Patent Application
20240375123
Embodiments of the present invention pertain to improvements to gravity separation and flotation machines, in particular, “rotorless” gravity- and fluidized bed-assisted flotation apparatus. In particular, embodiments of the present invention relate to a unique flexible perforated membrane sparger for optimizing bubble size distributions within a fluidized bed and/or facilitating periodic sparger purging. Embodiments may further include a method involving the dual-shearing of aerated fluidization fluids.
Reference to background art herein is not to be construed as an admission that such art constitutes common general knowledge in the arts.
In many industrial processes, fluidized beds are used to suspend solids and perform various separations within equipment. An example of such device can be found in U.S. Pat. No. 6,814,241 B1. Another example can be found in the FLSmidth® REFLUX® classifier, a specialized gravity-assisted separation device.
Turning now to
Solids within the incoming slurry 13 are separated by gravity, wherein finer or less-dense particles are discharged at an upper portion of the device 1 by passing over a weir 16 (as overflow 15), and entering into a collection launder 17. Coarser or denser particles fail to move upward within the separation chamber 7 and end up being discharged through a lower outlet 9 passing through a central opening in the fluidization fluid panel 11. The coarser or denser particles pass through/by the fluidization fluid distribution chamber 8 and exit the bottom of the device 1 (as underflow 14).
An upper separation chamber 6 may be provided between the weir 16 and the separation chamber 7, and this upper separation chamber 6 may comprise a number of lamellae or spaced (e.g., parallel) inclined plates 5 to improve separations. By adjusting flows of incoming slurry 13 and fluidization fluid 12, separations can be optimized for a particular process.
Similar units may be designed for use for flotation, in addition to, or in lieu of classification. An example can be seen in WO 2020152651 A1, where the incoming fluidization fluid 12 is aerated within the fluidization fluid distribution chamber 8 prior to passing through the fluidization fluid panel 11 and into the separation chamber 7. Bubbles within the separation chamber 7 combine with hydrophobic particles and move upwardly where they eventually make their way to the collection launder 17 as froth overflow 15. Hydrophilic particles fail to bind with the bubbles within the separation chamber 7 and eventually make their way to the lower outlet 9 as underflow 14.
A problem with such devices, is that the openings 10 in the fluidization fluid panel 11 (e.g., orifices extending through panel 11), can clog and/or may not adequately provide controlled bubble size distributions, uniform bubbly zones, or fine bubble size adjustments within the separation chamber 7. Openings 10 comprising a large number of nozzles or spargers provided to the fluidization fluid panel 11 can significantly increase manufacturing costs and total time to fabricate and service. Nozzles and spargers provided to fluidization fluid panel 11 can also clog over time and may be difficult to purge without removal.
Embodiments of the present invention aim to improve upon existing gravity separation apparatus and fluidized bed-assisted (i.e., “rotorless”) flotation machines by incorporating low-cost flexible perforated membrane structures which synergistically work together to provide a more homogeneous bubble size distribution, more uniform introductions of aerated fluidization fluid, and improved recoveries. By virtue of their ability to flex, openings may be configured to temporarily elastically expand, thus, facilitating the removal of particle occlusions.
It is an aim that embodiments of the invention provide an improved gravity separation, gravity-assisted classification, or gravity-assisted flotation apparatus which overcomes or ameliorates one or more of the disadvantages or problems described above, or, which at least provides a useful alternative to related conventional apparatus.
An aim of some embodiments of the invention may include providing an improved separator device 100 which exhibits much finer bubble sizes within its separation chamber 107 to improve efficiency, recovery, and/or operational performance of the separator device 100, without limitation.
Another aim of some embodiments of the invention may include providing an improved separator device 100 which is less prone to plugging of openings 11 used to distribute aerated fluidization fluid to a separation chamber 107, without limitation.
Another aim of some embodiments of the invention may include providing an improved separator device 100 having aerated fluidization fluid distribution means for providing aerated fluidization fluid to its separation chamber 107 which comprises a flexible perforated membrane element configured to expand to clear obstructions of openings or perforations therein, without limitation.
Another aim of some embodiments of the invention may include providing an improved separator device 100 which is capable of double-shearing an aerated fluidization fluid prior to its introduction into its separation chamber 107, in order to provide controlled smaller bubble sizes and tighter bubble size distributions without limitation.
A further aim of some embodiments of the invention may include providing an improved separator device 100 which provides a more even distribution of gas/liquid mixtures proximate a lower and/or central region of its separation chamber 107, without limitation.
Yet another aim of some embodiments of the invention may include providing an improved separator device 100 which allows periodic purging and/or cleaning of clogged pores by virtue of the provision of a flexible perforated membrane sparger; wherein periodically, the pressure of aerated fluidization fluid behind the flexible perforated membrane can be temporarily increased to cause temporary elastic deformation, flexing, and/or expansion of a surface area of the flexible membrane, thereby temporarily increasing a size or minimum width of perforations or openings extending through the flexible membrane. As such, aerated fluidization fluid under increased pressure can pass through the temporarily-increased sized perforations or openings to help dislodge particles from incoming slurry 13 which may have occluded the perforations or openings during operation of the separator device 100.
A further aim of some embodiments of the invention may include providing an improved separator device 100 that provides aerated fluidization fluid to its separation chamber 7, which is easier and cheaper to manufacture and service, without limitation.
It should be understood that not every embodiment may be configured to obtain each and every one of the abovementioned objects. However, specific embodiments may demonstrate the ability to achieve or satisfy at least one or more of the abovementioned goals.
Other preferred objects of the present invention will become apparent from the following description.
According to embodiments of the invention, a separator device 100 is disclosed. The separator device 100 may be utilized for gravity separation, classification of particles by size and/or density, and/or segregation of particles by hydrophobicity (e.g., flotation separation or coarse particle flotation). The separator device 100 may be fed with an incoming slurry 13 containing the particles to be separated (e.g., by virtue of gravity-assisted classification or flotation by minerology).
A separator device (100) according to embodiments may comprise a separation chamber (107). The separation chamber (107) may be defined at its lower end by a fluidization fluid panel (111). The separation chamber (107) may be further defined (i.e., bounded) on its sides by a tank wall (103).
A lower outlet (109) may be provided at a lower end of the separator device (100). The lower outlet (109) may extend downwardly through a central region of the lower fluidization fluid panel (111).
A launder (117) may be provided at an upper end of the separator device (100). The separator device (100) may further comprise a slurry inlet (102) for receiving incoming slurry (113) into the separation chamber (107).
The separator device (100) may be characterized in that means (122) for supplying pre-sheared aerated fluidization fluid may be provided above the fluidization fluid panel (111). The means (122) for supplying pre-sheared aerated fluidization fluid may include a sparger (119), in particular, a sparger comprising a flexible perforated membrane structure.
In some embodiments, the sparger (119) may be configured as one of the group consisting of: a straight tube, a curved tube, a coil, a disc, a puck, a panel, and a plate, without limitation.
In some embodiments, the sparger (119) may comprise two ends. In some embodiments, the sparger (119) may be fed at one of its ends (e.g., a first proximal end) with the pre-sheared aerated fluidization fluid, without limitation. In some embodiments, the sparger (119) may be fed at both of its ends (e.g., a first proximal end and a second distal end) with the pre-sheared aerated fluidization fluid, without limitation.
In some embodiments, the separator device (100) may comprise a plurality of the aforementioned sparger (119), without limitation. In some embodiments, each of the plurality of sparger (119) may be nested and/or packed together, without limitation.
In some embodiments, each of the plurality of sparger (119) may be of different sizes or shapes, without limitation. In some embodiments, each of the plurality of sparger (119) may be oriented differently in space with respect to one or more components of the separator (100) device, without limitation.
In some embodiments, the sparger (119) (or plurality thereof) may be horizontally-arranged, without limitation. In some embodiments, the sparger (119) (or plurality thereof) may be inclined so as to follow an angle of the fluidization fluid panel (111), without limitation.
In some embodiments, the pre-sheared aerated fluidization fluid may be produced by combining fluidization fluid (112) with a gas (118) and then subsequently passing the mixture thereof through a shearing device (126) downstream of where the fluidization fluid (112) and gas (118) are combined.
In some embodiments, the shearing device (126) may be selected from the group consisting of: a static inline mixer, a cavitation tube, a cavitation nozzle, and a chaos mixer, without limitation.
A sparger (119) for a separator device (100) according to the above description(s) may be provided, advertised, offered for sale, sold, fabricated, imported, exported, and/or shipped, without limitation.
A method for separating particles within an incoming slurry (113) is further disclosed. As suggested by
In some embodiments, the method may comprise the step of intermittently or periodically boosting the pressure of the first sheared aerated fluid provided to the sparger (119). This step may be advantageously utilized to periodically purge blockages or occlusions within openings or perforations of the flexible perforated membrane structures, without limitation. Flowrate of the first sheared aerated fluid provided to the sparger(s) (119) may also be temporarily increased to provide a purging cycle functionality, without limitation. In some embodiments, the method may comprise expanding or flexing portions of the flexible perforated membrane by virtue of boosting the pressure and/or flowrate to the spargers (119), without limitation.
The method may include the step of allowing the openings or perforations extending through the flexible perforated membrane of the sparger (119) to temporarily expand (i.e., by elastic deformation), thus allowing the first sheared aerated fluid provided to the sparger (119) to pass therethrough at an elevated velocity and/or energy, without limitation. The method may include the step of clearing obstructions or dislodging one or more particles from the openings or perforations extending through the flexible perforated membrane of the sparger (119) by virtue of the elevated velocity and/or energy, and/or by virtue of expansion of the openings or perforations extending through the flexible perforated membrane of the sparger (119). After purging, the pressure (and/or flowrate) of the first sheared aerated fluid provided to the sparger (119) may be reduced to normal operating conditions, wherein the flexible perforated membrane structure returns to a normal configuration having smaller openings and/or perforations therein.
Further features and advantages of the present invention will become apparent from the following detailed description.
By way of example only, preferred embodiments of the invention will be described more fully hereinafter with reference to the accompanying figures. It will be appreciated from the drawings that some of
A separator device 100 may comprise a tank wall 103 defining a (main) separation chamber 107. A slurry inlet 102 configured to introduce incoming slurry 113 to the separation chamber 107 may extend from an upper portion of the tank wall 103. In some embodiments, the tank wall 103 may be defined from one or more portions of an upper segment 133, a middle segment 134, and a lower segment 135, without limitation. The slurry inlet 102 may fluidly communicate with the separation chamber 107.
The bottom of the separation chamber 107 may be delineated by a fluidization fluid panel 111, which may be optionally perforated, should an optional fluidization fluid distribution chamber 108 be provided to the separator device 100 below the separation chamber 107. The central region of the fluidization fluid panel 111 may give way to a centrally located lower outlet 109 which is configured to allow solids to pass through the fluidization fluid panel 111 and remove them as underflow 114 from the separator device 100 as depicted.
If a fluidization fluid distribution chamber 108 is provided to the separator device 100 (e.g., below separation chamber 107), a fluidization fluid inlet 104 may be provided to deliver incoming fluidization fluid 112 with optional air or gas 118 therein. Moreover, the fluidization fluid panel 111 may comprise a number of optional openings 110 (e.g., perforations, slots, orifices, or nozzles) therein to convey fluidization fluid 112 and optional air or gas 118 through the fluidization fluid panel 111 and into the separation chamber 107, without limitation.
An upper separation chamber 106 may be provided above the separation chamber 107. As shown in
According to preferred embodiments, a flexible perforated membrane sparger 119 comprising a flexible perforated membrane structure may be provided. One or more flexible perforated membrane spargers 119 may be provided within the separation chamber 107, above the fluidization fluid panel 111, in order to economically distribute fine bubbles within the separation chamber 107 during operation. Means 122 for supplying pre-sheared aerated fluidization fluid to the flexible perforated membrane sparger 119 may be provided, such that during operation, the flexible perforated membrane sparger 119 may receive pre-sheared aerated fluidization fluid under pressure and the same may pass through the openings or perforations within the flexible perforated membrane structure of the sparger 119, thus twice-shearing the received aerated fluidization fluid before it enters into the separation chamber 107.
Said differently, a first shearing of the aerated fluidization fluid mixture of fluidization fluid 112 and air or gas 118 may be performed by the shearing device 126, and a second shearing of the first-sheared mixture leaving the shearing device 126 may be performed such that the first-sheared mixture is sheared a second time as it passes through the openings or perforations within the flexible perforated membrane structure of the sparger 119.
Air or gas 118 may be pre-mixed with incoming fluidization fluid 112 and then be pre-sheared using a shearing device 126 (e.g., an inline static mixer, a cavitation tube, a cavitation nozzle, a chaos mixer, or the like, without limitation). As will be appreciated from
A sparger feed device 130 may be provided with a first inlet 131 for receiving a flow of fluidization fluid 112, and a second inlet 132 for receiving a flow of air or gas 118. The fluid 112 and air or gas 118 may be combined within the device 130 and passed through an internal shear device 126. A portion of the sparger feed device 130 may comprise connecting means 128, such as a threaded outer diameter or mounting flange having bolt holes for connecting the sparger feed device 130 to the tank wall 103 of the separator device 100. The sparger feed device 130 is preferably provided adjacent a lower outer region of the separation chamber 107. Downstream of the internal shearing device 126 may be a main feed line 120 that delivers pre-sheared aerated fluidization fluid to a flexible perforated membrane sparger 119 provided in the form of an extractable straight tube. The tube may comprise a free end that remains cantilevered and suspended within a region of the separation chamber 107. The sparger feed device 130 may be removed from the tank wall 103 by disengaging the connecting means 128 from the tank wall 103 and laterally extracting both the sparger feed device 130 and flexible perforated membrane sparger 119 from the separator device 107 together, without limitation.
Pre-sheared aerated fluidization fluid may pass from the shearing device 126 to a main feed line 120. The main feed line 120 may, in some embodiments, serve to directly feed a flexible perforated membrane sparger 119 located within the separation chamber 107. In some embodiments, the main feed line 120 may serve to feed a manifold 121 which indirectly feeds a number of flexible perforated membrane spargers 119. For example, as depicted in
Pre-sheared aerated fluidization fluid delivered to a flexible perforated membrane sparger 119 may be optimized by providing a flow indicative transmitter (FIT) 123 and a control valve 124 at each respective source of incoming fluidization fluid 112 and incoming air or gas 118, as depicted. The flow indicative transmitters 123 can measure respective amounts of incoming fluidization fluid 112 and air or gas 118, and may be used to monitor and/or control ratios of each prior to mixing in the shearing device 126. For example, a flow indicative transmitter 123 may send one or more control signals 125, to a control valve 124 to independently restrict or increase flow of fluidization fluid 112 or air/gas 118 to shearing device 126. In this regard, a ratio of fluidization fluid 112 and air or gas 118 can be controlled or adjusted, as needed, prior to entering the shearing device 126.
Embodiments of the unique flexible perforated membrane spargers 119 disclosed herein are preferably configured to discharge microbubbles 129 within the separator chamber 107. By virtue of providing twice-sheared aerated fluidization fluid, bubble sizes may be optimized for separations and may demonstrate improved performance in certain separations such as classification by mineralogy by flotation.
At any point in time, should openings or perforations within flexible perforated membrane structures of one or more of the spargers 119 become occluded, blocked, or clogged by particles within the separation chamber 107, an intermittent or periodic purge cycle may take place wherein control valves 124 may be opened to allow a greater amount of pre-sheared aerated fluidization fluid therein. Alternatively, a temporary boost in pressure of the incoming fluidization fluid 112 or gas 118 sources may be initiated (manually or via a control system) to the holding tanks thereof.
Blockages of openings or perforations within flexible perforated membrane structures of one or more of the spargers 119 may be determined by continuously or periodically monitoring outflows 14, 15 of the separator device 100 and/or by continuously or periodically monitoring flowrates using the flow indicative transmitters 123. In cases where there is little or no change in outflows 14, 15, or a reduction in outflow 14, 15 with increasingly greater required inflows of fluidization fluid 112 or gas 118, a blockage of flexible perforated membrane structure may be inferred, and a boost overpressure purging cycle may be warranted.
Since the unique spargers 119 described herein (and depicted in the accompanying drawings) preferably incorporate a flexible perforated membrane structure, any occlusions, blockages, or clogging of openings or perforations in the flexible perforated membrane structures of the spargers 119 may be remedied by supplying an intermittent temporary increase in pressure or flow of pre-sheared aerated fluidization fluid. By increasing pressure or flow to each sparger 119, the flexible perforated membrane structure may stretch, expand, increase in surface area, or elastically deform, such that its openings or perforations may temporarily increase in size and allow a pre-sheared aerated fluidization fluid at increased velocities through them to encourage removal of particles that might be stuck within the openings or perforations.
Turning now to
One or a plurality of the aeration inserts 136 depicted in
The separator device 100 system may further comprise one or more “backup”, “standby” or “replacement” aeration inserts 136, which may be reserved for standby use, future installation, and/or spare parts for servicing a middle segment 134 of the separator device 100.
If/when the separator device 100 of the system experiences fouling of flexible perforated membrane spargers 119 of one or more of the installed aeration inserts 136, the middle segment 134 may be disassembled/detached from the upper 133 and lower 135 sections (e.g., by unbolting at flanges 138), and may be removed from the separator device 100. The one or more backup, standby, or replacement aeration inserts 136 of the system may then be installed and secured between the upper 133 and lower 135 segments (e.g., by tightening bolts 137 at respective flanges 138), and serve as a new middle segment 134 of the separator device 100. In this regard, removed aeration section(s) 136 may be serviced, cleaned, and/or have their flexible perforated membrane spargers 119 removed and replaced with new flexible perforated membrane spargers 119, while the separator device 100 operates. Thus, a separator device 100 system may be configured to achieve reduced separator device 100 downtime and minimize operating expenditures (OPEX) associated with extended periods of non-operation. By providing one or more backup, standby, or replacement aeration inserts 136, the middle segment 134 of the separator device 100 may be readily swapped in and out of the separator device 100 in a quick and convenient manner, and enable the separator device 100 to resume operation in a short amount of time.
As can be seen from
In the particular embodiment shown, the flexible perforated membrane sparger 119 may comprise an elongated tubular flexible perforated membrane structure which forms a chamber or cavity designed to receive gaseous liquid. The gaseous liquid may be formed by mixing a liquid fluid 112 with a gas fluid 118 (e.g., in any of the manners suggested by
The tubular flexible perforated membrane structure may comprise a receiving portion 141 for accepting a first threaded end 142 of a pipe connector 143, without limitation. The receiving portion 141 may comprise a threaded surface for threaded engagement with the first threaded end 142 of the pipe connector 143, without limitation. The threaded engagement may comprise a conventional NPT-style fitting, without limitation.
A second threaded end 146 of the pipe connector 143 may threadedly engage a tubular body portion 145a of an endcap 145. The endcap 145 may comprise a flange portion 145b integrally-connected with and/or supporting the tubular body portion 145a as depicted. An inlet flange 140 comprising a tubular portion 140a and a flange portion 140b may extend from the annular body 139 of the aeration insert 136. The tubular portion 140a may be permanently or removably affixed to the body 139. For example, the tubular portion 140a of the inlet flange 140 may be welded or screwed into an opening 149 of the annular body 139 (this is most clearly seen in
The flexible perforated membrane sparger 119 may be installed within the aeration insert 136 by inserting it through the inlet flange 145 and opening 149 of the annular body 139. An optional gasket 144 may be placed over the flange portion 140b of the inlet flange prior to insertion of the sparger 119. The flange portion 145b of the endcap 145 may then be secured to the flange portion 140b of the inlet flange 140 by aligning one or more respective through openings 145d extending through the flange portions 140b, 145d, and inserting fasteners through the one or more through openings 145d. The fasteners (not shown for clarity) are preferably bolts and may be secured in traditional fashion, for example, by threading a nut to a threaded distal end of each bolt. Washers (including the locking type) may be used with the fasteners, without limitation. Fasteners comprising self-locking nuts may also be utilized, without limitation.
The endcap 145 may comprise a gaseous liquid inlet hose connecting portion 145c as shown. The gaseous liquid inlet hose connecting portion 145c may comprise a threaded feature or quick-connect hydraulic coupling, without limitation. The gaseous liquid inlet hose connecting portion 145c may be defined in the flange portion 145b of the endcap 145, or may be formed adjacent an end of the tubular body portion 145a. As depicted, the gaseous liquid inlet hose connecting portion 145c may be defined within the tubular body portion 145a of the endcap, although it may be defined on external surfaces thereof. The tubular body portion 145a may extend beyond the flange portion 145b of the endcap 145 as shown, to provide a portion of a hydraulic connector and/or hydraulic connection surface, without limitation.
The separator device 100 and/or flexible perforated membrane sparger structures 119 described and illustrated herein are provided merely as examples to which the invention of the claims may be applied. The specification does not suggest that the claims are somehow limited to or apply only to the particular embodiments shown and described herein.
Where used herein, the terms “upper segment”, “middle segment”, and “lower segment” may be used interchangeably with the terms “upper section”, “middle section”, and “lower section”, respectively, without limitation. It should be understood that where used herein, the middle segment 134 may be synonymous or used interchangeably with “second middle section”, “second middle segment”, or “aeration insert 136”. The term “aeration insert” has been chosen by the applicant, but it should be understood that this term may be used interchangeably with other terms such as “aeration device”, “aeration segment”, “aeration section”, “aeration insert”, “aeration disc”, “aeration ring”, “aeration portion of the separator device”, or the like, without limitation. It is believed that those skilled in the art would appreciate and anticipate other terms and lexicography could adequately represent the disclosed features.
Where used herein, the terms “gaseous liquid” and “second sheared aerated fluid” may be used interchangeably, without limitation. It should be understood that the spargers 119 described and depicted in
Where used herein, the term “perforated” or “perforations” may be broadly construed as a membrane having passages in which gas and/or liquid may pass. Thus, a “perforated” membrane, where used herein, may include a sheet (preferably flexible) with one or more slits having substantially zero width, one or more slots with minimal discernible width, one or more pin holes or pin pricks of substantially zero diameter, one or more pin holes or pin pricks with minimal discernible width, small substantially symmetrical openings (e.g., orifices), one or more small elongated openings, or the like, without limitation. For example, in some preferred embodiments, ˜1 mm spaced slits (±0.5 mm) may be applied to a membrane in a preferably uniformly-distributed pattern, with the slits being formed with substantially no discernible width when the membrane is in a relaxed, unstressed, and/or non-flexed state. In some preferred embodiments, approximately 100 of such slits or “perforations” may be provided to the membrane per square inch of membrane, without limitation. It is anticipated that a greater or lesser number of perforations may be provided (e.g., 1 perforation per square inch to as much as 150 perforations per square inch, such as 50-150 perforations per square inch). The material mechanical properties of the membrane (e.g., elastic modulus, elasticity, etc.) may ultimately determine the maximum number of perforations that may be practically provided per square inch of membrane without causing rupture of the membrane due to tearing adjacent the perforations.
In some embodiments, the perforations in the membrane may comprise a combination of one or more of the following, without limitation: slits, pin holes, pin pricks, symmetrical openings, elongated openings. The perforations may be provided in any practical variation, number, combination, or pattern, but are preferably spaced and/or staggered with respect to one another and uniformly-distributed across surface areas of the membrane. In some embodiments, the one or more slits, pin holes, pin pricks, symmetrical openings, and/or elongated openings may appear to be closed in an unstressed membrane state or otherwise form a normally-closed aperture (e.g., when the sparger is in an unpressurized state); wherein upon an application of pressure or fluid flow force to the sparger, the same one or more perforations may open slightly to define an orifice capable of allowing a passage or flow of a fluid such as gas and/or liquid through the membrane, without limitation. In this regard, a flexible perforated membrane sparger as described herein may be configured for (or inherently comprise means for) “backflow prevention”, wherein fluids are able to pass from within the sparger through the perforated flexible membrane structure (via the perforations) and finally to regions surrounding external surface portions the sparger, but wherein solids may not necessarily be able to pass thereinto if the sparger is depressurized or membrane relaxed. By minimizing the open orifice area for the one or more perforations, backflow of solids into the flexible perforated membrane sparger is deterred or substantially inhibited.
To test backflow prevention capability, a flexible perforated membrane sparger of the type described was placed into a closed pipe (chamber) with the sparger inlet open to atmosphere (e.g., thus the inner portions of the flexible perforated membrane sparger were maintained at “atmospheric pressure” during all portions of the test). Slurry was then fed into the closed pipe (chamber) surrounding the flexible perforated membrane sparger in order to surround and pressurize the exterior surfaces of the sparger with the slurry. Pressure in the pipe (chamber) externally acting on surface portions of the sparger was started at 20 psig and then increased by 5 psig for successive intervals. The closed pipe (chamber) was held for 5 minutes at each successive interval of increased slurry pressure. Due to the nature and configuration of the small perforations (i.e., closed ˜1 mm slits), water from the slurry only began to leak back through the flexible perforated membrane and into the sparger body via the perforations at a significant 60 psig pressure level. However, no discernible solids were found to be present within the sparger body at this pressure. The test ceased after reaching a maximum of 60 psig in the pipe (chamber). Accordingly, the inventors have concluded that in the event internal sparger feed pressure drops substantially during operation within a flotation cell (e.g., during interruptions, pump failure, or maintenance cycles), large heads within the cell would be required to begin fouling the internals of the flexible perforated membrane spargers described herein. Thus, the design and configuration of the flexible perforated membrane structures disclosed may demonstrate suitable backflow prevention performance characteristics.
In some embodiments, the one or more slits, pin holes, pin pricks, symmetrical openings, and/or elongated openings defining the “perforations” in the membrane structure of the spargers disclosed herein may be selected to have a maximum opening size width of 1 nanometer to 3 millimeters, or more. For purposes of maintaining fine bubble size distributions and optimal flotation characteristics, the inventors have determined that a maximum opening size width of the perforations (e.g., “slits”) should optimally be maintained at or below approximately 2 millimeters, without limitation.
Where used herein, the term “membrane” may comprise many different materials, including, but not limited to EPDM rubber, silicone rubber, santoprene, gum rubber, natural rubber, neoprene, and/or the like. Thicknesses of the flexible perforated membrane referenced herein may vary, but are preferably greater than 1/16 of an inch (e.g., approximately ⅛″ to ¼″), without limitation.
The above description of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art in light of the above teaching(s). Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. The invention is intended to embrace all alternatives, modifications, and variations of the present invention that have been discussed herein, as well as other embodiments that might clearly fall within the spirit and scope of the above described invention.
In this specification, the terms ‘comprises’, ‘comprising’, ‘includes’, ‘including’, ‘having’, ‘provided with’, or similar terms are intended to mean a non-exclusive inclusion, such that a method, system or apparatus having an inclusion of a list of elements may not necessarily include those elements solely, but may also include other elements not listed. For example, a separator device 100 described herein used for classification purposes may comprise or may not comprise certain features or elements that may be found on a separator device 100 described herein used for flotation purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2022/055014 | 5/27/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63194161 | May 2021 | US |
