Blow Down Heat Recovery

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Overview of Heat Recovery
Boiler Systems and Operating Costs
Factors Effecting Blowdown
Blowdown Heat Recovery “The Energy Tank”
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to effectively manage and reduce their Operating Costs.
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in Steam / Hot Water / Process Cooling applications.
- Defined costs can be used to identify cost effective projects
designed to reduce system operating costs.
Generalized Industry Overview
Of Boiler Plant Costs
Flue Gas:
Direct Loss $
Steam:
Direct Loss $
Cost to Process $
Boiler(s)
Fuel:
Direct
Cost $
Water:
Direct Cost $
Simplified Boiler Plant Operating Cost
As viewed by Capture H2O
Steam
$+++
Flue $
Steam to heat
Boiler Feedwater
Traps
$+++
Fuel $
Condensate $
Boiler(s)
Treated Water /
Energy
Vent $
Vent $
City
Water $
Regen. or
Power $
City Water $
Boiler Feedwater
$++
Treated Water /
Chemicals / Steam
Waste $
Treated
Water $+
Blowdown $
Typically between 1 – 20% of Steam Load.
Effected by Treated Water
Combination of Large Bottom and Small
Surface Blowdown
Energy / Water / Chemicals
BLOWDOWN HEAT RECOVERY (BHR)
Patented Process: Canada No.: 2,414,611 USA No.: 6,938,583
“THE ENERGY TANK”
Trade Name Registered
Blowdown from steam boilers is a necessary function. This
function however releases significant energy from the
Steam Generation Process.
The BHR process effectively recovers essentially all this
energy and routes it back to the boiler feedwater system.
This simplified process reduces Fuel Consumption,
Greenhouse Gas Emissions and Water Usage.
How the Patented BHR Process Saves
Canada Patent No.: 2,414,611 USA Patent No.: 6,938,583
Steam
$+++
Steam to
Feedwater
Reduced
Flue $
$+++
Fuel $
Boiler(s)
Flash Steam
Boiler Feedwater
$++
Vent $
Recovered to
steam going to
Feedwater
City
Water $
Hot Make-up – less steam
Blowdown $
needed to heat feedwater
Typically between 1 – 20% of
Steam Load
Cold Make-up
Treated
Water $+
Cooled by Treated Cold
Make-up Water
City water cooling eliminated
The Patented BHR Process
1) Flash Steam generated due to pressure drop is recovered to
Low Pressure Steam System (steam going to deaerator) or
Atmospheric Water Tank (vented feedwater tank or
condensate receiver).
2) Large Storage section allows for retention time of
remaining blowdown volume for heat recovery to make-up.
Make-up passed through series of stainless steel coils to
recover sensible heat in the hot blowdown water.
3) Due to cooling blowdown water with the make-up, the need
for cooling with City Water before the drain is eliminated.
How is it Different / Better??
1. Simplified straight-forward approach with no moving parts. “The Energy Tank” tm
serves as you Boiler Room blowdown/blow-off vessel. A BHR Energy Tank will
pay for itself in less than 1 year compared to the 100% non-recoverable cost of a
replacement blowdown tank!
2. Captures 100% of all blowdown streams – Large Bottom blowdown, Intermittent
Surface Skim, Level Column blowdown all recovered. Any other process can only
recover Intermittent/Continuous Surface Skim due to size/pressure rating limitations.
3. Due to large “Storage Section” capacity/retention time, “Hit and Miss” potential of
typical Continuous Blowdown Heat Recovery processes is eliminated. Thermal
stresses, “flash steam hot” to “make-up cold”, realized in Continuous Blowdown Heat
Exchanger is eliminated – prolonging life expectancy of heat exchanger.
4. Any repairs or maintenance can be done on-site / in-situ with nothing more than a
set of wrenches. Entire heat exchanger coil system can be removed and re-installed in a
couple of hours.
Standard
Blowdown
Tank
Standard Blowdown
Plus
Continuous Blowdown Heat
Recovery
BHR Process
With
"The Energy Tank" tm
$5,000 - $12,000
$12,000 - $30,000
$5,000 - $40,000
Depressurizes all
blowdown streams
Depressurizes manual/bottom
blowdown
Depressurizes ALL blowdown
streams
Releases steam to
atmosphere
Recovers some flash steam
to Feedwater/deaerator
No flash steam lost to
atmosphere
Consumes city water to
cool blowdown
Consumes city water to cool bottom
blowdown and some
continuous blowdown
No “Hit or Miss” due to
large storage section
residence time
Need to replace every
20 – 30 yrs
“Hit and Miss” process due to
intermittent flows of blowdown
or make-up
No mechanical equipment
to maintain / monitor / fail
Needs a Level Control Device
to maintain level in Flash Pot
(valve or steam trap)
No additional space required.
Fits in same space as standard
blowdown tank
Thermal stress (hot/cold) on
heat exchanger due to
intermittent flow
Does Not consume city water
to cool blowdown streams
Need to repair/replace components
every 12 – 24 months
Heat Exchanger protected from
thermal stresses
Need to replace every
20 – 30 yrs
P
PRV Station to reduce
Steam to less than 7 psig
going to deaerator
Steam to users
BHR-XXHM Flash Steam
outlet line feeding to down-steam
side of PRV, c/w check valve
to prevent backfeeding to
BHR-XXHM
Deaerator
5 - 7 psig
Boiler Feedwater
4-inch Atmopshere
Vent Line
Heated Softened
Make-up to
Deaerator
Blowdown (Timed & Intermittent)
To Flash Chamber on BHR-250HM
Cold Softened
Make-up to
BHR-XXHM
Cold Blowdown
Water to Sewer
BHR-XXHM
"Energy Tank"
Typical Installation of BHR-XXHM
"Energy Tank"
Utilities
Optimized
6399 Olde Drive, Appin, Ontario N0L - 1A0
P/F: 519-289-5246
C: 519-668-8714
Typical “The Energy Tank” tm Internals
Steam Muffler
Loop Drain
Already Have Continuous Blowdown
Heat Recovery?
Here’s what you are missing from a 1 ½-inch Manual Bottom Blowdown!
BLOWDOWN HEAT RECOVERY – ADDITIONAL SAVINGS OPPORTUNITY
Average Load
Average Load
No Heat Recovery
CBD Heat Recovery
70,000
3,500
1,150
Steam Load, #/Hr
Blowdown Load, #/Hr
Gas Savings, $ / CM
Based on $0.25/CM Gas Cost
>$50,600
>202,000 CM
>$16,000
>64,000 CM
Water Savings, CM
City water eliminated at blowdown tank
>10,000 CM
>$10,000
>4,600 CM
>$4,600
>425 Tons
>134 Tons
Environmental Savings
Tons Carbon Dioxide gas emissions
NET SAVINGS:
GAS:
>64,000 CM
$16,000 ABOVE CURRENT SAVINGS
EMISSIONS: >134 TONS OF CARBON DIOXIDE GAS
WATER:
>4,600 CM CITY WATER
>$4,600
How GREEN are your BLUE Numbers?
BHR Energy Calculation available at
www.blowdownheatrecovery.com
PLANT LOCATION:
Boiler Horsepower:
Projected Load:
Efficiency (Fuel to Steam)
Cycles of Concentration:
Steam Pressure:
Steam Temperature:
Sensible Heat at Steam Pressure:
Make-up Water Temperature:
Projected Make-up Temperature:
Percent Condensate Returns:
Condensate Temperature:
Hours of Operation per Day:
Days Operation per Week:
Cost of Gas:
Food Plant in Toronto
400
85
70
15
100
338
309
60
100
85
160
24
5
$0.3500
BHP
%
%
Cycles
psig
Deg. F
BTU/#
Deg. F
Deg. F
% of Steam Flow
Deg. F
Hours
Days
$/CM
How GREEN are your BLUE Numbers?
BHR Energy Calculation available at
www.blowdownheatrecovery.com
Calculated Steam Load:
Calculated Blowdown Losses:
Total Boiler Feedwater Flow:
Flash Steam Potential:
Flash Steam From Blowdown:
Flash Energy Available:
Energy to Heat Condensate to Steam Temp.:
Energy to Heat Make-up to Steam Temp.:
Projected Energy to Heat Make-up:
Energy to Heat Boiler Feedwater - Existing:
Energy to Heat Boiler Feedwater - Projected:
Energy Saved:
Equivalent Gas Saved:
Daily Savings:
Annual Savings:
11730
782.0
12512
11.4
89.1
102428.1
1774749.0
706537.0
604877.0
2481286.0
2277197.9
6997306.6
195.2
$68.33
$17,766.60
#/Hr
#/Hr
#/Hr
% to 7 psig dea.
#/Hr
BTU/Hr
BTU/Hr
BTU/Hr
BTU/Hr
BTU/Hr
BTU/Hr
BTU/Day
CM/Day
$/Day
$/Year
CASE STUDY
Major Pharmaceutical Company, NJ USA
Installation Detail
Pharmaceutical Plant, NJ – Test Data (August 2009 – 1 Minute Time Stamps)
Blowdown Heat Recovery Process - Temperature Evaluation
One Minute Time Stamp Intervals from Externally Mounted Thermocouples
2 x CB-300HP Boilers / Manual and Conductivity Controlled Blowdown
Temperature (Deg. F)
Flash Steam and Make-up Outlet Temperatures
300
Red Line = Flash Steam Outlet Temperature
Thermocouple on outside of piping. Temperatures above 212F confirm
steam flow to heat pipe above atmospheric steam temperature.
250
200
150
100
50
1
1285 2569 3853 5137 6421 7705 8989 10273 11557 12841 14125 15409 16693 17977 19261 20545 21829 23113 24397 25681 26965 28249 29533 30817
Time in Minutes (August 1st - 31th, 2009)
Temperature (Deg. F)
Flash Steam and Make-up Outlet Temperatures
August 1st
300
Blue Line = Make-up Outlet Temperature
Thermocouple on outside of piping.
Wavy lines represent on/off flow and changing velocity.
250
200
150
100
50
1
42
83
124 165 206 247 288 329 370 411 452 493 534 575 616 657 698 739 780 821 862 903 944 985 1026 1067 1108 1149 1190 1231
Time (Minutes)
“Energy Tank” Project
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Project Cost: $46,500
Savings: $24,000/yr
Funding Source: CPA
Time to Implement: 3
Months From CPA
Approval