[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit ofU.S. Provisional Patent Application: No.

62/444,012, filed January 9, 2017 by the present inventor

[0003] FEDERALLY SPONSORED RESEARCH

None.

SEQUENCE LISTING

[0006] None.

[0007] INVENTOR

[0008] F. Michael Lewis

[0600] BACKGROUND - PRIOR ART

The following is a tabulation of some prior art that presently appears relevant:

US 3,334,868 11/1062 Lage

U.S, Patent Application Publications

Publication Number PubL Date Assignee

US 2013/0220937 A1 8/2013

Nonpatent Literature Documents

Takagi, Shu, and Mat&umoto, Y., Annual Revie w of Fluid Mechanics, VoL 43,

“Surfactant Effect on Multiseale Structure of Bubbly Flows" (2011), pp.615-636. Takahashi, Masayoshi, Journal of Physical Chemistry, *The Zeta Potential of

Microbubbles in Aqueous Solutions,” (November 2005).

Takahashi, Masayoshi, National Institute of Advanced industrial Science and Technology - Japan,“The Fantastic Properties of Microbubbles,” (undated)

Cho, H. Jeremy, MSzerak, Jordan P. and Wang, Evelyn N., Nature Communications, “Turning bubbles on and off during boiling using charged surfactants,” (October 21, 2015).

[00010] BACKGROUND

[00011] Sludge is the semi-liquid residual material left from wastewater treatment

processes, and consists of water and suspended particle pollutants such as

microorganisms, mineral matter, and other particles.

[00012] It has been achallenge for Waste Water Treatment Plants (WWTP) to treat and dispose of tiie increasing volumes of sludge, as the communities WWTPs serve are growing. Additionally, WWTPs adherence to restrictive environmental repletions plays a central role in pushing the seed for effective and efficient sludge removal efforts.

[00013] Sludge removal efforts and the effectiveness and efficiency thereof can be greatly influenced by the effectiveness and efficiency at which water is removed from the sludge, where disposal fees are directly proportional to the weight of tiie sludge being removed. The weight of the water entrenched in the sludge makes up a majority of the weight of the sludge. It is therefore highly desirable to extract as much water ftom the sludge as possible. To extract the water from the sludge would greatly reduce sludge transport removal costs, and dtereby effectively enhance Sludge removal efforts by increasing its efficiency.

[00014] A method used to extract water from the sludge is the mixing of the aqueous Sludge solution with a polymer used to aid the aggregation of the particles within the aqueous sludge solution, to thereby separate the particles from the water, enabling the water to be extracted from tile aqueous solution more efficiently. In wastewater treatment, tins method is part of the genetically named“dewatering” process. Generally, following the separation of the water and particles while within the aqueous sludge solution, a mechanical means for separation (e.g. centrifuges, belt presses), which are known to persons of ordinary skill in the art of dewatering for a wastewater treatment process, is soon implemented to mechanically extract the water from the remaining solid sludge particles. The instant invention will provide an apparatus and method that will increase the efficiency of this dewatering process, by providing an apparatus and method that will increase the efficiency of the mixing of polymers into the sludge— where mixing efficiency is directiy proportional to particle aggregation and wafer separation, and where fhe rate of air introduction and the mixing energy are independently variable.

[00015] In the aqueous sludge solution, many of the suspended particles have a negative surface charge and are surrounded by positive counter-ions, which cause the particles in the sludge to repel each other, in comport with the electrical forces of repulsion, In providing for an efficient dewatering process it is highly desirable for the suspended particles of this aqueous sludge stream to attract to one another and aggregate. To aid this process of particle aggregation, polymers are added to the aqueous sludge stream. Polymers are added to the aqueous sludge, and through adsorption— the adhesion of atoms, torn, or molecules from the polymers to the surface of the particle pollutants, where a film of the polymers is left on the surface of the particles— the particles sire enabled to overcome the electrical forces of repulsion, and become attracted to one another, in comport with Van der Waals forces. The effectiveness of the polymer addition to the sludge side-stream, to further the process of adsorption, increases the effectiveness of wastewater treatment, where it aids particle aggregation.

[00016] Rapid mixing is the process by which the polymer is rapidly dispersed throughout the aqueous sludge solution, where the particles are brought into contact with one another to form flops (through the process of flocculation), which enables the free water to be removed in dewatering. The rapid mixing stage is quite possibly the most important stage of the dewatering process, and drives fee effectiveness and efficiency of the dewatering process as a whole. The principal parameter governing the rate of flocculation is the velocity gradient applied to the sludge/polymer mixture. Velocity gradients can be induced by multiple means, readily known by those ordinarily skilled in the art of pipe liquid flow and ahr/fiquid contact is pipe, such as through fee use of a venturi (known in function to be a constricted area of a pipe, narrowed to effect a pressure and velocity change iiithefluid traveling through fee narrowed section). The instant invention will induce a velocity gradient change through a mechanical means (hereinafter also described as a flow restriction device), such as a venturi, to increase miring efficiency.

[00017] Additionally, where turbulence is created, a pressure gradient effect is also

anticipated. Where fee infusion of air and polymer into an aqueous sludge solution occurs and creates an increase m tufbtience, then a pressure gradient change will also be exhibited, and mixing will be aided. The instant invention. will aid in increasing fee pressure gradients thmughthe novel infusing of air and polymer into fee area of the pipe directly downstream of venturi-induced gradient change. The said mixing zone will hereinafter be called fee zone of intense mixing,

[00018] It is highly desirable to increase fee efficiency of tile dewatering process- intended to increase its total solids (T.S.) content Even small dewatering efficiency improvements (1% T,S, - 2% T.S,) will have a significant impact on improving overall disposal economics. Unfortunately, increases in fee efficiency of dewatering occur wife increases in mixing energy or increases in polymer doring, which are accompanied by undesirable increases in operational costs. The desirableness of efficiency improvement methods, such as increasing miring energy or polymer dosing, is thereby mitigated by their cost-prohibitive nature, which makes fee necessity of an economical apparatus and method for increasing dewatering efficiency readily apparent, which is satisfied wife fee present method and apparatus. [00019] SOMMARY OF TOE INVENTION

[00020] The instant method and apparatus is for improving dewatering efficiency in the field of wastewater treatment, and more specifically in the field of polymer addition to a sludge stream (i.e. a dilute phase biosolids stream) for aiding floe formation and water removal, where a user may introduce air and coagulant into the sludge stream, independent of mixing energy, and where a user may create a zone of intense mixing for the dilute phase biosolids-air-polymer stream. The present and novel method for improving dewatering efficiency comprises the addition of air and polymer to a sludge stream, where the bubbles are infused through an in-stream bubble in&sion device (also called a sparger) into the sludge stream at a location along the sludge stream immediately downstream of the polymer addition and immediately downstream of the mechanical means to induce a velocity gradient change in the sludge stream, which will be done through the use of an adjustable flow reaction device. The bubbles are introduced to the sludge stream at an angle perpendicular to the sludge flow streamlines at the interface of the air outlet orifice and the sludge stream. Where the sludge flowrate is increased, in combination with the effect of the added polymer and the added air into the sludge stream, a zone of turbulent and intense mixing of the components in the stream occurs, and mixing will therefore be enhanced.

[00021] The introduction of the air intothe sludge-polymer stream at an angle

perpendicular to the sludge streamline at the interface of the air outlet and the sludge stream promotes the sheering of air bubbles into the sludge-polymer stream by the increased perpendicular velocity of the sludge-polymer stream— prompted by die velocity gradient increase of the sludge-polymer stream as it passes through the flow restriction device— where the sheering creates bubbles of the infused air with diameters of lengths shorter than what ordinarily occurs during tire infusion of air into a sludge stream flowing under typical flow, or static flow patterns of sludge flowing within a pipe, where the sludge flow rate has not been increased by an adjustable flow restriction device immediately upstream,

[00022] The present novel method and apparatus will create a zone of intense mixing at an intensity higher than that which occurs in typical pipe sludge flo w;, where polymer and air are introduced to a sludge-filled pipe of the dewatering process. The zone of intense mixing will be generated by and defined as the induced increase in tile sludge flow rate (i.e. velocity gradient)— caused by the adjustable flow restriction device and throat that constricts the cross-sectional flow area of the incoming sludge mid polymen— in combination with the turbulence generated by the infusion of air bubbles into the same stream at the throat of the apparatus, immediately downstream ofthe adjustable flow restriction device. Additionally, the zone of intense mixing will effectively mix the polymer— which will have been added to the sludge immediately upstream of the adjustable flow restriction device— into the dilute phase biosolids stream.

[00023] Also, (he rate of air introduction and mixing energy will be independently

variable, where here, the flow restriction device will employ a control means for a setpoint pressure drop known to those of ordinary skill in the arts of fluid flow within pipe, to keep the pressure drop relatively constant over anticipated changes in the siudge flowrate of a dewatering process in. a wastewater system. Where the pressure drop remains constant, the mixing energy will also remain essentially constant A control means may be a counter-weighted aim, external to the pipe, that mechanically controls the position of an internal pipe flow restriction device, performing in unison, analogous to the unified movements of a pipe valve and its external valve position control means.

[00024] The apparatus can comprise a pipe or other closed-channel liquid flow conduit with a liquid inlet and liquid outlet at opposed axial ends, having an air plenum radially connected, having an air conduit connected to the air plenum, an air inlet, a bubble infusion device fie. sparger), an air outlet where an air outlet is fixedly attached to a sparger, a polymer inlet, where a polymer inlet may be a polymer injection port a liquid conduit axially connected to the polymer inlet, and an air-liquid outlet, a flow restriction device internally mounted within the pipe or other closed-channel liquid flow conduit

[00025] A polymer inlet may be in multiple, with multiple ports to deliver polymer at multiple locations into the sludge flow stream, and is immediately upstream of the flow restriction device. Where in multiple, the polymer inlets may be positioned and deliver polymer at multiple locations circumferentially around the pipe or other closed-channel liquid flow conduit, to aid uniform distribution of the polymer, to ultimately aid mixing of the polymer within the sludge flow stream. [00026] The flew restriction device may have its physical position within the pipe or conduit controlled by a mechanical means to impede the flow direction and flow rate of the sludge stream within the pipe or conduit He flow restriction device is provided to control the pressure drop of the sludge stream within the pipe or conduit and to increase the velocity of the sludge stream and mixing energy within the pipe or condtat; analogous to the effect of a venturi.

[00027] The flow restriction device will function as a converging section of the pipe, and may be adjusted by its rotation along the aids of its pivot point; which may rotate the flow restriction device within a range of positions that either impedes the cross-sectional flow areaof the incoming sludge within the pipe or facilitates unimpeded cross-sectional flow of the incoming sludge. The flow restriction device is fixedly mid radially attached to the axis located at the pivot point The flow restriction device has a width in the horizontal plane that: may extend to the width of the apparatus, from the left ride wall to the right side wall. The flow restriction device is a height in the vertical plan, when rotated vertically down into the pipe or conduit, and further into the cross-sectional flow of the sludge* that may extend from the top to toe bottom of the apparatus, to impede toe cross- sectional flow of toe sludge. The flow restriction device will Induce an increase in toe velocity of sludge flow to a maimer analogous to a venturi, where a converging section of a pipe increases the velocity of the contents flowing to the pipe and a corresponding pressure drop.

[00028] The flow restriction device is fixedly attached to the sparger. The sparger and toe piyot point are at diametrically opposed ends of the flow restriction device. The sparger emits toe air into the sludge stream, where the air is introduced Into the sludge stream as bubbles. The sparger is immediately upstream of toe throat the flow restriction device rotates along its pivot point to raise and lower the sparger inside toe conduit or pipe.

[00029] The rotating axis of toe pivot point of toe flow restriction device may traverse the inside of the pipe or closed-channel conduit, from toe left-side wall to toe right-side wall, through the boundary walls of the pipe or closed-channel liquid flow conduit, and engage a cdunterweighted atm that will be radially connected to toe rotating axis of toe pivot point of the flow restriction device. The rotation of toe pivot point axis may be controlled by toe counterweighted arm* which may rotate circumferentially around toe axis of the pivot point, where the counter-weighted aim may be connected to the pivot point axis at a distance from the external wall of the pipe or closed-channel conduit that will allow unhindered rotation of the counterweighted arm and its counterweight around the axis of the pivot point

[00036] Accordingly, several advantages of the present invention ami apparatus are 1) to «reate a turbulent zone of mixing for polymer, air, and sludge to aid dewatering, and 2) to independently vary the rate of air introduction and mixing energy, and 3) to increase the production of babbies at diameters smaller than those introduced into a static liquid stream or stream flowing under typical wastewater flow conditions, by perpendieulariy introducing air into a high velocity sludge stream immediately downstream of polymer injection* to enable effective sheering of bobbles into the stream, and 4) to increase the solids content of the sludge stream while using less polymer than that traditionally needed for the same solid content, and 5) to save financial resources as a result of the decreased need for polymer.

[00031] DESCRIPTION

[00032] It is the purpose of Sis instant invention to define a process and illustrate m

apparatus that improves dewatering efficiency during mixing of the air ami liquid of Se system, by increasing the percentage of total solids in the biosolids and decreasing the percentage of water content, of by decreasing tire volume of polymer dosing to the biosolids stream* or by decreasing the energy used to mix the dil ute phase of biosolids with polymer,

[0003:3] The instant method and apparatus for increasing tile efficiency of tile dewatering process delivers air and polymer to the aqueous sludge solution in a manner conventional to air-liquid mixing systems. A myriad of air inducing means may be utilized to infuse air into the aqueous sludge solution, where the means must entrain the air or compress the air to a pressure equal to or greater titan the static head at the desired liquid depth.

[00034] The apparatus can compromise a pipe or other closed-channel liquid flow conduit with a liquid inlet and liquid outlet at opposed axial ends, haying an ait plenum radially connected, having an air conduit connected to the air plenum, an air inlet, a polymer inlet, where a polymer inlet may be a polymer injection port, a Hquid conduit axially connected td polymer injection port, a liquid inlet, and an air-liquid outlet, a flew restriction device internally mounted within the pipe or other closed-channel liquid flow conduit, a flow restriction device controller controliably attached to the flow restriction device. The air plenum will he comprised of separate space cavity fin air to aggregate and from which tiie infusion of the air into the aqueous stream will occur. The air space will be of a dimension where an air conduit may traverse its cavity without restriction. The air plenum space cavity may be a solid hollow structure, or a hollow cavity made from a multiple walls fastened together by a fastening means, such as a nut and bolt

[00035] The aqueous sludge stream will flow horn the sludge flow inlet of the apparatus, past the flow restriction device, past the sparger, and out the sludge flow outlet Polymer may be introduced into the aqueous sludge stream within the pipe or other closed-channel liquid flow conduit, by various polymer pumping devices known to those ordinarily skilled in the arts, through polymer injection ports drcumfeientially located in the perimeter wall of the pipe or other closed-channel liquid flow conduit, where the polymer may be discharged from the ports to the internal space of the channel. According to a preferred but optimal feature of the invention* the ports am shaped as nozzles directed: toward the axis of Sow of the sludge stream.

[00036] The air conduit can be comprised of a flexible hose, that may allow for

unimpeded flow of air through the conduit into the air plenum, and that may not have an effect on tite position of the flow restiictian component, winch can be comprised of a flow restrictor plate, Or valve, or that known by a person of ordinary skill in the arts of liquid and air flow within a pipe or in the field of dewatering or wastewater treatment to restrict the flow of the liquid in the pipe or other closed-channel liquid flow conduit.

[00037] Ttte air can be entrained into the liquid through the air inlet by various air

pumping devices known to those ordinarily Skilled in the arts, at an angle perpendicular to the axial flow of the liquid, which aids in increasing the turbulence in the pipe or other closed-channel liquid flow conduit, due to the effect of the velocity gradient being applied to the liquid flow through the pipe or other closed-channel liquid flow conduit

[00038] The air inlet may be radially connected to the pipe or other closed-channel liquid flow conduit, perpendicular to the axial plane of the pipe or other closed-channel liquid flow conduit [00039] The air will be introduced into the liquid stream at a pressure greater than or equal to a pressure required to overcome any opposing forces of the liquid stream that will prevent the intrusion of the air into the liquid stream. The air will be introduced in the liquid stream at a pressure greater than or equal to a pressure required to allow for intrusion of the air into the portion of the pipe or other closed-channel liquid flow conduit at a location at least along the internal wall of the pipe or other closed-channel liquid flow conduit, containing the liquid stream _* to a distance radially inward from the internal wall into the liquid stream. The density of the aerated water at the outlet of the apparatus will be less than the density of water.

[00040] The air will be introduced into the; liquid stream at a distance along the axial plane of the pipe or other closed-channel liquid flow conduit, where the velocity gradient created by the pressure drop has maximized.

[00041] The air introduced into the liquid stream can be introduced through an orifice of a diameter less than that of the diameter of the pipe or other closed-channel liquid flow conduit The air introduced into the liquid stream can be introduced into the liquid stream at a constant flow or at intermittent patterns through the orifice.

[00042] It ¼ a feature of the instant method and apparatus that the perpendicular velocity of the liquid stream will effectively shear air being introduced to the liquid stream into air bubbles with diameters less than the diameters of bubbles from air being introduced into a static liquid stream. It is rise a feature of the instant method and apparatus feat fee perpendicular velocity of the liquid stream wifi sheer the air bubbles more effectively where air is being introd uced into a liquid stream at a location along the axial flow of fee liquid stream where mixing energy is maximized by the increased perpendicular velocity maximized by an internal flow restriction device, than at another location. The ait bubbles being sheared into fee liquid stream at the turbulent zone may continue for approximately 4-10 pipe diameters downstream in what is termed“bubbly flow ¹ * (also btown as“bubbly swarm”),

[00043] Associated with bubbly flow (aka bubbly swarm) are complex interactions

between fee bubble interfaces and also between the bubbles and fee liquid, such as bubbles interacting with one another through collisions or fee effects of wakes caused by the bubbles. The phenomenon is explained by fee Marangoni effect, which can be seen by bubbles in liquid presenting surfactants, such as contaminated water. Where surfactants are present in water, bubbles experience a surface concentration distribution along the bubble surface, which accumulates in the rear part of the bubble as itrises, Which caws a tangential sheer stress on the bubble surface, resulting in the decrease in the rising velocity of a bubble contaminated water. In some cases, the bubble can become so contaminated that its rising velocity equals the same drag coefficient of a rigid particle is reached, and will behave like a rigid particle in water. Additionally, electric charges are created by the formation and interactions of these“bubbly flow” bubbles, which further aids the charge-driven activity of floe fo n, thereby increasing tire effectiveness of the present method and apparatus.

[00044] The aqueous biosolids stream will flow in a pipe or other closed-channel liquid flow conduit, Where the flow in the pipe or other closed-channel liquid flow conduit is capable of being restricted in a particular section by a restriction device, that can be comprised of a restrictor plate or restricting valve, which can induce a pressure change and velocity change in the flted flowing from the sludge flow inlet to the sludge flow outlet. The flow restriction device may be capable of autonomous control.

[00045] Another feature Of the self-contained apparatus and method for increasing the efficiency of dewatering by mixing air and liquid in a high turbulence region within a pipe or other closed-channel liquid flow conduit, is its ability to scale to any size with current technology and materials, whether a small dewatering process that treats less than 5 million gallons per day, or whether a large dewatering process teat treats more than 100 million gallons per day,

[00046] Another feature of the apparatus and method for increasing the efficiency of a dewatering process by mixing air and liquid m a high turbulence region within a pipe or other closed-channel liquid flow conduit, is its ability to oppose a leading liquid flow with a flow restriction device, which can be comprised of an adjustable restrictor plate, rotatably connected tothe interna! perimeter of tire pipe or confined space, to direct the angle of liquid flow in a direction to flatten or optimize the shape of the liquid medium, to add velocity to the liquid medium. The flow restriction device wifi reduce the liquid cross sectional flow area, thereby i g the turbulence in this zone of intense mixing. [00047] Another feature of the apparatus and method for increasing the efficiency of a dewatering process by mixing air and liquid in a high turbulence region within a pipe or Other closed-channel liquid flow conduit is its ability to vary the efficiency, pressure, or velocity, of intake of air iii fee liquid medium.

[00048] Another feature ofthe apparatus and method for increasing the efficiency of a dewatering process by mixing ah' and liquid in a high turbulence region within a pipe or other closed-channel liquid flow conduit is its ability to pump very large volumes of liquid medium throughthe mixing region while using much less energy dr power than conventional processes and apparatuses that aid in dewatering.

[60049] Another feature ofthe apparatus and method for increasingthe efficiency of a dewatering process by mixing air and liquid in a high turbulence region within a pipe or other closed-channel liquid flow conduit is its abEty to intake liquid medium at a depth or strafe (level) of the liquid medium and discharge liquid medium at a depth or strafe of the liquid medium resulting in the ability to mix horizontal l¾rers or strata of the liquid medium.

[00056] Another feature ofthe apparatus and method for increasing the efficiency of a dewatering process by mixing air and liquid in a high turbulence region within a pipe or Other closed-channel liquid flow conduit is its ability to enable inlet air to be acquired at one strata (level) and discharge at an outlet water-air mixture to be released or discharged at another strata.

[00051] The flow restriction device controller can be comprised of a counter-weighted arm, rotatably connected to fee flow restrictor device, and may be controlled through a counter- weighted arm. Other liquid pipe flow restriction control devices may be used, which are ordinarily known by a person of reasonable and ordinary skill in theart of liquid-air pipe flow controls,

[00052] A principal object of this instant invention is to allow for air id be introduced into the aqueous sludge stream at a rate independently variable fromthe mixing energy, enabled by a mechanical means to control a pressure drop inthe liquid channel at rates where aqueous sludge stream flow rates change by no more than 33 percent To a person or ordinary idsill in the art of liquid air mixing, there are: multiple mechanical controller means to meet fee object of pressure control to maintain a desired pressure drop of the aqueous sludge over a range of sludge flows at flow rates that change by no more than 33 percent.

[00053] Specifically, a means to meet the object of pressure control to maintain a desired pressure drop can be accomplished through the use of a coimterweighted arm that is rotatably connected to a flow restriction device that will control a pressure drop in the liquid channel A means for gauging pressure is an object of this instant invention, which may be accomplished by a pressure gauge means at locations both upstream and downstream of the flow restriction device.

[00054] A principal object of tiiis instant method and apparatus to increase dewatering efficiency will add polymer to the sludge stream occurring at a location along the axial flow direction of the aqueous sludge stream, at a radially connected location in the immediate vicinity upstream of the zone of intense mixing, occurring within the pipe or other closed-channel liquid flow conduit.

[00055] The invention has been described in an illustrative manner* and it is to be

understood that the terminology which has beat used is intended to be in the nature of words of description rather than of imitation. Obviously, many modifications and variations of the present method and apparatus are possible in light of the above teachings. For example, the flow restriction device, internally attached to the pipe or conduit can be either a flow restrictor plate Or valve. Additionally, the nozzle from which air is delivered into the sludge flow can be either a nozzle or a porous aeration stone, or a piece of metal screening. It is therefore, to be understood that within the scope of the above description, the invention may be practiced otherwise than as specifically described.

[00056] DRAWINGS

[00057] FIG. 1 is a perspective right-side view of the apparatus, constructed in accordance with the invention.

[00058] The presently preferred embodiment of the apparatus herein to increase

dewatering efficiency, according to the invention is shown in FIG. 1.

[00050] FIG.2 is ft perspective left-side view of the apparatus.

[00060] FIG, 3 is a plan view of the apparatus.

[00061] FIG. 4 fe a right-side view of tiie apparatus. [00062] FIG. 5 is a longitudinal section view of the apparatus from the right side of the apparatus.

[00063] FIG.6 is a longitudinal section view of the apparatus from the left side of

apparatus.

[00064] FIG. 7 is a longitudidal section view ofthe apparatiis from undemeaihthe

apparatus.

[00065] FIG.8 is a longitudinal section view of the apparatus from the right side of the apparatus where the flow restriction device and sparger have been controllably rotated by the counter-weighted arm to a position a distance“A” above the bottom of the apparatus.

[00066] FIG.9 is a longitudinal section view of the apparatus from the right side of the apparatus where the flow restriction device mid sparger have been controllably rotated by the counter-weighted arm to a position a distance“B* abo ve the bottom of the apparatus.

[00067] FIG. 8 and FIG.9, in contrast, showcase the movement of the flow restriction device and sparger, as a function of the movement of a means to control their movement (i.e. counter-weighted arm).

[00068] DRAWING REFERENCE NUMERALS

[00069] DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[00070] A method and apparatus to increase the efficiency of downstream dewatering in wastewater treatment through a cost-effective increase in the mixing efficiency of a sludge-polymer-air aqueous stream according to a preferred embodiment of the present invention will now be described; with reference to FIGS. 1-9. [00071] Referring now to FIG. I of the drawings, the apparatus 11 wilt receive the influent sludge 1 stream through its sludge flow inlet 19 a! the front of the apparatus 15, and may pass through the Apparatus 11 to the back of the apparatus 23* along the longitudinal axis 16, so that fee sludge flow may be mixed wife air from an air source 3 and polymer from a polymer source 4 in the zone of intense mixing 50,

[00072] Referring now to FIG.2 of the drawings, the apparatus discharges its sludge- polymer-air stream 2 through its sludge flow outlet 24 at the hack of the apparatus 23, after passing through the apparatus 11 along the longitudinal ads 16, where the sludge 1 will have mixed with air and polymer in the zone of intense mixing. An air inlet 20 is seen near the top of the apparatus 12, where air will be provided from an air source 3 by a means to produce air, such as a compression pumping device-, to be delivered to an air conduit 53 within an air plenum 56, that will affect the transport of the air into the flow of sludge 1 through the apparatus. The walk of the air plenum may be fastened together v,ith a fastening means 25. Pressure will be gauged with a pressure gauge means 26.

[00073] Referring now to FIG; 3 of the drawings, a plan view of the apparatus H shows a counter-weighted arm 14 radially connect to the axis of the pivot point for the flow restriction device 21. The counter-weighted arm 14 circumferentially rotates about the axis of the pivot point for the flow* restriction device 21, and controls the circumferential rotation of the pivot point axis. The counter-weighted arm is on the left side of the apparatus 22, but alternative embodiments cold relocate the counter-weighted arm 14 to another location around the apparatus 11. A plurality of mechanical control technologies to a personal of ordinary skill in the art of pipe flow control could be used in place of a counter-weighted arm 14.

[00074] Referring now to FIG.4 of the drawings, the apparatus 11 is show from its right side 13, showcasing the external wall of the air plenum 57 that houses the air conduit 53, which received air from an air source 3 to the air inlet 20.

[00075] Referring now to FIG. 5 of the drawings, the flow restriction device 51 is radially and rotatably attached to the pi vot point for the flow restriction device 21, winch is controlled via circumferentiai movement of fee counter-weighted arm 14 about the pivot point for the flow restriction device 21. The direction of flow of fee sludge 1 travels from fee front of fee apparatus 15 through fee sludge flow inlet 19, past the sludge flow restriction device 51, through the throat 58 and zone of intense mixing 50. The zone of intense mixing 56 is created by fee high turbulence in fee sludge flow immediately downstream of the flow restriction device 51, where air is being introduced from an air source 3 into the sludge stream through an air introduction orifice 52. The sludge flows at a velocity high enough that shears the air being: introduced perpendicular to fee sludge stream through the air introduction orifice 52, within fee throat 58. The air bubbles 54 created by fee shearing effect of fee sludge velocity may continue for approximately 4-10 pipe diameters downstream in“bubbly flow."

[00076] FIG. 6 is identical to FIG, 5, but rotated 180 degrees about the vertical axis 17 of the apparatus 11, as shown in FIG. 1.

[00077] Referring now to FIG. 7 of the drawings, the ^; air introduction orifice 52 can be seen nearly midway along fee longitudinal axis 16 of the apparatus 11, and introduces air into the flow of sludge 1 immediately downstream of fee flow restriction device 51 at fee throat 58, creating a zone of intense mixing 50, where there ape small-diameter air bubbles 54 created at fee location of air bubble shearing 55. The sludge flow 1 continues along fee direction of the longitudinal aids 16 toward fee back of the apparatus 23, before exiting at the sludge flow outlet 24,

[00078] Referring now to FIG. 8 of fee drawings, fee flow restriction device 51, fixedly attached to fee sparger 59, is rotated circumferentially around the pivot point 21 of the flow restriction device 51 to height "A* ^* 80 from the bottom of fee apparatus 40, where fee height of fee flow restriction device SI and the sparger 59 is controlled by the counter-weighted arm 14 radially connected to the pivot point 21 of the flow restriction device 51, which is positioned a distance“X” 81 from the top of fee apparatus 12.

[00079] Referring now to FIG.9 of fee drawings, fee flow restriction device SI, fixedly attached to fee sparger $9, is rotated circumferentially around the pivot point 21 of fee flow restriction device 51 to a height "B" 90 from the bottom of the apparatus 40, where the height of the flow restriction device 51 and the sparger 59 to controlled by the counter-weighted arm 14 radially connected to the pivot point 21 of the flow restriction device 51, which is positioned a distance“TP" 91 ftom the top of the apparatus 12, The difference between height“A” 80 of FIG. 8 and height“B” 96 of FIG. 9, correspond to tile difference between the distance“X” 81 of FIG. 8 and distance“Y” 91 of FIG. 9 of the controlling counter-weighted arm 14. Height“A" 80 is not equal to height“B” 90.

Distance“X” 81 is not equal to distance *Y 91.

[00080] From tbe description above, a number of advantages of some embodiment of the method and apparatus 11 for increasing dewatering efficiency become evident; a. A zone of intense mixing and high turbulence is created by reducing the liquid cross sectional Sow area of the sludge stream with the adjustable flow restriction device 21,

b. The zone of intense 5® mixing and high turbulence efficiently mixes the air 3 and polymer 4 into the biosolids stream.

c. The adjustable flow restriction device 51 enables the introduction of air 5 and polymer 4 into the biosolids stream independent of mixing energy, by maintaining a constant pressure drop in ti$e sludge 1 flowing through the apparatus 11.

d. The perpendicular velocity of the sludge stream in the pipe, immediately

downstream of the flow restriction device 51, effectively creates tiny bubbles 54 of air at the zone of intense maxing 50 by sheering tiny bubbles 54 into the sludge stream, which also increases mixing efficiency.