US 2018/0354835 A1Published application

Method and Apparatus for Increasing Dewatering Efficiency

OwnerF. Michael Lewisinventor

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Abstract

A method and apparatus for increasing dewatering efficiency of a solids-laden liquid stream in a wastewater treatment facility, whereby a liquids-solids stream is pumped into a mixing apparatus in a closed-channel liquid flow conduit configuration, where the liquids-solids stream is intensely mixed with air and polymer in a mixing zone created by an adjustable flow restriction device, performing similar to a venturi to increase the velocity, agitation, and turbulence of the liquids-solids stream internal to the mixer, where the introduction of air and polymer to the stream is introduced independent of mixing energy. Compared with current methods and apparatuses to mix polymer with solids-laden wastewater, the present method and apparatus requires less energy, where it enables the addition of air independent of mixing energy, and it creates a zone of mixing with greater mixing efficiency via increased turbulence.

Claims10

Dependent claims

An apparatus for mixing wastewater sludge with polymer and air to increase efficiency of dewatering process for wastewater treatment, comprising:

(a) a mixer housing having a closed-liquid flow conduit configuration;
(b) a housing inlet at one end of said housing and fluid flow passage;
(c) a housing outlet at opposed axial ends of said housing and fluid flow passage;
(d) a fluid flow passage for a sludge stream to flow through said mixer housing from the housing inlet to the housing outlet;
(e) a rotating axis, said rotating axis traversing the opposed internal walls of the mixer housing at pivot points on the internal walls,
(f) a flow restriction device internal to mixer housing and mounted to said rotating axis;
(g) a controller means controllably engaged to flow restriction device, to control positioning of flow restriction device;
(h) an air plenum, radially connected to said mixer;
(i) an air inlet;
(j) an air conduit fixedly attached to air inlet
(k) a bubble infusion means fixedly attached to air conduit;
(l) an air pumping means for introducing the air, through the air inlet, through air conduit, and through said bubble infusion means, into the fluid flow passage;
(m) said bubble infusion means provided upstream of said throttled section;
(n) a plurality of polymer inlets circumferentially placed around said mixer, upstream of said bubble infusion means,
(o) a polymer conduit axially connected to said polymer inlets;
(p) a polymer pumping means for introducing polymer through the polymer inlet, and through the said conduit for polymer, into fluid flow passage;
(q) a zone of intense mixing for mixture of sludge-polymer-air, said zone immediately downstream of interface between the fluid flow passage and the bubble infusion means;
(r) a throat, said throat comprising an opening for sludge flow travel along the longitudinal axis of said mixer housing immediately downstream of zone of intense mixing, said throat having a cross-sectional area less than cross-sectional area of said housing inlet, said throat having a cross-sectional area less than cross-sectional area of said housing outlet;
(s) Conduit means connecting said throat to said housing inlet;
(t) Conduit means connecting said throat to said housing outlet, said conduit means having a width that increases in a divergent manner as it moves axially from said throat to said mixer housing outlet;
(u) Pressure gauge means to measure pressure of sludge mixture inside housing,

18 more elements

A method for increasing the efficiency of the dewatering of sludge in wastewater treatment, by increasing the mixing efficiency of polymer, sludge, and air, including the steps of

(a) Providing an in-line mixing apparatus to a sludge flow stream, said mixer comprising (1) a mixer housing having an inlet and an outlet at opposed axial ends, said housing having a closed-channel liquid flow conduit configuration for sludge to flow from housing inlet to housing outlet, (2) an adjustable flow restriction device internally mounted to mixer housing, (3) a controller controllably attached to said restriction device, (4) an air inlet radially connected to housing, (5) a bubble infusion mean to introduce air bubbles into sludge stream downstream of flow restriction device, (6) an air pumping means fixedly attached to a bubble infusion means to introduce the air, through the air inlet, and through said bubble infusion means, into the sludge flow, (7) a plurality of polymer inlets, (8) a polymer conduit axially connected to said polymer inlets, (9) a polymer pumping means for introducing polymer through the polymer inlet, and through the said polymer conduit, into fluid flow passage;
(b) Adding polymer to said sludge stream at said in-line mixing apparatus;
(c) Adding air to said sludge stream downstream of the polymer addition at said in-line mixing apparatus;
(d) Adding polymer and air into the sludge stream, independent of mixing energy, over changes in flow rate up to 33%, by adjustably controlling the speed of the sludge flow through the in-line mixer, during changes in the rate of sludge flow through the in-line mixer, by adjustably restricting the sludge flow with said flow restriction device;
(e) Shearing air bubbles into sludge stream with the force of the perpendicular velocity of the sludge flow stream flowing perpendicular to the introduction of air into the sludge flow stream;
(f) Creating highly charged air bubbles to aid the charge-driven activity of floc formation in dewatering, through the interaction of bubbles colliding with one another in the sludge flow after shearing.

3 more elements

A method for increasing the efficiency of the dewatering of sludge in wastewater treatment, by increasing the mixing efficiency of polymer, sludge, and air, including the steps of

(a) Providing an in-line mixing apparatus to a sludge flow stream, said mixer comprising (1) a mixer housing having a closed-liquid flow conduit configuration;
(2) a housing inlet at one end of said housing and fluid flow passage;
(3) a housing outlet at opposed axial ends of said housing and fluid flow passage;
(4) a fluid flow passage for a sludge stream to flow through said mixer housing from the housing inlet to the housing outlet;
(5) a rotating axis, said rotating axis traversing the opposed internal walls of the mixer housing at pivot points on the internal walls, (6) a flow restriction device internal to mixer housing and mounted to said rotating axis;
(7) a controller means controllably engaged to flow restriction device, to control positioning of flow restriction device;
(8) an air plenum, radially connected to said mixer;
(9) an air inlet;
(10) a bubble infusion means;
(11) an air pumping means for introducing the air, through the air inlet, and through said bubble infusion means, into the fluid flow passage;
(12) said air inlet means fixedly attached to bubble infusion means;
(13) said bubble infusion means provided upstream of said throttled section;
(14) a plurality of polymer inlets circumferentially placed around said mixer, upstream of said bubble infusion means;
(15) a polymer conduit axially connected to said polymer inlets;
(16) a polymer pumping means for introducing polymer through the polymer inlet, and through the said conduit for polymer, into fluid flow passage;
(17) a zone of intense mixing for mixture of sludge-polymer-air, said zone immediately downstream of interface between the fluid flow passage and the bubble infusion means;
(18) a throat, said throat comprising an opening for sludge flow travel along the longitudinal axis of said mixer housing immediately downstream of zone of intense mixing, said throat having a cross-sectional area less than cross-sectional area of said housing inlet, said throat having a cross-sectional area less than cross-sectional area of said housing outlet;
(19) conduit means connecting said throat to said housing inlet;
(20) conduit means connecting said throat to said housing outlet, said conduit means having a width that increases in a divergent manner as it moves axially from said throat to said mixer housing outlet;
(21) pressure gauge means to measure pressure of sludge mixture inside housing;
(b) Adding polymer to said sludge stream upstream of flow restriction device at said in-line mixing apparatus;
(c) Adding air to said sludge stream downstream of the polymer addition at said in-line mixing apparatus;
(d) Adding polymer and air into the sludge stream, independent of mixing energy, over changes in flow rate up to 33%, by adjustably controlling the speed of the sludge flow through the in-line mixer, during changes in the rate of sludge flow through the in-line mixer, by adjustably restricting the sludge flow with said flow restriction device;
(e) Shearing air bubbles into sludge stream with the force of the perpendicular velocity of the sludge flow stream flowing perpendicular to the introduction of air into the sludge flow stream;
(f) Creating highly charged air bubbles to aid the charge-driven activity of floc formation in dewatering, through the interaction of bubbles colliding with one another in the sludge flow after shearing.

22 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/820,440Filed 22 Nov 2017
Priority: 9 Jan 2017
Published: 13 Dec 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification12 codes

C02F 11/147
With addition of chemical agents: using organic substances
B01F 23/2311
Arrangement or manipulation of the gas bubbling devices: mounting the bubbling devices or the diffusers
B01F 23/2323
Using flow-mixing means for introducing the gases, e.g. baffles: by circulating the flow in guiding constructions or conduits
B01F 25/103
Mixing by creating a vortex flow, e.g. by tangential introduction of flow components: with additional mixing means other than vortex mixers, e.g.…