HIGHLY POROUS COOLANT CONDITIONING AND REMEDIATION MEDIA

Abstract

The present invention is a solid cooling fluid treatment medium, usually but not always in bead form, suitable to be brought into contact with coolants to remediate and to condition them. A key feature of the medium, typically a polymeric resin, is the presence of relatively very large pores, which are able to capture and remove ultrafine coolant contaminants and breakdown products (such as colloids, soot, coke, organics, scale or other small semi-soluble or insoluble particles). Resins and adsorbents of the prior art have proven unable to remove ultrafine contaminants like these that have a deleterious impact on industrial equipment performance and reliability. The mean pore size diameter of the medium is between about 1,500 and 100,000 and, more preferably, in the range of about 1,500 to about 80,000 .

Claims

1. A polymer resin medium for use in conditioning or remediating a cooling fluid, in which a quantity of polymer resin contains a plurality of pores and further wherein said pores have a mean diameter of between 1,500 and 100,000 as measured by mercury porosimetry.

2. The polymer resin medium according to claim 1, wherein said pores have a mean diameter of between 20,000 and 80,000 as measured by mercury porosimetry.

3. The polymer resin medium according to claim 1, wherein said polymer resin is selected from the group consisting of polystyrene, cross-linked polystyrene, polyurethane, epoxy, polyvinyl, vinyl ester, divinylbenzene or acrylic materials.

4. The polymer resin medium according to claim 1, wherein said pores have a mean diameter of between 8,000 and 60,000 as measured by mercury porosimetry.

5. The polymer resin medium according to claim 1 wherein said polymer resin is in the form of beads.

6. The polymer resin medium according to claim 5 wherein said beads have a mean diameter of between about 100-2,000 m.

7. The polymer resin medium according to claim 6 wherein said beads are suitable for mixing, admixing or layering with other media beads for treatment of cooling fluids.

8. A method of cleaning a quantity of cooling fluid, comprising contacting all or a portion of the coolant to be cleaned with a quantity of polymer medium having pores distributed throughout, wherein ultrafine and colloidal coolant contaminants and breakdown products smaller than 4 m are captured by said pores, said pores' further having a mean diameter of between 1,500 and 100,000 as measured by mercury porosimetry.

9. The method of claim 8, wherein said polymer medium is in the form of beads.

10. The method of claim 8, wherein said polymer medium is selected from the group consisting of polystyrene, cross-linked polystyrene, polyurethane, epoxy, polyvinyl, vinyl ester, divinylbenzene, and acrylic.

11. The method of claim 8, wherein the absorbance of a water-glycol-based cooling fluid can be significantly improved to a value of<0.1000.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1. is a sectional view of an array configured for axial flow.

[0010] FIG. 2. is a sectional view of an array configured for radial flow.

[0011] FIG. 3 is a plan view of a bulk treatment vessel containing the present medium, with an inlet and outlet for fluid flow.

DETAILED DESCRIPTION OF THE INVENTION

[0012] The present inventive ion exchange resins feature unusually large pore sizes, allowing for the, heretofore, impossible capture of fine coolant contaminants and breakdown products (colloids, soot, coke, organics, scale etc.). These contaminants and degradation products are typically less than 1-4 m in size and, therefore, difficult or impossible to remove via sieve-type techniques described within the prior art. By using ion exchange resins with pore sizes on the order of two times or more greater than those described throughout the prior art, the present inventive resins allow for the efficient removal of ultrafine coolant contaminants and breakdown products. These deleterious species enter the relatively larger pores of the inventive ion exchange resins where they are then captured and retained. Typical polymer resins meant for use in the present invention are (without limitation): polystyrene (including cross-linked polystyrenes), polyurethane, epoxy, polyvinyl, vinyl ester, divinylbenzene or acrylic resins of virtually any type as long as they are polymers in the generally understood plastic family. These polymeric resins may be functionalized to form anionic or cationic exchange resins or the polymer may remain unfunctionalized. The use of functionalized anion or cation exchange resins may, however, enhance the solid medium's ability to remove other undesirable contaminants and breakdown products (acids, metals, corrosive anions etc.) from coolants.

[0013] Given the above explanation of how the larger pore inventive resins capture ultrafine insoluble coolant colloid particles etc., the inventors' motivations for employing the unusually porous inventive resins might seem apparent. The use of these relatively large pore-containing ion exchange resins was, however, utterly counterintuitive. Since the ion exchange resins described in the prior art are intended to remove corrosive anions, acids and dissolved metal contaminants, one skilled in the art of coolant treatment would select a resin having a high exchange (acid/metal/anion-removal) capacity. Ion exchange resins with many, smaller pores feature more surface area and, therefore, offer inherently greater contaminant-removal abilities. Intuitively, one skilled in the art of coolant treatment would also select an ion exchange resin with smaller pores and greater surface area to maximize the treatment medium's adsorbing/exchange capacity. By drastically increasing the median pore sizes in the present ion exchange resins, the inventors have acted in complete contradiction with this established wisdom, and have accordingly, overwhelmingly, reduced the inventive ion exchange resin's surface areas. This counterintuitive significant (on the order of two times or more) increase in ion exchange resin pore size has, nevertheless, led to novel and surprisingly improved results to treat the, heretofore, unappreciated and unresolved problem of ultrafine, erosive coolant contaminants and breakdown products (colloids, soot, coke, organics, scale etc.).

[0014] The present invention focuses on the, heretofore, difficult or impossible removal of ultrafine cooling fluid contaminants and breakdown products (colloids, soot, coke, organics, scale etc.) at the expense of the inventive media's acid/metal/anion-removal capabilities. The prior art necessity of contaminant-removal, however, remains important. Fortunately, it is possible to functionalize the present larger-pore ion exchange resins with chemical moieties to address these contaminants. It is equally feasible to combine the present larger-pore ion exchange resins (be they functionalized or not) with other ion exchange resins whose pore sizes are smaller and contaminant-removal capacities are concomitantly greater. This combination of inventive ion exchange resin with more conventional prior art resins may be accomplished by mixing or layering two or more types of ion exchange resin beads. It is generally desirable to combine about 75% (w/w) of the inventive large-pore ion exchange resins with about 25% (w/w) of the traditional ion exchange resins; it is equally tenable that the mixture or layering can be about 50% of each. After one understands the different mechanisms by which the inventive and prior art ion exchange resins work (as described herein), the choice of ratio has to do with the need for anion/metal-removal vs. ultrafine-removal primarily since a reduction in the amount of traditional anion/metal media stoichiometrically reduces the overall ion exchange resin mixture's contaminant-removal capacity concomitantly. As to the inventive ion exchange resins, an inclusion of approximately 75% has been shown to allow for the efficient capture of significant amounts of ultrafine coolant contaminants and breakdown products.

[0015] One skilled in the art of coolant-conditioning and ion exchange will recognize the need to maintain coolant pH within a desirable, very slightly alkaline range (generally pH=8.0-10.5). It is, therefore, imperative that if anionic or cationic forms of the inventive resins are used, that these be balanced by the use of a stoichiometric quantity of resin of the opposite type. If inventive highly porous anion resins are used, this, therefore, requires the complimentary use of cation resin to maintain coolant pH. If inventive highly porous cation resins are used, this, therefore, requires the complimentary use of anion resin to maintain coolant pH. In situations where coolant pH is outside of the desired range, one skilled in the art will be able to modify the ratio of cation/anion resin in such a way as to ensure that coolant pH is restored to the desirable, slightly alkaline range. The combination of anion and cation resins can be achieved by mixing or layering the different resin types. It is equally feasible to treat the cooling fluids of interest with a column/cartridge containing one resin type (anion for instance) followed by a separate column/cartridge containing the complimentary resin type (cation in this instance).

[0016] Clearly, then, the inventive core is the insight into using ion exchange resins having relatively larger (on the order of two times or more) pores to trap ultrafine coolant contaminants and breakdown products including colloids, soot, coke, organics, scale (which have, heretofore, not been adequately quantified and trended but, nevertheless, led to avoidable equipment failures, downtime and premature cooling fluid replacement).

[0017] Referring now to FIG. 1, a sectional view of a portion of pipe 10 typical of a cleaning loop in a coolant system is shown in section with a cartridge 12 in place. The cartridge 12 is a section of the pipe in which two barriers 14, typically a pored screen or mesh, are positioned both upstream and downstream of a quantity of porous beads 16 of solid medium according to the invention. The beads are enlarged in the Figure for illustration purposes and therefore are not shown to scale. The pores or mesh screen holes in the barrier 14 need only to be smaller than the smallest size of the beads 16 to hold them in their position within the cartridge 12. The cartridge 12 can be removed, for replacement of the beads 16, via threaded fasteners 18 or an equivalent means of structural integrity including press-fit, epoxy sealing, welding, robotic sealing or any other means of construction. One or more traditional particulate filters (not shown) can be added at any point along the fluid flow, and are optional. The section of pipe 10 can be placed in any convenient location in a coolant system, preferably in a location of easy access for maintenance (replacement of the solid medium beads). Although not shown in FIG. 1, it is also beneficial to introduce a kidney loop format secondary to a primary filtration system or as part of a primary circulation system, especially for coolant remediation. FIG. 2 shows an alternative configuration for radial flow, with the cartridge 22, barrier 24, beads 26, an inlet pipe 20 and an outlet pipe 28, all analogous to FIG. 1. FIG. 3 is a plan view of a bulk treatment alternative, in which a vessel 30 holds the beads 36 of the present invention, which can be charged to the container via hatch 32, with the fluid flow entering via pipe 31 and exiting via pipe 33. The vessel contains an optional domed lid hatch 32 which can be used as an alternate access point for adding or removing the present beads. Again, in none of these Figures are the beads shown to scale.

[0018] It should be understood that the configuration of FIG. 1 is not shown to scale. Cooling fluid applications can contain from 400 to 200,000 gallons of coolant, typically, or even less or more than that, and the associated media needed according to the invention increases or decreases proportionately. The amount of media needed also varies as a function of the condition of the fluid to be treated. Fluids containing very high levels of contaminants will require concomitantly more media. The types of coolants that can be conditioned or remediated in the present invention (with or without the specific structures shown in FIG. 1) are glycol-based cooling fluids and aqueous mixtures of glycol-based cooling fluids. The present invention, therefore, accommodates a wide variety of media amounts and fluid systems, and those skilled in the art learning from this specification to use the disclosed media with relatively much larger pores will easily be able, without undue experimentation, to determine how much porous resin media to use and how often to replace it. Having said that, a typical installation for a 50:50 water/ethylene glycol system could include, without limitation, two cartridges 1 foot in diameter each and 20 inches in length containing the beads of the present disclosure (any of the 100% inventive beads, 50% inventive beads and 50% prior art beads or other media beads, or the above-described 75% inventive beads and 25% prior art or other media beads) to treat about 6,000 gallons of coolant.

[0019] Although the invention has been described with particularity above, the invention is only to be limited insofar as set forth in the accompanying claims.