JP5805950B2 - Liquid filtration system - Google Patents

Description

  The present disclosure relates to a liquid filtration system and a filter medium, the filter medium comprising, for example, a polymeric fiber web having an adsorbing component therein.

  Many types of fluid filtration systems are commercially available, such as household water filtration. Traditionally, free carbon particle beds have been used to remove metals and / or organic materials from water. Composite blocks can be made from a combination of adsorbents such as adsorptive activated carbon and polymer binders such as polyethylene, which are simultaneously sintered under heat and pressure conditions and are useful in water filtration technology It is. The carbon block method provides functionality equivalent to liberating a carbon particle bed, for example, if the particles do not flake or occupy too much space. Using carbon block technology increases the pressure drop across the block and, as a result, the amount of adsorbent material such as activated carbon can be increased. Furthermore, exposing the carbon block to heat and pressure can limit the types of materials that can be used in the block. For example, the carbon block method generally cannot use a material that is easily pyrolyzed, such as an ion exchange resin.

  There remains a need to provide a compact water filtration system for home use. There is also a need to provide a system with a high loading of active material without increasing the pressure drop on the system. It is further desirable to minimize degradation of the filter media during processing. In addition, there is a continuing need to provide systems with improved service life.

  The present invention provides a filter medium, a method for producing the same, and a method for using the filter medium. The filter medium is suitable for liquid filtration and includes a melt-blown fiber web containing particles.

  In one aspect, a porous article comprising a self-supporting nonwoven polymeric fiber web and a plurality of adsorbent particles trapped in the web, the porous article having a first surface and a second surface; A filter element is provided comprising a liquid impervious housing that encloses a porous article, an inlet in fluid communication with a first surface, and an outlet in fluid communication with a second surface.

  Another aspect is a fluid filtration system comprising a fluid source and a filter element, the filter element having a self-supporting nonwoven polymer fiber web and a plurality of adsorbent particles trapped in the web. A porous article having a first surface and a second surface, a liquid impervious housing surrounding the porous article, an inlet in fluid communication with the first surface, and a second surface And an outlet in fluid communication with the system.

  In a further aspect, a block composite, a block composite having an activation medium in an amount ranging from 10 to 90% by weight of the block and a binder in an amount ranging from 10 to 90% by weight, and a carbon block composite. A filter element comprising a web surrounding and having a self-supporting nonwoven polypropylene fiber and a plurality of adsorbent particles trapped in the web in an amount ranging from 50 to 97% by weight of the web Is provided.

  In another aspect, there is provided a filter element having a plurality of disks attached to each other, wherein the disk has self-supporting nonwoven polypropylene fibers and a plurality of adsorbent particles trapped in the fibers. Is done.

  Another embodiment includes a fluid filtering method. The method includes contacting the filter element with a fluid, the filter element being a porous article having a web of self-supporting nonwoven polymeric fibers and a plurality of adsorbent particles trapped in the web. A porous article having a first surface and a second surface; a liquid impervious housing surrounding the porous article; an inlet in fluid communication with the first surface; and a fluid communication with the second surface. And an exit.

  In a further aspect, a method for forming a filter element comprising: flowing molten polymer from a plurality of orifices to form a filament; thinning the filament into fibers; and adsorbent particle flow to the filament or fiber. A method is provided comprising the steps of directing into a vortex, recovering the fibers and adsorbent particles as a nonwoven web to form a porous article, and placing the porous article in a liquid impervious housing. The

  Directly formed filtration articles and methods of manufacture and methods of use for fluid purification are also provided, the articles utilizing a particle-blended meltblown fiber web structure.

  In some embodiments, a plurality of porous layers wound to form a porous article having a web of self-supporting nonwoven polymeric fibers and a plurality of adsorbent particles trapped in the web A filter element comprising: a porous layer; a liquid impermeable housing surrounding the porous article; an inlet in fluid communication with the first surface; and an outlet in fluid communication with the second surface. Is provided.

  Another aspect is a first plurality of porous layers wound up to form a porous article, the first web of self-supporting nonwoven polypropylene fibers and the plurality captured in the first web. A porous layer having a plurality of carbon particles, a liquid impervious housing surrounding the porous article, an inlet in fluid communication with the first surface, and an outlet in fluid communication with the second surface A filter element is provided.

  A further aspect provides a method for filtering a fluid, the method comprising contacting a filter element with a fluid, the plurality of porous layers wound to form a porous article, and self-supporting A non-woven polymeric fiber web and a porous layer having a plurality of adsorbent particles trapped in the web, a liquid impermeable housing surrounding the porous article, and in fluid communication with the first surface And an outlet in fluid communication with the second surface.

  In another aspect, a method of forming a filter element comprising: flowing molten polymer from a plurality of orifices to form a filament; thinning the filament into fibers; and adsorbent particle flow to the filament or fiber. Conducting into the vortex, collecting the fibers and adsorbent particles on a spindle as a nonwoven web to form a porous article, and placing the porous article in a liquid impervious housing.

The schematic sectional drawing of a porous article. Sectional drawing of the porous article installed in the housing. Schematic of a housing. Sectional drawing of the porous article wound up helically installed in the housing. Sectional drawing of the lamination | stacking disk filter installed in the housing. 1 is a schematic diagram of representative components for producing a directly formed, particle-blended porous article. Schematic of a porous article. Sectional drawing of a porous article. Sectional drawing of a porous article.

  Prior to describing some exemplary embodiments of the present invention, it is to be understood that the present invention is not limited to the details of structure or process steps set forth in the following description. The invention is capable of other embodiments and of being practiced or carried out in various ways.

  Filtration articles for liquid purification are provided that utilize a particle-blown meltblown (or blow-molded microfiber-BMF) web in conjunction with a base to form a liquid treatment device. These particle-blended BMF webs are made by adding adsorbent material in the form of particles, particulates, and / or aggregates or blends thereof to a stream of air that feeds the fibers to the collector by thinning the polymer meltblown fibers. It is formed. The particles are trapped in the meltblown fibrous matrix and collected to form a web as the fibers come into contact with the particles in the mixed air stream. High loadings (eg, up to about 97% by weight) of particles can be utilized. Adsorbent materials include, but are not limited to, types of materials that alter the physical or chemical properties of a fluid, such as adsorbents and adsorbent materials and surface active materials. Examples of adsorbents include granular and powdered activated carbon, ion exchange resins, metal ion exchange zeolite adsorbents such as ATS from Engelhard, activated alumina such as Alzil from Selecto Scientific ( Alusil), antibacterial compounds such as, but not limited to, silver, zinc and halogen materials, acid gas adsorbents, arsenic reducing materials, iodide resins, and diatomaceous earth.

  Filtration media according to embodiments of the present invention include particle blended webs (non-calendered) and compressed / densified blended webs (calendered). These media have a low fluid flow resistance and show significant improvements in, for example, gravity flow and liquid filtration applications compared to commercial products. A further advantage is found in applications that require high flow rates. The open porosity of these compound webs hardly increases the flow resistance of the filter and housing. This low pressure drop on the media allows it to be used in high flow applications such as whole house filtration, as well as applications requiring gravity flow filtration. Over 90 wt% activated carbon loading has been demonstrated. A blending amount of at least 40%, 50%, 60%, 70% or 80% is also possible. Formulated webs have additional advantages over block technology when using heat sensitive particulates such as some ion exchange resins. The particles are not exposed to the high temperatures found during block molding or extrusion processes. Thereby, the concern about thermal instability related to the deterioration of the fine particles (ion exchange resin) is reduced. An open porous structure is also advantageous in high precipitation conditions. A very interstitial structure possesses a number of potential pathways for the fluid in contact with the particles. For home-wide filtration, it is desirable that large settled particles are trapped in the medium while smaller settled particles can pass through the medium. This provides a longer service life until the media is contaminated and the pressure drop is excessive.

  In one aspect, a porous article having a web of self-supporting nonwoven polymeric fibers and a plurality of adsorbent particles trapped within the web, the porous article having a first surface and a second surface; A filter element is provided that includes a liquid impervious housing that surrounds a quality article, an inlet in fluid communication with a first surface, and an outlet in fluid communication with a second surface.

  In a detailed embodiment, the adsorbent particles are activated carbon, diatomaceous earth, ion exchange resin, metal ion exchange adsorbent, activated alumina, antibacterial compound, acid gas adsorbent, arsenic reducing material, iodide resin, or combinations thereof. Have

In another embodiment, the web has a Gurley time of 2 (or 1 or 0.5 in other embodiments) or less . Other embodiments, filter, uniform face velocity of air per second 5.3cm under ambient conditions, 1 50 (or 75 or 30 in other embodiments) presented to show the pressure drop mm below water column To do. In certain embodiments, the average particle size of the particles is 250 (or 200, 150, 100, or 60) μm or less . Detailed embodiments present less than 10 minutes per gallon.

  In one embodiment, the web is wound to form an article. In another embodiment, the article is formed of a plurality of webs adjacent to each other. Detailed embodiments present that the first web comprises a first adsorbent and the second web comprises a second adsorbent. In another embodiment, the first web comprises particles of a first average size and the second web comprises particles of a second average size.

  In a further embodiment, the web substantially surrounds the core. The core can have a carbon block. Other embodiments include webs having a base web weight in the range of 10 to 1000 (or 20 to 300 or 25 to 100) grams per square meter. In another embodiment, the web has an adsorbent particle density in the range of 0.20 to 0.5 g / cc.

  In one or more embodiments, the polymeric fiber comprises polypropylene. In some embodiments, the polymeric fiber comprises a metallocene catalyzed polyolefin. In detailed embodiments, the polypropylene has a polymer melt flow index in the range of 30-1500 (or 75-750 or 200-500).

  Further embodiments provide that the web is compressed by calendering, heating, or pressing. Other embodiments include filter elements having an adsorption density gradient.

  Another aspect includes a fluid filtration system comprising a fluid source and a filter element, the filter element having a self-supporting web of nonwoven polymeric fibers and a plurality of adsorbent particles trapped in the web. A porous article having a first surface and a second surface; a liquid-impermeable housing surrounding the porous article; an inlet in fluid communication with the first surface; And an outlet in fluid communication with the surface.

  In one embodiment, the web is wound to form a porous article. In another embodiment, the porous article is formed of a plurality of webs that are adjacent to each other. In a further embodiment, the web substantially surrounds the carbon block.

  In a further aspect, a block composite, a block composite having an activation medium in an amount ranging from 10 to 90% by weight of the block and a binder in an amount ranging from 10 to 90% by weight, and a carbon block composite. A filter element comprising a web surrounding and having a self-supporting nonwoven polypropylene fiber and a plurality of adsorbent particles trapped in the web in an amount ranging from 50 to 97% by weight of the web Is provided.

  In another aspect, a filter element having a plurality of disks attached to each other, wherein the disks have self-supporting nonwoven polypropylene fibers and a plurality of adsorbent particles trapped in the fibers. Provided. A detailed embodiment is presented in which the first plurality of disks have first adsorbent particles of activated carbon and the second plurality of disks have second adsorbent particles of ion exchange resin.

  Another aspect includes a method for filtering a fluid. The method includes contacting the filter element with a fluid, the filter element being a porous article having a web of self-supporting nonwoven polymeric fibers and a plurality of adsorbent particles trapped in the web; A porous article having a first surface and a second surface, a liquid impervious housing surrounding the porous article, an inlet in fluid communication with the first surface, and in fluid communication with the second surface. And an outlet.

In a further aspect, a method for forming a filter element comprising: flowing molten polymer from a plurality of orifices to form a filament; thinning the filament into fibers; and adsorbent particle flow to the filament or fiber. A method is provided comprising the steps of directing into a vortex, recovering the fibers and adsorbent particles as a nonwoven web to form a porous article, and placing the porous article in a liquid impervious housing. . In one embodiment, the method further comprises compressing the nonwoven web by calendering, heating, or pressing to form a compressed web having a Gurley time of 2 seconds or less . In another aspect, the method further includes the step of applying a plurality of nonwoven webs adjacent to each other to form a porous article. Another embodiment presents that the method further comprises winding the nonwoven web and then placing the nonwoven web in the housing. Another embodiment includes controlling the rheology of the fibers.

  Also provided is a filtration article for liquid purification formed directly by collecting meltblown or blow molded microfiber (BMF) filaments with aggregates of particles, particulates or adsorbents on a rotating mandrel collector Is done. These particles are added to the BMF filament stream as it exits the die and are conveyed to a rotating mandrel collector. With additional adsorbents, additional undesirable chemicals and contaminants can be removed from the source water or liquid to be purified. By such a method, the filter diameter is formed in layers as the filter element is formed. In some embodiments, the filter element runs longitudinally in the lateral direction.

  Certain BMF filament fibers that do not have adsorbent material are intended to remove particulates and sediment from the water supply. Representative examples of this process are described in US Patent Application Publication Nos. 2004/0245171 and 2007/0175819 (Schimmel), the disclosure of which is incorporated herein by reference.

  When forming a BMF web by adsorbing material in the form of particles, particulates, and / or agglomerates or blends thereof by thinning the polymer meltblown fibers and adding these fibers to an air stream that is conveyed to a collector, the particles When the fibers come into contact with the particles in the mixed gas stream, they are trapped in the meltblown fibrous matrix and collected to form a web. High loadings (eg up to about 97% by weight) of particles can be utilized. Adsorbent materials include, but are not limited to, types of materials that change the physical or chemical properties of a fluid, such as adsorbents and adsorbent materials. Examples of adsorbents include granular and powdered activated carbon, ion exchange resins, metal ion exchange zeolite adsorbents such as ATS from Engelhard, activated alumina such as Alusil from Selecto Scientific , Antibacterial compounds such as, but not limited to, silver, zinc and halogen materials, acid gas adsorbents, arsenic reducing materials, and iodide resins.

  The directly formed filter element can have a gradient density obtained by adjusting meltblown filaments, compounded particulates, or both. In one or more embodiments, varying the meltblown filament airflow provides various effects. Filament size distribution fusion can be formed by mixing fiber airflows resulting from two or more separate dies operating at different target effective fiber diameters (EFDs). Similar effects can be obtained by using a hybrid blow molded article or by alternating fiber die chips as described in US patent application Ser. No. 11 / 461,136, see this description. As incorporated herein. Hybrid blow molding means can also be used to create regions of varying sizes of fibers or varying gradients of fiber sizes across the front face of the die. By doing so, the structure of the filter layer can be adjusted in accordance with, for example, use in a depth filter. Particles, particulates, aggregates, other regular, irregular or hollow shapes, or mixtures thereof are added to one or more of the filament streams and collected on a rotating mandrel or an advancing collection mandrel It is also possible to form filter elements.

  Another aspect is to have two or more dies operating in separate layers instead of having a mixed filament airflow. The dies can also be actuated side by side to create a distinct layered effect as the element traverses over the rotating mandrel. The use of various polymers or multicomponent fibers in one or more dies may cause further changes in performance.

  A graded or layered filter element can be formed by having a particle loader that uses a moving collector mandrel to add particulates only to the target area of the web. This can be accomplished by using a narrow particle loader with a wider die or by using a patterned feed roll in the particle loader. The feed roll uses a machined cavity to control the volumetric feed rate as the roll rotates against the doctor blade. By changing the volume of the cavity across (or around) the front surface of the feed roller, the local feed of fine particles can be controlled and, as a result, the local added weight of fine particles in the resulting web can be controlled. You can also.

  Another method is to use a split hopper in the particle loader. The fine particles are added only to the divided areas where the feeding is desired. This method also allows the use of two particle sizes by allowing the use of various particles within the divided areas, or controls the addition of treated adsorbents or those with special performance. You can also Multiple particle loaders can be used to vary the amount or type of particles added to the target region.

  By utilizing these measures, custom-made, directly formed filter elements for specific applications can be formed. For example, an inner layer of fine polypropylene fibers can be formed in the immediate vicinity of the mandrel core, helping to reduce shedding and peeling. Next to the inner layer, an intermediate layer of a particle-blended web can be provided for primary separation. In addition, an outer layer having a desired function can be formed on the intermediate layer, for example, so that the outer layer removes larger contaminants before reaching the primary separation layer. It is possible to have larger diameter fibers to have a larger pore size and / or to serve as an additional prefilter layer. Many other available arrangements can also be manufactured by those skilled in the art and are considered to be within the scope of the present invention.

  In some embodiments, a plurality of wound porous layers to form a porous article, comprising a web of self-supporting nonwoven polymeric fibers and a plurality of adsorbent particles trapped in the web A filter element comprising: a porous layer; a liquid impermeable housing surrounding the porous article; an inlet in fluid communication with the first surface; and an outlet in fluid communication with the second surface. Is provided. In one embodiment, the plurality of porous layers are fused together. In another embodiment, the plurality of porous layers are separate composite layers. In a detailed embodiment, the adsorbent particles are activated carbon, diatomaceous earth, ion exchange resin, metal ion exchange adsorbent, activated alumina, antibacterial compound, acid gas adsorbent, arsenic reducing material, iodide resin, or combinations thereof. Have

  In some embodiments, the filter element further has a core surrounded by the web. Other embodiments are presented where the web has an adsorbent particle density in the range of 0.20 to 0.5 g / cc.

  In one or more embodiments, the polymeric fiber comprises polypropylene. Some embodiments are presented where the polymeric fiber comprises a metallocene catalyzed polyolefin. In one embodiment, the metallocene catalyzed polyolefin comprises polypropylene. In other embodiments, the polypropylene has a polymer melt flow index in the range of 30-1500.

  In some embodiments, the first plurality of layers comprises polymeric fibers having a first effective fiber diameter and the second plurality of layers comprises polymeric fibers having a second effective fiber diameter. In another embodiment, the polymeric fiber has a mixture of effective fiber diameters.

  In yet another embodiment, the adsorbent particles are present at a first density in the first plurality of layers and at a second density in the second plurality of layers. Other embodiments include the first plurality of layers having a first adsorbent and the second plurality of layers having a second adsorbent. In a further embodiment, the first plurality of layers comprises particles having a first average size and the second plurality of layers comprises particles having a second average size.

  Detailed embodiments suggest that the filter element has an axial adsorbent density gradient. Another detailed embodiment presents that the filter element has a radial adsorption density gradient.

  In one embodiment, the filter element further comprises multiple layers of a second web of self-supporting nonwoven polymeric fibers that are substantially free of adsorbent particles.

  Another aspect is a first plurality of porous layers wound up to form a porous article, the first web of self-supporting nonwoven polypropylene fibers and the plurality captured in the first web. A porous layer having a plurality of carbon particles, a liquid impervious housing surrounding the porous article, an inlet in fluid communication with the first surface, and an outlet in fluid communication with the second surface A filter element is provided. In one embodiment, the porous article further comprises a second plurality of porous layers, wherein the porous layer is entrapped in the second web of self-supporting nonwoven polypropylene fibers and the second web. An ion exchange resin.

  A further aspect is a method for filtering a fluid comprising a plurality of porous layers wound up to form a porous article comprising the step of contacting a filter element with a fluid, and a self-supporting nonwoven fabric A polymeric fiber web and a porous layer having a plurality of adsorbent particles trapped in the web, a liquid impermeable housing surrounding the porous article, and an inlet in fluid communication with the first surface And an outlet in fluid communication with the second surface.

  In another aspect, there is a method for forming a filter element, the method comprising: pouring molten polymer from a plurality of orifices to form a filament; thinning the filament into fibers; and adsorbent particle flow to the filament. Or a step of directing into a fiber vortex, collecting the fibers and adsorbent particles on a spindle as a nonwoven web to form a porous article, and placing the porous article in a liquid impervious housing. .

  In one embodiment, the method includes a first plurality of layers comprising polymer fibers having a first effective fiber diameter and a second plurality of layers comprising polymer fibers having a second effective fiber diameter. Forming. In another embodiment, the method further comprises providing adsorbent particles in the first plurality of layers at a first density and in the second plurality of layers at a second density. Present. In another embodiment, the method further includes providing a first plurality of layers having a first adsorbent and a second plurality of layers having a second adsorbent. In a further embodiment, the method further comprises controlling the rheology of the fibers.

  References to “particle blended meltblown media” or “web” include filtration media consisting of a large amount of fibers (eg, microfibers) entangled in an open structure, with trapped particles between the fibers The particles are adsorbents for reducing or removing chemical contaminants, chlorine, and sediments and other substances from water.

  Reference to the term “trapped” refers to the particles being dispersed and physically held in the fibers of the web. In general, because of point and line contact along the fibers and particles, almost all of the surface area of the particles is available for interaction with the fluid.

  Reference to “adsorption density gradient” means that the amount of adsorbed material per square area through the filter does not have to be uniform, that more material is supplied in certain areas of the filter and more in other areas. Indicates that it can be changed to provide less material. For example, an axial adsorption density gradient is the amount of adsorbent per square area at one end of the filter along the central portion of the filter is different from the amount at the other end, Although it differs between, it represents that it does not change in the radial direction from the central portion. On the other hand, radial adsorption density gradients indicate that the core area has a different amount of adsorbent as it moves away from the central portion of the filter compared to the outer surface of the filter. The density variation need not be linear, but can be varied as required. For example, the density can be varied in a single step, multi-step, sinusoidal, etc.

  Reference to a “fluid treatment unit” or “fluid filtration system” includes a system having a filtration medium and a method of separating unpurified fluid, eg, untreated water, from treated fluid. This typically includes a filter housing for the filter element and an outlet for separating the treated fluid from the filter housing in a suitable manner.

  The terms particle and particulate are used substantially interchangeably. In general, particles are small pieces or discrete parts. The microparticles are related to or formed of a plurality of particles. The particles used in embodiments of the present invention can remain disjoint, or can be aggregated, physically engaged, electrostatically associated, or otherwise formed to form microparticles. You may combine with. In certain cases, agglomerates can be intentionally formed, such as those described in US Pat. No. 5,332,426 (Tang et al.).

  Reference to “calendering” includes the process of passing a product (eg, a web incorporating a polymeric adsorbent) through a roller to obtain a compressed material. The roller may be heated if desired.

The term “Gurley time” refers to the passage of a web sample having a circular cross-sectional area of about 645 mm ² (1 square inch) at a pressure of 1.2 kPa (124 mm (4.88 inches) H ₂ O) with 50 cc of air. Refers to the time required for Maintain a temperature of about 23-24 ° C. (74-76 ° F.) and 50% relative humidity for consistent measurements. “Gurley” time is W. W., Troy, New York. & L. E. It can be measured with a type of air permeability tester sold by W. & LE Gurley as the trade designation “Model 4110” air permeability tester, which is a Gurley-Teredyne ( Calibrated and operated using a Gurley-Teledyne) sensitometer (model number 4134/4135). Gurley time is inversely proportional to the void volume of the particle-blended web. Gurley time is also inversely proportional to the average pore size of the particle-blended web.

  The term “melt flow index” or “MFI” is also referred to variously as MFR or melt flow rate and is defined in test method ASTM 1238. Polypropylene polymer was measured using a "Method B" modified version of the ASTM 1238 test method.

  The term “meltblown process” refers to the process of producing fine fibers by extruding a thermoplastic polymer through a die consisting of one or more holes. As the fibers emerge from the die, they become thinner due to the airflow flowing approximately parallel to or tangent to the emerging fibers.

  The term “void volume” refers to a ratio calculated by measuring the weight and volume of a filter and then comparing the filter weight to the solid mass of the same volume of the same component material, which is the theoretical weight. .

  The term “pyrolysis” refers to the action of heat on a material. For example, certain adsorbent particles formed in a composite block or compounded web may be prone to physical instability during processes such as sintering or calendering. For polymers such as polypropylene, treating the polymer with heat alone or in combination with mechanical action can cause polymer chain scission, crosslinking, and / or chemical changes.

  The term “controlled degradation” refers to agents that are consumed in a degradation reaction in a controllable means, such as by input rate of specific heat and / or shear force, or by breaking the polymer chain and proportional to the amount of polymer. Incorporation includes a reduction in the molecular weight of the polymer and a narrowing of the molecular weight distribution.

  The term “porous” is the amount of voids in the material. The size, frequency, number, and / or interconnectivity of the pores and voids affect the porosity of the material.

  The term “controlled rheology” is defined as the use of radiation, peroxides or other free radical agents to adjust the rheological properties (eg viscosity and molecular weight distribution) of certain polyolefins, eg polypropylene, by degradation. can do.

  The term "densification" refers to compressing fibers deposited directly or indirectly on a filter take-up shaft or mandrel before or after deposition and whether intentionally or during or formed It refers to the process of manufacturing to form a less porous area widely or locally, whether as an artifact of some processes dealing with filters. Densification also includes web calendering methods.

Particle Blending Process A particle blending process is a process step added to a standard meltblown fiber formation process, as disclosed, for example, in commonly assigned US Patent Application Publication No. 2006/0096911. Is incorporated herein by reference. Blow-molded microfiber (BMF) is made by putting molten polymer into and out of a die, this flow extending across the width of the die within the die cavity, and the polymer is a series of orifices And extruded from the die as a filament. In one embodiment, the heated air stream passes through an air flow plate and air knife assembly adjacent to a series of polymer orifices that form a die outlet (chip). This heated air stream can adjust (stretch) the polymer filament to the desired fiber diameter by adjusting both temperature and speed. The BMF fibers are carried in the turbulent airflow toward the rotating surface, and when recovered on the surface, a web is formed.

  For example, the particle hopper is filled with desired particles, such as adsorbent particles consisting of activated carbon particles or ion exchange resin beads, where they gravimetrically fill the concave cavities in the feed roll. A rigid or semi-rigid doctor blade with a divided adjustment zone forms a controlled gap opposite the feed roll to regulate the flow from the hopper. The doctor blade is usually adjusted to contact the surface of the feed roll to limit particulate flow to the volume within the feed roll recess. As a result, the supply rate can be controlled by adjusting the speed of rotation of the feed roll. The brush roll operates behind the feed roll to remove residual particulates from the concave cavity. Particulates are placed in a chamber that can be pressurized by compressed air or other source of pressurized gas. The chamber is designed to create an air stream that carries the particles and mixes the particles with the meltblown fibers, which are thinned and conveyed by the airflow and exit the meltblown die.

  By adjusting the pressure of the forced air particulate flow, the velocity distribution of the particles is changed. Using very low particle velocities, the particles may be redirected by the die stream and not mixed with the fibers. At low particle velocities, particles may be trapped only on the top surface of the web. As the particle velocity increases, the particles begin to mix more thoroughly with the fibers in the meltblown stream and can form a uniform distribution in the recovered web. As the particle velocity continues to increase, some of the particles pass through the meltblown air stream and are trapped at the bottom of the collected web. At higher particle velocities, the particles may pass completely through the meltblown air stream without being captured by the recovered web.

  In another embodiment, using two generally vertical, diagonally arranged dies that generally eject opposing flow of filaments toward the collector, the particles are of two filament airflows. Sandwiched between them. Meanwhile, the adsorbent particles pass through the hopper and enter the first chute. The particles are gravity fed into the filament flow. The mixture of particles and fibers reaches the collector and forms a self-supporting nonwoven web incorporating the particles.

  In other embodiments, the particles are provided using a vibratory feeder, a discharge device, or other techniques known to those skilled in the art.

  In many applications, a substantially uniform particle distribution throughout the web is desirable. There may be cases where a non-uniform distribution may be advantageous. The gradient in the web depth may change the pore size distribution available for depth filtration. A web having a particle-blended surface can be formed into a filter where the fluid is exposed to the particles in the first half of the flow path and the remaining web provides a support structure and means to prevent the particles from falling off. The flow path can also be reversed so that the meltblown web can function as a prefilter to remove some contaminants before the fluid can reach the active surface of the particles.

  In a further embodiment, the collector is a take-up mandrel or rotary equipped with a filter cartridge extraction device designed to push and pull the forming filter cartridge substantially continuously from the rotary shaft. A cartridge take-up mechanism may be included that operates to form a separate filter on any of the cantilever shafts.

Polymer Rheology Control The controlled rheology of the polymers used in the meltblown fibers can adjust the web to have the desired properties. This is discussed in commonly assigned US Patent Application Publication Nos. 2004/0245171 and 2007/0175819 (Schimmel), all of which are incorporated herein by reference. For example, the strength of the web can be increased by adjusting the viscosity (eg, of polypropylene). A high degree of bonding between the fibers is desirable because the filter can be machined into a useful shape, such as a fluted cylinder, while at the same time maintaining good flow performance and high void volume.

  With respect to polypropylene, controlled degradation of polypropylene starting materials characterized by low MFI (high molecular weight) results in modified polypropylene having desirable properties for use in the manufacture of particle blended meltblown webs.

  In one embodiment, the web is made from a polypropylene polymer using controlled degradation to provide a material that exhibits a melt flow index of about 30 to about 1500 (or 75 to 50, or 200 to 500 in other embodiments). I will provide a.

  In another exemplary embodiment of the present disclosure, controlled degradation is performed by radiation with or without oxygen to produce a polypropylene polymer exhibiting a melt flow index of about 35 to about 350. Or thermally by the action of free radicals generated when one or more various reagents such as peroxides are heated. Thus, advantageous improvements in the rheology and physical properties of polypropylene are achieved through controlled degradation of the polymer.

  Referring to FIG. 1, a cross section of a porous article 10 is schematically shown. The article 10 has a thickness T, length and width of any desired dimensions. Article 10 is a nonwoven web having entangled polymeric fibers 12 and adsorbent particles 14 trapped in the web. Small coupled holes in the article 10 (not specified in FIG. 1) can allow water or other fluids to pass (eg, flow) through the thickness dimension of the article 10. The particles 14 denature the passing fluid, for example, by absorbing, adsorbing, or otherwise modifying contaminants and particulates present in such fluid.

  FIG. 2 is a cross-sectional view of the housing 20 that houses a filter element comprising a porous webd article 24 disposed on a porous core 22. The end cap 26 is attached to the web 24 by, for example, an adhesive (not shown). An inlet 28 to the housing 20 directs a fluid, e.g., water, toward the web 24, where the fluid contacts and is treated with adsorbent particles trapped in the web. The treated fluid enters a passage 27 defined by the core 22. The treated fluid then exits the housing through outlet 29.

  FIG. 3 shows a schematic view of a housing 30 having an inlet 38 and an outlet 39. This housing is suitable for the filter element that the invention embodies.

  FIG. 4 shows a cross-sectional view of a housing 40 having a wall 41 that houses a filter element comprising a spirally wound porous web-formed article 44 having a passage 47. The end cap 46 is attached to the web 44 by, for example, an adhesive (not shown). A fluid, such as water, enters the web 44, contacts the adsorbent particles trapped in the web, and is processed. The treated fluid enters a passage 47 defined by the core 22.

  FIG. 5 shows a cross-sectional view of a disk disposed in a housing 50 having an inlet 58 towards the laminated disk of webd material 54. The fluid contacts the stacked disc 54 and the processed fluid is collected in the reservoir 59.

  Referring to FIG. 6, a schematic diagram presents representative components of a system for producing a directly formed particle-blended porous article. A collector assembly 114 is shown comprising a rotating mandrel 122 having an inner end 124 mounted for rotation in a conventional manner on a support (not shown) via a bearing. The mandrel 122 also has an open distal end 116, an inner surface 120, and an outer peripheral surface 126. Meltblown die 112 feeds the particle blended nonwoven fibers 110, 110a, 110b, 110c, 110d, and 110e toward the collector assembly 114 to form a directly formed web structure.

  FIGS. 7 and 8 show a schematic view and a cross-sectional view, respectively, of a porous article 130 formed of a layer 138 of a nonwoven web 132 having particles 134. The fluid to be treated is placed in layer 138 and the treated fluid is flushed out of passage 136. In this embodiment, the particle density throughout the article is substantially uniform. FIG. 9 presents a cross-section of another porous article that is an example of a particle density gradient. In the cross section 142, the number of particles per unit area is larger than that of the area 144, and in turn, the number of particles per unit area of the area 144 is larger than that of the cross section 146.

  Unless otherwise indicated, all numerical values representing amounts and characteristics of components, such as molecular weight and reaction conditions used earlier in the specification and claims, are in any case modified with the word “about”. It should be understood that Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values that can be varied depending on the desired characteristics sought to be obtained by the present disclosure. is there. At the very least, and not intended to limit the application of the principle of equivalents to the scope of the claims, each numerical parameter should be at least a normal number, taking into account the reported significant figures. Should be interpreted by applying the rounding method.

  Although the numerical ranges and parameters shown throughout the present disclosure are approximate, the numerical values set forth in the specific examples are reported as accurately as possible. Any numerical value, however, inherently has certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

(Example 1)
A series of screening experiments were conducted to reveal the performance of the particle-blended meltblown web for water purification applications. Two basic resins were used: 350 MFI polypropylene sold under the trade name 3960 (Type 3960) (available from Total Petrochemicals), and trade name Vistamax 2125 80 MFI metallocene catalyzed polypropylene sold as (available from ExxonMobil). Several particle size grades of coconut shell activated carbon (available from PICA) sold under the trade name NC506 were evaluated. Woody carbon sold under the trade name Nuchar Aquaguard (available from Mead Westvaco) and coconut shell with titanium silicate coating sold under the trade name ATC N60260 Carbon (available from Calgon), coconut shell carbon sold under the trade name YPC 100MD (available from Kuraray), and cation sold under the trade name Dowex HCR-S Additional example webs with exchange resins (available from Dow Chemical) were also included in the specific test.

  A short yard roll of about 25.4 cm (10 inches) wide of the formulated web was collected under the following conditions. The polymer is from a die with 25.4 cm (10 inch) wide drill holes (DOD), for polypropylene based webs at 3.6 kg / hr (8 lb / hr) and for metallocene catalyzed polypropylene based webs. Extruded at 3.0 kg / hr (6.5 lb / hr). The distance from the die to the collector was 31.0 cm (12 inches). Samples of basic web (without fine particles) were collected at the target basis weight and C.I. N. Davis, CN, “The Separation of Airborne Dust and Particles”, Institution of Mechanical Engineers, London Proceedings 1B, 1952 The effective fiber diameter (EFD) was evaluated according to the method described in the year. Air temperature and speed were adjusted to achieve the target effective fiber diameter. The melting temperature for the various samples was recorded.

  After adjusting the basic web conditions to achieve the target basis weight and effective fiber diameter, the fine particles are added to the particle loader hopper and fed to provide the desired amount of adsorbent (carbon or ion exchange resin). The roll speed was adjusted. The air pressure toward the particle loader chamber was set between 3.4 and 13.8 kPa (each 0.5 to 2 psig). The settings were adjusted to aim for a uniform particle distribution throughout the web. The basis weight was expressed in grams per square meter (gsm). Base web refers to the weight of meltblown fiber web (unblended) per square meter. The compounded web refers to the weight per square meter of the meltblown fiber web compounded with media particles.

(Example 2)
Specific webs were selected from Example 1 to evaluate the effect of calendering on performance. A calendar with an adjustable gap between smooth chrome-plated steel rolls was used. The calender pressure in the sample was 414 kPa (60 psi) and the roll speed was 1.5 meters / minute (5 feet per minute). The roll diameter was 25.4 cm (10 inches) and had a roll front that was 56 cm (22 inches) wide. Each roll weighed approximately 272 grams (600 pounds) when filled with the oil used for temperature control by the Sterlco system. Nip pressure was applied using an ID 13 cm (5 inch) cylinder.

  The pressure drop over the particle-blended web was measured on a calendered web and its corresponding input web sample. The atmospheric pressure drop was measured using a constant front speed of 5.3 cm / sec relative to the air flow at ambient pressure of 1 atmosphere (101 kPa) at room temperature (about 22 ° C.).

  The web did not stick to the calendar roll under the evaluation conditions. The overall web width and possibly the entire length increased, especially at high temperatures. Web density was improved compared to non-calendered webs. The basis weight of the web includes accounting for dimensional changes after calendaring.

(Example 3)
Some samples of Examples 1 and 2 were attached to the filter as follows. For each sample, the web length required to obtain a filter having about 100 grams of media is obtained in one section of the web with approximate dimensions of 20 cm (8 inches) W × 30.5 cm (12 inches). Calculated from the weight. A core consisting of a rigid tube with approximate dimensions of OD 3.7 cm (1.45 inches) and a length of 35.3 cm (13.9 inches) was obtained. The tube had a 0.15 inch square opening across the tube. A length of web calculated to provide 100 grams of media was cut from a sample roll of 10 inches wide across a full width. In general, a web of about 3-4 feet (91 cm-122 cm) in length (depending on the loading), when cut to 20 cm (8 inches), resulted in a loading of about 100 grams. The web was glued to the OD of the tube. The web was wrapped over a suitable length around the tube. The outer edge of the web was bonded to the inner layer of the web. One end of the tube was cut at a position where good blending was visible. The other end was cut to obtain an approximately 20.3 cm (8 inch) long filter. The end of the filter was clamped with an end cap.

  The average OD of the filter was 6.9 cm (2.7 inches). The width of the OD was 6.1 cm to 7.3 cm (2.41 inches to 2.88 inches). The OD was 106 grams average media loading and ranged from 99 to 114 grams. The average density of the web-based filter using the non-calendered web was 0.20 g / cc activated medium.

  Calendering the carbon-blended web resulted in a finer filter structure. As a result, using a calendered web reduces the volume of material required for the filter and allows the use of small filter dimensions. The density of the filter using the calendered web ranged from 0.37 g / cc to 0.50 g / cc. The highest density of the calendered web (Sample 4) was 0.45 g / activated medium cc.

Example 4
Testing Some filters formed in accordance with Example 3 were evaluated according to performance tests including initial flash turbidity, absolute pressure drop, chlorine reduction, particulate reduction, gram life test, and Gurley value.

  For initial flash turbidity, the filter was connected to the water supply and the first water through the filter was collected. This method is based on a comparison of the light scattering intensity by a sample under defined conditions with the light scattering intensity by a standard control under the same conditions. The greater the amount of scattered light, the higher the turbidity level in water. The data was expressed in turbidity units by Nephelometry or NTU. A value of <0.5 NTU meets the NSF / ANSI drinking water standard. The first 1 liter was taken from the drainage stream. Turbidity was measured and recorded. The sample was then run at 2.8 liters / minute (0.75 gpm) and additional samples were taken at 3.8 liters (1 gallon), 19 liters (5 gallons), and 38 liters (10 gallons), Turbidity at each sample point was measured. The data includes Comparative Example 1 (a composite carbon block having a blend of 55% activated carbon medium and 45% polymer binder) and Comparative Example 2 (a carbon filter formed with granular activated carbon (GAC)).

  Referring to Table 3, in the blended web, the carbon fine particles were peeled off while flowing the initial 0 to 19 L (0 to 5 gallons). The web capture with larger carbon particles was better than that with smaller particles. The microparticles were believed to have decreased between 3.8-19 L (1-5 gallons). The amount peeled off (except for Examples 15 and 16) was less than the standard GAC axial flow filter, even in the case of 80 × 325 mesh size particles.

  Calendaring did not increase the initial flash turbidity. Furthermore, calendaring is thought to have reduced the initial turbidity, especially in the case of 80 × 325 carbon.

  For absolute pressure drop, a filter was connected to the water supply using a calibrated pressure gauge just before the system. The filter was opened to the atmosphere at the outlet of the system. The clean water was measured at 0.9, 1.9, 2.8, 3.8, 7.6, 11.4, 15.1 liters / minute (0 per minute through a rotometer capable of measuring flow rate. .25, 0.50, 0.75, 1.0, 2.0, 3.0, and 4.0 gallons). The pressure drop of the system with and without media was evaluated at various flow rates. A system having no medium is classified as Comparative Example 3.

  Referring to Table 4, in all cases, the pressure drop observed in the system with the blended web filter was 41.4 kPa (6 psi) of the system pressure drop in the unloaded system and in the reservoir with the filter. ). There was little contribution from the web filter to the overall pressure drop. During this test, no evidence of damage to the filter was observed.

  The non-calendered Sample 17 web media was removed from the filter that had been stored after the pressure drop test. The size of the particles retained after the high pressure test was measured using a manipulation electron microscope. This filter was found to retain particles having dimensions of 60-65 micrometers and above. Finer particle size retention is further enhanced by web calendering, the use of fine fiber diameters, or other techniques that reduce lattice voids or form bonds or bonds between particles and fibers. It should be.

  In the NSF / ANSI 42 chlorine reduction test, an inflow test concentration of 2.0 mg / L free chlorine (FAC) was used at a flow rate of 3.024 L / min (0.8 gallon / min) to determine the specific pH, turbidity, The filter was probed with water having a total organic carbon and water hardness. In order to achieve the demand for chlorine reduction, the filter needs to meet a minimum of 50% reduction or a maximum of 1.0 mg / L of free chlorine in the waste water. The comparison block, also referred to as “Comparative Example 4”, is 16.2 cm (6.395 inches) long and OD 3.8 cm as described in US Pat. No. 7,112,272 (Hughes et al.). (1.5 inches), a carbon block having an ID of 0.95 cm (0.375 inches) and having 60 wt% 80 × 325 pica (PICA) NC506 carbon and 40 wt% polyethylene binder. there were. The end cap was adhesively bonded directly to the open end of the carbon block. Table 5 shows the percentage reduction.

  Referring to Table 5, because filter samples were prepared using a fixed mass medium, the chlorine reduction test yielded similar results between calendered and non-calendered samples.

  In the NSF / ANSI 42 particulate reduction test, an in-line particle counter for class III testing was run with an inflow test concentration of about 1,000,000 particles at an initial flow rate of 9.5 L / min (about 2.5 gallons / min). Used to probe the filter. According to the NSF / ANSI 42 standard, the system reduces the number of particles within the test size range by at least 85% when tested according to the standard to receive a specific class rating. The evaluation of the system shall be consistent with the minimum particle size effectively removed as measured in the test. If there is a claim for a higher reduction rate, it must be demonstrated in a test. Comparative example 4 was tested in the same manner.

  Referring to Table 6, calendered samples 39 and 40 show improved particulate removal compared to the comparative carbon block.

  In the gram life test, the filter was exposed to a constant concentration AC roughness test dust aqueous solution of 1 gram test dust per liter (gallon). The end point was determined until the pressure drop across the media changed by 6.9 kPa (20 psi). The number of liters (gallons) that passed through the filter up to the defined end point was noted. When measured using this test dust, the longer the gram life, the longer the service life. Comparative example 4 was tested in the same manner.

  Referring to Table 7, the non-calendered samples 20 and 24 showed gram life results that were about 2.5 to 40 times higher than the comparison block.

  The Gurley test uses a Gurley Model 4110 air permeability tester as described in US Pat. No. 5,328,758 (Markell), and air 50 cc is 124 mm. With water column pressure, the time to pass through a web sample having an area of about 1 square inch (645 square mm) was measured at room temperature (about 23 ° C.). The samples presented in Table 4 show the pressure drop ranges shown in Table 2.

  Referring to Table 8, Gurley values were less than 1 second for various filters using both calendared and non-calendered webs.

(Example 5)
The webs of Sample 20 of Example 1 (web blended with palm carbon) and 26 (web blended with cation exchange) were attached to the filter as follows. These test samples were made by adhesively bonding a 100 mm diameter disc of compound web media along the inner edge of an OD 100 mm plastic ring with an ID 94 mm opening. Fine beads of hot melt adhesive were added around a 100 mm diameter disk of formulated web media. Another 100 mm disc was directly laminated (using adhesive) on top of the previous layer. This layering was repeated with 7 layers of carbon-blended web, then the target layer of the web blended with ion exchange, and then 3 more layers of carbon-blended web. Another plastic ring was adhesively bonded to the top surface of the media laminate. A laminated filter using the formulated web was assembled according to Table 9.

(Example 6)
Testing The filter of Example 5 was evaluated for TTHM reduction and gravity flow rate.

  In the NSF / ANSI 53 TTHM reduction test, the filter's total trihalomethane or TTHM reduction is assessed by first conditioning the filter by running 18.9 liters (5 gallons) of suitable NSF / ANSI general test water through the filter. did. Filters were tested under gravity flow conditions using chloroform inflow test water, 450 ± 90 ppb. The data described below was collected using injector conditions (gravity flow) as described in the ANSI 53 standard.

  Referring to Table 10, Samples 46 and 47 met NSF 53 TTHM standards at 227 liters (60 gallons) and 265 liters (70 gallons), respectively, based on an acceptable maximum effluent concentration of 80 ppb of chloroform. These results for TTHM removal show improved gravity filtration at carbon-based treated gallons / gram. The comparative example Brita OB01 / OB03 Classic style pitcher requires about 150 grams of active medium to meet a minimum value of 303 liters (80 gallons) in this test. This is in contrast to samples 46 and 47, which have 68-77 grams of active medium. In addition, Samples 46 and 47 had a flow rate that was about four times higher than the Brita product.

  For gravity flow rate, the time increment required for each liter (gallon) of solution to pass the filter of Example 5 was measured.

  For comparison purposes, the Brita OB01 / OB03 Classic has been reported to normally take 15 minutes to pass 1.9 liters (0.5 gallons). PUR Ultimate pitcher filters have been reported to require about 15 minutes to filter enough water to fill a 1.9-2.3 L (8-10 cup) carafe.

(Example 7)
Specific samples of Examples 1 and 2 were attached to the filter as follows. A carbon block measuring 20.3 cm × OD 2.9 cm (8 inches L × 1.125 inches) × ID 1.8 cm (0.7 inches) is described in US Pat. No. 7,112,272 (Hughes). Et al.). The composition of the block was 20% Aquaguard 80 × 325 activated carbon and 80% polyethylene binder. The particle-blended web material was wrapped around a carbon block until the resulting structure had an OD of about 7.6 cm (3 inches). For testing purposes, a 20 cm (8 inch) section was cut to a final length of 13 cm (5 inch). End caps were adhesively bonded to both ends of the composite structure.

  The comparative product is referred to as “Comparative Example 5” and has 70% active medium and 30% polymer binder. End caps were adhesively bonded directly to both ends of the carbon block.

(Example 8)
Testing Filters formed according to Example 7 were evaluated for chloramine reduction according to the NSF / ANSI 42 chloramine reduction test. The maximum effluent concentration according to this standard is 0.5 ppm. Comparative example 5 was also tested in the same manner.

  Referring to Table 12, samples 42 and 43 were calendered, allowing more than twice the amount of test liquid to pass through the filter compared to Comparative Example 5 while retaining chloramine below 0.5 ppm. I was able to.

Example 9
A directly formed cylindrical filter was formed from the meltblown web. A metallocene catalyzed polypropylene sold under the trade name Vistamax 2125 (available from ExxonMobil) is 2.9 kg from a die with a 2.5 cm (10 inch) wide drill hole (DOD). / Hr (6.5 lb / hr). The melting temperature was about 265 ° C. for all samples. The distance between the die and the collector was 30.5 cm (12 inches). A basic web sample (without fine particles) was collected and characterized to verify this condition. The basic web had a basis weight of 53 gsm. Thickness was 0.355 mm (0.014 inch). The pressure drop of 5.4 kPa (0.55 mm H ₂ O) was measured at ambient pressure of 1 atm at room temperature (about 22 ° C.) and a constant front speed of 5.3 cm / sec for the air stream. These conditions are C.I. N. Davis, CN, “The Separation of Airborne Dust and Particles”, Institution of Mechanical Engineers, London Proceedings 1B, 1952 According to the method described in the year, it corresponds to an effective fiber diameter (EFD) of 19 micrometers.

  After achieving the target effective fiber diameter, fine particles are added to the particle loader hopper to adjust the feed roll speed to provide about 90% by weight of palm activated carbon 60 × 140 sold under the trade name Pica NC506. did. The air pressure toward the particle loader hopper was set to about 17.2 kPa (2.5 psig) to provide a uniform particle distribution throughout the web.

  After changing the conditions, the particle-blended meltblown or blow-molded microfiber (BMF) filaments are approximately OD 3.7 cm (1.45 inches) long and 35.2 cm (13.9 inches) long. It was collected on a rigid tube with The tube had a 0.15 inch square opening throughout the tube. The tube was attached to the shaft and held in place with two rubber stoppers that slide along the shaft. The shaft was attached to the chuck of various speed hammer drills and the drill was operated at a maximum setting of 850 rpm. The spacer pair was extended 10 cm (4 inches) from the collector surface to provide a reproducible distance from the die to the mandrel. The mandrel shaft could resist slightly against these spacers (at either end of the tube) when collecting the sample. The tube and shaft were allowed to reach a sufficient rotational speed before being put into a particle blended meltblown or blow molded microfiber (BMF) filament stream. The collection time was changed to adjust the weight of the particle-containing filament collected on the tube. The core weight was 37 g for the full length sample. The weight of each core was measured before and after the recovery, and the fluctuations related to the contact between the mandrel and the airflow of the filament containing the particles were clarified.

(Example 10)
Testing Some filters formed according to Example 9 were evaluated according to performance tests including initial flash turbidity, pressure drop, and chlorine reduction.

  For initial flash turbidity, the test was performed as described in Example 4.

  The initial flash turbidity of Samples 49, 51, 52 and 54 was larger than that of Comparative Example 1 shown in Table 3, but smaller than Comparative Example 2 of Table 3. The initial flash turbidity improved as the cylinder OD increased. In either case, turbidity decreased to a level below 0.5 NTU.

  The test was performed as described in Example 4 for absolute pressure drop. The cylinder not blended is “Comparative Example 6”.

  The absolute pressure drop of these filters is low and such filters would be advantageous for household filtration applications.

  For the NSF / ANSI 42 chlorine reduction test, the test was performed as described in Example 4.

  Referring to Table 16, all samples removed acceptable chlorine concentrations for at least 8.7 kL (2300 gallons) in a test based on the 50% minimum reduction required by the standard. The number of liters (gallon) of water treated was directly related to the mass of active medium. Sample 57 showed the best performance, a reduction of> 90% of the inflow target even after 30.2 kL (8000 gallons). This is surprisingly due to the particle size of the carbon used and the low pressure drop of the structure.

  Throughout this specification, references to “one embodiment,” “a particular embodiment,” “one or more embodiments,” or “an embodiment” are specific to the embodiment described in connection with the embodiment. It represents that a feature, structure, material, or characteristic is included in at least one embodiment of the invention. Thus, the appearance of phrases such as “in one or more embodiments”, “in a particular embodiment”, “in one embodiment”, or “in an embodiment” in various places throughout this specification is It does not necessarily refer to the same embodiment of the present invention. Furthermore, the particular features, structures, materials, or characteristics may be combined into one or more embodiments in any suitable manner.

  Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the method and apparatus of the present invention without departing from the spirit or scope of the invention. Accordingly, the present invention is intended to embrace alterations and modifications that fall within the scope of the appended claims and their equivalents.

Claims (4)

Porous for treating a liquid having a web of self-supporting nonwoven polymeric meltblown fibers and a plurality of adsorbent particles trapped in the web in an amount ranging from 50 to 97% by weight of the web a quality article, comprising a porous article having a first surface and a second surface,
The plurality of adsorbent particles are those trapped in the meltblown fibrous matrix when the fibers contact the particles in the mixed air stream in meltblowing,
A liquid impervious housing surrounding the porous article;
An inlet in fluid communication with the first surface;
Further comprising an outlet in fluid communication with said second surface,
A filter element wherein the web has a Gurley time of less than 2 seconds. A fluid filtration system for processing liquid comprising a fluid source and a filter element, the filter element comprising:
A porous article having a self-supporting nonwoven polymeric meltblown fiber web and a plurality of adsorbent particles entrapped in the web in an amount ranging from 50 to 97% by weight of the web. comprising a porous article having a surface and a second surface,
The plurality of adsorbent particles are those trapped in the meltblown fibrous matrix when the fibers contact the particles in the mixed air stream in meltblowing,
The filter element is
A liquid impervious housing surrounding the porous article;
An inlet in fluid communication with the first surface;
Further comprising an outlet in fluid communication with said second surface,
The system, wherein the web has a Gurley time of less than 2 seconds. A carbon block composite having an activation medium in an amount ranging from 10 to 90% by weight of the block composite and an amount of binder in an amount ranging from 10 to 90% by weight;
A web surrounding the carbon block composite, comprising a self-supporting nonwoven polypropylene meltblown fiber, and a plurality of adsorbent particles trapped in the web in an amount ranging from 50 to 97% by weight of the web. And having a web having
The plurality of adsorbent particles are those trapped in the meltblown fibrous matrix when the fibers contact the particles in the mixed air stream in meltblowing,
A filter element for treating a liquid , wherein the web has a Gurley time of less than 2 seconds. A filter element for treating a liquid having a plurality of disks attached to each other, wherein the disks are self-supporting nonwoven polypropylene meltblown fibers and in an amount ranging from 50 to 97% by weight of the web. A plurality of adsorbent particles trapped in the fibers, wherein the plurality of adsorbent particles are trapped in the meltblown fibrous matrix when the fibers contact the particles in the mixed air stream in meltblowing. The filter element , wherein the Gurley time of the plurality of discs is less than 2 seconds.

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