circuit includes a recovery water pump 2 disposed at the bottom of the mixing tank / tank 1, a mixing station sewage scale 11, and a sewage recovery pipeline 4 connecting the recovery water pump 2 and the mixing station sewage scale 11, and a pneumatic butterfly valve Ⅰ5 and a pneumatic butterfly valve Ⅱ7 are installed on the sewage recovery pipeline 4;

[0030] The clean water backwash circuit includes a mixing station clean water pump 10 disposed at the bottom of a mixing station clean water tank / tank 9, and a clean water backwash pipeline 6 connected to the mixing station clean water pump 10, the outlet of the clean water backwash pipeline 6 is connected between a pneumatic butterfly valve I5 and a pneumatic butterfly valve II7, and a pneumatic butterfly valve III3 and a one-way / check valve 8 are installed on the clean water backwash pipeline 6;

[0031] In addition, pneumatic butterfly valve I5, pneumatic butterfly valve II7 and pneumatic butterfly valve III3 are respectively connected to the air compressor 12; the air compressor 12, the recovery water pump 2, the mixing station clean water pump 10 and the mixing station sewage scale 11 are respectively connected to the control cabinet 13.

[0032] like Figure 1As shown, this technical solution realizes the effective recovery and reuse of sewage generated during the mixing process through sewage recovery circuit and clean water backwash circuit, while avoiding the problem of pipeline blockage. It has the characteristics of energy saving, environmental protection, intelligence and high degree of automation. Specifically, the generated sewage is collected at the bottom of the mixing tank / tank 1. After the recovery water pump 2 is started, the sewage is extracted from the bottom of the mixing tank / tank 1 and transported to the mixing station sewage scale 11 through the sewage recovery pipeline 4 for centralized treatment or reuse; the pneumatic butterfly valve I5 and the pneumatic butterfly valve II7 installed on the sewage recovery pipeline 4 control the flow of sewage by controlling their opening and closing states. The pneumatic butterfly valve I5 and the pneumatic butterfly valve II7 are closed when necessary to cut off the flow of sewage, such as when performing clean water backwashing; in order to prevent the sewage recovery pipeline 4 from being blocked due to long-term use or accumulation of impurities in the sewage, a clean water backwashing circuit is added; when it is necessary to clean the pipeline, the pneumatic butterfly valve II7 is closed, the pneumatic butterfly valve III3 is opened, and the mixing station clean water pump 10 is started; the clean water pump extracts clean water from the clean water tank / tank 9 of the mixing station, and backwashes the sewage recovery pipeline 4 through the clean water backwash pipeline 6, thereby clearing the pipeline. impurities and blockages; the outlet of the clean water backwash pipeline 6 is connected between the pneumatic butterfly valve Ⅰ5 and the pneumatic butterfly valve Ⅱ7 to ensure that the clean water can only flow in this direction to prevent the sewage from flowing back into the clean water tank / box; the pneumatic butterfly valve Ⅰ5, the pneumatic butterfly valve Ⅱ7 and the pneumatic butterfly valve Ⅲ3 are opened and closed by the air source provided by the air compressor 12, with a fast response speed, which is suitable for situations where the fluid needs to be quickly cut off or connected; the control cabinet 13 automatically adjusts the operating status of each device according to the signal fed back by the sensor to realize the intelligent management of sewage recovery and clean water backwashing; by recycling the sewage generated during the mixing process and transporting it to the mixing station sewage scale 11 for reuse, the consumption of fresh water is reduced, the production cost is reduced, and it also meets the environmental protection requirements; the sewage recovery pipeline 4 is regularly cleaned through the clean water backwash circuit to keep the pipeline unobstructed, extend the service life of the pipeline, and reduce maintenance costs.

[0033] In addition, the anti-clogging sewage recovery system proposed in the utility model also has the following additional technical features:

[0034] According to one embodiment of the utility model, liquid level sensors for monitoring liquid levels are provided in the mixing pool / tank 1 and the mixing station clean water pool / tank 9. The liquid level sensors are connected to the control cabinet 13. The control cabinet 13 controls the recovery water pump 2 and the mixing station clean water pump 10 to issue an alarm.

[0035] This technical solution reduces the tediousness and errors of manual operation and improves work efficiency through the linkage between the liquid level sensor and the control cabinet 13. When the liquid level in the mixing tank / tank 1 reaches or exceeds the preset high liquid level threshold, the control cabinet 13 will start the recovery water pump 2 to transport the sewage through the sewage recovery pipeline 4 to the mixing station sewage scale 11 for treatment or reuse. This avoids overflow of the mixing tank / tank 1 and ensures timely treatment of sewage. Similarly, when the liquid level of the mixing station clean water tank / tank 9 is lower than the preset low liquid level threshold, the control cabinet 13 will start the mixing station clean water pump 10 to draw clean water from the clean water source and replenish it in the clean water tank / tank to ensure the continuity of the clean water supply.

[0036] According to an embodiment of the utility model, a pressure sensor for monitoring the change of sewage pressure in the pipeline to prevent blockage is installed on the sewage recovery pipeline 4, and the pressure sensor is connected to the control cabinet 13.

[0037] This technical solution effectively prevents and solves problems such as pipeline blockage by monitoring the pressure changes in the sewage recovery pipeline 4 in real time, and using the pressure sensor and the control cabinet 13. The pressure sensor can measure the pressure value of the sewage in the recovery pipeline in real time. When the sewage flows in the pipeline, the pressure will change due to factors such as friction, bending, valve opening / closing, etc. The control cabinet 13 will trigger the alarm mechanism to remind the operator to check and repair. The alarm method is sound and light alarm, SMS notification, email reminder, etc.

[0038] According to an embodiment of the present invention, a filter and a screen are provided at the inlet of the sewage recovery pipeline 4 to reduce the risk of pipeline blockage.

[0039] This technical solution reduces the risk of pipeline blockage through filtering and screening, and improves the operating efficiency, reliability and environmental protection of the sewage recovery system; through the dual effects of the filter and the screen, most of the impurities that can cause pipeline blockage are effectively intercepted, thereby greatly reducing the risk of pipeline blockage; the filter and the screen are usually designed as a detachable structure, which is convenient for regular cleaning and maintenance. When the accumulated impurities reach a certain level, they can be easily removed and cleaned to ensure the continued effectiveness of the filtering and screening effects.

[0040] According to one embodiment of the utility model, an overflow valve is arranged at the top of the stirring pool / tank 1, and a sewage / water valve is arranged at the bottom.

[0041] In this technical solution, during the mixing process, if the amount of liquid or concrete exceeds the capacity of the mixing tank / tank 1, the overflow valve will open in time to discharge the excess liquid or material to prevent it from overflowing and causing waste or pollution. The sewage / water valve is located at the bottom of the mixing tank / tank 1 and is mainly used to discharge sewage, impurities or residues accumulated at the bottom.

[0042] According to one embodiment of the utility model, when the pneumatic butterfly valve I5 and the pneumatic butterfly valve II7 are opened and the pneumatic butterfly valve III3 is closed, the system is in a sewage recovery state; when the pneumatic butterfly valve I5 and the pneumatic butterfly valve III3 are opened and the pneumatic butterfly valve II7 is closed, the system is in a clean water backwash state.

[0043] In this technical solution, in the sewage recovery state, the opening of pneumatic butterfly valve I5 and pneumatic butterfly valve II7 allows sewage to enter from the sewage recovery pipeline 4 and be sent to the mixing station sewage scale 11; the closing of pneumatic butterfly valve III3 blocks the entry of clean water or other fluids to ensure that other fluids will not be mixed in the sewage recovery process. In the clean water backwash state, the opening of pneumatic butterfly valve I5 allows clean water to enter from the clean water backwash pipeline 6, and the opening of pneumatic butterfly valve III3 allows clean water to flow to the part that needs to be cleaned or backwashed; the closing of pneumatic butterfly valve II7 blocks the entry of sewage or other unnecessary fluids to ensure that impurities or pollutants will not be mixed in the clean water backwash process.

[0044] The usage process of the above embodiment is as follows:

[0045] like Figure 1 As shown, when sewage is generated during the concrete mixing process, the sewage is pumped into the sewage recovery pipeline 4 through the recovery water pump 2, and finally flows to the mixing station sewage scale 11 for centralized treatment or reuse; in order to prevent the sewage recovery pipeline 4 from being blocked due to long-term use or accumulation of impurities in the sewage, the system introduces a clean water backwash mechanism; when the system detects that the pipeline is blocked or needs maintenance, the pneumatic butterfly valve II 7 is closed through the operation of the control cabinet 13, and the pneumatic butterfly valve I 5 and the pneumatic butterfly valve III 3 are opened at the same time, and the mixing station clean water pump 10 is started; the clean water pump pumps the clean water in the mixing station clean water tank / tank 9 into the sewage recovery pipeline 4 through the clean water backwash pipeline 6, and uses high-pressure clean water to flush the inner wall of the pipeline to remove attached impurities and blockages; the one-way / check valve 8 ensures that the clean water can only flow in one direction to prevent the sewage from flowing back into the clean water tank / tank; the pneumatic butterfly valve Ⅰ5, pneumatic butterfly valve Ⅱ7 and pneumatic butterfly valve Ⅲ3 are opened and closed by the air source provided by the air compressor 12; the control cabinet 13 automatically or manually controls the opening and closing of the pneumatic butterfly valve according to the working state of the system and the preset cleaning cycle, so as to realize the switching between sewage recovery and clean water backwashing; the control cabinet 13 serves as the control center of the whole system, receiving sensor signals from various parts, such as pressure, flow, liquid level, etc., and automatically adjusts the working state of the system according to these signals; the control cabinet 13 realizes the intelligent management of the sewage recovery system, including automatic detection, automatic cleaning, automatic alarm and other functions; through effective sewage recovery and reuse, the system reduces the consumption of fresh water and the discharge of sewage, and meets the requirements of energy conservation and environmental protection; the clean water backwashing mechanism can regularly clean the pipeline, extend the service life of the pipeline, and reduce maintenance costs.

[0046] Although the utility model is described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the utility model is not limited thereto. Without departing from the spirit and essence of the utility model, ordinary technicians in the field can make various equivalent modifications or substitutions to the embodiments of the utility model, and these modifications or substitutions should be within the scope of the utility model / any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the protection scope of the claims.

Claims

1. An anti-clogging sewage recovery system, characterized in that: It comprises a mixing tank / tank (1), a mixing station clean water tank / tank (9), and a sewage recovery circuit and a clean water backwash circuit connecting the mixing tank / tank (1) and the mixing station clean water tank / tank (9), wherein: A sewage recovery circuit comprises a recovery water pump (2) arranged at the bottom of a mixing tank / tank (1), a mixing station sewage scale (11), and a sewage recovery pipeline (4) connecting the recovery water pump (2) and the mixing station sewage scale (11), wherein a pneumatic butterfly valve I (5) and a pneumatic butterfly valve II (7) are installed on the sewage recovery pipeline (4); A clean water backwash circuit comprises a mixing station clean water pump (10) arranged at the bottom of a mixing station clean water tank / box (9), and a clean water backwash pipeline (6) connected to the mixing station clean water pump (10), wherein the outlet of the clean water backwash pipeline (6) is connected between a pneumatic butterfly valve I (5) and a pneumatic butterfly valve II (7), and a pneumatic butterfly valve III (3) and a one-way / check valve (8) are installed on the clean water backwash pipeline (6); In addition, the pneumatic butterfly valve I (5), the pneumatic butterfly valve II (7) and the pneumatic butterfly valve III (3) are respectively connected to the air compressor (12); the air compressor (12), the recovery water pump (2), the mixing station clean water pump (10) and the mixing station sewage scale (11) are respectively connected to the control cabinet (13).

2. The anti-clogging sewage recovery system according to claim 1, characterized in that: The mixing tank / tank (1) and the mixing station clean water tank / tank (9) are provided with liquid level sensors for monitoring the liquid level. The liquid level sensors are connected to a control cabinet (13). The control cabinet (13) controls the recovery water pump (2) and the mixing station clean water pump (10) to issue an alarm.

3. The anti-clogging sewage recovery system according to claim 1, characterized in that: The sewage recovery pipeline (4) is provided with a pressure sensor for monitoring the change of sewage pressure in the pipeline to prevent blockage, and the pressure sensor is connected to the control cabinet (13).

4. The anti-clogging sewage recycling system according to claim 1, characterized in that: A filter and a screen are provided at the inlet of the sewage recovery pipeline (4) to reduce the risk of pipeline blockage.

5. The anti-clogging sewage recovery system according to claim 1 or 2, characterized in that: The top of the stirring tank / tank (1) is provided with an overflow valve, and the bottom is provided with a sewage / water valve.

6. The anti-clogging sewage recycling system according to claim 1, characterized in that: When the pneumatic butterfly valve I (5) and the pneumatic butterfly valve II (7) are opened and the pneumatic butterfly valve III (3) is closed, the system is in a sewage recovery state; when the pneumatic butterfly valve I (5) and the pneumatic butterfly valve III (3) are opened and the pneumatic butterfly valve II (7) is closed, the system is in a clean water backwash state.

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