Backwash filtering device and method based on electromagnetic regulation and control

Abstract

The invention discloses a backwash filtering device and method based on electromagnetic regulation and control, the device comprises a filter tank shell, a composite filter layer arranged in the filter tank shell and an electromagnetic system, the composite filter layer comprises a magnetic filter material and a non-magnetic filter material; the electromagnetic system comprises an electromagnet generator and a magnetic field generation unit arranged around the filter tank shell; the magnetic field generating unit comprises a plurality of electromagnetic iron cores and coils wound on the electromagnetic iron cores; the electromagnet generator is electrically connected with the coil through a wire and provides direct current or alternating current for the coil. The device guides the magnetic filter material to generate space reconstruction or micro-vibration through the alternating action of the direct-current magnetic field and the alternating-current magnetic field in the backwashing stage, so that the washing effect of the filter layer is enhanced, and the backwashing efficiency is improved. The device realizes low energy consumption, low water consumption and efficient backwashing, has the advantages of compact structure, high automation degree and strong adaptability, and is suitable for the solid-liquid separation process of mine drainage water, industrial circulating water and sewage treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water treatment equipment, and particularly relates to a backwashing filter device and method based on electromagnetic regulation, which is used for solid-liquid separation and filtration system in industrial circulating water, mine dewatering water and sewage treatment. BACKGROUND

[0002] In the process of treating mine dewatering water, a large amount of suspended particles, colloids and impurities are contained in the water, which can easily cause pipeline blockage, heat exchange efficiency reduction or equipment corrosion. Therefore, a filter, a mechanical filter or a multi-medium filter is usually arranged in the water treatment system to remove suspended solids. The existing conventional filter equipment mainly uses quartz sand or anthracite as filter material to realize solid-liquid separation through gravity filtration. When the filter layer is polluted and blocked, impurities need to be removed through backwashing to restore the filtration performance. However, the existing technology has the following problems: (1) filter layer is easy to be caked and backwashing is not thorough: the conventional backwashing only relies on the backwater flow to flush, the filter material gap is small and the resistance is large, and the impurities are easy to be retained, so the backwashing effect is poor. (2) high energy consumption and large water consumption: in order to achieve the ideal washing effect, the backwashing flow and pressure need to be increased, which significantly increases the energy consumption and water consumption. (3) short service life of filter material: frequent high-intensity backwashing can easily cause filter material abrasion and loss, affecting the service life.

[0003] In view of the above problems, how to improve the backwashing effect, reduce the energy consumption and prolong the service life of the filter material while ensuring the filtration precision has become a key problem to be solved in the current technology. SUMMARY

[0004] In view of the problems of poor backwashing effect, easy abrasion of filter material and high operation energy consumption of the existing filter equipment, the present application provides a backwashing filter device and method based on electromagnetic regulation. The device uses electromagnetic regulation technology to accurately regulate the structure and movement state of the filter material, thereby significantly improving the backwashing effect, reducing the operation energy consumption and prolonging the service life of the filter material. The present application is especially suitable for solid-liquid separation processes such as mine dewatering water, industrial circulating water and sewage treatment, and has important significance for improving the filter cleaning effect and filtration precision.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] In a first aspect, a backwashing filter device based on electromagnetic regulation comprises a filter tank shell, a composite filter layer arranged in the filter tank shell, and an electromagnetic system, wherein:

[0007] The composite filter layer comprises magnetic filter material and non-magnetic filter material;

[0008] The electromagnetic system comprises an electromagnet generator and a magnetic field generating unit arranged around the filter tank shell; the magnetic field generating unit comprises a plurality of electromagnet cores and coils wound around the electromagnet cores; the electromagnet generator is electrically connected to the coils by wires and provides direct current or alternating current to the coils.

[0009] The application further provides that the backwashing filter device further comprises a shell sleeved outside the filter tank shell, and a hollow interlayer is formed between the shell and the filter tank shell, and the magnetic field generating unit is arranged in the hollow interlayer.

[0010] The application further provides that the electromagnet cores are uniformly distributed in the hollow interlayer, and adjacent electromagnet cores are connected to each other by a magnetic conductive support to form a closed magnetic circuit, so as to ensure the uniformity and stability of the magnetic field distribution.

[0011] The application further provides that the coils are arranged in a staggered manner to reduce eddy current loss and improve the response speed of the magnetic field.

[0012] The application further provides that the volume ratio of the magnetic filter material to the non-magnetic filter material is 1:1 to 3:1.

[0013] The application further provides that the magnetic filter material is a soft magnetic material capable of being magnetized repeatedly, and is selected from one or more of magnetite, ferrite and ceramic microbeads coated with a magnetic alloy coating.

[0014] The application further provides that the non-magnetic filter material is selected from one or more of quartz sand, anthracite and ceramsite.

[0015] The application further provides that a filter screen is further arranged below the composite filter layer to support the filter material and prevent the filter material from being lost.

[0016] In a second aspect, a method using the backwashing filter device based on electromagnetic regulation is provided, and the method comprises the following steps.

[0017] S1 backwashing starting stage:

[0018] When the filtration resistance rises to a set threshold or it is automatically judged that cleaning is needed according to the running time, the backwashing filter device enters a backwashing mode; the electromagnet generator is started and direct current is input, and under the action of the direct current magnetic field, the magnetic filter material is arranged along the magnetic force line direction to form a magnetic chain structure, the volume of the filter layer is expanded, and the porosity is significantly increased; at this time, the backwashing water penetrates the composite filter layer from bottom to top, and washes away and carries away the impurities intercepted.

[0019] S2 backwashing strengthening stage:

[0020] When the pressure difference in the filter layer drops to the preset value, the electromagnet generator switches to pass alternating current, and in the alternating magnetic field mode, due to the periodic change of the alternating magnetic field, the magnetic filter material vibrates slightly, so that the relative movement between the magnetic filter material and the non-magnetic filter material is generated, a "stirring type" cleaning effect is formed, thereby further stripping the attached pollutants, and the cleaning effect is improved.

[0021] S3 reset stage:

[0022] After backwashing is completed, the electromagnet generator is turned off, the magnetic field disappears, the magnetic filter material loses the magnetic attraction, and under the action of gravity, the magnetic filter material and the non-magnetic filter material naturally fall back and re-form a dense composite filter layer, and the filtering state is restored.

[0023] Compared with the prior art, the application has the beneficial effects as follows:

[0024] (1) The application innovatively uses a controllable electromagnetic field to dynamically adjust the structure and motion state of the filter material. In the traditional filter equipment, the backwashing process depends on the reverse flushing of the water flow, but this method often cannot effectively remove the fine impurities in the filter material, and is easy to cause the accumulation, caking or wear of the filter material. Through the precise control of the electromagnetic field, the spatial arrangement and dynamic behavior of the magnetic filter material can be adjusted as needed during the filtering and backwashing processes, so that the cleaning effect of the filter material is effectively optimized, the backwashing efficiency is improved, and the retention of the attached material on the surface of the filter material is avoided.

[0025] (2) In the backwashing stage, the magnetic filter material is guided to undergo spatial reconstruction or micro-vibration through the alternating action of the direct current and alternating current magnetic field of the electromagnetic system. Under the direct current magnetic field, the magnetic filter material is arranged along the magnetic force line direction to form a magnetic chain similar to a floating internal component, which promotes the loosening of the filter layer as a whole, the expansion of the pore, and the volume expansion of the filter layer, thereby significantly enhancing the flowability of the backwashing channel. Under the action of the alternating current magnetic field, the micro-vibration effect of the magnetic filter material can cause the particles between the filter materials to collide and rub, thereby effectively removing the sludge, colloids and fine suspended solids attached to the surface of the filter material, and enhancing the thoroughness of backwashing. This dual action makes the cleaning of the filter material more uniform and efficient, and avoids the problem of residual impurities in the traditional backwashing method.

[0026] (3) The energy consumption and water consumption are low, the magnetic control expansion and micro-vibration auxiliary cleaning mechanism significantly reduce the backwashing water flow rate and pressure required to achieve the ideal cleaning effect, thereby greatly saving the energy consumption and the amount of flushing water, and meeting the energy saving and environmental protection requirements. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 is the overall structure schematic diagram of the backwashing filter device based on electromagnetic control.

[0028] Figure 2is the internal structure schematic diagram of the backwash filter device based on electromagnetic regulation of the present application (not powered).

[0029] Figure 3 A and Figure 3 B are the structural schematic diagrams of the split shell and filter tank shell respectively.

[0030] Figure 4 is the electromagnetic core arrangement schematic diagram.

[0031] Figure 5 is the schematic diagram of the coil winding electromagnetic core.

[0032] Figure 6 A and Figure 6 B are the arrangement diagrams of the filter material before and after power-on of the backwash filter device based on electromagnetic regulation of the present application respectively.

[0033] In the figure: filter tank shell 1; medium inlet 11; medium outlet 12; backwash inlet 13; backwash outlet 14; discharge port 15; feed port 16; composite filter layer 2; magnetic filter material 21; non-magnetic filter material 22; electromagnet generator 3; electromagnetic core 31; coil 32; shell 4; circular structure 41; filter screen 5; foot 6. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0035] As Figures 1-4 shown, the backwash filter device based on electromagnetic regulation of the present application comprises a filter tank shell 1, a composite filter layer 2 arranged in the filter tank shell 1, and an electromagnetic system, wherein: the composite filter layer 2 comprises magnetic filter material 21 and non-magnetic filter material 22 (see Figure 6 ); the electromagnetic system comprises an electromagnet generator 3 and a magnetic field generating unit arranged around the filter tank shell 1; in combination Figure 5 shown, the magnetic field generating unit comprises a plurality of electromagnetic cores 31, and each electromagnetic core 31 is uniformly wound with multiple turns of enameled copper wire outside to form a coil 32; the electromagnet generator 3 is electrically connected with the coil 32 through a wire and provides direct current or alternating current to it, and regulates the current direction, intensity and waveform.

[0036] When the electromagnet generator 3 is powered on, the coil 32 generates a circumferential magnetic field around the electromagnet core 31, which penetrates through the filter tank shell 1 and acts on the magnetic filter material 21 in the composite filter layer 2, realizing the spatial reconstruction and flow regulation of the magnetic filter material 21.

[0037] The backwashing filter device further comprises an outer shell 4 sleeved outside the filter tank shell 1, a hollow interlayer is formed between the outer shell 4 and the filter tank shell 1, and the magnetic field generating unit is arranged in the hollow interlayer. The filter tank shell 1 and the outer shell 4 are preferably made of steel structure, having good mechanical strength and pressure resistance. The hollow interlayer is supported by the upper circular structure 41 and fixedly connected with the filter tank shell 1. The bottom of the outer shell 4 is further provided with a supporting leg 6 for supporting and fixing.

[0038] The electromagnet cores 31 are uniformly distributed in the hollow interlayer, and adjacent electromagnet cores 31 are connected with each other by a magnetic conductive support (not shown in the figure) to form a closed magnetic circuit, so as to ensure the uniformity and stability of the magnetic field distribution. The coil 32 adopts staggered wiring to reduce eddy current loss and improve the response speed of the magnetic field.

[0039] The outer shell 4 is further provided with a medium inlet 11, a medium outlet 12, a backwashing inlet 13, a backwashing outlet 14, a discharge port 15 and a feeding port 16 which are in communication with the inside of the filter tank shell 1, for realizing the medium flow switching and the loading and unloading of the filter material during the filtering and backwashing processes.

[0040] In the composite filter layer 2, the mixed volume ratio of the magnetic filter material 21 to the non-magnetic filter material 22 is 1:1-3:1, which can be flexibly adjusted according to the suspended solid concentration and particle size in the influent water. The appropriate amount of magnetic filter material 21 can ensure that the filter layer has adjustable void and strong disturbance capacity, and the appropriate amount of non-magnetic filter material 22 can avoid the risk of filter layer hardening caused by magnetic agglomeration. If the magnetic filter material 21 is too much or all the magnetic filter material 21 is used, it is easy to form hard magnetic chains or magnetic groups under the action of the magnetic field due to the close connection of the magnetic filter material 21 at the head and tail, which may cause excessive compaction or “magnetization hardening” of the filter layer. This structure will change the filter layer from a loose state to a rigid and dense solid network, forming a fluid dead zone and causing a significant increase in pressure drop. Therefore, a certain proportion of non-magnetic filter material 22 must be mixed to maintain the stability and smoothness of the filter layer structure.

[0041] The magnetic filter material 21 is a soft magnetic material that can be magnetized repeatedly, such as magnetite, ferrite and ceramic microbeads coated with a magnetic alloy coating, which has the characteristics of repeated magnetization, small residual magnetism and fast response; the non-magnetic filter material 22 can be selected from conventional media such as quartz sand, anthracite and ceramsite, which is used to form a composite pore structure.

[0042] Below the composite filter layer 2, a filter screen 5 is also provided to support the filter material and prevent it from being lost. The filter screen 5 adopts a stainless steel screen structure with a pore size range of 50~200µm, which can effectively trap fine suspended particles.

[0043] like Figure 6 As shown, during the filtration stage, the electromagnet generator 3 is not energized, and the magnetic filter media 21 and non-magnetic filter media 22 are uniformly mixed. In the initial stage of backwashing, the electromagnet generator 3 uses DC power. The magnetic filter media 21, under the influence of the magnetic field, aligns along the magnetic lines of force to form magnetic chains similar to floating internal components, expanding the filter media gaps and facilitating backwashing. Simultaneously, the rigid chain network formed by the magnetic chains maintains a stable pore structure within the composite filter layer 2, preventing pressure drop spikes caused by dust blockage. In the later stage of backwashing, the electromagnet generator 3 switches to AC power mode, using an alternating magnetic field to induce micro-vibrations in the magnetic filter media 21, promoting mutual friction between the filter media and enhancing the removal and cleaning effect of attached particles. The output time of the electromagnet generator 3 for both DC and AC power can be adjusted according to the actual contamination level of the material. When contamination is severe, the DC power stage time can be increased; while when high cleaning precision is required, the AC power stage time can be appropriately extended.

[0044] The method using the above-mentioned electromagnetically controlled backwashing filter includes the following steps:

[0045] S1 Filtering Stage:

[0046] When the device is in the filtration stage, the media inlet 11 and media outlet 12 are open, the backwash inlet 13 and backwash outlet 14 are closed, the electromagnet generator 3 is closed, there is no magnetic field inside the filter tank 1, and the magnetic filter media 21 and non-magnetic filter media 22 naturally accumulate under the action of gravity to form a dense composite filter layer 2; the liquid to be treated enters the filter tank 1 through the media inlet 11 and passes through the composite filter layer 2 from top to bottom. Suspended solids are trapped above the filter layer or in the gaps between the filter media, and the purified liquid is discharged from the media outlet 12; after long-term operation, the gaps in the filter layer are gradually blocked by suspended particles, and the filtration pressure difference increases.

[0047] S2 backwash start-up phase:

[0048] When the filtration differential pressure rises to the set threshold or the system automatically determines that cleaning is required based on the running time, the system enters the backwashing stage. The media inlet 11 and media outlet 12 are closed, and the backwash inlet 13 and backwash outlet 14 are opened. At the same time, the electromagnet generator 3 is started and DC power is supplied. Under the action of the DC magnetic field, the magnetic filter media 21 is arranged along the direction of the magnetic lines of force to form a magnetic chain structure. The volume of the composite filter layer 2 expands and the porosity increases significantly. At this time, the backwash water enters through the backwash inlet 13, penetrates the composite filter layer 2 from bottom to top, washes away and carries away the trapped impurity particles, and is discharged from the backwash outlet 14.

[0049] S3 backwash reinforcement stage:

[0050] When the filtration pressure difference drops to the preset value, the electromagnet generator 3 is switched to pass alternating current. In the alternating magnetic field mode, due to the periodic change of the alternating magnetic field, the magnetic filter material 21 vibrates slightly, causing relative motion between the magnetic filter material 21 and the non-magnetic filter material 22, forming a "stirring" cleaning effect, thereby further stripping the attached pollutants and improving the cleaning effect. This micro-scale vibration can effectively strip the fine sludge, oil film and colloidal substances attached to the surface of the filter material, and the backwashing is more thorough;

[0051] S4 reset stage:

[0052] After backwashing, the electromagnet generator 3 is turned off, the magnetic field disappears, and the magnetic filter material 21 loses its magnetic attraction and naturally falls back under the action of gravity and re-forms a dense composite filter layer 2, restoring the filtration state.

[0053] Backwashing effect test

[0054] The electromagnetic control method of the backwashing filtration device based on electromagnetism and the influence of the mixed filter material ratio on the backwashing effect are verified through the following comparison tests. All test examples are carried out under the same backwashing filtration pressure difference (pollution level), backwashing water flow rate, pressure and time. Among them, when the electromagnetic control is carried out, the current direction, intensity and waveform are the same.

[0055] Test condition setting:

[0056] Test group A (all magnetic + electromagnetic control): The filter material is 100% magnetic filter material magnetite, and the electromagnetic control program (first DC and then AC) is enabled during backwashing.

[0057] Test group B (mixed + electromagnetic control): The filter material is a mixture of magnetite and quartz sand in a volume ratio of 1:1, and the same electromagnetic control program as test group A is enabled during backwashing.

[0058] Test group C (mixed + DC): The filter material is a mixture of magnetite and quartz sand in a volume ratio of 1:1, and only DC magnetic field is used during backwashing.

[0059] Test group D (mixed + AC): The filter material is a mixture of magnetite and quartz sand in a volume ratio of 1:1, and only AC magnetic field is used during backwashing.

[0060] Test group E (mixed + traditional backwashing): The filter material is a mixture of magnetite and quartz sand in a volume ratio of 1:1, and the electromagnetic system is turned off during backwashing, and only hydraulic backwashing is performed.

[0061] Test method and result:

[0062] The test is carried out by the foregoing method, and the core measurement index is the initial filtration pressure difference when the system recovers filtration after backwashing is completed and the reset is placed. The lower the value, the better the cleaning and structure recovery effect of the filter layer. The test data are recorded in Table 1 as follows:

[0063] Table 1

[0064]

[0065] Result analysis:

[0066] As can be seen from the comparison test groups B to E, under the same proportion of mixed filter material, the filtration pressure difference after the electromagnetic control backwashing (group B) of the application is significantly lower than that of the traditional hydraulic backwashing (group E). Although the backwashing using the direct current magnetic field (group C) or the alternating current magnetic field (group D) is better than the traditional hydraulic backwashing (group E), it is far from the electromagnetic control backwashing (group B) of the application. The reason is that when only the direct current magnetic field is used for cleaning, it cannot effectively remove the pollutants firmly attached to the surface of the filter material, and fixed channels are easily formed to cause uneven cleaning. When only the alternating current magnetic field is used for cleaning, the porosity of the filter layer is limited, and the water flow resistance is still large. The pollutants stripped by vibration may not be effectively carried out by the water flow, and "secondary retention" is easily caused, the backwashing efficiency is low, and a large amount of water is used. It is proved that the regulation and control method of the alternating action of the direct current and the alternating current magnetic field can effectively improve the cleaning effect of the filter layer.

[0067] As can be seen from the comparison of test groups A and B, under the same electromagnetic regulation program, the filtration pressure difference after the backwashing of the filter material mixed at a ratio of 1:1 (group B) is much lower than that of the full magnetic filter material (group A). This is because the use of the full magnetic filter material will cause the filter layer to be excessively compacted and "magnetized and hardened" in the magnetic field, which is not conducive to cleaning. The incorporation of non-magnetic filter material can effectively maintain the stability and smoothness of the pore structure of the filter layer, which is a necessary condition to ensure the electromagnetic regulation effect.

[0068] In summary, the test results fully show that the mixed filter material combined with the electromagnetic regulation backwashing method of the direct current first and then the alternating current can synergistically achieve the optimal backwashing effect.

[0069] The above is only a preferred specific embodiment of the application, but the protection scope of the application is not limited thereto. Any person skilled in the art can make equivalent replacements or changes to the technical solution and the inventive concept of the application within the technical scope disclosed by the application, which should be covered within the protection scope of the application.

Claims

1. A backwashing filter device based on electromagnetic control, characterized in that, The backwashing filtration device includes a filter tank, a composite filter layer disposed within the filter tank, and an electromagnetic system, wherein: The composite filter layer includes magnetic filter media and non-magnetic filter media; The electromagnetic system includes an electromagnet generator and a magnetic field generating unit surrounding the filter canister; the magnetic field generating unit includes several electromagnet cores and a coil wound around the electromagnet cores; the electromagnet generator is electrically connected to the coil via a wire and provides it with direct current or alternating current.

2. The backwashing filter device based on electromagnetic control according to claim 1, characterized in that, The backwashing filter device also includes an outer shell fitted outside the filter tank shell, with a hollow interlayer formed between the outer shell and the filter tank shell, and the magnetic field generating unit disposed within the hollow interlayer.

3. The backwashing filter device based on electromagnetic control according to claim 2, characterized in that, The electromagnet cores are evenly distributed within the hollow interlayer, and adjacent electromagnet cores are interconnected through magnetic guide supports to form a closed magnetic circuit.

4. The backwashing filter device based on electromagnetic control according to claim 1, characterized in that, The coil uses an interleaved wiring method.

5. The backwashing filter device based on electromagnetic control according to claim 1, characterized in that, The mixing volume ratio of the magnetic filter material to the non-magnetic filter material is 1:1 to 3:

1.

6. The backwashing filter device based on electromagnetic control according to claim 1, characterized in that, The magnetic filter material is a soft magnetic material that can be repeatedly magnetized, selected from one or more of magnetite, ferrite, and ceramic microspheres coated with magnetic alloys.

7. The backwashing filter device based on electromagnetic control according to claim 1, characterized in that, The non-magnetic filter material is selected from one or more of quartz sand, anthracite, and ceramsite.

8. The backwashing filter device based on electromagnetic control according to claim 1, characterized in that, A filter screen is also provided below the composite filter layer.

9. A method using the electromagnetically controlled backwashing filter device according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1 backwash start-up phase: When the filtration resistance rises to the set threshold or when cleaning is automatically determined based on the running time, the backwash filter enters the backwash mode; the electromagnet generator is started and DC power is applied. Under the action of the DC magnetic field, the magnetic filter media are arranged along the direction of the magnetic lines of force to form a magnetic chain structure, the filter layer volume expands, and the porosity increases significantly; at this time, the backwash water penetrates the composite filter layer from bottom to top, flushing and carrying away the trapped impurities. S2 backwashing enhancement stage: When the pressure difference inside the filter layer drops to the preset value, the electromagnet generator switches to AC power. In AC magnetic field mode, due to the periodic change of the alternating magnetic field, the magnetic filter material vibrates slightly, causing relative motion between it and the non-magnetic filter material, forming a "stirring" cleaning effect, thereby further removing attached pollutants and improving the cleaning effect. S3 reset phase: After backwashing, turn off the electromagnet generator. The magnetic field disappears, the magnetic filter media loses its magnetic attraction, and it naturally falls back with the non-magnetic filter media under the action of gravity, reforming a dense composite filter layer and restoring the filtration state.

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