Multi-effect anti-caking and oxygen-removing integrated device and application method thereof

Abstract

The application discloses a multi-effect anti-caking oxygen-removing filtration integrated device and an application method thereof, and belongs to the field of water treatment of compressed air energy storage systems. The device comprises a tank body, a composite filter layer and a backwashing system. The upper portion of the tank body is provided with a water inlet, the lower portion is provided with a water outlet, the bottom is provided with a water distribution system, and the top is provided with a backwashing water outlet. The composite filter layer is filled in the tank body and comprises a quartz sand filter layer and a sponge iron oxygen-removing layer from top to bottom, and the quartz sand filter layer and the sponge iron oxygen-removing layer are in direct contact. The backwashing system is connected with the water distribution system and is used for introducing backwashing water into the water distribution system to integrally backwash the composite filter layer. The water distribution system is arranged at the lower portion of the composite filter layer. The application method comprises a water production operation step and a backwashing step. The application highly integrates the filtration and oxygen-removing functions, realizes the synergistic effect of oxygen removal and filtration, solves the technical problem of filter material caking caused by suspended solids, and reduces the system investment and operation and maintenance costs.

Description

Technical Field

[0001] This invention relates to the fields of compressed air energy storage systems and industrial water treatment technology, and in particular to a multi-effect anti-caking deoxygenation filtration integrated device and its application method. Background Technology

[0002] In compressed air energy storage (CAES) systems, water is a commonly used medium for heat storage and exchange, and its quality directly affects the system's operating efficiency and equipment lifespan. During the system's heat storage / release cycle, the quality of the makeup water and circulating medium is subject to extremely high requirements, with dissolved oxygen and suspended solids being two key control indicators. Dissolved oxygen can trigger electrochemical corrosion, severely damaging storage tanks, pipelines, and heat exchange equipment; while suspended solids can lead to internal scaling and filter media caking, increasing operating resistance and reducing overall energy efficiency.

[0003] Currently, the conventional treatment process for the aforementioned water quality issues mainly adopts a split-type treatment mode of "multiple devices in series". The specific implementation scheme is usually a combination of "multi-media filter + deaerator (such as vacuum degassing tower or sponge iron deaerator)". This scheme removes suspended solids from the water through the front-end filter and then reduces the dissolved oxygen content through the back-end deaerator in order to meet the makeup water standard of the closed-loop heat exchange system.

[0004] The aforementioned traditional split-processing solution has the following inherent drawbacks in practical applications:

[0005] (1) The system is complex and costly: the large number of equipment, the large area occupied, and the complex connection pipelines result in high initial investment, operation and maintenance costs.

[0006] (2) Poor synergy and risk of secondary pollution: The upstream and downstream equipment operate independently and lack a synergistic mechanism. If the upstream filter is ineffective, high concentrations of suspended solids will enter the downstream deoxygenation equipment. Especially for commonly used sponge iron deoxygenation filter media, excessive suspended solids in the influent are the main cause of its rapid caking and failure. If a precision filter is added after the deoxygenation equipment to intercept the generated iron filings, new oxygen may be introduced due to poor sealing, causing secondary pollution.

[0007] (3) Chemical consumption and impurity accumulation: Chemical deoxygenation (such as adding sodium sulfite or hydrazine) introduces new ions into the system, and the dosage is large. Under closed system conditions with no sewage discharge, impurities are easily accumulated, posing an operational risk.

[0008] (4) Insufficient adaptability to operating conditions: Traditional split-type systems are difficult to adapt to fluctuations in raw water quality (especially suspended solids concentration) and have poor compatibility with the intermittent and variable operating characteristics unique to compressed air energy storage systems.

[0009] (5) Heat source limitation: Compressed air energy storage projects usually do not have a steam source, which leads to conventional heat source limitation.

[0010] Deoxygenation methods are difficult to implement. Summary of the Invention

[0011] The technical problem this invention aims to solve is to provide a multi-effect anti-caking deoxygenation filtration integrated device and its application method, which aims to address the problems of equipment redundancy, poor coordination, easy caking and failure of deoxygenation filter media, and insufficient adaptability to heat source-free operating conditions in existing split-type water treatment systems. Through physical structural innovation, the filtration and deoxygenation functions are highly integrated, solving the technical bottleneck of filter media caking caused by suspended solids; through a unique internal structure and operating logic, synergistic effects of deoxygenation and filtration are achieved, thereby reducing system investment and maintenance costs, adapting to fluctuations in raw water quality, and meeting the demand for high-quality water replenishment in heat source-free scenarios such as compressed air energy storage.

[0012] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0013] A multi-effect anti-caking deoxygenation filtration integrated device includes: a tank, a composite filter layer, and a backwashing system; the tank has an inlet at the top, an outlet at the bottom, a water distribution system at the bottom, and a backwash drain at the top; the composite filter layer is filled in the tank, consisting of a quartz sand filter layer and a sponge iron deoxygenation layer from top to bottom, with the quartz sand filter layer and the sponge iron deoxygenation layer in direct contact; the backwashing system is connected to the water distribution system and is used to introduce backwash water into the water distribution system to perform integrated backwashing of the composite filter layer; the water distribution system is located at the bottom of the composite filter layer.

[0014] A further improvement of the technical solution of the present invention is that the tank body is made of carbon steel lined with rubber.

[0015] A further improvement of the technical solution of the present invention is that the density of the quartz sand filter material used in the quartz sand filter layer is lower than that of the sponge iron filter material used in the sponge iron deoxygenation layer, and the particle size of the quartz sand filter material is smaller than that of the sponge iron filter material.

[0016] A further improvement of the technical solution of the present invention is that: the backwashing system includes a backwash water pump, a backwash water inlet pipe and a control system; the backwash water inlet pipe is equipped with a manual backwash water isolation valve and an automatic backwash water inlet valve.

[0017] A further improvement of the technical solution of the present invention is that the control system includes a differential pressure sensor, which is used to detect the pressure difference between the inlet and the outlet, and triggers the backwashing system to start when the pressure difference reaches a set threshold.

[0018] A further improvement of the technical solution of the present invention is that the control system further includes an effluent water quality monitoring instrument, which includes a turbidity meter and a dissolved oxygen meter, used to monitor the effluent water quality to assist in determining the timing of backwashing.

[0019] A further improvement of the technical solution of the present invention is that the backwash water flow direction of the backwash system is opposite to that of the product water flow direction. After the backwash water flows through the sponge iron deoxygenation layer and the quartz sand filter layer in sequence, it is discharged from the backwash drain outlet.

[0020] A further improvement of the technical solution of the present invention is that the device satisfies the filter media synergy index (SFI) being greater than 0.7, wherein the SFI is defined as follows:

[0021]

[0022] In the formula: The pressure differential increment of the composite filter layer containing the quartz sand filter layer during the standard test cycle; The pressure difference increment of a pure sponge deoxygenation layer without a quartz sand filter layer under the same test conditions; This refers to the dissolved oxygen concentration in the influent. This refers to the dissolved oxygen concentration in the effluent.

[0023] A further improvement of the technical solution of the present invention is that: the front end of the water inlet is provided with a manual water isolation valve and an automatic water inlet valve, and the rear end of the water outlet is provided with an automatic water production valve.

[0024] A method for applying a multi-effect anti-caking, deoxygenating, and filtration integrated device includes the following steps:

[0025] Water production operation steps: Open the automatic water inlet valve at the front of the inlet and the automatic water production valve at the rear of the outlet to allow the incoming water to enter the tank. First, the water passes through the quartz sand filter layer to remove suspended solids, then through the sponge iron deoxygenation layer to remove dissolved oxygen, and finally it is discharged from the outlet.

[0026] Backwashing steps: When the pressure difference between the inlet and outlet water of the tank reaches the set threshold or the operation reaches the set time, close the automatic water inlet valve and the automatic water production valve, and turn on the backwashing system to allow backwash water to enter from the bottom water distribution system and flow from bottom to top through the sponge iron deoxygenation layer and the quartz sand filter layer to clean the composite filter layer in one go. The cleaning wastewater is discharged from the top backwash drain outlet. After the backwashing is completed, the water production operation is restored.

[0027] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:

[0028] 1. This invention integrates filtration and deoxygenation functions into a single tank, eliminating the need for a separate series process of "multi-media filter + deaerator". This significantly reduces the number of devices, floor space, and connecting pipelines, thereby lowering the initial investment and operation and maintenance costs of the system.

[0029] 2. This invention achieves functional synergy through a unique layered structure design of "quartz sand on top and sponge iron on the bottom": the upper layer of quartz sand pre-intercepts suspended solids in the influent, effectively protecting the lower layer of sponge iron deoxygenation layer from pollution, fundamentally solving the problem of caking failure caused by the intrusion of suspended solids in traditional sponge iron deoxygenation filter media, and significantly extending the service life of the filter media.

[0030] 3. This invention addresses the differences in density and particle size between quartz sand and sponge iron filter media by using precise fluid calculations to determine the compatibility backwash intensity. This enables efficient cleaning of both filter media in a single backwash, avoiding the complex operation of layered backwashing and ensuring long-term stable operation of the device.

[0031] 4. This invention is equipped with a differential pressure sensor and an effluent water quality monitor. The control system intelligently judges the timing of backwashing based on the increase of the total differential pressure of the composite filter layer and the change of effluent water quality, realizing the automated operation and precise maintenance of the device and reducing the need for manual intervention.

[0032] 5. This invention uses mature filtration and deoxygenation materials, resulting in lower equipment and operating costs; it is suitable for various working conditions such as large fluctuations in raw water quality and the absence of heat sources (such as compressed air energy storage systems), and has good adaptability and economy.

[0033] 6. This invention introduces the "Synergy Index of Filter Media (SFI)" as a comprehensive evaluation index, which can quantitatively evaluate the protective effect of the quartz sand pre-filtration layer on the sponge iron deoxygenation layer and the overall deoxygenation efficiency, providing a scientific basis for the optimized design and operation control of the device. The SFI value of the preferred implementation scheme is greater than 0.7, which reflects a significant technical synergy effect. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a multi-effect anti-caking, deoxygenation, and filtration integrated device provided in an embodiment of the present invention;

[0036] Figure 2This is a schematic diagram of the structure of the quartz sand filter layer and the sponge iron deoxygenation layer inside the tank in an embodiment of the present invention;

[0037] The components include: A. Quartz sand filter layer; B. Sponge iron deoxygenation layer; 1. Tank body; 2. Inlet water pipe; 2-1. Inlet water manual isolation valve; 2-2. Inlet water automatic inlet valve; 2-3. First pressure gauge; 3. Product water pipe; 3-1. Automatic product water valve; 3-2. Second pressure gauge; 4. Forward wash drainage pipe; 5. Backwash water inlet pipe; 5-1. Backwash water manual isolation valve; 5-2. Backwash water automatic inlet valve; 6. Backwash water drainage pipe; 7. Exhaust pipe; 8. Vent pipe; 9. Differential pressure sensor; 10. Drainage tank; 11. Flow meter; 12. Dosing pipe; 12-1. Check valve; 12-2. Shut-off valve; 13. Pipeline mixer. Detailed Implementation

[0038] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0039] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0042] like Figure 1 , Figure 2 As shown, a multi-effect anti-caking and deoxygenation filtration integrated device includes: a tank 1, a composite filter layer, and a backwashing system;

[0043] The upper part of the tank body 1 is provided with an inlet for connecting to the water supply pipe 2, and the lower part is provided with an outlet for connecting to the water production pipe 3; the water supply pipe 2 is located above the composite filter layer inside the tank body 1, and the water production pipe 3 is located below the composite filter layer.

[0044] The composite filter layer is filled in the tank 1, and from top to bottom it consists of a quartz sand filter layer A and a sponge iron deoxygenation layer B, and the quartz sand filter layer A and the sponge iron deoxygenation layer B are in direct contact.

[0045] The tank body 1 is equipped with only a composite filter layer and a water distribution system arranged at the lower end of the composite filter layer (not shown in the figure); the lower part of the tank body 1 is also equipped with a water distribution port (or structure) that is integrated with the water distribution system, and the top is equipped with a backwash drain port that is connected to the backwash water drain pipe 6.

[0046] In addition, a forward wash drain pipe 4 is installed on the lower outer side of tank 1 to discharge the cleaning water used during the forward rinsing of the composite filter layer. A vent pipe 8 is connected to the forward wash drain pipe 4, through which water discharged during forward washing and venting flows into the drainage pool 10. An exhaust pipe 7 is also installed on the top of tank 1 to discharge accumulated gases during operation. Condensate generated in the exhaust pipe 7 flows into the drainage pool 10. Automatic control valves (all connected to the control system) are installed on the backwash water drain pipe 6, exhaust pipe 7, and vent pipe 8 for automatic control of the program.

[0047] The backwashing system is connected to the water distribution system and is used to introduce backwash water into the water distribution system. After the backwash water is evenly distributed through the water distribution system, the composite filter layer is backwashed in an integrated manner.

[0048] Furthermore, tank 1 is made of carbon steel lined with rubber. Specifically, it uses carbon steel as the base material and is lined with an anti-corrosion rubber layer. This utilizes the high strength of carbon steel to ensure that it serves as the pressure-bearing main body of the device and can stably withstand the internal pressure during operation. At the same time, the rubber lining effectively isolates water corrosion, significantly extending the service life of the equipment.

[0049] Furthermore, such as Figure 2 As shown, quartz sand filter layer A is located at the top of the composite filter layer, and sponge iron deoxygenation layer B is located at the bottom. The density of the quartz sand filter media used in quartz sand filter layer A is lower than that of the sponge iron filter media used in sponge iron deoxygenation layer B, and the particle size of the quartz sand filter media is smaller than that of the sponge iron filter media. Utilizing the gradient difference in density and particle size, the two filter media can be effectively separated during backwashing, avoiding filter layer mixing and caking. During normal filtration, the incoming water first flows through quartz sand filter layer A, using its interception function to remove suspended solids in the water, and then enters sponge iron deoxygenation layer B, where the redox reaction of the sponge iron efficiently removes dissolved oxygen from the water, thus achieving integrated and synergistic treatment of filtration and deoxygenation.

[0050] Furthermore, the backwashing system includes a backwash water pump (one unit), a backwash inlet pipe 5, and a control system. The control system monitors the pressure difference between the inlet and outlet water of tank 1 in real time; when the pressure difference reaches a set threshold, the backwashing program is automatically initiated. An automatic backwash water inlet valve 5-2 and a manual backwash water isolation valve 5-1 are sequentially installed on the backwash inlet pipe 5, used for automatic program control and pipeline maintenance isolation, respectively.

[0051] Furthermore, the control system includes a differential pressure sensor 9, which is connected via pipelines to a first pressure gauge 2-3 and a second pressure gauge 3-2 to detect the pressure difference between the inlet and outlet in real time. The first pressure gauge 2-3 is installed on the incoming water pipeline 2 to monitor the inlet pressure; the second pressure gauge 3-2 is installed on the product water pipeline 3 to monitor the outlet pressure. Instrument valves are installed on the connecting pipelines between the differential pressure sensor 9 and the two pressure gauges for pipeline on / off control and maintenance isolation. When the pressure difference reaches a set threshold, the control system automatically triggers the backwashing program.

[0052] Furthermore, the control system is also equipped with effluent water quality monitoring instruments, specifically including a turbidity meter and a dissolved oxygen meter. Both the turbidity meter and the dissolved oxygen meter are installed on the product water pipeline 3 for real-time monitoring of the effluent water quality. When abnormal fluctuations occur in the effluent turbidity or dissolved oxygen content, the monitoring data can be fed back to the control system as an auxiliary judgment basis in addition to differential pressure control, so as to more accurately trigger the backwashing procedure and ensure that the effluent water quality consistently meets the standards.

[0053] Furthermore, the backwash water flow direction of the backwash system is opposite to that of the product water flow direction, adopting a reverse flushing mode. After the backwash water flows sequentially through the sponge iron deoxygenation layer B and the quartz sand filter layer A, it flushes the composite filter layer in a countercurrent manner. Finally, the impurities trapped are discharged from the top backwash drain outlet and flow to the discharge tank 10 through the backwash water drain pipe 6.

[0054] Furthermore, the device satisfies the filter media synergy index (SFI) being greater than 0.7, where SFI is defined as follows:

[0055]

[0056] In the formula: The pressure differential increment of the composite filter layer containing the quartz sand filter layer during the standard test cycle; The pressure difference increment of a pure sponge iron deoxygenation layer without a quartz sand filter layer under the same test conditions; This refers to the dissolved oxygen concentration in the influent. This refers to the dissolved oxygen concentration in the effluent.

[0057] Furthermore, to facilitate the operation, control, and maintenance of the device, an automatic water inlet valve 2-2 and a manual water isolation valve 2-1 are sequentially installed on the water inlet pipe 2 at the front end of the inlet, and an automatic water production valve 3-1 is installed on the water production pipe 3 at the rear end of the outlet. The automatic water inlet valve 2-2 and the automatic water production valve 3-1 work together and are uniformly scheduled by the control system to achieve automatic switching during normal operation of the device and backwashing process; the manual water isolation valve 2-1 is used for reliable isolation during maintenance of the water inlet pipe 2.

[0058] like Figure 1 As shown, the device also includes a dosing system for adding chemicals to the incoming water. The dosing system includes a pipe mixer 13 installed on the incoming water pipe 2. A flow meter 11 for real-time monitoring of the incoming water flow is installed upstream (front end) of the pipe mixer 13. The pipe mixer 13 is connected to a dosing pipe 12, on which a check valve 12-1 and a shut-off valve 12-2 are installed in sequence. The check valve 12-1 is used to prevent backflow of chemicals, and the shut-off valve 12-2 is used to control the flow of chemicals.

[0059] A method for applying a multi-effect anti-caking, deoxygenating, and filtration integrated device includes the following steps:

[0060] (1) Water production operation steps: Open the automatic water inlet valve 2-2 at the front end of the inlet and the automatic water production valve 3-1 at the rear end of the outlet; the water flows through the quartz sand filter layer A and the sponge iron deoxygenation layer B in sequence. First, the quartz sand filter layer A intercepts the suspended solids in the water, and then the sponge iron deoxygenation layer B removes dissolved oxygen through oxidation-reduction reaction. The purified water is discharged from the bottom outlet.

[0061] (2) Backwashing steps: When the pressure difference between the inlet and outlet water of tank 1 reaches the set threshold or the operation reaches the set time, the control system closes the automatic water inlet valve 2-2 and the automatic water production valve 3-1, and at the same time starts the backwashing system; the backwash water enters the composite filter layer evenly from bottom to top through the water distribution system, flows through the sponge iron deoxygenation layer B and the quartz sand filter layer A in sequence, and performs integrated backwashing on the composite filter layer. The cleaning wastewater is discharged from the top backwash drain outlet through the backwash water drain pipe 6 into the drainage pool 10. After the backwashing is completed, the device automatically returns to the water production operation state.

[0062] It should be noted that this device can also employ a separate arrangement of the quartz sand filter and the sponge iron filter. However, this separate design not only increases the number of devices, leading to a more complex system process and more control points, but also significantly increases the floor space required due to the parallel installation of multiple devices. Furthermore, the number of auxiliary facilities such as piping, valves, and instruments also increases, thereby driving up the initial investment cost. In contrast, this device combines the quartz sand filter layer and the sponge iron deoxygenation layer within the same tank, effectively simplifying the process, saving installation space, and reducing construction and operation costs.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-effect anti-caking, deoxygenating, and filtration integrated device, characterized in that: The system includes a tank, a composite filter layer, and a backwashing system. The tank has an inlet at the top, an outlet at the bottom, a water distribution system at the bottom, and a backwash drain at the top. The composite filter layer is filled inside the tank and consists of a quartz sand filter layer and a sponge iron deoxygenation layer from top to bottom, with the quartz sand filter layer and the sponge iron deoxygenation layer in direct contact. The backwashing system is connected to the water distribution system and is used to introduce backwash water into the water distribution system to perform integrated backwashing of the composite filter layer. The water distribution system is located at the bottom of the composite filter layer.

2. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 1, characterized in that: The tank body is made of carbon steel lined with rubber.

3. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 1, characterized in that: The density of the quartz sand filter material used in the quartz sand filter layer is lower than that of the sponge iron filter material used in the sponge iron deoxygenation layer, and the particle size of the quartz sand filter material is smaller than that of the sponge iron filter material.

4. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 1, characterized in that: The backwashing system includes a backwash water pump, a backwash water inlet pipe, and a control system; the backwash water inlet pipe is equipped with a manual backwash water isolation valve and an automatic backwash water inlet valve.

5. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 4, characterized in that: The control system includes a differential pressure sensor, which is used to detect the pressure difference between the inlet and the outlet, and triggers the backwashing system to start when the pressure difference reaches a set threshold.

6. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 4, characterized in that: The control system also includes an effluent water quality monitor, which includes a turbidity meter and a dissolved oxygen meter, used to monitor the effluent water quality to help determine the timing of backwashing.

7. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 1, characterized in that: The backwash water flow direction of the backwash system is opposite to that of the product water flow direction. After passing through the sponge iron deoxygenation layer and the quartz sand filter layer in sequence, the backwash water is discharged from the backwash drain outlet.

8. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 1, characterized in that: The device satisfies the filter media synergy index (SFI) being greater than 0.7, whereby SFI is defined as follows: In the formula: The pressure differential increment of the composite filter layer containing the quartz sand filter layer during the standard test cycle; The pressure difference increment of a pure sponge deoxygenation layer without a quartz sand filter layer under the same test conditions; This refers to the dissolved oxygen concentration in the influent. This refers to the dissolved oxygen concentration in the effluent.

9. The multi-effect anti-caking, deoxygenation, and filtration integrated device according to claim 1, characterized in that: The inlet is equipped with a manual water isolation valve and an automatic water inlet valve at the front end, and the outlet is equipped with an automatic water production valve at the rear end.

10. A method for applying the multi-effect anti-caking, deoxygenation, and filtration integrated device as described in any one of claims 1-9, characterized in that, Includes the following steps: Water production operation steps: Open the automatic water inlet valve at the front of the inlet and the automatic water production valve at the rear of the outlet to allow the incoming water to enter the tank. First, the water passes through the quartz sand filter layer to remove suspended solids, then through the sponge iron deoxygenation layer to remove dissolved oxygen, and finally it is discharged from the outlet. Backwashing steps: When the pressure difference between the inlet and outlet water of the tank reaches the set threshold or the operation reaches the set time, close the automatic water inlet valve and the automatic water production valve, and turn on the backwashing system to allow backwash water to enter from the bottom water distribution system and flow from bottom to top through the sponge iron deoxygenation layer and the quartz sand filter layer to clean the composite filter layer in one go. The cleaning wastewater is discharged from the top backwash drain outlet. After the backwashing is completed, the water production operation is restored.

Images