污水厂中的搅拌器p.ppt

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,Mixing in WWTP,Mixing Duties,What is the job of the mixer in WWTP?,What is the reason mixing is needed?,?,Prevent settling of solids in a liquid,Keep the bottom free from sediments,Keep the solids in a,homogeneous,suspension,Mixing Duty:,Suspension,Drawdown of solids from surface,e.g.Particles lighter than the liquid,Mixing of miscible liquids/Elimination of concentration differences,Specified degree of homogeneity,Specified mixing time,Mixing Inflow,Batch Mixing,Mixing Duty:,Blending,Transport of liquid&matter,Liquid transport into and out of aerated zones,Mixing Duty:,Circulation,Mixing Duties in WWTP,Sand grits,Control level of suspension,Keep sludge in suspension,Allow sand to settle,Mechanical Treatment,Equalisation&Retention basins,Keep solids in Suspension,Intake pump station/Lifting station,Keep bottom clean,Draw-down of floating waste,Intake to WWTP,Mixing Duties in WWTP,Biological Treatment,Anaerobic zones,Keep activated sludge in suspension,Mix inflow,Anoxic zones,Keep activated sludge in suspension,Mix inflow,Mixing Duties in WWTP,Biological Treatment,Aerated tanks,Keep activated sludge in suspension,Circulate liquid over aerated zones,SBR(Sequence Batch Reactors),Mixers and aeration work alternating,Keep activated sludge in suspension,Mix inflow,Mixing Duties in WWTP,Flash mixing,Mixing chemicals into sludge,Given homogeneity and time,Chemical Treatment,Floc mixing,Suspension,Gently circulation to achieve flocculation,Mixing Duties in WWTP,Sludge Treatment/Handling,Mixing/collecting tanks,Mixing inflows,Keep sludge homogeneous,Digesters,Keep sludge homogeneous,Thickening/Storage tanks,Keep sludge homogeneous,The Products:Flygt Mixers,“,Banana blade”mixers,“,Compact”mixers,Compact mixers,Compact Stainless steel design,Small/medium size diameters,Direct driven(multi-pole),Flexible installation on Guide bars,Easy accessible for inspection&service,Suitable for,all tank shapes and sizes,4600-series,4610,4620,4630,4640,4650,4660,4670,4680,Banana Blade Mixers,Large diameter&slow speed,Gear driven,Superior efficiency=Low power consumption,Corrosion resistant coating,Guide bars installation,Suitable for,larger tanks of all shapes,4410/4430-series,4410,4430,Installation Systems,Single Guidebar system,The most commonly used.,Allows very flexible positioning for almost any tank.,The mixer can either be,hanging on a chain or wire,resting on a support beam,Lifting davits are available.,Installation Systems,Tripod Guidebar system,Mainly for the banana blade mixers,where the torsion loads are greater.,Can also be used for the 4600 series.,Double Guidebar system,Specially designed for the banana blade mixers.,Installation Systems,Cantilever system,Can be used for the 4610 and 4620 mixers.Are available up to 3 m length.,Bottom mounting system,Can be used for the 4610 and 4620 mixers.,Using Flygt Mixers in WWTP,Anoxic zones,Aerated tanks,Sludge Handling/Storage,Anoxic Zones,No aeration equipment in tank,Mixing is needed for:,Suspension,Mixing inflows,Common tank shapes,Anoxic Zones for BNR,O,2,Return Activated Sludge,Internal Re-circulation,Waste Activated Sludge,Inflow,Anoxic zone,Aerobic zone,Sedimentation,BNR-Biological Nitrogen Removal,Anoxic Zones,-Selecting Mixers,Tanks Size and Shape,Volume to mix,Losses due to geometry,Keep sludge in Suspension,Mix inflows,Mixing Requirements,+,=,Required,Performance,(Thrust N),?,?,?,Customer Preferences,Investment,LCC,Operation&Maintenance,+,Anoxic Zones,-Selecting Mixers,Example 1:,Anoxic zone-,Small,rectangular tank,10 m,6 m,3 m,SR4410,Prop.=1.8m&18 rpm P,cons,=0.6 kW,SR4630,Prop.=7(w.Jetring)P,cons,=1.3 kW,A simplified LCC:,Investment+Energy cost over 5 years,Anoxic Zones,-Selecting Mixers,20 m,10 m,6 m,SR4410,Prop.=2.2m&25 rpm P,cons,=1.4 kW,SR4650,Prop.=7(w.Jetring)P,cons,=4.8 kW,A simplified LCC:,Investment+Energy cost over 5 years,Example 2:,Anoxic zone-,Large,rectangular tank,Aerated Tanks,Aeration equipment cover part or all of tank bottom.,Mixing is needed for:,Suspension,circulation,Common tank shapes,Aerated Tanks,Partial bottom coverage,Suspension,Circulation of liquid over aerated areas,Full bottom coverage(SBR),Suspension when aeration is turned off,Mixers&Aeration never operate at the same time,Aerated Tanks,-Selecting Mixers,Example:,Racetrack with bottom diffusers,2 x SR4430,Prop.=2.5m&35 rpm P,cons,=6.9 kW(tot),2 x SR4660,Prop.=15(w.Jetring)P,cons,=18.9 kW(tot),Sizing is based on:,Size&geometry of tank,Aeration,Required velocity,Investment+Energy cost over 5 years,Aerated Tanks,-Selecting Mixers,Large tanks,Energy efficient,Large volume Circulation,Smaller tanks,When installation might be difficult,Sludge Handling/Storage,Sludge with DS 1%,up to 10-15%,Mixing is needed for:,Mixing inflows,Prevent stagnant areas,keep homogeneous,Common tank shapes,Sludge characteristics,High concentration,High viscosity,Increased power consumption,High“yield stress”,stagnant zones with too small mixers,Mixing Sludge,Too small mixer,stagnant zones,Sludge Handling,-Selecting Mixers,Not suitable for sludge mixing,Larger investment,Lower power consumption,Better cooling of motor at high viscosity,smaller investment,Higher power consumption,Suitable when risk of clogging,Without Jetring,With Jetring,Sludge Handling,-Selecting Mixers,Example:,Storage of thickened sludge,13 m,4 m,6%sludge,SR4660,Prop.=11,without Jetring,P,cons,=9.8 kW,SR4660,Prop.=11,with Jetring,P,cons,=7.2 kW,Investment+Energy cost over 5 years,Pay-Back Jetring=1 Year,Mixers for any demand in WWTP,