WO2003020391A1

WO2003020391A1 - Polymer feed system

Info

Publication number: WO2003020391A1
Application number: PCT/US2002/027583
Authority: WO
Inventors: James E. Thompson; Yongming Xia
Original assignee: Ashbrook Corporation
Priority date: 2001-08-31
Filing date: 2002-08-30
Publication date: 2003-03-13

Abstract

A polymer injection and feed system includes a mixer body (32) adapted to allow an aqueous stream to flow through an internal cavity (58) of the mixer body (32). A restriction point is defined by a trailing end of a gate (46) and a top portion of the internal cavity (58) of the mixer body (32). A single polymer feed line (38) communicates with the internal cavity (58) near the restriction point, wherein the restriction point is adapted to provide turbulent mixing of a polymer with the aqueous stream, without premature flocculation. A method of polymer injection is also disclosed.

Description

POLYMER FEED SYSTEM BACKGROUND OF THE INVENTION

1. Field of the nvention

[0001] The present invention relates to a method and apparatus for applying or adding materials to aqueous systems. Specifically, the present invention relates to a method and apparatus for applying or feeding polymers to aqueous streams, such as waste water streams.

2. Description of the Prior Art

[0002] When applying a water-soluble or water-dispersible "liquid" polymer to an aqueous system, compact molecules are uncoiled and extended so that they can perform their intended task. Applications requiring such polymers include the purification of water, the fiocculation and dewatering of sludge, the separation of mined materials from water, and paper manufacture. Generally, liquid polymer is available in two forms: water-in-oil emulsion polymers and aqueous solution polymers. Water-in-oil emulsion polymers are more expensive but also, generally, more effective. Solution polymers, on the other hand, have been used for many years and are preferred by many because of their low cost.

[0003] The treatment polymers are typically "activated" prior to being fed to an aqueous stream to be treated. The activation step allows the tightly coiled, typically high molecular weight polymers to uncoil and fully extend. Once the polymer is activated, it is fed to the aqueous stream to be treated.

[0004] Conventionally, when treating waste water streams, the polymer needs to be injected such that it is equally distributed around a sludge flow pipe before it goes into a mixer. The mixer's function is to thoroughly co-mingle and encourage surface contact between the polymer and the sludge solids. In conventional designs, the polymer is injected at a point of relatively high pressure some distance from the mixing point. Typically, a number of polymer feed lines are applied at an injection ring to achieve equal distribution into the sludge. However, often times, there is not equal flow in each of the polymer feed lines.

[0005] As soon as the polymer enters the sludge stream, some of it reacts with the sludge and begins the fiocculation process (binding the solid particles in suspension into clumps or floes). This occurs while the sludge and polymer mixture is moving from the injection ring toward a mixing point. When the mixture, with some of the polymer already bound to solid particles in the sludge flow, hits the mixing point, the clumps or floes that have prematurely formed through fiocculation are destroyed, wasting that portion of the injected polymer. The unreacted polymer is then mixed with the sludge flow, and fiocculation begins anew, but the polymer that was bound to solid particles does not react to flocculate the sludge, resulting in wasted polymer.

[0006] There remains a need for a polymer injection and mixing system that can provide efficient application of treatment polymers with minimal losses due to premature fiocculation.

SUMMARY OF THE INVENTION

[0007] The present invention provides a polymer injection and feed system that minimizes losses due to premature fiocculation. The present polymer injection and feed system includes a single polymer feed line through which a polymer solution is injected directly into a mixer body near a restriction point, which provides turbulent mixing of the polymer with the solids of an aqueous stream.

[0008] The present invention is further directed to a method of applying a polymer to an aqueous stream using a polymer injection and feed system. The method involves passing an aqueous stream through an internal cavity of a mixer body, introducing a polymer to the aqueous stream providing a restriction point in the internal cavity at a single feed point in the internal cavity proximate and upstream of the restriction point, and mixing the polymer solution and the aqueous stream in a turbulent manner.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Fig. 1 is a front elevation view of a prior art polymer injection and feed system;

[0010] Fig. 2 is a front elevation view of a polymer injection and feed system of the present invention;

[0011] Fig. 3 is a cross section of a mixer body in the polymer injection and feed system of the present invention;

[0012] Fig. 4 is a front elevation of a polymer injection and feed system using a mix tank and eduction; and

[0013] Fig. 5 is a perspective view of a polymer injection and feed system using a mixing chamber.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] For the purpose of the description hereinafter, the terms "upper," "lower," "right," "left," "vertical," "horizontal," "top," "bottom," and derivatives thereof shall relate to the invention as oriented in the drawing Figures. However, it is to be understood that the invention may assume alternate variations and step sequences except where expressly specified to the contrary. It is also to be understood that the specific devices and processes, illustrated in the attached drawings and described in the following specification, are only exemplary embodiments of the invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting the invention.

[0015] As used herein, the term "polymer" is meant to encompass oligomers and includes without limitation both homopolymers and copolymers in dry, liquid, or gel form. The term "liquid" encompasses both water-in-oil and oil-in-water emulsions, suspensions of polymer particles in any continuous phase and solutions of polymers in any solvent, including but not limited to, water.

[0016] As used herein, the term "sludge" is meant to encompass solid, oily, and/or greasy material suspended, dispersed, or in any way present in an aqueous system. As such, the term "sludge" is meant to include, but not be limited to, the solids present in municipal waste, solid and water insoluble industrial wastes, such as cutting fluids, paint overspray, laundry wastes, and the like, coal fines and the like, fly ash and the like, and pulp and other solids used in paper manufacture.

[0017] As used herein, by "water-soluble polymer" what is meant is a polymer that has a solubility in distilled water of at least lg/lOOg at 25°C determined by placing 3 g of water and .03 g of polymer in a test tube at 25°C and shaking the test tube for twenty-four hours. On visual examination, no insoluble polymer particles are observed.

[0018] Fig. 1 shows a typical prior art polymer injection and feed assembly 10. In feed assembly 10, a polymer solution is fed into a manifold block 12, which is used to equally divide polymer flow through four manifold hoses 14 into an injection ring 16. The injection ring 16 has four equally spaced injection ports 18, which are supposed to distribute and inject the polymer into a sludge flow line 20 for mixing with the sludge therein. The polymer and sludge flow together into a mixer 22 where they pass through a restriction created by a trap door that partially blocks the flow (not shown). The small opening between the trapdoor and the mixer body causes high velocity and turbulence, which rapidly mixes the polymer solution with the sludge. A valve stop handle 24 is used to control a valve (not shown) to regulate the flow of sludge through sludge flow line 20. Manipulation of valve stop handle 24 is augmented by counter weight 26. [0019] Conventional wisdom teaches that a polymer solution needs to be injected in an equally distributed fashion around a sludge flow pipe before it enters into a mixer with a waste water stream. I the prior art design of Fig. 1, the polymer is injected at a point of relatively high pressure some distance from the mixing point. However, often there is not equal flow of polymer solution in each of the four hoses and typically, the polymer is not injected uniformly. As soon as the polymer enters the waste water stream, some of it reacts with the solid particles in the waste water stream and begins the fiocculation process (binding the solid particles in suspension into floes or clumps). This occurs while the sludge and polymer mixture is moving from the injection ring toward the mixing point.

[0020] When the mixture of polymer and waste water solids, with some of the polymer already bound to solid particles in the waste water flow, hits the mixing point, the floes and clumps that have already prematurely formed through fiocculation are destroyed, wasting that portion of the injected polymer. The unreacted polymer is then mixed with the sludge flow and fiocculation begins again, but the polymer that was bound to solid particles does not react any further to form clumps again.

[0021] Fig. 2 shows a polymer injection and feed assembly of the present invention. In feed assembly 30, a polymer solution is injected via a polymer feed line 38 directly into a body 32 of a mixer 34 at a single feed point 36. In feed assembly 30, the polymer is injected much closer to a restriction point (minimum opemng 48 as shown in Fig. 3) where turbulent mixing between the polymer solution and a waste water stream occurs. A valve stop handle 40 attached to a counter weight 42 are used to control a valve (adjustable gate 46 in Fig. 3) to regulate the degree of mixing energy of the sludge and polymer passing though the mixer body. An adjustable stop 56 is used to control adjustable gate 46 (Fig. 3) to regulate the flow of sludge through sludge flow line 20 by restricting the movement of valve stop handle 40.

[0022] Fig. 3 shows a cross section of mixer body 32. this preferred embodiment, mixer body 32 has an internal cavity 58, a bottom side 60, and a polymer inlet point 44 on a top portion 54 of mixer body 32. Mixer body 32 further includes adjustable gate 46, which extends from bottom side 60 and is connected to valve stop handle 40. Adjustable gate 46 acts to throttle the flow of the mixture of sludge and polymer solution into a turbulent mixing zone 52 created by a restriction point, which is a minimum opening 48. Adjustable stop 56 sets the minimum opening 48 between a trailing end 62 of adjustable gate 46 and top portion 54 of mixer body 32 by limiting movement of valve stop handle 40 (Fig. 2). Alternatively, a gate stop 50 (as shown in Fig. 3) may be included in top portion 54 to further define opening 48 and turbulent mixing zone 52. Gate stop 50 is positioned such that it could be contacted by trailing end 62 of adjustable gate 46.

[0023] According to the present invention, polymer inlet point 44 is located as close as possible to opening 48. The distance from opening 48 to inlet point 44 may be at least 0.1 cm, in some cases at least 0.25 cm, and in other cases at least 0.5 cm. Typically, inlet point 44 is not more than 10 cm, in some cases not more than 8 cm, and in other cases not more than 5 cm from opening 48. The distance between inlet point 44 and opening 48 may vary between any of the dimensions recited above.

[0024] The force from counter weight 42 acts to hold valve stop handle 40 against adjustable stop 56, maintaining the size of mimmum opening 48. If a foreign object should flow through mixer body 32, the pressure from the sludge feed pump (not shown) will cause the object to push adjustable gate 46 open, against downward force from counter weight 42, allowing the object to flow through mixer body 32. Thus, mixer body 32 is able to clear itself of debris without intervention from an operator. Adjustable stop 56 restricts the movement of valve stop handle 40 and adjustable gate 46 such that trailing end 62 of gate 46 is prevented from contacting the top portion 54 of internal cavity 58, providing a minimal opemng dimension to the restriction point 48.

[0025] The dimension of mimmum opemng or restriction point 48 will depend on the rate of flow through feed assembly 10. For low flow rates, minimum opening 48 will be very small and may be open as fully as possible for large flow rates. Mimmum opemng 48 may be at least 0.1 cm, in some cases 0.25 cm, and in other cases at least 0.5 cm at low flow rates. At higher flow rates, minimum opening 48 may be up to 10 cm, in some cases up to 8 cm, and in other cases up to 5 cm. The size of minimum opening 48 may vary between any of the dimensions recited above.

[0026] In operation, the polymer solution is injected directly into mixer body 32 via polymer inlet port 44 at a point proximate (very close) to and upstream from the restriction point, which is opening 48 created between gate stop 50 and trailing end 62 of adjustable gate 46. The incoming sludge flow sweeps the polymer solution through opening 48 and into turbulent mixing zone 52. The force of the restriction creates violent turbulence in turbulent mixing zone 52, which acts to mix the polymer solution and sludge almost instantly. Downstream from mixer body 32, the sludge pipe is fairly large, which keeps the polymer treated sludge flow velocity low prior to the treated sludge flowing onto the gravity deck of a belt press or gravity belt thickener.

[0027] As described above, the present mixer body could easily be adapted for centrifuge operations and for use with centrifuges.

[0028] With the single polymer injection point and feed assembly of the present invention located close to the mixing point, there is much less time and opportunity for the polymer to prematurely bind to solid particles in the waste water flow. The polymer injected at a single point has less surface area in its injection stream relative to its volume than the four smaller injection streams of the prior art polymer injection and feed assembly, so less polymer has the opportunity to react prematurely with the solid particles in the waste water flow. Most of the polymer reaches the mixing point without being prematurely bound to the waste stream solids so there is little or no waste of the injected polymer. Therefore, the vast majority of the polymer is able to mix and bind with the waste water solids and is not disturbed after the mixing point. Polymer waste due to post injection mixing usually must be replaced with additional polymer. This increases costs. The polymer injection and feed assembly of the present invention provides the possibility of a reduction in polymer consumption, increased sludge cake dryness, and/or better control of the sludge as it passes through a belt filter press. When the present polymer injection and feed assembly is used as the first stage of a waste treatment system using a belt press, improved operation has been observed. When the present polymer injection and feed system is used, large amounts of water are released from the polymer treated waste sludge that is fed to the belt press, resulting in desirable higher solids sludge exiting the belt press operation.

[0029] As such, the polymer injection and feed assembly of the present invention has the ability to significantly reduce the cost of chemical additives for, among other applications, waste treatment. Further, the polymer injection and feed assembly of the present invention provides for improved drainage on the gravity deck of a belt press and better control of the wet sludge between the belts. Trials using the present injection and feed assembly demonstrate a measurable increase in cake solids.

[0030] In a further embodiment of the present invention, the polymer is "made down" in a polymer activation system or mix tank prior to being injected into an aqueous stream using polymer feed line 38 of polymer injection and feed assembly 30. Typically, a mixing chamber or eductor is used to initially mix and dilute the feed polymer (in dry, concentrated solution, gel or emulsion form) into water. A predetermined amount of feed polymer is gradually fed into the mixing chamber or eductor, which is the initial feed polymer/water contact site for initial activation of the feed polymer. Once the feed polymer is fed into water, the polymer is allowed to "activate."

[0031] For a dry polymer, initial activation requires more mixing energy and time because there is minimal water present in the polymer. In addition, the mixing energy required for activation increases with increasing particle size. Activation is easier for solution polymers and gels than for dry polymers; however, the viscous nature of solution polymers and gels makes handling (e.g., pumping) of these polymers difficult. Polymers in emulsion form have a relatively low viscosity when compared to solution polymers, and, therefore, are easier to handle. Emulsified polymers also activate easier than dry polymers because of the small size of polymer particles. Another advantage of emulsified polymers is that they provide higher polymer concentration than solution form.

[0032] Fig. 4 shows an embodiment of the present invention utilizing polymer activation system 84 to make down a dry polymer prior to feeding the polymer to feed assembly 30. In polymer activation system 84, dry polymer 70 is fed to a funnel 86. Water 74 contacts dry polymer 70 in eductor 88, and the resulting mixture flows into mix tank 68. Mix tank 68 may be equipped with a mixer motor 64 attached to a turbine agitator 66. The resulting polymer may be given time to activate, as described above, by closing valve 72. When valve 72 is opened, the polymer solution flows through polymer feed line to feed assembly 30 as described above.

[0033] Fig. 5 shows a further embodiment of the present invention utilizing polymer activation system 80 to make down and activate a liquid polymer prior to feeding the polymer to feed assembly 30. In polymer activation system 80, liquid polymer is fed to mixing chamber 76 via polymer inlet 78 and water is fed via water inlet 82. The liquid polymer is diluted into the water in mixing chamber 76 and fed to feed assembly 30 via polymer feed line 38. Any suitable mixing chamber may be used for mixing chamber 76. Suitable mixing chambers include, but are not limited to, the dynaBLEND system available from Fluid Dynamics, Inc., Boulder, Colorado.

[0034] As one skilled in the art can appreciate, various combinations of eductors and mixing chambers may be used in the present invention. A nonlimiting example, the liquid polymer for polymer activation system 80 may be supplied from polymer activation system 84 in Fig. 4. [0035] The made down and activated polymer solution is fed to the present polymer injection and feed assembly via polymer feed line 38. The activated polymer solution is then injected into and mixed with an aqueous stream of solid particulates to induce fiocculation.

[0036] The present polymer injection and feed assembly may be used to inject and mix polymers into various aqueous streams containing particulate matter. Applications where the present polymer injection and feed assembly are useful include, but are not limited to, waste water purification and fiocculation, automotive paint spray booths, in the chemical industry to separate inorganics and solids from effluent, in the coal industry to promote solids settling and to float coal fines, in the petrochemical industry to enhance oil recovery, in the phosphate industry to improve recovery, in the pulp and paper industry as dewatering aids and retention aids, or in the steel industry to settle waste.

[0037] The flow through the polymer injection and feed assembly 30, indicated by the directional arrows in Fig. 2 will vary considerably depending on the particular application or use as well as individual operating conditions. The flow through the polymer injection and feed assembly may be, on occasion, less than 1 1/min, but will typically be at least 1 1/min. Depending on the particular operation, the flow rate may be at least 2 1/min, in some cases at least 4 1/min, in other cases at least 10 1/min, under some conditions at least 20 1/min, under other conditions at least 50 1/min, in some situations at least 100 1/min, and in other situations at least 250 1/min. When required, large flow rates may be accommodated by the polymer injection and feed assembly. The flow rate maybe up to 5,000 1/min, in some cases up to 4,500 1/min, in other cases up to 4,000 1/min, under some conditions up to 3,500 1/min, under other conditions up to 3,000 1/min, in some situations up to 2,500 1/min, and in other situations up to 2,000 1/min. The flow rate through the polymer injection and feed assembly may vary between any of the flow rates recited above.

[0038] The flow of the made down polymer through polymer feed line 38 into mixer body 32 (Fig. 3) will vary depending on the desired polymer dose and the polymer concentration in the made down liquid polymer. The liquid polymer flow rate may be at least 1 ml/min, in some cases at least 2 ml/min, under some conditions at least 5 ml/min, under other conditions at least 10 ml/min, in some situations at least 25 ml/min, and in other situations at least 100 ml/min. The liquid polymer flow rate may be up to 25,000 ml/min, in some cases up to 20,000 ml/min, in other cases up to 15,000 ml/min, under some conditions up to 10,000 ml/min, under other conditions up to 5,000 ml/min, in some situations up to 2,500 ml/min, and in other situations up to 1,000 ml/min. The liquid polymer flow rate may vary between any of the flow rates recited above.

[0039] The concentration of made down polymer in the liquid polymer will vary depending on the molecular weight of the polymer, the liquid polymer viscosity and the desired rate of polymer addition. The liquid polymer may contain polymer at a level of at least 0.1 wt. % and in some cases at least 0.5 wt. %, in other cases at least 1 wt. %, and typically at least 1.5 wt. %. The liquid polymer may contain polymer at a level of up to 10 wt. %, in some cases up to 8 wt. %, in other cases up to 6 wt. %, in some situations up to 5 wt. %, in other situations up to 4 wt. %, under some conditions up to 3 wt. %, and typically up to 2 wt. %. The amount of polymer in the liquid polymer may vary between any of the concentrations recited above.

[0040] The amount of polymer applied (polymer dosage) in a given application is typically expressed as pounds of dry polymer per ton of dry solids (particulate matter) being treated. The actual amount of polymer applied will vary depending on the particular application. The polymer dosage may be at least 1 lb/ton, in some cases at least 2 lb/ton, in other cases at least 3 lb/ton, and typically at least 5 lb/ton. Further the polymer dosage may be up to 50 lb/ton, in some cases up to 45 lb/ton, in other cases up to 40 lb/ton, and typically up to 35 lb/ton. The polymer dosage may vary between any of the application levels recited above.

[0041] Any water-soluble or water-dispersible polymer may be used with the present polymer injection and feed assembly. An example of polymers that are typically used with the present polymer injection and feed assembly are acrylamide containing polymers and copolymers. Examples of copolymers of acrylamide include, but are not limited to anionic copolymers with monomers such as acrylic acid, methacrylic acid and acrylamidomethyl propane sulfonic acid and their corresponding salts and cationic copolymers with monomers such as diallyl dimethyl ammonium chloride, methacrylamidopropyl trimethyl ammonium chloride and methacryloyloxyethyl trimethyl ammonium chloride. The polymers and copolymers may be supplied in dry, solution, gel or water-in-oil emulsion form.

[0042] The present invention is also directed to a method of applying a polymer to an aqueous stream. In the method, the present polymer injection and feed assembly 30, as described above, is provided. An aqueous stream flows through sludge line 20. A liquid polymer is fed to polymer injection and feed assembly 30 just prior to the restriction point, which is opening 48, and the liquid polymer and aqueous stream are turbulently mixed in turbulent mixing zone 52. The mixture subsequently exits polymer injection and feed assembly 30 to be further processed.

[0043] As mentioned above, the further processing may include fiocculation of suspended solids followed by solid liquid separation, injection into an earthen well to effect enhanced oil recovery, feeding to a paper machine for the manufacture of paper and the like, and other applications known in the art.

[0043] The present invention is further directed to a method of applying a polymer to an aqueous stream. In the method, the polymer injection and feed assembly described above is provided, and an aqueous stream is allowed to flow through the internal cavity of the mixer body. A polymer is applied to the aqueous stream by way of the polymer injection and feed assembly, at a single feed point in the mixer body, just upstream from the restriction point, such that turbulent mixing of the polymer and the aqueous stream occurs at and downstream of the restriction point. The mixture of polymer and the aqueous stream then exits the polymer injection and feed assembly.

[0044] The polymer is typically a water-soluble polymer and may be in any physical form including, but not limited to, dry powders, water-in-oil emulsions, oil-in- ater emulsions, suspensions, and solutions. Prior to applying the polymer, the polymer may be made down in a polymer activation system or a mix tank. A mixing chamber and/or an eductor may be used to aid in mixing and diluting the polymer into water. Time for polymer activation may be provided for, as discussed above, prior to applying the polymer. The polymer make down apparatus is typically in fluid communication with the polymer feed line to the polymer injection and feed assembly.

[0045] The aqueous stream entering the polymer injection and feed assembly may be any suitable aqueous stream including, but not limited to, waste water streams, detakification of automotive paint spray booth waste streams, waste streams containing inorganic materials, waste streams containing solids requiring solid-liquid separation, coal waste streams, aqueous streams for enhanced oil recovery; phosphate waste streams, aqueous streams used in papermaking, and steel industry waste streams.

[0046] Accordingly, the present polymer injection and feed system may be used for various applications, including, but not limited to, waste water purification, waste water fiocculation, detakification of automotive paint spray booth waste streams, and removal of paint waste, separation of inorganic wastes, solid-liquid separation, coal fine flotation, enhanced oil recovery, recovery improvement in phosphate mining, and paper manufacture.

[0047] The present invention has been described with reference to specific details of particular embodiments thereof. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that such modifications and alterations be within the scope of the invention, as set forth in the accompanying claims.

Claims

We Claim:

1. A polymer injection and feed system comprising: a mixer body having an internal cavity to allow an aqueous stream to flow therethrough; an adjustable gate positioned inside the mixer body; a restriction point defined by a trailing end of the gate and a top portion of the internal cavity of the mixer body; and a single polymer feed line communicating with the internal cavity proximate the restriction point, wherein the restriction point induces turbulent mixing of a polymer with the aqueous stream.

2. The polymer injection and feed system of claim 1, further comprising a polymer make down apparatus in fluid communication with the polymer feed line.

3. The polymer injection and feed system of claim 2, wherein the polymer make down apparatus comprises one or both of a mixing chamber and an eductor.

4. The polymer injection and feed system of claim 1, further comprising a gate stop protruding from the top portion of the internal cavity such that it may be contacted by the trailing end of the gate.

5. The polymer injection and feed assembly of claim 1, further comprising a valve stop handle connected to the gate and located external to the internal cavity, the valve stop handle attached to a counter weight.

6. The polymer injection and feed assembly of claim 5, further comprising an adjustable stop located external to the internal cavity and in proximity to the valve stop handle such that the adjustable stop may be positioned to limit the movement of the valve stop handle, thereby preventing the trailing end of the gate from contacting the top portion of the internal cavity to provide a minimum opening for the restriction point.

7. The polymer injection feed assembly of claim 6, wherein the minimum opening is from about 0.1 cm to about 10 cm.

8. The polymer injection and feed assembly of claim 1, wherein the distance from the restriction point to the polymer feed line is from about 0.1 cm to about 10 cm.

9. A polymer injection and feed system comprising:

(a) a polymer make down apparatus comprising a mixing chamber and/or an eductor;

(b) a mixer comprising:

(i) a mixer body with an internal cavity to allow an aqueous stream to flow therethrough;

(ii) a gate having a pivot end pivotally attached to a lower portion of the internal cavity and a trailing end;

(iii) a gate stop protruding from a top portion of the internal cavity such that it may be contacted by the trailing end of the gate;

(iv) a restriction point defined by the trailing end of the gate and the gate stop;

(v) a valve stop handle connected to the gate and located external to the internal cavity, the valve stop handle attached to a counter weight; and

(vi) an adjustable stop located external to the internal cavity and in proximity to the valve stop handle such that the adjustable stop may be positioned to limit the movement of the valve stop handle, thereby preventing the trailing end of the gate from contacting the gate stop, providing a mimmum opening for the restriction point; and

(c) a single polymer feed line communicating the polymer make down apparatus with the internal cavity, proximate the restriction point, wherein the restriction point induces turbulent mixing of a polymer with the aqueous stream.

10. A method of applying a polymer to an aqueous stream comprising:

(a) passing an aqueous stream through an internal cavity of a mixer body; (b) providing a restriction point in the internal cavity of the mixer body; and

(c) introducing a polymer to the aqueous stream through a single polymer feed line communicating with the internal cavity proximate and upstream of the restriction point,

(d) passing the polymer and aqueous stream through said restriction point; and

(e) mixing the polymer with the aqueous stream in a turbulent manner.

11. The method of claim 10, wherein the physical form of the polymer is selected from the group consisting of dry powders, water-in-oil emulsions, oil-in-water emulsions, suspensions, and solutions.

12. The method of claim 10, further comprising the step of making down the polymer in one of a polymer activation system or a mix tank prior to introducing the polymer in step (c).

13. The method of claim 12, wherein the polymer activation system comprises one of a mixing chamber and an eductor, which mixes and dilutes the polymer into water.

14. The method of claim 10, further comprising the step of activating the polymer prior to introducing the polymer in step (c).

15. The method of claim 10, wherein the aqueous stream is selected from the group consisting of waste water sfreams, detakification of automotive paint spray booth waste streams, waste streams containing inorganic materials, waste streams containing solids requiring solid-liquid separation, coal waste streams, aqueous streams for enhanced oil recovery, phosphate waste streams, aqueous streams used in papermaking, and steel industry waste streams.

16. The method of claim 10, wherein the polymer is a water soluble-polymer.

17. The method of claim 16, wherein the water-soluble polymer is one or more water-soluble homopolymer or copolymer of one or more monomers selected from the group consisting of acrylamide, acrylic acid, methacrylic acid, acrylamidomethyl propane sulfonic acid, diallyl dimethyl ammonium chloride, methacrylamidopropyl trimethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride, and their corresponding salts.

18. The method of claim 10, wherein the aqueous stream passes through the internal cavity of the mixer body at a flow rate of from 1 1/min to 5,000 1/min.

19. The method of claim 10, wherein the polymer is a liquid polymer that is introduced to the internal cavity of the mixer body at a flow rate of from 1 ml/min to 25,000 ml min.

20. The method of claim 19, wherein the liquid polymer contains a polymer at a concentration of from 0.1 wt. % to about 10 wt. %.

21. The method of claim 10, wherein the aqueous stream contains solids and the polymer is introduced at a polymer dosage of from 1 lb/ton to 50 lb/ton.