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Where Polymer is Used and Why. Hayward Gordon Ltd. Chem Systems Division. North American Sales Meeting Monday April 25, 2005. Presented By: Peter Serwotka. Some Definitions. POLYMER - A long chain molecule formed by the union of many monomers.
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Where Polymer is Used and Why Hayward Gordon Ltd.Chem Systems Division North American Sales Meeting Monday April 25, 2005 Presented By: Peter Serwotka
Some Definitions • POLYMER - A long chain molecule formed by the union of many monomers. • MONOMER - A molecule of low molecular weight capable of reacting with identical or different monomers to form polymers. • IONIC - Refers to either a positive “cationic” (+) or negative “anionic” (-) electrical charge treatment put onto the polymer. • ORGANIC – A substance that comes from animal or plant sources (carbon based). A polymer can be either organic or inorganic.
Why are Polymers Used?(in water treatment) • Contain ionizable functional groups and are water-soluble. • Provides the charge neutralization necessary for coagulation. • Many different polymer variations are available which can be specifically tailored to the process.
+ + + + + What is a Polymer? Monomer Homopolymer Copolymer Chemical Substitution
Examples of Monomers CH3 CH2 CH C CH2 C = O C=O O - n O- Polyacrylate n Polymethacrylate CH2 CH CH CH2 C = O C = O OH NH2 n Acrylate – Acrylamide Copolymer
-[- CH2 - CH -]- C = O CH3 + NH - CH2 - N CH3 Dimethyl-aminomethyl-acrylamide Monomer + + + + + + + + Example - Mannich Polymer High Cationic Charge 3D Structure
Example - Mannich PolymerPhysical Properties High Viscosity Solution Polymer DIMAM Acrylamide (tertiary amine substitution)
Demineralizers Dust Control Influent Clarification Condensate Res-Q Smelt Spouts Boiler Feedwater Reverse Osmosis Color Removal Waste Clarifier Cooling Towers Mill Supply Corrosion Dewatering Closed cooling OPPORTUNITIES!!! Dissolving Tank Vent Scrubbers Foam Control Bioaugmentation Boiler Internal Non-condensible gas scrubber Ash Sluice Systems Softeners Bark Boiler Scrubbers Boiler Fireside Mill Supply Biological Condensate Polishers Coal Flow Aids
Raw / River # 1 Pulsator Wire Screen # 2 Pulsator Demineralizers Sand Filters Water Reservoir Filter Backwash # 3 Pulsator Bar Screen Cooling Towers # 4 Pulsator Others # 5 Pulsator Traveling Screen Anionic Polymer Chlorine Chlorine Clearwell Coagulant To Potable System Influent Water Treatment Flash Mixer
Unit Operations in Water Treatment • Clarification / Filtration • Disinfection • Coagulation • Flocculation • Sedimentation • Filtration
Purpose of Coagulation • Aids in the settling and separation of suspended particulate matter • Removal of color and turbidity from the water • Functions by charge neutralization and by forming insoluble hydrolized precipitates that entrap and settle with particles
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Coagulation Process Charge Neutralization Similar Charged Particles Repel Each Other Coagulant Polymer + + + + + + + + + + + + + + + + + + + + + + + + + + +
Coagulants • IC: Inorganic Coagulants Salts of aluminum or iron (alum, PAC or ferric salts) • PC: Polymeric Coagulants Organic - water soluble cationic polymers • polyamines, DADMAC, Mannich • CDP: Custom Designed Blends of organic and inorganic coagulants
Organic Coagulant Characteristics • Low molecular weight cationicpolymers • Almost always supplied as a “neat” solution. • Often very high charge substitutions • Usage rate at 2- 25 ppm • Typically a dilution pump skid is all the equipment that is necessary. • Relatively low viscosity compared to flocculants
Dual Progressive Cavity (dilution) Skid • Typical coagulant polymer pump skid. • Progressive cavity most common style of pump • Variable speed for controlled metering of neat polymer solution • Adjustable dilution water with in-line mixing
Unit Operations in Water Treatment • Clarification / Filtration • Disinfection • Coagulation • Flocculation • Sedimentation • Filtration
Influent Water Treatment Locations FLOCCULANT CHLORINATION TREATMENT COAGULANT CLARIFIER CLEARWELL TO PROCESS SLUDGE RIVER
Flocculation • Process is achieved with a high molecular weight cationic or anionic polymer, typically a polyacrylamide (PAM). • Further agglomerates the destabilized (coagulated) particulate • Enhances settling by making particles larger • Application dosages 0.2 to 0.5 ppm • Added after coagulation - to center well of clarifier • Accomplished with either emulsion or dry powder polymer products
Two Primary Forms of Flocculants Dry Polymers • Conveying • Wetting • Dust handling • 60 mins aging Liquid Emulsion Polymers • Inversion (Breaking) • Mixing • Hydration (Aging) • 20 mins aging
POLYMER WATER OIL Emulsion – What is it??
Inversion or Activation + + + + + + + + + + + + + + + + + + + + + + + + + + + + + BEFORE AFTER
WATER MIXING AGING/ HYDRATION LIQUID POLYMER Tote or Drum METERING AND ACTIVATION AGING/ HYDRATION/ RUN TANK (AGITATION OPTIONAL) PUMPING DELIVERY Key Elements of a Liquid Emulsion Polymer System
Emulsion Polymer System • Activator Series • For emulsion polymers • Accurate metering of neat emulsion • Inverts polymer from oil phase to water phase in “Activation Loop” • Dilutes neat product with water to final concentration
Key Elements of a Dry Polymer System AGITATOR OPTIONAL POLYMER WATER TO PROCESS CONVEYING WETTING MIXING AGING RUN TANK DELIVERY HANDLING AND METERING PUMPING
Dry Polymer Systems • ChemVac System • Dry cationic or anionic powders • Wetting out is accomplished with unique mixing head assembly • Aging of polymer is required • Typical of larger installations
Typical Waste Treatment Plant To Primary Secondary Biobasin River Clarifier Clarifier Return Activated Sludge (RAS) Primary Waste Activated Sludge (WAS) Sludge POLYMER POLYMER Sludge Rotary Screen FKC Screw Blend Tank Thickener Press b Pressate Bunker Collection Tank
POWDER Vacuum WATER MIXING AND WETTING ZONE ChemVac Mixer Assembly
Polymer Product Summary • CI inorganic cationic • CL liquid cationic • AE anionic emulsion • CE cationic emulsion • AP anionic powder • CP cationic powder
Polymer System Makedown Requirements • Dilution is recommended but not required. These polymers may be fed neat to areas with extremely good mixing • No lower limits exist. Determine by evaluating tank size and pump capacity • With automatic makedown units, emulsion polymers need 15-30 min aging time. Additional mixing is recommended but not required. No aging or additional mixing is necessary for clarification applications. • Data not available