Liquid Filtration Methods and Systems

Abstract

This disclosure relates to a liquid filtration method (100, 300, 500) for filtering liquid to remove waste. The liquid filtration method (100, 300, 500) includes filtering the liquid using a first filter (FT1) and discharging a first filtered liquid from the first filter (FT1), the first filter (FT1) accumulating waste filtered from the liquid. The first filter (FT1) is flushed with a flushing fluid to remove at least some of the accumulated waste from the first filter (FT1), and the flushing fluid and at least some of the waste removed from the first filter (FT1) are discharged. The flushing fluid discharged from the first filter (FT1) is filtered using a second filter (FT2), and a second filtered liquid is discharged from the second filter (FT2), the second filter accumulating waste filtered from the flushing fluid. The second filter (FT2) comprises an open-pore filter medium containing a plurality of filter elements (43) forming a static filter pack (FP1), each of the filter elements (43) having one or more filter cells (15), the static filter pack (FP1) filtering the flushing fluid discharged from the first filter (FT1). This disclosure also relates to a liquid filtration system (1).

Description

Technical Field

[0001] This disclosure relates to liquid filtration methods and systems. Aspects of the invention relate to filtration methods and systems for filtering liquids (such as water). Background Technology

[0002] It is well known that liquids (such as water) are filtered to remove waste. Filters are used to separate waste from liquids. The waste may contain solids or consist of solids that are filtered out by the filter. Waste accumulates on the filter, causing it to become clogged. It is well known to supply washing liquid to flush the filter. The washing liquid may be, for example, backwashing liquid, which is introduced to reverse the flow direction through the filter. The washing liquid may be supplied under high pressure to disperse the accumulated waste. The washing liquid removes at least some of the accumulated waste from the filter. The washing liquid and the removed waste are discharged to a waste disposal site. The frequency of filter flushing depends on the particulate load of the liquid being filtered. Large amounts of washing liquid may be required to keep the filter clean for effective filtration.

[0003] The purpose of this invention is to address one or more drawbacks associated with the prior art. Summary of the Invention

[0004] The present invention provides a liquid filtration method, a liquid treatment method, a liquid filtration system, and a liquid treatment method as described in the appended claims.

[0005] According to a present invention, a liquid filtration method is provided for filtering liquid to remove waste, the liquid filtration method comprising:

[0006] The liquid is filtered using a first filter and a first filtered liquid is discharged from the first filter, the first filter accumulating waste material filtered from the liquid;

[0007] The first filter is flushed with a flushing solution to remove at least some of the accumulated waste from the first filter, and the flushing solution and at least some of the removed waste are discharged from the first filter; and

[0008] The flushing liquid discharged from the first filter is filtered using a second filter, and a second filtered liquid is discharged from the second filter, which accumulates waste filtered from the flushing liquid.

[0009] The second filter includes an open-pore filter medium containing multiple filter elements that form a static filter pack. Each filter element has one or more filter cells. The static filter pack filters the flushing liquid discharged from the first filter.

[0010] The liquid supplied to the first filter (i.e., the influent) may be referred to as raw or unfiltered liquid. This liquid contains waste. The waste may contain or consist of solids (i.e., solid substances insoluble in the liquid; or solid substances precipitated from the solution, for example, in the form of a precipitate). The waste may contain or consist of one or more of the following: particles, microparticles, fine particles, small particles, flocs, agglomerates, or other forms of solid matter. The waste is transported by the liquid and may, for example, be suspended in the liquid. During the filtration process, the first filter filters the waste from the liquid. During the filtration process, the filtered waste accumulates on the first filter. The accumulated waste may form a filter cake or precipitate on the first filter.

[0011] The first filter mechanically filters the liquid to trap solid waste or particulate matter. The first filter may comprise one of the following: a filter bed, a sand bed filter, an activated carbon filter, a multi-media filter, or a particulate filter. The first filter may contain a first filter medium. The first filter medium may form a first filter bed. The first filter medium may, for example, contain particles, fine particles, or beads. The first filter medium may contain or be composed of filter elements having a closed structure, i.e., at least substantially without internal cavities or orifices. The first filter medium may, for example, contain sand, gravel, or glass beads. The liquid passes through the first filter bed. Waste suspended in the liquid is trapped in the cavities between the first filter media. The first filter bed thereby separates the waste from the liquid. For example, this type of first filter bed is used to filter purified water. In a variation, the first filter medium may comprise an open-pore filter medium. The open-pore filter medium may comprise multiple filter elements forming a static filter bag. Each filter element has one or more filter cells. The static filter bag filters the liquid.

[0012] Alternatively, the first filter may comprise a first screen filter. The first screen filter may comprise or be composed of filter meshes. The first screen filter may be cylindrical. The first filter may be, for example, a drum filter.

[0013] The first filter is flushed with a flushing fluid to maintain its operation. In at least some embodiments, the flushing fluid is used to disperse waste material accumulated on the first filter. The liquid filtration method may include supplying flushing fluid to flush the first filter. The flushing fluid may be introduced into the first filter to remove at least some of the accumulated waste material. During filtration, the flushing fluid may pass through the first filter in the same direction as the liquid. For example, the flushing fluid may be supplied under high pressure to break down the accumulated waste material. Alternatively, during filtration, the flushing fluid may pass through the first filter in the opposite direction to the liquid. The flushing fluid may be a backwash fluid, which reverses the flow direction through the first filter.

[0014] The flushing fluid can be supplied under high pressure (i.e., greater than atmospheric pressure). The flushing fluid can be supplied through at least one flushing fluid inlet. This or each flushing fluid inlet may include a nozzle. This or each nozzle can direct the flushing fluid to a localized area of ​​the first filter.

[0015] Alternatively, or further, the flow direction through the first filter can be reversed to perform backflushing. The flushing fluid may contain or consist of a backflushing fluid. The backflushing fluid may contain or consist of the liquid filtered by the first filter.

[0016] The first filter can be emptied to discharge used (contaminated) flushing fluid and removed waste. The first filter can be discharged through the first filter waste outlet. As the first filter is emptied, the liquid can act as flushing fluid to remove accumulated waste and / or transport at least some of the accumulated waste from the first filter. The liquid present in the first filter can be used as flushing fluid.

[0017] A gas, such as air, may be introduced into the first filter to remove accumulated waste from it. The gas may be introduced under high pressure. The gas may be directed onto the first filter in the form of one or more high-pressure jets. The gas may be directed through the first filter in the same or opposite direction as the liquid flows through it. As illustrated herein, the first filter may comprise a screen filter or filter mesh containing multiple openings. The one or more high-pressure jets may be directed through these openings in the first filter.

[0018] The flushing fluid is discharged from the first filter to the second filter. The flushing fluid carries at least some of the accumulated waste material from the first filter to the second filter. This waste material may, for example, be suspended in the flushing fluid. The flushing fluid discharged from the first filter may be referred to as used (contaminated) flushing fluid.

[0019] At least some of the waste material transported from the first filter along with the flushing fluid is filtered by the second filter. The perforated filter media effectively filters particulate matter from the flushing fluid introduced from the first filter. The flushing fluid is filtered and discharged from the second filter as the second filtered liquid (i.e., the second filtrate). The second filtered liquid discharged from the second filter can be used to flush the first filter during the current flushing method and / or subsequent flushing methods.

[0020] Waste removed by the self-rinsing fluid accumulates in the second filter. The filter element in the second filter has a high retention capacity and, at least in some embodiments, makes it possible to collect waste in the second filter.

[0021] The used flushing fluid is filtered by a second filter to remove at least some of the waste. The flushing fluid is discharged from the second filter as a second filtered liquid. The waste accumulates in the second filter and can be periodically discharged from the second filter for further treatment, such as drying or dewatering, or can be discharged for disposal. The waste discharged from the second filter is concentrated, i.e., has a lower water content than the waste discharged from the first filter. In at least some embodiments, the water filtration method effectively reduces the liquid content of the waste. The liquid filtration method makes it possible to recover at least some of the flushing fluid. The recovered water can be reused or recycled.

[0022] The method may include supplying a second filtered liquid from a second filter to a first filter. At least some of the second filtered liquid may be supplied to the first filter. The second filtered liquid may be supplied directly to the first filter or upstream of the first filter. The second filtered liquid may then be filtered by the first filter.

[0023] The first filtered liquid may be discharged from the first filter to one or more system outlets. Alternatively, or further, at least some of the second filtered liquid may be discharged from the second filter to the one or more system outlets.

[0024] Alternatively, or additionally, at least some of the second filtered liquid discharged from the second filter may be returned to the first filter. The second filtered liquid may be used as a flushing solution for rinsing the first filter.

[0025] Waste from self-rinsing fluid filtration can accumulate in the filter cells of a static filter bag and / or a porous filter medium. The liquid filtration method may include rinsing a second filter to remove at least some of the waste accumulated in the second filter. The rinsing fluid supplied from the first filter can be used as a rinsing liquid to remove at least some of the accumulated waste from the second filter. For example, at least some of the rinsing fluid supplied from the first filter can be discharged to rinse the second filter. The waste accumulated in the second filter can be discharged together with at least some of the rinsing fluid supplied from the first filter. Alternatively, or further, a separate rinsing liquid can be introduced into the second filter.

[0026] The supply of flushing fluid from the first filter to the second filter can be stopped when flushing the second filter. For example, the fluid connection between the first filter and the second filter can be closed.

[0027] The flushing of the second filter may involve introducing fluid into the second filter to break up the static filter pack and / or remove waste from the filter cells. The fluid may be referred to as pack disruption fluid. A pump may be provided to pump the fluid into the second filter under pressure. Alternatively, the fluid may be drawn into the second filter when the flushing fluid is discharged. The second filter may be sealed such that pack disruption fluid is drawn into the second filter when the flushing fluid is discharged. The fluid may contain a gas such as air; or a liquid such as water.

[0028] A liquid filtration method may include a filtration method and a rinsing method. The first filter filters the liquid in the filtration method. The first filter may be rinsed during the rinsing method. The filtration method and the rinsing method may be performed sequentially or simultaneously. A second filter may be rinsed while performing the filtration method and / or the rinsing method. The rinsing of the second filter may be performed simultaneously with the liquid filtered by the first filter. The rinsing of the second filter may be performed after the rinsing method. Alternatively, the rinsing of the second filter may be performed as part of the rinsing method. The rinsing of the second filter may be performed simultaneously with the filtration method.

[0029] In at least some embodiments, the filtration and rinsing methods are performed sequentially. The liquid filtration method may alternate between the filtration and rinsing methods. In at least some embodiments, the filtration method may restart after the rinsing method is completed.

[0030] A liquid filtration method may include establishing a first flow rate per unit cross-sectional area through a first filter and a second flow rate per unit cross-sectional area through a second filter. The first flow rate per unit cross-sectional area may be greater than the second flow rate per unit cross-sectional area.

[0031] The first and second filters may comprise a first open-pore filter medium and a second open-pore filter medium, such as the type of open-pore filter medium described herein. The first filter open-pore filter medium may form a first static filter bag; and the second open-pore filter medium may form a second static filter bag. The first static filter bag may have a first volume; and the second static filter bag may have a second volume. The first volume may be larger than the second volume. The liquid filtration method may include establishing a first flow rate per unit cross-sectional area through the first static filter bag; and a second flow rate per unit cross-sectional area through the second static filter bag. The first flow rate per unit cross-sectional area may be greater than the second flow rate per unit cross-sectional area. The first flow rate per unit cross-sectional area may be two, three, four, or more times the second flow rate per unit cross-sectional area. The flow rate per unit cross-sectional area of ​​the filter medium in the first static filter bag may be greater than or equal to 30 m³ / m² / h, 50 m³ / m² / h, or 70 m³ / m² / h. The flow rate per unit cross-sectional area of ​​the filter medium in the second static filter pack can be in the range of 5 m3 / m2 / h to 35 m3 / m2 / h, 10 m3 / m2 / h to 30 m3 / m2 / h, or 20 m3 / m2 / h to 25 m3 / m2 / h.

[0032] The liquid may be water. In at least some embodiments, the liquid may be purified water, such as water containing or composed of potable (drinking) water. The water may be suitable for human consumption. Alternatively, the liquid may be wastewater, such as municipal or industrial wastewater.

[0033] According to another aspect of the present invention, a liquid treatment method is provided, which includes the liquid filtration method as described herein.

[0034] According to a further embodiment of the present invention, a liquid filtration system is provided for filtering liquid to remove waste, the liquid filtration system comprising:

[0035] The first filter unit includes:

[0036] At least one first filter inlet is provided for receiving the liquid to be filtered;

[0037] The first filter is used to filter waste from the liquid;

[0038] At least one first filter outlet is provided for discharging the first filtered liquid;

[0039] Rinse fluid supply, used to supply rinsing fluid to rinse the first filter; and

[0040] At least one first filter waste outlet for discharging the flushing fluid;

[0041] The second filtering unit includes:

[0042] At least one second filter inlet is provided for receiving the flushing liquid discharged from the first filter unit;

[0043] A second filter is used to filter waste from the flushing fluid; and

[0044] At least one second filter outlet for discharging a second filtered liquid;

[0045] The second filter includes an open-pore filter medium containing multiple filter elements for forming a static filter pack, each filter element having one or more filter cells.

[0046] The liquid filtration system can be configured to optionally operate in a filtration mode and a flushing mode. When operating in filtration mode, the liquid filtration system can be configured to supply liquid to at least one first filter inlet, where the liquid is filtered by a first filter and the first filtered liquid is discharged from a first filter unit through at least one first filter outlet. When operating in flushing mode, the liquid filtration system can be configured to flush the first filter using the flushing fluid. The used (contaminated) flushing fluid is discharged through at least one first filter waste outlet, thereby removing accumulated waste from the first filter. The flushing fluid discharged from the first filter unit is supplied to the second filter unit. The flushing fluid is filtered by an open-pore filter media in the second filter unit. A static filter bag can be used to separate waste from the flushing fluid. The second filtered liquid can be discharged from the second filter unit. In at least some embodiments, the flushing fluid is filtered by the second filter unit and discharged as the second filtered liquid.

[0047] The first filtration unit may include a first filtration chamber. The first filter may be disposed in the first filtration chamber. The at least one first filter inlet and the at least one first filter outlet may be in fluid communication with the first filtration chamber. The first filtration chamber may be formed in a first filtration tank.

[0048] The second filtration unit may include a second filtration chamber. The second filter may be disposed within the second filtration chamber. The plurality of filter elements may form the static filter pack within the second filtration chamber. The at least one second filter inlet and the at least one second filter outlet may communicate with the second filtration chamber. The second filtration chamber may be formed in a second filter tank. The second filtration unit may include a second filter waste outlet for discharging accumulated waste. Alternatively, one of the at least one second filter inlet and the at least one second filter outlet may be used as a waste outlet for discharging accumulated waste.

[0049] The liquid in the first filtration unit can act as a flushing fluid to remove at least some of the accumulated waste from the first filter. The accumulated waste can be flushed out of the first filter when water is discharged from the first filtration unit. Alternatively, or further, the liquid filtration system can be configured to supply flushing fluid to the first filter in this flushing mode. The flushing fluid can be introduced into the first filtration unit to remove accumulated waste from the first filter. The flushing fluid supplied to the first filtration unit can dilute the mixture of liquid and waste in the first filter.

[0050] The liquid filtration system may include at least one flushing fluid inlet for introducing flushing fluid into the first filtration unit. The flushing fluid inlet may be a single inlet, or one of the at least one first inlet and the at least one first outlet may be reconfigured to serve as a flushing fluid inlet. The flushing fluid inlet may include one or more nozzles.

[0051] In use, the liquid to be filtered is supplied to a first filtration unit. The liquid is filtered by the first filter. Waste accumulates in the first filter, and a first filtered liquid is discharged from the first filtration unit. The first filter is flushed with a flushing solution to remove at least some of the accumulated waste. The used (contaminated) flushing solution is discharged from the first filtration unit to the second filtration unit, along with at least some of the accumulated waste from the first filter. The second filter can be used to filter at least some of the waste transported with the flushing solution. The discharged flushing solution is filtered by the perforated filter media, and a second filtered liquid (i.e., a second filtrate) is discharged from the second filtration unit. The flushing solution can be supplied, for example, to the inlet of the at least one second filter. The flushing solution is filtered by the perforated filter media in the second filter chamber. Waste accumulates in a static filter bag.

[0052] The waste filtered by the first filter typically contains or consists of solids (i.e., solid substances insoluble in liquids or solid substances precipitated from solution). The waste may contain or consist of one or more of the following: particles, microparticles, fine particles, small particles, flocs, agglomerates, or other forms of solid matter. The waste is transported by liquid and may, for example, be suspended in the liquid. In use, the first filter is operable to filter the waste from the liquid during the filtration process.

[0053] Filtered waste accumulates in the first filter. A liquid filtration system can be configured to selectively flush the first filter to discharge at least some of the accumulated waste. The liquid filtration system is configured to discharge flushing fluid from the first filter to the second filter. The liquid in the first filter unit can act as flushing fluid to remove at least some of the accumulated waste from the first filter. When water is discharged, the accumulated waste can be flushed out of the first filter unit. Alternatively, or additionally, the flushing method may include supplying flushing fluid to flush the first filter. The liquid filtration system can be configured to supply flushing fluid to the first filter. The flushing fluid can be introduced into the first filter to remove or disperse the accumulated waste from the first filter. The flushing fluid supplied to the first filter can dilute the mixture of liquid and waste in the first filter.

[0054] The used (contaminated) flushing fluid discharged from the first filter unit conveys at least some of the accumulated waste from the first filter unit to the second filter unit. The waste may be suspended in the flushing fluid. The second filter effectively filters at least some of the waste conveyed by the flushing fluid. The filtered liquid is discharged from the second filter as a second filtered liquid. The filtered waste is collected in the second filter. The filter element has a high retention capacity and, at least in some embodiments, allows the waste to be collected in the second filter. At least in some embodiments, the second filter unit may have a smaller volume than the first filter unit. The second filter operates to filter the flushing fluid to remove at least some of the waste from the flushing fluid. The waste accumulates in the second filter and may be periodically discharged for further treatment, such as drying or dehydration, or disposal. The waste discharged from the second filter is concentrated, i.e., has a lower water content than the waste discharged from the first filter.

[0055] The liquid filtration system may include a supply line for supplying the second filtered liquid from the second filtration unit to the first filtration unit. The supply line may be directly connected to the first filtration unit or connected upstream of the first filtration unit. Alternatively, or further, at least one second filtration outlet may be connected to one or more system outlets. In use, the second filtered liquid may be discharged to one or more system outlets.

[0056] The second filter unit can be assembled to flush away at least some of the waste accumulated in the static filter bag. The second filter unit may include at least one second filter waste outlet. Waste accumulated in the second filter unit can be flushed through at least one second filter waste outlet. Alternatively, or further, the second filter can be flushed through one of the second filter inlet and the second filter outlet. The liquid contained in the second filter unit can be used as flushing liquid to remove waste. Alternatively, or further, flushing liquid can be introduced into the second filter. The second filter unit may include one or more inlets for introducing the flushing liquid.

[0057] The second filter unit may include at least one fluid inlet for introducing fluid to remove waste from the filter cell. The fluid may be introduced to disrupt (i.e., break up) the static filter bag formed by the filter elements. The fluid may be referred to as a package breakage fluid. At least one fluid inlet may be configured to introduce liquid or gas into the second filter. At least one fluid inlet may be configured to introduce air into the second filter. A pump may be provided for pumping the fluid into the second filter chamber. Alternatively, or further, fluid may be drawn into the second filter chamber when it is emptied. The second filter chamber may be sealed such that air is drawn into the second filter chamber when the flushing fluid is emptied.

[0058] The liquid filtration system can be configured to selectively operate in filtration mode and / or flushing mode. The liquid filtration system can also be configured to operate sequentially in the filtration mode and the flushing mode. During use, the liquid filtration system can switch between filtration mode and flushing mode.

[0059] The liquid filtration system can be configured to flush the second filter unit when operating in filtration mode and / or flushing mode. Flushing of the second filter can be performed simultaneously with the liquid filtered by the first filter. Flushing of the second filter can be performed after the flushing method. Alternatively, flushing of the second filter can be performed during the flushing mode. Flushing of the second filter can be performed when operating in filtration mode.

[0060] The first filtration unit may include one or more first filtration inlets, one or more first filtration outlets, and one or more first filtration waste outlets. The liquid filtration system may include one or more valves to control the flow of liquid through one or more of the following: the first filtration inlet, the first filtration outlet, and the first filtration waste outlet.

[0061] A first filter inlet valve may be provided to control the water supply to the first filter chamber. A first filter outlet valve may be optionally provided to control the discharge of first filtered water from the first filter unit. A first filter waste valve may be provided to control the discharge of used (contaminated) flushing fluid (and entrained waste) from the first filter chamber to the second filter chamber.

[0062] The second filtration unit may include one or more second filtration inlets, one or more second filtration outlets, and one or more second filtration waste outlets. The liquid filtration system may include one or more valves to control the flow of liquid through one or more of the following: the second filtration inlet, the second filtration outlet, and the second filtration waste outlet.

[0063] A second filter inlet valve may be provided to control the supply of used (contaminated) flushing fluid from the first filter unit. Optionally, a second filter outlet valve may be provided to control the discharge of a second filtered liquid from the second filter.

[0064] During operation, waste from the self-rinsing liquid filtration accumulates in the static filter bag formed in the second filtration unit. The liquid filtration system can be configured to periodically flush the second filter to remove the accumulated waste. The waste can be discharged to the system waste outlet or exported for further processing. A second filter waste valve can be provided to control the discharge of waste from the second filtration unit. A second filter inlet valve can be operated to close the second filter inlet. A second filter outlet valve can be operated to close the second filter outlet.

[0065] A liquid filtration system can be configured to introduce a packaging breakage fluid to disrupt (i.e., break up) the static filter bag. Waste trapped between individual filter elements and / or deposited in filter cells formed within the filter elements can be removed by the packaging breakage fluid. The packaging breakage fluid introduced into the second filter chamber can be a liquid or a gas. A second filter fluid control valve can be provided to control the introduction of the packaging breakage fluid. The packaging breakage fluid may contain air. A pump can be provided to pump the packaging breakage fluid through one or more fluid inlets. The one or more fluid inlets can be located in the lower portion of the second filter chamber. In one variation, the fluid can be drawn into the second filter chamber when flushing fluid is discharged from the second filter chamber.

[0066] Alternatively, or further, a mechanical agitation device may be provided to disturb the filter elements forming the static filter bag. The mechanical agitation device may include one or more movable members operable to disturb the filter elements forming the static filter bag. These one or more movable members may rotate or sweep within the second filter unit.

[0067] The second filter waste valve is operable to control the discharge of waste through the second filter waste outlet. Water and accumulated waste can be discharged from the second filter chamber to the waste disposal area.

[0068] In use, the second filter can be operated to concentrate the waste discharged from the first filter. The resulting waste discharged from the second filter may be, for example, sludge.

[0069] At least one electronic control unit may be configured to control the operation of one or more first filter valves and / or one or more second filter valves. The first electronic control unit includes one or more electronic controllers and a memory device. A set of calculation instructions may be stored on the memory device. When executed by the one or more electronic controllers, the calculation instructions may cause the at least one electronic control unit to control the liquid filtration system to operate according to the methods described herein. The calculation instructions may cause the at least one electronic control unit to selectively operate the liquid filtration system in a filtration mode and a rinsing mode.

[0070] The liquid may be water. In at least some embodiments, the liquid may be purified water, such as water containing or composed of potable (drinking) water. The water may be suitable for human consumption. Alternatively, the liquid may be wastewater, such as municipal or industrial wastewater.

[0071] One or more filter cells may each have a cross-sectional area ranging from 1 mm² to 10 mm² or from 1 mm² to 5 mm². One or more filter cells may each have a length greater than or equal to 6 mm, 8 mm, 10 mm, or 12 mm. One or more filter cells may each have a length less than 30 mm. One or more filter cells may each have an internal volume greater than 10 mm³, 20 mm³, 30 mm³, or 40 mm³. The filter element may have positive buoyancy, neutral buoyancy, or negative buoyancy in water. Each filter cell may be defined by one or more impermeable sidewalls.

[0072] According to another aspect of the invention, a liquid handling system is provided, which includes one or more of the liquid filtration systems described herein.

[0073] Liquid treatment systems can be configured to treat purified water, such as drinking (potable) water. A liquid treatment system may include one or more of the following: at least one storage tank, a screening system, a chemical treatment system, a sedimentation system, and a sterilization system. The chemical treatment system is configured to coagulate and / or flocculate the water, causing particles or solids in the water to coagulate. The sterilization system is configured to sterilize the water before distribution, such as for domestic (main) water supplies. One or more liquid filtration systems may be installed between the chemical treatment system and the sterilization system. A sedimentation system may be installed between the chemical treatment system and one or more liquid filtration systems. The liquid filtration system may be configured to discharge a second filtered liquid upstream of the first filtration unit. The second filtered liquid may be introduced upstream of the chemical treatment system. The second filtered liquid may be introduced upstream of both the chemical treatment system and the sedimentation system. The sterilization system may be located downstream of the liquid filtration system.

[0074] Within the scope of this application, it is expressly indicated that the various aspects, embodiments, examples, and alternatives listed in the foregoing paragraphs, claims, and / or the following description and drawings, particularly the various features therein, may be employed independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or by any combination of methods, unless these features are incompatible. The applicant reserves the right to amend any initially filed claim or accordingly file any new claim, including the right to amend any initially filed claim to reference and / or incorporate any feature of any other claim, even if the claim was not initially filed in this manner. Attached Figure Description

[0075] One or more embodiments of the present invention will be described by way of example only with reference to the accompanying drawings, wherein:

[0076] Figure 1 A schematic diagram of a liquid filtration system according to an embodiment of the present invention is shown;

[0077] Figure 2A A partial cross-sectional view of a filter for a liquid filtration system according to an embodiment of the present invention is shown;

[0078] Figure 2B An embodiment of the present invention is shown. Figure 2A The diagram shown illustrates the filter operating in filtration mode to filter drinking water.

[0079] Figure 2C Show Figure 4 A schematic diagram showing the filter operating in flushing mode to remove accumulated solid material;

[0080] Figure 3 Explanation shown Figure 1 The flowchart shown below illustrates the operation process of the liquid filtration system;

[0081] Figure 4 A schematic diagram of a liquid filtration system according to a further embodiment of the present invention is shown;

[0082] Figure 5 Explanation shown Figure 4 The flowchart shown below illustrates the operation process of the liquid filtration system;

[0083] Figure 6 A schematic diagram of a liquid treatment system including a liquid filtration system according to an embodiment of the present invention is shown;

[0084] Figure 7 Explanation shown Figure 6 The flowchart shown is a process flow diagram of the operation of the liquid handling system;

[0085] Figure 8 A schematic diagram of a liquid filtration system according to a further embodiment of the present invention is shown;

[0086] Figure 9 Explanation shown Figure 8 The flowchart shown below illustrates the operation process of the liquid filtration system;

[0087] Figure 10 A schematic diagram of a liquid filtration system according to a further embodiment of the present invention is shown;

[0088] Figure 11A A perspective view of the mechanical filter element of the second filter used in the liquid filtration system described herein is shown.

[0089] Figure 11B Show Figure 11A The end view of the mechanical filter element shown in the figure;

[0090] Figure 11C Show Figure 11A A perspective view of a variant of the mechanical filter element shown in the figure;

[0091] Figures 12A to 12E An example of a filter tank suitable for use in a liquid filtration system(s) according to the present invention is shown. Detailed Implementation

[0092] A liquid filtration system 1 and a liquid filtration process 100 according to one or more embodiments of the present invention will be described herein in conjunction with the accompanying drawings. The liquid filtration system 1 and the liquid filtration process 100 will be described herein in particular in connection with water filtration. However, it will be understood that the liquid filtration system 1 and the liquid filtration process 100 can be used to filter liquids other than water.

[0093] The liquid filtration system 1 according to the first embodiment of the present invention is in Figure 1 As shown in the figure. The liquid filtration system 1 in this embodiment of the present disclosure is configured to perform a filtration process and a flushing process. The filtration process includes or consists of mechanical filtration to remove waste from the water. The waste may include particles, aggregated particles, or other debris suspended in the water. The flushing process is performed to flush the filter to remove accumulated waste. The flushing process may be performed, for example, according to a predetermined schedule, or based on a determination that the liquid filtration system 1 is partially or completely blocked, for example, when the back pressure increases to exceed a threshold pressure.

[0094] like Figure 1As shown, the liquid filtration system 1 includes a filtration system inlet 3, a filtration system outlet 5, a filtration system waste outlet 7, a first filtration unit FT1, and a second filtration unit FT2. The first filtration unit FT1 is configured to filter unfiltered water supplied to the filtration system inlet 3. In use, the first filtration unit FT1 discharges a first filtered liquid (i.e., the initial filtrate); and the second filtration unit FT2 discharges a second filtered liquid (i.e., the second filtrate). It will be understood that the first filtered liquid and the second filtered liquid are typically the same liquid. For example, in this embodiment, both the first filtered liquid and the second filtered liquid contain water or are composed of water. As described herein, the first filter 11 and the second filter 31 are configured to filter waste containing solids or composed of solids from unfiltered water. The solids may include solid substances insoluble in the liquid and / or solid substances precipitated from the solution, or may consist of solid substances insoluble in the liquid and / or solid substances precipitated from the solution, such as in the form of precipitates. The first filtration unit FT1 discharges the first filtered liquid. In this embodiment, the first filtered liquid comprises or consists of filtered water. The first filtered liquid is discharged from the first filtration unit FT1 to the filtration system outlet 5.

[0095] The first filter unit FT1 includes a first filter 11. In this embodiment, the first filter 11 includes a first filter medium 13. The first filter medium 13 is disposed in the first filter chamber 15, such as... Figure 1As shown. The first filter chamber 15 has at least one first filter inlet 17, at least one first filter outlet 19, and at least one first filter waste outlet 21. The first filter medium 13 may have a closed structure excluding internal filter units. For example, the first filter medium 13 may contain particles, fine particles, or beads. Other types of filter media may be used in the first filter unit FT1. In this embodiment, the first filter medium 13 contains sand. In this embodiment, the first filter medium 13 forms a static filter bed SB1. Unfiltered (raw) water is passed through the static filter bed SB1. The first filter contains sand forming a sand bed SB1 in the first filter chamber 15. As water passes through the sand bed SB1, it is filtered. Waste suspended in the water is trapped in the cavities between the sand particles in the sand bed SB1. The filtered water from the first filter unit FT1 is discharged to at least one first filter outlet 19. Water is typically pumped under pressure through the sand bed SB1 by a water pump (not shown). Other types of filters may be considered for use in the first filter unit FT1. For example, the first filter unit FT1 may include one or more of the following: sand, activated carbon, composite media, or a particulate filter. The first filter media 13 may be omitted. For example, the first filter unit FT1 may include a settlement tank, in which waste is filtered by sedimentation. Alternatively, the first filter media 13 may include open-cell filter media of the type described herein.

[0096] The second filtration unit FT2 includes a second filter 31. The second filter 31 includes a second filter medium 33. The second filter medium 33 is disposed in the second filtration chamber 35. Figure 2A A partial cross-sectional view of a second filter unit FT2 according to an embodiment of this invention is shown (second filter media 33 omitted). The filter chamber 35 has at least one second filter inlet 37, at least one second filter outlet 39, and at least one second filter waste outlet 41. The at least one second filter waste outlet 41 may be separable from the at least one second filter inlet 37 and the at least one second filter outlet 39. Alternatively, the at least one second filter waste outlet 41 may be combined with one of the at least one second filter inlet 37 and the at least one second filter outlet 39. Figure 2B and Figure 2C In the schematic configuration shown, the at least one second filter waste outlet 41 is combined with the at least one second filter inlet 37. The second filter medium 33 is in the form of an open-cell filter medium 33. The second filter medium 33 includes a plurality of filter elements 43, each filter element 43 including one or more filter cells 45. Suitable open-cell filter media 33 are described in more detail herein. The second filter medium 33 forms a static filter pack FP1 in the second filter chamber 35, such as Figure 2BThe diagram is schematically shown. Water is filtered as it passes through the static filter pack FP1. Solids suspended in the water are deposited or settled in filter cells 45 formed in the second filter medium 33. Water can be pumped through the static filter pack FP1 under pressure. Alternatively, water can flow through the static filter pack FP1 by gravity. Water discharged from at least one first filter waste outlet 21 is introduced into the second filter unit FT2 through at least one second filter inlet 37. Water flows through the static filter pack FP1 to at least one second filter outlet 39. The static filter pack FP1 effectively filters the water supplied by the storage tank 11. Filtered water from the second filter unit FT2 is discharged to at least one second filter outlet 39. The filtered water can be discharged for further filtration, reuse, or discharge. As described herein, the second filter unit FT2 is cleaned periodically. Figure 2C The diagram illustrates the cleaning of the second filter unit FT2. Cleaning the second filter unit FT2 involves rinsing with liquid to remove accumulated waste. The accumulated waste is discharged from the second filter unit FT2 through at least one second filter waste outlet 41. The discharged waste may undergo further treatment, such as dehydration or drying.

[0097] One or more valves PFV-n are provided to control the flow through one or more of the first filter inlet 17, the first filter outlet 19, and the first filter waste outlet 21. The first filter inlet valve PFV-1 is associated with the first filter inlet 17. The first filter inlet valve PFV-1 opens to supply unfiltered (raw) water from the filtration system inlet 3 to the first filter chamber 15. The first filter outlet valve PFV-2 is associated with the first filter outlet 19. The first filter outlet valve PFV-2 opens to discharge filtered water from the first filter chamber 15 to the filtration system outlet 5. The first filter waste valve PFV-3 is associated with the first filter waste outlet 21. The first filter waste valve PFV-3 opens to discharge waste from the first filter chamber 15. An electronic control unit ECU1 is provided to control the operation of one or more first filter valves PFV-n. The electronic control unit ECU1 includes one or more electronic controllers EC1 and a memory device MD1. The electronic control unit ECU1 outputs control signals to control the first or each of the first filter valves PFV-n. In one variant, one or more first filter valves PFV-n may be manually controlled, for example, by the system operator.

[0098] Water filtered by the first filter unit FT1 is discharged to the filtration system outlet 5. As described herein, the first filter unit FT1 discharges the first filtered liquid (i.e., the initial filtrate). Waste filtered from the water by the first filter medium 13 is retained in the first filter unit FT1. In use, the first filter unit 11 separates the waste from the suspension. Accumulated waste may form a filter cake or sediment on the first filter unit 11. The accumulated waste includes retained particles and any other impurities present in the liquid or constitutes thereof. The first filter unit FT1 is periodically cleaned to remove at least some of the accumulated waste. In this embodiment, a rinsing method is performed to clean the first filter unit FT1. The rinsing method includes introducing a washing fluid into the first filter chamber 15 to displace the accumulated waste from the first filter medium 13. The washing fluid is introduced into the first filter chamber 15 through one or more washing inlets 23. One or more washing inlets 23 are disposed in the lower portion of the first filter chamber 15. A pump 25 is provided for pumping flushing fluid into the first filter chamber 15. The flushing fluid is introduced under pressure (i.e., at a pressure greater than atmospheric pressure) and disrupts or breaks up the sand bed SB1. The flushing fluid may contain a gas, such as air, or a liquid, such as water. In this embodiment, the flushing fluid is a flushing liquid. Liquid present in the first filter unit FT1 may be discharged from the first filter chamber 15, thereby flushing the first filter media 13 and carrying away accumulated waste from the first filter 11. Alternatively or additionally, a separate flushing fluid may be introduced into the first filter chamber 15 to flush the first filter media 13. The pump 25 is operable to pump flushing fluid into the first filter chamber 15 to flush the first filter unit FT1. Alternatively or additionally, the flow direction of the liquid may be reversed during the flushing process to flush the first filter unit FT1. The flushing fluid may contain a counter-flushing fluid that flows through the first filter 11 in the opposite direction.

[0099] The flushing fluid is preferably the same as (or compatible with) the liquid to be filtered supplied to the liquid filtration system 1. In this embodiment, the flushing fluid is water. The flushing fluid may contain unfiltered (raw) water (e.g., from the filtration system inlet 3) or filtered water (e.g., from downstream of the first filtration unit FT1). Alternatively, or additionally, the flushing fluid may be obtained from a different source. The flushing fluid is introduced into the first filtration chamber 15 and disrupts or breaks up the sand bed SB1. At least some of the accumulated waste is dispersed from the first filter media 13. The waste is suspended in the flushing fluid in the first filtration chamber 15. The used (contaminated) flushing fluid is then discharged through at least one first filter waste outlet 21. The waste suspended in the flushing fluid is thereby discharged from the first filtration chamber 15. The used (contaminated) flushing fluid is discharged to the second filtration unit FT2. At least some of the waste from the first filtration unit FT1 is flushed from the first filtration chamber 15 into the second filtration chamber 35.

[0100] The second filter unit FT2 is configured to filter the used (contaminated) flushing fluid discharged from the first filter unit FT1 during the flushing process. The second filter unit FT2 includes a second filter medium 33 disposed in a second filter chamber 35. The second filter chamber 35 has at least one second filter inlet 37, at least one second filter outlet 39, and at least one second filter waste outlet 41. The second filter medium 33 is in the form of an open-cell filter medium 33. The second filter medium 33 includes a plurality of filter elements 43, each filter element 43 comprising one or more filter cells 45. The open-cell filter medium 33 is described in more detail herein. The second filter medium 33 forms a static filter pack FP1 in the second filter chamber 35. The flushing fluid is filtered as it passes through the static filter pack FP1. Waste suspended in the flushing fluid deposits in the filter cells 45 formed in the second filter medium 33. The second filter 31 separates the waste from the suspension. The separated waste accumulates in the second filter 31. The accumulated waste contains retained particles and any other impurities in the flushing fluid, or is composed of them. Accumulated waste can form a filter cake or precipitate on the second filter medium 33. The flushing fluid can be pumped under pressure through the static filter pack FP1. Alternatively, the flushing fluid can flow through the static filter pack FP1 under gravity. The flushing fluid discharged from at least one first filter waste outlet 21 is introduced into the second filter unit FT2 through at least one second filter inlet 37. The flushing fluid flows through the static filter pack FP1 to at least one second filter outlet 39. The static filter pack FP1 effectively filters the flushing fluid supplied from the first filter unit FT1. The second filter unit FT2 discharges a second filtered liquid. In this embodiment, the second filtered liquid comprises or consists of the filtered flushing fluid. The second filtered liquid is discharged from the second filter chamber 35 to at least one second filter outlet 39. In this embodiment, the second filtered liquid is discharged for further filtration. The liquid filtration system 1 includes a supply line 47 connected to at least one second filter outlet 39. The supply line 47 is configured to introduce the second filtered liquid into the first filter unit FT1. The supply line 47 introduces the second filtered liquid upstream of the first filter chamber 15. The second filtered liquid is therefore recycled in the liquid filtration system 1 instead of being discharged into the waste. The second filtered liquid is mixed with unfiltered (raw) water introduced at a filtration system inlet 3. In a variant, the second filtered liquid can be introduced directly into the first filtration chamber 15. The second filtered liquid can then be mixed with the unfiltered (raw) water in the first filtration chamber 15. A one-way valve (not shown) may be provided in the supply line 47 to reduce or prevent unfiltered (raw) water from bypassing the first filtration unit FT1.

[0101] One or more valves SFV-n are provided to control the flow through one or more of the second filter inlet 37, the second filter outlet 39, and the second filter waste outlet 41. The second filter inlet valve SFV-1 is associated with the second filter inlet 37. The second filter inlet valve SFV-1 is opened to supply flushing fluid discharged from the first filter chamber 15 to the second filter chamber 35. The second filter outlet valve SFV-2 is associated with the second filter outlet 39. The second filter outlet valve SFV-2 is opened to discharge filtered water from the second filter chamber 35 to the filtration system outlet 5. The second filter waste valve SFV-3 is associated with the second filter waste outlet 41. The second filter waste valve SFV-3 is opened to discharge waste from the second filter chamber 35. An electronic control unit ECU1 is provided to control the operation of one or more second filter valves SFV-n. The electronic control unit ECU1 outputs control signals to control the one or more first filter valves SFV-n. It should be understood that two or more electronic control units may be provided to control the primary valve PFV-n and the secondary valves SFV-n. In one variant, one or more second filter valves SFV-n can be manually controlled, for example, by the system operator.

[0102] Waste filtered by the self-rinsing fluid accumulates in the static filter pack FP1 formed in the second filter chamber 35. The second filter unit FT2 is periodically flushed to discharge the accumulated waste to the filter system waste outlet 7. The second filter inlet valve SFV-1 is operated to close the second filter inlet 37; and the second filter outlet valve SFV-2 is operated to close the second filter outlet 39. Pack disruption fluid is introduced into the second filter chamber 35 to disrupt (i.e., break up) the static filter pack FP1. Waste trapped between individual filter elements 43 and / or deposited in the filter cells 45 formed in the filter elements is removed. The pack disruption fluid introduced into the second filter chamber 35 can be a liquid or a gas. A second filter fluid control valve SFV-4 is provided to control the introduction of the pack disruption fluid. In this embodiment, the pack disruption fluid is air. An air pump 51 is provided to pump air through one or more fluid inlets 53 located in the lower portion of the second filter chamber 35. Operate the second filter waste valve SFV-3 to open the second filter waste outlet 41. Water and accumulated waste are thus discharged from the second filter chamber 35 to the waste disposal area. The second filter unit FT2 effectively concentrates the waste discharged from the first filter unit FT1. The resulting waste discharged from the second filter unit FT2 contains sludge. In one variation, fluid may be drawn into the second filter chamber 35 when the flushing fluid is discharged. Alternatively, or additionally, a mechanical disruptor may be provided to agitate the filter elements 43 forming the static filter pack FP1. The mechanical disruptor may, for example, include one or more movable members operable to displace the filter elements 43 forming the static filter pack FP1. These one or more movable members may rotate or sweep within the second filter chamber 35.

[0103] Please refer to the following: Figure 3 The first flowchart FD1 shown illustrates a water filtration method 100 according to an embodiment of the present invention. In the liquid filtration system 1, water is received as influent (block 105). The liquid filtration system 1 operates selectively in a filtration mode and a flushing mode. In the filtration mode, unfiltered (raw) water is supplied to the first filtration unit FT1 (block 110). The unfiltered (raw) water may, for example, contain particles or other debris remaining in a suspended state. Particles may aggregate to form larger clumps or flocs, which may also be suspended in the unfiltered (raw) water. The first filter 11 mechanically filters the unfiltered (raw) water to remove waste materials remaining in a suspended state (block 115). The first filtered water (filtrate) is discharged from the first filtration unit FT1 to one or more filtration system outlets 5 (block 120).

[0104] The liquid filtration system 1 periodically switches to a flushing mode to clean the first filter unit FT1 (block 125). In this flushing mode, the first filter unit FT1 is cleaned by introducing flushing fluid (block 130). The flushing fluid removes waste material accumulated in the first filter unit FT1. In this embodiment, the flushing fluid is water. At least some waste material remains suspended in the flushing fluid. The flushing fluid and suspended waste material are discharged from the first filter unit FT1 to the second filter unit FT2 (block 135). The second filter unit FT2 is operated to filter the flushing fluid to remove suspended waste material (block 140). The second filtered liquid, containing or composed of the second filtered liquid, is discharged from the second filter unit FT2 (block 145). At least some of the second filtered liquid is recycled (block 150). In this embodiment, the second filtered liquid system is recycled by returning at least some of the liquid to the upstream of the liquid filtration system 1.

[0105] The second filter unit FT2 (block 155) is cleaned periodically. Cleaning of the second filter unit FT2 in this embodiment is performed when the liquid filtration system 1 is operating in flushing mode. However, it should be understood that the second filter unit FT2 can also be cleaned when the liquid filtration system 1 is operating in filtration mode. For example, the liquid filtration system 1 can switch from flushing mode to filtration mode before or during cleaning of the second filter unit FT2. The second filter unit FT2 is cleaned by introducing a fluid such as air to disrupt the static filter assembly FP1 (block 160). Accumulated solid waste is removed from the static filter assembly FP1. Water and waste are discharged from the second filter unit FT2 to the filtration system waste outlet 7 (block 165). For example, the second filter waste outlet 41 can be opened to discharge water and accumulated waste, thereby flushing the second filter unit FT2. The material discharged from the second filter unit FT2 is typically in the form of concentrated sludge. The water filtration method continues to switch between filtration mode and flushing mode as needed.

[0106] In at least some embodiments, the second filter unit FT2 reduces water consumption of the liquid filtration system 1. The second filter unit FT2 enables the recycling of at least some of the flushing fluid for cleaning the first filter unit FT1. The waste discharged from the second filter unit FT2 is concentrated. The accumulated waste can be disposed of in a conventional manner or may undergo further treatment, such as drying to reduce its water content.

[0107] Now refer to Figure 4 and Figure 5 A liquid filtration system 1 and a liquid filtration method 300 according to a further embodiment of the present invention will be described. The liquid filtration system 1 and the liquid filtration method 300 are the references to the above. Figure 1 Figure 2 and Figure 3 Variations of the described embodiments. The same reference numerals are used for the same features.

[0108] The operation of the first filtration unit FT1 is the same as in the above embodiment. A first filtered liquid (i.e., initial filtrate) is discharged from the first filter 11 to the filtration system outlet 5. At least some accumulated waste is discharged by performing flushing to periodically clean the first filter 11. Flushing liquid is introduced into the first filtration chamber 15. The flushing liquid is discharged through at least one first filtration waste outlet 21, thereby transporting at least some accumulated waste out of the first filtration chamber 15. The flushing liquid is discharged to the second filtration unit FT2. The second filter 31 is configured to filter the flushing liquid. As described herein, the second filter 31 comprises a second filter medium 33 in the form of an open-pore filter medium. The second filter 31 filters the flushing liquid and discharges a second filtered liquid (i.e., the second filtrate).

[0109] The liquid filtration system 1 and liquid filtration method 100 in the above embodiments return a second filtered liquid from the second filtration unit FT2 to the first filtration unit FT1 for filtration. The second filtered liquid includes or consists of filtered flushing liquid discharged from the second filtration unit FT2. In this embodiment, the second filtered liquid is discharged from the second filtration unit FT2 to one or more filtration system outlets 5. In at least some embodiments, it has been determined that the second filtration unit FT2 provides sufficient filtration to allow the second filtered liquid to be discharged from the liquid filtration system 1. The second filtered liquid may be mixed with the first filtered liquid discharged from the first filtration unit FT1. The supply line 47 may be omitted in this configuration. Alternatively, a flow control valve (not shown) may be selectively provided to supply the second filtered liquid to the first filtration unit FT1 or one or more filtration system outlets 5.

[0110] Please refer to the following: Figure 5 The second flowchart FD2 shown illustrates a liquid filtration method 200 according to an embodiment of the present invention. Clean water is received as influent in a liquid filtration system 1 (block 205). The liquid filtration system 1 operates selectively in a filtration mode and a flushing mode. In the filtration mode, unfiltered (raw) water is supplied to a first filtration unit FT1 (block 210). The unfiltered (raw) water may, for example, contain particles or other debris remaining in suspension. Particles may aggregate to form larger clumps or flocs, which may also be suspended in the unfiltered (raw) water. The first filter 11 mechanically filters the unfiltered (raw) water to remove waste materials remaining in suspension (block 215). The resulting filtered water (filtrate) is discharged from the first filtration unit FT1 as the first filtered liquid to one or more filtration system outlets 5 (block 220).

[0111] The liquid filtration system 1 periodically switches to a flushing mode to clean the first filter unit FT1 (block 225). The switching from filtration mode to flushing mode can be performed, for example, according to a predetermined (time) schedule or based on pressure changes across the first filter. In this flushing mode, the first filter 11 (block 230) is cleaned by introducing a flushing fluid. The flushing fluid removes waste material accumulated in the first filter unit FT1. At least some of the waste material remains suspended in the flushing fluid. The flushing fluid and the suspended waste material are discharged from the first filter unit FT1 to the second filter unit FT2 (block 235). The second filter unit FT2 filters the flushing fluid to remove at least some of the suspended waste material (block 240). The filtered flushing fluid is discharged from the second filter unit FT2 as a second filtered liquid (block 245). In this embodiment, at least some of the second filtered liquid is discharged to the filtration system outlet 5 (block 250).

[0112] The second filter unit FT2 (block 255) is cleaned periodically. Cleaning of the second filter unit FT2 in this embodiment is performed when the liquid filtration system 1 is operating in flushing mode. However, it should be understood that the second filter unit FT2 can also be cleaned when the liquid filtration system 1 is operating in filtration mode. For example, the liquid filtration system 1 can switch from flushing mode to filtration mode before or during cleaning of the second filter unit FT2. The second filter unit FT2 is cleaned by introducing a fluid such as air to break down the static filter pack FP1 (block 260). Accumulated solid waste is removed from the static filter pack FP1. Waste is discharged from the second filter unit FT2 to the filtration system waste outlet 7 (block 265). For example, the second filter waste outlet 41 can be opened to discharge water and accumulated waste, thereby flushing the second filter unit FT2. The material discharged from the second filter unit FT2 is typically in the form of concentrated sludge. The water filtration method continues to switch between filtration mode and flushing mode as needed.

[0113] The liquid filtration system 1 in the above embodiments is described with reference to a first filtration unit FT1 comprising a sand bed filter. Other types of first filtration units FT1 for the liquid filtration system 1 are considered. For example, the first filtration unit FT1 may comprise or consist of a biological filter. The biological filter may be cleaned periodically in a flushing method comprising introducing flushing fluid. The biological filter can be cleaned periodically by flushing. Flushing fluid may be introduced into the biological filter for cleaning. A second filtration unit FT2 may be provided according to the methods described herein to filter at least some of the flushing fluid for cleaning the biological filter. Alternatively, the first filtration unit FT1 may comprise a drum filter or a screen filter. The first filtration unit FT1 may provide a continuous or substantially continuous supply of wastewater to the second filtration unit FT2. A balancing tank 49 may optionally be provided in the liquid filtration system 1. The balancing tank 49 is located in… Figure 4The equalization tank 49, indicated by a dashed line, is located between the first filter unit FT1 and the second filter unit FT2. The equalization tank 49 is suitable for batch processing systems. The second filter unit FT2 is suitable for use with other types of first filter units FT1 that are cleaned by rinsing. The first filter unit FT1 may comprise a static filter bag FP1 consisting of a plurality of perforated filter elements 43 of the type described herein. The liquid filtration system 1 may comprise a first filter 11 and a second filter 31 of the same type. The first filter unit FT1 may be periodically rinsed with rinsing fluid. The rinsing fluid may be discharged into and filtered in the second filter unit FT2. The first filter 11 and the second filter 31 may have different volumes. For example, the first filter unit FT1 may comprise a first static filter bag FP1 having a first volume, and the second filter unit FT2 may comprise a second static filter bag FP1 having a second volume. The first volume may be larger or smaller than the second volume.

[0114] Figure 6 A liquid processing system 500 for processing liquids is shown. The liquid processing system 500 may be, for example, in the form of a liquid processing plant or liquid processing facility. The liquid processing system 500 includes a liquid filtration system 1 according to an embodiment of the present invention. A liquid processing method 600 for processing liquids is shown. Figure 7 According to one embodiment of the present invention, liquid treatment method 600 includes liquid filtration method 100. As described herein, liquid filtration system 1 and liquid filtration method 100 may be used independently of liquid treatment system 500 and liquid treatment method 600 described herein.

[0115] In this embodiment, the liquid treatment system 500 and the liquid treatment method 600 are assembled to treat water. The liquid treatment system 500 may be referred to as a water treatment system 500; and the liquid treatment method 100 may be referred to as a water treatment method 100. The water may be wastewater, such as municipal wastewater or industrial wastewater. The liquid treatment system 500 may be referred to as a wastewater treatment system 500; and the liquid treatment method 100 may be referred to as a wastewater treatment method 100. In this embodiment of the invention, the liquid treatment system 500 and the liquid treatment method 600 are suitable for treating purified water. The term "purified water" is used herein to refer to water that is harmless to humans. Purified water may include or consist of drinking water (potable) and / or domestic water. The liquid treatment system 500 may be referred to as a purified water treatment system 500; and the liquid treatment method 100 may be referred to as a purified water treatment method 100. The liquid treatment system 500 and the liquid treatment method 600 for treating water will now be described.

[0116] A schematic diagram of the liquid handling system 500 is shown below. Figure 6The liquid treatment system 500 includes one or more system inlets 510; one or more system outlets 520; and one or more system waste outlets 530. System inlets 510 are configured to receive incoming water for treatment. Water introduced through system inlets 510 is treated as it is conveyed through the liquid treatment system 500. To help distinguish it from water within the liquid treatment system 500, the water received at system inlets 510 is referred to as untreated (raw or unfiltered) water. System outlets 520 are configured to discharge water treated by the liquid treatment system 500. Water discharged at system outlets 520 is referred to herein as treated water. It should be understood that treated water discharged from system outlets 520 may undergo additional treatment or filtration downstream of the liquid treatment system 500. System waste outlets 530 discharge waste removed from the water. Waste discharged from the liquid treatment system 500 through system waste outlets 530 may undergo further treatment. For example, the discharged waste may undergo a drying process or dewatering to reduce its water content.

[0117] The liquid treatment system 500 includes at least one storage tank 540, a screening system 550, a chemical treatment system 560, a sedimentation system 570, and a sterilization system 580. A liquid filtration system 1 is disposed between the sedimentation system 570 and the sterilization system 580. At least one storage tank 540 is configured to store water introduced at the system inlet 510. The storage tank or each storage tank 540 may include one or more of the following: storage container, tank, lagoon, or reservoir. Other types of storage tanks 540 are also included. The screening system 550 is configured to perform preliminary screening to remove debris, such as solids or leaves. The chemical treatment system 560 is configured to coagulate and / or flocculate the water, causing particles or solids in the water to agglomerate. The chemical treatment system 560 may, for example, include one or more chemical dosing systems for introducing a flocculant; and / or one or more electrocoagulation units. The sedimentation system 570 may include one or more settling tanks to promote the sedimentation of solids in the water. Water is supplied to the liquid filtration system 1 described herein from a sedimentation system 570. Water discharged from the sedimentation system 570 is introduced into the filtration system inlet 3. The liquid filtration system 1 is cleaned using purified water, as described herein. At least some of the purified water is filtered and returned for treatment in the liquid treatment system 500. Purified water is thus recycled within the liquid treatment system 500. The recycled water is returned upstream of the liquid filtration system 1, for example. In particular, the recycled water is introduced between the screening system 550 and the chemical treatment system 560. The liquid filtered by the liquid filtration system 1 is output to a sterilization system 580 capable of sterilizing the water. The sterilized water is discharged from the sterilization system 580 to one or more system outlets 520. The treated water is output for distribution. The one or more system outlets 520 may, for example, be connected to a main water supply unit. The liquid treatment system 500 may include one or more pumps (not shown) for pumping water.

[0118] Liquid handling method 600 Figure 7 The third-party block diagram FD3 is illustrated. Liquid filtration method 100 is performed within liquid treatment method 600. Liquid treatment method 600 includes storing untreated liquid in one or more storage tanks (block 605). Water is screened to remove debris (block 610). The water then undergoes chemical treatment (block 615). This chemical treatment may include, for example, coagulation and / or flocculation treatment or consist thereof. The treated water is introduced into a settling tank to promote the sedimentation of debris (block 620). After sedimentation, the water is filtered (block 625). This filtration corresponds to the first liquid filtration method 100 or the second liquid filtration method 200 described herein. Liquid filtration methods 100 and 200 include cleaning the filtration equipment using a flushing solution or a rinsing fluid. The flushing solution may be, for example, a rinsing fluid. The rinsing solution is filtered and a portion of the second filtered liquid is returned for further treatment. As described herein, at least some of the rinsing solution may be recycled. The filtered water is then sterilized (block 630). The sterilized water is then discharged as potable water (block 635). Subsequently, the potable water is discharged, for example, as part of a tap water system.

[0119] Now refer to Figure 8 and Figure 9 A liquid filtration system 1 and a liquid filtration method 300 according to a further embodiment of the present invention will be described. The liquid filtration system 1 and the liquid filtration method 300 are the references to the above. Figure 1 Figure 2 and Figure 3 Variations of the described embodiments. The same reference numerals are used for the same features.

[0120] The liquid filtration system 1 and liquid filtration method 300 in this embodiment are configured to filter wastewater. The wastewater may be municipal wastewater or industrial wastewater. The filtration method includes or is composed of mechanical filtration to remove waste from the wastewater. The waste may include particles suspended in the water, agglomerated particles, or other debris.

[0121] like Figure 8As shown, the liquid filtration system 1 includes a filtration system inlet 3, a filtration system outlet 5, a filtration system waste outlet 7, a first filtration unit FT1, and a second filtration unit FT2. The first filtration unit FT1 is configured to filter unfiltered water supplied to the filtration system inlet 3. The unfiltered water contains waste. The waste may contain solids or impurities suspended in the unfiltered water. The first filtration unit FT1 is configured to separate (i.e., remove) this waste from the suspension in the unfiltered water. The waste separated from the water accumulates in the first filtration unit FT1. The accumulated waste contains retained particles and any other impurities present in the water or composed of them. The accumulated waste may form a filter cake or sediment on the first filter 11. In use, the first filtration unit FT1 discharges a first filtered liquid (i.e., the initial filtrate); and the second filtration unit FT2 discharges a second filtered liquid (i.e., the second filtrate). As described herein, the first filter 11 and the second filter 31 are configured to filter waste containing solids or composed of solids from unfiltered water. The solid may comprise, or be composed of, solid substances insoluble in liquid and / or solid substances precipitated from solution, such solid substances being, for example, in the form of a precipitate. In this embodiment, the first filtered liquid and the second filtered liquid comprise or consist of filtered water. The first filtered liquid is discharged from the first filtration unit FT1 to the filtration system outlet 5. The second filtered liquid discharged from the second filtration unit FT2 may also be discharged to the filtration system outlet 5.

[0122] In this embodiment, the first filter unit FT1 is a drum filter. The first filter unit FT1 includes a first filter 11. The first filter 11 includes a screen filter 55. In this configuration, the screen filter 55 is cylindrical and forms a first filter chamber 15, such as... Figure 8As shown. The first filter unit FT1 has at least one first filter inlet 17, at least one first filter outlet 19, and at least one first filter waste outlet 21. The screen filter 55 is configured to rotate about a central longitudinal axis. Wastewater is pumped into the first filter chamber 15. First filtered water (i.e., initial filtrate) passes through the screen filter 55 and exits through the first filter outlet 19. The area of ​​the screen filter 55, positioned at a lower position, effectively filters the wastewater. The first filtered water is discharged to the filtration system outlet 5. Waste is retained in the first filter chamber 15. When the first filter unit FT1 becomes clogged, a flushing liquid is supplied under pressure to flush the screen filter 55. The flushing liquid is delivered as a high-pressure jet to remove or break down the waste. The screen filter flushing liquid may be applied to the interior of the screen 55. Alternatively or additionally, the flushing liquid may be applied to the exterior of the screen filter 55. When the flushing liquid is supplied, the screen filter 55 is rotated, for example, by 90° or 180°. The flushing liquid thereby impacts local sectors of the screen filter 55. Rotation of the screen filter 55 moves the cleaning sector to the lower portion to filter the wastewater supplied to the first filtration unit FT1. Rinse fluid is typically supplied periodically, for example, during the cleaning process. The cleaning process may be initiated depending on whether the screen filter 55 is clogged or exceeds normal operating conditions. The cleaning process may be performed continuously or substantially continuously, for example, if the first filtration unit FT1 is operating at full capacity. The rinsing fluid and any accumulated waste are discharged from the first filtration chamber 15 through the first filter waste outlet 21. The used (contaminated) rinsing fluid is discharged from the first filtration unit FT1 to the second filtration unit FT2.

[0123] The second filter unit FT2 includes a second filter 31. The second filter 31 includes a second filter medium 33. The second filter medium 33 is disposed in the second filter chamber 35. The second filter unit FT2 is the same as that referred to herein. Figure 2A , Figure 2B and Figure 2C The configuration described is the same. The filter chamber 35 has at least one second filter inlet 37, at least one second filter outlet 39, and at least one second filter waste outlet 41. The at least one second filter waste outlet 41 may be separable from the at least one second filter inlet 37 and the at least one second filter outlet 39. Alternatively, the at least one second filter waste outlet 41 may be combined with one of the at least one second filter inlet 37 and the at least one second filter outlet 39. Figure 2B and Figure 2CIn the schematically illustrated configuration, the at least one second filter waste outlet 41 is combined with the at least one second filter inlet 37. The second filter medium 33 is in the form of an open-cell filter medium 33. The second filter medium 33 includes a plurality of filter elements 43, each filter element 43 including one or more filter cells 45. The open-cell filter medium 33 is described in more detail herein. The second filter medium 33 forms a static filter pack FP1 in the second filter chamber 35, as shown below. Figure 2B The diagram is schematically shown. Water is filtered as it passes through the static filter pack FP1. Solids suspended in the water deposit or settle in filter cells 45 formed in the second filter medium 33. The second filter unit FT2 separates the waste from the suspension. The separated waste accumulates in the second filter unit FT2. The accumulated waste contains or consists of retained particles and any other impurities in the rinsing liquid. The accumulated waste may form a filter cake or sediment on the second filter medium 33. Water may be pumped through the static filter pack FP1 under pressure. Alternatively, water may flow through the static filter pack FP1 by gravity. Water discharged from at least one first filter waste outlet 21 is introduced into the second filter unit FT2 through at least one second filter inlet 37. Water flows through the static filter pack FP1 to at least one second filter outlet 39. The static filter pack FP1 effectively filters the water supplied by the storage tank 11. Filtered water discharged from the second filter unit FT2 is discharged to at least one second filter outlet 39 as filtered water. The filtered water can be discharged for further filtration, reuse, or discharge. The second filter unit, FT2, should be cleaned periodically as described in this article. Figure 2C The diagram illustrates the cleaning of the second filter unit FT2. Cleaning the second filter unit FT2 involves rinsing with liquid to remove accumulated waste. The accumulated waste is discharged from the second filter unit FT2 through at least one second filter waste outlet 41. The discharged waste may undergo further treatment, such as dehydration or drying.

[0124] As described herein, the first filtration unit FT1 discharges a first filtered liquid (i.e., initial filtrate). The first filtered liquid comprises or consists of wastewater filtered by the first filtration unit FT1. The first filtered liquid is discharged from the first filtration unit FT1 to the filtration system outlet 5. Waste filtered from the water by the first filter medium 13 is retained in the first filtration unit FT1. The first filtration unit FT1 is cleaned to remove accumulated waste. In this embodiment, the rinsing method is performed simultaneously with the filtration of wastewater by the first filtration unit FT1. The rinsing method includes introducing rinsing fluid into the first filtration chamber 15 to displace the waste. The rinsing fluid is introduced into the first filtration chamber 15 through one or more cleaning inlets 23. A pump 25 is provided for pumping the rinsing fluid into the first filtration chamber 15. The rinsing fluid may optionally be introduced under pressure (i.e., at a pressure greater than atmospheric pressure) to break down or decompose the accumulated waste. The rinsing fluid may comprise a gas, such as air; or a liquid, such as water. In this embodiment, the rinsing fluid is a rinsing liquid. The flushing fluid is preferably the same as (or compatible with) the liquid to be filtered supplied to the liquid filtration system 1. In this embodiment, the flushing fluid is in the form of water. The flushing fluid may contain unfiltered (raw) water (e.g., from the filtration system inlet 3) or filtered water (e.g., from downstream of the first filtration unit FT1). Alternatively, or additionally, the flushing fluid may be obtained from a different source. The flushing fluid is introduced into the first filtration chamber 15 and the accumulated waste, and the purified water, typically in the form of sludge, is discharged from the first filtration chamber 15 through the first filtration waste outlet 21. The accumulated waste is thereby discharged from the first filtration chamber 15. At least some of the accumulated waste may be flushed from the first filtration chamber 15 into the second filtration chamber 35.

[0125] The second filter unit FT2 is configured to filter the flushing fluid discharged from the first filter unit FT1 during the cleaning process. The second filter unit FT2 includes a second filter medium 33 disposed in a second filter chamber 35. The second filter chamber 35 has at least one second filter inlet 37, at least one second filter outlet 39, and at least one second filter waste outlet 41. The second filter medium 33 is in the form of an open-cell filter medium 33. The second filter medium 33 includes a plurality of filter elements 43, each filter element 43 including one or more filter cells 45. The open-cell filter medium 33 is described in more detail herein. The second filter medium 33 forms a static filter pack FP1 in the second filter chamber 35. The flushing fluid is filtered as it passes through the static filter pack FP1. Waste suspended in the flushing fluid is deposited in the filter cells 45 formed in the second filter medium 33. The flushing fluid can be pumped under pressure through the static filter pack FP1. Alternatively, the flushing fluid can flow through the static filter pack FP1 by gravity. The flushing liquid discharged from at least one first filter waste outlet 21 is introduced into the second filter unit FT2 through at least one second filter inlet 37. The flushing liquid flows through a static filter pack FP1 to at least one second filter outlet 39. The static filter pack FP1 effectively filters the flushing liquid supplied from the first filter unit FT1. The second filter unit FT2 discharges a second filtered liquid. In this embodiment, the second filtered liquid comprises or is composed of the filtered flushing liquid. The second filtered liquid is discharged from the second filter chamber 35 to at least one second filter outlet 39. In this embodiment, the second filtered liquid may be discharged for further filtration or may be recycled through the first filter unit FT1 (by...). Figure 8 (The dashed line in the figure indicates) or is used as flushing fluid for the first filtration unit FT1. The liquid filtration system 1 includes a supply line 47 connected to at least one second filter outlet 39. The supply line 47 is configured to introduce the second filtered liquid into the first filtration unit FT1. The supply line 47 can be configured to introduce the second filtered liquid upstream of the first filtration unit FT1. The second filtered liquid is thus recycled in the liquid filtration system 1 instead of being discharged to waste. The second filtered liquid is mixed with unfiltered (raw) water introduced at a filtration system inlet 3. In a variant, the second filtered liquid can be introduced directly into the first filtration chamber 15. The second filtered liquid can be mixed with the unfiltered (raw) water in the first filtration chamber 15. A one-way valve (not shown) may be provided in the supply line 47 to reduce or prevent unfiltered (raw) water from bypassing the first filtration unit FT1.

[0126] Waste filtered by the self-rinsing fluid accumulates in the static filter pack FP1 formed in the second filter chamber 35. The second filter unit FT2 is periodically flushed to discharge the accumulated waste to the filter system waste outlet 7. The second filter inlet valve SFV-1 is operated to close the second filter inlet 37; and the second filter outlet valve SFV-2 is operated to close the second filter outlet 39. Pack disruption fluid is introduced into the second filter chamber 35 to disrupt (i.e., break up) the static filter pack FP1. Waste trapped between individual filter elements 43 and / or deposited in the filter cells 45 formed in the filter elements is removed. The pack disruption fluid introduced into the second filter chamber 35 can be a liquid or a gas. A second filter fluid control valve SFV-4 is provided to control the introduction of the pack disruption fluid. In this embodiment, the pack disruption fluid is air. An air pump 51 is provided to pump air through one or more fluid inlets 53 located in the lower portion of the second filter chamber 35. Operate the second filter waste valve SFV-3 to open the second filter waste outlet 41. Water and accumulated waste are thus discharged from the second filter chamber 35 to the waste disposal area. The second filter unit FT2 effectively concentrates the waste discharged from the first filter unit FT1. The resulting waste discharged from the second filter unit FT2 contains sludge. In one variation, fluid may be drawn into the second filter chamber 35 when the flushing fluid is discharged. Alternatively, or additionally, a mechanical disruptor may be provided to agitate the filter elements 43 forming the static filter pack FP1. The mechanical disruptor may, for example, include one or more movable members operable to displace the filter elements 43 forming the static filter pack FP1. These one or more movable members may rotate or sweep within the second filter chamber 35.

[0127] Now refer to Figure 9 The fourth flowchart FD4 shown illustrates a liquid filtration method 300 according to an embodiment of the present invention. The liquid filtration method 300 in this embodiment is a wastewater filtration method 300. Wastewater is received as influent in the liquid filtration system 1 (block 305). The liquid filtration method 300 includes simultaneous filtration and cleaning methods. Unfiltered (raw) wastewater is supplied to a first filtration unit FT1 (block 310). The unfiltered (raw) water may, for example, contain particles or other debris remaining in suspension. Particles may aggregate to form larger clumps or flocs, which may also be suspended in the unfiltered (raw) water. A first filter 11 mechanically filters the unfiltered (raw) water to remove waste (block 315). The first filtered water (filtrate) is discharged from the first filtration unit FT1 to one or more filtration system outlets 5 (block 320).

[0128] A flushing solution is supplied to flush the first filter unit FT1 (block 325). The first filter unit FT1 is cleaned by the flushing solution (block 330). The flushing solution removes waste material accumulated in the first filter unit FT1. In this embodiment, the flushing solution is water. At least some waste material remains suspended in the flushing solution. The flushing solution and suspended waste material are discharged from the first filter unit FT1 to the second filter unit FT2 (block 335). The second filter unit FT2 can be used to filter the flushing solution to remove suspended waste material (block 340). A second filtered liquid containing or composed of the second filtered liquid is discharged from the second filter unit FT2 (block 345). At least some of the second filtered liquid is recyclable (block 350).

[0129] The second filter unit FT2 (block 355) is cleaned periodically. Cleaning of the second filter unit FT2 in this embodiment is performed when the liquid filtration system 1 is operating in flushing mode. However, it should be understood that the second filter unit FT2 can also be cleaned when the liquid filtration system 1 is operating in filtration mode. For example, the liquid filtration system 1 can switch from flushing mode to filtration mode before or during cleaning of the second filter unit FT2. The second filter unit FT2 is cleaned by introducing fluid (such as air) to break down the static filter pack FP1 (block 360). Accumulated solid waste is removed from the static filter pack FP1. Water and waste are discharged from the second filter unit FT2 to the filtration system waste outlet 7 (block 365). For example, the second filter waste outlet 41 can be opened to discharge water and accumulated waste, thereby flushing the second filter unit FT2. The material discharged from the second filter unit FT2 is typically in the form of concentrated sludge. The water filtration method continues to switch between filtration mode and flushing mode as needed.

[0130] Now refer to Figure 10 A liquid filtration system 1 according to a further embodiment of the present invention will be described. This liquid filtration system 1 is the one described above. Figure 3 , Figure 4 and Figure 5 Variations of the described embodiments. The same reference numerals are used for the same features.

[0131] The first filter unit FT1 includes a first filter 11. In this embodiment, the first filter 11 includes a first filter medium 13. The first filter medium 13 is disposed in the first filter chamber 15, such as... Figure 10As shown in the diagram. The first filter chamber 15 has at least one first filter inlet 17, at least one first filter outlet 19, and at least one first filter waste outlet 21. The first filter medium 13 is in the form of an open-cell filter medium 13. The first filter medium 13 includes a plurality of filter elements 43, each filter element 43 including one or more filter cells 45. A suitable open-cell filter medium 13 is the filter medium 33 described herein with reference to the second filter unit FT2. The first filter medium 13 forms a first static filter pack FP1 (corresponding to) in the first filter chamber 15. Figure 2B (The configuration shown in the diagram). Water is filtered as it passes through the first static filter pack FP1.

[0132] The second filter unit FT2 includes a second filter 31. The second filter 31 includes a second filter medium 33. The second filter medium 33 is disposed in a second filter chamber 35. The filter chamber 35 has at least one second filter inlet 37, at least one second filter outlet 39, and at least one second filter waste outlet 41. The at least one second filter waste outlet 41 may be separate from the at least one second filter inlet 37 and the at least one second filter outlet 39. Alternatively, the at least one second filter waste outlet 41 may be combined with one of the at least one second filter inlet 37 and the at least one second filter outlet 39. The second filter medium 33 is in the form of an open-cell filter medium 33. The second filter medium 33 includes a plurality of filter elements 43, each filter element 43 including one or more filter cells 45. Suitable open-cell filter media 33 are described in more detail herein. The second filter medium 33 forms a second static filter pack FP2 in the second filter chamber 35, such as Figure 4 B is schematically shown. Water is filtered as it passes through the static filter pack FP1. Solids suspended in the water are deposited or settled in filter cells 45 formed in the second filter medium 33. Water can be pumped through the static filter pack FP2 under pressure. Alternatively, water can flow through the static filter pack FP2 by gravity. Water discharged from at least one first filter waste outlet 21 is introduced into the second filter unit FT2 through at least one second filter inlet 37. Water flows through the static filter pack FP2 to at least one second filter outlet 39. The static filter pack FP2 effectively filters water supplied from the storage tank 11. Filtered water from the second filter unit FT2 is discharged to at least one second filter outlet 39 as filtered water. The filtered water can be discharged for further filtration, reuse, or discharge. As described herein, the second filter unit FT2 is cleaned periodically. Figure 4 Figure C shows a schematic diagram of cleaning the second filter unit FT2. Cleaning the second filter unit FT2 involves rinsing with liquid to remove accumulated waste. The accumulated waste is discharged from the second filter unit FT2 through at least one second filter waste outlet 41. The discharged waste may undergo further treatment, such as dehydration or drying.

[0133] The first filter chamber 15 of the first filter unit FT1 has a larger volume than the second filter chamber 35 of the second filter unit FT2. The filtration methods of the first filter unit FT1 and the second filter unit FT2 closely correspond to those described herein. Figure 4 and Figure 5 The filtration method 100 is described above. However, in this embodiment, the flow rate per unit cross-sectional area of ​​the filter medium in the first static filter pack FP1 is higher than the flow rate per unit cross-sectional area of ​​the filter medium in the second static filter pack FP2. By reducing the flow rate in the second static filter pack FP2, the filtration of the flushing liquid discharged from the first filtration unit FT1 can be improved. The flow rate per unit cross-sectional area of ​​the filter medium in the first static filter pack FP1 can be two, three, four, or more times the flow rate per unit cross-sectional area of ​​the filter medium in the second static filter pack FP2. The flow rate per unit cross-sectional area of ​​the filter medium in the second static filter pack FP2 can be in the range of 10 m³ / m² / h to 30 m³ / m² / h or 15 m³ / m² / h to 25 m³ / m² / h. The flow rate per unit cross-sectional area of ​​the filter medium in the first static filter pack FP1 can be greater than or equal to 30 m³ / m² / h, 50 m³ / m² / h, or 70 m³ / m² / h.

[0134] In at least some embodiments, the second filter unit FT2 reduces water consumption of the liquid filtration system 1. The second filter unit FT2 enables the recycling of at least some of the flushing fluid for cleaning the first filter unit FT1. The waste discharged from the second filter unit FT2 is concentrated. The accumulated waste can be disposed of in a conventional manner or may undergo further treatment, such as drying or dewatering to reduce its water content.

[0135] This embodiment has been described with reference to a first filtration unit FT1 in the form of a drum filter. Other types of filters, such as screen filters, may have similar configurations in which a flushing fluid is supplied to prevent clogging of the screen or filter mesh. It should be understood that the liquid filtration system 1 and liquid filtration method 300 according to this embodiment can be modified to accommodate different types of filters. For example, the first filtration unit FT1 may include a screen filter instead of a drum filter.

[0136] In each of the above embodiments, the second filter unit FT2 is configured to perform mechanical filtration of water to remove at least some solid particles suspended in the water discharged from the first filter unit FT1. The second filter chamber 35 is formed by a filter tank 57. At least one second filter inlet 37, at least one second filter outlet 39, and at least one second filter waste outlet 41 are formed in the filter tank 57. At least one second filter inlet 37 is located in the lower region of the second filter unit FT2; and at least one second filter outlet 39 is located in the upper region of the second filter unit FT2. This configuration is suitable for the second filter unit FT2 in this embodiment, where an upward flow of water is established. If the second filter unit FT2 is configured to establish a downward flow of water, the relative positions of at least one second filter inlet 37 and at least one second filter outlet 39 can be reversed. As described herein, the second filter unit FT2 mechanically filters the flushing liquid discharged from the first filter unit FT1. The flushing liquid supplied to the second filter unit FT2 is filtered by the filter element 43 to remove at least some waste transported along with the flushing liquid discharged from the first filter unit FT1. The second filtered liquid is discharged from the second filtration unit FT2 through at least one second filtration outlet 39.

[0137] The second filter medium 33 includes a plurality of filter elements 43. As described herein, the first filter medium 33 may also optionally include a plurality of filter elements 43. The filter element 43 in this embodiment includes an open unit structure. A schematic diagram of one of the filter elements 43 is shown in Figure 11A and Figure 11B A perspective view of a variant of one of the filter elements 43 is shown in the middle. Figure 11C The size of filter element 43 is in the middle. Figure 11CThe dimensions are shown by way of example. The indicated dimensions have a tolerance of ± 1 mm. The inner wall of the mechanical filter element 71 has a thickness of approximately 0.75 mm to 1 mm. A plurality of external ribs are formed around the outer periphery of the filter element 43. The ribs have a radial length of approximately 0.5 mm to 1 mm. It will be understood that filter elements 43 of different sizes may be used in the liquid filtration system 1 described herein. The filter element 43 has a non-porous structure and each comprises one or more filter units 45. The filter element 43 comprises walls (inner and outer) forming one or more filter units 45. The walls are impermeable and prevent liquid from flowing between adjacent filter units 45. The one or more filter units 45 each have a substantially uniform profile along the length of the filter element 43. The one or more filter units 45 are open at each end. In this embodiment, each filter unit 45 has a cross-sectional area in the range of one (1) to five (5) square millimeters and a length greater than or equal to six (6) millimeters. Filter elements 43 are collectively formed into a static filter pack FP1 in the second filter chamber 35. In this embodiment, the filter elements 43 have positive buoyancy in water. The filter elements 43 float in the water within the second filter chamber 35 and form the static filter pack FP1 in the upper region of the second filter chamber 35. In a variant, the filter elements 43 may have negative buoyancy and may form the static filter pack FP1 in the lower region of the second filter chamber 35. The filter elements 43 effectively filter by promoting the settling of solid particles suspended in the water. The solid particles settle within the filter unit 45 and settle onto the surface of the filter elements 43. In this embodiment, the filter elements 43 are formed by extruding a polymer. Other techniques may be used to form the filter elements 43.

[0138] The second filter unit FT2 is periodically cleaned to remove solids accumulated in the second filter chamber 35. Cleaning the second filter unit FT2 includes flushing the second filter chamber 35 to remove accumulated waste. The second filter unit FT2 can be cleaned while the first filter unit FT1 is operating in filtration mode. Cleaning the second filter unit FT2 includes closing at least one second filter inlet 37 and at least one second filter outlet 39. The second filter waste outlet 41 is closed during the cleaning operation and then opened to flush (or drain) the second filter unit FT2. The second filter inlet valve SFV-1 is selectively operated to open and close at least one second filter inlet 37; and the second filter outlet valve SFV-2 is selectively operated to open and close at least one second filter outlet 39. The second filter waste valve SFV-3 is selectively controlled to open and close the second filter waste outlet 41. During the cleaning of the second filter unit FT2, the second filter inlet valve SFV-1 and the second filter outlet valve SFV-2 are closed.

[0139] The packaged fluid is then introduced into the second filter chamber 35 to break the static filter pack FP1. In this embodiment, the second filter fluid control valve SFV-4 is opened to introduce the packaged fluid into the second filter chamber 35. Pressurized air is introduced into the second filter chamber 35 and breaks the static filter pack FP1. The pressurized air effectively agitates the filter element 43. Accumulated waste is thereby removed from the surface of the filter element 43 and / or from the filter cell 45. The air supply continues for a predetermined period of time. This period can be determined, for example, by empirical analysis. The second filter waste valve SFV-3 is then operated to open the second filter waste outlet 41. Rinse fluid is discharged from the second filter chamber 35 and acts as a rinsing liquid, which conveys the waste accumulated in the second filter chamber 35 to the waste disposal area. Optionally, the supply of pressurized air continues after the second filter waste outlet 41 is opened. After the second filter chamber 35 has been discharged, the second filter waste valve SFV-3 is closed to close the second filter waste outlet 41. The supply of air to the second filter chamber 35 is stopped by closing the second filter fluid control valve SFV-4. When the liquid filtration system 1 is operating in filtration mode, at least one second filter inlet 37 remains closed.

[0140] At least some of the second filtered water discharged from the second filter chamber 35 may optionally be returned within the liquid filtration system 1 for further filtration. For example, a return line (not shown) may be provided to return at least some of the second filtered water discharged from the second filter unit FT2.

[0141] In use, the perforated filter element 43 forms a static filter bag FP1 operable to filter solids from water. The filter element 43 may have positive, negative, or neutral buoyancy. The filter element 43 provides a perforated structure with high retention capacity. The flow rate per unit cross-sectional area of ​​the static filter bag FP1 can be 20 m³ / m² / h. The flow rate per unit cross-sectional area of ​​the static filter bag FP1 can be less than 20 m³ / m² / h, for example, in the range of 0.1 m³ / m² / h to 19.9 m³ / m² / h; 5 m³ / m² / h to 19.5 m³ / m² / h; or 11 m³ / m² / h to 19 m³ / m² / h. The flow rate per unit cross-sectional area of ​​the static filter bag FP1 can be greater than 20 m³ / m² / h, for example, greater than 50 m³ / m² / h. A static filter pack FP1 with a flow rate of less than or equal to 20 m³ / m² / h per unit cross-sectional area is suitable for performing single-pass filtration consisting of a single filtration cycle. A static filter pack FP1 with a flow rate of greater than or equal to 20 m³ / m² / h per unit cross-sectional area is suitable for performing multi-pass filtration comprising multiple filtration cycles. It is known that these flow rates per unit cross-sectional area are particularly effective in removing flocs (also known as flocs) from water. These flocs comprise or consist of loosely aggregated particles or flakes. In at least some embodiments, the flocs may settle within or on the exterior of the filter cell 45 of the filter element 43. The relatively low flow rate through the static filter pack FP1 helps to reduce or avoid floc disruption. Higher flow rates may potentially cause certain types of flocs to break down or decompose into smaller flocs or individual particles. In at least some embodiments, the liquid filtration system 1 is capable of capturing very fine particles suspended in water.

[0142] The flow rate per unit cross-sectional area of ​​the second filter medium 33 affects water filtration. The retention capacity of the second filter unit FT2 depends on the volume of the second filter medium 33 in the second filter chamber 35. To promote the cleaning of the second filter medium 33, the second filter medium 33 preferably occupies approximately 40% to 60% of the volume of the second filter chamber 35. In a preferred embodiment, the second filter medium 33 occupies approximately 50% of the volume of the second filter chamber 35.

[0143] The second filter unit FT2 may contain filter tanks of different sizes. The mechanical filter tank 57 may contain or be composed of cylindrical segments with a circular cross-section. The mechanical filter tank 57 may have different cross-sections, such as polygonal, rectangular, or square. The mechanical filter tank 57 may be oriented such that its central longitudinal axis extends vertically or horizontally.

[0144] Figure 11AThe first mechanical filter tank 57A is shown by way of example. The first mechanical filter tank 57 includes cylindrical sectors. The first mechanical filter tank 57 includes a second filter inlet 37, a second filter outlet 39, and a second filter waste outlet 41. The cylindrical sectors of the first mechanical filter tank 57A have a diameter of 1.2 m.

[0145] Figure 11B The second mechanical filter tank 57B is shown by way of example. The second mechanical filter tank 57B includes cylindrical sectors. The second mechanical filter tank 57B includes a second filter inlet 37, a second filter outlet 39, and a second filter waste outlet 41. The cylindrical sectors of the first mechanical filter tank 57B have a diameter of 0.9 m.

[0146] Figure 11C The third mechanical filter tank 57C is shown as an example. The third mechanical filter tank 57C includes cylindrical sectors. The third mechanical filter tank 57C includes a second filter inlet 37, a second filter outlet 39, and a second filter waste outlet 41. The cylindrical sectors of the third mechanical filter tank 57C have a diameter of 0.75 m.

[0147] Figure 11D illustrates a fourth mechanical filter tank 57D by way of example. The fourth mechanical filter tank 57D comprises cylindrical sectors. The fourth mechanical filter tank 57D comprises a second filter inlet 37, a second filter outlet 39, and a second filter waste outlet 41. The cylindrical sectors of the fourth mechanical filter tank 57D have a diameter of 0.6 m.

[0148] Figure 11E illustrates the fifth mechanical filter tank 57E by way of example. The fourth mechanical filter tank 57 comprises cylindrical sectors. The fourth mechanical filter tank 57E comprises a second filter inlet 37, a second filter outlet 39, and a second filter waste outlet 41. The cylindrical sectors of the fourth mechanical filter tank 57E have a diameter of 0.5 m.

[0149] The size of the second filtration unit FT2 depends on the flow rate of the water to be filtered.

[0150] In the above embodiments, the filtration of unfiltered (raw) water is described as a single filtration stage performed by a single first filter unit FT1. It will be understood that the filtration may include multiple filtration stages, for example, performed by two or more first filters 11. The first filters 11 may be arranged in series or in parallel. The first filters 11 may have similar configurations or may have different configurations. Furthermore, the liquid filtration system 1 may include two or more different types of first filter units FT1 for filtering unfiltered liquids.

[0151] In the above embodiments, the secondary filtration of unfiltered (raw) water is described as a single filtration stage performed by a single second filtration unit FT2. It should be understood that secondary filtration may include multiple filtration stages, for example, performed by two or more second filters 31. The second filters 31 may be arranged in series or in parallel. The multiple second filters 11 may have similar configurations or may have different configurations.

[0152] Liquid filtration system 1 and liquid filtration methods 100, 200, and 300 are described with reference to the filtration of purified water and wastewater. Clean water may, for example, contain or consist of drinking (potable) water. Liquid filtration system 1 and liquid filtration method 100 can be used to filter water used or discharged in industrial or chemical processes. The water may not have undergone biological filtration before being supplied to liquid filtration system 1. The water may optionally have undergone chemical filtration before being supplied to liquid filtration system 1. It will be understood that liquid filtration system 1 and liquid filtration methods 100, 200, and 300 described herein can be used to filter liquids other than water.

[0153] It should be understood that various changes and modifications can be made to this invention without departing from the scope of this application.

[0154] First flowchart label

[0155] 110 Operation in filtering mode 115 The first filter removes waste from the liquid. 120 Filtered liquid is discharged from the first filter. 125 Operate in flush mode 130 Introduce flushing fluid to rinse the first filter. 135 Discharge used flushing fluid and waste into the second filter. 140 The used rinsing fluid is filtered by a second filter with a porous filter medium. 145 Filtered liquid is discharged from the second filter. 150 The filtered liquid is supplied from the second filter to the first filter for filtration. 155 Clean the second filter 160 Introducing fluid to disrupt the filter components in the second filter 165 Concentrated waste is discharged from the second filter.

[0156] Second flowchart label

[0157] 210 Operation in filtering mode 215 The first filter removes waste from the liquid. 220 The first filtered liquid is discharged from the first filter. 225 Operate in flush mode 230 Introduce flushing fluid to rinse the first filter. 235 Discharge used flushing fluid and waste into the second filter. 240 The used rinsing fluid is filtered by a second filter with a porous filter medium. 245 Filtered liquid is discharged from the second filter. 250 The second filter from the discharge to the system outlet at least filters the liquid. 255 Clean the second filter 260 Introducing fluid to disrupt the filter components in the second filter 265 Concentrated waste is discharged from the second filter.

[0158] Third flowchart label

[0159] 610 Screening water supplied by the storage tank 615 Chemical treatment of water 620 Settling of suspended waste 625 Filtered water 630 Disinfectant 635 Discharge of drinking (potable) water

[0160] Fourth Flowchart Label

[0161] 310 Liquid supplied to the first filter 315 The first filter removes waste from the liquid. 320 The first filtered liquid is discharged from the first filter. 325 Supply flushing fluid to the first filter 330 Rinse fluid used to rinse the first filter 335 Discharge used flushing fluid and waste into the second filter. 340 The used rinsing fluid is filtered by a second filter with a porous filter medium. 345 Filtered liquid is discharged from the second filter. 350 Optional recycling of the second filtered liquid 355 Clean the second filter 360 Introducing fluid to disrupt the filter components in the second filter 365 Concentrated waste is discharged from the second filter.

Claims

1. A liquid filtration method for filtering liquid to remove waste, the liquid filtration method comprising: The liquid is filtered using a first filter and a first filtered liquid is discharged from the first filter, the first filter accumulating waste material filtered from the liquid; The first filter is flushed with a flushing solution to remove at least some of the accumulated waste from the first filter, and the flushing solution and at least some of the removed waste are discharged from the first filter. The flushing liquid discharged from the first filter is filtered using a second filter, and a second filtered liquid is discharged from the second filter, which accumulates waste filtered from the flushing liquid. The second filter includes an open-pore filter medium containing multiple filter elements that form a static filter bag. Each filter element has one or more filter cells. The static filter bag filters the flushing liquid discharged from the first filter.

2. The liquid filtration method of claim 1, comprising introducing at least some of the second filtered liquid discharged from the second filter into the first filter.

3. The liquid filtration method of claim 2, wherein the at least some of the second filtered liquid is introduced directly into the first filter or introduced upstream of the first filter.

4. The liquid filtration method according to any one of claims 1, 2 or 3, wherein at least some of the first filtered liquid and / or at least some of the second filtered liquid are discharged to one or more system outlets.

5. The liquid filtration method according to any one of claims 1 to 4, wherein waste filtered from the rinsing fluid accumulates in the static filter bag and / or in the filter cells of the open-pore filter medium, wherein the method comprises rinsing the second filter to discharge at least some of the accumulated waste from the second filter.

6. The liquid filtration method of claim 5, wherein rinsing the second filter comprises introducing fluid into the second filter to break up the static filter pack and / or remove waste from the filter cell.

7. A liquid filtration method as claimed in any of the preceding claims, comprising a filtration method and a rinsing method; wherein the first filter filters the liquid during the filtration method, and the first filter is rinsed during the rinsing method; wherein the filtration method and the rinsing method are performed sequentially or simultaneously.

8. The liquid filtration method as described in any of the preceding claims, wherein the liquid comprises or is composed of water.

9. The liquid filtration method as described in any of the preceding claims, wherein the liquid is purified water.

10. The liquid filtration method according to any one of claims 1 to 8, wherein the liquid is wastewater.

11. A liquid treatment method comprising the liquid filtration method as described in any of the preceding claims.

12. A liquid filtration system for filtering liquid to remove waste, the liquid filtration system comprising: The first filter unit includes: At least one first filter inlet is provided for receiving the liquid to be filtered; The first filter is used to filter waste from the liquid; At least one first filter outlet is provided for discharging the first filtered liquid; Rinse fluid supply, used to supply rinsing fluid to rinse the first filter; as well as At least one first filter waste outlet for discharging the flushing fluid; The second filtering unit includes: At least one second filter inlet is provided for receiving the flushing liquid discharged from the first filter unit; A second filter is used to filter waste from the flushing fluid; as well as At least one second filter outlet for discharging a second filtered liquid; The second filter includes an open-pore filter medium containing multiple filter elements for forming a static filter pack, each filter element having one or more filter cells.

13. The liquid filtration system of claim 12, comprising at least one supply line for supplying the second filtered liquid to the first filter.

14. The liquid filtration system of claim 13, wherein the at least one supply line is directly connected to the first filtration unit or connected upstream of the first filtration unit.

15. The liquid filtration system of claim 12, 13 or 14, wherein the at least one first filter outlet and the at least one second filter outlet are connected to one or more system outlets for discharging the first filtered liquid and the second filtered liquid.

16. The liquid filtration system of any one of claims 12 to 15, wherein the second filter unit is configured to be flushed to remove at least some of the waste material accumulated in the porous filter medium.

17. The liquid filtration system of claim 16, wherein the second filtration unit includes at least one fluid inlet for introducing fluid to break the static filter bag and / or remove waste from the filter cell.

18. The liquid filtration system according to any one of claims 12 to 17, wherein the liquid filtration system is configured to selectively operate in a filtration mode and a flushing mode; wherein, When operating in the filtration mode, the first filter filters the liquid; and when operating in the flushing mode, the first filter is flushed.

19. The liquid filtration system according to any one of claims 12 to 18, wherein the liquid is water.

20. The liquid filtration system according to any one of claims 12 to 19, wherein the liquid is purified water.

21. The liquid filtration system according to any one of claims 12 to 19, wherein the liquid is wastewater.

22. A liquid handling system comprising one or more liquid filtration systems as described in any one of claims 12 to 21.

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