HK1155712B - Controlled release of microbiocides - Google Patents

Abstract

A container for releasing a microbiocide component into a liquid composition susceptible to unwanted microbial growth (LCMG) includes a LCMG impermeable casing separate and apart from an internal combustion engine filter housing, and having a hollow interior and at least one opening. A microbiocide component, for example, at least one LCMG-soluble microbiocide, as the only active material located in the hollow interior. At least one liquid permeable element, for example, a membrane member, is provided at or near an opening in the casing and is effective to provide for release of microbiocide component into the LCMG. Methods of releasing microbiocide component into LCMGs are also provided.

Description

Controlled release of microbicides

Related application

This application claims priority to U.S. patent application No. 12/154,899 filed earlier than 27.5.2008, the entire disclosure of which is incorporated herein by this specific reference.

Technical Field

The present invention relates to devices and methods for providing microbiocides or biocides to liquid compositions susceptible to undesired microbial growth, such as, for example, liquid compositions of: cooling systems (such as, but not limited to, open loop cooling or coolant systems, such as cooling towers and the like), humidification systems, recirculating water injection systems, fire suppression canisters, fuel storage canisters, and the like.

Background

The liquids in various systems are plagued by undesirable microbial growth due to, for example, one or more of environmental conditions, liquid composition, exposure to atmospheric oxygen, and the like. In an attempt to mitigate this undesirable microbial growth, one or more of various chemical biocides or biocides are typically added to the system on a regular basis, such as each time the liquid level is adjusted and/or according to a set schedule. Herein, the terms microbicide and biocide are used interchangeably. Including, but not limited to, chlorine-containing biocides, bromine-containing biocides, and the like and combinations thereof. In general, the concentration of the microbiocide in the system can change due to evaporation, chemical neutralization, inactivation, degradation, and the like, and thus the concentration at any given time is unknown. Instead, a predetermined amount of biocide is combined, for example, with one or more additives in a predetermined ratio, and added to the system at normal maintenance intervals or whenever the liquid level reaches a point where level adjustment is required, or as appropriate.

Various methods of introducing additives into fluid systems have been widely suggested. United states patent No. 3,749,247 to rode (Rohde) illustrates a container for releasing oxidation inhibitors into hydrocarbon-based lubricating oils in working engines. The oxidation inhibitor is contained in a polyolefin container that allows the additive to permeate through the container wall into the oil. U.S. patent No. 5,591,330 to Lefebvre describes another approach which discloses a hydrocarbon oil filter wherein an oxidizing additive in a thermoplastic material is disposed in a housing between a particulate filter material and a felt pad. It is reported that the thermoplastic material dissolves in the presence of the high temperature oil, thereby releasing the additive. Further, U.S. patent No. 5,456,217 to french et al suggests the use of an additive release device in an engine hydrocarbon fuel line. The latter device comprises a partially permeable cylinder positioned in the filling neck of the fuel tank so that each time fuel is added, a portion of the additive content of the cylinder is released into the tank.

Water-based coolants present an environment different from those of hydrocarbon fluids. For example, most thermoplastic materials are not soluble in aqueous solutions. Moreover, relatively large amounts of additives need to be provided in typical aqueous coolants. The sudden supply of such large amounts of additives can cause "chunks" of material to settle out and circulate in the system, which can lead to pump seal damage and failure. Thus, U.S. patent No. 5,662,799 to hoggins et al suggests a complex diesel engine coolant filter that filters the coolant and releases a quantity of additive into the coolant via a diffuser tube or, alternatively, via a diffuser membrane. U.S. patent No. 5,435,346 to terigildgo et al and 4,782,891 to chiadel (Cheadle) et al suggest an alternative to this approach that takes advantage of the corrosive nature of the coolant to attack the separate components (e.g., rods) in the coolant filter and release corrosion resistant materials.

Glycol freezing point depressants (e.g., ethylene glycol and the like) are toxic to various microorganisms at the concentrations used in internal combustion engine coolants. In addition, the engine is operated at a temperature that kills most microbes, even in an all water coolant that will allow microbes to grow easily at room temperature. As a result, biocides or biocides are not typically used in the coolant of internal combustion engines.

However, other coolant compositions and other liquid compositions are susceptible to microbial growth in normal use applications.

It would be advantageous to provide an apparatus and method that is relatively inexpensive, quick to install, and achieves the following objectives: the microbiocide is released at a sustained rate into the other coolant and other liquid compositions susceptible to microbial growth so that the compositions function effectively without being excessively contaminated or otherwise significantly adversely affected by undesirable microbial growth.

Disclosure of Invention

New devices and methods have been found for providing release, preferably sustained release, of at least one microbiocide component into liquid compositions susceptible to undesirable microbial growth. The present apparatus and methods are effective to provide gradual, preferably sustained, and more preferably substantially controlled release of microbiocide component from the apparatus into a liquid composition, such as a substantially aqueous liquid; a liquid comprising water and at least one freezing point depressant (e.g., at least one glycol); a substantially non-aqueous liquid; and the like. Since the microbiocide component is only released through a limited portion of the device, for example, over a relatively long period of time, it has been found to be relatively convenient to substantially control the rate of release of the microbiocide component, which can be reduced relative to the rate of release of one or more additive components other than the microbiocide component.

Many of the components of the devices of the present invention, such as components other than the microbiocide component, are substantially insoluble in liquid compositions susceptible to undesirable microbial growth, even at the elevated temperatures of the composition in the working environment, and therefore these components remain intact and do not dissolve in the liquid composition and/or otherwise adversely affect the liquid composition or the system in which it is contained or employed. In addition, the insoluble components of the apparatus of the present invention may or may not be reused after release of the microbiocide component contained therein. The present device can be easily and directly manufactured, cost-effective, and can be easily and effectively used in a relatively wide range of systems/applications with little modification to effectively control microbial growth in the liquid composition used in the system/application in question.

In one broad aspect, the present invention relates to a microbiocide component container for releasing microbiocide component into a composition susceptible to unwanted microbial growth (e.g., a liquid composition). The container is typically designed to provide a gradual, preferably sustained, and more preferably substantially controlled release of at least one microbiocide component into a composition susceptible to undesirable microbial growth.

The container of the present invention comprises a housing separate and apart from the engine filter housing, for example, which is impermeable to the liquid composition susceptible to unwanted microbial growth (hereinafter LCMG) to be treated using the container. The housing defines a substantially hollow interior and at least one opening, such as at an outermost wall of the housing. In one embodiment, the housing includes only one opening. The microbiocide or biocide component is provided or located in the interior of the casing. In one embodiment, the microbiocide or biocide component is substantially the only active substance in the hollow interior of the casing, e.g., substantially the only substance effective to significantly affect or benefit the LCMG in contact with the casing. The microbiocide or biocide component may be provided in the form of a liquid, gel, paste or solid form. In a particularly useful embodiment of the invention, the microbiocide or biocide component is provided as a plurality of particles, or in particulate form (e.g., in the form of beads, tablets, pellets, granules, other particulate forms, and mixtures thereof).

The housing and other LCMG-impermeable components of the present device are preferably constructed of a material selected from the group consisting of suitable metals, LCMG-insoluble polymeric materials, combinations thereof and mixtures thereof. Useful housings may be made of a material selected from: metals, such as steel, aluminum, metal alloys, and the like; polymeric materials such as polyvinyl chloride, polyethylene, polypropylene, other polyolefins, nylon (nylon), polyethylene vinyl acetate (EVA), Polypropylene Vinyl Acetate (PVA), combinations thereof, mixtures thereof, and the like.

The container of the present invention further comprises at least one LCMG-permeable element or component provided at or near the at least one opening of the housing. The LCMG-permeable member, such as but not limited to, comprises a membrane effective to provide release of a portion of the microbiocide or biocide component in the casing into the LCMG, such as the LCMG in contact with the casing. The release occurs over a period of time such that a portion of the microbiocide component remains within the casing. Release may occur at a sustained rate or even a substantially constant rate, for example, at least after the initial release of the microbiocide component has occurred. The microbiocide component release obtained according to the present invention may involve diffusion of the microbiocide component into the LCMG, and is preferably a sustained microbiocide component release.

The LCMG-permeable element or component may comprise any suitable LCMG-permeable structure, and all such structures are included within the scope of the present invention. In one particularly useful embodiment, the LCMG permeable element or component comprises a membrane, such as a filter member or filter media (e.g., a porous or semi-permeable membrane).

The porous or semi-permeable membrane of the device of the present invention may be made of any suitable material that allows for the desired, preferably sustained, release of the microbiocide component into the LCMG, particularly when the casing is in contact with the LCMG. The membrane may be made of a LCMG insoluble material having, for example, irregularly sized channels or discretely sized holes therein. As used herein, a "porous" membrane generally refers to a membrane, such as a wire mesh or filter media (e.g., filter paper and the like), having pores in a substantially discrete size range. As used herein, a "semi-permeable" membrane refers to a continuous medium that does not have pores of a discrete size range, but rather preferably allows molecules to diffuse through narrow channels whose size is difficult to measure.

In one embodiment, the membrane (e.g., porous or semi-permeable membrane) comprises one or more metals and/or glasses and/or one or more polymeric materials and/or one or more papers and/or the like, combinations thereof, and mixtures thereof. Very useful membranes can be made from materials selected from: polyamides (e.g., nylon and the like), cellulosic components (e.g., cellulose acetate and other cellulosic polymers), glass, fiberglass, polyesters, polyurethanes, polyvinyl chloride, polyethylene vinyl acetate, polypropylene vinyl acetate, natural and synthetic rubbers, and the like, combinations thereof, and mixtures thereof.

In another broad aspect, the invention relates to a method of releasing a microbiocide or biocide component into a LCMG (e.g., a liquid coolant), preferably at a sustained, more preferably substantially controlled rate. Optionally, the LCMG may contain additives in addition to those released by the device of the present invention. The present methods comprise placing a container as set forth herein in contact with a LCMG. When the container is exposed to the LCMG, the LCMG passes (e.g., diffuses) through and/or at least wets the LCMG-permeable element and contacts and/or contacts a portion of the microbiocide component in the casing. Release, preferably sustained, substantially controlled release, of the microbiocide component into the LCMG is achieved, for example, by diffusion of the microbiocide component through the LCMG permeable member.

U.S. patent No. 7,001,531 relates to some related subject matter. The disclosure of this U.S. patent is incorporated herein by reference in its entirety.

Each and every feature described herein, and each and every combination of two or more of such features, is included within the scope of the present invention provided that the features included in such a combination are not mutually inconsistent.

Additional aspects and advantages of the present invention are set forth in the following description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals.

Drawings

FIG. 1 is a cross-sectional view of a cylindrical microbiocide container in accordance with the invention.

Fig. 2 is a schematic illustration showing the use of the vessel of fig. 1 in conjunction with an LCMG line.

FIG. 3 is a cross-sectional view of an additional embodiment of a microbiocide container according to the invention.

FIG. 4 is a cross-sectional view of another embodiment of a microbiocide container in accordance with the invention.

Fig. 5 is a view taken generally along line 5-5 of fig. 4.

FIG. 6 is a somewhat schematic view of yet another embodiment of a microbiocide container according to the invention.

FIG. 7 is a somewhat schematic view of a valved embodiment of a microbiocide container according to the invention.

FIG. 8 is a somewhat schematic view of another valved embodiment of a microbiocide container according to the invention.

Fig. 9 is a somewhat schematic view of an additional valved embodiment of a controlled release system for a portable additive composition according to the present invention.

Detailed Description

The present invention relates to containers for use in LCMG systems, including, but not limited to, such systems in or associated with heavy equipment (which includes both stationary and mobile equipment), as well as open circulating coolant or cooling systems, such as cooling towers and the like; a humidification system; a water injection system; a fire extinguishing tank; storage tanks, such as fuel storage tanks and other storage tanks; industrial recirculating closed cooling systems; a treatment fluid system, such as cutting oil and/or other processing oil; heated fluid systems, such as thermally heated fluid systems and the like; a swimming pool; hot springs; a fountain; a public bath system; a drinking water system; and the like.

The container is effective to gradually release (e.g., under sustained conditions) one or more microbiocide components (e.g., chemical microbiocide components) into a composition (e.g., a fluid composition, preferably a LCMG, susceptible to undesirable microbial growth) over an extended period of time.

Representative LCMG's include, but are not limited to, liquids, such as substantially aqueous liquids, with or without one or more additives effective to benefit the LCMG and/or the system in which the LCMG is used; a substantially non-aqueous liquid; and the like.

The size and shape of the containers of the present invention is not critical so long as the particular container used in a particular application is of a size and shape sufficient or appropriate to allow the container to effectively perform its function in that particular application, i.e., to provide the desired release of the microbiocide component into the LCMG. For example, but not limiting of, the size and shape of the container may range from a bowl-shaped container having a depth of about 3 inches or less to about 5 inches or more and a diameter of about 3 inches or less to about 6 inches or more to a cylindrical container having a length of about 2 feet or less to about 4 feet or more and a diameter of about 2 inches or less to about 6 inches or more. The volume of the hollow interior of the housing of the present invention can range from about 5 cubic inches or less or about 20 cubic inches to about 500 cubic inches or about 1500 cubic inches or more.

Generally, the container may be placed in contact with the LCMG to be treated. For example, but not limited to, the container may be placed in a pond or pool or lake of water to be treated. In a cooling system, the container may be placed in an open trough of flowing water. In other cases, the container may be placed in a larger cylinder through which water is pumped by, for example, but not limited to, a circulation pump on a cooling tower. In still other cases, the container may be placed in a sump or liquid sump of a cooling tower or humidification system. The containers can be of various sizes and shapes to facilitate placement in the system to allow contact with the LCMG to be treated and release of the microbiocide component into the LCMG.

The LCMG typically initially (i.e., prior to treatment in accordance with the present invention) includes one or more additives to provide one or more benefits to the LCMG and/or the system in which the LCMG is employed. LCMG treatable in accordance with the invention includes an aqueous composition (i.e., a composition that includes a significant amount of water, e.g., at least about 50% or about 70% or about 80% by weight); and non-aqueous compositions (i.e., compositions comprising less than about 50%, or about 30%, or about 10% by weight water). The LCMG may be substantially anhydrous, or anhydrous, e.g., containing about 5% or less by weight water. Optionally, the LCMG may contain one or more additives in addition to those released by the device of the present invention. These additives include, but are not limited to, those additives conventionally used in LCMGs of the type in question.

Lcmcgs may be susceptible to unwanted growth of one or more types and/or species of microorganisms. For example, but not limited to, included in the microorganism are bacteria, fungi, viruses, spores, and the like and combinations thereof. The microorganisms (microorganisms or microbes) may be present in an environment which houses and/or in which the LCMG is employed. Additionally, or alternatively, the LCMG may render the microbiocide component in the inventive device effective to substantially prevent any significant growth of one or more particular microorganisms (such as, but not limited to, one or more microorganisms that may be introduced into the LCMG either unintentionally or via human or natural intervention). In other words, the microbiocide component in the inventive device may be used to substantially prevent the growth of any one of the microorganisms in the LCMG, to control the growth of one or more microorganisms in the LCMG, and/or to reduce the population of one or more microorganisms in the LCMG (e.g., a LCMG contaminated with an excess population or quantity of one or more microorganisms). Thus, the present device may be used to substantially prevent, control and/or reduce microbial growth in LCMGs.

Unless expressly stated to the contrary, each of the words "comprising," "including," and the phrases such as "for example" and the abbreviation "e.g," used herein to refer to one or more things or activities, means that the reference is not limited to the specific reference of the one or more things or activities.

The present container includes a shell having or defining a substantially hollow interior, such as a LCMG-insoluble and LCMG-impermeable shell. The housing has at least one opening. The housing may have any suitable shape and size, which is generally selected to be compatible with the particular application involved. For example, the housing may have a generally cylindrical shape, a generally bowl shape, or any of a number of other shapes. The housing may have one or more curved and/or planar walls, or it may all be curved or planar.

The at least one opening in the housing may be provided at any position or at any location of the housing. For example, the opening or openings may be located at the top and/or bottom and/or ends and/or side or sides of the housing as desired. The location of the opening is typically selected based at least in part on the particular application involved and/or the ease and/or cost of manufacturing the microbiocide component containers of the present invention and such factors and may have at least some effect on the performance of the containers.

To more clearly illustrate and explain the present invention, emphasis is placed herein on cylindrical housings and bowl-shaped housings. However, the present invention is not limited thereto and is applicable to housings of other shapes. Containers comprising such other shaped housings are included within the scope of the invention.

In one embodiment, the housing may be, for example, cylindrical having a first end and a second end. The housing is provided with at least one opening, for example at one or both of the first and second ends of the housing and/or in the side wall. The housing may be substantially bowl-shaped. For example, the bowl-shaped housing defines a hollow interior, a top, a bottom, and one or more sidewalls. The openings may be located in the top, bottom, and/or one or more sidewalls.

For example, but not limited to, a microbiocide component comprising at least one LCMG-soluble microbiocide is provided in the hollow interior of the casing. At least one LCMG-permeable element is provided at or near the at least one opening of the housing. For example, an LCMG-permeable element is advantageously provided at or near each opening of the housing. This LCMG-permeable element or elements are effective to provide for the release of a portion of the microbiological components into the LCMG in contact with the casing, e.g., in a sustained manner over time, while maintaining the balance of the microbiocide component within the casing.

The housing of the container may be made of any suitable construction material or materials. The casing itself has substantially no deleterious effect on the microbiocide component or the LCMG or on the performance of the container of the present invention. The housing is preferably constructed of a material selected from the group consisting of: metals, such as steel, aluminum, metal alloys, and the like; polymeric materials, combinations thereof, and mixtures thereof. In one particularly useful embodiment, the housing is selected from the group consisting of metal, polyvinyl chloride (PVC), polyethylene (high and/or low density), polypropylene (PP), nylon, polyethylene vinyl acetate (EVA), Polypropylene Vinyl Acetate (PVA), polyester, acetal, Polyphenylene Sulfide (PPs), and the like, combinations thereof, and mixtures thereof.

In one embodiment, the at least one LCMG-permeable element or component of the present container preferably comprises at least one LCMG-permeable membrane (e.g., porous or semi-permeable membrane) that facilitates or permits contact of the LCMG with the microbiocide component provided within the casing. If desired, the membrane may optionally be accompanied by at least one membrane retaining means or two or more retaining means (e.g. an open mesh screen, woven cloth and the like) to effectively retain the membrane in a substantially fixed position relative to (e.g. within) the housing.

The LCMG-permeable membrane of the invention is advantageously composed of a suitable LCMG-insoluble material, preferably selected from the group consisting of polymeric materials, glasses, metals, combinations thereof and mixtures thereof. For example, suitable materials include, but are not limited to, glass, polyamides (e.g., nylon and the like), cellulosic polymers (e.g., cellulose acetate and the like), polyesters, polyethylene vinyl acetate (EVA), Polypropylene Vinyl Acetate (PVA), polyvinyl chloride (PVC), polyurethanes, stainless steel mesh, sintered metals (e.g., sintered metal discs and the like), metal film filters (e.g., silver film filters and the like), and the like, as well as combinations and mixtures thereof. In one embodiment, the film comprises a material selected from: cellulose; cellulose salts such as, but not limited to, cellulose acetate, cellulose sulfate, cellulose phosphate, cellulose nitrate and the like and mixtures thereof; cellulose esters; a polyester; polyamides, glass and the like and combinations thereof.

The membrane can alternatively be a material through which the microbiocide component can pass, for example, by diffusion (but not necessarily via pores), such as silicone rubber, polyethylene, polyvinyl acetate, natural and synthetic rubbers, and other polymers and waxes, and combinations and mixtures thereof. The membrane is commonly referred to as a semi-permeable membrane. In one embodiment, "semi-permeable membrane" refers to a continuous thin film of LCMG permeable material (such as, but not limited to, polymeric material) that allows diffusion of molecules through microscopic channels. The pore size of such semi-permeable membranes is not easily measured and is typically less than about 0.2 microns.

The LCMG-permeable membrane of the invention preferably comprises a porous membrane, advantageously a microporous membrane, such as those having an average pore size in the range of about 0.2 microns or about 1 micron or about 2 microns to about 30 microns or about 40 microns to about 300 microns or more. As referred to herein, a "film" may be a single layer or may comprise multiple layers. The thickness of the film is preferably in the range of about 0.1mm or less to about 0.5mm or about 1mm or about 5mm or about 10mm or more, although other thicknesses may be effectively employed. Examples of membrane materials include wire mesh; polymers, such as polyamides, e.g., nylon and the like, other polymers disclosed elsewhere herein, and the like, meshes; a filter media; combinations thereof and mixtures thereof and the like. Useful membrane materials include materials used as filter media. Examples of such materials include filter media sold under the trade name STRATTOPORE by the Freund Division of Cummins Engine (Fleetguard Division of Cummins Engine) and filter media commercially available from Voteman (Whatman) and Millipore (Millipore).

The presence and/or size of pores in the LCMG-permeable membrane used in accordance with the invention is not a controlling factor in determining the release rate of the microbiocide component into the LCMG. Other factors that may be important or at least have an effect in determining the release rate of the microbiocide component into the LCMG include, but are not limited to, the membrane construction material, the physical dimensions (e.g., thickness, volume, and the like) of the membrane, the presence and/or strength (density) of charge (if any) on the membrane material, the microbiocide component used, the degree of hydrophilicity/hydrophobicity of the membrane material, the form of the microbiocide component, and the like.

To illustrate, each of two membranes having the same physical dimensions are used in accordance with the invention in different identical containers containing the same amount of the same bromine-containing microbiocide. Each container was used to release the microbiocide from the container into the water in the same manner and the rate of release of the microbiocide was measured. A membrane is formed from cellulose (a charged material) having an average pore size of 20-25 microns. The other membrane was formed from an uncharged glass having an average pore size of only 5 microns. However, it was found that glass membranes with smaller pores had a higher or increased release rate of the microbiocide component compared to charged cellulose membranes.

Thus, many factors may be considered in selecting or selecting the membrane material to be used in the present invention to achieve the desired release rate of the microbiocide component. In one embodiment, the material of construction of the membrane and the pore size of the membrane may be selected to control the release rate of the microbiocide component into the LCMG.

The rate of flux release of the microbiocide component through the membrane is defined as milligrams or mg./hr./mm of the microbiocide component released per hour through a 1 square millimeter membrane². Since release flux rates vary over a wide range and are at least sometimes relatively slow, tests using benzyltriazole have been developed to quantify certain release flux rates that may be useful according to the present invention. This test was performed as follows.

A tank with twenty (20) gallons (gallon) of tap water along with a circulating heater is provided for mixing and temperature control. The temperature was set to 80 ° F. Once this temperature is reached, a vessel containing benzyltriazole (such as that shown in figure 1) is placed in a tank in contact with water. Water samples were collected at regular intervals over a 100 hour period and the benzyltriazole content was measured. From these measurements, the benzyltriazole release flux rate of the membrane was determined. For the sake of illustration, assume a 100 hour transit through 351mm²The membrane area (the area exposed by the opening in the outermost wall of the vessel) released 300mg of benzyltriazole. The benzyltriazole release flux rate isOr 0.0085mg./hr./mm²。

The benzyltriazole release flux rate useful for the membranes of the present invention may be in the range of about 0.001mg./hr./mm²Or less than about 0.3mg./hr./mm²Or within the above range, for example, about 0.002mg./hr./mm²To about 0.2mg./hr./mm²Within the range of (1).

It should be noted that benzyltriazole release flux can be used as a measure of whether a membrane according to the invention is useful. However, benzyltriazole release flux rates are not the only basis on which the usefulness of a particular membrane can be measured, determined or estimated. For example, prototype testing may be employed, and other testing using the actual membrane and/or actual microbiocide to be used may be employed. A benzyltriazole release flux rate that is too high or too low does not necessarily render the tested membrane unusable in the present invention. Some microbicides may not be adequately released through a membrane having a rate of benzyltriazole release flux deemed acceptable, or may be adequately released through a membrane having a rate of benzyltriazole release flux deemed unacceptable. In any event, within the limits mentioned above, the benzyltriazole release flux rate has been found to be a useful tool in determining the suitability of the membrane material in the present invention.

In the event that the selected material is not sufficiently rigid or stable under the conditions of use of the apparatus of the present invention (e.g., without limitation, repeated hot-cold cycles of the cooling system), a more heat resistant material (e.g., one made of ceramic, glass, and the like, combinations thereof, and mixtures thereof) may be employed as the membrane construction material.

The membrane may be secured to the casing so as to cover the opening in the casing, for example so that the microbiocide component does not pass outside the casing without passing through the membrane. The membrane is advantageously positioned in and/or directly adjacent to said opening in the housing. The membrane may be adhered to the housing using a suitable and compatible adhesive, press fit to the housing, interference fit to the housing, or otherwise securely affixed to the housing.

In one embodiment, the housing defines only one opening in the outermost wall of the housing and the membrane is provided in or directly adjacent to the only one opening.

As mentioned above, in one embodiment, the LCMG permeable element further comprises at least one retaining member. For example, the membrane may be held across the opening of the housing by one or more wires or mesh screens (e.g., stainless steel mesh screens). The membrane may be sandwiched between at least two retaining members. The retention member is preferably configured, for example, to have a mesh size to facilitate or allow passage of the microbiocide component, for example, by diffusion, from the casing to be passed through into the LCMG in contact with the container.

For example, the retainer member preferably has a mesh size in the range of about 10 to about 300 microns or about 500 microns or more. Particularly preferred retaining members are metal (e.g., stainless steel mesh) and/or woven cloth.

The microbiocide component provided in the container of the present invention is effective in controlling (e.g., substantially preventing, substantially maintaining or reducing) unwanted microbial growth in the LCMG when released therein. The microbiocide component may be provided in the casing in the form of a liquid, gel, paste, or solid particles (e.g., beads, tablets, granules or granules, and the like, and mixtures thereof).

The microbiocide component of the present invention may advantageously further comprise a coating material that at least partially surrounds or encapsulates or coats the microbiocide component, as discussed elsewhere herein. The coating material can be provided to at least assist in controlling, or to control the release of the microbiocide component, as desired. The coating material may be LCMG-soluble or LCMG-insoluble. The coating on the microbiocide component should, for example, allow or permit release of the microbiocide component from the casing into at least some of the LCMG.

The microbiocide component of the present invention may be included in or may be located in a binder material and/or a matrix material (e.g., a LCMG-insoluble biocide material and/or a matrix material, such as a LCMG-insoluble polymer material). Examples of the binder material and matrix material include, but are not limited to, cellulose, LCMG insoluble cellulose derivatives and the like and mixtures thereof. Other binders and matrix materials that are used with the microbiocide (e.g., without limitation, conventionally and/or commercially used with microbiocides), advantageously LCMG insoluble binders and matrix materials, can be used in or with the microbiocide component of this invention. The binder material and/or matrix material (if any) should, for example, allow or permit release of the microbiocide component from the casing into the LCMG. Advantageously, the binder material and/or matrix material is effective to at least assist in controlling, or controlling, the release of the microbiocide component into the LCMG. In one embodiment, the microbiocide component may be present in the casing and no binder material and/or matrix material is employed.

In one embodiment, as discussed herein, the LCMG-permeable element comprises a polymer-containing membrane (e.g., a polymer-coated membrane) to achieve enhanced microbiocide component release control. In this latter aspect, the membrane (i.e., of the LCMG permeable element) is suitably coated, impregnated, or otherwise associated with the polymeric material, for example, by spraying, dipping, and the like, via the polymeric material. Suitable polymeric materials include, but are not limited to, LCMG-insoluble materials that do not have a significant deleterious effect on the LCMG being treated, the microbiocide component, or on the performance of the container of the present invention. Examples of such coating materials include those listed in U.S. patent No. 6,010,639 to Mitchell (Mitchell) et al, the disclosure of which is incorporated herein by reference in its entirety. In one embodiment, the polymeric material is a polyethylene vinyl acetate copolymer. Additionally, or alternatively, the present retaining members of the LCMG-permeable element may be coated, impregnated, or otherwise associated with a material, such as a coolant-insoluble polymeric material, such as those disclosed in U.S. Pat. No. 6,010,639 to Michell (Mitchell), et al, to at least assist in controlling or to control the release of the microbiocide component from the casing, as desired.

Other examples of useful coatings are disclosed in U.S. patent No. 6,878,309 to Blakemore (Blakemore) et al, the disclosure of each of the identified patents being incorporated herein by reference in their entirety.

The container of the present invention is preferably filled with the microbiocide component through an opening in the casing or otherwise.

Containers of the present invention (e.g., casings of containers) can include one or more LCMG-impermeable cap members or LCMG-impermeable plugs that can be detached or detached from the casing or the remainder of the casing to, for example, facilitate filling of the interior space of the casing with a microbiocide component or an additive composition comprising a microbiocide component.

In useful embodiments, the container of the present invention (e.g., the housing of the container) may further comprise another opening to the hollow interior; and the container may further comprise a structure operatively coupled to the other opening. This structure may be operable to allow at least one or both of the following: (a) allowing air to exit the hollow interior via the other opening; and (b) passing the LCMG (e.g., aqueous liquid or water) into the hollow interior via another opening.

The container is particularly useful in applications where a liquid composition (e.g., LCMG, aqueous liquid, liquid water, and the like) is to be passed into the hollow interior of the container to facilitate release of the microbiocide component into the LCMG outside of and/or in contact with the casing. In other words, another opening and structure set forth herein facilitates and/or facilitates the efficient movement of air out of the hollow interior while allowing liquid (e.g., as set forth herein) to enter the hollow interior.

In one embodiment, the structure includes a removable plug configured to be placed in another opening to close the other opening. For example, the container may include a removable plug in another opening or port in the casing that is removable to allow introduction of a liquid (e.g., LCMG, aqueous liquid, liquid water, and the like) into the hollow interior via the other opening to wet the microbiocide component. Some microbicides are hydrophobic or otherwise not wettable by LCMG in contact with the container. In such cases, it may be advantageous to introduce water, or other LCMG, directly into the hollow interior to wet the microbiocide component and promote initial release of the microbiocide component into the LCMG. In other words, in the absence of water or such direct introduction of the LCMG, the microbiocide component in the hollow interior will not be wetted by the LCMG in contact with the casing for an extended period of time, and therefore will not be released into the LCMG over such extended period of time. In practice, pre-wetting the microbiocide component allows reasonably timely and controlled release of the microbiocide component to the LCMG in contact with the casing. Once the water has been introduced directly into the hollow interior, the plug is repositioned in the other opening to close the other opening.

The structure may include a valve operable between a first position to allow air to exit the hollow interior via the other opening and a second position to substantially prevent air from exiting the hollow interior via the other opening. As air exits the hollow interior, a liquid (e.g., as mentioned elsewhere herein) may be introduced into the hollow interior, for example, via another opening, to replace the air that has been removed. The valve may be located substantially within the hollow interior or substantially outside of the hollow interior.

Any suitable valve may be used as the structure of the present invention. The valve should be operable and effective under the conditions of use of the container and should be made of compatible materials, i.e., materials that do not cause or produce or have any undue or significant deleterious effect on the container during storage or use or on the LCMG being processed. Examples of useful valves include, but are not limited to, ball float valves, spring loaded valves, and the like. The valve may be adjusted so that the internal pressure within the hollow interior created by, for example, liquid entering the hollow interior may be controlled by adjusting the valve to achieve a desired internal pressure before the valve opens so that air exits the hollow interior via another opening in the housing.

In one embodiment, the structure may include an air permeable membrane member positioned over another opening. The air permeable membrane member is configured and positioned to allow air to exit the hollow interior via the other opening and to substantially prevent liquid (e.g., LCMG, etc.) from exiting the hollow interior via the other opening.

The air permeable membrane member may be positioned in or cover the other opening, for example, using an adhesive and/or other attachment means and/or by an interference fit in the other opening.

The air permeable membrane member may be made of a material and/or have properties such that the air permeable membrane member allows air to escape the hollow interior without allowing liquid water, LCMG and the like to escape. For example, the air-permeable membrane member may be made of a non-wetting material and/or have a size and porosity sufficiently lower than the liquid-permeable membranes set forth elsewhere herein so as to not actually facilitate release of the microbiocide component through the air-permeable membrane member. For example, the liquid permeable membrane may have a porosity of about 20 microns to about 30 microns and about 40cm²To about 60cm²And the air permeable membrane member may have a porosity of about 1 micron to about 10 microns and about 1cm²To about 10cm²The area of (a).

The air permeable membrane member is made of any suitable material, for example, a material that is sufficiently durable to be effective for use with the container of the present invention and is compatible with the rest of the container and the LCMG being treated.

In another embodiment, where the container includes an opening for primarily releasing microbiocide component to the LCMG and another opening, the same membrane material may be used to cover the opening and the other opening. For example, but not limited to, in which 51cm is required²To obtain the desired release of microbiocide component from the hollow interior, the area of the opening will be greater than the other opening (e.g., about 6 cm)²) Large, e.g., at least about 5 times (e.g., about 45 cm)²). In this embodiment, it would be advantageous to place the larger opening below or downstream of the smaller other opening. In this embodiment it is advantageous that the membrane material employed to cover both the opening and the further opening is suitable as the material of the liquid-permeable membrane member.

In one embodiment of the invention wherein the casing is substantially cylindrical and the opening is located at the end of the casing, one or both ends of the casing may include a cap member, wherein at least one of the cap members is removable to allow the casing or barrel to be filled or refilled with the microbiocide component. The other open end of the housing may optionally include a cap member permanently sealed thereto, for example during manufacture (e.g., during injection molding of the container). Whether the cap or plug is attached by screwing or tightening it onto the housing, the stud bolt threads may be applied to the respective piece during or after molding with a suitable die or in a mold. Alternatively, the cap member may be applied to the housing by press fitting. In this case, suitable tolerances for snap-fitting between the housing and the end piece can be provided, for example, for a plastic injection mold used to make the respective piece. The end piece may also be integrally formed with the housing, for example, during injection molding.

The cap or end piece used to close at least one end of the casing containing the microbiocide component is typically provided with at least one opening to allow the release of the microbiocide component therethrough and to provide fluid communication between the LCMC located outside the container and the microbiocide component disposed inside the casing. When the end piece is integrally formed with the housing, the opening may be provided therein during or after the formation of the housing, for example, by injection molding.

It will be appreciated by those skilled in the art that the release of microbiocide component into the LCMG is provided by the container of the present invention, and that the rate of release may be substantially controlled by several considerations. The following factors, as well as others, may also have an effect on the performance and effectiveness of the containers of the present invention. For example, a desired rate of release of the microbiocide component may be achieved by appropriate selection of the following factors: the number and type of film layers; film composition; membrane pore size (if any); the presence, type, and amount (if any) of polymer associated with (e.g., coated on) the membrane; and the presence, type and amount (if any) of a coating on the microbiocide component. The release rate may also be affected by the number and size of the openings in the housing and the like. Other factors that should be considered include, among others, the type and form of the microbiocide component, the solubility of the microbiocide component in the LCMG to be treated, the temperature of the LCMG to be treated, and the speed of the LCMG through the LCMG line or system to be treated, and the like.

The invention further encompasses methods of releasing the microbiocide component, preferably at a controlled rate, into the LCMG. The method comprises placing a container or cylinder containing the microbiocide component as described herein in contact with the LCMG. The container or cartridge configuration described herein preferably allows for the release, preferably controlled release, of the microbiocide component from the interior of the casing into the LCMG. It is contemplated that in some configurations, the LCMG is allowed to flow around and around the casing containing the microbiocide component. However, even in these configurations, release of the microbiocide component is preferably sustained and/or controlled, for example, by diffusion (e.g., passive diffusion) rather than by forced flow of the LCMG through the casing.

The microbiocide component used in the containers or cartridges of the present invention is preferably provided as a liquid, gel, paste, or as particles (e.g., beads, tablets, pellets, granules, coated forms of these and the like and mixtures thereof). The particles are of a physical size large enough to prevent passage through the LCMG-permeable component of the invention, as set forth elsewhere herein.

The microbiocide component for use in the present invention is, for example, effective in playing some beneficial role in the LCMG and/or the system in which the LCMG is used or employed. In one embodiment, the microbiocide component is effective in controlling unwanted microbial growth in the LCMG and/or the system in which the LCMG is used or employed. As mentioned elsewhere herein, the microbiocide component may be effective to prevent undesired microbial growth in the LCMG and/or system, reduce undesired microbial growth (i.e., reduce the population of undesired microorganisms) in the LCMG and/or system, and/or maintain the population of undesired microorganisms in the LCMG and/or system at an acceptable or tolerable level. In short, the microbiocide component has an effect on the population of undesirable microorganisms in the same LCMG and/or system as compared to the population of undesirable microorganisms in the LCMG and/or system in which the microbiocide component is not present.

In useful embodiments, the microbiocide component is substantially the only active material in the hollow interior of the casing. That is, the microbiocide component is essentially the only substance in the interior of the casing that, when released from the casing, is effective to have a significant or measurable effect on the LCMG in contact with the casing and/or on the system in which the LCMG is housed. For example, one or more materials (e.g., corrosion inhibitors, oxidation inhibitors, foam inhibitors, cavitation pads, pitting/corrosion inhibitors, deposition and scale inhibitors, dispersants, organic acids, and/or anti-gelling agents) are advantageously not present in the hollow interior with the microbiocide component. In the context of this paragraph, delayed and/or sustained and/or controlled release coatings, fillers and matrices associated with the microbiocide component in the hollow interior of the casing are not considered active materials.

The microbiocide component is typically present in an amount of at least about 30 percent by weight of the material present in the hollow interior of the casing. Advantageously, the microbiocide component is present as a major amount, i.e., at least about 50 percent by weight of the material in the hollow interior of the casing. The microbiocide component may constitute at least about 70% by weight or at least about 90% by weight or more of the material present in the hollow interior of the casing.

Any suitable (e.g., without limitation, effective) microbicide or biocide component may be employed in accordance with the present invention. In one useful embodiment, the microbiocide component is or is included in a U.S. Environmental Protection Agency (EPA) registered microbiocide component.

Advantageously, the microbiocide component is partially compatible with the container or cartridge and its components in which it is disposed, compatible with the LCMG to be treated, and compatible with the system in which the LCMG is used or employed. For example, and without limitation, the microbiocide component may be selected so as not to be unduly degraded or damaged by, and not to cause undue degradation or damage to, the container, the LCMG to be treated, and the system in which the LCMG is used or employed. In addition, the microbiocide component may be selected to be effective in controlling the LCMG to be treated and/or the microorganisms (e.g., specific microorganisms) present in the system in which the LCMG is used or employed. The microorganisms may include, but are not limited to, bacteria, viruses, fungi, spores, and the like, many of which are known to contaminate, foul, or otherwise adversely affect the appearance and/or performance of the LCMG and/or the system in which it is used or employed if left uncontrolled to propagate or grow.

Examples of useful microbiocide components include, but are not limited to, halogen-containing microbiocides, such as microbiocides including compounded halogens, e.g., chlorine-containing microbiocides, bromine-containing microbiocides, and the like and mixtures thereof; halogen-releasing biocides, for example the following materials: for example, including halogen-releasable materials, materials that release microbiocidally effective amounts of halogen (e.g., chlorine, bromine, and the like) into the LCMG, and the like and mixtures thereof; thiocarbamate microbiocides and the like and mixtures thereof; thiazoline microbiocides and the like and mixtures thereof; thiocyano microbiocides and the like and mixtures thereof; sulfate microbiocides and the like and mixtures thereof; quaternary ammonium microbicides and the like and mixtures thereof; metal-containing biocides and the like and mixtures thereof; and the like and mixtures thereof.

Specific examples of useful microbiocide components include, but are not limited to: 5-chloro-2-methyl-4-isothiazolin-3-one; 2-methyl-4-isothiazolin-3-one; methylene-bis (thiocyanate); sodium dimethyldithiocarbamate; disodium ethylene-bis-dithiocarbamate; trichloro-s-triazinetrione (trichloroisocyanurate); potassium peroxymonosulfate; potassium hydrogen sulfate; n-alkyl dimethyl benzyl ammonium chloride; bis (tri-n-butyltin) oxide; poly (oxyethylene (dimethylimino)) ethylene (dimethylimino-ethylene dichloride); 2, 2-dibromo-3-nitrilopropionamide (DBNPA); 1-bromo-3-chloro-5, 5-dimethylhydantoin; 1, 3-dichloro-5, 5-dimethylhydantoin; 1, 3-dichloro-5-ethyl-5-methylhydantoin; and the like and mixtures thereof.

The amount of microbiocide component released into the LCMG by the container or cartridge of the present invention depends on a number of factors such as, but not limited to, the particular LCMG to be treated, the particular microorganism to be controlled, the extent of microbial growth to be controlled, the configuration and/or size and/or operating conditions of the particular system in which the LCMG is used or employed, and the like. The effective concentration of the microbiocide component in the LCMG can vary over a wide range, depending on a number of factors including, for example, one or more of the same factors set forth in this paragraph. The concentration may be in the range of about 0.0001% or less to about 0.5% or more by weight of the LCMG. Useful microbiocide component concentrations may range from about 0.0001% or about 0.001% to about 0.01% or about 0.1% or about 0.5% by weight of the LCMG.

The container or cartridge of the present invention is advantageously used separately and apart from the engine (e.g., internal combustion engine), filter housing, since the engine is typically operated at high temperatures sufficient to control microbial growth without the need for a microbiocide component.

The container or cylinder of the present invention may be placed in the LCMG filter upstream or downstream of the filter media, or it may be placed in a system where the LCMG is used or employed and separated (spaced) from the LCMG filter, or it may be provided in a substantially fixed location in the LCMG line upstream or downstream of the LCMG filter. The release of microbiocide component into the LCMG is at least partially governed by one or more of the following: membrane pore size, membrane thickness, membrane composition, surface area of the membrane, viscosity of the liquid microbiocide component, surface tension and membrane wetting ability of the microbiocide component and/or the LCMG, LCMG system operating conditions (e.g., temperature, pressure, and the like), and the like.

The invention will now be illustrated with reference to certain examples, which are intended to illustrate, but not to limit the invention.

Example 1

Referring now to fig. 1, container 10 comprises a PVC housing 12 (which includes a solid, open end, a generally cylindrical housing body 13) and an end cap 14 which is fitted onto the housing body using a pair of pegs 16 which extend inwardly from end 17 of cap 14, fitting into an annular groove 18 in the outer side wall 19 of the housing body. The housing body 13 has an open end 20 and an opposite closed end 21. The housing 12 defines a hollow interior 22.

Particles 24 containing only a microbiocide component are provided within hollow interior 22. No other additives are included in the hollow interior 22. The microbiocide component, such as 2, 2-dibromo-3-nitrilopropionamide (DBNPA), is effective to control (e.g., substantially prevent) microbial growth in coolant compositions in contact with container 10. The coolant composition (e.g., an aqueous liquid coolant used in a cooling tower) is susceptible to undesirable microbial growth in use, and is therefore a LCMG.

The porous membrane 27 is adhered to the inner wall 28 of the end cap 14 and covers an opening 30 provided in the end cap. The membrane 27 is made of nitrocellulose and has an average pore size in the range of about 20 to about 25 microns. The benzyltriazole release flux rate, as defined herein, is about 0.049mg/hr/min². The adhesive used to adhere the film 27 to the end cap 14, for example, is insoluble in the LCMG to which the film is to be exposed and still effective as an adhesive. The binder should also be compatible with the LCMG and the microbiocide present in the container 10, e.g., without significant or excessive deleterious effects on the LCMG or on the microbiocide or on other components of the container 10. Examples of useful adhesives include, but are not limited to, epoxy resins; a phenol-based resin; an acrylic resin; a cyanoacrylate resin; a silicone adhesive; a polyurethane adhesive; hot melt adhesives such as poly (ethylene vinyl acetate (EVA)), polyamide resins, polyester resins, and the like; contact adhesives, e.g. those based on rubber, styrene resins and the likeSuch as this; and the like and combinations thereof.

The container 10 may be placed in a bag or other protective sleeve or package for shipping/storage.

The diameter of opening 30 in end cap 14 may vary over a relatively wide range, such as in a range of about 1mm or less to about 50mm or 80mm or more. In one embodiment, the diameter of the opening is in the range of about 2mm to about 20mm or about 40mm, for example about 8mm to about 10 mm. Of course, the opening need not be circular, but may be other shapes, such as square, rectangular, polygonal, and the like. Advantageously, the area of an opening having a configuration other than circular may be substantially equivalent to the area of a circular opening having the diameter mentioned herein; in particular, at about 0.7mm²Or less to about 2000mm²Or 5000mm²Or above; or about 3.2mm²To about 350mm²Or about 1250mm²Or about 50mm²To about 80mm²Within the range of (1). An opening 30 in the end cap 14 allows the coolant composition to wet and contact the porous membrane 27 in the housing 12. The release of the microbiocide component from the particles 24 by diffusion through the membrane 27 allows the microbiocide component to be incorporated into and circulated throughout the coolant system (LCMG).

The LCMG-permeable, porous membrane 27 is effectively wetted by the coolant composition (LCMG) and allows microbiocide component to exit the container 10 from the particles 24.

Further, a removable plug 32 is located in a port 34 of the housing body 13. Plug 32 is configured to be removed to allow water or LCMG to be introduced directly into hollow interior 22 of casing 12 via port 34 to contact and wet particles 24 of the microbiocide component contained therein. The introduction of water or LCMG directly into hollow interior 22 is particularly advantageous in situations where the microbiocide component is not wetted by the LCMG in contact with container 10. Other means for introducing water or LCMG into the hollow interior 22 to achieve such pre-wetting of the microbiocide component may be employed. For example, water or LCMG may be injected into the hollow interior 22 via a needle or similar device. Other systems may be employed to allow water or LCMG access to the hollow interior 22 through the membrane. If the other means described is used to pre-wet the microbiocide component in hollow interior 22 or if pre-wetting the microbiocide component is not desired, housing body 13 need not include port 34 and plug 32.

For a container 10 of six (6) inches in length and 1.5 inches in inside diameter, the amount of microbiocide component particles 24 inside the casing is about 186mL or about 175 g. The release of the effective amount of the microbiocide component is initiated in less than about 24 hours.

In one embodiment, container 10 is constructed so as to be non-refillable with microbiocide component. For example, and without limitation, the casing body 13 may be made of a lightweight and/or thin polymeric material (e.g., a thermoplastic polymeric material) that is flexible and/or sufficiently deformable so that when the microbiocide component is released from the casing body into the LCMG, the casing body collapses and maintains the collapsed state. This collapsible casing body effectively prevents the casing body from being refilled with microbiocide.

This collapsible housing body is an essential safety feature according to the invention. As a result, microbiocides are often toxic (e.g., as particles in an undiluted state) and therefore great care must be taken in handling the material to avoid serious injury to the person handling the microbiocide. By using a collapsible casing or casing body, it is apparent that the collapsed casing or casing body cannot be refilled with microbiocide. Thus, the user does not even attempt to refill the casing with the microbiocide, and thus the risk or risk of serious injury or damage by the microbiocide is avoided.

Example 2

As shown in fig. 2, the container 10 (as shown in fig. 2) is positioned in vertical alignment with a cylindrical housing 36 that is provided in a "bypass" configuration with a coolant system, such as a cooling tower system. A representative diameter of the opening 30 in the end cap 14 is 9 mm. As shown, the housing 36 includes a housing body 38 and a housing top 40 that interlock to secure the container 10 within the housing 36. A housing CD ring seal 42 is provided between the housing body 38 and the housing top 40 to seal the interior space 44 of the housing 36.

The coolant (LCMG) flows from the inlet line 46, enters and exits the housing 36 via the tube segment 48, and exits via the exit line 50. While inside the casing 36, the coolant enters the opening or orifice 30 and exits, wetting the membrane 27 and causing the microbiocide component to be released (e.g., by diffusion) from the particles 24 in the casing 12 into the coolant. In general, coolant (LCMG) flows into the inlet line 46 by the action of a coolant pump (not shown) of the coolant system, it being understood that gravity may also function. Further, for example, a coolant filter element (not shown) of conventional and well known design may be located in the exit line 50. It should be appreciated that the filter element may alternatively be located in the inlet line 46. Such alternatives are included within the scope of the invention.

Further, as shown in FIG. 2, the container 10 is positioned in the housing 36 with the opening or aperture 30 facing upwardly toward the tube segment 48. This upward orientation is particularly useful if the particles 24 are coated and/or otherwise include a delayed-release component to control, or at least assist in controlling, the release of the microbiocide component from the container. Alternatively, the container 10 may be positioned in the housing 36 such that the opening or aperture 30 is directed downwardly toward or away from the tube segment 48. This downward orientation is useful when the microbiocide in particle 24 is uncoated or not combined with a delayed release component. Both upward and downward orientations of the container 10, as well as left-right and other orientations of the container 10, are included within the scope of the present invention.

Example 3

Turning now to FIG. 3, an additional container 110 of the present invention is shown. Additional containers 110 are constructed and function substantially similarly to container 10, except as expressly set forth herein.

The container 110 generally comprises a bowl-shaped LCMG-impermeable shell body 113 having a hollow interior 122 filled with particles 124 of an American Food and Drug Administration (FDA) registered microbiocide composition, such as but not limited to DBNPA, and one or more additives effective to benefit the coolant and/or coolant system when released into the coolant. The housing body 113 has a relatively wide open top end 120 in the shape of, for example and without limitation, a circle and an opposing closed end 121. The container 110 further includes a cap member 114 arranged to span and preferably substantially completely cover the open end 120.

The vessel 110 is used, for example, in a coolant (LCMG) line or coolant pump (not shown) of a cooling tower system. For example, the vessel 110 may be placed in a coolant line or in a coolant sump, e.g., in a manner similar to that shown in fig. 2.

In the container 110 illustrated in fig. 3, the cap member 114 is removably secured to the casing body 113 to allow the container 110 to be filled and/or refilled with particles 124 of the microbiocide composition. As shown, the cap member 114 may be recessed from a perimeter or rim 118 of the housing body 113.

Cap member 114 may be secured to inner surface 60 of housing body 113 by means of an elastomeric O-ring 62 or the like.

The cap member 114 includes at least one opening 130, preferably a plurality of openings 130 (e.g., four inlets 130 in the embodiment of fig. 3), to allow a liquid coolant composition (LCMG) in contact with the container 110 to wet the porous membrane layer or pad 127. In this embodiment, the membrane layer 127 is made of nitrocellulose having a pore size of about 8 microns and a benzyltriazole release flux rate (as defined herein) of about 0.025mg/hr./mm²。

The membrane filter component layer or mat is adhered to the inner wall 128 of the cap component 114. Each layer or pad 127 covers a different opening 130 provided in the end cap. The adhesive used may be as described elsewhere herein. A membrane layer or pad 127 is provided for controlling the release of the microbiocide composition from the particles 124 into the coolant.

Further, a removable plug 132 is located in a port 134 of the cap member 114. The plug 132 is configured to be removed to allow water or LCMG to be introduced directly into the hollow interior 122 of the casing 112 via the port 134 to contact and wet the particles 124 of the microbiocide composition contained therein. The introduction of water or LCMG directly into the hollow interior 122 is particularly advantageous in situations where the microbiocide component is not wetted by the LCMG in contact with the container 110.

Container 110 functions in a manner substantially similar to container 10 and is effective to release the microbiocide composition from the container into a coolant (LCMG). In this embodiment, a coolant pump and a coolant filter element may be employed in a manner similar to that set forth in example 2.

Example 4

Fig. 4 and 5 show another container 210 of the present invention that is constructed and functions substantially similar to containers 10 and 110, except as expressly set forth herein.

The container 210 generally includes a bowl-shaped casing body 213 defining a hollow interior 222 for containing particles 224 of a u.s.fda-registered microbiocide component. In addition, aluminum plate member 214 is secured to inner wall 70 of casing body 213 for retaining microbiocide component particles 224 within casing 212. The aluminum plate member 214 includes a plurality of openings 230, for example, four openings 230 as illustrated in fig. 4 and 5. The four openings 230 are arranged in a configuration similar to the manner in which the four openings 130 in the container 110 are arranged.

Four individual support structures 80 are secured to the plate member 214 directly below each of the openings 230. Each of these structures 80 has a through opening 82 and together with the plate member 214 defines a compartment sized to accommodate the porous membrane segment 227 between the plate member 214 and the through opening 82. Thus, the porous membrane segment 227 is press-fitted to the plate member 214. Each of the film segments 227 covers a different one of the openings 230.

In addition, a removable plug 232 is located in a port 234 of housing 212. Plug 232 is configured to be removed, allowing water or LCMG to be introduced directly into hollow interior 222 of casing 212 via port 234, contacting and wetting particles 224 of the microbiocide component contained therein. The introduction of water or LCMG directly into hollow interior 222 is particularly advantageous in situations where the microbiocide component cannot be wetted by the LCMG in contact with container 210.

Container 210 may be used and function in a manner similar to containers 10 and 110 and is effective to release microbiocide component from hollow interior 222 into a coolant (LCMG). In this embodiment, a coolant pump and a coolant filter element may be employed in a manner similar to that set forth in example 2.

Example 5

Fig. 6 shows another container 310 of the present invention that is constructed and functions substantially similar to containers 10, 110, 210, except as expressly set forth herein. The somewhat schematic symbols of fig. 6 are intended to illustrate the salient features of another container 310.

Container 310 generally includes an elongated, cylindrical casing body 313 defining a hollow interior 322 for containing particles 324 of a u.s.fda-registered microbiocide component.

The housing body 313 includes a first end wall 84 that defines a relatively large opening 330. A membrane filter component layer or pad 327 covers the opening 330 and is secured in place (i.e., to the first endwall 84) by adhesive, as set forth elsewhere herein.

The housing body 313 includes an opposing second end wall 86 that defines a relatively smaller second opening 88. Another membrane filter component layer or mat 90 covers the second opening 88 and is secured in place (i.e., to the second end wall 86) by adhesive, as described elsewhere herein.

The ratio of the size or area of opening 330 to the size or area of second opening 88 may be in the range of about 2 or about 4 to about 12 or about 20 (e.g., about 10). In one embodiment, the ratio of the size or area of the opening 330 to the size or area of the second opening 88 may be at least about 5. The ratio of the porosity of the film layer or pad 327 to the porosity of the other film layer or pad 90 may be in the range of about 1 or about 2 to about 10 or about 15.

The size of the second opening 88 is combined with properties of another film layer or pad 90, such as porosity, material type, charge, and the like, such as to allow air to escape the hollow interior 322 via the second opening 88 and to substantially prevent liquids, such as water, aqueous liquids, LCMGs, and the like, from entering the hollow interior 322 through the second opening 88.

The container 310 may be placed in a LCMG, with the opening 330 below the second opening 88 or the opening 330 downstream of the second opening 88 with the LCMG flowing across the container 310. When the container 310 is submerged in the LCMG, the LCMG passes through the opening 330 and the film layer or pad 327 into the hollow interior 322. With the LCMG so introduced into the hollow interior 322, air within the hollow interior exits via the other film layer or pad 90 and the second opening 88. The LCMG and microbiocide component 324 in the hollow interior 322 is substantially prevented from passing through the other film layer or pad 90 and the second opening 88.

Container 310 functions in a manner similar to container 10 to effectively release microbiocide component from the container through opening 330 into the LCMG in which container 30 is present.

Because the container 310 is configured to allow liquid to enter the hollow interior, the microbiocide component is effectively wetted by the liquid, which wetting may advantageously facilitate a controlled or consistent (e.g., substantially constant) release rate of the microbiocide component into the LCMG.

Example 6

Fig. 7 shows a valved container 410 of the present invention which is constructed and functions substantially similarly to containers 10, 110, 210 and 310, except as expressly set forth herein. The somewhat schematic symbol of fig. 7 is intended to illustrate the salient features of valved container 410.

Valved container 410 generally includes an elongated cylindrical casing body 413 defining a hollow interior 322 for containing particles 324 of a u.s.fda-registered microbiocide component.

The housing body 413 includes a first end wall 484 that defines a relatively large opening 430. A membrane filter media layer or pad 427 covers opening 430 and is secured in place (i.e., to first end wall 484) by an adhesive, as set forth elsewhere herein. Film layer or pad 427 is constructed and functions similarly to film pad or layer 327.

The housing body 413 includes an opposing second end wall 486 that defines a second opening 488. A float valve, shown generally at 92, includes a valve port or conduit 94, a valve housing 96, and a ball 98 within the housing. The valve guide 94 and valve housing 96 are secured together. The valve housing 96 and ball 98 are located inside the housing body 413. The valve conduit 94 is secured to the housing body 413, for example, by an interference fit and/or by using an adhesive. As shown in fig. 7, the valve 92 is operatively coupled to the second opening 488 and is separate and apart from the opening 430 and the membrane layer or pad 427 and is not operatively coupled to the opening 430 and the membrane layer or pad 427.

The container 410 may be placed in the LCMG with the opening 430 below the second opening 488 or with the opening 430 downstream of the second opening 488 as the LCMG flows across the container 310. When the container 410 is submerged in the LCMG, the LCMG enters the hollow interior 422 via the valve conduit 94 and the opening 430 and the film layer or pad 327. With the LCMG so introduced into the hollow interior 422, air within the hollow interior exits through the valve conduit 94. Once the LCMG level in the hollow interior 422 reaches a level approximately equal to that of the ball 98, the ball will float upward, abutting the valve conduit 94 and closing the valve 92 to substantially prevent any flow of material into or out of the hollow interior 422 through the valve 92. In other words, the valve 92 is configured to operate automatically, and indeed automatically, without human intervention, in response to the level of LCMG within the hollow interior 422 between the open position and the different closed position. In the open position, the LCMG enters the hollow interior 422 via the valve conduit 94, and air exits from within the hollow interior through the valve conduit 94; in the closed position, any flow of material through the valve 92 into or out of the hollow interior 422 is substantially prevented. Thus, the valve 92 is in the closed position substantially preventing the LCMG and microbiocide component 424 in the hollow interior 422 from exiting the hollow interior 422 through the second opening 488 through the valve 92.

Container 410 functions in a manner similar to container 310 to effectively release microbiocide component (composition) from the container into the coolant (LCMG) via opening 330.

Because container 410 is configured to allow liquid to enter the hollow interior, the microbiocide component is effectively wetted by the liquid, which wetting may advantageously facilitate a controlled or consistent (e.g., substantially constant) release rate of the microbiocide component into the coolant (LCMG).

Example 7

Fig. 8 shows another valved container 510 of the present invention constructed and operative substantially similarly to containers 10, 110, 210, 310 and 410, except as expressly set forth herein. In particular, the valved container 510 is constructed and functions similarly to the valved container 410, except as expressly set forth herein. The somewhat schematic conformity of fig. 7 is intended to illustrate the salient features of another valved container 510.

The primary difference between valved container 510 and valved container 410 is the inclusion of a spring valve (shown generally at 100), while valved container 410 includes a float valve 92.

The spring valve 100 is largely external to the housing body 513 and is in fluid communication with the hollow interior 522 via a second opening 588 in the opposing second end wall 586.

Example 8

Fig. 9 shows an additional valved controlled release system 610 of the present invention. The additionally valved system 610 functions similarly to controlled release systems 10, 110, 210, 310, 410 and 510 except as expressly set forth herein. In particular, except as expressly set forth herein, valved controlled release system 610 is constructed and functions similarly to valved system 410, with the primary difference being that ball float valve 92 in system 410 has been replaced by an integral high precision valve, particularly duckbill valve 102. The duckbill valve 102 is sealed to a suitable valve housing 104 that is fitted (e.g., friction fitted) to the housing body 614.

In this example, the duckbill valve 102 is a one-piece molded elastomeric duckbill valve that opens when the hollow interior 622 of the housing body 613 is at a positive pressure differential relative to the exterior of the housing body 613. As water fills the hollow interior 622, air is free to pass through the opened duckbill valve 102. Once the hollow interior 622 is filled with water and the system 610 is completely submerged in water, the pressure between the hollow interior 622 and the exterior of the housing body 613 equalizes, which causes the duckbill valve to close with the flow of material into or out of the hollow interior 622.

Duckbill valves suitable for use in the system of the present invention are, for example, commercially available from valve resistance Laboratories, Inc (the company headquarters in Yellow Springs, Ohio).

While the invention has been described in terms of various specific examples and embodiments, it is to be understood that the invention is not so limited and can be practiced in various ways within the scope of the following claims.

Claims (9)

1. A container for releasing a microbiocide component in a liquid composition susceptible to undesired microbial growth, said container comprising:

a housing separate and apart from the internal combustion engine filter housing, impermeable to a liquid composition susceptible to undesired microbial growth, and defining a hollow interior, at least one opening, and another opening spaced apart from the at least one opening;

a microbiocide component located in the hollow interior of the casing;

at least one liquid permeable element overlying said at least one opening of said casing and spaced from said another opening not covered by said at least one liquid permeable element, said at least one liquid permeable element effective to provide release of a portion of said microbiocide component into a liquid composition in contact with said casing susceptible to undesired microbial growth; and

a valve operatively coupled to the other opening and separate and spaced apart from the at least one opening; the valve having an open position and a closed position different from the open position; said valve being configured to move between said open position and said closed position different from said open position in direct response to the level of liquid composition susceptible to undesirable microbial growth in said casing when said container releases a microbiocide component in said liquid composition susceptible to undesirable microbial growth; wherein the open position allows air to exit the hollow interior through the further opening via the valve, the closed position substantially preventing any flow of material from exiting the hollow interior through the further opening via the valve.

2. A container as in claim 1 further comprising a port in said casing and a removable plug configured to be placed in said port to close said port and to be removed from said port to allow water or a liquid composition susceptible to undesired microbial growth to be introduced directly into said hollow interior of said casing through said port to contact and wet said microbiocide component.

3. The container of claim 1, wherein the valve is a float valve.

4. A container according to any of claims 1 to 3, wherein the at least one liquid permeable element comprises a membrane mounted to the container.

5. A container as claimed in any one of claims 1 to 3 wherein said microbiocide component is substantially the only active material present in said hollow interior of said casing.

6. A container according to any one of claims 1 to 3 wherein the microbiocide component is hydrophobic.

7. The container of any one of claims 1-3, wherein the microbiocide component is selected from the group consisting of: halogen-containing microbiocides, halogen-releasing microbiocides, thiocarbamate microbiocides, thiocyano microbiocides, sulfate microbiocides, quaternary ammonium microbiocides, metal-containing microbiocides, and mixtures thereof.

8. A method for treating a liquid composition susceptible to undesired microbial growth, the method comprising:

placing the container of any one of claims 1 to 7 in contact with a liquid composition susceptible to undesirable microbial growth; and

releasing a portion of the microbiocide component into the liquid composition in contact with the casing.

9. The method of claim 8 further comprising adding an amount of liquid to the interior of the casing effective to facilitate release of the microbiocide component into the liquid composition after the placing step.