WWOA Conference @ Wisconsin Dells Session D: MIXING --Wednesday, Oct. 7, 2015 How to Reduce the Operating Cost of Your Wastewater Treatment Plant with Efficient Mixing Authors: Ken Neu, MS Environmental / Health Products & Service, LLC Sam Kondo, PhD Star Burst Technology, LLC Contents of Presentation Introduction-various mechanical & high pressure pulsed air mixing Introduction of Low Pressure (plant) Pulsed Air Mixing Benefits of Low Pressure Large Bubble Pulsed Air Mixing Case Study: Ridgeville, IN Star Burst Mixing with Aeration BioP Mixing Demonstration Study @ MMSD South Shore Plant
Waster & Wastewater Treatment Solutions KEN NEU, M.S. ENVIRONMENTAL / HEALTH PRODUCTS & SERVICE PO Box 21 P. O. BOX 101 Richfield, WI 53076 PHILLIPS, WI 54555 Business Cell: 262-628-1300 E-MAIL: ken-ehs@juno.com
Offered by: KEN NEU, M.S. ENVIRONMENTAL / HEALTH PRODUCTS & SERVICE PO Box 21 P. O. BOX 101 Richfield, WI 53076 PHILLIPS, WI 54555 Business Cell: 262-628-1300 E-MAIL: ken-ehs@juno.com
High-speed Mixer
Slow-speed Vertical Mixer
---- Power of Large Bubble Pulsed Air Mixing---- -----Minimum Energy Consumption and Maintenance----- Pulsed Air mixer systems are ideal for wastewater treatment chambers (aerobic, anoxic and anaerobic), sludge storage tanks, open channels, equalization tanks, and digesters, both anaerobic and aerobic. Equally well suited for water treatment applications, such as flocculation basins, disinfection chambers, treated water storage AND for industrial & agricultural mixing applications.
General Concept- Pulsed Bubble Mix Example: Early Version- Star Burst Mixer Effective Mixing Zone - 10 feet for 12 Mixer - 20 feet for BC101 4 to 6 feet /sec 0.5 to 1 feet/sec
Pulse Air Mixing How It Works Harness the power of large bubbles for highly energyefficient complete mixing. Use short, powerful bursts of compressed air or gas (digester, etc.) through engineered mixers. Large bubbles lift liquid with air/gas blending the contents. Creates a VERY powerful upward force as pulsed air bursts are released (less energy to mix than high or low speed mechanical mixers US Dept. of Energy noticed)
Less Electricity Usage - Promoted by US EPA Mixing liquid with Bubble - DOE evaluated Pulsed Air Mixing in 1999 as an - Innovative Technology. - Report title page: below This is a typical installation of Pulsair cited from their website. Three similar Pulsed Air Mixer products All use high-pressure compressed air develo - Pulsair Systems, Inc--1999 - Pulsed Hydraulics, Inc. (PHI)--2004 - EnviroMix, Inc -- 2008
PHI Design/Specifications Every PHI Hydro-Pulse mixing solution is custom designed and engineered to meet the unique requirements of each customer's mixing application. The PHI mixing system uses air supplied by a compressor (blower air cannot be used as the PHI system requires relatively high psi) which creates the source of the Hydro-Pulse. The air then goes through a MAC valve which is contained in a valve enclosure and then through piping to the forming plates which are installed at the bottom of the mixing basin. The amount of air required is determined by the size and shape of the tank, the tank contents, and the number of forming plates installed.
Less Electricity Usage PulsAir, Phi, BioMx - 5 15 HP rotary screw compressor and the reserve tank - Control Panel with solenoid valves, timers, - Floor mounted SS nozzles - SS Piping - Floor mounted nozzles in a tank
(1/6) Less Electricity Usage PulsAir, Phi, BioMx These are a series of pictures of released bubbles from the Pulsair nozzle. 1. SS circular nozzle of Pulsair 2. Compressed air is released by manipulating a timer and a solenoid valve. 3. Some bubbles become 4 in diameter. 4. Some bubbles enlarge to 6 in diameter.
Mixers Toroidal Bubble Mixer Submersible High-speed Mixer 1.84 HP 15.8 HP Pulsed Bubble Mixer Vertical Slow-speed Mixer 7.3 HP 4.2 HP
Intermittent Large Bubble Pulsed Air Mixers the competitors US Department of Energy-1999--Innovative Technology Summary Report Star Burst Technology Indiana 1998 to present Sam Kondo, PhD. developer-inventor of LOW PRESSURE PULSED BUBBLE Geyser Pump-2001 (sold 4500 units from 2001 to 2012) Evolution of LOW PRESSURE PULSED BUBBLE Star Burst Mixer-2012 Pulsair Systems, Inc ----1999 (high pressure pulsed bubble) PHI --State of Washington 2004 (high pressure pulsed bubble) Enviromix South Carolina---2008 (high pressure pulsed bubble)
Mixer Comparison Could it be that Star Burst Low Pressure Mixer may be 75 to 97 % less power cost than a High-Speed Mixer??
Kondo comparison between StarBurst mixer and other bubble mixers (Randall & Randall 2012) Mixing in a tank of 41 ft x 55 ft x 24 ft (404,000 gallons) Effective Diameter of Mixing (EDM) is typically 10 feet. Bubble Mixer x 30: EDM = 10 ft 7.32 HP StarBurst 12 Mixer x 30: EDM = 10 ft 1.6 HP
Kondo comparison between StarBurst mixer and other bubble mixers (Randall & Randall 2012) EDM s of StarBurst Mixer is 10, 17, 21, 26, 31, 36, 38 & 56 feet. StarBurst 18 Mixer x 12: EDM = 10 ft 1.8 HP StarBurst Mixer BC101 x 3 EDM = 21-26 ft 2.2 HP StarBurst Mixer (BC101 x 1, DC101 x 4): EDM = (56ft, 17 ft) 2.3 HP
Low Pressure Pulsed Air - How It Works - Bubble Creation Installed at the bottom of a tank; Low-pressure (facility) air is fed from a blower to the mixer. If water depth is 10 ft., air pressure needed is 4.3 psi. If water depth is 20 ft., air pressure needed is 8.6 psi. Air is accumulated within an air capture cylinder in the mixer until the air level reaches the bottom of the air cylinder; When air/water interface in the cylinder reaches the bottom of the cylinder, the air pocket is broken; -All accumulated air is instantly released from the air cylinder, forced out due to the static pressure of the water. The period of bubble release is very short (< 1/16 second). Air release in a very short time creates a TOROIDAL (rolling circumference)bubble 4 ft. diameter from a 12 mixer.
Low Pressure Advantages Slightly Compressed gas: Air, Nitrogen or Digester Gas Electrical power: limited to the power required to produce the low-pressure gas source (blower) CAN use (low pressure) plant air supply---no SEPARATE COMPRESSOR REQUIRED
Low Pressure Pulsed Bubble Mixing How It Works-- Simple & Easy Control Intensity of the mixing: --Simple-- control the air volume to mixer (hand valve or automated) Interval between bubbles & bubble size are the key features of the low pressure (Star Burst) Mixer Air Pulse production frequency desired is determined based on a number of variables: viscosity of fluid being mixed, flow rate, depth & volume of the basin.
Low Pressure Pulsed Air Mixing Advantages Mixing intensity can be different for each basin, section of a basin, or application using PLANT OR FACILITY AIR. A simple turn of the air control valve (automated or not) changes mixing intensity Typically, these valve settings are set once for optimal performance for each application and not changed unless the operating conditions change.
Star Burst Advantages-Unique Toroidal Bubble A Huge air release in a very short time creates a toroidal vortex bubble 4 feet in diameter from the 12 mixer. The bubble rolls at the periphery & wraps up any filaments or elongated microbe clusters to create a dense microbe mass. Well suited for anoxic/anaerobic/bnr applications due to small surface to large volume ratio of 4 dia. bubble. 4 toroidal vortex bubble is a standard & unique feature of Star Burst mixers.
When air volume is too big, continuous bubbling occurs. Toroidal Vortex CFD by Dr. Jun Hirabayashi http://hirabayashi.wondernotes.jp/2014/09/23/ - The Most Efficient Mixing Energy with the Least Applied Energy Rotation of fluid in toroid Pressure wave of fast moving fluid (20 feet/sec for StarBurst Mixer) Vortex is formed when air volume is proper. Low pressure at the center of Toroidal Vortex
Toroidal Vortex Here s what happens when Ellen learns about toroidal vortex bubbles/rings
Toroidal Vortex Rolling Motion Created by Toroidal Vortex Let s take a closer look at the rolling motion created by a toroidal bubble. Watch the bottle cap as they drop it into the vortex.
Toroidal Vortex The StarBurst Mixer In Action
Star Burst Advantages: Maintenance Simplified Multiple basins; different processes can often be mixed utilizing the same air source: Low Pressure Plant/Facility Air. No moving parts below water level. Low Pressure Plant Air Blower & valves are above water level, allowing quick and easy access. (Automated controls not required, may be added, if desired)
Ridgeville, IN After Renovation Toroidal Bubble Granular Activated Sludge (using Star Burst Mixers) (10 inch transfer pipe from Aeration Tank to Clarifier) Less Maintenance, Faster Settling, Less Chemical for Coagulation
--Granular Activated Sludge--Advantages Granular Activated Sludge can be cultivated as the Star Burst Mixer operates with its unique toroidal bubble rolling action. Benefits of Granular Activated Sludge: Settling velocity of the sludge is increased up to 10 times faster than ordinary AS; Clarifier capacity may be increased with greater settling rates Sludge volume may be decreased due to increased sludge density With BPR, biological P release & uptake occurs as normal and may be enhanced. Granular Activated Sludge stays in suspension in anaerobic zone w/ Star Burst mix Dense solids = less polymer use = cost savings. Conversion to Granular Activated Sludge using Star Burst mixers may be possible in conventional AS systems & aerobic digestion tanks
Advantages Summary Star Burst Low Pressure Pulsed Air Mixer Durable- all PVC engineered construction; worry-free operation Lowest energy & air pressure requirements of all competitors Lower maintenance than all competitors Lowest capital cost of all competitors Enhanced Oxygen Transfer efficiency (OTE) may be possible when pulsed air mixers are used in conjunction with fine bubble aeration. The fine bubbles stay longer in water due to the mixer agitation. Star Burst Mixers replace multiple mechanical mixers or other mixing devices, and their energy and maintenance requirements
Case Study: Ridgeville, IN WWTP 100,000 gpd Extended Aeration Activated Sludge Package Plant The 2008 plant was having difficulty meeting permit. (Very Limited turn-down capability as built vs. 20 yr. design) Renovations were done in early 2014 to improve performance. Some fine bubble diffusers were removed. Star Burst Mixers were added. Result: Plant performance increased. Secondary effect: Energy use-- dramatically reduced.
Ridgeville WWTP, IN Is this system proven in the field? Train 1 Train 2 Raw Sewage A1 A3 A9 A7 A5 Flow Equalization C1 C2 C3 C4 A10 A8 Sludge Holding A6 A4 A2
Case Study: Ridgeville, IN WWTP Number and size of units: Two trains, 50,000 GPD (each) Detention time: 24.6 hrs. Organic Loading: 10.24 lb.-bod/1000 cu ft Type of aeration equipment: Fine Bubble Diffusers Air /blowers: 450 cfm/three, 200 cfm at 5 psi Air required: BOD: 65.4 cfm NH3-N: 12.3 cfm Mixing: 73.3 cfm RAS: 24.0 cfm
Case Study: Ridgeville, IN WWTP Clarifier 2-rectangular dual hopper/each train 12 W c 24 L x 15 SWD Surface Settling Rate: 173.6 [GPD/ft. 2 ] for 0.1 MGD Weir overflow rate = 3061 GPD/lf/tank at 0.3 MGD Peak hourly flow RAS two 3 Closed Bottom Star Burst Pumps/ea. train Aerobic Sludge Holding Tank: Two, one per train: Air supply = 30 cfm/1000 cu, 27.5 cfm/tank
Ridgeville WWTP, IN - BEFORE Ridgeville WWTP Effluent BOD = 25 mg/l Ammonia = 5.0 mg/l
12 and 18 StarBurst Mixer
Ridgeville WWTP, IN - AFTER Ridgeville WWTP Effluent BOD = <4.0 mg/l Ammonia = 0.4 mg/l
High DO Tank - FBD + Mixer Oxygen Transfer Efficiency is enhanced by the combination of fine bubble diffuser + Mixer
Ridgeville, IN After Renovation StarBurst Granular Activated Sludge (10 inch transfer pipe from Aeration Tank to Clarifier) Less Maintenance, Faster Settling, Less Chemical for Coagulation
Case Study: Ridgeville, IN WWTP Treated vs. Raw WW-Observed Microscopic View of Granular Activated Sludge
Quick Settling Sludge 30 Minute Settleometer Here s a short video of our Granular Activated Sludge in a Settleometer
Case Study: Ridgeville, IN WWTP MLSS Settleometer 30 min SVI
Case Study: Ridgeville, IN WWTP Electricity Cost: Before and after Renovation: Extended Aeration Size of Blower [HP] 35 Electricity Cost [$/year] 17,154 Granular Activated Sludge Size of Blower [HP] 8 Electricity Cost [$/year] 3,921 23% After renovation, the operation blower is reduced from 35 HP to less than 8 HP (77% R).
Case Study: Ridgeville, IN WWTP Conclusions: The combined fine bubble WITH Star Burst intermittent mixing: Creates an optimum environment for high treatment levels, Good environment for biological nutrient removal capability, Toroidal Bubble = Granular Activated Sludge & Improved floc settling, Reduction of operating energy as a side benefit, Low maintenance cost-no moving parts below water Reduction of polymer use due to better settling floc.
BioP Mixing Demonstration Study @ MMSD South Shore Wastewater Treatment Facility Aeration Tank # 25 was outfitted with twelve (12) 18 Star Burst Low Pressure Pulsed Air Mixers on June 14, 2015. An anaerobic zone was created of roughly the beginning 50 of a +350 Long aeration channel.
BioP Mixing Demonstration Study @ MMSD South Shore Wastewater Treatment Facility BioP had been successful when aeration was stopped in the initial section of aeration basins. However, solids accumulations occurred in the unaerated section of tanks. Mixing Goals: Maintain MLSS in suspension in the first 47 feet of an aeration basin; no solids accumulation of negative consequence. Maintain dissolved oxygen in anaerobic condition (textbook indicates 0.3 mg/l DO or less). Demonstration Phase 1: June 14-July 25 (1-2 bursts/ min/mixer & 7-8 bursts/min/mixer), drain tank, examine mixers, tank floor, repair air leak. Demonstration Phase 2: August 27 Ongoing (3-5 bursts/min/mixer)
A-O Process for phosphorus removal Phosphorus Release Phosphorus absorption by PAO (Phosphorus Accumulating Organisms)
Plan View
Side View
BioP Mixing Demonstration Study @ MMSD South Shore Wastewater Treatment Facility Twelve (12) Star Burst Mixers Installed: 15 minutes/ mixer w/4 sets-3/8 SS anchor bolts. (< 4 hrs. to install mixers) Mixers DO NOT touch diffuser pipe or diffuser. Star Burst mixer air cylinder captures & releases existing diffuser air. Of 278 Sanitaire Diffusers in 1st aeration grid section, 266 diffusers plugged, 12 diffusers utilized as mixer air source. Transport of mixers to jobsite & installation materials/plugging diffusers was $ 2,500 = $ 208/mixer. (mixer cost, mixer installation & diffuser plugging labor was not included in above cost)
StarBurst Mixer at MMSD
BioP Mixing Demonstration Study @ MMSD South Shore Wastewater Treatment Facility Twelve (12) Star Burst Mixers were installed over existing Sanitaire diffusers on June 14, 2015. Anaerobic zone volume is 160,000 gallons=21,333 cu ft LOW PRESSURE Plant Air is the only mixer air source. Mixer pulsed air rate average for demonstration period 2 from 8/27-9/11 = 4.4 bursts/min = 24.8 CFM @ 6.7 psi
No Baffle Wall between AN and A Zones
Light Weight, Anchored Heavy Weight, not Anchored
Renovation takes a ½ day (1) (2) (3) (4) (5) (6) ( No Cleaning D Drain the Basin Clean the Basin Unused FBD to be plugged (270) Cover the unplugged FBD with the Mixer Anchor the Mixer Fill the tank with water to check air leak Completed!!! No Baffle Wall No Special Air Supply Lines Low Pressure Air
Basin 25 installation and Bio-P
BioP Mixing Demonstration Study @ MMSD South Shore Wastewater Treatment Facility Star Burst mixers in action anaerobic zone-tank #25 Future Goal: Flow adjustments will finetune treatment process. Baffle walls to prevent aerated water backflow into the anaerobic zone may NOT be needed.
Toroidal Vortex for Complete Mixing at Low DO Tank At MMSD s South Shore plant, Basin # 25: Intermittent Toroidal Bubble mixing significantly increased MLSS suspension-----with No settled sludge at the corner of the tank. Toroidal Bubble
DO, ORP and Phosphorus in Basin 25
2 Bursts/min 7 Burst/min SCFM
7 Bursts/min MLSS Complete Mixing!!! Only 2.3% of total air supplied to aeration basin #25 was used for 2500 SCFM anaerobic zone mixing
2 Bursts/min 7 Burst/min MLSS, DO
Sludge Accumulation? Basin 25 with Star Burst Mixers Basin 26 with FBD
Accumulated Sludge at 26 th Basin 40-50% solids contents at the bottom of 26 th Basin
No Sludge Accumulation in 25 th Basin Estimated 3,000 mg/l solids at the bottom of 25 th Basin
BioP Mixing Demonstration Study @ MMSD-SS WWTF- Star Burst Mixer Study Phase 2 (8/27-9/11) Basin #25 Sample Location Ortho-P, mg/l Inf. to basin 25 (PCE) 5.55 # 25 - Anoxic 1 15.37 # 25 - Anoxic 2 10.63 # 25 - Anoxic 3 8.17 Basin End 0.37 Plant Eff. 0.30 Significant P release in Anaerobic zone, average of 7 data sets. Location MLSS, mg/l AN zone- top 5 1873 AN zone-middle 5 1871 AN zone-bottom 5 2035 Ave. 1926 All values +/- 5.6% of Ave = Relatively Well Mixed Vertical Column, average of 7 data sets.
Conclusions Star Burst Low Pressure Mixer Demonstration @ MMSD South Shore WWTF -- Phase 2 (8/27-9/11-7 data sets-): Bio-P release was achieved in the 47 Star Burst Low Pressure Pulsed Air Anaerobic Mixing Zone with: - Ave DO 0.3 mg/l, - Ave ORP -159 mv Despite vigorous aeration in immediate downstream aeration zone, and NO BAFFLE WALL to prevent higher DO water flow back. Star Burst Low Pressure pulsed air flow through mixers: Ave 4.4 bursts/min/mixer in the Anaerobic zone-estimated 35.6 SCFM 0.616 HP, o.029 HP/1000 cu. ft., 0.0039 HP/1000 gal mixing volume
BioP Mixing Demonstration Study @ MMSD SS WWTF Phase 2(8/27-9/11-- 7 data pts-ongoing): Conclusions continued Two types of Aerated Fine Screen on Star Burst mixers worked well without plugging No sludge accumulation in Basin 25 after 6 weeks operation Potential Future Goal: Attempt to optimize air distribution with aeration zone valve adjustment to minimize high DO water flow back to anaerobic zone. If this can be successfully achieved, the expense of (full or partial) baffle wall construction may be avoided or at least reduced.
---Star Burst Products---- Airlift Pumps & Pulsed Air Mixers
Environmental /Health Products & Service Thank You for the opportunity!
Sludge Storage Tank Mixing Blue River Valley School Indiana BC101 Installed in Sludge Tank The size of the sludge holding tank at Blue River Valley School is: 34' 2" (L) x 15'3" (W) x 10' (D). The volume is 39,000 gallons. Airflow used in this unit is 12.8 CFM @ 4.3 psi. The blower power is 1/3 HP. Custom Mixing Designs via Scientific and Biological Innovation
Installation of BC101 Installed with a backhoe BC101 with Extended Exhausts Custom Mixing Designs via Scientific and Biological Innovation
Burst from 18 Mixer Top View
Albany, IN 5 Horsepower Aerator/Mixer-- 2012 Poor Sludge Consistency = Higher Polymer Consumption during Dewatering
Rotary Vane Compressor of ¼ HP
BEFORE and AFTER Starburst Pump 12 hrs after Starburst Pump; Transparency of the clarifier became more than 2 feet Before Starburst Pump secondary clarifier water was turbid and scum was observed
After Starburst Pump installation Scum has disappeared
Before: Clarifier covered by thick scum Dirty effluent due to sludge overflow Underwater structure can be seen through. AFTER: No more floating scum on clarifier Sludge overflow eliminated Clarity of water in clarifier exceeds 1 foot
Star Burst Advantages-Summary Durable, robust engineered construction; worry-free operation Lowest energy & air pressure requirements of all competitors Lower maintenance than all competitors Lowest capital cost of all competitors Enhanced Oxygen Transfer efficiency (OTE) may be possible when Star Burst mixers are used in conjunction with fine bubble aeration. The fine bubbles stay longer in water due to the mixer agitation. Star Burst Mixers replace multiple mechanical mixers or other mixing devices, and their energy and maintenance requirements
Geyser Pump for RAS
Starburst Air-Pulse Mixer / Pump Operating Principal Air (1) Start (2) Air pocket Fill Period < 1 sec Fill Period > 1 min Air Air (3) Ejection Ejection Period <1 to 10 sec (4) Suction Suction Period ~ <1 to 20 sec
Custom Mixing Designs via Scientific and Biological Innovation