Optimizing Waste Water Aeration System-Challenges & Solutions

2. ● An Aeration system
● Current Aeration process control techniques
● Challenges in Aeration process control
● Solutions for Aeration process optimization
● Typical Example of Aeration optimization & Energy saving
● Introduction to the company – LEOMI Instruments Pvt. Ltd.
TOPICS OF WEBINAR
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3. An Aeration system is used to introduce air into the wastewater to create an environment that
promotes the growth of microorganisms to decompose the organic waste. The oxygen feeds or
nourishes microorganisms within the basin, so the bacteria thrive and consume suspended
particulates.
An Aeration system broadly consists of below parts :
• Airflow generation
• Airflow distribution
• Aeration control
AN AERATION SYSTEM
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4. AN AERATION SYSTEM
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5. ● Typically up to 50% of the cost spend on air flow generation by blowers in a wastewater
treatment plant
● Efficient Air Blower selection is of prime importance.
AIR FLOW GENERATION
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6. AIR FLOW GENERATION
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● Major factor for selection of efficient blower depends on :
❖ Design type such as Tri-lobe & Twin lobe
❖ Longer life
❖ High reliability
❖ Low maintenance,
❖ Low operating cost
● With the help of an efficient air blower air generated is
introduced into the basin for treatment.
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7. ● With the help of an efficient air blower air generated
is introduced into the basin for treatment.
● Air blowers may feed the main header which serves
multiple aeration basins.
● From the main header, the air flows to each aeration
basin or each zone in an aeration basin.
● Depending on the design, flow meters may be used to
measure the flow to each aeration basin or individual
zones in each basin.
AIR FLOW GENERATION
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8. ● An aeration air flow distribution into the basin is done by Surface aerators (conventional) Or
Diffuser membrane technology
AIR FLOW DISTRIBUTION
DIFFUSER SYSTEM SURFACE AERATION
High DO levels at Lower energy cost Lower DO levels at higher energy
cost
Highly efficient system Low efficient system
Low overall operating cost 3- 4 times more operating cost than
diffuser
Low maintenance downtime High maintenance downtime
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9. ● Diffuser membrane technology is currently widely used for air distribution.
● Important factors in selecting suitable diffuser design for optimum aeration flow :
❖ Material - Silicon, EPDM etc
❖ Sizing
❖ Type - Fine or Coarse
❖ Placement
Tubular Disc
AIR FLOW DISTRIBUTION
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10. AERATION CONTROL
● Online Dissolved Oxygen (DO) monitor is crucial for controlling the oxygen available
to the microbes in an aeration basin.
● Optimum Air flow control is most important to meet the oxygen demand of each
zone while keeping the system pressure as low as possible.
● System should achieve efficient decomposition & saves costly air consumption.
● To monitor air flow rate is important is to ensure a proper balance of air flow to each
zone with respect to Dissolved Oxygen content.
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11. CHALLENGES IN AERATION PROCESS CONTROL
● Optimum selection of Air Blower & Diffuser system
● To measure accurate online dissolved oxygen content
● DO control is a function of Air flow rate NOT the system pressure.
● To measure & control optimum air flow rate based on changing demands
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12. CHALLENGES IN AERATION PROCESS CONTROL
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13. SOLUTIONS FOR AERATION PROCESS OPTIMIZATION
INSERTION THERMAL
MASS FLOWMETER
ONLINE DISSOLVED
OXYGEN SENSOR
DO CONTROL SYSTEM 13

14. INSERTION TYPE
INSERTION THERMAL MASS FLOWMETER FOR AERATION AIR
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15. MEASUREMENT PRINCIPLE
WORKS ON KING’S LAW
• Constant temperature anemometry principle
• Higher the mass flow rate higher the cooling
effect of the heater sensor thus higher the
power required to maintain the differential
temperature constant.
• Heater power consumption is proportional to
mass flow rate
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16. SENSOR GENERAL SPECIFICATIONS
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Rugged stainless
steel sensor probe Flow velocity range from
0.6 to 150 Nm/s
Accuracy ±1.5% reading
or better
Working temperature
up to 400⁰C
16 bar(g) max. operating
pressure or higher on request
IP67
protection

17. SIGNAL EVALUATION GENERAL SPECIFICATIONS
24VDC or 230VAC
power supply options
Outputs : 4-20mA DC / 0-10VDC;
Programmable Pulse or Relay (1 NO/NC)
Large LCD display
Built-in thermal conductivity
compensation of air
Communication: RS-232,
RS-485 Modbus RTU;
Ethernet; HART Compatible;
Profibus
Drift free digitally controlled
heater temperature design
Enclosure : IP65 /
IP66 / IP67
Terminal
software pack
with In-built
data-logging
Up to 4 analogue inputs
can be configured 17

18. LEOMI-586 SENSOR INSTALLATION RECOMMENDATION
Recommended
Recommended for
high moisture pipes
X
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19. ½” Nipple & ½” Full
port valve
Probe Insertion with safety chain
in pressurised pipe
Probe with Ball
Valve Assembly
INSTALLATION IN PRESSURED LINE
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20. NO PRESSURE DROP :
• ~3-10 mmwc across operating ranges
• whereas DP Type may have 50 mmwc -1000mmwc in aeration blower
• Approx. 8 – 15 % power saving typically against DP Type
HIGHEST TURN-DOWN RATIO :
• Typically 100 : 1 Turn-down ratio proves to be most sensitive.
• Whereas Pitot or Orifice DP Type 4:1
• High measurement sensitive high signal resolution for fine analysis than
Orifice, Aerofoil, Pitot Tube.
NO
CHANGE
IN
PIPE
DIAMETER
INSERTION THERMAL MASS FLOWMETER AN IDEAL FOR AERATION AIR FLOW CONTROL
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21. HIGHEST ACCURACY :
• Direct Mass Flow Measurement whereas DP are Volumetric
• >±2.0% of reading better than most of Orifice or Pitot DP Type
• With instantaneous thermal conductivity correction of air
LOW TOTEX ( TOTAL EXPENDITURE = CAPITAL + RECURRING ) COST :
• Installation needs <2 hours with planned shutdown whereas DP
needs higher time around a day & higher installation cost.
• Virtually NO Maintenance as work same as Pt-100 Temperature
Sensor
• NO Shutdown required for preventive maintenance whereas Other
Vortex needs shutdown.
MAIN BENEFITS AGAINST OTHER FLOW TECHNOLOGIES
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22. ADJUSTABLE DESIGN :
• Insertion Type is adjustable & with programmable pipe diameters
whereas Inline type are for specified pipe size.
• Programmable gas other than air is possible
CLEANABLE SENSORS :
• Can be cleaned by compressed air or by recommended liquid
solutions after removal from measuring stream for routine
maintenance & provides repeatable reading all the time.
• Whereas DP Type ports get clogging.
LEOMI 586 MAIN BENEFITS AGAINST OTHER FLOW TECHNOLOGIES
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23. Works excellent in Dry and Wet Aeration Air
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LEOMI 586 MAIN BENEFITS AGAINST OTHER FLOW TECHNOLOGIES

24. ONLINE DISSOLVED OXYGEN SENSOR
OxySense Sensor
● Lumiphore Optical Dissolved Oxygen
● 0-50mg/l or 0-500% Saturation
● Submersion mounting - Ideal for unpressurised
applications
● Air or water purging provides self cleaning and
sensor verification
● Results in up to ZERO maintenance/calibration
between yearly sensor calibrations
Sensor body
Sensor cap
Thermistor
Supplied by MTS
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25. DO CONTROL SYSTEM
DO CONTROL SYSTEM
● Works upto max. 4 analog input such as DO,pH,TSS etc*
● Multiple analog output, Digital inputs & relay output available
● Available with MQTT protocol; Modbus: Profibus compatible
● Industry 4.0 ready
● Remote internet access & control
* (expandable upto 16 sensors)
Supplied by MTS
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26. BENEFITS OF FLOW CONTROL IN AERATION SYSTEM
• Approx. 20% Energy saving for medium to large WWTP. (Approx.50 KWH-100 KWH
saving for per 3.5 million litres treated* )
• DO is not a function of system pressure. DO control requires control of air flow only.
• Excess Pressure Simply Waste Power.
• Use of direct flow control with cascade control with the help MOV (most open valve)
logic can give the best process control & reduce pressure and power consumption.
• The most open valve (MOV) control strategy attempts to optimize blower and valve
adjustments by ensuring that the valve serving the zone or basin with the highest air
demand is full open.
(*internet source)
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27. Optimisation of the oxygen concentration
• Even very small changes of the sewage level in the aeration tank or of the aerator condition
cause significant changes of the pressure conditions in the compressed-air piping.
• The air diffusion of the plant is thus permanently exposed to partially strong variations.
• Therefore, the regulation of the aeration according to the oxygen concentration is too slow for a
consumption-optimised regulation.
• The O2-concentration responds to the actually delivered air quantity only with a delay.
• Therefore, the O2-concentration varies continuously around the set-point value. This has
negative effects on the power consumption and the cleaning process.
• Leomi 586, however, continuously monitors the delivery of air and thus responds immediately to
the smallest hydraulic changes.
• Thereby, Leomi-586 ensures a constant oxygen concentration and consequently an optimised
process.
TYPICAL OPTIMIZATION AND SAVING BY AERATION PROCESS CONTROL
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28. TYPICAL OPTIMIZATION AND SAVING WITH AERATION PROCESS CONTROL
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29. Economic from installation to operation*
• Saves energy costs over the whole investment period.
• The low pressure drop also saves energy costs.
• The high control quality and measuring accuracy of Leomi -586 ensures optimum
process operations, i.e. the optimisation of the decomposition performance and
consequently the observation of the limit values during the process and, at the same
time, prevents costly waste of compressed air.
• The maintenance efforts are practically non-existent, the components used have a long
life.
TYPICAL OPTIMIZATION AND SAVING BY AERATION PROCESS CONTROL
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30. TYPICAL OPTIMIZATION AND SAVING BY AERATION PROCESS CONTROL
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31. ABOUT LEOMI INSTRUMENTS
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ISO 9001:2015
company
German Technology
Transfer in India
“OPTIMIZING LIFE” Central
idea for product & solutions
development
India’s first fully automatic
wind-tunnel calibration
facility
20+ year’s worldwide
proven product
LEOMI @GANDHINAGAR
GIDC,GUJARAT, INDIA
recognised
Mr. Frank Mohns as a
Technical advisor for product
development.
MTS Engineers Pvt.
Ltd group promoted
company

32. INSTALLATION IN WASTEWATER AERATION BASIN
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33. E-17/5, Electronic GIDC,
Sector-26,Gandhinagar-382027,
Gujarat, INDIA
+91 79 23287899
sales@leomi.in
www.leomi.in
• .