Abstract
Apparatus for separating grit from a grit-loaded liquid matrix while retaining organic solids in suspension, including an inlet for admitting liquid matrix into the apparatus, an outlet for removing grit-lite liquid matrix from the apparatus main chamber, and a vortex system for removing separated liquid matrix grit from the apparatus. The grit settling main chamber defines upper and lower subchambers communicating with each other through a central aperture. A fluid flow speed gradient is established between the apparatus fluid inlet and outlet. An Eddy type fluid dynamic component is added, providing combined enhanced coarse grit and fine organics discrimination and separation. The Eddy fluid dynamic component may consist of a trio of stationary fresh water supply force fed eductors. Each eductor produces a fresh water fluid flow interacting with the liquid matrix fluid flow inside the upper subchamber, whereby Eddy-type turbulences are generating promoting fine, liquid matrix grit particle separation from the liquid matrix.
Claims
1. An apparatus for separating grit from a grit-loaded liquid matrix while retaining liquid matrix organic solids in suspension and water, including inlet means for admitting the liquid matrix into the apparatus, outlet means for removing grit-lite liquid matrix from the apparatus, and means for removing separated grit from the apparatus, the apparatus further comprising: a cylindrical grit settling main chamber defining a bottom end portion, a top end and a peripheral wall; said means for removing separated grit from the apparatus cooperating with said main chamber bottom end portion; a secondary chamber including a central grit settling access top mouth opening through said main chamber bottom end portion; a partition extending transversely through said main chamber intermediate said top end and said bottom end portion thereof spacedly therefrom wherein an upper subchamber is formed in said main chamber above said partition and a lower subchamber is formed in said main chamber below said partition, said liquid matrix inlet means in direct fluid communication with said lower subchamber, said grit-lite liquid matrix outlet means in direct fluid communication with said upper subchamber, said partition having a peripheral edge, integrally mounted in substantially fluid tight fashion to said peripheral wall of said main chamber, and a central aperture; wherein a liquid matrix fluid flow speed gradient is established between said upper and lower subchambers through said partition central aperture; and further including a turbulence generating fluid dynamic component, mounted inside said upper subchamber and providing enhanced fine grit separation from said liquid matrix, said fluid dynamic component producing Eddy-type turbulences inside said upper subchamber.
2. The apparatus as in claim 1, wherein said turbulence generating fluid dynamic component includes at least one eductor, fixedly mounted inside said upper subchamber, and a fresh water supply means force fed to said eductor.
3. The apparatus as in claim 2, wherein said at least one eductor generates eductor fluid flows in the same direction of flow than that of the liquid matrix inside said upper subchamber.
4. The apparatus as in claim 2, wherein said at least one eductor generates eductor fluid flows in the opposite direction of flow relative to that of the liquid matrix inside said upper subchamber.
5. The apparatus as in claim 2, wherein there are three stationary eductors fixedly mounted to said main chamber peripheral wall in radially equidistant fashion to one another.
6. The apparatus as in claim 5, wherein said eductors generate eductor fluid flows in the same direction of flow than that of the liquid matrix inside said upper subchamber.
7. The apparatus as in claim 5, wherein said eductors generate eductor fluid flows in the opposite direction of flow relative to that of the liquid matrix inside said upper subchamber.
8. The apparatus as in claim 5, wherein said upper subchamber is further subdivided into a top subchamber and an intermediate subchamber, said eductors mounted inside said intermediate subchamber, wherein an annular horizontal ring is formed between said top and intermediate subchambers and fixedly mounted tangentially to said main chamber peripheral wall and defining a central bore, and further including an annular vertical wall mounted within said ring central bore and projecting upwardly therefrom short of said main chamber top end, wherein said annular vertical wall forms a radially outward overflow surface for said grit-lite liquid matrix.
9. The apparatus as in claim 8, wherein said eductors generate eductor fluid flows in the same direction of flow than that of the liquid matrix inside said intermediate subchamber.
10. The apparatus as in claim 8, wherein said eductors generate eductor fluid flows in the opposite direction of flow relative to that of the liquid matrix inside said intermediate subchamber.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is an isometric schematic view of a grit removal apparatus, suggesting fluid dynamics where relative intake and outflow fluid flow speeds are correlated with arrow bands width;
[0025] FIGS. 2 and 3 are isometric views of a first embodiment of grit removal apparatus according to the present invention, with three illustrated forward flow eductors, at 10 and 3 million United States Gallons per day (MGD) flow rates respectively, suggesting fluid dynamics at up to 3 meters/second velocity streamline;
[0026] FIGS. 4 and 5 are isometric views of a second embodiment of grit removal apparatus with three illustrated reverse flow eductors at 10 and 3 MGD fluid flow rates respectively, suggesting fluid flow and fluid dynamics at up to 3 meters/second velocity streamlines;
[0027] FIG. 6 shows an isometric view of a grit removal apparatus with horizontal ring grit remover, at 10 MGD flow rate, suggesting fluid dynamics at up to 3.37 meters/sec velocity streamline;
[0028] FIG. 7 shows an isometric view of the grit removal apparatus of FIG. 6, but without fluid flow arrow bands for clarity of the view;
[0029] FIG. 8 shows an isometric view of a third embodiment of grit removal apparatus, with three reverse flow eductors mounted into the grit removal chamber of FIGS. 6-7, and suggesting fluid dynamics at up to 1 meter/sec velocity streamline;
[0030] FIG. 9 shows an isometric view of a fourth embodiment of grit removal apparatus, with three forward flow eductors mounted into the grit removal chamber, and suggesting fluid dynamics of up to 25 meters/sec velocity streamline;
[0031] FIG. 10 is an enlarged isometric view of an eductor, suggesting an expelled first fluid flow (pressurized air or fresh water) at a smaller speed (narrower arrow bands) relative to greater speed upstream intake second fluid flow;
[0032] FIG. 11 is an enlarged schematic view of an eductor, at a smaller scale than FIG. 10, suggesting operational fluid dynamics with velocity swirling counter current flows generated upstream of the stationary eductor intake water flow fed to this “reverse flow” eductor, and the Eddy turbulence dissipation generated downstream of this stationary reverse eductor at the Eddy creation organic separation zone;
[0033] FIG. 11A is a view similar to FIG. 11 but with the reverse eductor replaced by a “forward flow” educator, with Eddy turbulence dissipation being generated downstream of this stationary forward eductor;
[0034] FIG. 12 is an elevational partly sectional view of the grit removal apparatus embodiment of FIGS. 6-9, with ground supporting frame and showing the central vertical shaft supporting at its bottom end two eductor-carrying radial arms and connected at its top end to a motorized water supply pump for feeding fresh water to the eductors;
[0035] FIG. 13 is an enlarged top plan view of the triplet stationary eductors radially spacedly carried by the central shaft by three corresponding radial arms A1, A2 and A3, and suggesting fluid intake and fluid outlet flows with arrow bands on one eductor;
[0036] FIGS. 14 and 15 disclose two tables showing performance parameters in rows and columns in operating conditions of a grit removal apparatus at 10 and 3 MGD flow rate, respectively, accordingly to the grit removal apparatus as shown in FIG. 1;
[0037] FIGS. 16 and 17 disclose two other tables showing performance parameters in rows and columns for particle tracking with forward flow eductors mounted to the first embodiment of FIGS. 2 and 3 of grit removal apparatus at 10 and 3.57 MGD flow rate respectively, with parameters in the tables suggesting performance improvement from addition of eductors;
[0038] FIGS. 18, 19 and 20 disclose three other tables showing performance parameters in rows and columns for particle tracking with reverse flow eductors mounted inside a grit removal apparatus at 10, 3.57 and 10 MGD flow rate respectively, according to the second embodiment of the invention illustrated in FIGS. 4 and 5, with FIG. 18 suggesting slight overall performance improvement while FIG. 19 suggesting performance improvement on small flow speeds for fine sized particles, and FIG. 20 disclosing performance parameters for particle tracking with eductors reverse flow at double flow rate mounted to a grit removal apparatus;
[0039] FIGS. 21 and 22 disclose two other tables showing performance parameters in rows and columns for particle tracking in an eductor-less grit removal apparatus at 10.47 and 3 MGD flow rates respectively, according to the embodiment of FIGS. 6-7;
[0040] FIG. 23 discloses another table showing performance parameters in rows and columns for particle tracking with forward flow rate eductors at 3 MGD in a grit removal apparatus, according to the embodiment at FIG. 8, and suggesting increased performance in fine particles; and
[0041] FIGS. 24 and 25 disclose two other tables showing performance parameters in rows and columns for particle tracking with reverse flow eductors, at 10 and 3 MGD respectively, in a grit removal apparatus according to the second embodiment of the invention, as illustrated in FIG. 9, and with FIG. 24 suggesting increased performance at low fluid flow speeds with Eddy-type turbulence dissipation.
DETAILED DESCRIPTION OF THE INVENTION
[0042] FIG. 1 schematically shows a number of major components in an apparatus for separating grit from incoming grit-loaded waste water (or “liquid matrix”), 100. Apparatus 100 includes a main cylindrical settling chamber 102, disposed immediately above and concentric to an underlying diametrally smaller secondary cylindrical grit channel 104 and downward coaxial funnel member 112.
[0043] As illustrated in FIG. 12, the bottom end portion of funnel member 412 (112) includes a transverse bore 412A through which escapes a tubular member 403. Tubular member 403 thus transversely projects from funnel member 112 (412) and designed to be coupled to a grit extraction pump (not shown) for forcibly removing separated grit through funnel member 412. However grit removal pump and associated funnel member 412 (112) could be replaced by any other suitable grit removal means, e.g. power operated, grit well fed under gravity borne forces, or otherwise. Chamber 102 defines an upright peripheral wall 106 and a top horizontal 108. A vertical cylindrical chute 104 opens at mouth 104A through bottom wall 110. Funnel member 112 downwardly axially depends from chute 104, for grit discharge through grit outlet tube 403A. Chamber 102 is supported in upright condition over ground by frame 405 (FIG. 12).
[0044] A planar horizontal, or horizontal conical partition 114 as shown, is mounted into main chamber 102 spacedly above flooring 110 and spacedly below main chamber top wall 108. Partition 114 defines a central mouth 120, and merges in fluid tight fashion at its radially outward edge with peripheral wall 106. Top wall 108 also includes a central aperture 108A coaxial with mouth 120.
[0045] Accordingly, an upper subchamber 102A is formed between the partition 114 and the top wall 108 of main chamber 102, and a lower subchamber 102B is formed between the partition 114 and the flooring 110 of chamber 102, wherein subchambers 102A and 102B come in fluid communication only through radially inward central mouth 120 of partition 114. In one embodiment, flooring 110 is downwardly conical.
[0046] Partition 114 is sized and shaped relative to grit settling chamber 102 in such a fashion as to restrict all vortex induced upward flow of liquid matrix only through partition central mouth 120. The liquid matrix partially purged from grit from the original grit loaded liquid matrix coming from incoming waste water fluid flows F1 and F2, is not allowed to flow upwardly between the sealed radially outward peripheral edge portion of partition 114 and the peripheral wall 106 of grit settling chamber 102, so that all water flow between sub-chambers 102A and 102B occur only through central mouth 120.
[0047] A fluid intake port 128 transversely opens through upright peripheral wall 106 and into lower subchamber 102B. A grit loaded liquid matrix intake channel 130 opens at one end into intake port 128, for ingress into subchamber 102B of liquid matrix flows F1 and F2. Channel 130 tangentially intersects the lower portion of main settling chamber wall 106 so as to cause the incoming influent liquid matrix to flow tangentially into lower subchamber 102B. A centrifugal force is generated for the liquid matrix fluid engaging inside cylindrical lower subchamber 102B, which brings about liquid matrix flow forcibly radially outwardly against the interior wall of lower subchamber 102B. Accordingly, liquid matrix flow is designed to flow coaxially through inlet port 128 and into subchamber 102B at substantial flow speeds F1 and F2, with wider arrow bands F2 indicating higher fluid flow speed and with narrower arrow band F1 indicating smaller fluid flow speed.
[0048] A fluid outlet port 132 transversely opens through upright wall 106 and into upper subchamber 102A. Fluid channel 134 transversely opens at one end into fluid outlet port 132 along an axis offset relative to that of fluid inlet channel 130, for outflow escape of grit-lite liquid matrix (including water and organic solids in suspension and substantially decreased concentration of grit) from upper subchamber 102A and into fluid outlet channel 134. In one embodiment, grit-lite liquid matrix is a completely grit-less liquid matrix.
[0049] After liquid matrix flows F1 and F2 have engaged into lower subchamber 102B, a clockwise rotational current flow F3 is formed therein; grit-lite liquid matrix escapes upwardly through partition central mouth 120 and into upper chamber 102A, where a further clockwise rotational flow current F4 occurs, to be able thereafter to escape tangentially through channel 134 along fluid flow F5. Grit released from the grit-lite liquid matrix falls by gravity from lower subchamber 102B through mouth 104A, into funnel body 104, 112, through escape bore 412A and beyond along tubular member 403A.
[0050] In the embodiment of FIGS. 2-3, at least one, and for example three forward flow eductors 250, 252, 254, are mounted in stationary fashion radially spacedly inside upper subchamber 202A, spacedly beneath the top wall 208 and spacedly above partition 214. Corresponding 100-series elements from FIG. 1 can be found under 200-series numerals in the embodiment of FIGS. 2-3, under 300-series numerals in the embodiment of FIGS. 4-5, under 400-series numerals in the embodiment of FIGS. 6-8 and 11-12, and under 500-series numerals in the embodiment of FIGS. 9 and 11A.
[0051] Each forward flow eductor 250, 252, 254, ejects fresh water supplied from an outside source into upper subchamber 202A in a forward fashion, i.e. in the general rotational clockwise direction of waste water flow F7, the latter coming from flow F6 in underlying lower subchamber 202B and through partition central mouth 220. FIG. 3 shows different flow rates F9, F10 and F11 under different fluid feed loads.
[0052] FIG. 4 shows a grit removal apparatus 300 whose upper subchamber 302A supports three “reverse flow” type eductors 350, 352, 354, mounted in stationary position radially spacedly beneath top wall 308 and spacedly above partition 314. Alternate numbers of eductors may replace the trio of eductors 350, 352, 354, e.g. a single eductor, two eductors, four eductors, or more. Fluid flows F20 and F21 enter inlet channel 330, generating a clockwisely rotating flow F22 inside lower subchamber 302B, with grit-lite liquid matrix then passing upwardly through partition central mouth 320 into upper subchamber 302A along clockwise flows F23 while separated grit, in particular fine sized grit (e.g. in the 100 to 150 micrometers range) fall under gravity forces through outlet mouth 312A towards grit storage area 403. Grit-lite liquid matrix flow F24 exits through duct 334. FIG. 5 is similar to FIG. 4 but shows alternate load feed fluid flows F20′ and F21′ and corresponding chamber fluid flows F22′ and F23′ and outflow fluid flow F24′.
[0053] FIGS. 6 to 9 disclose an alternate grit removal chamber 400 where the upper subchamber 402A includes in addition: [0054] a. a horizontal annular ring 413 defining a central aperture 413A and extending intermediate partition 414 and top wall 408 spacedly therefrom; and [0055] b. an annular vertical wall 411, transversely mounted around partition central aperture 413A of horizontal ring 413 but extending upwardly short of top wall 408.
[0056] Horizontal annular ring 413 thus extends radially outwardly from the annular vertical wall 411 within upper subchamber 402A, so that upper subchamber 402A is divided into two separate subchambers 402C and 402D.
[0057] Grit loaded liquid matrix supply fluid flow F25 enters lower subchamber 402B through duct 430, wherein first clockwise flow F26 is generated; grit-lite liquid matrix moves upwardly through partition central aperture 420 into intermediate chamber 402C and generates second clockwise rotating flows F27. Third clockwise fluid flow F28 is generated upon elbowed central fluid flow F20 passing through the central bore 413A of ring 413 and radially outwardly overflows over annular vertical wall 411 to reach uppermost subchamber 402D. Grit-Ite liquid matrix flow F30 then exits through outlet duct 434.
[0058] FIG. 8 discloses three reverse flow type eductors 450, 452 and 454 mounted in stationary condition inside intermediate subchamber 402C of grit removal chamber 402, in the same relative radial position as with previous embodiments. Incoming liquid matrix flow F31 generates clockwisely rotating liquid matrix flow F32 inside lower subchamber 402B, clockwisely rotating liquid matrix flow F33 inside intermediate subchamber 402C, elbowed grit-lite liquid matrix flow F34 overflowing radially outwardly over annular vertical wall 411 and clockwisely rotating grit-lite liquid matrix flow F35 inside upper subchamber 402A, before escaping radially outwardly through duct 434 along grit-lite liquid matrix fluid flow F36.
[0059] FIG. 9 discloses three forward flow type eductors 550, 552, 554, mounted in stationary fashion inside intermediate subchamber 502C of grit removal chamber 502, in the same relative radial positioning as with previous embodiments. Incoming grit loaded liquid matrix waste water flow F37 generates clockwisely rotating first liquid matrix flow F38 inside lower subchamber 502B, then clockwisely rotating flow F39 inside intermediate subchamber 502C, then elbowed grit-lite liquid matrix flow F39 overflowing radially outwardly over annular vertical wall 511, and clockwisely rotating grit-lite liquid matrix flow F41 inside intermediate subchamber 502A, before escaping radially outwardly through duct 534 along grit-lite liquid matrix fluid flow F42.
[0060] FIGS. 8, 12 and 13 show how fresh water is supplied to the eductors: a hollow shaft 445 extends vertically through mouth 408A of main chamber top wall 408 and into upper subchamber 402A, and is supported in position by brackets 490 integrally to chamber peripheral wall (106—see FIG. 1). A flexible water line 460 extends freely through the hollow of shaft 445 and opens at its top end into a motorized water pump 462 connected to the fresh water intake port 464 of a fresh water supply. A collar 466 is fixedly mounted to an intermediate section of shaft 445 located inside upper subchamber 202A (402A). Three horizontally extending radially equidistant hollow carrier tubular arms 468, 470, 472 radially project transversely from and are integral to shaft collar 466, each arm 468, 470, 472 supporting at its radially outwardmost end an eductor 450, 452, or 454 respectively. Main water line 460 branches out into fluid lines 468A, 470A, 472A inside the hollow of corresponding tubular arms 468, 470, 472, respectively.
[0061] As best shown in FIGS. 10 and 11, each eductor 450, 452, 454 defines a main body 450A having a fresh water supply intake port 450B, coupled to a corresponding radial arm fresh water supply flow line 468A, and an outlet port 450C coupled to an enlarged outflow nozzle 450D. Nozzle 450D defines an enlarged end mouth 451 opposite eductor main body 450A and opening into upper subchamber 402A. Additional fluid intake ports 450E and 450F may be provided to allow ambient liquid matrix from inside subchamber 402A to engage into the flowstream along fluid flows F10 and F11, directly through eductor hollow main body 450A and beyond nozzle 450 through nozzle end mouth 451 and into subchamber 402A along fluid flow F12. In FIG. 11, fluid flows F12 expelled from “reverse type” eductor nozzle 450D through nozzle mouth 451 strike head on in counter current fashion against incoming upstream waste water fluid flows F13 rotating clockwise inside upper subchamber 402A, and form counter-current fluid flows C1 and C2. Accordingly, Eddy type turbulence areas E1, E2, E3 are formed downstream of the reverse flow eductor 450 being generated from dynamic fluid interaction between fluid flows C1 and C2 and fluid flow F13, so as to promote fine particle separation (eg. in the 100 to 150 micrometer diameter range) from organic material.
[0062] It has been found that unexpected improved efficiency in grit removal capability relative to prior art grit removal apparatuses, can be obtained with such a grit removal apparatus of the present invention. The efficiency level relates to the difference in liquid matrix grit content in the influent channel, as compared to that in the grit-lite liquid matrix effluent channel. In one embodiment, the liquid matrix escaping from the present grit removal apparatus consists of a grit-less liquid matrix.
[0063] In FIG. 11A, “forward flow” eductor 550 expels fluid flows F14 in the general direction of incoming waste water fluid flows F15. As with FIG. 11, the fluid expelled along fluid flows comes from a mixture of both fresh water intake flow F16 connected to the shaft fluid line 445 and associated motorized water pump 462, and from fluid flows F17 and F18 through liquid matrix intake ports 550E and 550F of eductor main body 550A. Eddy turbulence areas E4, E5 are also formed downstream of forward flow eductor 550, promoting fine particle separation (e.g. in the 100 to 150 micrometer diameter range) from organic material.
[0064] The present grit removal apparatus is particularly well suited for wastewater treatment plants, but is not limited thereto.
