Innovation in Energy and Pollution
in
Steam Boilers
Datta Kuvalekar
Shrikant Thombare
Rohit Pimpley
IPPTA Seminar , Ahmedabad
August 6-7th, 2015
Proprietary content © Forbes Marshall
Proprietary content
© Forbes Marshall
The Energy & Environment equation
Energy Efficiency
α
1
______________
Environmental Load
Energy and Environment are not separate buckets but strongly linked !
Proprietary content
© Forbes Marshall
Boilers & Environment load
•
•
•
•
•
Green House Gas emissions ( GHG )
Particulate Matter ( SPM)
CO Emissions
Ash
VoCs
Proprietary content
© Forbes Marshall
It all starts with Energy Efficiency !
• If one reduces process steam demand, then
one is able to impact Fuel consumption.
• Indeed, Boiler efficiency is also to be
optimized.
• kg of fuel per ton of paper produced !
Proprietary content
© Forbes Marshall
Concept of cost conservation curve
Proprietary content
© Forbes Marshall
Many things to do !
• Look at energy efficiency options through the
full cycle.
• It is not just installing a bag filter or a ESP or a
cyclone. Start with the root cause ! The fuel
load !
• Thus start with basics and then with
innovative technologies
Proprietary content
© Forbes Marshall
Principles of Energy minimization
•
Reduce temperature of any exhausts in boiler house
•
Minimize amount of water evaporated in drier section
•
Minimize steam condensed outside driers
•
Maximize condensate return and pressure
•
Minimize electrical consumption of drives/pumps
•
Monitor and manage energy consumption trends & costs.
Proprietary content
© Forbes Marshall
Principles of emissions minimization
First -Reduce the fuel Load of the boiler and
abatement methods!
Optimise combustion conditions on the bed
With optimum air-fuel ratio
Maximise boiler efficiency.
Measure emissions !
Proprietary content
© Forbes Marshall
Trials on Steam Boiler in a paper mill
• Site Details : 21TPH, 15bar, Fuel: Husk or
Husk + Coal)
• External Arresters : Cyclone (6 No) + Bag filter
• Heat Recovery Systems : APH and Economizer
• Point of SPM Measurement : After external
arresters.
• Technique of SPM Measurement : DCEM 2100
(Dust Analyzer)
*All the systems are controlled manually.
Proprietary content
© Forbes Marshall
Trials --- Results
 To assess the variation in SPM levels with change in O2% by controlling
ID/FD/Load
A. Load & FD Fan constant, varying ID Fan:
1. As we vary the ID frequency the SPM will increase with increase in the O2%.
2. The is because as the ID pressure increases, it creates a suction effect. This
causes ash particles to flow with the air thereby increasing SPM levels in stack.
90
6
80
5.9
70
5.8
5.7
5.6
50
5.5
40
5.4
30
5.3
20
5.2
10
SPM
0
O2 %
SPM
60
O2 %
5.1
5
Proprietary content
© Forbes Marshall
Trials --- Results
B. Load & ID Fan Constant, varying FD fan:
1. As we vary FD speed the SPM will decrease with increase in O2%.
2. With increase in FD Speed the increased O2% will give a sudden push to the
system thereby increasing SPM initially.
As the system gets stabilized SPM starts dropping down with increase in O2%.
SPM Vs. O2 @ Varying FD
100
8
6
O2 %
80
SPM
3.
60
40
SPM
O2%
4
Proprietary content
© Forbes Marshall
Trials--- Results
C. At Varying Load Conditions:
1. At the varying load conditions with the increase in O2% the SPM level
decreases.
Load @ 3000 kg/hr.
SPM
the SPM level also will increase,
but when the oxygen level also
50
6
40
5
4
30
3
20
increased proportionally, the
2
10
SPM
0
Load @ 5000 kg/hr.
Load @ 4548 kg/hr.
50
O2 %
150
5.2
5
4.6
125
4.4
O2 %
4.8
SPM
O2 %
3.82
3.8
3.78
3.76
3.74
3.72
3.7
3.68
3.66
3.64
SPM
100
SPM
1
O2 %
0
SPM will depreciate.
O2 %
2. With the increase in the load
4.2
4
100
3.8
SPM
O2
Proprietary content
© Forbes Marshall
Trials --- Results
 To ascertain the optimum oxygen percentage at which the SPM and efficiency
compensated
 In observed case we can define
optimum O2% level @ 7.1 where
SPM was 66 mg/Nm3 & Efficiency
90
8
85
7.5
80
7
75
6.5
70
6
65
5.5
is
increasing
still
the
a
scope
Efficiency
of
by
reducing O2 % up to 4% without
O2 %
 There
SPM & Efficiency
was 67.26%.
crossing SPM limits above 130
mg/Nm3
60
SPM
Effi.
O2 %
5
Proprietary content
© Forbes Marshall
Package Benefits
1. Only by monitoring SPM level & trying it to control by varying O2% level, there
could be backfire if Furnace pressure goes in positive band as shown.
2. Hence with a complete package it is possible to maintain the SPM level, with
boiler safety & optimum Efficiency
Effect on Furnace Pr.
tight control of ID & FD fan
there is considerable drop in
5.15
120
5.1
5.05
100
SPM & Fr. Pr.
speed using Furnace Pr. value,
140
80
4.95
60
4.9
40
4.85
to 8%.)
O2
4.75
0
-20
Fr. Pr.
4.8
+ve Fr. Pr.
20
Unburnts (approx. from 12%
SPM
5
O2 %
3. As per the feedback due to
1
2
3
4
5
6
7
4.7
4.65
Proprietary content
© Forbes Marshall
Insights into Efficiency and SPM
• There is a reduction in the SPM levels when there is an increase on the O2%
and vice-versa.
• The SPM levels decreases only when O2% is controlled by the FD fan speed
but not through ID fan speed.
• Even in the presence of external dust arresters like Cyclone & Bag filter, the
effect of the O2 variation on SPM level was observed.
• Every boiler will have a optimization need for Efficiency and SPM as the
experiment shows the SPM levels vary with variation in load %.
Proprietary content
© Forbes Marshall
Innovations in Energy /Environment
• The BEESAS System .
• The Effimax /SPM system
• The compact ESP and Hybrid Cyclone
• The Drymax system
Proprietary content
© Forbes Marshall
BEESAS Features:-
BOILER EFFICIENCY ENVIRONMENT SAFETY AUTOMATED SYSTEM
Proprietary content
© Forbes Marshall
Control and Automation
•
•
•
•
•
•
•
•
Load based firing control
FD and ID fan control with auto changeover
Deaerator level and pressure control
Fine combustion control
3 element/single element drum level control with auto changeover
Auto blow down control
Integrated boiler start-up
Sequence and normal shut off
BOILER EFFICIENCY ENVIRONMENT SAFETY AUTOMATED SYSTEM
Proprietary content
© Forbes Marshall
Efficiency
• BS845 Efficiency Calculation
• Lesser power consumption with VFD’s for FD, ID, feeder, stoker and feedwater motors
• Boiler Operator Performance Index
• Power consumption tracker
• Air pre-heater/Economizer performance tracker
• Bed temperature monitoring
• Remote monitoring
BOILER EFFICIENCY ENVIRONMENT SAFETY AUTOMATED SYSTEM
Proprietary content
© Forbes Marshall
Safety and Reliability
•
•
•
•
•
Monitoring of all safety parameters
Safety Interlocks
Redundant transmitters and channels with auto changeover
Hot swapping
Watch dog for Instrument Reliability
BOILER EFFICIENCY ENVIRONMENT SAFETY AUTOMATED SYSTEM
Proprietary content
© Forbes Marshall
Environment
•
•
•
•
•
Lower SPM emission
Reduced CO2 Emission
Reduction in CO
Mitigation of climate change
Minimal carbon footprint
BOILER EFFICIENCY ENVIRONMENT SAFETY AUTOMATED SYSTEM
Proprietary content
© Forbes Marshall
Efficiency + Environment
Boiler Efficiency and Environment manager
Proprietary content
© Forbes Marshall
Compact High Efficiency ESP
Attribute
Collection efficiency in
0.1 to 10 Micron range
Handle Exhaust Temp
> 150 C
ESP
MDC
Bag Filter
Very high > 99%
Low < 85%
Very High > 99%
Very Good
Very Good
Poor
Typical Pressure drop
< 50 mm WC
75 – 200 mm WC
500 – 1500 mm WC
Failure rate
Very Low (Multi stage
and Multi field)
Very Low
High
Novel planar charging electrode producing
a 3D charge cloud
75 kV voltage, close spacing resulting in
twice than traditional field strength
Closely spaced collection plates to
enhance collection even at higher velocities
Proprietary content
© Forbes Marshall
More on the compact ESP
Characteristics
Operating Values, kV
Gas Flow m3/h
Gas linear velocity m/s
Flue gas temperature °C
Dust load in raw gas g/m3
Dust load in clean gas mg/m3
Collection efficiency wt %
Pressure drop,
Power consumption,
kWh/1000 m3
Typical Values
10 to 70
500 to 150,000
0.3 to 3
Up to 290
Up to 12
< 100
95 to 99.9
5 mm to 50 mm WC
0.05 to 2
ESP offers clean emission with
operation cost at 1/3rd to 1/6th of an
equivalent bag filter
FM ESP is a fit and forget type with
no moving parts inside
It is compact with 1/3 the length of a
conventional ESP of same capacity
Proprietary content
© Forbes Marshall
Water Mist Cyclone- Smaller boilers
Attribute
Atomizer
nozzles
ESP
Bag
Filter
Efficiency (%)
99.9
95-99
Maintenance Medium Medium
Capital
High
Medium
Expense
ΔP
Medium
High
Wet
Scrubber
Cyclone
(Lapple)
Water
Mist
80-85
Medium
75-90*
Low
95.5**
Low
Low
Low
Low
Medium
Medium
Low
Controlled water injection for slurry free collection of soot
 High efficiency at lower cost compared to bag filters
 Very low water consumption compared to wet scrubbers
Proprietary content
© Forbes Marshall
More on Hybrid Cyclone
Characteristics
Gas Flow m3/h
Flue gas temperature °C
Dust load in raw gas g/m3
Dust load in clean gas mg/m3
Collection efficiency wt %
Pressure drop,
Typical Values
Up to 15,000
Up to 290
Up to 4
< 150
95
75 mm WC
Hybrid cyclones offers the performance of 2
devices in 1 – Cyclone + Scrubber
 Unique spray control and injection methods
allow to collect without making slurry waste
 Suitable for both oil fired and biomass fired
boilers
Proprietary content
© Forbes Marshall
Drymax- Stabilizing SSC
Proprietary content
© Forbes Marshall
Drymax- enabling efficiency
Proprietary content
© Forbes Marshall
Impact of these Innovations
• 10-12 % reduction in fuel bills
• Environment loads reduced to lower than
statutory limits coupled with energy efficiency
• Closer tracking leading to better managed
systems and lower downtime/Safer operation.
Proprietary content
© Forbes Marshall
Establish what the Energy and environment optimal points are for your mill
Proprietary content
© Forbes Marshall
Thankyou
• Thank you all IPPTA delegates !
Proprietary content
© Forbes Marshall