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CA-3158459-C - BIOFOULING PROTECTION OF ELEVATED VOLUME/VELOCITY FLOWS

CA3158459CCA 3158459 CCA3158459 CCA 3158459CCA-3158459-C

Abstract

Disclosed are devices, methods and/or systems for use in protecting items and/or structures that are exposed to, submerged and/or partially submerged in aquatic environments from contamination and/or fouling due to the incursion and/or colonization by specific types and/or kinds of biologic organisms and/or plants, including the protection from micro- and/or macro-fouling for extended periods of time of exposure to aquatic environments.

Inventors

  • Brian McMurray
  • CLIFF SHARP
  • Mike Termini
  • Emily Ralston
  • Abraham Stephens
  • Jerry Kaster
  • Lindsey Calcutt

Assignees

  • BIOFOULING TECHNOLOGIES, INC.

Dates

Publication Date
20260505
Application Date
20201101
Priority Date
20200506

Claims (20)

  1. EMBODIMENTS IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS: 1. A device for reducing biofouling in a water system, comprising: a treatment unit comprising at least one layer of a permeable fabric structure having an outer surface, an inner surface and a plurality of pores extending therebetween, the permeable fabric structure having a biocide coating on at least one surface which extends at least partially into the plurality of pores, the treatment unit positioned at a water intake location of the water system, wherein all of the water passing through the water system passes through the treatment unit and downstream to the water system, the water requiring an average dwell time to travel through the treatment unit and the water system and be expelled from a water discharge of the water system, wherein the biocide coating elutes a biocide into the water passing through the treatment unit, the biocide contacting at least one fouling organism in the water and reducing fouling on one or more substrate surfaces within the water system for at least the average dwell time.
  2. 2. The device of claim 1, wherein the coated permeable fabric structure within the treatment unit has a permeability with the range of 5 milliliters of water per second per square centimeter to 100 milliliters of water per second per square centimeter.
  3. 3. The device of claim 1, wherein the at least one layer of the permeable fabric structure comprises a 3-dimensional flexible material selected from the group consisting of natural and synthetic fabrics, natural and synthetic membranes, natural and synthetic sheets, and fabrics, membranes, films and sheets made from a combination of natural and synthetic materials. 117
  4. 4. The device of claim 1, wherein a dissolved oxygen content of the water located immediately upstream from the treatment unit is substantially similar to a dissolved oxygen content of the water located immediately downstream from the treatment unit.
  5. 5. The device of claim 1, wherein a dissolved oxygen content of the water located immediately upstream from the treatment unit is substantially higher than a dissolved oxygen content of the water located immediately downstream from the treatment unit.
  6. 6. The device of claim 1, wherein the biocide coating is on an upstream outer surface of the permeable fabric structure.
  7. 7. The device of claim 6, wherein a downstream outer surface of the permeable fabric treatment unit is substantially free of the biocide coating.
  8. 8. The device of claim 1, wherein the water system comprises a once-through system.
  9. 9. The device of claim 1, wherein the water system comprises a recirculation system.
  10. 10. The device of claim 1, wherein the water system comprises a make-up water circuit of a recirculation system.
  11. 11. A method of reducing biofouling on a substrate in a flowing water stream, comprising: applying a coating comprising a biocide to a surface of an enclosure, the enclosure having a plurality of pores extending from the first surface to a second surface of the enclosure, wherein the coating extends into the plurality of pores such that the plurality of pores have an average pre-coating minimum pore opening of at least 25 micrometers and an average post-coating minimum pore opening between 75 and 25 micrometers, placing the coated enclosure in the flowing water stream, wherein the flowing water stream flows through the plurality of pores from the first surface to the second surface and the biocide elutes from the coating into the water stream, the biocide 118 contacting biofouling organisms and reducing biofouling organisms from colonizing on a substrate surface positioned downstream from the coated enclosure.
  12. 12. The method of claim 11, wherein the enclosure comprises a flexible fabric material having a permeability with the range of 5 milliliters of water per second per square centimeter to 100 milliliters of water per second per square centimeter.
  13. 13. The method of claim 11, wherein the flexible fabric material comprises a 3 dimensional flexible material selected from the group consisting of natural and synthetic fabrics, natural and synthetic membranes, natural and synthetic sheets, and fabrics, membranes, films and sheets made from a combination of natural and synthetic materials.
  14. 14. The method of claim 11, wherein a dissolved oxygen content of a portion of the flowing water stream located upstream from the enclosure is substantially similar to a dissolved oxygen content of a portion of the flowing water stream located downstream from the enclosure.
  15. 15. The method of claim 11, wherein a dissolved oxygen content of a portion of the flowing water stream located upstream from the enclosure is substantially higher than a dissolved oxygen content of a portion of the flowing water stream located downstream from the enclosure.
  16. 16. The method of claim 11, wherein the biocide coating is on an upstream outer surface of the enclosure.
  17. 17. The method of claim 16, wherein a downstream outer surface of the permeable fabric filter media is substantially free of the biocide coating.
  18. 18. The method of claim 11, wherein the enclosure is positioned within a water intake of a once-through system.
  19. 19. The method of claim 11, wherein the enclosure is positioned within a water intake of a recirculation system. 119
  20. 20. The method of claim 11, wherein the enclosure is positioned within a make-up water circuit of a recirculation system.

Description

BIOFOULING PROTECTION OF ELEVATED VOLUMENELOCITY FLOWS [0001] [0002] [0003] TECHNICAL FIELD [0004] The invention relates to improved devices, systems and methods for use in protecting items and/or structures that are exposed to, submerged in and/or partially submerged in and/or adjacent to aquatic environments that experience elevated velocity and/or high volume flows from contamination and/or fouling due to the incursion and/or colonization by specific types and/or kinds of biologic organisms. More specifically, disclosed are improved methods, apparatus and/or systems for protecting such structures and/or substrates from micro- and/or macro-fouling for periods of time of exposure to the aquatic environments. [0005] BACKGROUND OF THE INVENTION [0006] The growth and attachment of various marine organisms on structures in aquatic environments, known as biofouling, is a significant problem for numerous industries, including both the recreational and industrial boating and shipping industries, the oil and gas industry, power plants, water treatment plants, water management and control, irrigation industries, manufacturing, scientific research, the military (including the Corps of Engineers), and the fishing industry. Most surfaces, such as those associated with boat hulls, underwater cables, chains and pilings, oil rig platforms, buoys, containment boom systems, fishing nets, piers and docks which are exposed to coastal, harbor or ocean waters (as well as their fresh water counterparts) eventually become colonized by animal species, such as barnacles, mussels (as well as oysters and other bivalves), bryozoans, hydroids, tubeworms, sea squirts and/or other tunicates, and various plant species. Biofouling results from the interaction between various plant and/or animal species with aspects of the substrates to which they ultimately attach, leading to the formation of adhesives that firmly bond the 1 Date Re9ue/Date Received 2022-04-20 biofouling organisms to substrates leading to biofouling. Despite the appearance of simplicity, the process of biofouling is a highly complex web of interactions effected by a myriad of micro-organisms, macro-organisms and the ever-changing characteristics of the aquatic environment. [0007) The economic impacts of biofouling are of paramount concern for many industries. Aside from biofouling induced corrosion of various surfaces exposed to the aquatic environment, another significant economic consequence of biofouling is the formation of biofouling and/or fouling induced scales on heat exchange surfaces and/or other wetted surfaces in many facilities with water consumptions or water movement. For example, large scale water systems are used in a wide variety of processes, and at their most basic these systems rely on heat transfer from a hotter fluid or gas to a colder fluid or gas, with this heat typically travelling through a "heat transfer surface," which is often the metallic walls of heat transfer tubing which separate the hot and cold substances. Often, the fluid will comprise water, which in many cases may be salt water drawn from a bay, sea and/or the ocean, fresh water drawn from a river, lake or well/aquifer or wastewater from various sources. Water is a favorable environment for many life forms, and these fouling organisms will often colonize the wetted surfaces of heat transfer tubing, which can significantly reduce heat transfer rates of the system. In many cases, even thin biofilms formed on a heat transfer surface will significantly insulate this surface, reducing its heat transfer efficiency and greatly increasing the overall operating costs for the system. [0008) A wide variety of methods have been used in attempts to halt and/or reduce biofouling build-up in various water systems. One common attempt at ameliorating biofouling is the use of intake filtration, but the large volumes and/or high-water velocities required for raw water intakes typically limit such efforts to filtering out fish and/or larger debris from the water flow. In addition to filtering, most water systems, especially water systems, treat the raw water flow with some form of oxidizing biocide or other additives, most commonly bleach but also possibly gaseous chlorine, bleach/sodium bromide, chlorine dioxide, monochloramine, and monobromamine. In addition to the high cost of purchasing and/or operating such systems, such caustic substances (which may be strong oxidizing agents in the case of chlorine) can cause deleterious effects far beyond their intended environment of use (i.e., once released they can damage organisms in the surrounding aquatic environment), and many of these substances can enhance corrosion and/or 2 degradation of the very items or related system components they are meant to protect. An additional problem at many facilities, and particularly in the power generation industry, is that regulations developed for and by the United States Environmental Protection Agency (USEPA) typica