KR20200037747A - Systems and methods for preventing membrane contamination in reverse osmosis purification systems using hydraulic cavitation - Google Patents

Abstract

The present disclosure provides a method for preventing membrane fouling in a fluid processing system having at least one membrane. The method describes the step of hydrodynamic cavitation of the fluid flow, prior to injecting the fluid flow into the fluid handling system and through at least one membrane, and after performing hydrodynamic cavitation in the cavitation reactor, the solid components in the fluid are By altering (i) molecular structure, (ii) charge, or both, the components repel each other and are dispersed around the edge of the membrane to prevent fouling. Also provided is a system for preventing membrane fouling in a fluid processing system having at least one membrane.

Description

Systems and methods for preventing membrane contamination in reverse osmosis purification systems using hydraulic cavitation

Cross reference to related applications

This application claims the benefit of US Provisional Application No. US 62 / 503,313, filed May 8, 2017.

The present invention relates generally to the purification of fluids, and more particularly, to prevent or eliminate membrane fouling and / or scaling associated with fluid handling systems, hydrodynamic cavitation. ), And more specifically, a reverse osmosis (RO) system.

Many different activities of humans cause countless wastes and by-products. As the environmental, health, and industrial impacts of contaminants increase, it is becoming increasingly important to develop new methods to quickly and efficiently remove a wide range of contaminants from contaminated water and other liquids. Purification, as often referred to, aims to reduce or eliminate contaminants and other unsafe materials from the fluid.

There are many purification methods. Some biological treatment techniques include bioaugmentation, bioventing, biosparging, bioslurping, and phytoremediation. Some chemical treatment techniques include ozone and oxygen gas injection, chemical precipitation, membrane separation, ion exchange, carbon absorption, aqueous chemical oxidation, and surfactant enhanced restoration. Some chemical techniques can be implemented using nanomaterials. Physical treatment techniques include, but are not limited to, pump and treatment, air injection, and dual phase extraction.

One embodiment of a purification technique involving the use of membrane technology is reverse osmosis (RO), which is a membrane that allows the passage of water molecules but does not allow the passage of most dissolved salts, organics, bacteria, and pyrogens. It is a water purification technology that uses a semi-permeable membrane to remove ions, molecules, and larger particles from contaminated water by pressing water under pressure through.

RO works by increasing the pressure on the salt side of the RO using a high pressure pump and pressurizing the water across the semipermeable membrane, leaving almost all dissolved salt in the waste stream. Demineralized or deionized demineralized water is referred to as permeate water. Water streams that deliver concentrated contaminants that have not passed through the RO membrane are referred to as waste (or concentrate) streams. As the feed water enters the RO membrane under pressure, water molecules pass through the semipermeable membrane, and salts and other contaminants do not pass, leaving the concentrate stream. In some RO systems, the concentrate stream can be fed back to the RO system through the feed water supply and regenerated through the RO system. Water passing through the RO membrane is referred to as permeate or product water, and generally about 95% to 99% dissolved salt is removed therefrom.

Reverse osmosis can remove many types of dissolved and suspended species, including bacteria, from water and is used in both industrial processes and drinking water production. As a result, the solute remains on the pressurized side of the membrane and the pure solvent can pass through to the other side. To be "selective", these membranes must not allow large molecules or ions to pass through the pores (holes), but smaller components of the solution (eg, solvent molecules) must be able to pass freely. Solutes include silica, barium and other solids several times. Examples of RO membranes are disclosed in U.S. Pat.No. 4,277,344 and describe aromatic polyamide membranes, which are the product of the interfacial reaction between an aromatic polyamine having at least two primary amine substituents and an aromatic acyl halide having at least three acyl halide substituents. do.

RO itself is efficient, but there is a problem due to what is referred to as "membrane fouling" that occurs when contaminants accumulate on the membrane surface, thereby substantially closing the membrane and significantly reducing its purification efficiency. Fouling typically occurs at the front end of the RO system, resulting in a higher pressure drop across the RO system and thus a lower permeation flow rate. Fouling mainly comes from three causes: (i) particles in the feed water (eg, solutes or concentrates); (ii) accumulation of slightly soluble minerals; And (iii) by-products of microbial growth. Due to fouling, the membranes have to be cleaned frequently, which is costly and requires more maintenance, reducing overall system efficiency. In addition, cleaning the membrane is often expensive and shortens the service life of the membrane element. This is especially true if more than one fouling condition prevails that can leave the membrane in an irrecoverable fouled condition, and the only suitable solution is to completely replace the membrane element.

Several pretreatment methods have been proposed using both mechanical and chemical treatments to reduce membrane fouling. For example, an antiscalant can be sprayed into the feed water before reaching the RO membrane. However, this only delays the scale forming process. This delay is sufficient to prevent precipitation of calcium carbonate and calcium sulfate on the membrane surface. Since this delay occurs for a limited period of time, scaling may occur in the system when the operation is stopped. In another embodiment, a dispersant can be sprayed into the feed water. The dispersant prevents fine suspended solids from solidifying and falling off the membrane surface. Proper use of dispersants can minimize fouling due to problematic particulates that are difficult to pre-filter. However, the dispersant has the same problem as the anti-scaling agent. For example, US Pat. No. 6,365,101 discloses a method for inhibiting scale deposits in an aqueous system comprising at least one of a polyvalent metal silicate and a polyvalent metal carbonate, the aqueous system having a pH of at least about 9, and scaling The average particle size of the inhibitor is less than about 3 microns.

Other pretreatment solutions include the use of multi-media filters to help prevent fouling. Multi-media filters typically include three levels of media consisting of anthracite, sand and garnet, with a gravel support layer at the bottom. The filter media arrangement allows for the largest dirt particles to be removed near the top of the bottom of the media, while the smaller dirt particles remain deeper in the media. This allows the entire bottom to act as a filter, allowing much longer filter run times and more efficient particulate removal. In addition, additional methods include the use of microfiltration membranes, water softeners that help exchange scale-forming and non-scale forming ions, sodium hydrogen sulfite insertion, and the use of granular activated carbon.

However, these current pretreatment methods can be costly and fouling still occurs at a rate that can be considered inefficient. Also, regardless of the level of control, no matter how effective the pretreatment and cleaning schedule is, considering the very fine pore size of the RO membrane, fouling will eventually occur to some extent.

Therefore, a post-treatment method was also proposed. For example, as specific coatings for membrane surfaces have been disclosed, methods have been proposed to change the charge on the membrane surface to repel certain solutes. For example, U.S. Pat.No. 6,913,694 describes an optional membrane wherein the hydrophilic coating is a composite polyamide reverse osmosis membrane applied to the polyamide layer of the membrane, and the hydrophilic coating comprises (i) applying a large amount of a polyvalent epoxy compound to the membrane. , The polyvalent epoxy compound comprises at least two epoxy groups, step; And (ii) then crosslinking the polyvalent epoxy compound in such a way to yield a water-insoluble polymer.

In addition, U.S. Patent No. 9,089,820 describes a selective membrane, which is a composite polyamide reverse osmosis membrane having a hydrophilic coating prepared by covalently bonding a hydrophilic compound to a polyamide membrane, wherein the hydrophilic compound is (i) covalently bonded directly to the polyamide membrane. A reactive group that is adapted and is at least one of a primary amine and a secondary amine; (ii) a non-terminal hydroxyl group; And (iii) amide groups. In another embodiment, the hydrophilic compound comprises: (i) a reactive group adapted to be covalently attached directly to a polyamide membrane and being at least one of a primary amine and a secondary amine; (ii) hydroxyl groups; And (iii) an amide group, and the amide group is directly bonded to a hydroxyl group by one of an alkyl group and an alkenyl group.

However, these methods have only achieved moderate success, and can be expensive and may make membrane cleaning more difficult. Accordingly, there is a need for an improved system and method for preventing membrane fouling. One potential solution is to use hydrodynamic cavitation before the contaminated water is supplied through the RO membrane.

In general, cavitation is the formation of a vapor cavity in a liquid, creating a small area free of liquid. In engineering jargon, the term cavitation is used in a narrow sense, that is, to describe the formation of a vapor-filled cavity on or inside a solid boundary created by local pressure reduction caused by the dynamics of a liquid system. .

In hydrodynamic cavitation, decontamination can be achieved by using an underwater spray that causes a hydrodynamic cavitation phenomenon in the liquid. This cavitation phenomenon induces chemical reactions by generating powerful oxidizing and reducing agents and efficiently decomposing and eradicating contaminated organic compounds as well as some inorganic substances. This cavitation phenomenon physically destroys or ruptures the cell wall or outer membrane of microorganisms (eg, E. coli and Salmonella) and larvae (eg, zebra mussel larvae), and also disinfects compounds such as peroxides, hydroxyl radicals, etc. Produced, aid in the eradication of these microorganisms. After destruction of the cell wall or outer membrane, internal cell components are prone to oxidation.

Cavitation technology is used in a wide variety of industrial and ecological purification environments including, but not limited to, agriculture, mining, pharmaceutical, food and beverage manufacturing and processing, fishing, oil and gas production and processing, water treatment and alternative fuels. Due to these broad fields of use, companies are increasingly eager to further develop cavitation technology.

Some embodiments include the use of rotary spray nozzles for cleaning and maintenance purposes disclosed in US Pat. Nos. 5,749,384 (Hayasi et al.) And US Pat. No. 4,508,577 (Conn et al.). Hayashi's device uses a drive mechanism that allows the spray nozzle itself to move upward and downward to rotate and swing. Conn et al. Describe the rotation of the cleaning head including at least two spray forming means for cleaning the inner wall of the conduit.

This current hydrodynamic cavitation technique aims to reduce the particle distribution size of suspended solids, such as those commonly found in RO, in many cases as the cause of membrane fouling. Despite advances in the use of cavitation, little or no remarkable use of cavitation in combination with RO, which can take advantage of cavitation to help prevent membrane fouling. Accordingly, there is a need for new systems and methods for integrating hydrodynamic cavitation into RO to create a more efficient and effective RO process that also reduces the possibility of membrane fouling.

The following summary of the invention is provided to provide a basic understanding of some aspects and features of the invention. This summary is not an extensive overview of the invention, and is not specifically intended to identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented below.

In order to achieve the above and other aspects, and in accordance with the object of the present invention, systems and methods are provided for preventing membrane fouling in a fluid handling system.

In one embodiment of the present invention, a system for preventing membrane fouling, a system for preventing membrane fouling in a fluid processing system having at least one membrane is provided, the system is capable of, into the fluid processing system and at least one membrane Before injecting the fluid flow through, it comprises a hydrodynamic cavitation reactor for cavitation of the fluid flow, and after performing the hydrodynamic cavitation in the cavitation reactor, the solid components in the fluid have their (i) molecular structure, (ii) charge By changing, or both, the ingredients repel each other and are distributed around the edges of the membrane to prevent fouling.

In one embodiment of the present invention, a method is provided for preventing membrane fouling in a fluid processing system having at least one membrane. The method includes hydrodynamic cavitation of the fluid flow prior to injecting the fluid flow into the fluid handling system and through the at least one membrane, after performing hydrodynamic cavitation in the cavitation reactor, solid components in the fluid are By altering (i) molecular structure, (ii) charge, or both, the components repel each other and are dispersed around the edge of the membrane to prevent fouling.

Such methods are useful in fields such as, for example, municipal drinking water, desalination, agriculture, mining, pharmaceuticals, food and beverage manufacturing and processing, fishing, oil and gas production and processing, water treatment and alternative fuels, industrial and ecological purification environments. Do. In particular, the systems and methods are useful in environments using filters with membranes that are susceptible to fouling, such as in reverse osmosis systems and desalination.

Another object of the present invention is to provide a new and improved system and method that is easy and inexpensive to configure.

Other features, advantages, and aspects of the invention will become more apparent and easier to understand from the following detailed description, which should be read in conjunction with the accompanying drawings.

The present invention is shown as an example rather than as a limitation in the drawings of the accompanying drawings, and like reference numerals in the accompanying drawings indicate similar elements, as the drawings:
1 is a schematic diagram of a fluid purification system comprising hydrodynamic cavitation according to an embodiment of the present invention;
2 is a block diagram of a fluid purification system including hydrodynamic cavitation according to an embodiment of the present invention;
3 is a step-by-step flow chart of a method for performing fluid purification including hydrodynamic cavitation according to an embodiment of the present invention;
4 is a front view of a membrane used for reverse osmosis in accordance with one embodiment of the present invention;
5 is a flow diagram illustrating an exemplary method for cavitation based water purification according to one embodiment of the invention;
6 is a schematic diagram of a use case detailing purification in a farm using a fluid purification system according to one embodiment of the present invention;
7 shows data taken from test cases using the systems and methods provided herein to perform purification;
8 is a front view of a reactor plate used in a hydrodynamic cavitation system according to an embodiment of the present invention; And
9 is a schematic diagram of a fluid purification system using hydrodynamic cavitation with an intelligent platform and automated hardware / software device, in accordance with an embodiment of the present invention.
Unless otherwise indicated, drawings are not necessarily drawn to scale.

The invention is best understood by reference to the detailed drawings and descriptions detailed herein.

Embodiments of the present invention are described below with reference to the drawings. However, one of ordinary skill in the art will readily appreciate that the detailed description given herein in connection with these figures is for explanatory purposes as the present invention is extended beyond these limited embodiments. For example, those of ordinary skill in the art may, in view of the teachings of the present invention, implement certain functions of any given detail described herein, beyond the particular implementation choices in the following embodiments shown and described, It should be understood that depending on the needs, a number of alternative and appropriate approaches will be recognized. That is, there are numerous variations and modifications of the present invention that are too many to enumerate but are all suitable within the scope of the present invention.

It should be further understood that the present invention is not limited to the particular methods, compounds, materials, manufacturing techniques, uses, and applications described herein, as they may vary. In addition, it should be understood that the terms used herein are used for the purpose of describing specific embodiments only, and are not intended to limit the scope of the present invention. It should be noted that the singular forms "a", "an" and "the", as used herein and in the appended claims, include multiple quotations, unless the context clearly indicates otherwise. Thus, for example, reference to “element” refers to one or more elements and includes equivalents known to those skilled in the art. Similarly, for other examples, reference to “step” or “means” is a reference to one or more steps or means, and may include sub-steps and auxiliary means. All conjunctions used should be understood in the most comprehensive sense possible. Thus, the word "or" should be understood to have a definition of a logic of "or", rather than a definition of "exclusive or", unless the context clearly requires otherwise. It should also be understood that the structures described herein refer to functional equivalents of such structures. Languages that can be interpreted as expressing approximations should be understood as such, unless the context clearly dictates otherwise.

The term "concentrate stream" as used herein will mean a stream of water that carries concentrated contaminants that have not passed through the RO membrane. Reject water may also be referred to herein as “waste stream”.

The term "contaminated water" as used herein will refer to water molecules combined with dissolved salts, organic matter, bacteria and pyrogens.

As used herein, the term “permeable water” shall mean demineralized water that is dechlorinated or deionized after passing through an RO membrane. Permeated water may also be referred to herein as “treated water”.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although preferred methods, techniques, devices, and materials are described, any method, technology, device, or material similar or equivalent to that described herein can be used in the practice or testing of the present invention. It should also be understood that the structures described herein refer to functional equivalents of such structures. Now, the present invention will be described in detail with reference to its embodiments as shown in the accompanying drawings.

Those skilled in the art, according to the teachings of the present invention, any of the aforementioned steps and / or system modules may be appropriately replaced, rearranged, and removed, and additional steps and / or system modules may be inserted according to the needs of the particular application. Can easily be implemented using any of a wide variety of suitable process and system modules, and not limited to any particular computer hardware, software, middleware, firmware, microcode, etc. something to do. For any of the method steps described herein that can be performed through a computing machine, a typical computer system, when properly constructed or designed, can serve as a computer system in which such aspects of the invention can be implemented.

While exemplary embodiments of the invention are described with reference to the specific industry in which cavitation is used, those skilled in the art will recognize that embodiments of the invention are applicable to any type of application where cavitation is advantageous.

The systems and methods of the present invention prevent membrane fouling and purify the fluid. The system is configured to change the molecular and / or structural properties of concentrates of organic and inorganic species that close or foul the membranes of the filtration system under normal circumstances. The detailed elements and specific embodiments of this decontamination system can be best recognized by further understanding the cavitation phenomena used to induce physical and chemical decontamination reactions. Due to the large pressure drop during the flow, fine bubbles grow in the pressure drop region and collapse in the pressure rise region. When performing cavitation, various molecules in the liquid dissociate to form free radicals, which are powerful oxidizing or reducing agents. For example, in an aqueous liquid, dissociation of water to form hydroxyl radicals occurs due to strong cavitation due to the growth and collapse of fine bubbles. Similar dissociation of other molecules can occur as a result of cavitation in aqueous solutions as well as in non-aqueous liquids and solutions, resulting in radicals that similarly aid the decontamination reaction described herein. Moreover, cavitation generated in any liquid environment will cause physical destruction of contaminants regardless of the production of specific radicals. The method and system of the present invention will be applicable to all fluid environments containing contaminants that are susceptible to degradation through the physical and / or chemical effects of the cavitation used.

The inventors have discovered that, using the systems and methods described herein, the concentrate does not foul the membrane of the RO membrane, as described herein. In addition, we have found that systems and methods are useful in other types of filtration using membrane technology.

Referring now to FIG. 1, a schematic diagram of a fluid purification system comprising hydrodynamic cavitation in accordance with one embodiment of the present invention is generally provided at 100. System 100 defines a variety of outlets 104A-E and RO membrane 160, as well as a hydrodynamic cavitation system 158 coupled with inlet 102. In this embodiment, there is one inlet 102 and five outlets 104A-E, but in alternative embodiments, there may be more or fewer inlets and / or outlets.

With continued reference to FIG. 1, purification channel 101 is configured to use pump 126 to introduce contaminated water into system 100 along the path indicated by 162. The contaminated water passing through the purification channel 101 may initially be raw water, brown water or waste water, may contain sediment, contaminants, etc., and is hydrodynamic by a pump 126 coupled to the hydrodynamic cavitation system 158. It enters the cavitation system 158. Pump 126 is used to supply contaminated water to hydrodynamic cavitation system 158 for treatment.

In this embodiment, there is only one pump 148 configured to operate at high pressure. In alternative embodiments, pump 148 may be operated at different pressures to treat different types of concentrated contaminants (eg, arsenic, lead, radium, cadmium, and zinc) in contaminated water. In another alternative embodiment, more than one pump 148 can be used.

Although a simple rectangular tank is shown in FIG. 1, it should be understood that various sizes, shapes, container locations and a number of components of various sizes can be used.

With continued reference to FIG. 1, now starting at inlet 102, the system includes sensor housing 106, first valve 108, multiple injector coils 110, additive ports 112, and flow meter 114 It includes. As used herein, this region of the system may be referred to as a “pre-cavitation zone” or “mix zone”. The system may further include a first air injector 116 and a second sensor array 118, then a vortex plate 146 and a second air injector 120. Additional sensors (eg, pressure sensor 124) and second valve 122 are also shown. Then, the purge path 101 continues to the outlet 104. As used herein, this region of the system can be referred to herein as a “cavitation zone” 144.

With continued reference to FIG. 1, the sensor housing 106 is positioned adjacent the inlet 102 and is communicatively coupled to the purification path 101, so that the purified contaminated water is tested and monitored before entering the pre-cavitation zone. do. In an alternative embodiment of the present invention, a divergence path 128 and a valve 108 are provided, whereby a sample of purifying fluid is branched for testing. An additional entry path 132 is provided for injecting the test fluid back into the purification channel 101 through a valve 134 (eg, choke valve) coupled to the entry path 132. The sensor housing 106 can include a sensor array used for automation, characterization, and monitoring of the process. For example, the sensor array is a mechanical sensor, an electronic device, an analytical and chemical sensor, a control system, a telemetry system, and a sensor capable of communicating with a programmable logic controller (PLC), described in more detail in connection with FIG. 9. It can include a number of different components, including software.

1, in this embodiment of the present invention, the sensor housing 106 is a mechanical sensor, a flow meter for measuring flow and pressure gauges, pressure, specific gravity, presence of liquid (water level gauge and interface probe), pH, It may include an electronic sensor for measuring various parameters such as temperature and conductivity, and an analytical sensor for measuring chemical parameters such as contaminant concentration. Some embodiments of the analytical sensor include a pH probe, and an optical sensor used for colorimetric measurements. The control system working with the sensor includes a PLC and other electronic microprocessor elements. The control system can receive sensor inputs, process information, and trigger specific actions. These will be described in more detail in connection with FIG. 9.

With continued reference to FIG. 1, a plurality of leads 136 are fluidly coupled to the purification channel 101, and the leads 136 are configured to spray certain materials into the purification channel 101. For example, different types and combinations of precursor compounds in solid, liquid or gas phase can be used depending on the type of fluid treatment process selected, contaminants to be treated, existing water quality, desired water quality, and other parameters. The precursor compound 140 may be pumped or injected into the purification channel 101 through pumps 138A-E. In this embodiment, five pumps 138A-E are used, but in alternative embodiments, more than five pumps may be used. Precursor compound 140 may be a feedstock, but may also include a cartridge that is replaceable for a larger supply of precursor feedstock and various feedstocks, and line feed or other chemical inputs similar thereto.

With continued reference to FIG. 1, exemplary precursor compounds 140 may include halogen salts such as fluorine, chlorine, bromine, iodine, sulfate, sodium, potassium, etc., introduced as a solid or dissolved in water or some other solvent. Contains compounds. Liquid feedstocks, such as ozone, hydrogen peroxide, peracid, brine solution, chlorine solution, ammonia solution, amine, aldehyde, ketone, methanol, chelating agent, dispersant, nitride, nitrate, sulfide, sulfate, etc., soluble in water or some other solvent Can be used. In addition, gas feedstocks such as ozone, air, chlorine dioxide, oxygen, carbon dioxide, carbon monoxide, argon, krypton, bromine, iodine, etc. can be used, each of which can be used in predetermined amounts according to the fluid purification project goals. . For solid compounds, an additive port 112 is shown. Spraying of the desiccant may be performed through manipulation of the valve 142 coupled to the additive port 112.

With continued reference to FIG. 1, a port 112 for introducing an agent into the purge channel 101 can introduce oxidant into the flow-through channel at or near the local flow shrinkage. In the illustrated embodiment, the port can be configured to enable the introduction of oxidant into the fluid at the local flow shrinkage. The port may be configured to introduce oxidant into the purge channel 101, not only at the local flow shrinkage, but also along the region between the local flow shrinkage and the region containing the cavitation bubble where the cavitation bubbles are formed, and including it. Will recognize.

With continued reference to FIG. 1, moving down the purge channel 101, additional sensors, such as the flowmeter 114, are placed along the path. In the pre-cavitation zone, the flow meter is configured to quantify mass fluid movement to enable the PLC to calculate cavitation parameters, as described in more detail with reference to FIG. 9. When the contaminated water enters the cavitation zone 144, various cavitation is performed on the fluid. The cavitation zone 144 includes a first air injector 116 configured to inject air into the purification channel 101; Reactor plate 146; A second air injector 120; And a control valve 124 for controlling the ratio of the flow rate through the cavitation zone 144 and for controlling the average residence time of the fluid in the purification channel 101.

1, the first air injector 116 and the second air injector 120 are vapors in the liquid generated when the fluid receives a rapid pressure change causing the formation of a cavity at a relatively low pressure. It is configured to induce cavitation in the fluid to form a cavity (ie, a small area, bubble or void without liquid). In this way, injectors are used to enhance chemical reactions and propagate reactions as free radicals are formed in the process due to the dissociation of vapors trapped in cavitation bubbles.

With continued reference to FIG. 1, the reactor plate 146 is disposed within the purification channel 101 between the first air injector 116 and the second air injector 120. The reactor plate described in more detail in connection with FIG. 8 is configured to induce additional cavitation in the cavitation zone 144 to allow the presence of large volumes of microbubbles with high volatility. When such microbubbles collapse, an instantaneous pressure of up to 500 atmospheres and an instantaneous temperature of about 5000 degrees K are caused in the fluid. This phenomenon carries out several important chemical reactions: (1) H2O dissociates into OH radicals and H + atoms; (2) the chemical bond of the complex organic hydrocarbon is broken; (3) Before being irradiated downstream by ultraviolet radiation, long-chain chemicals are oxidized to simpler chemical components, accelerating the oxidation process.

1, a butterfly valve in this embodiment, but an additional valve 124, which may include other types of valves in other embodiments, is required to discharge fluid to the outlets 104A-E. It is arranged in the purification channel 101 to drop the pressure. The valve 124 is communicatively connected to the PLC to be completely autonomous, like other valves in the system.

With continued reference to FIG. 1, as fluid passes through the cavitation zone 144, it will be supplied towards the RO membrane 152 through the purge channel 101. The RO pump 160 is coupled to the purification channel 101 to ensure that the RO is produced in the proper amount to occur across the RO membrane 152. When at the outlets 104A-E, fluid passes through the RO membrane 152 to receive RO. As the contaminated water enters the RO membrane 152 under pressure (enough to overcome the osmotic pressure), water molecules pass through the RO membrane 152, salts and other contaminants cannot pass through, and the concentrate stream 162 ) And stored in the concentrate container 156. The permeate passing through the RO membrane 152 passes through the permeate channel 154 and is stored in the permeate container 150.

It has been found that when the fluid passes through the cavitation reactor of Figure 1, the RO filter fouls with a significantly longer membrane life and at a significantly slower rate. In addition, after treatment of 7 MG brine wells per day with drinking water, the system was confirmed to regenerate 55-65% RO concentrate, previously unprocessable without fouling the membrane. Table as shown in Table 1, where each vertical axis represents 1 week:

When RO acted on its own, the filters were not fouled at almost the same ratio, which is s = described with respect to FIGS. 2-4.

Referring now to FIG. 2, a block diagram of a fluid purification and / or processing system including hydrodynamic cavitation according to an embodiment of the present invention is generally shown at 200. A water source 102 is provided that is pumped into the hydrodynamic cavitation reactor 204 or otherwise accommodated by the hydrodynamic cavitation reactor 204. In this embodiment, hydrodynamic cavitation is described. It should be noted, however, that in alternative embodiments, other types of cavitation, such as, but not limited to, acoustic cavitation, can be used in the present system and method. When the fluid is subjected to cavitation in the hydrodynamic cavitation reactor 204, it is in this exemplary embodiment by a second fluid processing system 208 that includes any system that uses a filter with a membrane to purify contaminated water. Is accepted.

One embodiment of wastewater treatment using membrane technology is RO. The RO can use, for example, a membrane that is a spiral winding element comprising a sandwich of two membrane sheets, the inserted permeate carriers are glued together, and the supply spacer between opposing membrane surfaces to complete the membrane package. Is inserted. The membrane package is wound around a perforated central tube through which permeate exits the element. In a typical environment, the membrane will capture permeate that acts as a “fouling layer”. The fouling layer typically consists of microbial communities, salts and minerals such as Al, As, Ch, Co, Mg, BaSO ₄ , O, S, Ni, P, Si, Fe, Ba and Sr, and the like.

After performing the cavitation in the reactor 204, the components of the brine or brown seaweed alter their molecular structure and / or the charge of the sediment molecules, allowing them to “disperse” and not to close or foul the membrane. . In this way, as a pretreatment method and purification technique, cavitation of the fluid after the first flow through the RO membrane or even cavitation of the concentrate reduces the likelihood of the RO membrane closing or fouling. When cavitation is used in the "first pass", RO feedwater is effectively pretreated (for complete or partial removal of potential foulants such as particulates, colloids, and organic materials).

It has been found that the accumulation of the outer phase of the filter consists of a fine white powder containing a small amount of larger aggregates and very similar to the appearance of corn starch. To detect inorganic components present in the sample, power was analyzed via ICP / OES. Considering the results of the solubility test, it was assumed that the powder was a heterogeneous mixture of insoluble salts. Thus, any metallic component detected by elemental analysis can be assumed to be a cationic species in these salt crystals. By far the most abundant metal was found to be calcium and then magnesium and potassium. The molar ratio between these metals was determined as follows: 18: 6: 1 Calcium: Magnesium (mol: mol) and 114: 1 Calcium: potassium (mol: mol). In addition, trace metals (less than 1 ppm each) were detected, such as barium, cobalt, copper, molybdenum, nickel, titanium, vanadium, zinc and silver. Components such as carbon, sulfur, and phosphorus were detected by the instrument to produce a reliable spectrum, but they could not be quantified.

To determine the anionic component of the powder, small samples were analyzed via ion chromatography (IC). Anions were tested for fluoride, chloride, nitrite, sulfate, bromide, and phosphate. Since nitric acid was used to dissolve the powder, nitrate could not be tested.

Based on the data available, it was concluded that the powder consisted primarily of calcium sulfate (> 90%) together with magnesium sulfate and trace amounts of the metals that make up the remaining powder portion. Most of these conclusions have been reached by qualitative means, but are supported by the observed experimental data and the known properties of calcium sulfate. The literature value of the calcium sulfate solubility product (KSP) is 9 x 10-6, consistent with the observation that the powder is slightly soluble in water. In addition, both calcium sulfate and magnesium sulfate appear as white powders, consistent with the physical appearance of the powder analyzed by experiments.

Finally, based on the data from the input flow, there appears to be a known water source for calcium and magnesium entering the hydrostatic cavitation device. Through water quality analysis of the concentrate input flow, it was confirmed that both calcium and magnesium are present at high levels. There appears to be a process in which these two cations react with sulfate to form insoluble aggregates in the hydrostatic cavitation process that helps prevent filter fouling.

Referring now to FIG. 3, a step-by-step flow diagram of a method for performing fluid purification including hydrodynamic cavitation in accordance with one embodiment of the present invention is generally provided at 300. In such a system, contaminated water from water source 302 is pumped into cavitation reactor 304 or is received by cavitation reactor 304. When the RO membrane 306 receives cavitation-contaminated water, it performs reverse osmosis, sends the filtered product water to the production storage tank 308, and contaminates the concentrate flow with a fluid that is not ready for consumption. It is sent to the tank 310. In the sewage tank 310, fluid is precipitated, and particulates are precipitated to the bottom. The fluid with the concentrate is then sent back to the cavitation reactor 304 and subjected to hydrodynamic cavitation as described herein before being reprocessed by the RO membrane 306.

During the test, after the contaminated water passed through the cavitation reactor 304, about 55-65% of the fluid was regenerated and made available for use in the production water, as well as the RO membrane 306 if the contaminated water had not been subjected to cavitation at all It was not fouled as it was. Instead, the membrane pressure was maintained at approximately stable pressure throughout the cycle. Under the “normal” environment of RO, as sediment accumulates, the membrane pressure increases throughout the process. Inspection of the filter showed that when the contaminated water passed through the cavitation reactor 304, the fouling layer did not accumulate on the RO membrane 306, or at least at a much lower rate. The RO membrane 306 in the exemplary embodiment includes a plurality of membranes having pore sizes in the range of 0.0001 μm to 0.001 μm, so that most of the molecules except water can be maintained, and due to the size of the pores, the required osmotic pressure is Much larger than other types of filtration. Thus, particulate accumulation can occur, fouling the RO membrane 306, resulting in loss of production capacity, and sometimes increasing pressure until a failure condition can occur.

With continued reference to FIG. 3, in this exemplary embodiment, contaminated water from water source 302 is sent directly to cavitation reactor 304. However, in an alternative embodiment, the contaminated water from water source 302 can perform RO first and pass through its own RO membrane before being sent to cavitation reactor 304.

Referring now to FIG. 4, a front view of the membrane used for reverse osmosis in accordance with one embodiment of the present invention is generally provided at 400. In this embodiment, films 402 and 404 are shown. Membrane 402 flows into a fluid that has not passed through a cavitation process as described herein, while membrane 404 represents a membrane through which fluid has passed through a cavitation process as described herein. As can be seen, the fouling layer and its fine particles 406 accumulate on the inner portion of the membrane, while in the film 404, minimal fouling layer particulates accumulate on the outer portion 408 of the membrane. This means that an LP film, not an HP film, can be used, which greatly reduces the cost.

Referring now to FIG. 5, a flow diagram is generally provided at 500 illustrating an exemplary method for cavitation based water purification according to one embodiment of the present invention. In this embodiment, the method 500 may include the step 502 of flowing contaminated water through the purification channel starting at the inlet, using a pump to supply water to the purification channel.

With continued reference to FIG. 5, method 500 may further include spraying 504 at least one agent into the permeate using a spray port in fluid communication with the purge channel. Method 500 may further include introducing 506 a burst of air into the fluid using an air actuator in fluid communication with the downstream purge channel from the injection port. Method 500 can further include flowing 508 fluid through the reactor plate to create a vortex.

With continued reference to FIG. 5, method 500 may further include introducing 510 a burst of air into the permeate using an air actuator at a second location in fluid communication with a purge channel downstream from the injection port. have. Method 500 may further include generating 512 at least one and more often a plurality of vortices (vortices) and a cavitation pocket in the permeate in the purification channel.

With continued reference to FIG. 5, the method 500 uses a flow control valve disposed in the purge channel, in electronic communication with the air actuator, and configured to optimize pressure to increase the number of cavitation pockets in the liquid, It may further include the step of adjusting the flow rate of the fluid (516). Method 500 includes outputting 516 the purified permeate to the reverse osmosis purification system, and outputting the permeate from the reverse osmosis system to the production storage tank, and further reprocessing through the purification channel and the reverse osmosis system. For, it may further include flowing 518 the concentrate from the reverse osmosis system to the sewage tank.

Example 1

The examples are for the purpose of illustrating the embodiments and should not be construed as limitations.

Referring now to FIG. 6, an alternative embodiment of a large scale commercial implementation for a purification system using cavitation is generally provided at 600. This optional embodiment contemplates the use of multiple trains of the system described herein. By combining multiple trains together, the concentrates produced in trains a and b are passed through their own reverse osmosis procedure to enable the highest quality purification. It is considered a multi-stage system where the concentrate from the first two stages is the third stage feedwater. Using additional steps, it is possible to increase the regeneration of permeate from the system. In a larger, more selective embodiment, more than two steps can be used before the concentrate is captured and processed.

Starting from the existing train A, contaminated water is collected from the feed water 602. The pump 604 pressurizes the contaminated water towards the reactor 606 and the centrifuge 608 including the hydrodynamic cavitation system. When the contaminated water passes through the centrifuge 608, the solid is converted to a solid storage tank 610, then the rest of the water is pressurized enough to cause reverse osmosis to occur as the water passes through the train A RO membrane 614. It is sent to the train A RO membrane 614 via a pump 612 designed to provide. Upon passing through the RO membrane 614, the permeate is sent through the pump 616 to the permeate storage tank 618, while the concentrate is sent through the pump 620 to the concentrate feedwater 622.

With continued reference to Figure 6, at the same time as the operation of the existing train A, the existing train B also operates. Train B starts when contaminated water is collected from feed water 626. The pump 628 then pressurizes the contaminated water toward the reactor 630 and the centrifuge 632 where hydrodynamic cavitation is performed. The solid is converted to a solid storage tank 636, while the rest of the water is sent through a pump 634 to the train B RO membrane 646. Very similar to train A, pump 634 provides sufficient pressure to allow reverse osmosis to occur as water passes through train B RO membrane 646. Upon passing through the RO membrane 646, the permeate is sent through the pump 624 to the permeate reservoir 640, while the concentrate is sent through the pump 638 to the concentrate feedwater 622.

With continued reference to FIG. 6, when train A and train B are both completed and concentrates from both trains are sent to the concentrate feedwater 622, train C will be performed. The reactor 642 receives the concentrate from the concentrate feedwater 622, which is then passed through a train C RO membrane 648 via a pump 644. As in both train A and train B, pump 644 is designed to generate enough pressure to allow reverse osmosis to occur as the concentrate passes through train C RO membrane 648. The permeate produced by passing through the train C RO membrane 648 is sent through the pump 650 to the permeate reservoir 652, while the remaining concentrate is passed through the pump 654 to the concentrate reservoir 656. Sent.

Referring now to FIG. 7, a table is generally provided at 700 representing data taken from test cases using the systems and methods provided herein to perform purification and cavitation. Table 700 shows the working pressure on a daily basis during the test period. Membrane working pressure is an indicator of the membrane fouling amount. At the start of each test, the working pressure was in the range of 330 to 350 psi. During the first 4 hours of each test the pressure increased to 380 to 390 psi and then remained constant for the rest of the test. If the membrane was gradually fouling, the operating pressure would gradually increase over the course of the test period, so that it would not return to the reference value at the end of each test operation. Since the operating pressure did not increase noticeably during the test period, the test data showed no apparent membrane fouling.

Referring now to FIG. 8, a front view of the reactor plate used in the system according to one embodiment of the present invention is generally provided at 800. Referring again to FIG. 1, a substantially uniformly mixed flow is directed from air injector 116 to reactor plate 146. The reactor plate 146 includes a center opening of a predetermined size through which the fluid passes. Uniform stripes 802 are placed on the face of the reactor plate 146, the number of which is predetermined according to the use case, and is configured to disperse the fluid uniformly. In some embodiments, stripes 802 are circular rings that form each ridge over a predetermined portion of the face of the plate. In the embodiment shown generally at 800, the stripes cover approximately half of the face of the plate facing away from the outer radius. In some optional embodiments, the stripes can act as a seal to the cavitation section. As can be seen in Figure 1, the flange makes the section easily repeatable.

With continued reference to FIG. 8, the vortex generating section 804 is disposed inwardly toward the center of the plate 146 and includes a front edge portion that is first inclined upward and backward, then curved with a continuous convex rear curve. And a valley 808 and a peak 810 that are combined to extend rearward substantially horizontally to the upper edge portion. This peak 810 may be referred to as a “vane”. This morphology ensures that bubbles begin to form at a size small enough to create a long-range hydrophobic action that promotes bubble / particle adhesion, thereby creating an optimal size and number of bubbles in a constantly changing mixing environment. The reactor plate 146 generally increases the amount of hydroxyl radicals capable of decomposing and / or oxidizing organic compounds in the fluid and causing a significant amount of oxidant contained within and / or associated with cavitation bubbles.

The reactor plate 146 can be formed of a material that is relatively impermeable to cavitation, such as a metal alloy, or in some embodiments, an elastic elastomeric material. The reactor plate 146 can be implemented in a variety of different shapes and configurations. For example, the plate can be conical, including a conical surface that leads to vortices, or can be fully periodic, as shown. It should be recognized that other shapes may be used in various ways.

Referring now to FIG. 9, a schematic diagram of a fluid purification system using hydrodynamic cavitation with an intelligent platform and automated hardware / software device, according to one embodiment of the present invention, is generally depicted at 900. “Intelligent platform” generally relates to control devices such as high-performance and high-performance system (eg, PAC system) controllers with programmable redundancy, scalable open architecture, upgradeable CPU, and the like, programmable logic control devices. In addition, in embodiments of the present invention, distributed I / O utilizing PROFINET ^® to maximize efficiency and data propagation has I / O flexibility, ranging from simple discrete to safety and process I / O. It is connected to the range of I / O.

A, PLC (902) as shown in Figure 9 is coupled to a plurality of the controllers (904, 906, 908) electrically connected to each of the various valves and the sensor array (e.g., hardwired, wireless, Bluetooth ^®, etc. ). The PLC 902 is configured to run software that continuously collects data regarding the state of the input device to control the state of the output device. As is known, PLCs typically include a processor (which may include volatile memory), volatile memory containing application programs, and one or more input / output (I / O) ports for connecting to other devices in an automated system. Includes. Additionally, in PLC, it is not affected by contextual knowledge about the processes available as a control level for business analytics applications. The platform may further include higher layer software functions in a surveillance control data collection system (SCADA), manufacturing execution system (MES), or enterprise resource planning (ERP) system. Optionally, the PLC can be an "intelligent PLC" that includes various components that can be configured to provide various enhancements in control applications. For example, in some embodiments, an intelligent PLC includes deep integrated data historian and analysis functions. This technique is particularly suitable for, but not limited to, various industrial automation environments for water purification. In operation, the automation system context information is generated when, for example, the display of the device that generated the data, the structural description of the automation system including the intelligent PLC, the system operation mode indicator, and the contents of the process image area are generated. It may contain one or more of the information about the product. Additionally or alternatively, context-related data may include one or more of a description of the automation software utilized by an intelligent PLC or a status indicator indicating the state of the automation software while the content of the process image area is being generated.

9, the PLC includes a pump 124 and a fluid source 908, a sensor housing 106, a valve 910, a plurality of injector coils 110, an additive port 112, and other sensor arrays ( 114) electronically. An additional down-line controller 904 is communicatively connected to the PLC and further communicates with the additive ports 112 and 138. In an alternative embodiment of the invention, the sensor array 106 is configured to derive all relevant properties of the fluid and send the information to the PLC 902. Based on the properties of the fluid, the PLC is configured to direct the valve 914 to release an agent into the flow that supports the purification process. In some embodiments, PLC 902 is loaded with predetermined information regarding the water quality of the fluid. For example, depending on the type of fluid treatment process selected, contaminants to be treated, existing water quality, desired water quality, and other parameters, fluorine, chlorine, bromine, iodine, sulfate salts entering as a solid or soluble in water or other solvents, Different types and combinations of solid, liquid or gaseous precursor compounds, such as compounds that can include halogen salts such as sodium or potassium, can be used. Additional sensor arrays 912 are provided to test and collect data regarding the treated fluid and to ensure that adequate pressure and flow rates can be provided.

The first air injector 116 communicates with the additional controller 906 and consequently with the PLC 902. In an alternative embodiment of the present invention, PLC 902 is configured to control air pressure in accordance with the degree of cavitation required. In addition, the controller 906 communicates with the reactor plate 146 and baffle (not shown) to rotate and tilt the reactor plate to vary the degree of cavitation. Like the first air injector, the second air injector 120 and the control valve 124 communicate with the controller 906 for similar purposes.

With continued reference to FIG. 9, an additional actuator 918 may be used, and before passing through RO membrane 924 to purified water 926 for end use, optional sensor array 920 and UV reactor 922 ) May be respectively connected to the controller.

The first and second air injectors are configured to induce cavitation in the fluid to form vapor cavities in the fluid (ie, small zones, bubbles or voids without liquid), which can cause the formation of cavities at relatively low pressures. Occurs when a fluid receives a rapid pressure change that causes it. In this way, injectors are used to enhance chemical reactions and propagate reactions as free radicals are formed in the process due to the dissociation of vapors trapped in cavitation bubbles.

The reactor plate 146 is disposed within the line 101 between the first and second air injectors, and communicates with the PLC 902, and the PLC 902 can react with the reactor plate in various directions (e.g., 15 degrees). 146). The reactor plate described in more detail in connection with FIG. 2 is configured in the cavitation zone 144 to induce additional cavitation to allow the presence of large amounts of microbubbles with high volatility.

For example, an additional valve 124, such as a butterfly valve, is placed in the line, thereby lowering the outlet pressure if necessary for the discharge of fluid to the outlet 104. The valve 124 is communicatively connected to the PLC to be completely autonomous, like other valves in the system.

While the present invention has been described in connection with what is currently considered to be the most practical and preferred embodiment, it should be understood that the invention is not limited to these embodiments disclosed herein. Rather, the invention is intended to cover all various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Although specific features of various embodiments of the invention may be shown in some drawings and not in other drawings, this is for convenience only. According to the principles of the present invention, the feature (s) of one drawing may be combined with any or all of the features of any other drawing. As used herein, the words “including”, “comprising”, “having”, and “having” should be interpreted broadly and comprehensively, with any physical interconnection. It is not limited. In addition, any embodiment disclosed herein should not be construed as being the only embodiment possible. Rather, modifications and other embodiments are intended to be included within the scope of the appended claims.

Claims (15)

A method for preventing membrane fouling in a fluid processing system having at least one membrane, comprising:
Prior to injecting a fluid stream into and through the at least one membrane, fluidically cavitation of the fluid stream;
After performing hydrodynamic cavitation in the cavitation reactor, the solid components in the fluid change their (i) molecular structure, (ii) charge, or both, so that the components repel each other and disperse around the edge of the membrane. Prevent fouling,
A method for preventing membrane fouling in a fluid processing system having at least one membrane. According to claim 1,
Pumping the fluid to be treated into the first reverse osmosis train to produce a concentrate,
Wherein the reverse osmosis train comprises a plurality of membranes, and the at least one membrane is one of the plurality of membranes. According to claim 2,
The method further comprising receiving the concentrate in a hydrodynamic cavitation reactor, and introducing a burst of air into the concentrate using an air actuator. According to claim 1,
Further comprising the step of treating the concentrate in the hydrodynamic cavitation reactor, and sending the concentrate through at least one membrane,
Wherein the at least one membrane comprises a first RO membrane or a second RO membrane. According to claim 1,
A method of flowing the fluid through a centrifuge after hydrodynamically caviating the fluid. According to claim 1,
The fluid is a concentrate that is the product of the first RO treatment, and the concentrate is flowed through the cavitation reactor before being flowed through the second RO treatment. The method of claim 6,
After flowing the concentrate through the cavitation reactor, a mixture of solids is produced, the mixture of solids comprising a calcium: magnesium determination of 18.6: 1 and a calcium: potassium determination of 114: 1. A system for preventing membrane fouling in a fluid processing system having at least one membrane, comprising:
A hydrodynamic cavitation reactor for cavitation of the fluid flow, prior to injecting the fluid flow into the fluid processing system and through the at least one membrane,
After performing hydrodynamic cavitation in the cavitation reactor, the solid components in the fluid change their (i) molecular structure, (ii) charge, or both, so that the components repel each other and disperse around the edge of the membrane. Prevent fouling,
A system for preventing membrane fouling in a fluid handling system having at least one membrane. The method of claim 8,
And at least one pump configured to pump fluid to be treated into the first reverse osmosis train to produce a concentrate,
Wherein the reverse osmosis train comprises a plurality of membranes, and the at least one membrane is one of the plurality of membranes. The method of claim 9,
Wherein the reactor receives the concentrate and introduces a burst of air into the concentrate using an air actuator. The method of claim 8,
And a second membrane for treating the concentrate after the hydrodynamic cavitation reactor. The method of claim 8,
And further comprising a centrifuge in fluid communication with the cavitation reactor, configured to remove particles from the fluid. The method of claim 8,
A second fluid dynamic cavitation reactor, and a fluid inlet configured to direct the concentrate through at least one membrane,
Wherein the at least one membrane comprises a first RO membrane or a second RO membrane. The method of claim 13,
After flowing the concentrate through the cavitation reactor, a mixture of solids is produced, the mixture of solids comprising a calcium: magnesium determination of 18.6: 1 and a calcium: potassium determination of 114: 1. The method of claim 8,
Wherein the membrane comprises a low pressure membrane.

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