Backwashing system of biological aerated filter

Abstract

The utility model relates to the technical field of sewage treatment, in particular to a backwashing system of a biological aerated filter, which comprises a filter body and a backwashing air pipe connected to the filter body, and the end part of the backwashing air pipe is connected with a backwashing fan blowing air into the filter body. A water retaining assembly for preventing water from flowing backwards is arranged on the backwashing air pipe between the filter tank body and the backwashing fan, the water retaining assembly comprises a water retaining pipe communicated with the backwashing air pipe, and the water retaining pipe is higher than the highest liquid level in the filter tank body. The filter tank has the effects of preventing water in the filter tank from flowing back into the backwashing fan and protecting the backwashing fan.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment, and particularly relates to a backwashing system of a biological aerated filter. BACKGROUND

[0002] The biological aerated filter (BAF) sewage treatment process belongs to the category of biological membrane method, integrates biochemical reaction and solid-liquid separation, and has been widely applied to secondary treatment and tertiary treatment in the industries of urban sewage and biodegradable industrial wastewater. The working principle of the biological aerated filter mainly includes the following two aspects: harmful substances in sewage are reduced through the oxidation and decomposition of the biological membrane attached to the filter material; the multistage filter material is subjected to the effects of layering filtration, adsorption and interception; and the nitrification and denitrification are achieved through the internal environment of the biological membrane, so that the purposes of denitrification and phosphorus removal are finally achieved. The biological aerated filter can be divided into five parts, i.e., a supporting layer, a filter material layer, a water distribution channel, a gas distribution system and a water tank. However, after the filter runs for a certain period of time, due to the strong interception effect of the filter material layer, a large amount of suspended solids in the sewage will be attached to the surface of the filter material, and the biological membrane on the surface of the filter material will also grow and thicken, which will inhibit the growth of microorganisms to a certain extent and affect the working efficiency of the filter. Therefore, the filter needs to be backwashed at intervals to remove the suspended solids intercepted in the filter material and the aged and fallen biological membrane with the backwashing water, so as to restore the normal operation of the biological filter.

[0003] The backwashing of the biological aerated filter is crucial to the normal operation of the biological aerated filter. Through the backwashing, the suspended solids intercepted on the filter material of the biological aerated filter and the excessive growth and aged microbial membrane on the filter material can be timely cleaned, so that the filter material gaps are ensured, and thus the water yield and water quality of the biological aerated filter will not be affected. At present, the standard process of the backwashing of the biological aerated filter is to reduce the liquid level of the filter, and then to sequentially perform air washing, air-water washing and water washing. In the backwashing process of the existing standard process, the liquid level is 90-100% of the height of the filter material, so that most of the filter material is in a wet or immersed state, and then the filter material is backwashed by using air washing, air-water washing and water washing. The backwashing gas pipe is connected to the biological aerated filter, one end of the backwashing gas pipe is connected to the filter, and the other end is connected to the backwashing air blower. During the backwashing process, the backwashing air blower is started, and the gas for flushing is transported to the filter through the backwashing gas pipe. This method can remove the suspended solids intercepted on the filter material of the filter to a certain extent, and clean part of the excessive growth and aged microbial membrane on the filter material.

[0004] During the backwashing process, when the backwashing air blower is closed, the pressure at the outlet end of the backwashing air blower will become smaller, and the water in the filter is prone to flow into the backwashing gas pipe, so that the water in the filter is prone to flow back to the backwashing air blower, causing damage to the backwashing air blower. CONTENT OF THE INVENTION

[0005] In order to prevent the water in the filter tank from flowing back to the backwashing air blower, the application provides a backwashing system of a biological aerated filter.

[0006] The application provides a backwashing system of a biological aerated filter, which adopts the following technical scheme:

[0007] The backwashing system of the biological aerated filter comprises a filter tank body and a backwashing air pipe connected to the filter tank body, a backwashing air blower for blowing air into the filter tank body is connected to the end of the backwashing air pipe, and a water blocking assembly for preventing water from flowing back is arranged on the backwashing air pipe between the filter tank body and the backwashing air blower, wherein the water blocking assembly comprises a water blocking pipe communicated with the backwashing air pipe, and the height of the water blocking pipe is higher than the height of the highest liquid level in the filter tank body.

[0008] By adopting the above technical scheme, during the backwashing process, when the backwashing air blower is closed, the pressure at the outlet end of the air blower will instantaneously decrease, the water in the filter tank body will flow into the backwashing air pipe due to the decrease of the outlet pressure of the backwashing air blower, the water flowing out of the filter tank body can flow upwards along the water blocking pipe by arranging the water blocking pipe on the backwashing air pipe, thereby reducing the continuous flow of the water in the filter tank body into the backwashing air pipe, and the height of the water blocking pipe is greater than the height of the liquid level in the filter tank body, so that the water in the filter tank body cannot flow to the highest point of the water blocking pipe, and the water cannot flow to the backwashing air blower.

[0009] Optionally, the water blocking pipe is in a U shape, the two ends of the water blocking pipe are connected to the backwashing air pipe, and the height of the highest point of the U-shaped bend of the water blocking pipe is at least 0.5 m higher than the liquid level in the filter tank body.

[0010] By adopting the above technical scheme, the highest point of the U-shaped bend of the water blocking pipe is at least 0.5 m higher than the liquid level in the filter tank body, so that the water in the filter tank can be prevented from flowing to the highest point of the water blocking pipe under the action of the gas pressure, and the kinetic energy of the water flowing out of the filter tank body can be greatly reduced by the height difference of at least 0.5 m between the two, so that the water cannot flow over the highest point of the water blocking pipe.

[0011] Optionally, a plurality of backwashing air blowers are arranged, and the plurality of backwashing air blowers are connected in parallel to the end of the backwashing air pipe.

[0012] By adopting the technical scheme, the multiple backwashing air fans are arranged, and different numbers of backwashing air fans can be selected and used according to the dirt degree inside the filter tank body during the washing process, the backwashing air fans can be used individually or in parallel, when the multiple backwashing air fans are used simultaneously, a large amount of gas can be delivered to the filter tank body, and the pressure of the delivered gas is increased, so that the filter material in the filter tank body is better cleaned, and the cleaning effect is improved, when the cleaning is completed and the backwashing air fans need to be stopped, the multiple air fans can be stopped one by one, so that the pressure of the air outlet of the backwashing air fan is instantaneously reduced after the air fans are stopped simultaneously, under the action of the atmospheric pressure, the water in the filter tank body flows into the backwashing air pipe quickly and passes through the water blocking pipe to flow towards the backwashing air fan, and after the backwashing air fans are stopped one by one, the pressure of the air outlet of the backwashing air fan can be gradually reduced, and the kinetic energy of the water flow into the backwashing air fan is reduced.

[0013] Optionally, the backwashing air pipe between the backwashing air fan and the water blocking assembly is communicated with a pressure balance pipe, and the pressure balance pipe is communicated with a vent valve for controlling opening and closing of the pressure balance pipe.

[0014] By adopting the technical scheme, during the backwashing process, the pressure balance pipe and the vent valve are used in cooperation, the opening or closing of the pressure balance pipe can be adjusted according to the actual situation, so that the gas pressure in the backwashing air pipe is adjusted, and the pressure concentration is avoided.

[0015] Optionally, the pressure balance pipe is communicated with an adjusting member for adjusting the pressure at a position behind the vent valve, the adjusting member comprises an adjusting box with a hollow structure, the adjusting box is communicated with the pressure balance pipe, an adjusting plate is fixedly arranged in the adjusting box, and a circular hole for adjusting the gas pressure in the pressure balance pipe is arranged in the adjusting plate.

[0016] By adopting the technical scheme, during the backwashing process, the smaller the diameter of the circular hole is, the greater the pressure of the outlet end of the backwashing air fan is, so that the phenomenon of backflow of the filter tank water is prevented.

[0017] Optionally, the diameter of the circular hole is 38mm-66mm, and the size of the diameter of the circular hole is related to the pressure of the air outlet of the fan.

[0018] By adopting the technical scheme, when the size of the diameter of the circular hole is set, the size of the diameter of the circular hole needs to be calculated according to the actual situation of the project, the water in the filter tank needs to be prevented from backflowing, and the backwashing air fan needs to be prevented from generating large noise.

[0019] Optionally, the water blocking assembly comprises a controller, an electromagnetic regulating valve connected to the pressure balance pipe, and a pressure sensor connected to the backwashing gas pipe, the pressure sensor is arranged on the backwashing gas pipe between the pressure balance pipe and the filter tank body, the controller is electrically connected with the electromagnetic regulating valve and the pressure sensor, and the pressure sensor and the electromagnetic regulating valve are cooperatively used through the controller.

[0020] By using the above technical scheme, the pressure sensor is used to detect the gas pressure in the backwashing gas pipe in real time, and the monitored gas pressure data is transmitted to the controller, and the opening and closing size of the electromagnetic regulating valve is controlled through the controller, so that automatic adjustment can be realized, and the opening size of the vent valve cannot be adjusted in time when the gas pressure in the backwashing gas pipe is too large, so that the water in the filter tank flows to the backwashing air blower. Compared with the manual adjustment mode, the automatic adjustment is faster and more accurate, a large amount of calculation is not required, and the efficiency is improved.

[0021] Optionally, the water blocking assembly comprises a water blocking piece arranged on the backwashing gas pipe, the water blocking piece comprises a connecting sleeve communicated with the backwashing gas pipe and a water blocking sleeve fixed on the connecting sleeve, the water blocking sleeve is arranged inclined to the direction of gas conveying, the water blocking sleeve is communicated with the connecting sleeve, a water blocking ball is slidingly fitted in the connecting sleeve, and a pressing spring is arranged in the connecting sleeve, one end of the pressing spring is fixed with the connecting sleeve, and the other end is fixed with the water blocking ball, and the water blocking ball is clamped and fitted in the connecting sleeve.

[0022] By using the above technical scheme, under the action of the pressing spring, the water blocking ball can be clamped and fitted in the connecting sleeve and block the pipeline of the backwashing gas pipe. In use, when the water in the filter tank body flows to the backwashing gas pipe, the water blocking ball can be clamped in the connecting sleeve under the action of the pressing spring and the extrusion of the water, so as to prevent the water in the filter tank body from continuing to move backward.

[0023] Optionally, the water blocking assembly further comprises a water blocking box connected to the backwashing gas pipe and vertically arranged, and a floating ball floatingly arranged in the water blocking box, the water blocking box has a hollow structure, the backwashing gas pipe is connected to the upper end and the lower end of the water blocking box, a tapered necking portion is arranged in the water blocking box and close to the upper end thereof, and the floating ball can be clamped and fitted to the necking portion.

[0024] By using the above technical scheme, when more water flows into the water blocking box, the floating ball can move upward, when the floating ball moves to the necking portion, the liquid surface that continues to rise can block the floating ball at the necking portion and block the backwashing gas pipe, thereby preventing the water in the filter tank from flowing to the backwashing air blower.

[0025] In summary, the present application has at least one of the following beneficial technical effects:

[0026] In the backwash process, the height of the backwash air pipe is lifted by the water blocking pipe, so that the water in the filter body can be blocked by the water blocking pipe after flowing into the backwash air pipe, thereby preventing the water in the filter body from flowing to the backwash fan; in addition, the orifice plate arranged on the pressure balance pipe can balance the air pressure in the backwash air pipe, so as to prevent the water in the filter from flowing to the backwash fan when the outlet pressure of the backwash fan becomes smaller.

[0027] By arranging the electromagnetic regulating valve on the pressure balance pipe and the pressure sensor on the backwash air pipe, the gas pressure in the backwash air pipe can be monitored in real time, and transmitted to the controller in time, and the opening and closing of the electromagnetic regulating valve can be adjusted rapidly by the controller, so that the response in the adjustment process is more rapid, and the water in the filter body is prevented from flowing to the backwash fan; and the size of the project site is not limited, and in addition, the diameter of the circular hole on the adjusting plate does not need to be calculated in detail. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a system structure schematic diagram of the embodiment one of the present application.

[0029] Figure 2 is a schematic diagram of the water blocking pipe structure of the embodiment one of the present application.

[0030] Figure 3 is a structure schematic diagram of the circular hole in the adjusting box of the embodiment one of the present application.

[0031] Figure 4 is a system structure schematic diagram of the embodiment two of the present application.

[0032] Figure 5 is a structure schematic diagram of the water blocking part of the embodiment three of the present application.

[0033] Figure 6 is a sectional view of the water blocking part of the embodiment three of the present application.

[0034] Figure 7 is a schematic diagram of the water blocking box structure of the embodiment four of the present application.

[0035] Figure 8 is a sectional view of the water blocking box structure of the embodiment four of the present application.

[0036] Explanation of reference signs: 1, filter tank body; 2, backwashing gas pipe; 3, backwashing air blower; 4, water blocking assembly; 41, water blocking pipe; 411, fixed part; 412, telescopic part; 42, electromagnetic regulating valve; 43, pressure sensor; 44, water blocking piece; 441, connecting sleeve; 442, water blocking sleeve; 443, water blocking ball; 444, abutting spring; 45, water blocking tank; 451, floating ball; 452, closing opening; 5, pressure balance pipe; 51, vent valve; 52, adjusting piece; 521, adjusting tank; 522, adjusting plate; 523, round hole. DETAILED DESCRIPTION

[0037] The following will be described in detail in combination with the accompanying drawings. Figures 1-8 The present application is further described in detail.

[0038] The present application discloses a backwashing system of a biological aerated filter.

[0039] Embodiment 1

[0040] Reference Figure 1 The backwashing system of the biological aerated filter comprises a filter tank body 1 to be backwashed, a backwashing gas pipe 2 connected to the lower end of the filter tank body 1, and a backwashing air blower 3 connected to the end of the backwashing gas pipe 2 away from the filter tank body 1. During the backwashing process of the filter tank, the backwashing air blower 3 is started to deliver gas to the inside of the filter tank body 1 through the backwashing gas pipe 2, so as to wash and clean the filter material inside the filter tank.

[0041] The backwashing air blower 3 is provided in plurality, and the plurality of backwashing air blowers 3 are connected in parallel at the end of the backwashing gas pipe 2. An air inlet valve is arranged on the pipeline connecting the backwashing air blower 3 to the backwashing gas pipe 2, and the opening or closing of the backwashing air blower 3 and the backwashing gas pipe 2 is controlled by the air inlet valve. During the backwashing process, different numbers of backwashing air blowers 3 can be selected to be started according to the dirtiness of the inside of the filter tank body 1 to be cleaned. The backwashing air blowers 3 can be operated individually or used in parallel at the same time. When the plurality of backwashing air blowers 3 are used at the same time, a large amount of gas can be delivered to the inside of the filter tank body 1, so as to increase the washing force of the filter material, and the suspended solids and biological membranes adsorbed on the filter material can be detached.

[0042] Reference Figure 1 and Figure 2A water blocking assembly 4 is arranged on the backwashing gas pipe 2 and located between the filter tank body 1 and the backwashing air blower 3, the water blocking assembly 4 comprises a water blocking pipe 41 communicated with the backwashing gas pipe 2, the water blocking pipe 41 is in U shape and vertically arranged, the two ends of the water blocking pipe 41 are downward arranged and connected with the backwashing gas pipe 2, when the water in the filter tank body 1 flows back, the water can first flow into the water blocking pipe 41 and temporarily store a certain amount of water in the water blocking pipe 41, in order to prevent the water in the filter tank body 1 from flowing back through the water blocking pipe 41, the height of the highest point of the U bend of the water blocking pipe 41 is greater than the liquid level in the filter tank body 1 by at least 0.5 m or more, the water blocking pipe 41 is arranged in communication with the inside of the filter tank body 1 and forms a communicating vessel structure, by increasing the height of the highest point of the U bend of the water blocking pipe 41, the water in the filter tank body 1 cannot impact the highest point of the water blocking pipe 41, thereby preventing the water from flowing back to the backwashing air blower 3.

[0043] The water blocking pipe 41 is composed of an arc-shaped bending section and a pair of vertical sections symmetrically arranged at the two ends of the bending section, the two vertical sections are in telescopic structure and comprise a fixed part 411 and a telescopic part 412, the telescopic part 412 is slidingly inserted and fitted on the fixed part 411, the fixed part 411 and the telescopic part 412 in sliding fit can freely adjust the height of the water blocking pipe 41, in the project site, the height of the water blocking pipe 41 can be adjusted according to the environment of the project site, by adjusting the height of the water blocking pipe 41, the water in the filter tank can be prevented from flowing to the backwashing air blower 3.

[0044] Referring to FIG. 1, a vertically arranged pressure balance pipe 5 is communicated with the backwashing gas pipe 2 between the backwashing air blower 3 and the water blocking assembly, when the gas pressure in the backwashing gas pipe 2 is relatively large, the gas can be shunted to the pressure balance pipe 5, a vent valve 51 is communicated with the pressure balance pipe 5, the vent valve 51 is used to control the opening or closing of the pressure balance pipe 5, so as to adjust the gas pressure in the backwashing gas pipe 2.

[0045] Referring to Figure 1 and Figure 3 A regulating member 52 for adjusting the gas pressure is installed on the pressure balance pipe 5 and located at a position behind the vent valve 51, the regulating member 52 comprises a hollow regulating box 521 communicated with the pressure balance pipe 5, a regulating plate 522 is fixed in the regulating box 521, a circular hole 523 for regulating the pressure is opened on the regulating plate 522, the diameter of the circular hole 523 is 38-66 mm.

[0046] The smaller the diameter of the circular hole 523 is, the greater the pressure at the outlet end of the backwashing air blower 3 will be, which can prevent the phenomenon of backflow of the filter tank water; however, when the hole diameter is too small, the pressure at the outlet end of the air blower will be increased too much, which will cause the following problems:

[0047] (1) The noise of the fan increases: a large amount of airflow noise is generated when the high-pressure gas is released through the fan outlet.

[0048] (2) The vibration of the fan increases, which may cause the wear and tear and shedding of the fan bearings, gears, impellers and other components, and the performance of the fan decreases. The airflow at the outlet of the fan becomes unstable during subsequent work, which affects the normal operation of the fan.

[0049] (3) Temperature rise: heat is generated when the high-pressure gas is released, which may cause the fan to overheat and further reduce the performance of the fan.

[0050] (4) Wind tunnel wear: the wind tunnel is severely worn, which reduces the system efficiency and causes energy waste.

[0051] (5) Damaged sealing performance: the sealing performance of the backwashing fan system is threatened, and in severe cases, the air door cannot be tightly closed and the air duct leaks.

[0052] Therefore, during the use of the backwashing fan 3, attention should be paid to the change of the outlet pressure at all times, and timely measures should be taken to ensure the normal operation of the backwashing fan 3. The hole diameter should not be blindly reduced to increase the pressure and adversely affect the backwashing fan 3.

[0053] The actual size of the hole diameter of the circular hole 523 needs to be calculated according to the actual engineering, and in the embodiment of the application, three holes with sizes of 38 mm, 53 mm and 66 mm are first tested in practice, as follows:

[0054]

[0055] Conclusion: Through the test, it can be concluded that the hole diameter of the circular hole 523 of the adjusting plate 522 should be between 38-53 mm, and new adjusting plates 522 need to be continuously produced for further testing.

[0056] Subsequent tests are conducted using new diameters, and the test results are as follows:

[0057]

[0058] Conclusion: Through the test, it can be concluded that the hole diameter of the circular hole 523 of the adjusting plate 522 is 48 mm, which can meet the requirements at the same time.

[0059] The hole diameter of the circular hole 523 calculated by the application is 38-66 mm, and finally through the test, it is found that when the hole diameter of the circular hole 523 is 48 mm, it can be used. If the hole diameter is too small, the outlet pressure of the backwashing fan 3 during venting will exceed the ideal wind pressure, which will adversely affect the backwashing fan 3. Although the best hole diameter of the hole plate can be determined through the test, this will make it difficult to determine the actual hole size during the design process, and only through the test, the final debugging process is more troublesome and complicated.

[0060] The implementation principle of embodiment 1 is that, during the flushing of the filter tank, the water in the filter tank can flow directly into the U-shaped water retaining pipe 41, and since the height of the water retaining pipe 41 is higher than the height of the water surface in the filter tank, the flow of water in the filter tank is blocked, so that the water in the filter tank cannot continue to flow to the backwashing air blower 3.

[0061] Embodiment 2

[0062] With reference to Figure 4 The difference between the present embodiment and embodiment 1 is that the water retaining assembly 4 further comprises a controller, an electromagnetic regulating valve 42 is connected to the pressure balance pipe 5, and a pressure sensor 43 is connected to the backwashing air pipe 2, the pressure sensor 43 is located between the pressure balance pipe 5 and the filter tank body 1, the pressure sensor 43 is arranged to detect the gas pressure in the backwashing air pipe 2 in real time, the electromagnetic regulating valve 42 is electrically connected to the controller, and the controller is electrically connected to the pressure sensor 43. During use, the gas pressure in the backwashing air pipe 2 is monitored in real time by the pressure sensor 43, and the monitored gas pressure data is transmitted to the controller, and the opening size of the electromagnetic regulating valve 42 is controlled by the controller, so that automatic adjustment is realized, and the opening size of the vent valve 51 cannot be adjusted in time when the gas pressure in the backwashing air pipe 2 is too large, so that the water in the filter tank flows to the backwashing air blower 3. Compared with the manual adjustment method, the automatic adjustment is faster and more accurate, and a large amount of calculation is not required, thereby improving the efficiency.

[0063] The implementation principle of embodiment 2 is that, during use, the pressure data in the backwashing air pipe 2 is monitored by the pressure sensor 43, and the monitored data is transmitted to the controller in time, and the opening size of the electromagnetic regulating valve 42 is adjusted by the controller, so that the opening of the electromagnetic regulating valve 42 can be dynamically adjusted according to the pressure data in the backwashing air pipe 2.

[0064] Embodiment 3

[0065] With reference to Figure 1 , Figure 5 and Figure 6The difference between the embodiment and the embodiment 1 is that the water blocking assembly 4 comprises a water blocking piece 44 arranged on the backwashing gas pipe 2, the water blocking piece 44 is located between the filter tank body 1 and the pressure balance pipe 5, the water blocking piece 44 comprises a connecting sleeve 441 communicated with the backwashing gas pipe 2 and a water blocking sleeve 442 fixed on the connecting sleeve 441, the water blocking sleeve 442 is obliquely fixed on the connecting sleeve 441, the lower end of the water blocking sleeve 442 is fixed on the connecting sleeve 441, the upper end is obliquely arranged towards the direction of gas conveying, the water blocking sleeve 442 is internally slidably fitted with a water blocking ball 443, the water blocking ball 443 slides along the direction of the water blocking sleeve 442, and the water blocking sleeve 442 is internally arranged with a pressing spring 444, one end of the pressing spring 444 is fixed with the water blocking ball 443, the other end is fixed with the water blocking sleeve 442, and the water blocking ball 443 can be clamped and fitted in the connecting sleeve 441 under the action of the pressing spring 444, and the pipeline of the backwashing gas pipe 2 is blocked, in the use process, if the water in the filter tank body 1 flows into the backwashing gas pipe 2, the water blocking ball 443 can be clamped in the connecting sleeve 441 under the action of the pressing spring 444 and the extrusion of water, so as to prevent the water in the filter tank body 1 from continuing to move backward, in the process of starting the backwashing fan 3 to send gas into the filter tank body 1, the water blocking ball 443 can be lifted up under the action of the gas pressure, so as to convey the gas for backwashing into the filter tank body 1.

[0066] Embodiment 4

[0067] With reference to Figure 1 , Figure 7 and Figure 8 The difference between the embodiment and the embodiment 1 is that the water blocking assembly 4 comprises a water blocking box 45 connected with the backwashing gas pipe 2 and vertically arranged, the water blocking box 45 is internally hollow, the upper and lower ends of the water blocking box 45 are connected with the backwashing gas pipe 2, the lower end of the water blocking box 45 is communicated with the filter tank body 1, the upper end of the water blocking box 45 is communicated with the backwashing fan 3, the water blocking box 45 is internally arranged with a floating ball 451, the floating ball 451 can float according to the height of the water flowing into the water blocking box 45; a tapered necking 452 is arranged at the position close to the upper end of the water blocking box 45, when the water flowing into the water blocking box 45 is more, the floating ball 451 can move upward, when the floating ball 451 moves to the position of the necking 452, the liquid surface continuing to rise can block the floating ball 451 at the necking 452, and the backwashing gas pipe 2 is blocked, so as to prevent the water in the filter tank from flowing to the backwashing fan 3, in the process of sending gas by the backwashing fan 3, the water in the water blocking box 45 can be conveyed to the filter tank body 1 first, until the water in the water blocking box 45 is completely removed, so that the gas can be conveyed to the filter tank body 1.

[0068] The above are all preferred embodiments of the present application, and do not limit the protection scope of the present application, so that: all equivalent changes made according to the structure, shape, principle of the present application should be covered in the protection scope of the present application.

Claims

1. A backwash system for a biological aerated filter, characterized by: The filter tank body (1) and the backwashing air pipe (2) connected to the filter tank body (1), the end of the backwashing air pipe (2) is connected with the backwashing fan (3) blowing air to the inside of the filter tank body (1), the water blocking assembly (4) preventing water backflow is arranged on the backwashing air pipe (2) between the filter tank body (1) and the backwashing fan (3), the water blocking assembly (4) comprises the water blocking pipe (41) communicated with the backwashing air pipe (2), and the height of the water blocking pipe (41) is higher than the height of the highest liquid level in the filter tank body (1).

2. A backwash system for a biological aerated filter according to claim 1, wherein: The water blocking pipe (41) is in U shape, the two ends of the water blocking pipe (41) are connected with the backwashing air pipe (2), and the height of the U-bend highest point of the water blocking pipe (41) is greater than the liquid level in the filter tank body (1) by at least 0.5 m.

3. The backwash system of a biological aerated filter according to claim 1, wherein: The backwashing fan (3) is provided with a plurality of parallel communication ends of the backwashing air pipe (2).

4. The backwash system of a biological aerated filter according to claim 1, wherein: The backwashing air pipe (2) between the backwashing fan (3) and the water blocking assembly (4) is communicated with the pressure balance pipe (5), the pressure balance pipe (5) is communicated with the vent valve (51) for controlling the opening and closing of the pressure balance pipe (5).

5. A backwash system for a biological aerated filter according to claim 4 wherein: The pressure balance pipe (5) is communicated with the pressure adjusting member (52) at a position behind the vent valve (51), the pressure adjusting member (52) comprises the hollow structure adjusting box (521) communicated with the pressure balance pipe (5), the adjusting plate (522) is fixedly fitted in the adjusting box (521), and the circular hole (523) for adjusting the air pressure in the pressure balance pipe (5) is formed in the adjusting plate (522).

6. A backwash system for a biological aerated filter according to claim 5 wherein: The diameter of the circular hole (523) is 38-66 mm, and the size of the circular hole (523) is related to the pressure of the fan outlet.

7. The backwash system of a biological aerated filter according to claim 1, wherein: The water blocking assembly (4) comprises a controller, an electromagnetic adjusting valve (42) connected to the pressure balance pipe (5) and a pressure sensor (43) connected to the backwashing air pipe (2), the pressure sensor (43) is arranged on the backwashing air pipe (2) between the pressure balance pipe (5) and the filter tank body (1), the controller is electrically connected with the electromagnetic adjusting valve (42) and the pressure sensor (43), and the pressure sensor (43) and the electromagnetic adjusting valve (42) are cooperatively used through the controller.

8. The backwash system of a biological aerated filter according to claim 1, wherein: The water blocking assembly (4) comprises the water blocking member (44) arranged on the backwashing air pipe (2), the water blocking member (44) comprises the connecting sleeve (441) communicated with the backwashing air pipe (2) and the water blocking sleeve (442) fixedly connected to the connecting sleeve (441), the water blocking sleeve (442) is inclinedly arranged towards the direction of gas conveying, the water blocking sleeve (442) is communicated with the connecting sleeve (441), the water blocking ball (443) is slidingly fitted in the connecting sleeve (441), the abutting spring (444) is arranged in the connecting sleeve (441), one end of the abutting spring (444) is fixedly connected with the connecting sleeve (441), the other end is fixedly connected with the water blocking ball (443), and the water blocking ball (443) is clamped and fitted in the connecting sleeve (441).

9. The backwash system of a biological aerated filter according to claim 1, wherein: The water blocking assembly (4) further comprises a water blocking tank (45) connected to the backwashing gas pipe (2) and arranged vertically, and a floating ball (451) arranged floatingly inside the water blocking tank (45), the water blocking tank (45) is a hollow structure, the backwashing gas pipe (2) is connected to the water blocking tank (45) at upper and lower end positions, a tapering necking (452) is arranged inside the water blocking tank (45) and close to the upper end position thereof, and the floating ball (451) can be clamped and fitted to the necking (452).

Images