Providing answers to the wastewater aeration market

12 Pages·2009·0.42 MB·English

Providing answers to the wastewater
aeration market
Air compression solutions
Answers for energy.
Providing customized products and
integrated solutions from one single source
Environmental focus With our overall strategic focus on the
By supplying the precise amount of clean development and manufacturing of
air in a very efficient and optimized way, equipment and solutions that provide
Siemens is contributing to obtain your efficient and high quality products, we
environmental targets. We support you define the industry standard.
in achieving low sound emissions, increa-
sing water quality output, and reducing Enabling solutions
your carbon footprint. Our team will We offer our customers standard and
accomplish this while keeping a focus customized products and integrated
on your required process conditions solutions from a single source. Siemens
and demands. not only supplies aeration blowers, but
works with the customer to create the
Experience most optimized aeration process. Our
In this specific application, Siemens has team of engineering specialists, biological
a 30-year successful history in over 60 experts, and committed manufacturing
countries worldwide. With more than technicians work closely together to
7,000 units installed globally, Siemens create the best possible solution suited
leads the aeration compression market to your process needs.
in wastewater.
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Our ecological balance sheet with
7,000 installed references:
We reduced the energy demand of
the industry by 675 MW (equivalent to
a 1 billion Euro power plant).
This accounts for over 430 million Euros
per year in energy savings for the
wastewater treatment industry.
Our installed products and solutions
achieve emission savings of over
2.9 megatons of CO per year
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(equivalent number of cars on the
road: 750,000).
A plant’s aeration
process can typically Siemens provides
consume 50% of its you with:
energy usage
Customized or standard single-stage turbo
compressor packages
Auxiliary equipment needed to optimize operation
of the primary components and systems
Energy efficiency
The demand for sustainable energy usage The instrumentation, sensors, monitoring and
is driving the search for the most optimized control systems that are crucial in optimizing
treatment processes. Siemens’ energy- operation of the entire aeration installation
focused product portfolio is specially Complete, fully integrated aeration solutions,
designed to meet this challenge. Our target along with cost-effective service contracts to
is to enable our customers to increase ensure minimum life-cycle cost
energy efficiency, thereby decreasing
the energy bill while contributing to
environmental and climate protection.
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Improving your operational efficiency
To better understand and manage the For a typical wastewater treatment
costs of investments, many organizations plant, the vast majority of the operating
analyze the total cost of ownership over expenses are energy cost, the minority
the equipment’s entire life cycle. This being maintenance costs. So a decrease in
creates a comprehensive overview of total life-cycle costs should be centered
direct and indirect costs, and presents on reducing the operating expenses.
a true comparison between different Considering that the aeration process
offerings in the market. can typically consume 50% of its total
energy consumption, aeration efficiency
Focusing on the areas of improvements are the most impactful
greatest saving potential step to reduce your electricity bill.
Focusing on the areas with the greatest
In general, wastewater treatment plants potential for improvement will yield the
and their respective aeration equipment greatest savings.
have a minimum life span of 20 years.
Less than 10% of the life-cycle costs
or total cost of ownership during this
period consists of capital cost, while
upwards of 90% are costs relating to
operating expenses.
Life cycle costs
10% capital costs
90% total operating costs
(20 years)
Operating costs
3–5% maintenance costs
(20 years)
95–97% energy costs
(20 years)
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We study your aeration process
Our ecological balance sheet with
7,000 installed references:
Siemens can help you focus on energy
savings by carrying out case studies on
Wastewater of over 600 million PE
the wastewater treatment plant. The
(population Equivalent) is treated with
case study compares the current set-up
Siemens compressor equipment.
of the plant with an alternative configu-
ration calculated by our experts. This Over 300 million people are benefiting from
comparison provides estimated figures environmentally friendly wastewater aeration
on potential savings, optimized process with Siemens equipment.
conditions, and new solutions, which can Every year we supply or upgrade an
be implemented at the plant. Furthermore, additional 45 million population equivalent
it gives you insights into the required of wastewater plants.
financial needs and payback period. From development and manufacture to
disposal, our products comply with all major
Following are two case-study summaries environmental standards. Siemens has strong
of wastewater treatment plants, each internal commitments to reduce its own
of which gained significant savings by carbon footprint. Our goal is to achieve a 20%
implementing high-efficiency single-stage increase in energy efficiency between 2006
centrifugal blowers and automated aeration and 2011.
system control.
Dillman Road WWTP, Bloomington, Granollers WWTP,
Indiana, US Catalonia, Spain
57,000 m3/day two-stage activated Treatment plant capable of treating
sludge, built in 1982, aeration industrial and domestic wastewater
improvements in 2002 A capacity of 30,000 m3/day, sufficient to
Energy cost = $0,0373/kW – cost has meet requirements for 200,000 people
increased since project completion Upgrade to Siemens compressors and
in 2002 Air Biological Control (ABC)
Annual savings of $119,000 (2002 energy After 12 months of continuous operation,
price level) – 15 yr. Savings $1,785,000 overall performance exceeds expectations
Upgrade of new fine-bubble diffusers, Compressors providing faultless
and new single-stage turbo compressors operation and achieving energy savings
with dual-point control. of approximately 30%.
3–5% maintenance costs
(20 years)
95–97% energy costs
(20 years)
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Making the right choice
Select the right aeration Oxygen transfer efficiency depends on
method many factors, including diffuser type,
air flow rate, and depth of submersion.
Control of the active sludge process is Different diffuser types have been
important in order to maintain a high developed, with strong focus on reliability,
treatment level under a wide range of energy efficiency, and easy maintenance.
operating conditions. One of the key
factors for aeration process control is Fine-bubble diffusers have high oxygen
maintaining the defined dissolved transfer and energy efficiency. Coarse-
oxygen levels in the aeration tanks. bubble diffusers are more economical,
and require less maintenance, but have a
Basically there are two methods for lower oxygen transfer efficiency.
aeration of wastewater:
Select the right aeration source
Surface aeration: Mechanically agita-
ting the water to promote solution of The total energy efficiency of the aeration
air from the atmosphere; process is also strongly dependent on the
selected blower type. There are several
Bottom diffused aeration: Oxygen
blower technologies available:
transfer through submerged diffusers
or other aerator devices
Positive displacement compressors,
PD blowers, (Efficiency is low.)
There are several criteria to consider when
selecting the right aeration technology. Multi stage compressors
Energy efficiency is one of the most impor- (The efficiency is relatively low.)
tant, followed by the system’s mixing Single-stage turbo compressors
abilities, with significant differences (Highest possible efficiency)
between mechanical aerators compared to » Direct-driven
diffused aerators. Generally said, surface- » Integrally geared
aerated basins do not achieve the same
performance level as bottom aeration.
The combination counts: highest energy efficiency can be achieved by using
centrifugal turbo compressors and fine bubble diffusers.
References:
Environmenal Dynamics Inc. Aeration method Oxygen transfer efficiency (kg O2/kWh)
Technical Bulletin 127. Energy
consumption and typical Single-stage turbocompressors
performance of various types Fine bubble diffusors 2.8 – 4.0
of aeration equipment. Aeration Coarse bubble diffusors 1.9 – 3.2
systems.
Mueller J.A., Boyle W.C., Pöpel H.J. PD blowers
(2002) Aeration: principles and Fine bubble diffusors 2.5 – 3.1
practice. CRC press
Coarse bubble diffusors 1.5 – 2.1
Vesilind P.A. (2004) Wastewater
treatment plant design. IWA
Pure oxygen 1.0
publishing
Surface aeration
Disk aerators 1.5 – 2.1
Brush aerators 0.9 – 2.0
Multi-stage oxygen transfer efficiency is generally in-between the low and High-end examples
stated above.
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Comprehensive product range of air blowers Main features:
Variable flow with a turn
down from 100 to 45% at
constant speed
2.25
Electric motor drive
ar) Low operation costs due to
b
e ( 1.75 STC-GO Product Range state of the art efficiency
pressur GO (3) GO (7) GO (12) GO (18) GO (32) GO (45) GO (70) GO (90) iLno tnhge l itfoet atilm reegulation range
al 1.25 TC- TC- TC- TC- TC- TC- TC- TC- Minimum maintenance costs
nti S S S S S S S S Compact design and
e
r
fe Direct drive product easy installation
Dif 0.75 range STC-SO Guaranteed oil free air delivery
0.25
1,000 10,000 100,000
Flow actual (m³/h)
Single-stage blower assembly
Blow-off butterflyvalve Air discharge check valve
Blow-off valve silencer Discharge piping (not by Siemens)
Discharge cone/silencer
Discharge expansion joint
Linear actuator, one for each Air blower
inlet guide vanes & variable
diffuser vanes Inlet joint band
Inlet filter/silencer
Coupling and safety guard
Two-stage inlet filter
Local control panel
Electric drive motor
Lube oil air/oil cooler
Vibration isolator
Gearbox-integral with blower
Skid base lube oil reservoir (internal)
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Choosing Siemens single-stage
centrifugal compressors
Within the single-stage centrifugal Optimized aerodynamic and
compressor family, Siemens offers two mechanical design
mechanically different designs for
wastewater treatment: The aerodynamic design is determined by
three core elements:
Integrally geared single-stage
centrifugal compressor: Design Impeller, which is machined from
consists of a gearbox fully integrated a solid forged piece of high-grade
in the compressor. aluminum alloy.
Direct-drive single-stage centrifugal Flow control by variable diffuser
compressor: This blower design uses a system by adjusting the nozzle area
high-speed motor, which eliminates the of a number of diffuser vanes, arranged
need for a gearbox, with the impeller radially around the impeller.
mounted directly onto the motor shaft.
Head control by variable inlet guide
vanes or variable speed, controlling
the speed vector of the airflow to the
impeller.
The Dual Point Control® flow and energy
optimizing system combines the flow- and
head control to meet the flow requirement
at a constant high efficiency.
Overlapping of blowers A, B, C
400 Cascade control
The compressor regulation
n 300 range from 45 to 100%
o
pti enables regulation of two
m
or more units.
u
s
n 200
o
c
er With two compressors it is
w
o possible to regulate the flow
P
100 stepless without gaps from
45 to 200%, with three from
45 to 300% etc.
0
0 100 200 300
Capacity
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Control systems
Siemens offers a wide range of specialized
control systems for fully automatic and
energy-saving operation of the compressor
station. The systems consist of the follow-
ing panels:
LCP Panel MCP Panel
The Local Control Panel is designed for The Master Control Panel controls the
fully automated monitoring and control of oxidation-air supply to the aeration
each compressor. The panel is equipped system, most commonly utilizing the
with the industry-standard Siemens PLC, cascade control. As an option, the MCP
working with an in-house developed can be equipped with an ABC function,
dedicated program, adapted for each which fully integrates the plant air
compressor. The Dual Point Control is control system.
realized by real-time data-sampling and
calculation, whereby the highest possible
compressor efficiency is achieved at all
operational conditions.
Air Bio Control System (ABC)
Main air header pressure transmitter Air flow control valve
to aeration basins
Main air header blow-off valve & silencer
Discharge check valve Manual air control valve
Blow-off butterfly valve & silencer Dissolved oxygon probes
Fine bubble diffusers
Air flow meters
Inlet filter/
silencer assembly
Air flow meters
Single-stage blower assembly
Master control panel
Local control panel
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Providing services and solutions
A global network of support All parts for Siemens Turbomachinery
Equipment compressors, from bearings
Our business unit can rely on a network of and gaskets to impellers and casings, are
selected representatives in more than 30 available through the global Siemens
different markets worldwide, combined Customer Service network. Delivery
with a vast organization of Siemens local takes place either from stock or directly
entities in over 130 countries. This support from our optimized production process,
structure is ready to meet your needs for ensuring the best possible time of
exceptionally efficient aeration solutions, delivery.
customized to meet your individual
requirements, right down to the last Putting energy savings
detail. We provide the air power that back into your production –
gives you air control. our financial solution
Our dedicated aftermarket service team Obtaining funding for wastewater projects
consists of highly qualified experts, who is often one of the main hurdles to over-
offer the full service portfolio from: come when looking at implementing plant
improvements or purchasing new equip-
Installation & commissioning ment. However, as energy conservation
Spare parts grows more important, an increasing
On-site or classroom training number of innovative funding oppor
of your staff tunities are available. In cooperation with
Siemens Financial Services (SFS), we can
Maintenance contracts
offer you a customized financial program
Scheduled maintenance
to match your financial needs with the
and troubleshooting
following advantages
Refurbishment and upgrades of
your older machines
Avoiding upfront investments, hence
Replacement of energy- not burdening your credit line
inefficient equipment
Saving liquidity in turbulent times to
Footprint replacements stay financially flexible
Enjoying cost savings and contributing
to environmental sustainability
Optimized automation solutions
Siemens provides complete air-supply
automation systems for wastewater
treatment plants, thus ensuring effective
integration of the aeration process with
other downstream processes in the plant.
This enables full end-to-end control,
avoiding bottlenecks, and boosting
efficiency at every stage.
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