GB2192806A

GB2192806A - Mixing and activating polymers

Info

Publication number: GB2192806A
Application number: GB08713113A
Authority: GB
Inventors: Dennis Pardikes
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-06-05
Filing date: 1987-06-04
Publication date: 1988-01-27
Anticipated expiration: 2007-06-04
Also published as: IT8720802A0; FR2606700B1; DE3718818A1; GB8713113D0; JPS6339927A; DE3718818C2; FR2606700A1; GB2192806B; JP2628163B2; IT1204686B

Description

GB2192806A 1

SPECIFICATION

System for mixing and activating polymers This invention relates to means for and methods of mixing and activating polymers, at a high 5 speed, and in either batch or continuous loads, while being able to control, select and maintain polymer concentration and activation.

Liquid or emulsion polymers are ionic-charged organic molecules which are water soluble.

Unactivated or neat polymers are encased by an oil carrier. In this phase, the molecule is coiled upon itself in the lipid sack. Due to its charge, it tries to uncoil, but the oil carrier overcomes the 10 charge and keeps it coiled.

Liquid polymers are used by various industries to simplify their industrial processes and make them more economical. For example, liquid polymers may be used for water purification and flocculation; may be used in automotive paint spray booths; may be used in the chemical industry to separate inorganics and solids from plant effluent; may be used in the coal industry 15 to promote solids settling and to float coal fines; may be used in the petro-chemical industry to enhance oil recovery may be used in the phosphate industry to improve recovery; may be used in the pulp and paper industry as dewatering aids and retention aids; may be are used in the steel industry to settle wastes. Those familiar with this art will readily perceive uses in many other industries. 20 Usually polymers are manufactured and shipped in a deactivated form to a location where they will be used. At that location, it is necessary to activate the polymers before they can be used.

Usually, that means that a polymer must be mixed with water, or with a chemical, to provide an electrolyte which can change the polymer from an inactive state which can not easily be mixed with any other substances into an active state which can be so mixed. The process for so 25 converting the polymer into an active state is one of imparting a sufficient amount of energy to the polymer. Reference may be made to U.S. Patents 4,057,223 and 4,217, 145 for two examples of prior art polymer activating systems.

The polymer encased in oil is inactive and, therefore, its lipid surrounding sack must be broken to allow the ionic molecule to uncoil. The way in which emulsion polymers are activated are to 30 dilute them with water and to add enough mixing energy to emulsify the oil carrier and enable the ionic charged molecule to uncoil. More particularly, the energy imparted to the inactive polymer includes a mechanical agitation which breaks down the liped coating, and thus enables water or another electrolyte to reach the long coiled molecule. Once that molecule is in water, like charges on the molecule repell each other and the molecule straightens and changes from 35 the coil into a long and more or less straight configuration. Until this straightening occurs, the molecule is useless for most purposes.

The exact amount of energy required for an emulsion polymer activation is not know. How ever, there is an increase in the viscosity of the polymer, which is proportional to its activation.

This increase in visosity is due to the uncoiled molecules interwining with each other. The 40 uncoiling of the molecules provide active sites for the attachiment of foreign material on a medium. Then, the increased weight on these molecules settles them, carrying with them the unwanted material.

In the utilization of emulsion polymers, care must be taken to properly prepare the polymer.

Different polymers require different amounts of energy for activation, tougher polymers require 45 more force, while others need less force. Further, care must be taken not to overshear the molecules. Overshearing tends to break the uncoiled molecules, thus lowering their viscosity and making them less effective. Undershearing also is deleterious in that the polymer is then ineffici ent and uneconomical.

The known activating systems have required relatively long periods of time (such as an hour 50 or so) in order to, for example, complete the activation of the other polymer. This long period of time increases the requirements for holding tanks during activation. Therefore, the relatively long period of activation time is relatively expensive. Also, the requirement for such a long term for activation greatly increases the capital requirements for the purchase of machinery when a system is operating continuously, as opposed to a batch system. Thus, a faster polymer 55 activating system is highly desired.

Primarily, the prior art used the batch method to activate liquid polymers. Polymer and water are delivered to a common mixing tank. Once in the tank, the solution is beat or mixed for a specific length of time in order to impart energy thereto. After mixing, the resulting solution must age to allow enough time for the molecules to unwind. 60 Accordingly, an object of the invention is to provide new and improved means for and methods of activating polymers. In particular, an object is to provide a quicker, multi-stage procedure which lends itself to either batch or continuous processing. Here, an object is to provide a system for activating polymers in one or more seconds depending upon the particular polymer being activated. 65 2 GB2192806A 2 A further object of the invention is to substantially eliminate the need for holding tanks while a partially activated polymer ages.

Yet another object of the invention is to provide an efficient system and method for activating liquid polymers. Here an object is to provide an automatic, continuous system which is able to vary the output rate of activated polymer, while automatically maintaining the amount of energy 5 imparted thereto and while maintaining a desired concentration of the polymer.

Still another object of the invention is to substantially reduce aging time, and in many cases to completely eliminate aging time, which in turn reduces captial cost.

In keeping with an aspect of the invention, the activation of a polymer occurs in four stages, which are: pre-mixing, blending, recycling, and a final sudden pressure reduction. The pre-mixing 10 occurs in a manifold containing a static mixer. The blending occurs within a centrifugal pump where water or another electrolytic substance (or mixtures thereof) are blended with the poly mer. The outflowing stream from the centrifugal pump divides with part of the outflow feeding back through the static mixer and centrifugal pump. The other divided part of the outflow is delivered to a mixing pressure regulator where the pressure imparted by the centrifugal pump is 15 suddenly reduced to, or near, atmospheric pressure. This suddenly relaxes the long coiled polymer molecule to hasten its straightening. In one exemplary system, the entire activation requires only about one second.

The invention enables an adjustment which controls the amount of energy introduced into the polymer for activation. Once the relationship between the amount of introduced energy and the 20 output rate is established, the inventive system automatically compensates for variations therein.

The system also provides controls for varying the concentration of the polymer.

Preferred embodiments of the invention are shown in the attached drawings, wherein:

Figure 1 schematically shows the principles of an inventive system having two inputs, which are for water and for the polymer that is to be activated; 25 Figure 2 is a perspective view of a pre-mixing manifold; Figures 3A and B are two plan (rotated by 90' from each other) views a static mixer which is used inside the manifold of Fig. 2; Figure 4 is an end view of the static mixer, taken along line 4-4 in Fig. 3A; and Figure 5 is a schematic showing of a more sophisticated version of the system of Fig. 1 with 30 provisions for introducing one or more chemicals which may be used in the electrolyte for activating the polymer; Figure 6 is a front plan view of a system incorporating the invention; and Figure 7 is a plan view of the inventive system taken along lines 7-7 of Fig. 6.

In Fig. 1, the system components are an input throttling valve 20 for controlling the ratio of 35 water to polymer, a centrifugal pump 22 for introducing the water, a closed mixing loop 24, a pre-mixing manifold 26, a centrifugal pump 28, for introducing the polymer. The water and polymer first meet in the pre-mixing manifold 26, the water flow being indicated in Fig. 1 by solid lines and the polymer flow being indicated by dashed lines. Valve 20 may be set to provide a ratio of water to about 1 % polymer in one example, with a useful range of ratios 40 being in the order of.25 to 15% polymer. Associated with valve 20 may be a meter (not shown) which is calibrated in gallons per minute. By an adjustment of the valve 20, one can also select the desired output of the system.

The mixing pressure regulator 30 is critical in three areas. It is used to maintain a constant net positive discharge head on the booster module or centrifugal pump 22, which is an important 45 consideration in the hydraulics of the system. It controls the amount of recycling which occurs in the recycle stage. It provides a variable pressure drop zone in the final stage and enables the operator to select a proper amount of mixing energy, based on the type and concentration of polymer being processed. The higher solids polymers and higher solution concentrations require more mixing energy than usual. 50 In greater detail, the mixing manifold 26 (Fig. 2) is, for example, a solid block of metal having a central bore 32 extending through substantially its entire length. The bore 32 stops short of a counterbored and threaded input opening 34, to form a bulkhead 36. An orifice 38 of fixed diameter is formed in the center of the bulkhead 36 to establish communication between the water inlet hole 34 and the central bore 32, with a flow rate that is controlled by the orifice 55 diameter.

3 GB2192806A 3 TABLE 3:

AN EXEMPLARY FLOW RATE AND RECYLCE VOLUME IN ONE EXEMPLARY SYSTEM 5 TYPE OF DIAMETER OF SOLUTION OUTPUT RECYCLE PUMP ORIFICE 38 (GALLONS PER MINUTE) VOLUME GPM 054 AnCAT. 3/3211 to 3/16".25 to 10 gpm 1.85 at 40 psi to - 8.12 at 60 psi 10 L-10 AnCAT 1/811 to 1/411 3 to 10 gpM 2.56 at 30 psi to 14.5 at 60 psi L-20 AnCAT 1/8" to 1/41, 3 to 20 gpm 2.56 at 30 psi to 15 14.5 at 60 psi L-30 AnCAT 1/811 to 3/811 3 to 30 gpm 2.56 at 30 psi to 32.5 at 60 psi 20 L- 0 AnCAt 3/1611 to 1/311 5 to 60 gpm 5.75 at 30 psi to 57.8 at 60 psi L-80 AnCAT 3/1611 to 5/811 5 to 80 gpm 5.75 at 30 psito 90.4 at 60 psi 25 L-100 AnCAT 3/1611 to 3/4" 5 to 100 gpm 5.75at 30,psi to 130.0at 60 psi 30 A first transverse, threaded hole 40 leads to another bulk head 42 between the entrance to the counter bored and threaded hole 40 and the central bore 32. An orifice 44 is formed in the bulkhead 42 to establish communication and to control the flow rate between the hole 40 and the central bore 32.

The output port 46 is in direct communication with the central bore 32 to give an unimpeded 35 outflow of a mixture of polymer and water.

A static mixer 50 (Figs. 3,4) comprises two sets of semi-elliptical baffles which are set at an angle to each other so that the over all end view configuration is a circle (Fig. 4). The baffles 52 (Fig. 3A) on one side of the static mixer are a series of spaced parallel plates. The baffles 54 on the other side of the static mixer are joined on alternate ends to give an over all zig-zag 40 appearance. The outside diameter (Fig. 4) of the static mixer corresponds to the inside diameter of the central bore 32. Therefore, the static mixer 50 slides through an end opening 56 and into the bore 32. Thereafter a plug 58 seals off the end of the bore. In one embodiment, the static mixer 50 is a standard commercial product from TAH Industries of Inlaystown, N.J.

Water is introduced into the mixing loop 24 (Fig. 1) through the centrifugal pump 22 and is 45 controlled and metered by the throttling flow valve and meter at 20. The beginning stages of activation or pre-blend stage occurs inside the centrifugal pump assembly 22.

The centrifugal pump 22 is a modified commercial item which is derated on the high end of its output flow by a factor in the order of 2 to 7, for example, for most applications. On the low end of its output flow, the derating factor may be much higher. That is the diameter of the 50 impeller is trimmed to give a degraded performance wherein there is a larger amount of stiring and mixing per volume flow as compared to what might normally be expected from standard commercial centrifugal pump. Dearating is also controlled by an adjustment of the water inlet flow. In greater detail, by way of example, a centrifugal pump usually has a series of flow charts which are supplied by the manufacturer. One flow chart, which may be the one normally used, 55 may describe how the pump could provide a flow of 20-gallons per minute to the top of a 40 foot head, for example. Another flow chart may describe how the same pump could be operated at a different speed to provide five times that capacity, or at 100-gallons per minute to the same 40-foot head, in this particular example.

According to the invention, the pump is operated in the manner described by the manufacturer 60 to deliver 100-gallons per minute, but the diameter of the impeller is reduced until the delivery returns to 20- gallons per minute, while the pump continues to be operated in the manner which the manufacturer suggests for 100-gallons per minute. Thus, in this particular example, the centrifugal pump has been derated by a factor of 5 (i.e. derated from 1 00-to-20-ga I Ions per minute) After derating, the increased impeller speed, which is normally required to deliver 100- 65 4 GB2192806A 4 gallons per minute imparts a higher level of energy to the mixed fluid, without increasing the volume of fluid output.

The following chart illustrates a number of different pumps which may be used for polymer injection at 28.

5 TYPE PUMP FLOW RATE 054 AnCat 0-864 gpd L-10 AnCAT 0-2160 gpd L-20 AnCAT 0-4320 gpd L-30 AnCAT 0-6480 gpd 10 L-60 AnCAT 0-12,960 gpd L-80 AnCAT 0-17,280 gpd L-100 AnCAT 0-21,600 gpd In pump type L-60, the impeller diameter was 5-inches; in pump type L-80, it was 6-inches, 15 and pump type L-100, it was 6.25-inches.

The unactivated emulsion polymer is introduced through the premix manifold 26 and into the mixing loop 24 by a varaible speed, positive displacement pump 28 which delivers the polymer at a rate which achieves, a range of desired concentrations. A calibration column (not shown) is provided to correlate the variable speed pump 28 to its capability to deliver the unactivated 20 polymer at a rate which accurately obtains the desired concentration. The pump 28 is not modified and merely delivers the polymer to the mixing manifold 26.

The mixed water and polymer solution is recycled, via loop 24, back throught the premix manifold 26 and the booster module (centrifugal pump 22) which continues to boost the activation level of the polymer. 25 The final stage of polymer activation is controlled by the mixing pressure regulator 30. The polymer solution passing through the regulator 30 experiences a sudden pressure drop which fully activates the solution. This pressure drop is adjustable and represents an important factor in the development of fully activated polymer molecules. The pressure regulator 30 is a standard commercial item. 30 More specifically, the mixing pressure regulator 30 is provided in the mixing loop to enable a discharge of the activated polymer at a desired level of activation while, maintaining a net positive suction head in the centrifugal pump to prevent cavitation. Once the desired output rate and level of activation is selected, the mixing pressure regulator 30 automatically compensates for any surging or ebbing flow which are attendant upon changes in the output flow rate. Thus 35 pressure regulator 30 maintains the desired level of activation in the centrifugal pump 22.

It should now be apparent that the mixing pressure regulator is critical in three areas. It is used to maintain a constant net positive discharge head on the booster module, which is an important consideration in the hydraulics of the system. It controls the amount of recycling which occurs in the recycle stage. It provides a variable pressure drop zone in the final stage 40 and enables the operator to select a proper amount of mixing energy, based on the type and concentration of polymer being processed. The higher solids polymers and higher solution concentrations require more mixing energy than usual.

Regulator 30 is set to cause a sudden and abrupt relaxation of pressure, from the pressure in line 60 to or near atmospheric pressure. This sudden and abrupt relaxation causes an effect 45 which is somewhat similar to the aging which occurs in a holding tank in prior art systems. A limiting factor is that the pressure regulator 30 can not be adjusted to operate at any level which causes cavitation in the pump 22.

The solution output of the system with the various pump described above may be, as follows:

50 054 AnCat.13 to 10 gpm L-10 AnCAT 3 to 10 gpm L-20 AnCAT 4 to 20 gpm L-30 AnCAT 4 to 30 gpm L-60 AnCAT 5 to 60 gpm 55 L-80 AnCAT 5 to 80 gpm L-100 AnCAT 5 to 100 gpm The system also has a flow sensor (not shown) which senses the flow rate of the solution in the system. If a low water flow rate condition is sensed, (i.e. a flow below three gallons per 60 minute for the L-10 pump), the system is automatically shut down and alarms are sounded.

Further, a compound gauge 61 in the mixing loop provides means for a visual inspection of the operating conditions of the pump.

In operation, the invention provides an automatic system for activating emulsion polymers at desired output rates and desired levels of activation. The system provides homogenous, acti- 65 GB2192806A 5 vated, solutions at desired concentrations. The system is fast, inexpensive, reliable, and provides variable capabilities which are not offered by other known systems.

More particularly, the system takes in polymer at inlet 62 and water at inlet 64. The throttling valve 20 is set to regulate the amount of inflowing water and, therefore, the ratio of water to polymer. The diameters of the pipes, apertures, impedance of the static mixing device 50, etc. 5 cause an outflow of pump 22 to divide at point 66. The ratio selected for the division depends upon the nature of the product. In an exemplary system, about 60% of the outflow of pump 22 passes through pipe 60 and the pressure regulator 30 to the output of the system. The remaining approximately 40% of the outflow from pump 22 recirculates to the pre-mixing manifold 26, from which, it is fedback at 68 to the centrifugal pump 22. Thus, the feed back 10 loop 24, 66, 26, 68, 22 always contains the combination of a previously mixed solution of water and polymer and a new mixture of fresh stock and a feedback mixture.

It should now be clear that the inventive system has four stages: pre-mix, blend, recycling, and final stage. The pre-mix occurs in the mixing manifold 26 when the raw polymer first meets the water. The turbulence caused by baffles 52, 54 (Fig. 3) of the static mixer 50 tends to 15 thoroughly mix the polymer and water, but the lipid sack surrounding the coiled polymer mole cule may remain unbroken.

The blend stage starts in the centrifugal pump 22 where the lipid sack begins to be or is broken, at a first level of activation, The recylcing stage occurs in the feed back loop 24 where about 40% of the outflow of 20 pump 22 continues to receive an imparted amount of energy to fully break the lipid sack. A level of equilibrium and stability is soon reached wherein virtually all of the lipid sacks are broken by the time that the outflow reaches the outlet pipe 60, where the polymer is to become fully activated.

The final stage occurs when there is a sudden pressure drop in regulator 30 which relaxes the 25 polymer molecule. Then, the similar charges along the long polymer molecule repell each other and cause it to straighten in response to the sudden reduction of pressure in regulator 30.

The principles and the apparatus described thus far may be expanded and modified to provide systems which are custom designed for activating various polymers in various electrolytes.

These changes are illustrated in Fig. 5 where the format of the piping system has been modified 30 to mix a polymer with, not only water, but also additional chemicals. In this particular example, the polymer is mixed with dimethylamine ("DMA") and formaldehyde. In its pure form, DMA is a highly flammable material which should not be brought into a factory. Therefore, DMA is introduced via a pump 80, the output of which is connected to the water input pipe 64 while it is outside the factory and before it reaches the throttle valve 20. After the DMA is mixed with 35 water, it may be safely pumped into the factory.

The formaldehyde may safely be handled within a factory area; therefore, it is introduced via pump 81 which may be at any convenient location. The formaldehyde is injected into the mixture of water and DMA before it reaches the pump 22 and the polymer.

The remainder of the system in Fig. 5 is the same as the system of Fig 1. Therefore, it will 40 not be described again. The out flow from pressure regulator 30 is a composition comprising a polymer mixed into a carrier of water, DMA, and formaldehyde.

Figs. 6 and 7 shows a practical embodiment of an inventive system which incorporates the principles set forth in figs. 1-5. The system 110 is adapted to receive water and neat emulsion polymer in a mixing loop 112 in order to mix and activate the emulsion polymer at desired 45 levels of activation energy. The system 110 further provides a continuous output of activated emulsion polymer at desired rates through discharge outlet 114.

The mixing loop 112 includes a static mixing manifold or chamber 116 and a booster module or centrifugal pump 118 in fluid communication with each other through conduits 120 and 122.

The unactivated or neat polymer is introduced through conduit 124 and into the mixing loop 50 112, for activation, in the premix manifold or chamber 116. The water is supplied to a water inlet 126 which is in fluid communication with the mixing loop 112 through conduit 128.

Neat polymer is supplied from a source to the conduit 124 through shutoff valve 130 and pump 132. The system 110 is capable of automatically selecting the desired concentration of the activated polymer once the desired flow rate of water is selected. This accomplished by 55 motor 134 coupled through gearbox 136 to the pump 132. The motor 134 receives its power from control panel 140 through electrical cable 138. The gearbox 136 enables an adjustment of the polymer feed rate through the pump 132 to the mixing loop 112.

The gearbox 136 is calibrated for each polymer which is utilized, because different solution concentrations produce different flow rates, for the same pump speed. The calibration is accom- 60 plished by closing shut-off valve 130 and by filling calibration column 142 with the polymer which is to be used. The calibration column 142 supplies its polymer to the pump 132. By correlating the rate of decrease of polymer in the column 142 to an adjustment member 144 on the gearbox 136, the polymer is delivered at a selected rate to the mixing loop 112. The shut- off valve 130 can then be opened to supply polymer at the desired rate. 65 6 G13 2,192 806A 6 Gauges 146 and 148 are coupled to the inlet and discharge sides, respectively, of the pump 132. These gauges provide a visual inspection of proper pump operation. Gauge 146 is a vacuum pressure gauge and indicates suction pressure of the pump. Gauge 148 monitors the discharge pressure of the pump. High level valves on gauge 148 warns of blockage in the pump 132 or in the premix manifold or chamber 116 and leads to a deactivation of the system in 5 order to ascertain and correct the cause of a malfunction.

The water is supplied to the mixing loop 112 via the conduit 128, a metering valve 150, and a flow rate indicator 152. The flow rate indicator 152 is calibrated in gallons per minute. By adjusting valve 150, one can select the desired rate of output of activated polymer solution. The flow rate indicator 152 includes a low flow sensor. When a low flow condition is sensed in the 10 system, an impulse is sent through electrical cable 154 to the control panel 140, which deactivates the system and sounds an alarm to alert an operator.

A mixing pressure regulator 156 communicates between the discharge outlet 114 and the mixing loop 112. The pressure regulator 156 contains an adjustment 158 for varying pressure within the mixing loop 112 to achieve a desired level of activation of the emulsion polymer. 15 The booster module or centrifugal pump 118 supplies a motive force for mixing the polymer and water and for moving it through the mixing loop 112. The centrifugal pump 118 receives its power from the control panel 140 via cable 162. A gauge 164 is provided to visually inspect the operating condition of the pump 118. The gauge 164 is a compound gauge which is coupled to the premix manifold or chamber 116, to indicate the suction pressure of the pump 20 118. The conduit 120 includes a visual flow indication viewing window, for the mixing loop.

Gauge 166 is coupled to the conduit 122 and gives values for the mixing pressure within the mixing loop.

The discharge outlet discharges the activated polymer either to a tank (not shown) or directly to a processing system (also not shown). Cable 168 communicates between the control panel 25 and the tank. When a predetermined level of activated polymer is sensed in the tank, the control panel deactivates the system.

Once the desired levels of output and energy levels are selected, the system automatically operates the pressure regulator 156 to changes the flow rate of the water to maintain the level of pressure in the mixing loop 112 which provides the desired level of activation energy. 30 Pressure within the mixing loop 112 dictates how much polymer recirculates, which in turn is directly proportional to the introduction of activation energy. Therefore, with an increase in mixing pressure, via the mixing pressure regulator, the pressure in the loop increases which means more polymer recirculation.

The mixing loop 112 not only provides a balance to achieve a desired output rate and a 35 desired level of activation energy, but also provides a regulation to prevent a cavitation of pump 118. In order to get a flow rate out of the pump 118, it is necessary to supply it with its net positive suction head (NPSH) requirement. Cavitation or boiling of the liquid occurs if there is a failure to supply the pump 118 with its required NPSH. Therefore the regulator 156 and valve 150 balance the loop 112 and provide variations in the output rate and in the level of activation 40 energy, within ranges to regulate NPSH requirement of pump 18.

The system is an automatic, efficient, low cost apparatus for mixing and activating emulsion polymers. More particularly, the system 110 provides an ultimate control over an activated polymer concentration which is in the range of about.10 to 15 percent. Also, the system 110 automatically provides a variable rate output, while maintaining critical mixing pressures for the 45 introduction of controlled mixing energy to the emulsion polymer.

Those who are skilled in the art will readily perceive how to modify the invention. Therefore, the appended claims are to be construed to cover all equivalent structures which fall within the true scope and spirit of the invention.

50

Claims

CLAIMS (1) A system for activating polymers, said system comprising a

centrifugal pump having a high speed impeller relative to a limited volume of outflow produced by said impeller, mean for coupling a source of an electrolyte to an input to said pump, a pre- mixing manifold having a static mixer contained therein, a pressure regulator, said pressure regulator and an output of said 55 pump being connected to a first input of said manifold, means for coupling a source of a polymer to a second input of said manifold, and a connection between an out put of said mixing manifold and an imput to said pump, whereby a feed back loop is formed for recirculating a portion of the out put of said pump.
2. The system of claim 1 wherein said pump is a centrifugal pump with an outflow of said 60 pump derated by a factor of approximately five.
3. The system of claim 1 wherein said pump is derated by a factor in the range of 2-7.
4. The system of claim 1 wherein said pressure regulator abruptly and quickly reduces the pressure in the non-Fed-back portion of said output of said pump, said reduced pressure being low enough to cause a relaxation of molecules in said polymer while also being high enough to 65 7 GB2192806A 7 prevent a cavitation in said pump.
5. The system of claim 1 wherein the output of said pump divides in a ratio wherein approximately 30-60% of the output goes to said first input to said manifold and approximately 70-40% to said output goes to said pressure regulator.
6. The system of claim 1 and means for introducing water through said input of said pump 5 to said first input of said manifold.
7. The system of claim 6 and a format of pipes associated with an inlet to said pump for introducing a plurality of chemicals into an input of said pump for pre- mixing to form an electrolye for said polymer.
8. The system of claim 7 wherein a first of said format of pipes is connected to a source of 10 dimethylamine, a second of said format of pipes is connected to a source of formaldehyde, and a third of said format of pipes is connected a source of water.
9. The system of claim 8 wherein dimethylamine is introduced to said first of said format pipes at a remote location where there is protection from the hazzard of a fire.
10. A variable rate, continuous output system for activating liquid polymers, said system 15 comprising a mixing loop including a pump means and a premix chamber coupled in fluid communication, means for coupling a water supply to an input of said pump means, and means for coupling a source of unactivated emulsion polymer with said mixing loop.
11. The system of claim 10 wherein said pump means pumps a variable amount of said polymer to said premix chamber thereby providing a control over the concentration of said 20 emulsion polymer in said output rate.
12. The system of claim 11 wherein said control means includes regulating means for regulating the flow of said water into said pump means.
13. The system of claim 13 wherein said control means further includes other regulating means for regulating the amount of activating energy introduced into said emulsion polymer. 25
14. The system of claim 13 wherein said pump means is a derated centrifugal pump having a selected flow rate with an increased level of impeller activity, said system providing a desired continuous output rate of activated polymer while maintaining the activation energy introduced into said polymer and maintaining a net positive suction head in said centrifugal pump thereby preventing a cavitation therein. 30
15. The system of claim 14, and control means for automatically controlling said other regulating means to maintain a desired amount of shear energy which is introduced into said polymer in response to changes in said regulating means.
16. The system of claim 15, and sensor means for sensing the level of activated polymer and for deactivating said system responsive to a sensing of a preselected level of said activated 35 polymer.
17. The system of claim 16, and flow meter means communicating with said mixing loop, and means responsive to said flow meter in conjunction with said regulating means for selecting a desired output of activated polymer.
18. The system of claim 17, and means for automatically deactivating said system in re- 40 sponse to a detection of a low water flow condition.
19. The system of claim 18, and alarm means for warning an operator in response to said low water flow condition.
20. The system of claim 19, and pressure monitoring means for monitoring the pressure in said mixing loop. 45
21. A method of providing a variable rate, continuous output of activated emulsion polymer comprising the steps of simultaneously providing water and an unactivated emulsion polymer in a mixing loop, controlling a mixing pressure introduced into said polymer in said mixing loop by providing a relative large and controlled amount of activation energy at a relatively low volume flow rate, and controlling the amount of water introduced into said mixing loop for controlling 50 the output volume of said activated polymer from said mixing loop.
22. The method of claim 21 wherein the amount of said mixing pressure maintains a desired amount of activation of said polymer and water in said mixing loop to control the amount of activation of said polymer.
23. The method of claim 22 and the steps of controlling the amount of polymer introduced 55 into said mixing loop for controlling the concentration of said polymer.
24. The method of claim 23, and the added step of automatically deactivating said method in response to sensing a predetermined level of output of activated polymer.
25. -The method of claim 24, and the added steps of sensing a low level in the flow of water, and automatically deactivating said method responsive to the sensing of said low flow. 60
26. The method of claim 25, and the added step of warning an operator in response to the sensing of said low after flow condition.
27. A four stage method of activating a polymer, said method comprising the steps of:

(a) premixing water and a polymer in a mixing manifold containing a static mixer; (b) blending the out put of said manifold in a pump having a substantial blade activity relative 65 8 GB 2 192 806A 8 to volume of out flow; (c) recycling a substantial portion of the outflow of said pump through said mixing manifold, and (d) directing the remaining portion of the outflow of said pump through a pressure regulator with a sudden and abrupt relaxation of the pressure imparted by said pump. 5 Published 1988 at The Patent Office, State House, 66/71 High Holborn, London WC 1 R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.

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