A constant water level activated carbon filter

Abstract

This utility model discloses a constant water level activated carbon filter, relating to the field of water treatment technology. It includes an inlet structure and several filtration units, each filtration unit comprising a filtration structure and a backwashing structure. The inlet structure includes an inlet channel connected to the filtration units, with adjacent filtration units forming a water distribution zone. A partition plate within the water distribution zone divides it into an inlet water distribution zone and an outlet channel. The activated carbon filter includes a filtration state and a backwashing state. In the filtration state, the water to be filtered flows into the filtration units and the inlet water distribution zone from the inlet channel, and then flows into the filtration units. After being filtered by the filtration structure, the water flows out through the outlet channel. In the backwashing state, backwash water and backwash gas enter the filtration structure through the outlet channel, backwashing the filtration structure, and then the backwash water is discharged from the inlet water distribution zone. The backwashing of the filter media maintains a stable water level in the activated carbon filter.

Description

Technical Field

[0001] This utility model relates to the field of water treatment technology, specifically to an activated carbon filter with constant water level. Background Technology

[0002] Constant water level control in activated carbon filters essentially ensures optimal adsorption performance of activated carbon, retention capacity of the filter bed, and overall system efficiency by stabilizing hydraulic conditions. Its necessity lies not only in preventing water quality issues and equipment malfunctions, but also in extending consumable lifespan and reducing operating costs. For water plants pursuing high-quality effluent, constant water level control is not an option, but a necessity for achieving a balance between process stability and economic efficiency.

[0003] The main factors affecting water level changes in activated carbon filters are structural defects within the filter or changes in the filter media's condition, which cause water level fluctuations due to uneven resistance distribution. Specific changes include: (1) Local filter media caking or excessive growth of biofilm on activated carbon causes filter media layer blockage. The resistance in the blocked area increases sharply, and water flow concentrates in the area with low resistance, forming channel flow, resulting in local water level being low and overall water level being high due to the increase in total resistance. (2) The filter media settles unevenly after backwashing, resulting in sand dunes or depressions, which causes uneven distribution of filter media. The resistance is high in the high filter media area and low in the low filter media area, resulting in unbalanced water flow distribution and periodic fluctuations in water level as the water flow path changes. Utility Model Content

[0004] This invention aims to address one of the technical problems in related technologies to a certain extent. To this end, this invention provides a constant-water-level activated carbon filter, which maintains a stable water level in the activated carbon filter by backwashing the filter media.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A constant water level activated carbon filter includes an inlet structure and several filtration units, each filtration unit including a filtration structure and a backwashing structure. The water inlet structure includes a water inlet channel, and the filter units are arranged along the length of the water inlet channel. The water inlet channel is connected to the filter units above the filter structure. A water distribution area is formed between adjacent filter units. A partition plate is provided in the water distribution area, and the partition plate divides the water distribution area from top to bottom into a water inlet distribution area and a water outlet channel. The water inlet distribution area is connected to the filter units above the filter structure, and the water outlet channel is connected to the filter units below the filter structure. The activated carbon filter includes a filtration state and a backwashing state. In the filtration state, the water to be filtered enters through the inlet channel and flows into the filtration unit and the inlet water distribution area. The water to be filtered in the inlet water distribution area flows into the filtration unit. In the filtration unit, the water to be filtered passes through the filtration structure and then flows out through the outlet channel. In the backwashing state, backwash water and backwash gas enter the filtration structure through the outlet channel. After backwashing the filtration structure, the backwash water is discharged from the inlet water distribution area.

[0006] Backwashing refers to the process of flushing the filter media in an activated carbon filter in a direction opposite to the flow of water during filtration. This invention suppresses factors that make it difficult to maintain a constant water level through the backwashing process. In existing technologies, activated carbon filters, due to the lack of backwashing or incomplete backwashing, are prone to localized filter media caking or blockage caused by excessive biofilm growth on the activated carbon. This significantly increases filtration resistance, leading to a surge in head loss. To maintain flow, the influent water level must be raised, resulting in water level control failure. Simultaneously, the uneven settling of filter media after backwashing, forming sand dunes or depressions, leads to extremely uneven distribution of the water flow cross-section, causing flow deviation and further disrupting water level stability. This invention, however, establishes a dedicated channel (inlet through the outlet channel, outlet through the inlet distribution area) for the backwash air-water mixture and wastewater, completely opposite to and isolated from the filtration path. This ensures that the backwashing energy is evenly and fully applied to the entire filter media layer and guarantees smooth discharge of the backwash air-water mixture and wastewater. This reverse flushing can break down and remove clumps and excessively thick biofilm, restoring the permeability of the filter media. At the same time, the intense and uniform scrubbing action can cause the filter media to settle evenly again after backwashing, effectively preventing the formation of sand dunes or depressions. This eliminates the two factors that cause water level fluctuations: filter media clogging and uneven distribution, thus enabling the activated carbon filter to maintain a constant water level during operation.

[0007] Optionally, the backwashing structure includes a backwashing air pipe for backwashing gas to enter, a backwashing water inlet pipe for backwashing water to enter, and a backwashing drain pipe for backwashing water to exit. The backwashing air pipe and the backwashing water inlet pipe are connected to the water outlet channel. The water outlet channel is provided with air holes for backwashing gas to enter the filter unit. The backwashing drain pipe is connected to the water inlet distribution area.

[0008] Optionally, the partition plate is inclined in the vertical direction, the backwash water inlet pipe and the backwash air pipe are on the higher side of the partition plate, and the backwash water inlet pipe is located below the backwash air pipe, while the backwash drain pipe is on the lower side of the partition plate.

[0009] Optionally, the water inlet structure further includes water distribution channels, which are provided in multiple ways in each filtration unit and are all located above the filtration structure. The water to be filtered in the water inlet distribution area flows into the filtration unit through the water distribution channels.

[0010] Optionally, the inlet channel is provided with a weir plate, which divides the inlet channel into an inlet channel and a rectifier zone along the length of the inlet channel, and the rectifier zone is connected to the filter unit.

[0011] Optionally, the water inlet structure further includes an overflow channel, the length direction of which is parallel to the length direction of the water inlet channel. The overflow channel and the rectifier zone are located on opposite sides of the water inlet channel, and the water inlet channel and the overflow channel are connected by a first overflow pipe.

[0012] Optionally, the water inlet structure further includes a second overflow pipe and an overflow drain pipe, wherein the second overflow pipe is located at the end of the overflow channel, and the overflow channel is connected to the overflow drain pipe through the second overflow pipe.

[0013] Optionally, the activated carbon filter also includes an equalization tank, with the water outlet channels on both sides of the same filtration unit sharing a common equalization tank, and each water outlet channel communicating with only one equalization tank.

[0014] Optionally, the filter structure includes, from top to bottom, an activated carbon layer, a quartz sand layer, a support layer, and a filter head plate.

[0015] Optionally, the inlet channel is equipped with a flow meter, and each of the filter units is equipped with a level gauge.

[0016] These features and advantages of this utility model will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of this utility model will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of this utility model. In addition, each of these features, elements and components appearing in the following text and drawings is multiple and is labeled with different symbols or numbers for convenience, but all represent parts with the same or similar structure or function. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings: Figure 1 This is a top view of an embodiment of the present utility model; Figure 2 This is a cross-sectional schematic diagram of the filtration unit and water distribution area in an embodiment of this utility model; Figure 3 This is a cross-sectional schematic diagram of the water inlet structure and the filter unit in an embodiment of this utility model; Figure 4This is a cross-sectional schematic diagram of the filter unit and backwashing structure in an embodiment of the present invention.

[0018] in: 1-Inlet pipe, 10-Ozone contact tank, 11-Inlet channel, 111-Weir plate, 112-Rectifying plate, 113-Inlet channel, 114-Rectifying zone, 12-Water distribution zone, 121-First water distribution baffle, 122-Second water distribution baffle, 123-Inlet pipe of water distribution zone, 124-Inlet valve of water distribution zone, 125-Divider plate, 13-Water distribution channel, 14-Overflow channel, 141-First overflow pipe, 142-Overflow valve, 143-Second overflow pipe, 144-Overflow pipe, 145-Vent pipe; 2-Filter unit, 21-Activated carbon layer, 22-Quartz sand layer, 23-Support layer, 24-Filter head plate; 31-Outlet pipe, 32-Outlet valve, 33-Regulating tank, 34-Main outlet pipe, 35-Outlet; 41-Backwash air pipe, 411-Air hole, 42-Backwash water inlet pipe, 43-Backwash water inlet valve, 44-Backwash drain pipe, 45-Backwash drain valve; 5-Flow meter, 6-Level gauge, 7-Maintenance access channel Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain this utility model and should not be construed as limiting it.

[0020] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this patent. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0021] Example: like Figure 1 As shown, this embodiment provides a constant water level activated carbon filter, including an inlet structure, an equalization tank 33 and several filtration units 2, each filtration unit 2 including a filtration structure and a backwashing structure; The water inlet structure includes an inlet channel 11, a distribution channel 13, a vent pipe 145, an overflow channel 14, a second overflow pipe 143, and a discharge pipe 144. A flow meter 5 is installed at the inlet of the inlet channel 11 to detect the inlet flow rate. Filter units 2 are arranged along the length of the inlet channel 11. A weir plate 111 is installed within the inlet channel 11, dividing it into an inlet channel 113 and a rectifying zone 114. The rectifying zone 114 is separated from the filter units 2 by a rectifying plate 112. The rectifying plate 112 has rectifying holes (not shown in the figure), allowing the rectifying zone 114 to communicate with the filter units 2 above the filter structure. This achieves precise control of the inlet flow rate and flow pattern. The weir plate 111 stabilizes the influent water level, serving as a preliminary buffer and distribution mechanism. The subsequent rectifying zone 114 effectively smooths and regulates the water flow, eliminating turbulence and impact loads from the preceding processes, ensuring a stable and uniform flow into each filtration unit 2. This structure guarantees the uniformity of water distribution, a crucial prerequisite for the activated carbon filter to achieve stable operation at a constant water level and high-efficiency filtration.

[0022] The overflow channel 14 is parallel to the length of the inlet channel 11. The overflow channel 14 and the rectifying zone 114 are located on opposite sides of the inlet channel 113, respectively. The inlet channel 113 and the overflow channel 14 are connected by a first overflow pipe 141, which is equipped with an overflow valve 142. A vent pipe 145 and a second overflow pipe 143 are located at the ends of the overflow channel 14, and an overflow discharge pipe 144 is located below the overflow channel 14. The overflow channel 14 is connected to the overflow discharge pipe 144 via the vent pipe 145 and the second overflow pipe 143. When the inlet flow rate instantaneously exceeds the design load or a blockage occurs, the excess water can be safely and properly discharged through the overflow system in an orderly manner, thereby avoiding the risk of uncontrolled water level rise or even flooding and water leakage inside the activated carbon filter, and ensuring the stability and safety of the entire water plant process.

[0023] like Figure 2 As shown, the filter structure, from top to bottom, includes an activated carbon layer 21, a quartz sand layer, a support layer 23, and a filter head plate 24. Each filter unit 2 is equipped with a level gauge 6. In this embodiment, the level gauge 6 is preferably an ultrasonic level gauge 6. Furthermore, each filter unit 2 is equipped with a maintenance channel 7.

[0024] like Figure 1 and Figure 3As shown, a water distribution area 12 is formed between adjacent filter units 2. The water distribution area 12 is separated from the filter unit 2 by a first water distribution baffle 121 and from the rectifier area 114 by a second water distribution baffle 122. The rectifier baffle 112 and the second water distribution baffle 122 can be integrally formed or spliced ​​together; no limitation is made here. A water distribution area inlet pipe 123 is provided on the second water distribution baffle 122, and a water distribution area inlet valve 124 is provided on the water distribution area inlet pipe 123. A partition plate 125 is provided inside the water distribution area 12. The partition plate 125 is inclined in the vertical direction, dividing the water distribution area 12 from top to bottom into an inlet water distribution area and an outlet water channel. The inlet water distribution area is above the filter structure and communicates with the filter unit 2. Specifically, a water distribution port is provided above the first water distribution baffle 121, and multiple water distribution channels 13 are provided in each filter unit 2, all located above the filter structure. The number of water distribution ports on a single first water distribution baffle 121 is the same as the number of water distribution channels 13 in a single filter unit 2, thus the water distribution ports and water distribution channels 13 correspond one-to-one and are connected. The water to be filtered in the inlet water distribution area flows into the filter unit 2 through the water distribution channels 13. The water distribution channels 13 further distribute the water flow from the inlet water distribution area. This multi-point, uniform water distribution method can effectively eliminate water flow dead zones, ensuring that the water to be filtered covers the entire filter cross-section with almost the same flow rate and pressure, thereby greatly improving the utilization rate of the filter media structure and preventing the occurrence of local filtration overload. The water outlet channel is connected to the filter unit 2 below the filter structure. Specifically, a water outlet 35 is provided below the first baffle 125.

[0025] The water outlet channels on both sides of the same filter unit 2 share a common regulating tank 33. The regulating tank 33 is connected to the water outlet channel via a water outlet pipe 31, which is equipped with a water outlet valve 32. Each water outlet channel is connected to only one regulating tank 33, resulting in an empty area approximately the size of one filter unit 2 between adjacent regulating tanks 33. Several regulating tanks 33 are connected to the main water outlet pipe 34. The regulating tank 33 can balance the water volume and pressure of the outlet, playing a role in buffering the water flow and "equalizing pressure and flow," preventing backflow caused by excessive water flow, ensuring the synchronicity and stability of the operation of each filter unit 2, and further consolidating the realization of constant water level filtration.

[0026] like Figure 4As shown, the backwashing structure includes a backwashing air pipe 41 for backwashing gas, a backwashing water inlet pipe 42 for backwashing water, and a backwashing drain pipe 44 for backwashing water discharge. In this embodiment, the backwashing water inlet pipe 42 shares a portion of the pipeline with the outlet pipe 31. Specifically, the backwashing water inlet pipe 42 is equipped with a backwashing water inlet valve 43. One end of the outlet pipe 31 is connected to the regulating tank 33, and the other end is connected to the backwashing water inlet pipe 42 between the outlet channel and the backwashing water inlet valve 43. The backwashing air pipe 41 and the backwashing water inlet pipe 42 are connected to the outlet channel on the higher side of the partition plate 125, and the backwashing water inlet pipe 42 is located below the backwashing air pipe 41. The outlet channel is provided with an air hole 411 for backwashing gas to enter the filter unit 2. The backwashing drain pipe 44 is located on the second water distribution partition plate 122, connected to the water distribution area, and located on the lower side of the partition plate 125. In this embodiment, the backwash drain pipe 44 and the overflow pipe 144 share the same pipeline. In other embodiments, the overflow pipe 144 and the backwash drain pipe 44 may also be divided into different pipelines.

[0027] The activated carbon filter includes a filtration state and a backwashing state. In the filtration state, the backwash inlet valve 43 and the backwash outlet valve 45 are closed, while the outlet valve 32 and the distribution zone inlet valve 124 are open. The water to be filtered enters the ozone contact tank 10 through the inlet pipe 1. The ozone contact tank 10 is existing technology and will not be described in detail here. After passing through the ozone contact tank 10, the water enters the inlet channel 11, specifically the inlet channel 113 of the inlet channel 11. The water to be filtered overflows from the weir plate 111 in the inlet channel 113 and enters the rectifier zone 114, flowing into the filter unit 2 through the rectifier holes on the rectifier plate 112. At the same time, the distribution zone inlet valve 124 is opened, and the water to be filtered enters the inlet distribution zone through the distribution zone inlet pipe 123. The water to be filtered in the inlet distribution zone enters the distribution channel 13 through the distribution port and overflows from the distribution channel 13 into the filter unit 2. The water to be filtered is guided by the rectifier zone 114 and the inlet water distribution zone, and enters the filter unit 2 evenly and stably through the rectifier holes and the inlet channel 11, and is distributed to the upper layer of the filter structure. Inside the filter unit 2, the water to be filtered is filtered by the filter structure to form clean water. The clean water enters the outlet channel through the outlet 35, and then enters the outlet pipe 31 through the backwash inlet pipe 42 at the front end of the backwash inlet valve 43. Then, it enters the regulating tank 33 for buffering through the outlet pipe 31, and then flows out through the main outlet pipe 34.

[0028] Backwashing refers to the process of flushing the filter media in an activated carbon filter, where the flow direction of water and / or air is opposite to the flow direction of water during water filtration. In backwashing mode, the outlet valve 32 and the water distribution zone inlet valve 124 are closed, while the backwash inlet valve 43 and the backwash outlet valve 32 are open. Figure 4As shown, following the direction of the arrow, backwash water enters the outlet channel through the backwash inlet pipe 42, and then enters the filter structure through the outlet 35 to perform water flushing on the filter structure. Backwash gas enters the outlet channel through the backwash air inlet pipe, and then enters the filter structure through the air hole 411 to form an air cushion layer on the filter structure. Subsequently, the backwash gas performs air washing on the filter structure, flushing away impurities on the filter media. After backwashing the filter structure, the backwash gas is directly discharged into the atmosphere through the open filter unit 2, while the backwash water and impurities enter the inlet water distribution area through the water distribution channel 13. Because the partition plate 125 is inclined in the vertical direction and the backwash drain pipe 44 is located on the lower side of the partition plate 125, the backwash water and impurities in the inlet water distribution area are completely discharged under the action of gravity.

[0029] The technical solution provided in this embodiment suppresses factors that make it difficult to maintain a constant water level during the backwashing process. In the prior art, activated carbon filters, due to the lack of backwashing or incomplete backwashing, are prone to local filter media caking or blockage caused by excessive growth of biofilm on the activated carbon. This significantly increases filtration resistance, leading to a surge in head loss. To maintain the flow rate, the influent water level must be raised, causing water level control failure. At the same time, sand dunes or depressions formed by inconsistent sedimentation of the filter media after backwashing can lead to extremely uneven distribution of the water flow cross-section, resulting in flow deviation, which also disrupts the stability of the water level. In contrast, this embodiment establishes a dedicated channel (inlet in the outlet channel, outlet in the inlet distribution area) for the backwash air-water mixture and wastewater, which is completely opposite to and isolated from the filtration path. This ensures that the backwashing energy can be applied evenly and fully to the entire filter media layer, and also ensures smooth discharge of the backwash air-water mixture and wastewater. This reverse flushing can break down and remove clumps and excessively thick biofilm, restoring the permeability of the filter media. At the same time, the intense and uniform scrubbing action can cause the filter media to settle evenly again after backwashing, effectively preventing the formation of sand dunes or depressions. This eliminates the two factors that cause water level fluctuations: filter media clogging and uneven distribution, thus enabling the activated carbon filter to maintain a constant water level during operation.

[0030] The above are merely specific embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Those skilled in the art should understand that this utility model includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of this utility model will be included within the scope of the claims.

Claims

1. A constant water level activated carbon filter, characterized in that, The activated carbon filter includes an inlet structure and several filtration units, each filtration unit including a filtration structure and a backwashing structure. The water inlet structure includes a water inlet channel, and the filter units are arranged along the length of the water inlet channel. The water inlet channel is connected to the filter units above the filter structure. A water distribution area is formed between adjacent filter units. A partition plate is provided in the water distribution area, and the partition plate divides the water distribution area from top to bottom into a water inlet distribution area and a water outlet channel. The water inlet distribution area is connected to the filter units above the filter structure, and the water outlet channel is connected to the filter units below the filter structure. The activated carbon filter includes a filtration state and a backwashing state. In the filtration state, the water to be filtered enters through the inlet channel and flows into the filtration unit and the inlet water distribution area. The water to be filtered in the inlet water distribution area flows into the filtration unit. In the filtration unit, the water to be filtered is filtered by the filtration structure and then flows out through the outlet channel. In the backwashing state, backwash water and backwash gas enter the filter structure through the water outlet channel, and after backwashing the filter structure, the backwash water is discharged from the water inlet distribution area.

2. The activated carbon filter with constant water level according to claim 1, characterized in that, The backwashing structure includes a backwashing air pipe for backwashing gas to enter, a backwashing water inlet pipe for backwashing water to enter, and a backwashing drain pipe for backwashing water to exit. The backwashing air pipe and the backwashing water inlet pipe are connected to the water outlet channel. The water outlet channel is provided with air holes for backwashing gas to enter the filter unit. The backwashing drain pipe is connected to the water inlet distribution area.

3. The activated carbon filter with constant water level according to claim 2, characterized in that, The partition plate is inclined vertically, the backwash water inlet pipe and the backwash air pipe are on the higher side of the partition plate, and the backwash water inlet pipe is located below the backwash air pipe, while the backwash drain pipe is on the lower side of the partition plate.

4. The activated carbon filter with constant water level according to any one of claims 1 to 3, characterized in that, The water inlet structure also includes water distribution channels, which are provided in multiple ways in each filtration unit and are all located above the filtration structure. The water to be filtered in the water inlet distribution area flows into the filtration unit through the water distribution channels.

5. The activated carbon filter with constant water level according to any one of claims 1 to 3, characterized in that, The inlet channel is equipped with a weir plate, which divides the inlet channel into an inlet channel and a rectifier zone along the length of the inlet channel. The rectifier zone is connected to the filter unit.

6. The activated carbon filter with constant water level according to claim 5, characterized in that, The water inlet structure also includes an overflow channel, the length of which is parallel to the length of the water inlet channel. The overflow channel and the rectifier zone are located on opposite sides of the water inlet channel, and the water inlet channel and the overflow channel are connected by a first overflow pipe.

7. The activated carbon filter with constant water level according to claim 6, characterized in that, The water inlet structure also includes a second overflow pipe and an overflow drain pipe. The second overflow pipe is located at the end of the overflow channel, and the overflow channel is connected to the overflow drain pipe through the second overflow pipe.

8. The activated carbon filter with constant water level according to any one of claims 1 to 3, characterized in that, The activated carbon filter also includes an equalization tank. The water outlet channels on both sides of the same filtration unit share an equalization tank, and each water outlet channel is connected to only one equalization tank.

9. The activated carbon filter with constant water level according to any one of claims 1 to 3, characterized in that, The filter structure, from top to bottom, includes an activated carbon layer, a quartz sand layer, a support layer, and a filter head plate.

10. The activated carbon filter with constant water level according to any one of claims 1 to 3, characterized in that, The water inlet channel is equipped with a flow meter, and each of the filter units is equipped with a level gauge.

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