WO2021242472A1

WO2021242472A1 - Systems and methods for removing particulates from a liquid feed

Info

Publication number: WO2021242472A1
Application number: PCT/US2021/029849
Authority: WO
Inventors: Lin Zhao; Yu Liu; Jörg THEUERKAUF; Wu Chen
Original assignee: Dow Global Technologies Llc
Priority date: 2020-05-29
Filing date: 2021-04-29
Publication date: 2021-12-02
Also published as: AR122171A1

Abstract

Embodiments of systems for removing particulates include at least one vertical filtration screen configured to sieve particulates greater in size than the plurality of filtration openings from a liquid feed, at least one sparger disposed parallel and upstream of the at least one vertical filtration screen in fluid communication with an air source operable to pass an air feed out of the plurality of sparger openings to create a bubble curtain adjacent to the at least one vertical filtration screen, and a particulate removal system. Embodiments of removing particulates include passing a liquid feed containing particulates through a vertical filtration screen, directing an air feed through a plurality of sparger holes from a sparger to form a bubble curtain across the vertical filtration screen, pumping a stream containing the filtered particulates to a separation device to separate out the filtered particulate, and recycling the filtered stream.

Description

SYSTEMS AND METHODS FOR REMOVING PARTICULATES FROM A LIQUID FEED

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63/032,186, filed on May 29, 2020, the entire disclosure of which is hereby incorporated by reference.

TECHNICAL FIELD

[0002] The present specification generally relates to systems and processes for treating a stream, and in particular, systems and processes for removing floating or sinking particulates from a liquid medium.

BACKGROUND

[0003] In a number of industrial applications where various plastics are produced, particulates of materials used to form the various plastics may inadvertently leave the facility. Occasionally, particulates of these plastics may be found in a process or waste stream leaving the facility. However, environmental concerns have developed with the increasing production of plastics and the presence of particulates in these streams. As the presence of particulates is undesirable, an ongoing need exists for systems and processes to ensure particulates are not present in streams leaving these facilities.

SUMMARY

[0004] Embodiments of the present disclosure are directed to systems and methods of particulate removal that address this need.

[0005] According to one embodiment, a system for removing particulates comprises at least one vertical filtration screen comprising a plurality of filtration openings configured to sieve particulates greater in size than the plurality of filtration openings from a liquid feed, at least one sparger disposed parallel and upstream of the at least one vertical filtration screen, the at least one sparger comprising an elongated body and a plurality of sparger openings spaced along a length of the elongated body, wherein the sparger is in fluid communication with an air source which is operable to pass an air feed out of the plurality of sparger openings to create a bubble curtain adjacent to the at least one vertical filtration screen, and a particulate removal system comprising at least one pump, at least one separation device, a removal pipe fluidly connecting the pump and the separation device, and a return pipe fluidly connected to the separation device, wherein the pump is disposed upstream of the at least one vertical filtration screen and is configured to transfer a particulate containing stream comprising sieved particulates removed from the at least one vertical filtration screen and the bubble curtain, and the separation device is configured to remove particulates from the particulate containing stream. According to one or more embodiments, the separation device may be configured to produce a filtered stream.

[0006] According to another embodiment, a method of removing particulates comprises passing the liquid feed containing particulates through the filtration screen, the filtration screen comprising a plurality of filtration openings that sieves particulates from the liquid feed, directing the air feed through the plurality of sparger holes from the sparger to form the bubble curtain across the filtration screen wherein the bubble curtain concentrates the filtered particulates at the particulate removal pump, producing filtered stream by pumping a stream containing the filtered particulates to the separation device to separate out the filtered particulates, and recycling the filtered stream.

[0007] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows and the claims.

[0008] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a schematic illustration of a perspective view of a system for removing particulates with a submersed pump in accordance with one or more embodiments of the present disclosure;

[0010] FIG. 2 is a schematic illustration of a perspective view of a system for removing particulates with a floating pump in accordance with one or more embodiments of the present disclosure;

[0011] FIG. 3 is a schematic illustration of a sparger in accordance with one or more embodiments of the present disclosure;

[0012] FIG. 4 is a schematic illustration of a perspective view of a system for removing particulates comprising two filtration screens in accordance with one or more embodiments of the present disclosure; and [0013] FIG. 5 is a schematic illustration of a top view of a system for removing particulates comprising two filtration screens in accordance with one or more embodiments of the present disclosure;

DETAILED DESCRIPTION

[0014] As used herein, it is noted that “particulate” or “particulates” is utilized herein to represent both small compounds and minute, separate particles suspended in a liquid medium. In some embodiments, the particulates may have a particle size of less than 10 millimeters. As used herein, “particle size” may refer to the average diameter, measured in millimeters or micrometers, of the particulates.

[0015] Reference will now be made in detail to embodiments of systems for removing floating or sinking particulates from a liquid feed.

[0016] Although the concepts of the present disclosure are described herein with primary reference to remove particulates of materials used to form various plastics, it is contemplated that the concepts will enjoy applicability to any type of particulate and to any liquid feed. For example, and not by way of limitation, it is contemplated that the concepts of the present disclosure will enjoy applicability to open water streams.

[0017] Referring to the embodiment of FIG. 1, a system 100 for removing particulates comprises at least one vertical filtration screen 101 comprising a plurality of filtration openings 102 configured to sieve particulates greater in size than the plurality of filtration openings 102 from a liquid feed 103 and at least one sparger 104 disposed parallel and upstream of the at least one vertical filtration screen 101. The at least one sparger 104 comprises an elongated body and a plurality of sparger openings spaced along a length of the elongated body, wherein the sparger 104 is in fluid communication with an air source which is operable to pass an air feed out of the plurality of sparger openings to create a bubble curtain adjacent to the at least one vertical filtration screen 101. The system 100 further comprises a particulate removal system comprising at least one pump 105, at least one separation device 106, a removal pipe 107 fluidly connecting the pump and the separation device, and a return pipe 108 fluidly connected to the separation device 106. The pump 105 may be disposed upstream of the at least one vertical filtration screen 101 and may be configured to transfer a particulate containing stream 115 comprising sieved particulates removed from the at least one vertical filtration screen 101 and the bubble curtain.The separation device 106 may be configured to remove particulates from the particulate containing stream 115 to produce a filtered stream 118. That is, the plurality of filtration openings 102 may sieve particulates comprising a greater diameter than the plurality of filtration openings 102.

[0018] As used herein, “liquid feed” may comprise one or more liquid components such as water, oil, a waste stream, or any other suitable liquid. According to one or more embodiments, the liquid feed may be delivered in a channel 109 upstream of the vertical filtration screen 101. It is also envisioned that the liquid feed may be delivered using other means, such as, but not limited to, a process line.

[0019] As used herein, “filtration screen” may refer to any porous type of material that prevents particles that are larger than the pore openings, or “filtration openings,” from passing through the material. That is, the vertical filtration screen 101 may effectively sieve particles that are larger than the filtration openings 102 of the vertical filtration screen 101. According to one or more embodiments, the vertical filtration screen 101 may be constructed from metal or plastic, such as, but not limited to nylon or vinyl. According to one or more embodiments, the vertical filtration screen 101 may be vertical or substantially vertical. That is, the vertical filtration screen 101 may have an alignment such that the top is directly above the bottom. In other embodiments, the top of the vertical filtration screen 101 may be offset from the bottom of the vertical filtration screen 101.

[0020] The arrangement of the at least one vertical filtration screen 101 may be in any geometric fashion. As shown in FIG. 1 and FIG. 2, the at least one vertical filtration screen 101 is vertical and arranged in a “V.” However, in other embodiments, it is envisioned that other geometries of the at least one vertical filtration screen 101 may be employed, such as, but not limited to, a linear geometry, a curved geometry, a “U” type, or any combination of these.

[0021] As used herein, “sparger” may refer to a device or component operable to pass a gas into a liquid. Referring to FIG. 3, the sparger 104 may comprise an elongated body 301 and a plurality of sparger openings 302. The elongated body 301 may comprise any variety of geometrical cross- sectional areas, such as, but not limited to, rectangular, circular, cylindrical, or triangular. The plurality of sparger openings 302, which may also comprise any variety of geometrical cross- sectional areas, such as, but not limited to, rectangular, circular, cylindrical, or triangular, may be operable to pass a gas into the liquid feed. As shown in FIG. 3, the plurality of sparger openings 302 may be positioned uniformly along the elongated body 301 of the sparger 104. It is also envisioned that the plurality of sparger openings 302 may be positioned randomly along the elongated body 301 of the sparger 104.

[0022] Referring to the embodiments of FIG. 1, the sparger 104 may be disposed parallel and upstream of the at least one vertical filtration screen 101. In other embodiments, the sparger 104 may be disposed in other locations, such as locations not parallel to the at least one vertical filtration screen 101 or locations not upstream to the at least one vertical filtration screen 101. However, positioning the sparger 104 parallel and upstream of the at least one vertical filtration screen 101 may recognize the greatest effect and most efficient use of the sparger 104.

[0023] Referring to FIG. 3, the elongated body 301 of the sparger 104 may comprise an inside diameter of from Vi6 inch to 8 inch. For example, the elongated body 301 of the sparger 104 may comprise an inside diameter of from Vi6 inch to s inch, from i6 inch to ^lk inch, from i6 inch to ^lh inch, from i₆ inch to 1 inch, from i₆ inch to 2 inch, from i₆ inch to 4 inch, from i₆ inch to 6 inch, from Vs inch to ^lk inch, from Vs inch to V₂ inch, from Vs inch to 1 inch, from Vs inch to 2 inch, from Vs inch to 4 inch, from Vs inch to 6 inch, from Vs inch to 8 inch, from ^l inch to V₂ inch, from V₄ inch to 1 inch, from V₄ inch to 2 inch, from V₄ inch to 4 inch, from V₄ inch to 6 inch, from V₄ inch to 8 inch, from V₂ inch to 1 inch, from V₂ inch to 2 inch, from V₂ inch to 4 inch, from V₂ inch to 6 inch, from V₂ inch to 8 inch, from 1 inch to 2 inch, from 1 inch to 4 inch, from 1 inch to 6 inch, from 1 inch to 8 inch, from 2 inch to 4 inch, from 2 inch to 6 inch, from 2 inch to 8 inch, from 4 inch to 6 inch, from 4 inch to 8 inch, or from 6 inch to 8 inch.

[0024] The plurality of sparger openings 302 may comprise an opening size of from V64 inch to 2 inch. For example, the plurality of sparger openings may comprise an opening size of from V64 inch to V₃₂ inch, from V₆₄ inch to Vi₆ inch, from V₆₄ inch to Vs inch, from V₆₄ inch to V₄ inch, from V₆₄ inch to V₂ inch, from V₆₄ inch to 1 inch, from V₃₂ inch to Vi₆ inch, from V₃₂ inch to Vs inch, from V₃₂ inch to V₄ inch, from V₃₂ inch to V₂ inch, from V₃₂ inch to 1 inch, from V₃₂ inch to 2 inch, from Vi₆ inch to Vs inch, from Vi₆ inch to V₄ inch, from Vi₆ inch to V₂ inch, from Vi₆ inch to 1 inch, from Vi₆ inch to 2 inch, from Vs inch to V₄ inch, from Vs inch to V₂ inch, from Vs inch to 1 inch, from Vs inch to 2 inch, from V₄ inch to V₂ inch, from V₄ inch to 1 inch, from V₄ inch to 2 inch, from V₂ inch to 1 inch, or from V₂ inch to 2 inch. [0025] The plurality of sparger openings 302 may be spaced along a length of the elongated body 301 at increments from Vi₆ inch to 4 inch. For example, the plurality of sparger openings may be spaced along a length of the elongated body at increments from Vi₆ inch to Vs inch, from i₆ inch to ^l inch, from i₆ inch to V2 inch, from i₆ inch to 1 inch, from i₆ inch to 2 inch, from i₆ inch to 3 inch, from Vs inch to ^lk inch, from Vs inch to V2 inch, from Vs inch to 1 inch, from Vs inch to 2 inch, from Vs inch to 3 inch, from Vs inch to 4 inch, from ^l inch to V2 inch, from ^l inch to 1 inch, from ^l inch to 2 inch, from V4 inch to 3 inch, from V4 inch to 4 inch, from V2 inch to 1 inch, from V2 inch to 2 inch, from V2 inch to 3 inch, from V2 inch to 4 inch, from 1 inch to 2 inch, from 1 inch to 3 inch, from 1 inch to 4 inch, from 2 inch to 3 inch, from 2 inch to 4 inch, or from 3 inch to 4 inch.

[0026] According to one or more embodiments, the air source (not shown) may be any supply of air operable to supply pass adequate air to the sparger 104. The air source may be for example, but is not limited to, an air compressor or an air pump.

[0027] The air source may pass the air feed out of the plurality of sparger openings at a pressure of greater than 5 psi. For example, air source may pass the air feed out of the plurality of sparger openings at a pressure of greater than 10 psi, greater than 20 psi, greater than 30 psi, greater than 40 psi, greater than 50 psi, greater than 60 psi, greater than 70 psi, greater than 80 psi, greater than 90 psi, or greater than 100 psi. The air source may pass the air feed out of the plurality of sparger openings at a rate of greater than 1 standard cubic foot per minute (scfm). For example, the air source may pass the air feed out of the plurality of sparger openings at a rate of greater than 2 scfm, greater than 5 scfm, greater than 10 scfm, greater than 15 scfm, greater than 20 scfm, greater than 25 scfm, or greater than 30 scfm.

[0028] As used throughout the present disclosure, “bubble curtain” may refer to a series of bubbles that act as a barrier as they rise from the bubble curtain source, such as, but not limited to, a sparger. Bubble curtain may be used interchangeably with pneumatic barrier. Bubble curtains may, for example, break the propagation of waves or the spreading of particles and other contaminants. Referring again to FIG. 1, the bubble curtain may prevent particulates from contacting the vertical filtration screen 101, from accumulating in and on the vertical filtration screen 101, or a combination of these. Therefore, the bubble curtain may prevent the vertical filtration screen 101 from fouling by particulates or biological growths in the liquid feed. In some embodiments, the use of the bubble curtain may enable using a vertical filtration screen 101 comprising filtration openings 102 larger in size than the particulates to be removed. Without being bound to any particular theory, the bubble curtain may prevent these fine particulates from contacting the vertical filtration screen 101 and, therefore, may prevent fine particulates from passing the vertical filtration screen 101. A vertical filtration screen with larger filtration openings

102 may be desirable to increase the throughput of the liquid feed 103, while not having to sacrifice filtration and particulate removal properties. Additionally, the bubble curtain may direct some floating particulates, not otherwise already on the surface, to the surface of the liquid feed

103 for easy removal. In some embodiments, the bubble curtain may run continuously. In other embodiments, the bubble curtain may be used intermittently, or in series, to remove particulates from the vertical filtration screen 101 as desired.

[0029] As further demonstrated in the Examples, the bubble curtain may be effective to increase the separation efficiency of particulates with a smaller diameter than the opening size the filtration openings 102. In embodiments where the filtration openings 102 comprise a circular opening, the opening size of the filtration openings 102 may be measured by the diameter of the circular opening. In embodiments where the filtration openings 102 comprise a non-circular opening, the opening size of the filtration openings 102 may be measured by the largest span of the non-circular opening. Without being bound to any particular theory, the bubble curtain may prevent particulates with a smaller diameter than the opening size of the filtration openings 102 from coming into contact with the vertical filtration screen 101. Therefore, a portion of the particulates with a smaller diameter than the opening size of the filtration openings 102 may be held upstream of the vertical filtration screen 101 by the bubble curtain, such that the particulates may be removed from the liquid feed 103 without passing across the vertical filtration screen. In embodiments, the bubble curtain may increase the separation efficiency of the particulates in the liquid feed 103 by greater than 1%, greater than 2%, greater than 3%, greater than 4%, greater than 5%, such as greater than 6%, greater than 7%, greater than 8%, greater than 9%, greater than 10%, greater than 15%, greater than 20%, or greater than 25%. As used herein, “separation efficiency” may refer to the mass percent of particulates that are sieved by the vertical filtration screen 101 or retained upstream of the vertical filtration screen 101 by the bubble curtain.

[0030] Referring again to the embodiment of FIG. 1, the pump 105 drives off a particulate containing stream 115 comprising particulates dislodged from the vertical filtration screen 101 by the bubble curtain. In order for the system 100 to be a self-cleaning and continuous operation, the pump 105 may remove a portion of the liquid feed 103 and direct that portion of the liquid feed 103 to the separation device 106 to remove the particulates. That is, the pump 105 may be operable to remove a portion of the particulates upstream of the vertical filtration screen 101 such that the filtration openings 102 of the vertical filtration screen 101 may remain unobstructed. Therefore, the vertical filtration screen 101 may be able to continuously process the liquid feed 103 and to continue sieving particulates from the liquid feed 103, as the pump 105 remove particulates which have been sieved from the liquid feed 103. Without being bound to any particular theory, without continuously or periodically removing particulates from the liquid feed 103, the vertical filtration screen 101 may become obstructed due to a buildup of sieved particulates.

[0031] The pump 105 may be configured to transfer a particulate containing stream 115 to the separation device 106 at a flow rate greater than 1 gallons per minute (gpm). As used throughout the present disclosure, pump suction rate may refer to the flow rate of the particulate containing stream 115 that the pump 105 is configured to transfer. For example, the pump 105 may be configured to transfer a particulate containing stream 115 to the separation device at a flow rate greater than 1 gpm, greater than 5 gpm, greater than 10 gpm, greater than 15 gpm, greater than 20 gpm, greater than 25 gpm, greater than 30 gpm, greater than 35 gpm, greater than 40 gpm, greater than 45 gpm, greater than 50 gpm, greater than 60 gpm, greater than 70 gpm, greater than 80 gpm, greater than 90 gpm, or greater than 100 gpm.

[0032] The return pipe 108 may be configured to transfer the filtered stream 118 to be combined with the liquid feed 103 upstream of the at least one vertical filtration screen 101. In other embodiments, the filtered stream 118 may be combined with the liquid feed 103 downstream of the at least one vertical filtration screen 101. In alternative embodiments, the filtered stream 118 may be used in various processes not associated with the system for removing particulates.

[0033] The separation device 106 may comprise, but is not limited to, at least one separation screen 110. The separation device 106 may comprise a container with at least one separation screen 110 to filter particulates from the particulate containing stream 115. The separation device 106 may comprise, but is not limited to, a shaking screen separator, a dewatering box, a dewatering filter, a sludge bag, or a geotextile tube. [0034] Referring specifically to FIG. 1, the pump 105 may be a submersible pump. A submersible pump is a device which may have a hermetically sealed motor close-coupled to the pump body. A close-coupled pump refers to a pump comprising a single shaft that extends from the motor to the pump body through an opening in the cover plate. The whole assembly of the submersible pump may be submerged in the liquid feed 103 to be pumped. Referring specifically to FIG. 2, in one or more embodiments, the pump 105 may be a floating pump, such as, but not limited to, a sump pump or a skimmer. Alternatively, the pump 105 may be a frame mounted pump. In yet other embodiments, the pump 105 may be a screw conveyor or an auger conveyor.

[0035] Referring now to FIG. 4 and 5, according to one or more embodiments, the system 200 may comprise two vertical filtration screens 101, 201. In such an embodiment, the vertical filtration screens 101, 201 may be arranged such that a space exists between each of the vertical filtration screens 101, 201. A first vertical filtration screen 101 may be disposed upstream while a second vertical filtration screen 201 may be a certain distance downstream from the first vertical filtration screen 101. The two vertical filtration screens 101, 201 may comprise the same screen geometry or may comprise different screen geometries. In some embodiments, the second vertical filtration screen 201 may also have a second sparger 204, featuring the same characteristics of the first sparger. Any number of vertical filtration screens 101, such as three vertical filtration screens, four vertical filtration screens, five vertical filtration screens, and so on is contemplated.

[0036] According to one or more embodiments, the two vertical filtration screens 101, 201 comprise a first set of filtration openings 102 and a second set of filtration openings 202, which are of differing sizes. In some embodiments, the first vertical filtration screen 101 upstream of the second vertical filtration screen 201 may comprise a first set of filtration openings 102 having an opening size that are larger than the opening size of the second set of filtration openings 202 of the second vertical filtration screen 201 downstream of the first vertical filtration screen 101. Such a configuration may effectively sieve larger particulates at the first vertical filtration screen 101 and smaller particulates at the second vertical filtration screen 201. Alternatively, the first vertical filtration screen 101 upstream of the second vertical filtration screen 201 may comprise first set of filtration openings 102 having an opening size that are smaller than the opening size of the second set of filtration openings 202 of second vertical filtration screen 201 downstream of the first vertical filtration screen 101. In some embodiments, the two vertical filtration screens 101, 201 may comprise filtration openings 102, 202 of the same opening size. [0037] In some embodiments, the second vertical filtration screen 201 may comprise a second sparger 204 and an additional particulate removal system, as previously described herein. The first sparger 104 for the first vertical filtration screen 101 and the second sparger 204 for the second vertical filtration screen 101 may operate independently, in tandem, or with some overlap. For example, overlap may mean that the first sparger 104 operates and prior to shutting down, the second sparger 204 begins to operate. Further, in some embodiments, air source of the spargers 104, 204 may pass the air feed out of the plurality of sparger openings of each sparger 104, 204 at the same rates, or at different rates.

[0038] According to one or more embodiments, the pump 105 of first vertical filtration screen 101 may operate with the same process conditions as the pump 205 of the second vertical filtration screen 201. In other embodiments, the pumps 105, 205 associated with each vertical filtration screen 101, 201 may comprise a different type of pump 105, 205 and may operate with different process conditions. For example, each pump 105, 205 may comprise a different pump suction rate.

[0039] The first set of filtration openings 102 of the first vertical filtration screen 101 may comprise an opening size of 20 micrometers to 10 millimeters. As used herein, filtration openings 102, 202 are measured by the opening size of the filtration opening 102. For example, the filtration openings 102 may comprise an opening size of 20 micrometers to 30 micrometers, 20 micrometers to 40 micrometers, 20 micrometers to 50 micrometers, 20 micrometers to 60 micrometers, 20 micrometers to 70 micrometers, 20 micrometers to 80 micrometers, 20 micrometers to 90 micrometers, 20 micrometers to 100 micrometers, 20 micrometers to 0.5 millimeters, 20 micrometers to 1.0 millimeters, 20 micrometers to 2.0 millimeters, 20 micrometers to 3.0 millimeters, 20 micrometers to 4.0 millimeters, 20 micrometers to 5.0 millimeters, 20 micrometers to 6.0 millimeters, 20 micrometers to 7.0 millimeters, 20 micrometers to 8.0 millimeters, 20 micrometers to 9.0 millimeters, 20 micrometers to 10.0 millimeters. The filtration openings 102 may comprise an opening size of 40 micrometers to 50 micrometers, 40 micrometers to 60 micrometers, 40 micrometers to 70 micrometers, 40 micrometers to 80 micrometers, 40 micrometers to 90 micrometers, 40 micrometers to 100 micrometers, 40 micrometers to 0.5 millimeters, 40 micrometers to 1.0 millimeters, 40 micrometers to 2.0 millimeters, 40 micrometers to 3.0 millimeters, 40 micrometers to 4.0 millimeters, 40 micrometers to 5.0 millimeters, 40 micrometers to 6.0 millimeters, 40 micrometers to 7.0 millimeters, 40 micrometers to 8.0 millimeters, 40 micrometers to 9.0 millimeters, 40 micrometers to 10.0 millimeters, 100 micrometers to 0.5 millimeters, 100 micrometers to 1.0 millimeters, 100 micrometers to 2.0 millimeters, 100 micrometers to 3.0 millimeters, 100 micrometers to 4.0 millimeters, 100 micrometers to 5.0 millimeters, 100 micrometers to 6.0 millimeters, 100 micrometers to 7.0 millimeters, 100 micrometers to 8.0 millimeters, 100 micrometers to 9.0 millimeters, or 100 micrometers to 10.0 millimeters.

[0040] The second set of filtration openings 202 of the second vertical filtration screen 201 may comprise a size of 20 micrometers to 10 millimeters. For example, the filtration openings 202 may comprise an opening size of 20 micrometers to 30 micrometers, 20 micrometers to 40 micrometers, 20 micrometers to 50 micrometers, 20 micrometers to 60 micrometers, 20 micrometers to 70 micrometers, 20 micrometers to 80 micrometers, 20 micrometers to 90 micrometers, 20 micrometers to 100 micrometers, 20 micrometers to 0.5 millimeters, 20 micrometers to 1.0 millimeters, 20 micrometers to 2.0 millimeters, 20 micrometers to 3.0 millimeters, 20 micrometers to 4.0 millimeters, 20 micrometers to 5.0 millimeters, 20 micrometers to 6.0 millimeters, 20 micrometers to 7.0 millimeters, 20 micrometers to 8.0 millimeters, 20 micrometers to 9.0 millimeters, 20 micrometers to 10.0 millimeters. The filtration openings 202 may comprise an opening size of 40 micrometers to 50 micrometers, 40 micrometers to 60 micrometers, 40 micrometers to 70 micrometers, 40 micrometers to 80 micrometers, 40 micrometers to 90 micrometers, 40 micrometers to 100 micrometers, 40 micrometers to 0.5 millimeters, 40 micrometers to 1.0 millimeters, 40 micrometers to 2.0 millimeters, 40 micrometers to 3.0 millimeters, 40 micrometers to 4.0 millimeters, 40 micrometers to 5.0 millimeters, 40 micrometers to 6.0 millimeters, 40 micrometers to 7.0 millimeters, 40 micrometers to 8.0 millimeters, 40 micrometers to 9.0 millimeters, 40 micrometers to 10.0 millimeters, 100 micrometers to 0.5 millimeters, 100 micrometers to 1.0 millimeters, 100 micrometers to 2.0 millimeters, 100 micrometers to 3.0 millimeters, 100 micrometers to 4.0 millimeters, 100 micrometers to 5.0 millimeters, 100 micrometers to 6.0 millimeters, 100 micrometers to 7.0 millimeters, 100 micrometers to 8.0 millimeters, 100 micrometers to 9.0 millimeters, or 100 micrometers to 10.0 millimeters.

[0041] In embodiments with two vertical filtration screens 101, the first set of filtration openings 102 of the first vertical filtration screen 101 and the second set of filtration openings 202 of the second vertical filtration screen 201 may comprise a filtration opening size ratio such that the first vertical filtration screen 101 comprises the first set of filtration openings 102 with an opening size that are 110% of the opening size of the second set of filtration openings 202 of the second vertical filtration screen 201, such as 125%, 150%, 175%, 200%, 225%, 250%, 275%, or 300% of the opening size of the second set of filtration openings 202 of the second vertical filtration screen 201.

[0042] Referring to FIGS. 1 , 2, 4, and 5 and as previously described herein, according to another embodiment of the present disclosure, a method of removing particulates comprises passing the liquid feed 103 containing particulates through the vertical filtration screen 101, the vertical filtration screen 101 comprising a plurality of filtration openings 102 that sieves particulates from the liquid feed 103, directing the air feed through the plurality of sparger holes from the sparger 104 to form the bubble curtain across the vertical filtration screen 101 wherein the bubble curtain concentrates the filtered particulates at the pump 105, producing the filtered stream 118 by pumping a particulate containing stream 115 to the separation device 106 to separate out the filtered particulates, and recycling the filtered stream 118.

[0043] According to one or more embodiments, the method may further comprise recycling the filtered stream 118 to be combined with the liquid feed 103. The filtered stream 118 may be passed through the return pipe 108 and combined with the liquid feed 103 upstream of the vertical filtration screen 101. In other embodiments, the filtered stream 118 may be combined with the liquid downstream of the first vertical filtration screen 101 or the second vertical filtration screen 201.

[0044] Referring again to the embodiment of FIG. 4 and 5, the system 200 may comprise a second vertical filtration screen 201 comprising a plurality of second set of filtration openings 202 that sieves particulates from the liquid feed 103. In operation, the liquid feed 103 passes through the second vertical filtration screen 201 after passing through the first vertical filtration screen 101 upstream of the second vertical filtration screen 201.

[0045] Process conditions for the method of removing particulates, as disclosed herein, will now be described in greater detail. According to one or more embodiments, the liquid feed 103 may comprise a flow rate greater than 10 gallons per minute (gpm). For example, the liquid feed 103 may comprise a flow rate greater than 50 gpm, greater than 100 gpm, greater than 250 gpm, greater than 500 gpm, greater than 750 gpm, greater than 1,000 gpm, greater than 2,000 gpm, greater than 3,000 gpm, greater than 4,000 gpm, greater than 5,000 gpm, greater than 7,500 gpm, greater than 10,000 gpm, greater than 15,000 gpm, greater than 20,000 gpm, greater than 30,000 gpm, or greater than 40,000 gpm. It is envisioned that there is no upper limit to flow rate of the liquid feed 103. However the maximum flow rate, the ability to efficiently remove particulates form the liquid feed 103 may further depend on the other components of the system 100, 200.

[0046] According to one or more embodiments, a ratio of the liquid feed 103 (gallons per minute) to the air feed (standard cubic feet per minute) may be from 150: 1 to 1500: 1. For example, the a ratio of the liquid feed 103 to the air feed may be from 150:1 to 300:1, from 150:1 to 450:1, from 150:1 to 600:1, from 150:1 to 750:1, from 150:1 to 900:1, from 150:1 to 1000:1, from 150:1 to 1100:1, from 150:1 to 1200:1, from 150:1 to 1300:1, from 150:1 to 1400:1, from 300:1 to 450:1, from 300:1 to 600:1, from 300:1 to 750:1, from 300:1 to 900:1, from 300:1 to 1000:1, from 300:1 to 1100:1, from 300:1 to 1200:1, from 300:1 to 1300:1, from 300:1 to 1400:1, from 300:1 to 1500:1, from 450:1 to 600:1, from 450:1 to 750:1, from 450:1 to 900:1, from 450:1 to 1000:1, from 450:1 to 1100:1, from 450:1 to 1200:1, from 450:1 to 1300:1, from 450:1 to 1400:1, from 450:1 to 1500:1, from 600:1 to 750:1, from 600:1 to 900:1, from 600:1 to 1000:1, from 600:1 to 1100:1, from 600:1 to 1200:1, from 600:1 to 1300:1, from 600:1 to 1400:1, from 600:1 to 1500:1, from 750:1 to 900:1, from 750:1 to 1000:1, from 750:1 to 1100:1, from 750:1 to 1200:1, from 750:1 to 1300:1, from 750:1 to 1400:1, from 750:1 to 1500:1, from 900:1 to 1000:1, from 900:1 to 1100:1, from 900:1 to 1200:1, from 900:1 to 1300:1, from 900:1 to 1400:1, from 900:1 to 1500:1, from 1000:1 to 1100:1, from 1000:1 to 1200:1, from 1000:1 to 1300:1, from 1000:1 to 1400:1, from 1000:1 to 1500:1, from 1100:1 to 1200:1, from 1100:1 to 1300:1, from 1100:1 to 1400:1, from 1100:1 to 1500:1, from 1200:1 to 1300:1, from 1200:1 to 1400:1, from 1200:1 to 1500:1, from 1300:1 to 1400:1, from 1300:1 to 1500:1, or from 1400:1 to 1500:1.

[0047] According to one or more embodiments, a ratio of the liquid feed 103 (gallons per minute) to the pump suction rate (gallons per minute) may be from 5:1 to 200:1. For example, the ratio of the liquid feed 103 to the pump suction rate may be from 5:1 to 10:1, from 5:1 to 20:1, from 5:1 to 30:1, from 5:1 to 40:1, from 5:1 to 50:1, from 5:1 to 60:1, from 5:1 to 70:1, from 5:1 to 80:1, from 5:1 to 90:1, from 5:1 to 100:1, from 5:1 to 125:1, from 5:1 to 150:1, from 5:1 to 175:1, from 10:1 to 20:1, from 10:1 to 30:1, from 10:1 to 40:1, from 10:1 to 50:1, from 10:1 to 60:1, from 10:1 to 70:1, from 10:1 to 80:1, from 10:1 to 90:1, from 10:1 to 100:1, from 10:1 to 125:1, from 10:1 to 150:1, from 10:1 to 175:1, from 10:1 to 200:1, from 20:1 to 30:1, from 20:1 to 40:1, from 20:1 to 50:1, from 20:1 to 60:1, from 20:1 to 70:1, from 20:1 to 80:1, from 20:1 to 90:1, from 20:1 to 100:1, from 20:1 to 125:1, from 20:1 to 150:1, from 20:1 to 175:1, from 20:1 to 200:1, from 30:1 to 40:1, from 30:1 to 50:1, from 30:1 to 60:1, from 30:1 to 70:1, from 30:1 to 80:1, from 30:1 to 90:1, from 30:1 to 100:1, from 30:1 to 125:1, from 30:1 to 150:1, from 30:1 to 175:1, from 30:1 to 200:1, from 40:1 to 50:1, from 40:1 to 60:1, from 40:1 to 70:1, from 40:1 to 80:1, from 40:1 to 90:1, from 40:1 to 100:1, from 40:1 to 125:1, from 40:1 to 150:1, from 40:1 to 175:1, from 40:1 to 200:1, from 50:1 to 60:1, from 50:1 to 70:1, from 50:1 to 80:1, from 50:1 to 90:1, from 50:1 to 100:1, from 50:1 to 125:1, from 50:1 to 150:1, from 50:1 to 175:1, from 50:1 to 200:1, from 60:1 to 70:1, from 60:1 to 80:1, from 60:1 to 90:1, from 60:1 to 100:1, from 60:1 to 125:1, from 60:1 to 150:1, from 60:1 to 175:1, from 60:1 to 200:1, from 70:1 to 80:1, from 70:1 to 90:1, from 70:1 to 100:1, from 70:1 to 125:1, from 70:1 to 150:1, from 70:1 to 175:1, from 70:1 to 200:1, from 80:1 to 90:1, from 80:1 to 100:1, from 80:1 to 125:1, from 80:1 to 150:1, from 80:1 to 175:1, from 80:1 to 200:1, from 90:1 to 100:1, from 90:1 to 125:1, from 90:1 to 150:1, from 90:1 to 175:1, from 90:1 to 200:1, from 100:1 to 125:1, from 100:1 to 150:1, from 100:1 to 175:1, from 100:1 to 200:1, from 125:1 to 150:1, from 125:1 to 175:1, from 125:1 to 200:1, from 150:1 to 175:1, from 150:1 to 200:1, or from 175:1 to 200:1.

[0048] In some embodiments, the system 100 may comprise various process controls. For example, the process controls may determine when the sparger 104 is to be activated or when the particulate removal system is to be activated. As the sparger 104 and particulate removal system may operate intermittently in some embodiments, the process controls may determine when the sparger 104 or the particulate removal system is to be activated. A pressure sensor may be adjacent to or coupled to the vertical filtration screen 101, such that the pressure sensor is operable to detect a pressure drop across the vertical filtration screen 101. As there will be some pressure drop across the vertical filtration screen 101 due to the presence of the vertical filtration screen 101 itself, the pressure sensor may be configured to account for the inherent pressure drop due to the vertical filtration screen 101 itself. However, such a pressure drop beyond the pressure drop associated with the vertical filtration screen 101 itself may be evidence that the vertical filtration screen 101 may be obstructed by particulates. A processor may be in communication with the pressure sensor and the sparger 104. When a pressure drop above a predetermined pressure drop threshold is determined by the pressure sensor, the processor may activate the sparger 104. The sparger 104 may then direct a bubble curtain towards the vertical filtration screen 101 such that the particulates obstructing the vertical filtration screen 101 may be scrubbed from the vertical filtration screen 101. [0049] In some embodiments, a set of level sensors may be operable to may determine when the sparger 104 is to be activated or when the particulate removal system is to be activated. One level sensor may be positioned upstream of the vertical filtration screen 101 and a second level sensor may be positioned downstream of the vertical filtration screen 101. If a sufficient discrepancy is detected by the level sensors, such that the level of the liquid feed 103 upstream of the vertical filtration screen 101 is a certain amount higher (with respect to the vertical filtration screen 101) than the liquid feed 103 downstream of the vertical filtration screen 101, the sparger 104, the particulate removal system, or both may be activated. A discrepancy in the level of the liquid feed 103 upstream and downstream of the vertical filtration screen 101 may be evidence that the vertical filtration screen 101 may be obstructed by particulates. As with the pressure sensor discussed above, a processor may be in communication with the level sensors and the sparger 104. When a discrepancy in the level of the liquid feed 103 upstream and downstream of the vertical filtration screen 101 above a predetermined threshold is determined by the level sensors, the processor may activate the sparger 104. The sparger 104 may then direct a bubble curtain towards the vertical filtration screen 101 such that the particulates obstructing the vertical filtration screen 101 may be scrubbed from the vertical filtration screen 101.

[0050] In some embodiments, a sensor or detector may be operable to determine when floating or sinking particulates have accumulated in the liquid feed 103 upstream of the vertical filtration screen 101. The sensor or detector located in the liquid feed 103 may be in communication with a processor in communication with the pump 105. Upon sensing or detecting an amount of particulates above an upper threshold of acceptable particulates upstream of the vertical filtration screen 101, the processor may be operable to trigger the activation of the particulate separation system, such that the pump 105 begins to remove a particulate containing stream 115 from the liquid feed 103 and begins to treat the particulate containing stream 115 it in the separation device 106.

[0051] In some embodiments, the pump 105 and the particulate removal system may be configured to operate in tandem, such that when either the pressure drop sensor or the particulate accumulation sensor senses a pressure drop above the pressure drop threshold or a particulate accumulation above the particulate accumulation threshold, respectively, both the sparger 104 and the pump 105 are activated no matter which sensor was triggered. Alternative and additional process controls to those described herein will be appreciated by those skilled in the art. EXAMPLES

[0052] Embodiments will be further clarified by the following examples.

[0053] Example 1: Effect of Bubble Curtain

[0054] In Example 1 , both polyethylene pellets (having a particle size of 2 to 5 millimeter) and polyethylene powder (having a particle size of 45 to 1,000 micrometer) were added to water. A vertical filtration screen of No. 18 mesh comprising filtration openings with a size of 1 millimeter was fixed in a vertical position. The water flow rate (including the polyethylene pellets and the polyethylene powder) was 12.5 gpm. A sparger comprising a sparger hole size of Vi₆ inch, a distance of V2 inch between sparger holes, and an internal diameter of ^l inch was installed parallel and upstream of the vertical filtration screen. However, in the first trial, the sparger was not used to form a bubble curtain. In the second trial, the sparger was used to form a bubble curtain. In the second trial, the sparger was supplied with an air source comprising a pressure of 80 psi and an air flow rate of 1 scfm. The two trials and their respective results are summarized in Table 1.

Table 1

[0055] Thus, as can be seen from Table 1, no polyethylene pellets in the liquid feed passed through the vertical filtration screen. As the vertical filtration screen comprised a filtration opening size of 1 millimeter, it may be expected that the polyethylene pellets would not pass through the vertical filtration screen. Additionally, both trials demonstrate that some polyethylene powder passed through the vertical filtration screen, but the trial utilizing a bubble curtain demonstrates a great reduction in the amount of polyethylene powders to pass through the vertical filtration screen. This demonstrates an increased effectiveness at removing particulates when operating a vertical filtration screen in conjunction with a bubble curtain.

[0056] Example 2: Effect of Smaller Filtration Opening [0057] In Example 2, Example 1 was repeated except that the vertical filtration screen was replaced with a vertical filtration screen of No. 325 mesh comprising filtration openings with an opening size of 45 micrometer. In Example 2, whether the sparger was used to form the bubble curtain or not, no polyethylene powder passed through the vertical filtration screen. Therefore, the separation efficiency of both the polyethylene pellets and the polyethylene powder was 100%. When the sparger was not used to form the bubble curtain, the polyethylene powder began fouling the vertical filtration screen within twenty minutes. However, when the sparger was used to form the bubble curtain, the bubble curtain prevented floating powders from contacting the vertical filtration screen. When fouling had already occurred on the vertical filtration screen, the bubble curtain scrubbed the polyethylene powders from the vertical filtration screen.

[0058] Example 3: Effect of Increased Liquid Feed

[0059] In Example 3, Example 2 was scaled up with an increase in the liquid feed. In Example 3, the water flow rate (including the polyethylene pellets and the polyethylene powder) was roughly 1,300 gpm. A vertical filtration screen of No. 325 mesh comprising filtration openings with an opening size of 45 micrometer. Finally, the sparger comprised a sparger hole size of Vi₆ inch, a distance of V2 inch between sparger holes, and an internal diameter of 2 inch. The sparger was supplied with an air source comprising a pressure of 23 psi. No visual observation of solids was observed behind the screen.

[0060] In Example 3, when the sparger was not used to form the bubble curtain, fouling was seen on a portion of the screen after thirty minutes. However, after operating the sparger for thirty minutes, the polyethylene particulates were removed the vertical filtration screen.

[0061] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.

Claims

1. A system for removing particulates comprising: at least one vertical filtration screen comprising a plurality of filtration openings configured to sieve particulates greater in size than the plurality of filtration openings from a liquid feed; at least one sparger disposed parallel and upstream of the at least one vertical filtration screen, the at least one sparger comprising an elongated body and a plurality of sparger openings spaced along a length of the elongated body, wherein the sparger is in fluid communication with an air source which is operable to pass an air feed out of the plurality of sparger openings to create a bubble curtain adjacent to the at least one vertical filtration screen; a particulate removal system comprising at least one pump, at least one separation device, a removal pipe fluidly connecting the pump and the separation device, and a return pipe fluidly connected to the separation device, wherein: the pump is disposed upstream of the at least one vertical screen and is configured to transfer a particulate containing stream comprising sieved particulates removed from the at least one vertical filtration screen and the bubble curtain; and the separation device is configured to remove particulates from the particulate containing stream.

2. The system of claim 1, wherein the return pipe is configured to transfer the filtered stream to be combined with liquid feed.

3. The system of either of claims 1 or 2, wherein the separation device comprises at least one separation screen.

4. The system of any one of the preceding claims, wherein the pump is a submersible pump.

5. The system of any one of the preceding claims, wherein the system comprises two or more vertical filtration screens.

6. The system of claim 5, wherein the system comprises two vertical filtration screens comprising filtration openings of differing opening sizes.

7. The system of any one of the preceding claims, wherein the sparger extends the length of the at least one vertical filtration screen.

8. The system of any one of the preceding claims, wherein the filtration openings have an opening size of 20 micrometers to 10 millimeters.

9. A method of removing particulates comprising: passing a liquid feed containing particulates through a vertical filtration screen, the vertical filtration screen comprising a plurality of filtration openings that sieves particulates from the liquid feed; directing an air feed through a plurality of sparger holes from a sparger to form a bubble curtain across the vertical filtration screen wherein the bubble curtain concentrates the filtered particulates at a pump; producing a filtered stream by pumping a particulate containing stream to a separation device to separate out the filtered particulates; and recycling the filtered stream.

10. The method of claim 9, further comprising combining the filtered stream with the liquid feed.

11. The method of either of claims 9 or 10, further comprising discarding the filtered particulates.

12. The method of any of claims 9 through 11, further comprising passing the liquid feed through a second vertical filtration screen comprising a plurality of filtration openings that sieves particulates from the liquid feed.

13. The method of any of claims 9 through 12, wherein the separation device comprises at least one screen.

14. The method of claim 13, wherein the separation device comprises a shaking screen separator.

15. The method of any of claims 9 through 13, wherein the ratio of the liquid feed (gallons per minute) to the air feed (standard cubic feet per minute) is from 150:1 to 1500:1.