MULTI-CHAMBERED HYDROCLONE
A hydroclone (10) having a tank (12) including a fluid inlet (14), a filtered fluid outlet (16), an effluent outlet (18), a process fluid outlet (20) and an inner peripheral wall (22) enclosing a plurality of vertically aligned chambers (24, 30, 32). In one embodiment the tank (12) includes three vertically aligned chambers including a vortex chamber (24) in fluid communication with the fluid inlet (14). A filter assembly (26) is located within the vortex chamber (24) and encloses a filtrate chamber (66). The vortex chamber (24) includes a fluid pathway (28) adapted for receiving incoming fluid and generating a vortex fluid flow about the filter assembly (26). The filtrate chamber (56) is in fluid communication with the filtered fluid outlet (16) such that fluid passing through the filter assembly (26) enters the filtrate chamber (56) and may exit the tank (12) by way of the filtered fluid outlet (16). An effluent separation chamber (30) is located below and in fluid communication with the vortex chamber (24) and is adapted for receiving unfiltered fluid from the vortex chamber (24). A process fluid chamber (32) is located below and in fluid communication with the effluent separation chamber (30) and is adapted for receiving a process fluid from the effluent separation chamber (30) wherein the process fluid chamber (32) is in fluid communication with the process fluid outlet (20) by which process fluid may exit the tank (12). A vortex flow barrier (34) is located between the vortex and effluent separation chambers (24, 30) and disrupts vortex fluid flow from the vortex chamber (24) to the effluent separation chamber (30). An effluent barrier (36) is located below the effluent separation chamber (30) and directs fluid flow from the effluent separation chamber (30) to the process fluid outlet (20), and wherein the effluent barrier (36) further comprises a centrally located effluent opening (38) in fluid communication with the effluent outlet (18) by which effluent may exit the tank (12). A hydrodone (10) having a tank (12) including a fluid inlet (14), a filtered fluid outlet (16), an effluent outlet (18), a process fluid outlet (20) and an inner peripheral wall (22) enclosing a plurality of vertically aligned chambers (24, 30, 32). In one embodiment the tank (12) includes three vertically aligned chambers including a vortex chamber (24) in fluid communication with the fluid inlet (14). A filter assembly (26) is located within the vortex chamber (24) and encloses a filtrate chamber (66). The vortex chamber (24) includes a fluid pathway (28) adapted for receiving incoming fluid and generating a vortex fluid flow about the filter assembly (26).
This application claims priority from U.S. Provisional Application No. 61/483221 filed 6 May 2011, the entire subject matter of which is incorporated by reference.
TECHNICAL FIELDThe invention is generally directed toward hydroclones and cyclonic separation of fluids.
BACKGROUNDHydroclones are commonly used to separate suspended particles from liquids. In a typical embodiment, pressurized feed liquid (e.g. waste water) is introduced into a conically shaped chamber under conditions that create a vortex within the chamber. Generally, feed liquid is introduced near the top of a conical chamber and an effluent stream is discharged near the bottom of the chamber. Centrifugal forces associated with the vortex urge denser particles towards the periphery of the chamber. As a result, liquid located near the center of the vortex has a lower concentration of particles than that at the periphery. This “cleaner” liquid can then be withdrawn from a central region of the hydroclone. Examples of hydroclones are described in: U.S. Pat. Nos. 3,061,098, 3,529,724, 5,104,520, 5,407,584 and 5,478,484. Separation efficiency can be improved by including a filter within the chamber such that a portion of the liquid moving to the center of the chamber passes through the filter. In such embodiments, cyclonic separation is combined with cross-flow filtration. Examples of such embodiments are described in: U.S. Pat. No. 7,632,416, U.S. Pat. No. 7,896,169, US2011/0120959 and US2012/0010063. While such hybrid designs improve separation efficiency, further improvements are desired. The entire subject matter of each of the previously cited references is incorporated herein by reference.
SUMMARYThe invention includes multiple embodiments of hydroclones and methods for performing cyclonic separations using the same. In one embodiment, the invention includes a hydroclone (10) having a tank (12) including a fluid inlet (14), a filtered fluid outlet (16), an effluent outlet (18), a process fluid outlet (20) and an inner peripheral wall (22) enclosing a plurality of vertically aligned chambers. While differing numbers of chambers may be used, in one embodiment the tank (12) includes three vertically aligned chambers including a vortex chamber (24) in fluid communication with the fluid inlet (14). A filter assembly (26) is located within the vortex chamber (24) and encloses a filtrate chamber (66). The vortex chamber (24) includes a fluid pathway (28) adapted for receiving incoming fluid and generating a vortex fluid flow about the filter assembly (26). The filtrate chamber (56) is in fluid communication with the filtered fluid outlet (16) such that fluid passing through the filter assembly (26) enters the filtrate chamber (56) and may exit the tank (12) by way of the filtered fluid outlet (16). An effluent separation chamber (30) is located below and in fluid communication with the vortex chamber (24) and is adapted for receiving unfiltered fluid from the vortex chamber (24). A process fluid chamber (32) is located below and in fluid communication with the effluent separation chamber (30) and is adapted for receiving a process fluid from the effluent separation chamber (30) wherein the process fluid chamber (32) is in fluid communication with the process fluid outlet (20) by which process fluid may exit the tank (12). A vortex flow barrier (34) is located between the vortex and effluent separation chambers (24, 30) and disrupts vortex fluid flow from the vortex chamber (24) to the effluent separation chamber (30). An effluent barrier (36) is located below the effluent separation chamber (30) and directs fluid flow from the effluent separation chamber (30) to the process fluid outlet (20), and wherein the effluent barrier (36) further comprises a centrally located effluent opening (38) in fluid communication with the effluent outlet (18) by which effluent exits the tank (12). Multiple embodiments are described.
Various aspects of the invention may be better understood by reference to the following description taken in conjunction with the accompanying drawings wherein like numerals have been used throughout the various views to designate like parts. The depictions are illustrative and are not intended to be to scale or otherwise limit the invention.
The present invention generally relates to the hydroclone filtration devices and related methods of conducting cyclonic separation. For purposes of the present description, the term “hydroclone” refers to a filtration device that at least partially relies upon centrifugal forces generated by vortex fluid flow to separate constituents from a fluid mixture. Examples include the separation of solid particles from a liquid mixture and separation of mixtures including liquids of differing densities (e.g. oil and water). Specific applications include the treatment of: pulp effluent generating by paper mills, process water generated by oil and gas recovery, bilge water and municipal and industrial waste water.
One embodiment of the invention is illustrated in
The tank (12) includes a vortex chamber (24) in fluid communication with the fluid inlet (14). A filter assembly (26) is centrally located within the vortex chamber (24) and encloses a filtrate chamber (66), (as best shown in
A vortex flow barrier (34) is located between the vortex and effluent separation chambers (24, 30) and directs fluid flow between the vortex and effluent separation (24, 30) chambers to locations adjacent to the inner peripheral wall (22) of the tank (12). The vortex flow barrier (34) may be designed to maintain vortex fluid flow in the effluent separation chamber (24) and disrupt vortex fluid flow (28) as fluid flows from the vortex chamber (24) into the effluent separation chamber (30). More specifically, the vortex flow barrier (34) includes an outer periphery (40) extending to locations adjacent to or in contact with the inner peripheral wall (22) of the tank (12) and may further include a plurality of apertures (42) located near the periphery (40) and extending therethrough. In the illustrated embodiment, the apertures (42) are scalloped-shaped but alternative shapes may also be used (as best shown in
An effluent barrier (36) is located below the effluent separation chamber (30) and is adapted to direct fluid flow from the effluent separation chamber (30) to the process fluid outlet (20). The effluent barrier (36) includes an outer periphery (40′) extending to locations adjacent to or in contact with the inner peripheral wall (22) of the tank (12) and may further include a plurality of apertures (42′) located near the periphery (40′) and extending therethrough. In the illustrated embodiment, the apertures (42′) are scalloped-shaped but alternative shapes may also be used (as best shown in
In operation, pressurized feed fluid (e.g. preferably from 4 to 120 psi) enters the tank (12) via the fluid inlet (14) and follows along fluid pathway (28) which generates a vortex about the filter assembly (26). Centrifugal forces urge denser materials toward the inner peripheral wall (22) of the tank (12) while less dense liquid flows radially inward toward the filter assembly (26). A portion of this liquid flows through the filter assembly (26) into a filtrate chamber (66) and may subsequently exit the tank (12) as “filtrate” by way of the filtered fluid outlet (16). The remaining “non-filtrate” flows downward from the vortex chamber (24) to the effluent separation chamber (30). The vortex flow barrier (34) directs the majority (e.g. preferably at least 75% and in some embodiments at least 90%) of such downward flow to locations along or adjacent to an inner peripheral wall (22) of the tank (12). This arrangement is believed to help maintain vortex flow within the vortex chamber (24) while disrupting the vortex flow as fluid enters the effluent separation chamber (30). Fluid flow slows in the effluent separation chamber (30) and denser materials (e.g. particles) preferentially settle toward the center of the effluent barrier (34) and enter into the effluent opening (38) and may then exit the tank by way of effluent outlet (18). The effluent outlet (18) may optionally include a valve (48) (e.g. one-way check value) to selectively control removal of effluent from the tank (12). The remaining liquid (hereinafter referred to as “process fluid”) in the effluent separation chamber (30) flows downward into the process fluid chamber (32). The effluent barrier (36) directs a majority (e.g. preferably at least 75% and in some embodiments at least 90%) of fluid flow between the effluent separation vortex and process fluid chambers (34, 36) to locations along or adjacent to an inner peripheral wall (22) of the tank (12), i.e. through apertures (42′). In most applications, process fluid represents a mid-grade product that may be re-used, disposed of or recycled back to the fluid inlet (14) for further treatment. “Filtrate” typically represents a high grade product that may be re-used or disposed of. “Effluent” represents a low grade product that may be further treated or disposed of. However, it should be appreciated that in some applications, effluent may represent a valuable product.
The feed fluid inlet pressure and spacing between the outer periphery of the filter assembly (26) and the inner peripheral wall (22) of the tank (12) can be optimized to create and maintain a vortex fluid flow within the vortex chamber (24). In order to further facilitate the creation and maintenance of vortex fluid flow, the fluid inlet (14) preferably directs incoming feed fluid on a tangential path about the vortex chamber, as indicated by dotted arrows in
Ideal configurations of the vortex flow barrier (34) and effluent barrier (36) can be determined based upon the operating conditions of the hydroclone and composition of the feed fluid. A variety of embodiments of the effluent barrier (36) are illustrated in
While in one embodiment the effluent barrier (36) includes scalloped-shaped apertures (42′), alternatively shaped apertures may also be used including radial slots, angled slots and triangular openings located about the outer periphery (40′), as illustrated in
As shown in
The subject hydroclone (10) may further include a cleaning assembly (68) for removing debris from the membrane surface (64) of the filter assembly (26). A representative embodiment is illustrated in
An alternative embodiment of the hydroclone (10) including a cylindrical tank (12) is illustrated in
By way of further illustration, four different hydroclones were tested using an aqueous feed fluid including 2000 ppm of 200 pm plastic particles having a specific gravity of 1.1. The hydroclones had the general configuration as shown in
Hydroclone 1 (♦) included no effluent barrier (36).
Hydroclone 2 (▪) included a flat circular effluent barrier (36) with no apertures (42′) and had a diameter approximately 10 mm less than the inner diameter of the tank (12).
Hydroclone 3 () included a flat circular effluent barrier having a diameter extending to the inner peripheral wall (22) of the tank (12) and which had scallop-shaped apertures (42′) as illustrated in
Hydroclone 4 (▴) included a cone-shaped effluent barrier having a diameter extending to the inner peripheral wall (22) of the tank (12) and including scalloped-shaped apertures (42′) as illustrated in
All Hydroclones were tested under the same conditions. More specifically, 100 gallons (378.5 l) of feed fluid was pumped into the feed inlet (14) of the hydroclone at a rate of 30 gpm (112.6 l/minute) from a holding tank. Filtrate was removed from the filtered fluid inlet (16) at a rate of 30 gpm (112.6 l/minute) and was returned to the holding tank. The pressure differential across the filter substrate (54) was approximately 0.5 psi (3.5 KPa). Process fluid from the process fluid outlet (20) was re-circulated and re-introduced into the fluid feed inlet (14) at a rate of 120 gpm (454.2 l/min). Every six minutes, the valve (48) was opened to remove and analyze the effluent (plastic particles). The results of the testing are summarized in
The subject hydroclones provide unexpectedly superior separation efficiencies as compared with previous designs. These efficiencies allow the hydroclone to be used a broader range of applications; particular in embodiments where process fluid is recycled and optionally blended with make-up feed fluid. Broadly stated, feed fluid is subjected to a synergistic combination of multiple separation processes within a single device. Specifically, feed fluid is subject to cyclonic separation based at least partially upon density with denser material (e.g. particles, liquids) being urged toward the inner periphery of the tank. Fluid passing through the filter assembly is additionally subjected to cross-flow separation. While separation through the filter assembly may he based upon particle size, other means of separation may also be used depending upon the selection of separation media utilized in the filter assembly. For example, separation may also be based at least partially upon hydrophilicity or charge density. While not wishing to be bound by theory, the effluent barrier is believed to provide yet another means of separation as the flow of denser materials or larger particles slows and the radial fluid velocity drag forces exceed any residual centrifugal forces lingering from the vortex such that these denser materials (e.g. particles, liquids) are collected within the effluent opening. These synergistic separations are further enhanced by the use of barriers (34, 36) that limit fluid flow in constrained areas about the inner peripheral wall of the hydroclone tank. The use of a cleaning assembly may still further enhance separations by clumping debris from the filter assembly and thereby add to its effective particle size or density, both of which are believe to improve separation in the effluent chamber.
Claims
1. A hydroclone (10) comprising a tank (12) including a fluid inlet (14), a filtered fluid outlet (16), an effluent outlet (18), a process fluid outlet (20) and an inner peripheral wall (22) enclosing a plurality of vertically aligned chambers comprising:
- a vortex chamber (24) in fluid communication with the fluid inlet (14), a filter assembly (26) located within the vortex chamber (24) and enclosing a filtrate chamber (56), a fluid pathway (28) adapted for receiving incoming fluid and generating a vortex fluid flow about the filter assembly (26), wherein the filtrate chamber (66) is in fluid communication with the filtered fluid outlet (16) such that fluid passing through the filter assembly (26) enters the filtrate chamber (56) and exits the tank (12) by way of the filtered fluid outlet (16),
- an effluent separation chamber (30) located below and in fluid communication with the vortex chamber (24) which is adapted for receiving unfiltered fluid from the vortex chamber (24),
- a process fluid chamber (32) located below and in fluid communication with the effluent separation chamber (30) which is adapted for receiving a process fluid from the effluent separation chamber (30) and wherein the process fluid chamber (32) is in fluid communication with the process fluid outlet (20) by which process fluid exits the tank (12),
- a vortex flow barrier (34) located between the vortex and effluent separation chambers (24, 30) which disrupts vortex fluid flow (28) as fluid flows from the vortex chamber (24) to the effluent separation chamber (30), and
- an effluent barrier (36) located below the effluent separation chamber (30) which directs fluid flow from the effluent separation chamber (30) to the process fluid outlet (20), and wherein the effluent barrier (36) further comprises a centrally located effluent opening (38) in fluid communication with the effluent outlet (18) by which effluent exits the tank (12).
2. The hydroclone (10) of claim 1 wherein the vortex flow barrier (34) directs a majority of fluid flow between the vortex and effluent separation (24, 30) chambers to locations adjacent to the inner peripheral wall (22) of the tank (12).
3. The hydroclone (10) of claim 1 wherein the effluent barrier (36) limits a majority of fluid flow between the effluent separation and process fluid chambers (34, 36) to locations adjacent to the inner peripheral wall (22) of the tank (12).
4. The hydroclone (10) of claim 1 wherein the effluent barrier (36) further comprises an outer periphery (40′) extending to locations adjacent to the inner peripheral wall (22) of the tank (12), and further comprises a plurality of apertures (42′) extending therethrough.
5. The hydroclone (10) of claim 1 wherein at least one of the vortex flow barrier (34) and effluent barrier (36) comprise a plate-shaped configuration.
6. The hydroclone (10) of claim 1 wherein the vortex flow barrier (34) and effluent barrier (36) both comprise configurations including an outer periphery (40, 40′) extending to locations adjacent to the inner peripheral wall (22) of the tank (12), and further comprise a plurality of apertures (42, 42′) extending through the barriers (34, 36) at locations adjacent to their outer periphery (40, 40′) that permit fluid flow therethrough.
7. The hydroclone (10) of claim 6 wherein the apertures (42) of the vortex flow barrier (34) are vertically off-set from the apertures (42′) of the effluent barrier (36).
8. The hydroclone (10) of claim 1 wherein the effluent barrier (36) comprises a central region that is lower or higher than the outer periphery (40).
Type: Application
Filed: May 1, 2012
Publication Date: Feb 13, 2014
Inventors: John H. Mallard (Saratoga, CA), Eugene A. McKay (Woodside, CA), Steven E. O'Reilly (Menlo Park, CA), Scott T. Burr (Midland, MI)
Application Number: 13/581,578
International Classification: B01D 21/26 (20060101); B01D 21/00 (20060101);