Improvements to industrial filter assemblies

Abstract

This specification provides a filter assembly that more effectively utilizes the energy of a cleansing pulse. Specifically, the filter assembly can have directional flow resistance by including a flow control unit located downstream of the filter component. This flow control unit prevents the fluid flow from the cleansing pulse from dissipating through the filter component during cleansing, but allows sufficient fluid flow to flow forward through the filter component during normal operation.

Description

[Technical Field]

[0001] Cross-references to related applications This application claims the interests of Provisional Application No. 63 / 536,135, filed on 1 September 2023, which is incorporated herein by reference in its entirety for all purposes.

[0002] field This disclosure generally relates to a filter assembly having direction-dependent flow resistance, the filter assembly including a filter component and a flow control unit. [Background technology]

[0003] background Removing particulate matter from fluid flows has been a long-standing practice in various industrial sectors. Conventional methods for filtering particulate matter from fluid flows include, but are not limited to, filter assemblies (e.g., filter bags), filter tubes, filter cartridges, and filter panels. These filter elements are typically directed towards filtration systems, often called filter bag houses, for filtering such particulate matter. Such filtration systems may be either purifiable or non-purifiable depending on the requirements of system operation.

[0004] Separating particulate matter from industrial fluid flows is often done using laminate filters. These textile-based laminate filters remove particulate matter from the fluid flow. When the accumulation of particulate matter on the filter causes significant flow resistance or pressure drop as the fluid passes through the textile, the filter must be cleaned and the particulate matter removed from the filter.

[0005] In the industrial filtration market, it is common to characterize filter assembly types by their purification method. The most common types of purification technologies are reverse air, shaker, and pulse jet. Reverse air and shaker technologies are considered low-energy purification technologies.

[0006] In reverse air filtration technology, particulate matter is collected inside a bag. During purification, the bag is crushed by gentle reverse air washing, breaking up the dust cake from the bag and discharging it from the bottom of the bag into a hopper.

[0007] The shaking mechanism also cleans the dust cake collected inside the bag. The top of the bag is attached to a vibrating arm, which generates a sine wave inside the bag to remove the dust cake.

[0008] In pulsed jet filtration, particulate matter is captured on the outside of the bag. Pulsed jet cleaning technology uses short pulses of compressed air to propel the particulate matter into the upper interior of the filter assembly. In pulsed jet filtration, the filter assembly is positioned vertically with an opening at the top (i.e., the upper interior). The energy of this cleaning pulse expands the filter assembly, knocking the dust cake off. Typically, the bag snaps back into cage support and immediately returns to service collecting particulate matter.

[0009] Of the three cleaning technologies, pulse jet cleaning places the greatest burden on filter components. However, in recent years, industrial process engineers are increasingly choosing pulse jet baghouses for dust collection applications for the following reasons: 1. The unit size is small (sometimes about half or a quarter the size of a shaker and reverse air filter). The reasons are as follows: (A) A higher volumetric airflow rate / fabric area ratio (higher operating speed when passing through filter components). (B) Online cleaning allows the unit to be designed at the desired speed, eliminating the need to increase the area of ​​filter components for offline cleaning. 2. The number of moving parts is minimized. 3. There are few bags to exchange.

[0010] In a pulse jet baghouse, the filter assembly is inserted into the baghouse with a metal cage attached to the inside to prevent the bag from collapsing. Dirty fluids containing dust enter the baghouse from the outside of the bag, and dust accumulates on the surface. Cleaned fluids (such as gases) pass through the bag and are discharged from the baghouse. When a sufficient amount of dust has accumulated on the outside of the bag and the pressure rises, the pulse jet baghouse sends pulses of high-pressure air vertically downward from the top inside the bag. The accumulated dust is pushed out of the bag and collected at the bottom of the baghouse by the movement inside the bag caused by the high-pressure air and / or the pressure pulses moving the bag downward along the filter. The movement inside the bag can be generated by the high-pressure air causing pressure spikes inside the bag and stressing the bag.

[0011] In some cases, the pressure pulse may not travel a sufficient distance along the length of the filter assembly, resulting in insufficient cleaning of the bag bottom. Furthermore, this cleaning process may occur multiple times per hour to maintain sufficient fluid flow through the bag.

[0012] U.S. Patent No. 6,110,243 relates to a filter assembly comprising a support structure such as a support cage made of metal, plastic, or the like, and a filter component made of a stretched PTFE film without a support material or support layer. As described, the filter assembly further comprises a support cover or cage cover, which is fitted to the outer surface of the support cover or cage to prevent contact between the filter component and the cage.

[0013] In general, the higher the pulse energy, the higher the pressure. Industry guidelines recommend that the pulse range is 172~690kPa (25~100psi). However, even when using high-pressure pulses, the pulse jet system may sometimes not be able to effectively remove dust from the surface, causing the system to operate at a high differential pressure, which ultimately leads to reduced process efficiency in the form of increased energy costs or decreased throughput. Furthermore, there is generally a trade-off relationship between cleaning effect and product life. Since cleaning pulses impair the mechanical integrity of the filter assembly over time, increased cleaning frequency or increased pressure may reduce product life.

[0014] In filter assemblies, there is a need for improved cleaning efficiency and uniform pressure distribution along the length direction of the filter assembly. Therefore, it is advantageous to provide an improved filter assembly aimed at overcoming one or more of the above-mentioned constraints. Summary of the Invention

[0015] Abstract The present specification provides a filter assembly that more effectively utilizes the energy of cleaning pulses. Specifically, the filter assembly has direction-dependent flow resistance by including a flow control unit comprising a support structure and a flow control component disposed downstream of the filter component. The flow control unit prevents air from the cleaning pulse from dissipating through the filter component during cleaning, and allows sufficient fluid flow to pass forward through the filter component during normal operation.

[0016] According to one embodiment ("Embodiment 1"), the present disclosure relates to a filter assembly for filtering particulate matter, comprising a filter component and a flow control unit including at least a support structure and a flow control component, wherein the filter assembly can have direction-dependent flow resistance that exhibits a first flow resistance in a first direction when exposed to a first fluid flow, and a second flow resistance in a second direction when exposed to a second fluid flow.

[0017] Embodiment 2 is the filter assembly described in Embodiment 1, wherein the flow control unit includes a thick portion and a thin portion.

[0018] Embodiment 3 is a filter assembly according to Embodiment 1 or 2, wherein the first fluid flow is a gas flow containing particulate matter.

[0019] Embodiment 4 is a filter assembly according to any one of Embodiments 1 to 3, wherein the second fluid flow has a pressure of 0.20 kPa to 760 kPa.

[0020] Embodiment 5 is a filter assembly according to any one of Embodiments 1 to 4, wherein the ratio of the first flow resistance to the second flow resistance is in the range of less than 0.01% to 99%.

[0021] Embodiment 6 is a filter assembly according to any of Embodiments 2 to 5, wherein the thicker portion covers at least 60% of the flow control unit.

[0022] Embodiment 7 is a filter assembly according to any of Embodiments 1 to 6, wherein when the filter assembly is exposed to a second fluid flow in a second direction, the pressure within the filter assembly increases compared to the same second fluid flow in the absence of the flow control unit.

[0023] Embodiment 8 is a filter assembly according to any one of Embodiments 1 to 7, wherein the flow control unit is located downstream of the filter component with respect to the first direction of the first fluid flow.

[0024] Embodiment 9 is a filter assembly according to any one of Embodiments 1 to 8, wherein the flow control unit alternately transitions between a relaxed, unmasked state and an extended, masked state with respect to the filter component.

[0025] Embodiment 10 is a filter assembly according to Embodiment 9, wherein the flow control unit is in an extended masking state, and at least a portion of the flow control surface of the flow control unit is in contact with the surface of the filter component.

[0026] Embodiment 11 is a filter assembly according to any of Embodiments 1 to 10, wherein the flow control unit includes a plurality of flow control passages, or the flow control unit includes a region with varying thickness.

[0027] Embodiment 12 is a filter assembly according to Embodiment 11, wherein the flow control unit has an opening area of ​​0.01% to 50% of the total surface area of ​​the flow control unit.

[0028] Embodiment 13 is a filter assembly according to Embodiment 11 or 12, wherein the flow control passage has an average size of 0.0001 to 100,000 mm. 2 Includes the opening.

[0029] Embodiment 14 is a filter assembly according to any one of Embodiments 1 to 13, wherein the flow control unit includes at least one flow control passage that can be in an open or closed state.

[0030] Embodiment 15 is the filter assembly described in Embodiment 14, wherein the at least one flow control passage includes a flap.

[0031] Embodiment 16 is a filter assembly according to any one of Embodiments 1 to 15, wherein the first fluid flow passing through the filter assembly in the first direction at a first velocity experiences a first flow resistance, the second fluid flow passing through the filter assembly in the second direction at a second velocity experiences a second flow resistance, and the first flow resistance is different from the second flow resistance.

[0032] Embodiment 17 is a filter assembly according to any of Embodiments 1 to 16, wherein the second flow resistance is greater than the first flow resistance.

[0033] Embodiment 18 is a filter assembly according to any of Embodiments 1 to 17, wherein the first fluid flow passing through the filter assembly in the first direction receives a first flow resistance of less than 4,000 (min × Pa) / m.

[0034] Embodiment 19 is a filter assembly according to any of Embodiments 1 to 18, wherein the second fluid flow passing through the filter assembly in the second direction is subjected to a second flow resistance of more than 10 (min × Pa) / m.

[0035] Embodiment 20 is a filter assembly according to any of Embodiments 1 to 19, wherein the filter assembly is cleanable.

[0036] Embodiment 21 is a filter assembly according to any one of Embodiments 1 to 20, wherein the flow control unit includes a sheet-like material, and the sheet-like material includes a porous sheet-like material, a non-porous sheet-like material, or a combination thereof.

[0037] Embodiment 22 is a filter assembly according to Embodiment 21, wherein the sheet material comprises silicone, silicone elastomer, fluorocarbon, fluorocarbon elastomer, microporous polymer densified or filled to remove at least some pores, polyacrylate, ethylene (meth)acrylic copolymer, polyimide, polyether ether ketone (PEEK), polyester, polybutylene terephthalate, polyethylene terephthalate, microporous polymer, wherein the polymer is polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), stretched PTFE, fluorinated ethylene propylene (FEP), perfluoroalkoxy polymer (PFA), ultra-high molecular weight polyethylene (UHMWPE), nitrocellulose, triacetylcellulose, polyamide, polycarbonate, polysulfone, polyvinyl chloride, polyvinylidene fluoride, acrylate copolymer, or a combination thereof.

[0038] Embodiment 23 is a filter assembly according to Embodiment 21 or 22, wherein the sheet material has a flow resistance greater than 16.5 (min × Pa) / m.

[0039] Embodiment 24 is a method for cleaning a baghouse filter system, comprising providing a clean fluid flow at a pressure of 0.20 to 760 kPa through one or more filter assemblies described in any of Embodiments 1 to 23 attached to a tube sheet, thereby causing expansion of a flow control unit, which in turn applies and dissipates mechanical pressure to the filter components in response to the clean pulse, thereby inducing cleaning of the filter components.

[0040] Embodiment 25 is a flow control unit for use in a filter assembly, comprising one or more flow control passages, wherein the filter assembly may have a directional flow resistance having a first flow resistance in a first direction and a second flow resistance in a second direction when exposed to a fluid flow.

[0041] Embodiment 26 is a flow control unit as described in Embodiment 25, wherein the flow control component has an opening area of ​​0.01% to 50% of the total area of ​​the flow control unit.

[0042] Embodiment 27 is a flow control unit as described in Embodiment 26, wherein the difference between the first flow resistance and the second flow resistance increases as the % opening area of ​​the flow control unit decreases.

[0043] Embodiment 28 is a flow control unit according to any one of Embodiments 25 to 27, wherein the flow control passage has an average size of 0.0001 to 100,000 mm. 2 It includes an opening.

[0044] Embodiment 29 is a flow control unit according to Embodiment 28, wherein the difference between the first flow resistance and the second flow resistance increases as the average size of the opening decreases.

[0045] Embodiment 30 is a flow control unit according to Embodiment 28 or 29, further comprising one or more flaps such that one or more flow control passages can be in an open or closed state.

[0046] The embodiments described above are merely examples and should not be read as limiting or narrowing the scope of the inventive concept provided otherwise by this disclosure. Although several examples are disclosed, further embodiments will become apparent to those skilled in the art from the following detailed description, which illustrates and explains exemplary examples. Therefore, the drawings and detailed description should be considered as illustrative and not limiting in nature. [Brief explanation of the drawing]

[0047] Brief explanation of the drawing The accompanying drawings are included to further enhance the understanding of this disclosure, are incorporated herein, constitute part thereof, illustrate embodiments, and help to illustrate the principles of this disclosure together with the description herein.

[0048] [Figure 1] Figure 1 is a schematic diagram of a pulse jet baghouse according to an embodiment disclosed herein.

[0049] [Figure 2A] Figure 2A is a schematic cross-sectional view of a filter assembly for use in a conventional pulse jet baghouse in forward flow (also referred to herein as "normal flow").

[0050] [Figure 2B] Figure 2B is a schematic cross-sectional view of a filter assembly for use in a conventional pulse jet baghouse in a clean pulse flow (also referred to herein as “counterflow”).

[0051] [Figure 3A] Figure 3A is a schematic cross-sectional view of a filter assembly for use in a pulse jet baghouse, according to an embodiment disclosed herein, when exposed to a first fluid flow.

[0052] [Figure 3B] Figure 3B is a schematic cross-sectional view of a filter assembly for use in a pulse jet baghouse, according to an embodiment disclosed herein, when exposed to a second fluid flow.

[0053] [Figure 3C] Figure 3C is a schematic cross-sectional view of a filter assembly for use in a pulse jet baghouse, according to an embodiment disclosed herein, when exposed to a second fluid flow.

[0054] [Figure 3D] Figure 3D is a schematic cross-sectional view of a filter assembly for use in a pulse jet baghouse, according to an embodiment disclosed herein, when exposed to a second fluid flow.

[0055] [Figure 4A] Figure 4A is a schematic cross-sectional view along the length of a filter assembly for use in a pulse jet baghouse according to an embodiment disclosed herein.

[0056] [Figure 4B] Figure 4B is a schematic horizontal cross-sectional view of a filter assembly in normal and counter-flow conditions for use in a pulse jet baghouse according to embodiments disclosed herein. [Figure 4C] Figure 4C is a schematic horizontal cross-sectional view of a filter assembly in normal and counterflow conditions for use in a pulse jet baghouse according to embodiments disclosed herein. [Figure 4D] Figure 4D is a schematic horizontal cross-sectional view of a filter assembly in normal and counter-flow conditions for use in a pulse jet baghouse according to embodiments disclosed herein.

[0057] [Figure 5A] Figure 5A is a schematic cross-sectional view along the length of a filter assembly for use in a pulse jet baghouse according to an embodiment disclosed herein, in normal and counter-flow conditions. [Figure 5B] Figure 5B is a schematic cross-sectional view along the length of a filter assembly for use in a pulse jet baghouse according to an embodiment disclosed herein, in normal and counter-flow conditions.

[0058] [Figure 5C] Figure 5C is a schematic horizontal cross-sectional view of a filter assembly in normal and counter-flow conditions for use in a pulse jet baghouse according to embodiments disclosed herein. [Figure 5D] Figure 5D is a schematic horizontal cross-sectional view of a filter assembly in normal and counter-flow conditions for use in a pulse jet baghouse according to embodiments disclosed herein.

[0059] [Figure 6A]Figure 6A is a schematic cross-sectional view of a filter assembly for use in a reverse air filter according to an embodiment disclosed herein, in normal and reverse flow. [Figure 6B] Figure 6B is a schematic cross-sectional view of a filter assembly for use in a reverse air filter according to an embodiment disclosed herein, in normal and reverse flow.

[0060] [Figure 7] Figure 7 is a line graph showing the pressure (kPa) measured at various locations in a conventional filter assembly.

[0061] [Figure 8] Figure 8 is a line graph showing the pressure (kPa) measured at various locations in the filter assembly according to the embodiments disclosed herein.

[0062] [Figure 9A] Figure 9A is a line graph showing a comparison of pressure (kPa) versus time measured at one location for a conventional filter assembly and a filter assembly according to an embodiment disclosed herein. [Figure 9B] Figure 9B is a line graph showing a comparison of pressure (kPa) versus time measured at one location for a conventional filter assembly and a filter assembly according to an embodiment disclosed herein. [Figure 9C] Figure 9C is a line graph showing a comparison of pressure (kPa) versus time measured at one location for a conventional filter assembly and a filter assembly according to an embodiment disclosed herein.

[0063] [Figure 10] Figure 10 is a line graph showing a comparison of pressures (kPa) measured at various locations in a conventional filter assembly and a filter assembly according to the embodiments disclosed herein.

[0064] [Figure 11A]Figure 11A is a schematic cross-sectional view of a filter assembly used in a pulse jet baghouse according to an embodiment disclosed herein when exposed to a first fluid flow.

[0065] [Figure 11B] Figure 11B is a schematic cross-sectional excerpt of a filter assembly used in a pulse jet baghouse according to an embodiment disclosed herein when exposed to a second fluid flow.

[0066] [Figure 11C] Figure 11C is a schematic cross-sectional view of a filter assembly used in a pulse jet baghouse according to an embodiment disclosed herein when exposed to a second fluid flow.

[0067] [Figure 12A] Figure 12A is a schematic cross-sectional view of a filter assembly used in a pulse jet baghouse according to an embodiment disclosed herein when exposed to a first fluid flow.

[0068] [Figure 12B] Figure 12B is a schematic cross-sectional view of a filter assembly used in a pulse jet baghouse according to an embodiment disclosed herein when exposed to a second fluid flow. [Modes for carrying out the invention]

[0069] Detailed explanation Definitions and Terms This disclosure is not intended to be read restrictively. For example, terms used in this application should be read broadly in the context of the meanings that technicians of the art assign to such terms.

[0070] With regard to terms relating to inaccuracy, the terms “about” and “approximately” may be used interchangeably to refer to measurements including the stated measurement and measurements that are reasonably close to the stated measurement. A measurement that is reasonably close to the stated measurement deviates by a reasonably small amount from the stated measurement, as can be understood and readily verified by a person skilled in the art in the relevant technology. Such deviations may be due, for example, to measurement errors, differences in the calibration of measuring instruments and / or manufacturing equipment, human error in reading and / or setting of measurements, minor adjustments made to optimize performance and / or structural parameters to account for differences in measurements related to other components, specific implementation scenarios, improper adjustment and / or handling of an object by a person or machine, and / or similar. Where a person skilled in the art in the relevant technology is deemed unable to readily determine the value of such a reasonably small difference, the terms “about” and “approximately” shall be understood to mean plus or minus 10% of the stated value.

[0071] As used herein, “filter assembly” may be used in a baghouse for filtering particulate matter from a fluid flow, such as an exhaust gas flow. The filter assembly may be in the form of a filter bag.

[0072] A "filter component" may include at least one filter medium for recovering particulate matter from a fluid flow, such as a gas flow. A filter assembly may include one or more filter components. A filter component includes at least one filter medium that is fluid-permeable while recovering particulate matter on the upstream surface of the filter component and / or in at least a portion of the structure of the filter component.

[0073] The term "fluid flow" can encompass gas flows or air flows. Gas flows can include gas flows from many industrial processes, such as fuel gas flows or exhaust gas flows from combustion plants. These gas flows contain reaction products of fuel and combustion air, such as particulate matter (dust), sulfur oxides, nitrogen oxides, and carbon monoxide. In some embodiments, a first fluid flow and a second fluid flow may exist.

[0074] The term "normal operation" means that the fluid flow through the filter assembly in a direction that removes and recovers particulate matter in the fluid flow. The fluid flow under "normal operation" can be the first fluid flow.

[0075] The terms "normal direction" or "first direction" refer to the direction in which the fluid flow normally occurs during operation. In some embodiments, a first and a second direction may exist. In some embodiments, the normal direction may be the first direction opposite to the second direction. The fluid flow in the normal direction may be the first fluid flow. Furthermore, a third direction may exist for the fluid flow longitudinally along the length of the filter assembly.

[0076] The terms “opposite direction” or “second direction” refer to the direction in which the fluid flow flows through the filter assembly during a clean pulse or clean flow. In some embodiments, the second direction can be the opposite direction. The fluid flow flowing in the opposite direction can be the second fluid flow.

[0077] "Forward flow" refers to fluid flow that flows in the normal direction. In some embodiments, the fluid flow can flow toward the center of the filter assembly in a direction perpendicular to the longitudinal direction along the length of the filter assembly.

[0078] "Opposite-direction flow" refers to a fluid flow that flows in the opposite direction to the forward flow.

[0079] "Upstream fluid flow" refers to the fluid flow containing particulate matter before it passes through the filter assembly.

[0080] "Downstream fluid flow" refers to the fluid flow that has passed through the filter assembly and is relatively cleaner than the upstream fluid flow.

[0081] In some embodiments, a first flow and a second flow may exist, where the first flow is a forward flow and the second flow is a counterflow. In some embodiments, the counterflow describes a fluid flow that moves away from the center of the filter assembly and flows perpendicular to the longitudinal direction along the length of the filter assembly. Furthermore, a third flow may also exist, which flows longitudinally along the length of the filter assembly as the downstream fluid flow (e.g., the cleaned fluid in the filter assembly) exits the filter assembly.

[0082] The term "flow resistance" describes the resistance of a filter assembly to the fluid flowing through it.

[0083] A "flow control component" can be used in a filter assembly so that the filter assembly has direction-dependent flow resistance.

[0084] A "flow control unit" refers to a structure in which flow control components are integrated into a support structure.

[0085] The term "direction-dependent flow resistance" describes a filter assembly that has different flow resistances depending on the direction of the flow. In some embodiments, a filter assembly may have a first flow resistance in the normal direction and a second flow resistance in the opposite direction. In embodiments, a filter assembly may have a first flow resistance in the first direction when exposed to a first fluid flow and a second flow resistance in the second direction when exposed to a second fluid flow.

[0086] Description of various embodiments Those skilled in the art will readily understand that various aspects of this disclosure can be realized by any number of methods and apparatus configured to perform the intended functions. Furthermore, it should be noted that the accompanying drawings referenced herein are not necessarily drawn to scale and may be exaggerated to illustrate various aspects of this disclosure; in this respect, the drawings should not be construed as limiting.

[0087] The filter assemblies described herein can be used in a wide range of applications where the control of contaminants or the capture of products is required. These include, for example, power plants, steel mills, chemical manufacturers, and other industrial enterprises where high particulate matter recovery efficiency is required. An exemplary embodiment of the present invention is a filter assembly used in a cement baghouse. The filter assemblies described herein can be used in a baghouse for filtering particulate matter from a fluid flow, such as an exhaust gas flow. In one embodiment, a high-efficiency dust collection filter assembly may be provided.

[0088] The disclosed filter assembly is useful for filtering particulate matter from a fluid flow and comprises a filter component and a flow control component, and the filter assembly may have a directional flow resistance having a first flow resistance in a first direction when exposed to a first fluid flow and a second flow resistance in a second direction when exposed to a second fluid flow. During normal operation, the filter assembly collects particulate matter on its upstream surface, and the collected particulate matter can be removed multiple times during operation by cleaning. For example, the filter assembly can be cleaned by removing particulate matter that accumulates on the filter assembly as a dust cake using cleaning techniques such as reverse air, shakers, and pulse jets.

[0089] The various embodiments described herein relate to filter assemblies having direction-dependent flow resistance. A filter assembly may include filter components and flow control components. In one embodiment, the filter assembly may include additional support structures. In embodiments where the fluid flow is in a normal direction (e.g., a first fluid flow), the flow control components may be located downstream of the filter components. In some embodiments, the flow control components may be positioned between the filter components and the support structures. In some embodiments, the support structures may be positioned between the flow control components and the filter components.

[0090] In some embodiments, the flow control component may be integrated with the filter component. In some embodiments, the flow control component may be integrated with the support structure. In some embodiments, the filter assembly may include a flow control component integrated with the support structure, forming a flow control unit.

[0091] Flow control components may be configured such that the filter assembly has directional flow resistance. While not bound by any particular theory, the configurations disclosed herein are thought to address issues related to cleaning efficiency and product life by providing the filter assembly with a more uniform pressure distribution and higher overall pressure along the longitudinal direction of the filter assembly during the cleaning cycle. Pressure distribution will be discussed later with reference to Figure 10.

[0092] In one such configuration, the flow control component can be configured to prevent the generation of a flow in the opposite direction from the pulse of air (second fluid flow) passing through the filter component. In this configuration, the flow control component includes an air-impermeable material or a non-porous sheet-like material, thus making maximum use of the pulse energy for the expansion and masking motion of the flow control component on the surface of the filter component. The expansion and masking motion of the flow control component generates a pressure pulse directed toward the filter component in order to clean the upstream surface of the filter component.

[0093] In another configuration, the flow control component may be configured to allow fluid to pass through a filter assembly in both the normal and opposite directions, but the filter assembly has different flow resistances. In such a configuration, the flow control component may include a porous sheet material or a non-porous sheet material containing one or more flow control passages or openings. In some embodiments, the flow control component may include a tubular, or individual sheet or ribbon-like porous or non-porous sheet material. As used herein, “ribbon” means a material having a length much longer than its width and thickness. In some embodiments, the length is more than 10 times the width of the ribbon. In other embodiments, the length of the ribbon is more than 20, 30, 50, or 100 times the width of the ribbon. In other embodiments, the length of the ribbon is up to about 10,000 times the width of the ribbon. In yet another embodiment, the flow control component may be configured such that a fluid flow in the normal direction (first fluid flow) experiences a first flow resistance, and a fluid flow in the opposite direction (second fluid flow) experiences a second flow resistance that is greater than the first flow resistance. During normal operation, the fluid flow can pass through the filter assembly in its normal direction with minimal additional flow resistance.

[0094] The flow control component is in a relaxed, unmasking state during normal operation (e.g., a first fluid flow) and in an extended, masked state during a cleanup pulse or counterflow (e.g., a second fluid flow). In some embodiments, in the relaxed, unmasking state, the flow control component does not mask the filter component, and the fluid flow flowing normally through the filter assembly experiences a first flow resistance. In certain embodiments, in the extended, masked state, at least a portion of the flow control component contacts the surface of the filter component, masking the filter component, and the fluid flow flowing in the opposite direction through the filter assembly experiences a second flow resistance greater than the first flow resistance due to the extension and masking action of the flow control component against the surface of the filter component.

[0095] In some embodiments, the filter assembly may include flow control components that can be porous or non-porous sheet materials, such as membranes. The sheet material allows the passage of a fluid (e.g., gas). The filter assembly can maintain a differential pressure rise of less than 0.7 MPa, for example, less than 0.5 MPa or less than 0.1 MPa, as described in the ISO 11057 test method described later.

[0096] The disclosed filter assembly exhibits a higher flow resistance in the second direction compared to a filter assembly without flow control components. For example, if the flow control components are non-porous and / or have no passages or openings, the flow resistance of the flow control components in the second direction can be essentially infinite. In some embodiments, the flow control component is configured such that the flow resistance in the second direction is greater than 10 (min × Pa) / m, or greater than 11 (min × Pa) / m, or greater than 12 (min × Pa) / m, or greater than 13 (min × Pa) / m, or greater than 14 (min × Pa) / m, or greater than 15 (min × Pa) / m, or greater than 16 (min × Pa) / m, or greater than 16.5 (min × Pa) / m, or greater than 16.8 (min × Pa) / m, or greater than 17.1 (min × Pa) / m, or greater than 17.4 (min × Pa) / m, or greater than 17.7 (min × Pa) / m, or greater than 18.0 (min × Pa) / m, or greater than 18.3 (min × Pa) / m, or greater than 18.6 (min × Pa) / m, or 18.9 (min × Pa) / m, or Greater than 19.3 (min × Pa) / m, or greater than 20 (min × Pa) / m, or greater than 30 (min × Pa) / m, or greater than 40 (min × Pa) / m, or greater than 50 (min × Pa) / m, or greater than 60 (min × Pa) / m, or greater than 70 (min × Pa) / m, or greater than 80 (min × Pa) / m, or greater than 90 (min × Pa) / m, or greater than 100 (min × Pa) / m, or greater than 150 (min × Pa) / m, or greater than 200 (min × Pa) / m, or greater than 300 (min × Pa) / m, or greater than 500 (min × Pa) / m, or greater than 1000 (min × Pa) / m, or greater than 1500 (min × Pa) / m, or greater than 2000 (min × Pa) / m.

[0097] In the first direction, when exposed to the first fluid flow, the filter assembly can have a flow resistance of less than 4000 (min × Pa) / m. In other embodiments, the fluid assembly can have a flow resistance of less than 3500 (min × Pa) / m, or less than 3000 (min × Pa) / m, or less than 2500 (min × Pa) / m, or less than 2000 (min × Pa) / m, or less than 1500 (min × Pa) / m, or less than 1000 (min × Pa) / m, or less than 900 (min × Pa) / m, or less than 800 (min × Pa) / m, or less than 700 (min × Pa) / m, or less than 600 (min × Pa) / m, or less than 500 (min × Pa) / m, or less than 400 (min × Pa) / m, or less than 300 (min × Pa) / m, or less than 200 It may be less than (min × Pa) / m, or less than 150, or less than 125(min × Pa) / m, or less than 100(min × Pa) / m, or less than 90(min × Pa) / m, or less than 80(min × Pa) / m, or less than 70(min × Pa) / m, or less than 60(min × Pa) / m, or less than 50(min × Pa) / m, or less than 40(min × Pa) / m, or less than 30(min × Pa) / m, or less than 25(min × Pa) / m, or less than 20(min × Pa) / m, or less than 15(min × Pa) / m, or less than 12.5(min × Pa) / m, or less than 10(min × Pa) / m.

[0098] In some examples, the sheet material of the flow control component may include metal (e.g., aluminum, stainless steel, and copper) or polymer films. The polymer film may be non-porous or porous. Suitable sheet materials that are non-porous polymer films include, for example, silicone, silicone elastomer, fluorocarbon, fluorocarbon elastomer, microporous polymers densified to remove at least some of the pores, polyacrylate, ethylene (meth)acrylic copolymer, polyimide, polyether ether ketone (PEEK), polyester, polybutylene terephthalate, polyethylene terephthalate, or combinations or blends thereof. In some embodiments, the flow control component may be, for example, a porous sheet material or porous membrane containing a microporous polymer, such as polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), expanded polyethylene (ePE), stretched PTFE, fluorinated ethylene propylene (FEP), perfluoroalkoxy polymer (PFA), ultra-high molecular weight polyethylene (UHMWPE), nitrocellulose, triacetylcellulose, polyamide, polycarbonate, polysulfone, polyvinyl chloride, polyvinylidene fluoride, acrylate copolymer, microporous fluoropolymer film, textile-like material, or a combination thereof.

[0099] In some embodiments, the flow control component may include a porous membrane, which may be a PTFE or stretched PTFE ("ePTFE") sheet material. The ePTFE membrane may have an average pore diameter of 0.7 microns or less, for example, 0.5 microns or less. In some embodiments, the porous membrane may include a fluoropolymer membrane or a polyester membrane. Suitable fluoropolymer membranes include polytetrafluoroethylene (PTFE) produced by several different methods, including stretching PTFE to form stretched polytetrafluoroethylene (ePTFE). Other suitable fluoropolymers include polyvinylidene fluoride ("PVDF"), tetrafluoroethylene-hexafluoropropylene copolymer ("FEP"), tetrafluoroethylene-(perfluoroalkyl) vinyl ether copolymer ("PFA"), and the like. In some embodiments, the flow control component is a densified expandable polymer to remove at least some of the pores.

[0100] ePTFE membranes can have a structure consisting of multiple nodes and / or multiple fibrils, thereby forming pores. In some embodiments, the ePTFE membrane is substantially fibrillated and contains a small number of nodes. The use of PTFE provides excellent heat resistance and chemical inertness. Porous ePTFE improves strength and stability to withstand the stresses caused by pulsed jet cleaning. There are two types of stresses on the membrane: one caused by rapid expansion during pulsed jet cleaning; the other caused by the sudden collapse of the bag against the supporting structure. These stresses occur repeatedly throughout the lifespan of the filter assembly, which can be several years. Some applications of filter assemblies may involve more than one million pulse cycles per year of operation.

[0101] In certain embodiments, the filter component may include a filter medium made from woven felt, nonwoven felt, polyester, cotton, nylon, glass fiber material, catalytic filter material, or adsorbent filter material, and optionally a support structure. In some embodiments, the filter component includes felt or fibers made from PTFE, polyester, polypropylene, polyphenylene sulfide, aramid, polyimide, or combinations thereof. In certain embodiments, the filter component may include mixed fibers and filaments, including glass fiber and PTFE. In some embodiments, the filter component includes a material capable of withstanding high-temperature applications above 400°C. This material may be woven PTFE, glass fiber, or polyimide. The filter component may also include a laminate comprising a porous filter membrane, such as a porous ePTFE or ePE membrane, and the aforementioned woven or nonwoven felt.

[0102] In another embodiment, the filter assembly may include a filter component and a flow control component, the filter component having pores and the flow control component optionally having flow control passages. In some embodiments, the flow control passages may be one or more openings in the flow control component. Each opening may independently take the form of a hole, slit, perforation, flap, one-way valve, or a combination thereof. As used herein, the term “one-way valve” is intended to include devices that allow fluid flow in only one direction. Suitable examples of one-way valves include, for example, spring check valves, ball check valves, poppet check valves, diaphragm check valves, mono-leaflet check valves, bi-leaflet check valves, tri-leaflet check valves, check valves, or a combination thereof. When using a sheet material containing one or more one-way valves, the one or more one-way valves may be oriented so that flow through each one-way valve is only in a first direction and closed in a second direction.

[0103] During normal operation, the flow control component can be in a relaxed state. In this relaxed state, the first fluid flow can pass through the pores of the filter component of the filter assembly and flow across the surface of the flow control component, and at least a portion of the first fluid flow can pass through any flow control passages or openings that may be present.

[0104] In yet another embodiment, the filter assembly may include a filter component and a flow control component, the filter component having pores, and the flow control component may include one or more individual tabs. For example, multiple individual tabs may be arranged on the inner portion of the filter component. Specifically, the individual tabs are attached to the filter component by a first portion or top of the tab, while a second unconnected portion of the tab is flexible and can move freely. During operation, a flow in the first direction bends the tab inward toward the center of the filter bag, while a flow in the second direction presses and holds the tab against the filter medium, thereby restricting the flow in the second direction. In a further embodiment, the flow control component may include one or more ribbons comprising a porous or non-porous sheet-like material. The ribbons can be oriented in any pattern, such as being wound vertically, horizontally, or helically on the inner portion of the filter component. For example, winding the flow control component helically can leave slit-like openings between each winding of the ribbon, resulting in the formation of long helical slits. Similarly, the flow control component may include one or more ribbons oriented longitudinally along the filter or around the periphery of the filter.

[0105] In yet another embodiment, the flow control component may include a flow control laminate comprising an elastic substrate bonded to a porous film. The porous film may have a node-fibril structure, such as ePTFE. The flow control laminate is formed by bonding the porous film to the elastic substrate when the elastic substrate is in an elongated state. Upon bonding, the tension on the elastic substrate is released, the porous film is compressed, and the fibrils between the nodes bend and wrinkle within the film plane, causing the nodes to move closer together and changing the internal structure of the film, resulting in smaller pores. When the flow control laminate is elongated again, the fibrils elongate and the pores open, allowing a greater flow rate to pass through the elongated flow control laminate compared to an unelongated flow control laminate. The flow control laminate can be bonded to a filter component to function as a flow control component. Filter components generally have a relatively small amount of elasticity compared to flow control components, i.e., flow control laminates. During operation, flow in a first direction may elongate the flow control component, opening pores and reducing the fluid flow resistance. In the second direction, the flow-controlled laminate is constrained by the filter component and cannot stretch in an essential way, so the pores remain closed and the flow in the second direction is reduced.

[0106] Flow control components can be incorporated into a filter assembly as separable components and can be attached to the filter components by, for example, one or more of the following: adhesive, lamination, heat welding and / or stitching, or they can be integrated into a support structure that forms a flow control unit. Filter components may include pores for removing particulate matter from a first fluid flow, and flow control components may include one or more flow control passages that can be openings of the flow control components. In some embodiments, each flow control passage can independently be a hole, slit, perforation, flap, one-way valve or a combination thereof. In some embodiments, flow control passages can be opening ends of tubular flow control components. Generally, a filter assembly is tubular and includes tubular filter components and tubular flow control components. However, a filter assembly may also be flat and essentially two-dimensional, or substantially flat or two-dimensional in structure, and may include filter components of a flat and two-dimensional, or substantially flat or two-dimensional structure, and flow control components of a flat, essentially two-dimensional, or substantially flat or two-dimensional structure. The filter component has one end open and the other closed, and has a diameter approximately equal to the size of the support structure. The flow control component can be tubular, with one end open and the other closed, or it can have both ends open and have a diameter approximately equal to the size of the support structure. In some embodiments, the filter component is sized to allow friction fitting with the support structure, and in other embodiments, the filter component may be slightly larger than the support structure and attached to the support structure using fastening means. In some embodiments, the flow control component is also tubular, with one end open and the other closed. The flow control component is formed to be larger than the filter component. By making the diameter of the flow control component larger than the diameter of the filter component, the first fluid flow can "push" or "bend" the flow control component into the opening of the support structure, thereby allowing at least a portion of the first fluid flow to pass between the filter component and the flow control component.When the flow control component is tubular, the length of the flow control component corresponds to the total length of the filter assembly, and one end may be closed if necessary. In other embodiments, the length of the flow control component may be shorter than the length of the filter assembly, for example, the length of the flow control component may be in the range of 20% to 99.9% of the length of the filter assembly. In other embodiments, the length of the flow control component may be in the range of 25% to 99%, or 30% to 99%, or 33% to 99%, or 35% to 99%, or 40% to 99%, or 50% to 99%, or 55% to 99%, or 60% to 99%, or 65% to 99%, or 70% to 99%, or 75% to 99%, or 80% to 99%, or 85% to 99%, or 90% to 99%, or 95% to 99%. Even flow control components shorter than the length of the filter assembly can normalize the pressure along the length of the filter assembly during flow in a second direction.

[0107] In some embodiments, a flow control unit is formed by incorporating flow control components into a support structure. Specific embodiments of each of these components, i.e., flow control components and support structures, are described separately in this disclosure, and their respective characteristics and features are generally applicable herein, but flow control components can be incorporated into the support structure by various means. For example, a flow control unit can be formed by directly attaching the flow control components, in whole or in part, to the support structure using adhesive, lamination, welding, sewing, tack fastening, clamping, or other suitable mounting means. A flow control unit may have one or more layers.

[0108] Generally, flow control units can be manufactured from materials such as metals, plastics, synthetic fibers and / or natural fibers or combinations thereof. Synthetic fibers and / or natural fibers can be in the form of fabrics such as knits, woven fabrics, nonwoven fabrics or combinations thereof. Examples of nonwoven fabrics include any known nonwoven fabric forms such as spunbond nonwovens, meltblown nonwovens, needle-punched nonwovens, and felt nonwovens. Suitable synthetic fibers and / or natural fibers include, for example, polyamides, polyesters, polyurethanes, acrylics, methacrylics, aramids, copolymers thereof, cotton, wool, jute, sisal, bamboo, cellulose, or any combination thereof. In some embodiments, flow control units can be made from relatively flexible materials. In other embodiments, flow control units can be rigid, self-supporting structures. In other embodiments, flow control units can include a relatively rigid support structure and relatively flexible flow control components attached to or integrated with the support structure. Flow control units can be tubular or flat. A flow control unit may include one or more flow control passages that can be openings within the flow control unit. In some embodiments, each flow control passage may independently be a hole, slit, perforation, flap, one-way valve, or a combination thereof.

[0109] Alternatively, the flow control unit may include a monolithic structure, and the flow control unit may include parts with varying thickness, such as thick and thin sections. For example, the thick section may have a thickness of 100-150% of the average thickness of the flow control unit, and the thin section may have a thickness of 0.1-99% of the average thickness of the flow control unit. In a specific embodiment, the thin section may have a thickness of 1%-50%, or 10%-50%, or 10%-30%, or 10%-20% of the average thickness of the flow control unit, or any percentage thickness within the above range. Similarly, in a particular embodiment, the thick section may have a thickness of 100%-140%, or 100%-130%, 100%-120%, or 100-110% of the average thickness of the flow control unit, or any percentage thickness within the above range.

[0110] The flow control passages of the flow control unit may be formed during the manufacturing process of the flow control unit, or added to the flow control unit as an additional step. In some embodiments, the flow control unit may be manufactured by injection molding or by an additive manufacturing process.

[0111] For example, in a particular embodiment, the flow control unit may include regions of varying thickness. Depending on the configuration, the flow control unit may also include flow control passages. The regions of varying thickness can form patterns such as dots, ribbons, grids, or crosshatch patterns. For example, thicker ribbons may be oriented in any pattern, e.g., vertical, horizontal, i.e., circumferentially, or helically wound along the length of the flow control unit. For example, when ribbons are oriented vertically, the spacing between one ribbon and each adjacent ribbon takes the form of narrow slits. Similarly, if the thicker portions form a grid, the regions between the grid supports may be thinner portions.

[0112] In some embodiments, the thicker portion may be positioned to cover at least 50% of the area of ​​the flow control unit. In other embodiments, the thicker portion may be positioned to cover at least 60%, 70%, 80%, 90%, 95%, 97%, 98%, or 99% of the flow control unit. Similarly, the thinner portion may be positioned to cover at least 50% of the area of ​​the flow control unit. In other embodiments, the thinner portion may be positioned to cover at least 60%, 70%, 80%, 90%, 95%, 97%, 98%, or 99% of the flow control unit. The transition from the thicker portion to the thinner portion may be gradual or abrupt and may depend on the manufacturing method of the flow control unit.

[0113] When the flow control unit includes both thick and thin sections, during normal operation, i.e., during fluid flow in the first direction, the fluid passes through the filter component and then flows across and / or through the flow control unit if flow control passages are present, or along the flow control unit if flow control passages are not present. During the cleanup pulse, i.e., during fluid flow in the second direction, the thin section of the flow control unit expands outward and comes into contact with the filter component, and with all or substantially all flow control passages, if present, sealed, the fluid flow is converted into mechanical pressure, inducing or facilitating the cleaning of the filter component. Thus, this configuration utilizes the expanded state of the flow control unit during the cleanup pulse.

[0114] In another embodiment, a flow control unit may be formed by incorporating flow control components into a support structure. For example, the flow control unit can be formed by directly attaching the flow control components, in whole or in part, to the support structure using adhesive, lamination, welding, sewing, tack fastening, clamping, or other suitable mounting means. Thus, the flow control unit can be multilayered, for example, having two layers. The flexibility or rigidity of each layer may differ from that of the others; for example, the flow control unit includes a first layer (a relatively rigid layer) and a second layer (a more flexible layer compared to the first layer). Each layer of the multilayered structure may include flow control passages.

[0115] In more specific examples, during normal operation, a flow control unit may include a flexible material and flow control passages that remain open between the fluid flow in a first direction. The flow control passages can independently be holes, slits, perforations, flaps, one-way valves, or a combination thereof. For example, a flow control passage can be a flap. The number of individual flaps may depend on the size of the filter assembly, the size of the individual flaps, and the desired fluid flow rate / pressure in the second direction. Generally, the larger the individual flaps, the fewer individual flaps are required. In some embodiments, the individual flaps can be arranged in any pattern to cover at least 50% of the area of ​​the flow control unit. In other embodiments, the individual flaps can be arranged to cover at least 60%, or 70%, or 80%, or 90%, or 95%, or 97%, or 98%, or 99% of the inner portion of the filter component. During the cleanup pulse, the fluid flow in the second direction closes the flap, blocking all or substantially all of the airflow passing through the flow control unit, converting the air pressure into the mechanical motion of the flexible flow control unit. This mechanical motion induces movement of the filter components, removing particulate matter from the filter surface.

[0116] In yet another embodiment, the flow control unit may have one or more layers, for example, two layers. Generally, each layer in a multilayer flow control unit may be made from a material such as metal, plastic, synthetic fiber and / or natural fiber or a combination thereof. Synthetic fiber and / or natural fiber may be in the form of fabric, including, for example, knitted, woven, nonwoven, or a combination thereof. Examples of nonwoven fabrics include any known nonwoven fabric form such as spunbond, meltblown, needle-punched, or felted nonwoven fabric. Examples of suitable synthetic fiber and / or natural fiber include polyamide, polyester, polyurethane, acrylic, methacrylic, aramid, any copolymer thereof, cotton, wool, jute, sisal, bamboo, cellulose, or any combination thereof.

[0117] In some embodiments, the flow control components are integrated such that fluid can pass between the support structure (or first layer) and the fluid flow control components (second layer) during normal operation, or in other words, fluid can flow within the multilayer flow control unit. Each layer may independently include flow control passages, such as holes, flaps, or slits. The flow control passages within each layer may generally be arranged so that the flow control passages do not align between layers. In yet another embodiment, fluid can be prevented from passing essentially between the support structure and the flow control components, or in other words, fluid can not flow essentially within the multilayer flow control unit.

[0118] In some embodiments of the flow control unit, upon receiving a fluid flow in a first direction, the flow control components can be "pushed in" or "bent" into the internal space of the support structure. During a fluid flow in a second direction, the multilayer flow control unit expands outward, compressing at least a portion of the flow control components against the filter components and sealing all or essentially all of the flow control passages. Once all or essentially all of the flow control passages are sealed, the fluid flow is converted into mechanical pressure, inducing or facilitating the cleaning of the filter components. This configuration can effectively utilize the relaxed versus expanded state of the flow control unit during a cleaning pulse.

[0119] During normal operation, when exposed to a first fluid flow, the flow control component is in a relaxed state, allowing the first fluid flow to pass through the filter component, a portion of the first fluid flow to flow between the filter component and the flow control component, and another portion of the first fluid flow to flow through one or more flow control passages. Typically, the flow control component has a larger diameter compared to the diameter of the filter component. This allows the flow control component to be in a relatively relaxed state on the support structure, facilitating the flow of a portion of the fluid flow between the flow control component and the filter component. When relaxed, the flow control component can be pushed into any opening region of the support structure.

[0120] During pulses in the pulse jet cycle, the filter assembly expands outward into an expanded state, pressing the flow control component layer against the filter component layer, causing the flow control component layer to cover the filter component and block the permeability or pores of the filter component layer except in the areas of flow control passages or openings. In other words, during the clean cycle, the two layers of the filter assembly compress each other, blocking the permeability of passages outside or across the openings of flow control passages, or passages across the interface between the filter component and the flow control component. When a large or all of the surface area of ​​the flow control component is masked or blocked by the flow control component, the clean airflow pulse is redirected along the length of the filter assembly and converted into a more uniform mechanical motion, depending on the amount of flow control passages or openings that may be present within the flow control component. This more uniform mechanical motion can cause the filter component to expand more efficiently, and consequently induce more efficient cleaning of the filter component.

[0121] Figure 1 is a schematic diagram of a baghouse 100 according to an embodiment disclosed herein. As shown in Figure 1, the opposite direction is indicated by the arrow (t). The opposite direction may be the direction of the circumferential width of the filter assembly and may not be parallel to the length of the filter assembly, but in some embodiments may be perpendicular to the length of the filter assembly. As shown in the figure, the longitudinal direction is indicated by the line (L) and is the direction along the length of the filter assembly.

[0122] A baghouse can include multiple filter assemblies. In a typical baghouse (e.g., baghouse 100 in Figure 1), each filter assembly has a length of 0.3 m to 10 m and an inner diameter of 5 cm to 30 cm. The filter assemblies can have dimensions that allow them to be mounted in a baghouse, mounted on a support structure, or mounted to a support structure. These dimensions are not necessarily limiting for the purposes of this disclosure, and it should be understood that the embodiments disclosed herein can be used in a variety of baghouses. In one embodiment, the filter components of the filter assembly may be pleated. In some embodiments, pleated filter components can increase the filter area and thickness of the filter assembly, and at a given filter radius, the filter components can be exposed to a smaller amount of particulate matter per unit of filter area in the fluid compared to non-pleated filter components.

[0123] The filter assemblies of this disclosure may include flow control components that provide direction-dependent flow resistance to the filter assembly. This allows for easy and efficient cleaning of the filter assembly while simultaneously enabling the use of a filter assembly with higher permeability. The flow control components may be positioned downstream of the filter components during normal flow. The filter assemblies may have various shapes and features depending on the operation and cleaning technique. In one embodiment, a filter assembly for pulse jet cleaning has a cuff at one end and an opening at the other end, thereby allowing the filter assembly to at least partially enclose a support structure.

[0124] As shown in Figure 1, a baghouse 100 having a pulse jet cleaning sequence is shown. Inside the hopper 20, a fluid flow 21 containing particulate matter enters the hopper at the inlet 22 and passes through a filter assembly 23 having filter components. The filter components may include a filter medium made from woven felt, nonwoven felt, polyester, cotton, nylon, glass fiber material, catalytic filter material, porous membrane, adsorbent filter material or any combination thereof, and optionally a support structure.

[0125] In some embodiments, the filter component includes felt or fibers made from, for example, PTFE, polyester, polypropylene, polyphenylene sulfide, aramid, polyimide, or combinations thereof. In certain embodiments, the filter component may include mixed fibers and filaments containing glass fibers and PTFE. In some embodiments, the filter component includes a material capable of withstanding high-temperature applications exceeding 400°C. This material may be woven PTFE, glass fibers, or polyimide. In some embodiments, the filter component of the filter assembly 23 may include one or more porous membranes to provide high fluid flow rate and good dust cake discharge. The porous membrane can be attached to the filter component using adhesive, lamination, welding, sewing, tack fastening, clamping, or other suitable mounting means. In some embodiments, the porous membrane may include a polymer (e.g., a fluoropolymer). In some embodiments, the porous membrane may include ePTFE.

[0126] Returning to Figure 1, the tube sheet 25 in the hopper 20 prevents the fluid flow 21 from bypassing the filter assembly 23. The filter assembly 23 may include an internal support structure 26 in the form of a cage. The filtered fluid flow 24 passes through the filter assembly 23 and exits through the bag outlet 29, then exits the clean air compartment at outlet 27. During operation, granular material forms a dust cake 28 on the outside of the filter component, as shown in the bag on the left side of the figure. Once cleaning is performed to remove the dust cake 28, air from the pulse pipe 30 enters the filter assembly. Pulses 32 of this air traveling along the longitudinal direction (L) expand the filter assembly 23, loosen the dust cake, and collect the granular material 31 at the bottom of the hopper 20.

[0127] In some embodiments, the fluid flow 21 containing particulate matter is the first fluid flow, and the air pulse 32 is the second fluid flow, and the first and second fluid flows can be different. In certain embodiments, for example, when the second fluid flow is a reverse airflow, the first and second fluid flows can be the same. In other embodiments of reverse airflow, the first and second fluid flows are different.

[0128] As seen in the bag on the right in Figure 1, the pulse jet expands the filter assembly. Repeated expansion and contraction of the filter assembly causes wear. It should be understood that other cleaning techniques also put stress on the filter assembly. The advantages of the filter assembly described herein include, at a minimum, 1) having directional flow resistance, 2) providing the filter assembly with a more uniform pressure distribution along its length, and 3) providing the filter assembly with a higher, more uniform pressure distribution along its length.

[0129] In some embodiments, the baghouse 100 may include a tube sheet disposed between an inlet 22 and an outlet 27 in a housing (e.g., a hopper 20), and one or more filter assemblies attached to the tube sheet according to the embodiments disclosed in the present disclosure.

[0130] In a baghouse (e.g., the baghouse 100 of FIG. 1), filter components should be able to withstand high temperatures without degradation. Depending on the chemical content and / or moisture content of the fluid stream, its temperature and other conditions, filter components may be constructed from filter media including, for example, fiberglass, polyester, cotton, nylon or other materials. Felts and fibers made from PTFE, polyester, polypropylene, polyphenylene sulfide, aramid, polyimide or combinations thereof may also be used as filter media for filter components. Mixtures of fibers and filaments such as fiberglass and PTFE may also be used as filter components. For example, for high-temperature applications exceeding 400°C, woven PTFE, fiberglass or polyimide may be used as filter components.

[0131] In some embodiments, the filter component may be a commercially available fabric, such as felt. These felts have a weight of 300 to 1200 grams per square meter (g / m 2 ), or 400 to 1100 g / m 2 , or 500 to 1000 g / m 2 , or 650 to 900 g / m 2 . The felt may have a weight of 100 to 250 g / m 2 , or 110 to 240 g / m 2 , or 120 to 230 g / m 2 , or 130 to 210 g / m 2It can be reinforced with multifilament woven scrim of a certain weight. The scrim elements can be made from any polytetrafluoroethylene (e.g., drawn polytetrafluoroethylene or porous polytetrafluoroethylene). Felt is manufactured from staple fibers and can have lengths of about 1 cm to about 30 cm, or about 2 cm to about 28 cm, or about 3 cm to about 26 cm, or about 4 cm to about 24 cm, or about 5 cm to about 22 cm, or lengths that fall within these ranges. In some embodiments, felt can be made from staple fibers of denier / filament of about 1 to about 20 denier / filament, or about 2 to about 18 denier / filament, or about 3 to about 16 denier / filament, or about 4 to about 14 denier / filament, or about 5 to about 12 denier / filament, or about 6 to about 10 denier / filament, or denier / filament that fall within those ranges. In some embodiments, the felt may be made from PTFE felt, polyester felt, aramid felt, polypropylene felt, polyphenylene sulfide felt, polyimide felt, or a combination of these polymers. In some cases, these felts may further contain one or more glass fibers, metal fibers, or a combination thereof.

[0132] In one embodiment, an additional layer may be added to the filter component, such as a wrap or adsorbent component made of nonwoven polypropylene material, to capture mercury, other heavy metals, volatile organic compounds (VOCs), or any other desired components filtered downstream of the filter component. In another embodiment, the filter component may include one or more catalysts. For example, the catalyst may be NO x It can be suitable for converting pollutants such as NH3, CO, dioxins, furan, or ozone. The catalyst can contain active materials such as TiO2, V2O3, V2O5, WO3, MnO2, Pt, and Al2O3. By using the catalyst, dioxins, furan, NO x This allows for the effective removal of pollutants such as CO from the fluid flow.

[0133] Figure 2A is a schematic diagram of the forward flow (also referred to herein as "normal flow") of a filter assembly 200 for use in a conventional pulse jet baghouse. Figure 2B is a schematic diagram of the clean pulse flow (also referred to herein as "counter-flow") of a filter assembly for use in a conventional pulse jet baghouse.

[0134] As illustrated, the filter assembly 200 may include a filter component 202 having a filter medium and, optionally, a porous membrane (not shown) attached to the filter medium. The filter assembly 200 may include a support structure 204. The support structure 204 available for use with the filter assembly 200 can vary considerably depending on many conditions, including the configuration of the filter assembly 200, the type of material to be filtered, the filtration system into which the filter assembly 200 is incorporated, the purification mechanism, and so on. For example, a suitable support structure 204 may include a cage, ring, or brace that can be manufactured from materials such as metal, plastic, and natural fibers, and may include woven or nonwoven forms such as spunbond polyester or nonwoven aramid felt material. In one embodiment, the support structure 204 may be a metal or plastic mesh. A wire support cage may also be used as a support structure. In some embodiments, the support structure 204 may be made from a relatively flexible material. In other embodiments, the support structure 204 may be a rigid self-supporting structure. The filter component 202 is typically in contact with the support structure 204, thereby holding the filter component 202 relatively rigidly, which minimizes, but does not completely eliminate, bending, twisting, and torsion in the direction of the filter assembly.

[0135] In one embodiment, the support structure 204 may be configured as a single integrated part or may include a cage that can be assembled from multiple parts. The cage may have a cover (not shown) to provide a barrier, and the cover is provided between the support structure 204 and the filter component 202. The cover can reduce contact between the filter component 202 and the support structure 204.

[0136] During normal operation, the fluid flow 206A passing through the filter assembly 200 is in the first direction. As shown in Figure 2A, when particles or particulate matter in the fluid flow are collected by the filter component, a dust cake 208 can accumulate on the filter component 202. During a pulse jet cleaning cycle, an air pulse or airflow 206B may flow through the filter assembly 200 in a second direction. The first direction of the fluid flow 206A may be opposite to the second direction of the air pulse or airflow 206B.

[0137] In some embodiments, one or more pressure gauges 210a-d may be positioned along the longitudinal direction 212 to measure the pressure of the pulsed flow distributed along the length of the filter assembly 200. It is readily apparent that the pressures measured by each pressure gauge 210a-d will be relatively low because the filter assembly 200 is exposed to a longitudinal pulsed flow along the length of the filter assembly 200, which will be explained in more detail below.

[0138] Figures 3A–3D are schematic diagrams of a filter assembly 300 for use in a pulse jet baghouse in normal and counterflow, according to embodiments disclosed herein. As shown, the filter assembly 300 may include a filter component 302a and a flow control component 306a. The filter component 302a may include a filter medium and optionally a porous membrane (not shown) attached to the filter medium. The filter assembly 300 may also include a support structure 304. The filter assembly 300 can be used to filter particulate matter 307a–307d from a fluid flow 308.

[0139] The filter assembly 300 further includes a flow control component 306a. The flow control component 306a can withstand structural failure caused by the stress of propagating cleanup pulses that cause the flow control component to expand and mask the surface of the filter component 302a. In some embodiments, the flow control component 306a may include a sheet material. In certain embodiments, the sheet material may be non-porous. In some embodiments, the sheet material may be air-impermeable. In certain embodiments, the non-porous sheet material may be air-impermeable. In some embodiments, the sheet material may include metals (e.g., aluminum, stainless steel, and copper) or polymer non-porous films.

[0140] In some embodiments, the flow control component 306a is a tubular component with one end closed and the other end open. Alternatively, the flow control component 306c may have both ends open. The flow control component 306a can be placed on top of the support structure 304. Then, by placing the filter component 302a on top of the flow control component 306a, the support structure 304 becomes the innermost element, and the flow control component 306a is positioned between the support structure 304 and the filter component 302a. The flow control component 306a can be a relatively loose fit component compared to the filter component 302a. In this way, the flow control component 306a allows at least a portion of the first fluid flow 308a to flow between the flow control component 306a and the filter component 302a when operating in a first direction or normal direction. Furthermore, when exposed to the first fluid flow, the flow control component can be "pushed in" or "bent" into the space between the support elements of the support structure 304 by the pressure exerted by the first fluid flow 308a, thereby forming a space 301 between the flow control component 306a and the filter component 302a. The space 301 can be a distance d that can be varied depending, for example, the inflow pressure of the fluid flow 308a, the relative degree of slack of the flow control component 306a compared to the filter component 302a, and the flexibility of the flow control component 306a.

[0141] During normal flow, as indicated by the arrows in Figure 3A, the fluid flow 308a flows through the filter component 302a in a first direction (e.g., the normal direction), and then moves through the space or distance 301 between the filter component 302a and the flow control component 306a. As particulate matter or granular material from the fluid flow is collected by the filter component 302a, as shown in Figure 3A, a dust cake, i.e., granular matter 307a, may accumulate on the filter component 302a. The space 301 is formed by the distance d between the flow control component 306a and the filter component 302a. In embodiments in which the flow control component 306a includes an air-impermeable and / or non-porous sheet-like material, the fluid flow 308a passes through the filter component 302a but not through the flow control component 306a. The cleaned fluid flow 310 flows longitudinally along the space 301.

[0142] As indicated by the arrows in Figure 3B, during a counterflow or pulse jet cleaning pulse, the second fluid flow 308b flows in a second direction opposite to the normal direction shown in Figure 3A. In embodiments in which the flow control component 306b includes an air-impermeable and / or non-porous sheet-like material, the fluid flow 308b does not penetrate the flow control component 306b. Therefore, the second fluid flow 308b induces an expansion and masking motion of the flow control component 306b, causing a pressure pulse toward the filter component 302b, releasing the particulate matter 307b collected from the upstream surface 312 of the filter component 302b, thus cleaning the upstream surface 312 of the filter component.

[0143] Figure 3C shows an embodiment in which the flow control component 306c is open at both ends. As indicated by the arrows in Figure 3C, the second fluid flow 308c flows in a second direction opposite to the normal direction shown in Figure 3A. In the embodiment in which the flow control component 306c comprises an air-impermeable and / or non-porous sheet-like material and is open at both ends, the fluid flow 308c does not penetrate the flow control component 306c. Therefore, the second fluid flow 308c induces expansion and masking motion of the flow control component 306c, causing a pressure pulse toward the filter component 302c, releasing the granular material 307c collected from the upstream surface 312 of the filter component 302c, thus cleaning the upstream surface 312 of the filter component.

[0144] Figure 3D shows an embodiment in which the flow control component 306d is open at both ends and the length of the flow control component is shorter than the length of the filter assembly 300. For example, as shown by the dotted line in Figure 3D, the length of the flow control component 306d can be about 30%, 50%, or 75% of the length of the filter assembly. As shown by the arrow in Figure 3D, the second fluid flow 308d flows in a second direction opposite to the normal direction as shown in Figure 3A. In embodiments in which the flow control component 306d comprises an air-impermeable and / or non-porous sheet-like material and is open at both ends, the fluid flow 308d does not penetrate the flow control component 306d. Thus, the second fluid flow 308d induces an expansion and masking action of the flow control component 306d, causing a pressure pulse toward the filter component 302d to release the collected particulate matter 307d from the upstream surface 312 of the filter component 302d, thus cleaning the upstream surface 312 of the filter component.

[0145] In some embodiments, a filter assembly 300 having a flow control component 306 may have a directional flow resistance that, when exposed to a fluid flow, has a first flow resistance in a first direction and a second flow resistance in a second direction. The first direction (e.g., the normal direction) may be the filtering direction when the fluid is in a normal flow (first fluid flow), while the second direction may be the opposite direction to the first, such as a counterflow or pulsed jet cleaning pulse (second fluid flow).

[0146] Figure 4A is a schematic cross-sectional view along the length of a filter assembly 400 for use in a pulse jet baghouse according to embodiments disclosed herein. Figures 4B–4D are schematic horizontal cross-sectional views of the filter assembly in normal and counter-fluid flow for use in a pulse jet baghouse according to embodiments disclosed herein. The filter assembly 400 can be used to filter particulate matter from a fluid flow and is purifiable (e.g., backflow air, shaker, and pulse jet).

[0147] Figure 4A shows a cross-sectional view of a filter assembly 400 having a filter component 404, a support structure 408, and a flow control component 406a positioned downstream of the filter component 404 and between the filter component 404 and the support structure 408. The filter component 404 has a filter medium and optionally a porous membrane (not shown) attached to the filter medium. The flow control component 406a includes a plurality of flow control passages or openings 410 distributed along the sides of the flow control component material and optionally along the bottom. In some embodiments, the filter assembly 400 having the flow control component 406a may have a directional flow resistance having a first flow resistance in a first direction and a second flow resistance in a second direction when exposed to a fluid flow. The first direction may be during filtration when the fluid flow 402a is in normal flow.

[0148] In some embodiments, the flow control component 406a is a tubular component with one end closed and the other end open, and includes one or more flow control passages or openings 410. The flow control component 406a can be placed on a support structure 408. Then, the filter component 404 can be placed on top of the flow control component 406a, so that the support structure 408 becomes the innermost element and the flow control component 406a is between the support structure 408 and the filter component 404. The flow control component 406a can be a relatively loose fit component when compared to the filter component 404. In this way, the flow control component 406a allows at least a portion of the first fluid flow 402a to flow through the space between the flow control component 406a and the filter component 404 when operating in a first direction or normal direction. Another portion of the purified fluid flow 403a can pass through one or more flow control passages or openings 410 of the flow control component 406a. When exposed to the first fluid flow 402a, the flow control component can be "pushed in" or "bent" into the space between the support elements of the support structure 408 by the pressure exerted by the first fluid flow 402a, thereby forming a space 401 between the flow control component 406a and the filter component 404. The space 401 can be a distance d that can vary depending, for example, the inflow pressure of the fluid flow 402a, the relative looseness of the flow control component 406a compared to the filter component 404, and the flexibility of the flow control component 406a.

[0149] During normal flow, as indicated by the arrows in Figure 4A, at least a portion of the fluid flow 402a passes through the filter component 404, then at least a portion passes through the space or distance 401 between the filter component 404 and the flow control component 406a, and then finally passes through the flow control component 406a. The space 401 is formed by the distance d between the flow control component 406a and the filter component 404. When the flow control component 406a includes a plurality of openings 410, another portion of the fluid flow 402a passes through the openings 410 and then through the flow control component 406a. Thus, the purified fluid flow 403a flows partially along the space 401 and partially longitudinally along the internal space of the flow control component 406a and the support structure 408.

[0150] The flow control component 406a can withstand structural failure caused by the stress of the propagating cleanup pulse, which causes the flow control component 406a to expand and mask against the surface of the filter component 404. The expansion and masking action of the flow control component 406a generates a pressure pulse directed toward the filter component 404, releasing the particulate matter collected from the upstream surface of the filter component 404, thereby cleaning the upstream surface of the filter component. In other words, the flow control component 406a manages the pressure stress of the cleanup pulse while the filter component 404 expands and releases the collected particulate matter.

[0151] Referring here to Figures 4B-4D, in some examples, the filter component 404 encloses the support structure 408 at least partially. In some embodiments, as shown in Figures 4B-4D, the flow control component 406 may include at least one flow control passage or opening 410. The flow control component 406 can adjust the amount of fluid flowing through the filter component 404 by changing the surface area of ​​the filter component 404 exposed to the fluid flow, based on the direction of the fluid flow. In some examples, as shown, for example, in Figures 4A-4D, the at least one flow control passage or opening 410 may include openings such as holes, slits, perforations, flaps, one-way valves, or combinations thereof.

[0152] In some embodiments, the flow control component 406 may be a membrane containing one or more holes, slits, perforations, flaps, one-way valves, or a combination thereof. In other embodiments, the flow control component 406 may include a sheet-like metal material having one or more holes, slits, perforations, flaps, one-way valves, or a combination thereof. In yet another embodiment, the flow control component may be a combination of a membrane and one or more metal reinforcements, further including one or more holes, slits, perforations, flaps, one-way valves, or a combination thereof. The flow control components 406a-d may be mounted so as to be between the support structure 408 and the filter component 404. In other embodiments, the flow control component may be mounted inside the support structure 408, i.e., on the side of the support structure 408 not adjacent to the filter component 404.

[0153] In some embodiments, as shown for example in Figures 4A-4C, the fluid flow 402a-b is in a first direction (e.g., the normal direction), the flow control components 406a-c are in a relaxed state, and the outer surface of the flow control components 406a-c has 0% to 99% contact with the inner surface of the filter component 404. In some embodiments, the contact between the flow control components 406a-c and the filter component 404 can be in the range of about 0% to about 90%, or about 0% to about 80%, or about 0% to about 70%, or about 0% to about 60%, or about 0% to about 50%, or about 0% to about 40%, or about 0% to about 30%, or about 0% to about 20%, or about 0% to about 10%, or the contact can be in a range that falls within these ranges.

[0154] In certain embodiments, the flow control component 406 can come into contact with the filter component 404 by being bonded to it. In some embodiments, the flow control component 406 can be attached to or bonded to the filter component 404 (for example, by welding, or using stitches, adhesive dots, or adhesive lines). In some embodiments, the flow control component 406 can cover at least a large portion of the filter component 404.

[0155] The relaxed state can also be called the “unmasked” state, because the flow control components 406a-c do not cover / mask, or only partially cover, the inner surface region of the filter component 404. In some embodiments, in the unmasked or relaxed state, the flow control components 406a and the filter component 404 can come into contact with each other in regions corresponding to elements of the support structure 408. That is, the support structure 408 friction-fits the flow control components 406a and the filter component 404, thus providing a relatively close fit between the support structure 408, the flow control components 406a, and the filter component 404. In regions where the support structure 408 does not directly contact the flow control components 406a, a portion of the flow control components 406a can come into direct contact with the filter component 404, a portion of the flow control components 406a can be separated from the filter component 404 by space 401 and distance d, or both.

[0156] In the relaxed state, for example, the distance d between a point on the outer surface of the flow control component and the inner surface of the filter component may be in any of the following ranges: 0.0 to approximately 100 mm, or approximately 0.001 to approximately 100 mm, or approximately 0.002 to approximately 95 mm, or approximately 0.003 to approximately 90 mm, or approximately 0.004 to approximately 85 mm, or approximately 0.005 to approximately 80 mm, or approximately 0.006 to approximately 75 mm, or approximately 0.007 to approximately 70 mm, or approximately 0.008 to approximately 65 mm, or approximately 0.009 to approximately 60 mm, or approximately 0.01 to approximately 55 mm.

[0157] In some embodiments, as shown in Figure 4C for example, the fluid flow may be in the process of changing direction, and the flow control component 406c may remain in a relaxed state, with at least a portion of the flow control component 406c in contact with the inner surface of the filter component 404. While a portion of the flow control component 406c may be in contact with the filter component 404 when relaxed, there is no pressure between the flow control component 406c and the filter component 404 in the relaxed state.

[0158] In some embodiments, as shown, for example in Figure 4D, the fluid flow 402d is in a second direction (e.g., opposite to the normal direction), the flow control component 406d is in an extended state, and the outer surface of the flow control component 406d is in contact with the inner surface of the filter component 404. The second direction of the second fluid flow 402d can be opposite to the first direction of the first fluid flow 402a-b. In some embodiments, the fluid flow 402d can be a reverse airflow, which may be the same as or different from the fluid flows 402a-c. In some embodiments, the fluid flow 402d can be a pulse jet airflow, which may be different from the fluid flows 402a-c. In some embodiments, the fluid flow 402d is a filtered fluid flow with a different composition from the fluid flows 402a-c, which are unfiltered and therefore contain a large amount of particulate matter. In some embodiments, the fluid flow 402d is in a different direction from the fluid flows 402a-c (e.g., opposite direction).

[0159] The expanded state is also called the “masking” state because the flow control component 406d masks or covers at least a portion of the inner surface area of ​​the filter component 404 that is exposed to the fluid flow 402d. The flow control component 406 can alternate between a relaxed, unmasked state and an expanded, masked state with respect to the filter component 404.

[0160] In some embodiments, a filter assembly having a flow control component 406 may have a directional flow resistance when exposed to a fluid flow, having a first flow resistance in a first direction and a second flow resistance in a second direction. As the average size or number of flow control passages or openings 410 decreases, the difference between the first and second flow resistances increases, and the second flow resistance becomes greater than the first flow resistance. The increase in the difference between the first and second flow resistances is due to the flow control component masking a wider area of ​​the inner surface of the filter component, thereby reducing the surface area of ​​the filter component 404 exposed to the fluid flow.

[0161] In some cases, the ratio of the first flow resistance to the second flow resistance is in the range of less than 0.01% to about 99%, or about 0.1% to about 99%, or about 0.5% to about 99%, or about 1% to about 99%, or about 2% to about 95%, or about 3% to about 90%, or about 4% to about 85%, or about 5% to about 80%, or about 6% to about 75%, or about 7% to about 70%, or about 8% to about 65%, or about 9% to about 60%, or about 10% to about 55%, or less than 0.01% to about 50%, or about 0.1% to about 50%, or about 0.5% to about 50%.

[0162] In this embodiment, the flow control passage 410 has an average opening size of approximately 0.0001 to approximately 100,000 mm. 2 , or approximately 0.001 to approximately 80,000 mm 2 Approximately 0.01 to 60,000 mm 2 Approximately 0.1 to 40,000 mm 2 Approximately 1 to 30,000 mm 2 Approximately 2 to 20,000 mm 2 Approximately 3 to 10,000 mm 2 Approximately 4 to 8,000 mm 2 Approximately 5 to 6,000 mm 2 Approximately 6 to 4,000 mm 2 Approximately 7 to 2,000 mm 2 Approximately 8 to 1,000 mm 2 Approximately 9 to 500 mm 2 , about 10~200mm 2 Alternatively, the opening may have an opening size whose average opening size falls within these ranges.

[0163] In the embodiment, the flow control passage 410 may have a slit having a length of more than 0 to about 10 m, or about 0.1 to about 9.5 m, or about 0.2 to about 9.0 m, or about 0.3 to about 8.5 m, or about 0.4 to about 8.0 m, or about 0.5 to about 7.5 m, or about 0.6 to about 7.0 m, or about 0.7 to about 6.5 m, or about 0.8 to about 6.0 m, or about 0.9 to about 5.5 m, or about 1.0 to about 5.0 m.

[0164] In some examples, a fluid flow passing through a flow control component at a first velocity greater than 0.001 m / s in the first direction experiences a first flow resistance of less than approximately 33 mins / m, or less than approximately 30 mins / m, or less than approximately 27 mins / m, or less than approximately 24 mins / m, or less than approximately 21 mins / m, or less than approximately 18 mins / m, or less than approximately 15 mins / m, or less than approximately 12 mins / m, or less than approximately 9 mins / m, or less than approximately 6 mins / m.

[0165] In some cases, a fluid flow passing through a flow control component in the second direction at a second velocity of less than 0.05 m / s experiences a second flow resistance of approximately 0.08 min / m, or approximately 0.09 min / m, or approximately 0.1 min / m, or approximately 0.11 min / m, or approximately 0.12 min / m, or approximately 0.13 min / m, or approximately 0.14 min / m, or approximately 0.15 min / m, or approximately 0.16 min / m, or approximately 0.17 min / m.

[0166] Figures 5A-5B are schematic cross-sectional views along the length of a filter assembly 500 in normal flow and counterflow for use in a pulse jet baghouse according to embodiments disclosed herein. Figures 5C-5D are schematic horizontal cross-sectional views of a filter assembly 500 in normal flow and counterflow for use in a pulse jet baghouse according to embodiments disclosed herein. The filter assembly 500 can be used to filter particulate matter from a fluid flow 502.

[0167] In some embodiments, the filter assembly 500 may include a filter component 504, a support structure 508, and a flow control component 506a positioned between the filter component 504 and the support structure 508. In some examples, the filter component 504 encloses the support structure 508 at least partially. In some embodiments, as shown, for example, in Figures 5C-5D, at least a portion of the outer surface of the flow control component 506 is in contact with the inner surface of the filter component 504. The flow control component 506 may include at least one flow control passage 510. In some embodiments, the flow control component 506 may include a plurality of flow control passages 510. The plurality of flow control passages 510 can be selected from openings such as holes, slits, flaps, one-way valves, or combinations thereof. The openings can be of various geometric shapes (e.g., circles, ellipses, triangles, or rectangles).

[0168] In some embodiments, the flow control component 506a includes one or more flow control passages 510a and one or more flaps 512a, and the flow control component 506a is a tubular component with one end closed and the other end open. Alternatively, the flow control component may be open at both ends. The flow control component 506a can be placed on a support structure 508. Then, a filter component 504 can be placed on top of the flow control component 506a, so that the support structure 508 becomes the innermost element and the flow control component 506a is between the support structure 508 and the filter component 504. The flow control component 506a can be a relatively loose fit component when compared to the filter component 504. In this way, the flow control component 506a allows at least a portion of the first fluid flow 502a to pass between the flow control component 506a and the filter component 504 and flow when operating in a first direction or normal direction. Another portion of the first fluid flow 502a passes through one or more flow control passages or openings 510a, opening one or more flaps 512a and causing the flow control component 506a to be in an open position. When exposed to the first fluid flow 502a, the flow control component can be “pushed” or “bent” into the space between the support elements of the support structure 508 by the pressure exerted by the first fluid flow 502a, thereby forming a space 501 between the flow control component 506a and the filter component 504. The space 501 can be a distance d that can vary depending, for example, the inflow pressure of the fluid flow 502a, the relative looseness of the flow control component 506a compared to the filter component 504, and the flexibility of the flow control component 506a. In Figure 5B, when the flow control component 506b moves in the opposite direction and is exposed to a second fluid flow 502b, one or more flaps 512b are pushed into a closed position (for example, shown as a closed flow control passage 510b), limiting the amount of the second fluid flow 502b that can flow through one or more flow control passages or openings 510.

[0169] In some embodiments, the flow control passage 510 may include one or more flaps 512, as shown, for example, in Figures 5A–5D. The flow control component 506 may have a % opening area of ​​about 0.01% to about 50%, or about 0.02% to about 48%, about 0.03% to about 46%, about 0.04% to about 44%, about 0.05% to about 42%, about 0.06% to about 40%, about 0.07% to about 38%, about 0.08% to about 36%, about 0.09% to about 34%, about 0.10% to about 32%, about 0.11% to about 30%, or about 0.12% to about 28% compared to the total area of ​​the flow control component. The % opening area as used herein is determined by the % opening area of ​​the flow control component. The % opening area can be determined by dividing the total opening area of ​​the openings of the flow control component by the total area of ​​the flow control component. If one or more openings are in the shape of flaps, the area of ​​each opening is determined as if the material for each flap were absent.

[0170] In some embodiments, when the % opening area of ​​the flow control component is 0.0% to 50% of the total surface area of ​​the flow control component, the surface area of ​​the filter component exposed to the second fluid flow is reduced by 50% to 100%, or 50% to 99.99%. In some embodiments, as the % opening area of ​​the flow control component decreases, the difference between the first flow resistance and the second flow resistance increases. In other words, the smaller the % opening area on the flow control component, the greater the difference between the first flow resistance and the second flow resistance.

[0171] In certain embodiments, the flow control component 506 may be located in an internal region of the filter component 504 (e.g., downstream of the first fluid flow). In some embodiments, the flow control component 506 can reduce the total flow rate in the second direction 502d passing through the filter component 504 by more than 50% compared to a filter component without the flow control component. In some embodiments, the flow control component 506 can reduce the total flow rate in the second direction 502d passing through the filter component 504 by more than 55%, or more than 60%, or more than 70%, or more than 80%, or more than 90%, or more than 95%, or more than 99% compared to a filter component without the flow control component.

[0172] The distance (d) between a point on the outer surface of the flow control component 506 and the inner surface of the filter component 504 may be approximately 0 to approximately 100 mm, or approximately 0.001 to approximately 90 mm, or approximately 0.005 to approximately 80 mm, or approximately 0.01 to approximately 70 mm, or approximately 0.1 to approximately 60 mm, or approximately 0.2 to approximately 50 mm, or approximately 0.5 to approximately 40 mm, or approximately 1.0 to approximately 30 mm, or approximately 2.0 to approximately 20 mm, or approximately 3.0 to approximately 10 mm, or any distance that falls within these ranges.

[0173] The flow control component 506 can mask or cover the inner surface of the filter component 504, thereby reducing the surface area of ​​the filter component exposed to the second fluid flow by approximately 10 to 100%, or approximately 12 to 98%, or approximately 14 to 96%, or approximately 16 to 94%, or approximately 18 to 92%, or approximately 20 to 90%, or approximately 22 to 88%, or approximately 24 to 86%, or approximately 26 to 84%, or approximately 28 to 82%, compared to a filter component without the flow control component, or it can reduce the surface area of ​​the filter component exposed to the second fluid flow by a percentage within these ranges.

[0174] In some embodiments, as shown, for example in Figure 5A or Figure 5C, the fluid flow 502a or 502c is oriented in a first direction (e.g., the normal direction), and the flow control component 506a or 506c, which includes one or more flaps 512, is in a relaxed open state, and the one or more flaps 512 do not cover the plurality of flow control passages 510a or 510c. The fluid flow 502a or 502c passing through the flow control passages 510a or 510c at the first velocity experiences a first flow resistance. In some embodiments, the first fluid flow passes through the filter assembly at a velocity in the range of 0.1 m / min to 5 m / min. In other embodiments, the first fluid flow flows through the filter assembly at a velocity in the range of 0.2 m / min to 4 m / min, or 0.25 m / min to 3.5 m / min, or 0.25 m / min to 3 m / min, or 0.3 m / min to 3 m / min, or 0.3 m / min to 2.5 m / min, or 0.25 m / min to 2.5 m / min, or 0.25 m / min to 2.4 m / min.

[0175] In some embodiments, as shown, for example in Figure 5B or Figure 5D, the fluid flow 502b or 502d is directed in a second direction (e.g., the opposite direction to the normal direction), the flow control component 506b or 506d is in a masked closed state, and one or more flaps 512 cover at least a portion of the plurality of flow control passages 510b and 510d. In some embodiments where the flow control component 506 is fluid-permeable, the fluid flow 502b or 502d passes through the flow control component 506b or 506d in the second direction at a second velocity and experiences a second flow resistance at a lower velocity than in the first direction. In some embodiments where the flow control component 506 is fluid-impermeable, when the fluid flow flows in the second direction, the fluid flow 502b or 502d does not pass through the flow control passage 510b or 510d because the flow control component 506b is in a closed state.

[0176] In some embodiments, the first flow resistance is different from the second flow resistance. In an exemplary embodiment, the first flow resistance is smaller than the second flow resistance.

[0177] A filter assembly including a flow control component, as shown in Figures 3 to 5, can adjust the amount of the second fluid flowing through the filter component by changing the surface area of ​​the filter component exposed to the second fluid flow. In some embodiments, when the filter assembly is exposed to the second fluid flow in a second direction, the pressure within the filter assembly increases compared to the same second fluid flow without the flow control component. In further embodiments, when the filter assembly is exposed to the second fluid flow in a second direction, the flow control component can reduce the flow rate of the second fluid flowing through the filter assembly, thereby increasing the pressure within the filter assembly. As used herein, the phrase “within the filter assembly” means the downstream side of the filter assembly when the fluid flow is in the first direction. Also, the increase in pressure within the filter assembly is relative to the same filter assembly under the same second fluid flow pressure when the filter assembly does not include the flow control component. As used herein, the increase in pressure within the filter assembly can be measured in one or more ways. For example, at least three sensors arranged relatively evenly along the longitudinal axis of the filter assembly can measure the pressure along the length of the filter assembly. The pressure increase can be expressed as the difference in the area under pressure curve (i.e., Figure 10). In another embodiment, the pressure increase can be measured as the increase in at least one pressure measurement along the longitudinal axis of the filter assembly compared to the pressure measurement without the flow control component (i.e., Figures 9A, 9B, or 9C). In yet another embodiment, as shown in Figure 10, the pressure increase is more uniform compared to the same filter assembly without the flow control component when comparing the pressure differences at at least three points along the longitudinal axis of the filter assembly, i.e., Example 6, to the comparative example without the flow control component.

[0178] Figures 6A-6B are schematic cross-sectional views of an exemplary filter assembly 600 used in a reverse air filter according to an embodiment of the present disclosure.

[0179] The filter assembly 600 can be used to filter particulate matter from a fluid flow 602. In some embodiments, the filter assembly 600 may include a filter component 604, a support structure 608, and a flow control component 606 located downstream of the filter component 604 in the forward direction, and positioned outside both the filter component 604 and the support structure 608. The support structure 608 may consist of multiple support rings. The particulate matter collected from the fluid flow 602 can form a dust cake 28 inside the filter component 604.

[0180] In some examples, the filter component 604 encloses the support structure 608 at least partially. In some embodiments, the flow control component 606 may include a flow control passage. The flow control passage may include an opening (see, for example, Figure 4), a flap (see, for example, Figure 5), or a one-way valve.

[0181] In some embodiments, the flow control component may include one or more individual tabs made of porous or non-porous sheet material. The individual tabs can be attached to the inner portion of the filter component (302a, 404, 504) such that only a portion of each individual tab is attached to the filter component. The attachment portion is oriented so that the unattached portion of each individual tab can move freely during flow in a first direction, for example, the tab can move away from the filter component so as not to obstruct the flow. When the flow is in a second direction, the tab can move toward the filter component and obstruct the outward flow of the fluid. For example, in a vertically oriented filter assembly, if the clean fluid flow enters the filter assembly from the top of the assembly and flows downward, the individual tabs can be attached only to the top of each tab. When the fluid flows in a first direction, the unattached portion of the individual tab can move away from the fluid flow. In a second direction, the unattached portion of the individual tab is pressed against and in contact with the filter component, so that the fluid moving in the second direction cannot be discharged out of the filter assembly by the individual tab.

[0182] The number of individual tabs may depend on the size of the filter assembly, the size of the individual tabs, and the desired fluid flow rate / pressure in the second direction. Generally, the larger the individual tabs, the fewer individual tabs are required. In some embodiments, the individual tabs may be arranged in any pattern and may be positioned to cover at least 50% of the area of ​​the inner portion of the filter component. In other embodiments, the individual tabs may be positioned to cover at least 60%, 70%, 80%, 90%, 95%, 97%, 98%, or 99% of the inner portion of the filter component.

[0183] In another embodiment, the flow control component may include one or more ribbons. The ribbons can be wound in any pattern, for example, vertical, horizontal, i.e., circumferentially, or helically along the length of the filter component. For example, when the ribbons are oriented vertically, the spacing between one ribbon and each adjacent ribbon can function as the aforementioned slits. Similarly, when the ribbons are oriented circumferentially, the spacing between each ribbon can function as the aforementioned slits. Likewise, when the ribbons are wound helically around the inner portion of the filter component, the spacing between each adjacent winding of the helix can function as the aforementioned slits. In some embodiments, the ribbons may be arranged to cover at least 50% of the area of ​​the inner portion of the filter component. In other embodiments, the ribbons may be arranged to cover at least 60%, 70%, 80%, 90%, 95%, 97%, 98%, or 99% of the inner portion of the filter component.

[0184] This disclosure also relates to a baghouse filter system comprising a housing having an inlet and an outlet, a tube sheet disposed between the inlet and outlet within the housing, and one or more filter assemblies as described herein.

[0185] The disclosure also relates to a method for cleaning a baghouse filter system, comprising providing a cleaning fluid (i.e., a second fluid flow) at a pressure of 0.20 to 760 kPa to one or more filter assemblies described herein mounted on a tubular sheet, thereby expanding a flow control component, which expands to exert mechanical pressure on the filter component in response to the cleaning pulse, causing it to dissipate, thereby inducing cleaning of the filter component. In some embodiments, a method for cleaning a baghouse filter system involves providing a reverse fluid flow at a pressure of approximately 0.20 kPa to approximately 1 kPa, or approximately 0.25 kPa to approximately 1 kPa, or approximately 0.3 kPa to approximately 1 kPa, or approximately 0.4 kPa to approximately 1 kPa, or approximately 0.4 kPa to approximately 0.9 kPa, or approximately 0.25 kPa to approximately 0.9 kPa, or approximately 0.3 kPa to approximately 0.9 kPa, or approximately 0.4 kPa to approximately 0.9 kPa, through one or more filter assemblies attached to a tube sheet (e.g., filter assemblies shown in Figures 3 to 5), thereby causing expansion of the flow control component. In a particular embodiment, a method for cleaning a baghouse filter system includes providing through one or more filter assemblies a second fluid flow that is pulsed at a pressure of about 1 to about 760 kPa, or about 10 to about 760 kPa, or about 50 to about 760 kPa, or about 70 to about 750 kPa, or about 70 to about 700 kPa, or about 100 to about 700 kPa, or about 125 to about 700 kPa, or about 150 to about 700 kPa, or about 170 to about 700 kPa, or about 170 to about 650 kPa, or can be pulsed at a pressure that falls within these ranges.

[0186] In some embodiments, a tube sheet (e.g., the tube sheet in Figure 1) may include one or more openings for mounting one or more filter assemblies. In some embodiments, a method for cleaning a baghouse filter system includes providing a reverse fluid flow through one or more filter assemblies (e.g., the filter assemblies shown in Figure 6).

[0187] In this embodiment, in response to a cleaning pulse, the expansion exerts mechanical pressure on the filter component, dissipating and thereby inducing cleaning of the filter component.

[0188] Figures 11A and 11B are schematic diagrams of a filter assembly 1100 in a normal flow for use in a pulse jet baghouse, according to embodiments disclosed herein. As shown, the filter assembly 1100 includes a filter component 1102a and a flow control component 1106a integrated into a support structure 1104a, forming a multilayer flow control unit 1120a. The filter component 1102a may include a filter medium and optionally a porous membrane (not shown) attached to the filter medium. The filter assembly 1100 can be used to filter particulate matter 1107a-1107c from a fluid flow 1108.

[0189] The filter assembly 1100 includes a flow control component 1106a integrated with the support structure 1104a, forming a multilayer flow control unit 1120a. The flow control component 1106a may be integrated with the support structure 1104a via bonding points 1114, 1115. The flow control component 1106a is in a more relaxed state relative to the support structure 1104a, thereby allowing the fluid flow to pass through the multilayer flow control unit 1120a and move within the layers. The flow control component 1106a and the support structure 1104a may include one or more flow control passages 1101a, 1103a that can become openings in the flow control unit 1120a. During normal operation, the flow control component 1106a may be in a relaxed state.

[0190] The flow control component 1106a can withstand structural failure caused by the stress of a propagating cleanup pulse (fluid flow in a second direction) that causes the flow control component to perform an expanding motion against the surface of the support structure 1104a. In some embodiments, the flow control component 1106a may include a sheet material. In certain embodiments, the sheet material may be non-porous. In some embodiments, the non-porous sheet material may be air-impermeable. In certain embodiments, the non-porous sheet material may be air-impermeable. In some embodiments, the sheet material may include a metal (e.g., aluminum, stainless steel, and copper) or a polymer non-porous film.

[0191] In some embodiments, the flow control component 1106a is a tubular component with one end closed and the other end open. Alternatively, the flow control component 1106a may have open ends (not shown). The multilayer flow control unit 1120a can be positioned within the filter component 1102a such that the flow control component 1106a is the innermost element. In this way, when operating in the first or normal direction, the multilayer flow control unit 1120a allows at least a portion of the first fluid flow 1108 to flow between the multilayer flow control unit 1120a and the filter component 1102a, and between each layer of the multilayer flow control unit, the support structure 1104a and the integrated flow control component 1106a. In another embodiment (not shown), the flow component 1106a is integrated with the support structure, thereby positioning the flow control component between the filter component 1102a and the support structure 1104a, and thus the support structure becomes the innermost structure of the filter assembly 1100.

[0192] During normal flow, as indicated by the arrows in Figures 11A and 11B, the fluid flows 1108a and 1108b flow in a first direction (e.g., the normal direction) through the filter components 1102a and 1102b, pass through the flow control passages 1101a and 1101b of the support structure 1104a (i.e., the first layer of the multilayer flow control units 1120a and 1120b), and then travel across the surface of the flow control component 1106a until they reach the flow control passages 1103a and 1103b within the flow control component (i.e., the second layer of the multilayer flow control unit 1120a).

[0193] As shown in Figures 11A and 11B, when particles or particulate matter are collected from the fluid flow by the filter components 1102a and 1102b, a dust cake, i.e., particles or particulate matter 1107a and 1107b, can accumulate on the filter components 1102a and 1102b. The purified fluid flow 1111 flows longitudinally along the internal space.

[0194] As indicated by arrow 1108c in Figure 11C, during a counterflow or pulse jet cleaning pulse, the second fluid flow 1108c flows in a second direction opposite to the normal direction, as shown in Figures 11A and 11B. During the cleaning pulse, at least one layer of the flow control unit 1120c expands outward, and the flow control component 1106c and, optionally, the support structure 1104c of the multilayer flow control unit 1120c are compressed together to seal the flow control passages 1101c and 1103c, preventing the fluid flow 1108c from passing through the flow control passages 1103c and 1101c. Therefore, the second fluid flow 1108c induces expansion of the multilayer flow control unit 1120c, causing a pressure pulse toward the filter component 1102c, which releases the collected particulate matter 1107c from the upstream surface 1112 of the filter component 1102c, thus cleaning the upstream surface 1112 of the filter component.

[0195] Figures 12A and 12B are schematic diagrams of a filter assembly 1200 in normal and reverse flow directions for use in a pulse jet baghouse, according to embodiments disclosed herein. As shown, the filter assembly 1200 may include a filter component 1202a and a flow control unit 1206a. The filter component 1202a may include a filter medium and optionally a porous membrane (not shown) attached to the filter medium. The filter assembly 1200 can be used to filter particulate matter 1207a-1207b from a fluid flow 1208.

[0196] The filter assembly 1200 further includes a flow control unit 1206a. The flow control unit 1206a can withstand structural failure caused by the stress of a propagating cleaning pulse that causes the flow control unit to perform an expanding motion against the surface of the filter component 1202a. In some embodiments, the flow control unit 1206a may include a sheet material. In certain embodiments, the sheet material may be non-porous. In some embodiments, the sheet material may be air-impermeable. In certain embodiments, a non-porous sheet material may be air-impermeable. In some embodiments, the sheet material may include a metal (e.g., aluminum, stainless steel, and copper) or a polymer non-porous film. The flow control unit may be flexible or rigid. In some embodiments, the flow control unit may include portions with varying thickness, such as a thick portion 1203a and a thin portion 1204a. The flow control unit may include flow control passages (not shown). The portions with varying thickness may form patterns such as dots, ribbons, grids, or cross-hatch patterns.

[0197] In some embodiments, the flow control unit 1206a is a tubular component with one end closed and the other end open (not shown). Alternatively, the flow control unit 1206a may be open at both ends. The flow control unit 1206a has directional flow resistance and also functions as a support structure for the filter component 1202a. The filter component 1202a can be positioned on top of the flow control unit 1206a so that the flow control unit 1206a becomes the innermost element of the filter assembly 1200. When operating in a first direction or normal direction, at least a portion of the first fluid flow 1208a flows between the flow control unit 1206a and the filter component 1202a. Also, when exposed to the first fluid flow, the flow control unit may be "pushed" or "bent" into the space within the filter assembly due to the pressure exerted by the first fluid flow 1208a. Space 1201 can be, for example, a distance d that can be varied according to the inflow pressure of the fluid flow 1208a and the flexibility of the flow control unit 1206a.

[0198] During normal flow, as indicated by the arrows in Figure 12A, the fluid flow 1208a flows through the filter component 1202a in a first direction (e.g., the normal direction) and then travels through the space or distance 1201 between the filter component 1202a and the flow control unit 1206a. As shown in Figure 12A, when particles or particulate matter from the fluid flow are collected by the filter component 1202a, a dust cake, i.e., particulate matter 1207a, can accumulate on the filter component 1202a. The space 1201 is formed by the distance d between the flow control unit 1206a and the filter component 1202a. In embodiments in which the flow control unit 1206a includes an air-impermeable and / or non-porous sheet-like material, the fluid flow 1208a passes through the filter component 1202a but not through the flow control unit 1206a. The purified fluid flow 1210 flows longitudinally along the space 1201.

[0199] As indicated by the arrows in Figure 12B, during a counterflow or fluid flow in a second direction, the second fluid flow 1208b flows in the opposite direction to the normal direction as shown in Figure 12A. In embodiments in which the flow control unit 1206b includes an air-impermeable and / or non-porous sheet-like material, the fluid flow 1208b does not pass through the flow control unit 1206b. Therefore, the second fluid flow 1208b induces expansion motion in the thinner portion 1204a of the flow control unit 1206b, causing a pressure pulse toward the filter component 1202b or vibrations inside the filter component 1202b, releasing the collected particulate matter 1207b from the upstream surface 1212 of the filter component 1202b, thus cleaning the upstream surface 1212 of the filter component 1202b.

[0200] Test method While specific methods and apparatus are described below, please understand that other methods or apparatus deemed appropriate by those skilled in the art may be used instead.

[0201] Small sample measurement Small sample measurements were performed on a 140 mm diameter sample using the apparatus described in ISO 11057. This apparatus is used for differential pressure measurement and can provide an indicator of the pressure generated during backpulse using the settings described in ISO 11057. For differential pressure measurement, the pressure was adjusted so that the face velocity was 2 m / min. Air permeability is reported in units of m / (min × Pa) as face velocity per differential pressure. The backpulse was set to 0.5 MPa and had a duration of 60 milliseconds. The pressure during backpulse was measured by an additional pressure transducer (model number: MMCG001BIV10K4A0T1A1, available from Omega Engineering, Norwalk, Connecticut) located immediately downstream of the filter assembly to evaluate the effectiveness of the backpulse. The measurement range of this pressure transducer was -7 kPa to 7 kPa.

[0202] Baghaus measurement Actual filter assembly measurements were performed in a laboratory-scale baghouse. This baghouse can accommodate nine bags, each 117 mm in diameter and 2.4 m long, and measures 85-340 m³. 3 The total airflow per hour could pass through the bag. Airflow was measured using a 160S-18PM "S" type Pitot tube (available from Dwyer Instruments, Michigan City, Indiana), and pressure drop was measured using upstream and downstream magnetic pressure transducers for pressure drop measurement (Dwyer Instruments, Michigan City, Indiana). Air permeability was reported in units of m / (min × Pa) as face velocity per differential pressure. The baghouse was equipped with a bag pulse system, and back pulses were applied simultaneously to three groups of three bags. The back pulses were introduced through a 12.7 mm diameter orifice nozzle located at the top opening of the bag. The pulse pressure and duration were controlled by a Goyen T series screw-type back pulse control system (Pentair Goyen Mecair, St. Paul, Minnesota). The nozzle position was adjusted based on the desired volume of back pulse flow. One bag had four additional pressure transducers (part number SSCDRRN005PDAA5, available from Honeywell International, Charlotte, North Carolina) mounted on the longitudinal interior of the bag, as shown in Figure 2A. The pressure sensors were located at 0.4, 1.0, 1.6, and 2.2 m from the top opening of the bag, respectively. These pressure sensors were used to measure the pressure distribution along the longitudinal direction of the filter assembly. In all experiments, only one filter assembly, rather than nine, was used in the baghouse to accurately measure the flow rate and pressure of a specific filter assembly. Data from these measurements were acquired using a Dataq Instruments DI-2108 data logger.

[0203] Flow resistance Flow resistance was measured as the reciprocal of air permeability. The value of flow resistance can be calculated using the formula "flow resistance = 1 / air permeability," and the unit is (min × Pa) / m when measuring air permeability, as provided in the small sample measurement test above.

[0204] Preparation of polyester filter bags

[0205] A rectangular section of 542 grams / square meter (gsm) (16 ounces / square yard) polyester felt (part number R4417 PE-16 / G-FPES, available from Southern Felt Company, Augusta, South Carolina) was cut to create a filter bag 2.5 m long and approximately 11.7 cm (4.6 inches) in diameter. The filter bag was constructed by sewing the rectangular pieces of material together to form a tube. An upper and lower cuff were sewn onto the tube. A snap band was added to the upper cuff to complete the filter bag.

[0206] support structure

[0207] The support structure was a steel wire filter bag cage manufactured by Royal Wire Products, Inc. of Charlotte, North Carolina, measuring 2,438 mm in length and approximately 114.3 mm (4.5 inches) in diameter and width. Each cage consisted of 16 wires spaced nearly evenly along its length and 12 wires spaced nearly evenly horizontally to form the cage. The top of each support structure was a roll flange slightly wider than its width, to which a venturi was attached. The venturi measured 13.3 cm x 15.2 cm, with a minimum throat diameter of 4.52 cm (5.25 x 6.00 inches, minimum throat diameter of 1.25 / 32 inches).

[0208] Preparation of flow control component #1

[0209] Weight 50g / m 2 (gsm), density 2.0g / cm 3A rectangular section of a (g / cc) perfluoroalkoxyalkane polymer (PFA) / ePTFE composite film was cut to create a tube 2.5 m long with a diameter of approximately 119 mm (±3 mm). The rectangular section was cut to a width of approximately 406 mm (±6 mm) and then folded in half lengthwise. The folded end was heat-sealed with a seam allowance of approximately 16 mm (±1 mm). Circular holes with a diameter of 9.5 mm were created by punching out approximately 230 holes / square meter (opening area approximately 1.64%) using a 9.5 mm die punch. The film was heat-pressed to create a tube with a seam running lengthwise. The flow control components were made slightly larger in size than the support structure and filter bag.

[0210] Preparation of flow control component #2

[0211] A rectangular section of a 50gsm weight, 2.0g / cc density PFA / ePTFE composite film was cut to create a tube 2.5m long with a diameter of approximately 119mm (±3mm). The rectangular section was cut to a width of approximately 406mm (±6mm) and then folded in half lengthwise. The folded end was heat-sealed with a seam allowance of approximately 16mm (±1mm). Using a 9.5mm diameter die punch, holes were punched at a frequency of approximately 216 holes / square meter (opening area approximately 1.54%) to create circular holes with a diameter of 9.5mm. The film was heat-sealed to produce a tube with a seam running lengthwise. The flow control components were designed to be slightly larger in size than the support structure and filter bag. [Examples]

[0212] example Example 1 (Comparative Example) As shown in Figures 2A and 2B, a polyester filter bag was mounted on a support structure to simulate a baghouse. To generate a low-pressure, high-volume pulse, the back pulse nozzle was positioned 15 cm above the filter bag opening. The back pulse consisted of a pressure of 172 kPa (25 psi) for 250 milliseconds. Data were measured in a laboratory-scale baghouse as described above, using four pressure gauges at distances of 0.4 m, 1.0 m, 1.6 m, and 2.2 m from the top opening of the bag. Figure 7 shows the pressures measured at four different locations within the filter assembly, which roughly correspond to the positions of the four pressure gauges along the longitudinal direction of the filter assembly. The pressures measured in this embodiment according to the prior art were relatively low at each location.

[0213] Example 2 To simulate the baghouse as shown in Figures 4A-D, flow control component #1 was mounted on the support structure, followed by the polyester filter bag. To generate a low-pressure, high-volume pulse, the back pulse nozzle was adjusted to a distance of 15 cm above the bag opening. The back pulse consisted of a pressure of 172 kPa (25 psi) for 250 milliseconds. As shown in Figure 8, the pressure measured in this embodiment was higher at each position compared to the prior art in Figure 7.

[0214] Example 3 The data for this example were measured using a laboratory-scale baghouse as described above. A polyester filter bag was attached to the support structure. The back pulse nozzle was positioned at the opening of the filter bag. In Test 1 (Figure 9A), a pulse of 207 kPa (30 psi) was used. In Test 2 (Figure 9B), a pulse of 414 kPa (60 psi) was used. In Test 3 (Figure 9C), a pulse of 620 kPa (90 psi) was used. The duration of each pulse was 100 milliseconds. In each test, only the third pressure transducer, located 1.6 m from the opening of the filter assembly, was activated.

[0215] Next, the flow control component #2 was attached to the support structure, followed by the polyester filter bag, and the experiment was repeated. This filter assembly with the flow control component attached was tested at 207, 414, and 620 kPa for durations of 100 milliseconds, as described above, and the results were plotted in Figures 9A, 9B, and 9C, respectively. In each of these tests, only the third pressure transducer, located 1.6 m from the opening of the filter assembly, was activated.

[0216] The results of each of the above tests are plotted in Figures 9A-C, showing the relationship between pressure (kPa) measured at the position of the third pressure transducer in the longitudinal direction of the filter assembly and time. The results in Figures 9A-C show that the pressure measured in the filter assembly with flow control components is significantly higher than that of a conventional filter assembly without flow control components.

[0217] Example 4 Example 4 measured the forward and reverse flow resistance and back pulse pressure for various filter assemblies using the small sample measurement method and flow resistance method described above. The results are shown in Table 1. The pressure sensor used was an Omega pressure sensor with a measurement limit of 7 kPa.

[0218] Sample 1 (for comparison) was a 542 gsm (16 ounces / square yard) polyester felt material (available from Southern Felt Company, Augusta, South Carolina). A circular sample with a diameter of 140 mm was cut from the bulk sample of polyester felt.

[0219] Sample 2 consisted of a 140 mm diameter circular polyester felt from Sample 1, with a 140 mm diameter circular flow control component made from a PFA / ePTFE composite film weighing 50 gsm and with a density of 2.0 g / cc placed downstream of the polyester felt. The flow control component had a single circular hole with an opening of 15.875 mm in diameter. The flow control component was positioned downstream of the filter component.

[0220] Sample 3 (comparison) was a GORE® filter bag 4427 (available from WL Gore & Associates, Elkton, Maryland), a highly durable filter assembly containing a porous membrane. A circular sample with a diameter of 140 mm was cut from a bulk sample of GORE® filter bag 4427.

[0221] Sample 4 was the same GORE® filter bag 4427 as described in Sample 3, but with a flow control component made from a PFA / ePTFE composite film having a weight of 50 gsm and a density of 2.0 g / cc, positioned downstream of the high-durability filter assembly. The flow control component had a single circular hole with a diameter of 15.875 mm.

[0222] Sample 5 (comparison) was a GORE® LOW DRAG filter bag 4470 (available from WL Gore & Associates, Elkton, Maryland). A circular sample with a diameter of 140 mm was cut from a bulk sample of GORE® LOW DRAG filter bag 4470.

[0223] Sample 6 was the same GORE® LOW DRAG filter bag 4470 low-resistance filter assembly, but the flow control component was made from a PFA / ePTFE composite film with a weight of 50 gsm and a density of 2.0 g / cc, and was positioned downstream of Gore's high-durability filter assembly. The flow control component had a single circular hole with a diameter of 15.875 mm.

[0224] For each sample, the flow resistance (min × Pa / m) in the forward (i.e., normal or forward) and reverse (i.e., second direction) directions was tested using a small sample measuring device. Table 1 shows the flow resistance in the forward and reverse directions. It can be seen that the samples with flow control components (2, 4, and 6) exhibit significantly higher flow resistance in the second direction compared to the comparison samples without flow control components (1, 3, and 5). This effect resulted in a significant increase in pressure during back pulses for all three assemblies. [Table 1]

[0225] Example 5 Filter assemblies 7-15 were fabricated. Filter assembly 11 was a comparative filter assembly that used the polyester filter bag and support structure described above and did not include flow control components. Filter assemblies 7-10 and 12-15 further included flow control components, which were placed on the support structure and subsequently on which the polyester filter bag was placed. Each flow control component was manufactured using the same method and the same film as flow control components #1 and #2 described above, but had circular openings of a diameter of 9.5 mm and at a frequency to form flow control components with different percentage opening areas, except for flow control component #12 which had no opening. The opening frequencies of the flow control components were as follows: Flow control component 7 - Opening frequency 122 pieces / m 2 . Flow control component 8 - Opening frequency 149 pieces / m 2 . Flow control component 9 - Opening frequency 176 pieces / m 2 . Flow control component 10 - Opening frequency 230 pieces / m 2 . Flow control component 13 - Opening frequency 108 pieces / m 2 . Flow control component 14 - Opening frequency 216 pieces / m 2 . Flow control component 15 - Opening frequency 324 pieces / m 2 . Flow control component 16 - Opening frequency 446 pieces / m 2 .

[0226] For filter assemblies 7-10 and Comparative Example 11, the flow resistance and face velocity were measured under normal operation (i.e., in the first direction) using the Baghaus measurement procedure described above. The face velocity and flow resistance data are summarized in Table 2. Since the flow resistance (min × Pa / m) was measured in the normal direction (first direction) while keeping the fan speed constant, the face velocity differed for each sample.

[0227] For each filter assembly 12-16 and Comparative Example 11, pressure data at the third sensor position (1.6m) was measured using pulse jet pressures of 207kPa, 414kPa, and 620kPa as the pulse jet pressure (i.e., the second direction). The pressure was measured at the third pressure sensor position (1.6m) along the length of the bag during back pulse generation. [Table 2] [Table 3]

[0228] As the two tables show, the flow control components added a slight additional flow resistance to the forward flow while significantly increasing the flow resistance in the reverse direction. This effect resulted in a significant increase in pressure during back pulses for all assemblies.

[0229] Example 6 Example 6 measured pulse pressure at various depths along the longitudinal axis of two filter assemblies. The comparative example without flow control components was a GORE® filter bag 4427, while the example was the same GORE® filter bag 4427 with added flow control components made from a PFA / ePTFE composite film with a weight of 50 gsm and a density of 2.0 g / cc. The film had an opening of 9.525 mm (3 / 8 inch), an opening area of ​​3.92%, and a frequency of 549 particles / m². 2These filter assemblies were tested using the small baghaus test procedure described above, but the back pulse was introduced through a 6.35 mm diameter orifice nozzle instead of a 12.7 mm orifice. An attempt was made to obtain similar pressures at a sensor located at 1.6 m using a back pulse pressure of 482 kPa (70 psi) in the example with flow control components and 682 kPa (90 psi) in the comparative example without flow control components. Figure 10 is a line graph showing the pressure (kPa) measured at various locations in the comparative filter assembly and a comparison with the filter assembly with flow control components according to the embodiments disclosed herein. The y-axis represents pressure, and the x-axis represents the length measured below the filter assembly. From this example, it can be seen that the example with flow control components generates a higher and more uniform pressure along the longitudinal axis of the filter assembly, even though a lower back pulse is used compared to the comparative example.

[0230] As shown by line 1002, the filter assembly according to the embodiments disclosed herein has a more uniform pressure distribution along the length of the filter assembly compared to the prior art shown by line 1004. Thus, the use of flow control components reduces the peak pressure at the inlet of the filter assembly and increases the pressure at the outlet of the filter assembly, enabling a more uniform pressure distribution along the length of the filter assembly and allowing for more efficient cleaning.

[0231] The invention of this application has been described in general terms and with respect to specific embodiments above. It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments without departing from the scope of this disclosure. Accordingly, the embodiments are intended to encompass modifications and variations of the invention, insofar as they remain within the scope of the appended claims and their equivalents.

Claims

1. A filter assembly for filtering granular material, Filter components, and, A flow control unit including at least a support structure and flow control components, Includes, The filter assembly may have a directional flow resistance, having a first flow resistance in a first direction when exposed to a first fluid flow, and a second flow resistance in a second direction when exposed to a second fluid flow.

2. The filter assembly according to claim 1, wherein the flow control unit includes a thin portion and a thick portion.

3. The filter assembly according to claim 1 or 2, wherein the first fluid flow is a gas flow containing particulate matter.

4. The filter assembly according to any one of claims 1 to 3, wherein the pressure of the second fluid flow is 0.20 to 760 kPa.

5. The filter assembly according to any one of claims 1 to 4, wherein the ratio of the first flow resistance to the second flow resistance is in the range of less than 0.01% to 99%.

6. The filter assembly according to any one of claims 2 to 5, wherein the thick portion covers at least 60% of the flow control unit.

7. The filter assembly according to any one of claims 1 to 6, wherein when the filter assembly is exposed to the second fluid flow in the second direction, the pressure within the filter assembly increases compared to the same second fluid flow without the flow control unit.

8. The filter assembly according to any one of claims 1 to 7, wherein the flow control unit is positioned downstream of the filter component with respect to the first direction of the first fluid flow.

9. The filter assembly according to any one of claims 1 to 8, wherein the flow control unit alternately transitions between a relaxed, unmasked state and an extended, masked state with respect to the filter component.

10. The filter assembly according to claim 9, wherein the flow control unit is in an extended masking state, and at least a portion of the flow control surface of the flow control unit is in contact with the surface of the filter component.

11. The filter assembly according to any one of claims 1 to 10, wherein the flow control unit includes a plurality of flow control passages, or the flow control unit includes regions of different thicknesses.

12. The filter assembly according to claim 11, wherein the flow control unit has an opening area of ​​0.01% to 50% of the total surface area of ​​the flow control unit.

13. The flow control passage has an average size of 0.0001 to 100,000 mm. ２ The filter assembly according to claim 11 or 12, comprising an opening.

14. The filter assembly according to any one of claims 1 to 13, wherein the flow control unit includes at least one flow control passage that can be in an open state or a closed state.

15. The filter assembly according to claim 14, wherein the at least one flow control passage includes a flap.

16. The filter assembly according to any one of claims 1 to 15, wherein the first fluid flow passing through the filter assembly in the first direction at a first velocity is subject to a first flow resistance, and the second fluid flow passing through the filter assembly in the second direction at a second velocity is subject to a second flow resistance, and the first flow resistance is different from the second flow resistance.

17. The filter assembly according to any one of claims 1 to 16, wherein the second flow resistance is greater than the first flow resistance.

18. The filter assembly according to any one of claims 1 to 17, wherein the first fluid flow passing through the filter assembly in the first direction is subjected to a first flow resistance of less than 4,000 (min × Pa) / m.

19. The filter assembly according to any one of claims 1 to 18, wherein the second fluid flow passing through the filter assembly in the second direction is subjected to a second flow resistance of more than 10 (min × Pa) / m.

20. The filter assembly according to any one of claims 1 to 19, wherein the filter assembly is cleanable.

21. The filter assembly according to any one of claims 1 to 20, wherein the flow control unit includes a sheet-like material, and the sheet-like material includes a porous sheet-like material, a non-porous sheet-like material, or a combination thereof.

22. The filter assembly according to claim 21, wherein the sheet-like material comprises silicone, silicone elastomer, fluorocarbon, fluorocarbon elastomer, microporous polymer densified or filled to remove at least some of the pores, polyacrylate, ethylene (meth)acrylic copolymer, polyimide, polyether ether ketone (PEEK), polyester, polybutylene terephthalate, polyethylene terephthalate, microporous polymer, wherein the polymer is polytetrafluoroethylene (PTFE), polypropylene (PP), polyethylene (PE), stretched PTFE, fluorinated ethylene propylene (FEP), perfluoroalkoxy polymer (PFA), ultra-high molecular weight polyethylene (UHMWPE), nitrocellulose, triacetylcellulose, polyamide, polycarbonate, polysulfone, polyvinyl chloride, polyvinylidene fluoride, acrylate copolymer, or a combination thereof.

23. The filter assembly according to claim 21 or 22, wherein the sheet-like material has a flow resistance greater than 16.5 (min × Pa) / m.

24. A method for cleaning a baghouse filter system, The method includes supplying a clean fluid flow at a pressure of 0.20 to 760 kPa through one or more filter assemblies according to any one of claims 1 to 23 attached to a tube sheet, thereby extending the flow control unit, The method involves applying mechanical pressure to a filter component in response to a cleaning pulse, and then dissipating it, thereby inducing cleaning of the filter component.

25. A flow control unit for use in a filter assembly, comprising one or more flow control passages, wherein the filter assembly, when exposed to a fluid flow, may have a directional flow resistance having a first flow resistance in a first direction and a second flow resistance in a second direction.

26. The flow control unit according to claim 25, wherein the flow control component has a percentage opening area of ​​0.01% to 50% of the total area of ​​the flow control unit.

27. The flow control unit according to claim 26, wherein the difference between the first flow resistance and the second flow resistance increases as the % opening area decreases.

28. The flow control passage has an average dimension of 0.0001 to 100,000 mm. ２ A flow control unit according to any one of claims 25 to 27, comprising an opening which is a flow control unit according to any one of claims 25 to 27.

29. The flow control unit according to claim 28, wherein the difference between the first flow resistance and the second flow resistance increases as the average size of the opening decreases.

30. The flow control unit according to claim 28 or 29, further comprising one or more flaps so that the one or more flow control passages can be in an open or closed state.

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