Flow control apparatus

Abstract

Disclosed herein is a fluid flow control apparatus, comprising a flow guide (130) upstream of a downstream device (110, 300). The flow guide (130) is configured to adjust a trajectory of a fluid passing it such that the fluid flows toward the downstream device (110, 300) in a desired trajectory, wherein the desired trajectory differs with differing flow rates of the fluid passing the flow guide. A configuration of the flow guide (130) relative to the downstream device (110, 300) is adjustable responsive to a flow rate of the fluid passing the flow guide.

Description

"Flow control apparatus"Cross-Reference

[0001] The present application claims priority from Australian Provisional Patent Application No 2023900727, filed on 16 March 2023, the contents of which are incorporated herein by reference in their entirety.Technical Field

[0002] The disclosure herein relates to a flow control apparatus and an associated method; more particularly, to a flow control apparatus for a screening apparatus that separates solids from a liquid, and an associated method.Background

[0003] There are a variety of known screening apparatus and methods for separating solids from a liquid, such as for the thickening of a slurry or the removal of solids from effluent such as sewage. Some such apparatus and methods involve passing the liquid through a drum screen. Various types of drum screen apparatus are known, including those of: an internally fed type, in which liquid carrying solid material is fed into an interior of the drum screen before passing through apertures in the screen to separate the solid material from the liquid; or an externally fed type, in which liquid carrying solid material is fed onto an exterior of the drum screen before passing through apertures in the screen to separate the solid material from the liquid; in which, in either case, the screen may be: a stationary screen, or a rotating screen, in which the screen may rotate in the same direction as that in which the liquid flows onto the screen or in an opposite direction as that in which the liquid flows onto the screen; and / or a horizontal screen or an inclined screen.

[0004] In an internally fed drum screen apparatus, influent may be pumped or gravity fed into a tank located inside the drum screen. The tank is designed to reduce turbulence of the influent. The influent exits the tank via a weir and falls from the weir onto the interior surface of the drum screen. As the influent passes through the screen apertures, solids are removed from the influent and accumulate inside the screen.

[0005] For optimal screening performance, the influent is introduced to the interior surface of the drum screen substantially tangentially. However, this can be difficult to achieve with known weir configurations, especially in cases where there is substantial variability in influent flow rate, in which: the influent may be introduced to the interior surface of the drum screen substantially tangentially when the influent flow rate is lower but may be introduced to the interior surface of the drum screen more radially when the influent flow rate is higher; and choking of the influent flow between the weir and interior surface of the drum screen can occur when the influent flow rate is higher.

[0006] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.Summary

[0007] Disclosed herein is a flow control apparatus, comprising: a flow guide upstream of a downstream device, the flow guide being configured to adjust a trajectory of a fluid passing the flow guide such that the fluid flows toward the downstream device in a desired trajectory, wherein the desired trajectory differs with differing flow rates of the fluid passing the flow guide; wherein a configuration of the flow guide relative to the downstream device is adjustable responsive to a flow rate of the liquid passing the flow guide.

[0008] The configuration of the flow guide relative to the downstream device being adjustable may comprise a distance between a downstream end of the flow guide and the downstream device being adjustable and / or an orientation of at least a downstream end portion of the flow guide relative to the downstream device being adjustable. For example, the distance between the downstream end of the flow guide and the downstream device may increase in response to an increase in the flow rate of the liquid passing the flow guide and / or at least the downstream end portion of the flow guide may be reoriented from closer to perpendicular to a surface of the downstream device to closer to parallel to the surface of the downstream device in response to an increase in the flow rate of the liquid passing the flow guide. The flow guide may be adjustable between a configuration in which it is substantially planar and a configuration in which it is smoothly curved.

[0009] The flow guide may be resiliently deformable to facilitate the configuration of the flow guide relative to the downstream device being adjustable. A bending stiffness of the flow guide may differ across its width (i.e., between its upstream and its downstream end). Differences in the bending stiffness of the flow guide across its width may, for example, be provided by varying a thickness of flow guide across its width and / or by reinforcing different portions of the width of flow guide to varying extents. The flow guide may be configured to adopt a form approximating that of an ogee weir in response to an increase in the flow rate of liquid passing the flow guide. The flow guide may be formed from a polymer, such as: a synthetic or natural rubber, for example nitrile rubber, nitrile butadiene rubber, EPDM rubber, neoprene rubber, or silicone rubber; polypropylene; or a fluoroelastomer. The polymer may be a fibre- reinforced polymer.

[0010] Alternatively, or in addition, a spring may be connected to the flow guide to facilitate the configuration of the flow guide relative to the downstream device being adjustable.

[0011] The configuration of the flow guide relative to the downstream device may be adjustable responsive to the flow rate of the liquid passing the flow guide by being responsive to a force applied to the flow guide by the liquid.

[0012] The flow guide may take the form of a flap. In some embodiments, the flap may have a thickness of up to about 10mm, or of up to about 5mm or of between about 2mm and about 5mm, or of about 3mm. In other embodiments, the flap may be tubular, and may be generally triangularly shaped in transverse cross section. Internal reinforcing elements may extend longitudinally within the tubular flap. The flap may taper in thickness between its upstream end and its downstream end.

[0013] The flow guide may extend from a fixed component of the apparatus located upstream of the downstream device. An upstream end of the flow guide may be fixedly connected to the fixed component. The flow guide may be cantilevered from the fixed component. A downstream end of the flow guide may be a free end. The flow guide may be removably connected to the fixed component, for example by mechanical fasteners such as threaded fasteners.

[0014] The downstream device may be a screen having an array of apertures therein for screening solids from a liquid carrying the solids, opposing sides of the screen defining an upstream surface for receiving the liquid and a downstream surface from which the liquid is discharged, the apertures extending between the upstream surface and the downstream surface, the flow guide being configured to direct flow of the liquid onto the upstream surface of the screen, and the configuration of the flow guide relative to the screen being adjustable responsive to the flow rate of the liquid passing the flow guide. In a first family of such embodiments, the screen may be a screening drum of a drum screening apparatus. The drum screen apparatus may be of an internally fed type having a tank located inside the screening drum for holding the liquid, the tank having an outlet weir via which the liquid overflows to the screen, wherein the flow guide is connected to and extends from the weir. In a second family of such embodiments, the screen may be a belt screen of a continuous belt screen apparatus.

[0015] A secondary flow control component may extend parallel to and spaced above the flow guide. The secondary flow control component may comprise a flap, which may be formed from the same or similar material to that of the flow guide. The secondary flow control component may be configured to move or flex in response to changes in the flow rate of liquid passing the flow guide. For example, in response to an increase in the flow rate of liquid passing the flow guide, the secondary flow control component may move or flex to increase a liquid flow space defined between the flow guide and the secondary flow control component.

[0016] Also disclosed herein is a method of flow control for the flow control apparatus defined in paragraph

[0007] above, the flow control apparatus optionally including any one or more of the features recited in paragraphs

[0008] to

[0015] above, the method comprising: adjusting the configuration of the flow guide relative to the downstream device in response to a change in the flow rate of the liquid passing the flow guide.

[0017] The method may comprise adjusting a distance between a downstream end of the flow guide and the downstream device and / or an orientation of at least a downstream end portion of the flow guide relative to the downstream device in response to a change in the flow rate of the liquid passing the flow guide. The distance may be increased in response to an increase in the flow rate of the liquid passing the flow guide and / or at least the downstream end portion of the flow guide may be reoriented from closer to perpendicular to a surface of the downstream device to closer to parallel to the surface of the downstream device in response to an increase in the flow rate of the liquid passing the flow guide. The method may comprise adjusting the flow guide between a configuration in which it is substantially planar and a configuration in which it is smoothly curved.

[0018] The method may comprise resiliently deforming, resiliently moving or resiliently reorienting the flow guide to adjust the configuration of the flow guide relative to the downstream device.

[0019] The adjustment of the configuration of the flow guide relative to the downstream device may be in response to a force applied to the flow guide by the liquid.

[0020] Also disclosed is an apparatus or method comprising any and all novel combination of steps, features, integers, compositions and / or compounds disclosed or indicated in the specification of this application, irrespective of whether those steps, features, integers, compositions and / or compounds are disclosed or indicated in relation to an embodiment that also comprises additional steps, features, integers, compositions and / or compounds.

[0021] Throughout this specification the words “comprise”, “include”, “have”, and variations such as “comprises”, “includes”, “has”, “comprising”, “including” and “having”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.Brief Description of Drawings

[0022] One or more embodiment of a device and method embodying principles disclosed herein will now be described, by way of example only, with reference to the accompanying drawings, in which:FIG. l is a schematic view of a first embodiment of a solid-liquid screening apparatus, in which part of the apparatus is shown cut-away to reveal internal components and the large arrows indicate a liquid flow path through the apparatus;FIG. 2 is a cross-sectional view of the apparatus of FIG. 1;FIG. 3 is an enlarged view of a flow control device of the apparatus of FIG. 1, showing the flow control device in a low flow configuration;FIG. 4 is an enlarged view of the flow control device of the apparatus of FIG. 1, showing the flow control device in a high flow configuration;FIG. 5 is a schematic view of part of the apparatus of FIG. 1, but in which an alternative form of flow guide is used; andFIGs. 6 to 8 are schematic views of a liquid flow control apparatus for directing liquid flow to a machine.Description of Embodiments

[0023] Referring to FIGs. 1-5, there is shown a solid-liquid screening apparatus in the form of an internally fed drum screen apparatus 100. Apparatus 100 comprises a screen in the form of a screening drum 110 and a liquid holding tank 120 located inside the screening drum. Tank 120 has an outlet weir 122 via which liquid from the tank overflows to the screening drum 110.

[0024] Screening drum 110 has an array of apertures therein for screening solids out of the liquid received from tank 120. In the illustrated embodiment, screening drum 110 comprises a cylindrical arrangement of wedge wires, with gaps between the wedge wires defining the apertures. Opposing sides 114, 116 of screening drum 110 define, respectively, an upstream surface for receiving the liquid from tank 120 and a downstream surface from which the liquid is discharged, the apertures of screening drum 110 extending between the upstream surface and the downstream surface. Solids screened from the liquid by screening drum 110 are retained within the screening drum. In some embodiments, screening drum 110 rotates and has a screw flight formation 118 on its upstream surface to convey solids that accumulate in the screening drum toward an end of screening drum 110.

[0025] A flow guide 130 extends from weir 122 and is configured to direct liquid overflowing weir 122 onto the upstream surface of screening drum 110. An upstream end 132 of flow guide is removably fixedly connected to weir 122, for example by mechanical fasteners such as threaded fasteners 134. In the illustrated embodiment, flow guide 130 is cantilevered from weir 122, with a downstream end 136 of flow guide 130 being a free end.

[0026] The configuration of flow guide 130 relative to screening drum 110 is adjustable responsive to the flow rate of the liquid passing the flow guide. In theillustrated embodiment, this adjustability comprises a distance between downstream end 136 of flow guide 130 and screening drum 110 being adjustable via adjustment of the orientation of a downstream end portion of the flow guide relative to the screening drum. More specifically, the distance between downstream end 136 of flow guide 130 and screening drum 110 increases in response to an increase in the flow rate of the liquid passing the flow guide due to the downstream end portion of the flow guide being reoriented from closer to perpendicular to the screening drum, as shown in FIG. 3, to closer to parallel to the screen, as shown in FIG. 4. When the flow rate is zero or low, flow guide 130 is substantially planar as shown in FIG. 3, whereas, when the flow rate is higher, flow guide 130 smoothly curved as shown in FIG. 4. In some embodiments, the flow guide 130 adopts a form approximating that of an ogee weir in response to an increase in the flow rate of liquid passing the flow guide.

[0027] Flow guide 130 is resiliently deformable from the planar configuration shown in FIG. 3 to the smoothly curved configuration shown in FIG. 4 in response to the flow rate increasing from zero or a low flow rate to a high flow rate. Flow guide 130 may be formed from a polymer, such as: a synthetic or natural rubber, for example nitrile rubber, nitrile butadiene rubber, EPDM rubber, neoprene rubber, or silicone rubber; polypropylene; or a fluoroelastomer. The polymer may be a fibre-reinforced polymer. The selection of polymer for flow guide 130 may be based on factors such as the nature of the liquid being screened, including the solids carried by that liquid. For example, depending on the nature of the liquid being screened, it may be advisable to select a polymer that has good resistance to one or more of abrasion, chemicals such as cleaning agents, and high temperature environments. In the embodiments illustrated in FIGs. 1-5, which are configured for flow rates of up to 4000 L / min per metre length of weir 122, flow guide 130 takes the form of a nitrile rubber flap having a thickness of approximately 3mm and a width (i.e., distance from its upstream end 132 to its downstream end 136) of approximately 100mm, as shown in FIGS. 1-4, or of a polypropylene rubber flap having a width of approximately 100mm and being configured as shown in FIG. 5. In the embodiment shown in FIG. 5, flow guide 130 comprises a generally triangularly-shaped, tubular flap having internal reinforcing elements extending longitudinally within the tubular flap. In some embodiments, flowguide 130 may be configured such that its bending stiffness differs along its width to configure flow guide 130 to adopt desired curvatures in response to changes in the flow rate of liquid passing thereover. For example, the bending stiffness of flow guide 130 may be higher near its upstream end 132 and lower near its downstream end 136. The variation in bending stiffness across the width of flow guide 130 may, for example, be provided by varying the thickness of flow guide 130 across its width and / or by reinforcing different portions of the width of flow guide 130 to varying extents.

[0028] In alternative embodiments (not shown), flow guide 130 may be hingedly connected to weir 122 and formed from a rigid material, and a spring may be connected to flow guide 130 to facilitate automatic adjustment of the configuration of flow guide 130 relative to screening drum 110.

[0029] As will be appreciated, changes in the flow rate of the liquid passing flow guide 130 cause a corresponding change in the force applied to the flow guide by the liquid. This force is predominantly dictated by the weight of liquid acting on the flow guide 130 at any given time, and to a lesser extent by frictional forces applied to the flow guide by the liquid. In the illustrated embodiment and in embodiments in which flow guide 130 is connected to a spring, these changes in force applied to flow guide 130 cause automatic, resilient reconfiguration of flow guide 130 to increase the space between the downstream end of flow guide 130 and screening drum 110 when the flow rate increases. A subsequent decrease in the flow rate results in a decrease in the force applied to flow guide 130, thereby resulting in flow guide 130 resiliently returning to a configuration in which a downstream end of the flow guide 130 is closer to the screening drum 110. In the illustrated embodiment, flow guide 130 resiliently reconfigures between the substantially planar configuration shown in FIG. 3 when the flow rate is zero or low and the smoothly curved configuration shown in FIG. 4 when the flow rate is higher. More specifically, an increase in the flow rate results in an increase in the force applied to flow guide 130, thereby biasing flow guide 130 toward the curved configuration shown in FIG. 4. A subsequent decrease in the flow rate results in a decrease in the force applied to flow guide 130, thereby resulting in flow guide 130 resiliently returning toward the planar configuration shown in FIG. 3. Inother embodiments, however, a mechanical actuator controlled by an electronic controller may be connected to the flow guide 130 and configured to reconfigure the flow guide relative to the screening drum 110 in response to changes in the flow rate of liquid passing the screening drum.

[0030] In some embodiments, a secondary flow control component may extend along weir 122 parallel to and spaced above flow guide 130. The secondary flow control component may be in the form of a flap, which may be formed from the same or similar material to that of flow guide 130. The secondary flow control component is configured to move or flex in response to changes in the flow rate of liquid passing flow guide 130. For example, in response to an increase in the flow rate of liquid passing flow guide 130, the secondary flow control component may move or flex to increase a liquid flow space defined between flow guide 130 and the secondary flow control component. The action of the secondary flow control component may contribute to flow guide 130 responding in the desired manner to changes in the flow rate of liquid passing flow guide 130.

[0031] Aside from the addition of flow guide 130, and, optionally, the secondary flow control component, apparatus 100 is substantially the same as any of the embodiments of the apparatus described in US Patent No. 4,236,999 from column 3, line 23 to column 6, line 11 with reference to FIGs. 1-6, 10 and 11, with this portion of the disclosure of US Patent No. 4,236,999 being incorporated herein by way of reference. Screening drum 110 may rotate in the same direction as that in which liquid from tank 120 is fed to it, or in a contrary direction, or may be stationary.

[0032] Whilst flow guide 130 has been described with reference to a drum screening apparatus 100, it will be appreciated that it can also be embodied in other types of screening apparatus or other types of apparatus for controlling the flow of liquids. For example, FIGs. 6 to 8 show an apparatus 200 in which flow guide 130 is used to alter the trajectory of a liquid flow such that it interacts with differing parts of a machine 300 dependant on the flow rate of liquid passing the flow guide.

[0033] It will be appreciated that apparatus 100 provides a number of advantages including:• automatic reconfiguration of flow guide 130 into a configuration in which the downstream end portion of flow guide 130 is spaced further from drum screen 110 and / or oriented more closely to parallel to drum screen 110, in response to an increase in influent flow rate, resulting in influent continuing to be introduced to the interior surface of the drum screen 110 substantially tangentially despite the increased flow rate;• automatic reconfiguration of flow guide 130 into a configuration in which the downstream end portion of flow guide 130 is spaced further from drum screen 110 and / or oriented more closely to parallel to drum screen 110, in response to an increase in influent flow rate, reducing choking of influent flow between weir 122 and the interior surface of the drum screen 110;• flow guide 130 being removably connected to weir 122 facilitates flow guide being replaced if worn or if it is desired to install a flow guide having different properties (e.g., due to a change in the nature of the liquid being screened, including the solids carried by that liquid, such as its abrasiveness, its corrosiveness or its temperature);• automatic reconfiguration of flow guide 130 into a form approximating an ogee weir in response to an increase in influent flow rate.

[0034] It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

CLAIMS:

1. A fluid flow control apparatus, comprising: a flow guide upstream of a downstream device, the flow guide being configured to adjust a trajectory of a fluid passing the flow guide such that the fluid flows toward the downstream device in a desired trajectory, wherein the desired trajectory differs with differing flow rates of the fluid passing the flow guide; wherein a configuration of the flow guide relative to the downstream device is adjustable responsive to a flow rate of the fluid passing the flow guide.

2. The apparatus of claim 1, wherein the configuration of the flow guide relative to the downstream device being adjustable comprises a distance between a downstream end of the flow guide and the downstream device being adjustable and / or an orientation of at least a downstream end portion of the flow guide relative to the downstream device being adjustable.

3. The apparatus of claim 2, being configured such that the distance between the downstream end of the flow guide and the downstream device increases in response to an increase in the flow rate of the fluid passing the flow guide and / or at least the downstream end portion of the flow guide is reoriented from closer to perpendicular to a surface of the downstream device to closer to parallel to the surface of the downstream device in response to an increase in the flow rate of the fluid passing the flow guide.

4. The apparatus of any one of claims 1 to 3, wherein the flow guide is adjustable between a configuration in which it is substantially planar and a configuration in which it is smoothly curved.

5. The apparatus of any one of claims 1 to 4, wherein the flow guide is resiliently deformable to facilitate the configuration of the flow guide relative to the downstream device being adjustable.

6. The apparatus of claim 5, wherein the flow guide is formed from a polymer.

7. The apparatus of any one of claims 1 to 6, comprising a spring connected to the flow guide to facilitate the configuration of the flow guide relative to the downstream device being adjustable.

8. The apparatus of any one of claims 1 to 7, wherein the configuration of the flow guide relative to the downstream device is adjustable responsive to the flow rate of the fluid passing the flow guide by being responsive to a force applied to the flow guide by the fluid.

9. The apparatus of any one of claims 1 to 8, wherein the flow guide comprises or takes the form of a flap, wherein the flap may a thickness of up to about 10mm, or of up to about 5mm, or of between about 2mm and about 5mm, or of about 3mm, and wherein the flap may taper in thickness between its upstream end and its downstream end.

10. The apparatus of any one of claims 1 to 8, wherein the flow guide comprises or takes the form of a tubular flap, wherein the tubular flap may be generally triangularly shaped in transverse cross section, wherein internal reinforcing elements may extend longitudinally within the tubular flap, and wherein the tubular flap may taper in thickness between its upstream end and its downstream end.

11. The apparatus of any one of claims 1 to 10, wherein a bending stiffness of the flow guide differs across its width.

12. The apparatus of any one of claims 1 to 11, wherein the flow guide is configured to adopt a form approximating that of an ogee weir in response to an increase in the flow rate of fluid passing the flow guide.

13. The apparatus of any one of claims 1 to 12, wherein the flow guide is connected to and extends from a fixed component of the apparatus located upstream of the downstream device.

14. The apparatus of claim 13, wherein the flow guide is cantilevered from the fixed component.

15. The apparatus of claim 13 or claim 14, wherein the flow guide is removably connected to the fixed component.

16. The apparatus of any one of claims 1 to 15, wherein: the downstream device is a screen having an array of apertures therein for screening solids from a liquid carrying the solids, opposing sides of the screen defining an upstream surface for receiving the liquid and a downstream surface from which the liquid is discharged, the apertures extending between the upstream surface and the downstream surface; and the flow guide is configured to direct flow of the liquid onto the upstream surface of the screen; wherein the configuration of the flow guide relative to the screen is adjustable responsive to the flow rate of the liquid passing the flow guide.

17. A drum screening apparatus comprising the flow control apparatus of claim 16, wherein the screen is a screening drum of the drum screening apparatus.

18. The drum screening apparatus of claim 17, being of an internally fed type having a tank located inside the screening drum for holding the liquid, the tank having an outlet weir via which the liquid overflows to the screen, wherein the flow guide is connected to and extends from the weir.

19. A continuous belt screen apparatus comprising the flow control apparatus of claim 16, wherein the screen is a belt screen of the continuous belt screen apparatus.

20. A method of flow control for the apparatus of any one of claims 1 to 19, the method comprising: adjusting the configuration of the flow guide relative to the downstream device in response to a change in the flow rate of the fluid passing the flow guide.

21. The method of claim 20, comprising adjusting a distance between a downstream end of the flow guide and the downstream device and / or an orientation of at least a downstream end portion of the flow guide relative to the downstream device in response to a change in the flow rate of the fluid passing the flow guide.

22. The method of claim 20 or claim 21, comprising resiliently deforming, resiliently moving or resiliently reorienting the flow guide to adjust the configuration of the flow guide relative to the downstream device.

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