Pre-Engineered Economizer Solutions

Required Data*

(This data is required to make a preliminary selection.)

 HPPPHBTUHEnter Boiler Capacity: Required Data
You may enter your boiler capacity in Boiler Horse Power (HP), Boiler Pounds per Hour (PPH) capacity, or BTU input per hour (BTUH). Firetube boilers are typically rated in HP while watertube boilers are rated in PPH. Smaller commercial boilers rated in BTU input require the input to be entered in million BTU per hour, for example a 1,500,000 btu/hr unit should be entered as 1.5 in the data entry area.

 Economizer Inlet Water Temperature F: Required Data
Water inlet temperatures under 215 F will be considered non-deaerated – stainless steel tube required and will be included. Note if the economizer is to be used for a process water (non boiler feedwater) application you will have the opportunity below to enter a custom water flow rate.

 Economizer Flue Gas Inlet Temperature F At High Fire: Required Data
If you’re not sure:
Firetube: If unknown assume 75 degrees above saturated steam temperature
Watertube: If unknown assume 150 degrees above saturated steam temperature
Click here for steam tables to see saturated steam temperatures
Optional Part-Load Gas Temperature Inputs Available Below in Optional Input Section.

Boiler Type the Economizer Will Be Installed On: Required Data
Any boiler with an atmospheric burner
Firetube Boiler (Scotch Marine)
Flex-tube Watertube Boiler
Industrial Watertube Boiler
This is very important as firetube boilers typically require a lower draft loss across the tube bundle than an industrial watertube boiler. The AutoPick program needs to know what type of stack draft loss to select the unit for. All Pre-Designed Economizer economizers are designed for boilers withe forced draft blowers only. If you are an experienced boiler technician and understand the unique draft requirements of your boiler you may select an alternative maximum draft loss with the AutoPick OFF selection below.

Unit Recovery Type – BASE, SUPER, MICRO, TOP: Required Data
MICRO – Economy Coiled Unit – Typically under 275 HP Only
BASE – Base Unit – Lowest Capital Cost Standard Pre-Designed Economizer
SUPER – High Recovery Unit – Higher Capital Cost Standard Pre-Designed Economizer
TOP – Very Large Boiler Pre-Designed Economizer

This provides the user an opportunity to select a unit configuration based on desired recovery and capital expense. The AutoPick software is designed to automatically switch to a SUPER unit from a BASE unit if the energy recovery is higher and there is no difference in price from the BASE model. We recommend looking at both a BASE and a SUPER unit and comparing the additional recovery and unit cost to make the most economical purchase decision.

If your application is too large for a conventional BASE or SUPER unit the AutoPick software will automatically switch to a TOP configuration. The TOP is the largest Pre-Designed Economizer available and is designed primarily for larger industrial watertube boiler applications. A TOP cannot be manually selcted.

The MICRO economy coiled economizer reflects a lowest dollar unit for applications typically to 275 HP. If the MICRO unit is selected for a boiler too large the software will automatically switch to a BASE unit and activate the AutoPick software. Since the coiled units do not feature replaceable tubes as the standard Pre-Designed Economizer units as surfaces exposed to flue gas including the tubes, fins, baffles, and casing are manufactured out of stainless steel as a standard to provide a maximum unit longevity. This is a very high quality unit for smaller installations.

If you require even high heat recovery you may select the Stack Economizers option in the Optial Input selection below.

End of required data requirements for typical Pre-Designed Economizer Applications. This is a minimum requirement, final unit selection could be affected by other operational constraints. Additional data inputs are located below. Pre-Designed Economizer reviews all selections for accuracy prior to placement of any purchase order.

Project Specific Input: Entered on a project-by-project basis.

Boiler Manufacturer Economizer Will Be Installed On: Project Specific Input
Select Manufacturer— Atmospheric Commercial Boilers —To be Advised— Firetubes (Scotch Marine) —BurnhamColumbiaContinentalCleaver-BrooksCleaver-Brooks LECyclothermDonleeEclipseEnglish BoilerHurstIndustrialJohnstonKewaneeMyrggoNorth AmericanSellersSuperiorTriad Boiler SystemsYork-ShipleyUnlisted Firetube— Flextube Watertubes —BryanEnglish BTBFUnilux FlextubeUniversal Boiler WorksUnlisted Flextube— Industrial Watertubes (D-A-O-S Types) —ABCOAalborgB & WBigeloCleaver-Brooks D-TypeClaytonCombustion EngineeringEnglish BoilerErie CityFoster WheelerFultonIndeck-KeystoneKeelerMurry TraneNebraskaRentechUniluxUnion Iron WorksVapowerVictory EnergyVolcanoZurnUnlisted Industrial Watertube
We recommend you enter the manufacturer of the boiler if known as some boilers, primarily firetube boilers, have a lower tolerance for flue gas backpressure. Not selecting any specific manufacturer will result in the use of default data for the boiler type selected.

Existing Boiler Efficiency:
You can change the efficiency of the exisiting boiler system. The default is 81%. The fuel mass flow rate calculations are based on this number so should not only be changed with care and knowledge.
Select Current Boiler Efficiency: 0.810.790.780.750.720.700.650.800.820.830.84

Part-Load Flue Gas Temperature Input: Project Specific Input
The AutoPick software will automatically reduce flue gas temperature for typical applications. If you wish to enter specific flue gas temperatures at part-load firing rates you may do so below. NOTE ! If you do not want to enter other gas temperatures then leave these cells blank !
Gas Temperature at 100% Load: Entered Above in REQUIRED section
Gas Temperature at 75% Load:  deg F
Gas Temperature at 50% Load:  deg F
Gas Temperature at 25% Load:  deg F

 Burner Flue Gas Recirculation Rate: Project Specific Input
Enter the FGR rate only if your burner utilizes FGR and only if the FGR connection to the burner is downstream of the economizer. If your burner does not use any FGR then leave this cell blank. Typical Low NOx burners run 5% to 15%. Standard burners have no FGR so leave cell blank.

Enter Blowdown Rate (%): 0123456789101112131415 Project Specific Input
This is the percent continuous (surface) blowdown. Enter if known.

Enter Fuel Price ($/mbtu): 8.008.258.508.759.009.259.509.7510.0010.2510.5010.7511.0011.2511.5011.7512.0012.2512.5012.7513.0013.2513.5013.7514.0014.2514.5014.7515.0015.2515.5015.7516.0016.2516.5016.7516.0016.2516.5016.7517.0017.2517.5017.7518.0018.2518.5018.7519.0019.2519.5019.7520.0020.2520.5020.7521.0021.2521.5021.7522.0022.2522.5022.754.004.254.504.755.005.255.505.756.006.256.506.757.007.257.507.75 Project Specific Input
Select the price of natural gas in dollars per million btu’s.

Enter Annual hours of Operation: Project Specific Input
There are a total of 8,760 hours in one year
875015001000150020002500300035004000450050005500600065007000750080008500 At 100% Firing
15001000150020002500300035004000450050005500600065007000750080008500 At 75% Firing
15001000150020002500300035004000450050005500600065007000750080008500 At 50% Firing
15001000150020002500300035004000450050005500600065007000750080008500 At 25% Firing
These hours will be reflected in each of the four load performance runs

Unit Fin Count: Project Specific Input
5 Fins per Inch – Gas Firing Only
4 Fins per Inch – Gas and Consistant #2 Oil Firing
3 Fins per Inch – Fuel Oil Firing
You may select 5 fins per inch if your plant fires gas with a #2 oil for standby use of less than one week annually. 4 fins for constand #2 oil firing, and 3 fins for heavy oil, #6, or other dirty fuels. If unsure leave at 5 fins.

Optional Input Section

 PPHGPM% Make-Up Custom Water Flow Rate (lbs/hr): Optional Input
Enter the water flow rate ONLY if the flow rate will differ from the boiler capacity flow rate. This feature is for economizers used in a non-traditional installation such as process water heating. If your application is a typical boiler economizer arrangment then leave this cell blank and leave units on PPH!

• PPH – Enter an exact value in pounds per hour (PPH) non-deaerated water flow through the economizer
• GPM – Enter an exact value in gallons per minute (GPM) non-deaerated water flow through the economizer
• % of Make-Up – enter as a percentage number between 25 and 100 when using cold non-deaerated water prior to delivery to feedwater tank. Not valid for dearated water flow to boiler.

Stacked Economizers: Optional Input
Stack Units
Do Not Stack Units
Stacking economizers is a way of increasing heat recovery by placing two identical units on top of each other. The price will be double the price of the individual units. Stacking is to be utilized when very high heat recovery is required. Stacked units will also be much wider than a single unit as each unit will only be able to accomodate half of the allowable gas side pressure drop as a single unit would be allowed.

Target Flue Gas Outlet Temperature: Optional Input
 Enter Target Gas Exit Temperature deg F
Stay with Model Selected
Increase Model Size
If you need a unit to meet a specific flue gas exit temperature enter the value in the above data field and the AutoPick Algorthym will manipulate various designs to come as close as possible. The radio buttons allow the AutoPick Algorthym to decide whether to stay with the model selected or increase model size in the event achieving the target gas temperature is not possible with the given model size selected. Selecting Increase Unit Size may not select the most cost effective unit so we recommend you do not change the radio button unless you consider changing model types as well to obtain the optimum unit selection.

Tube Material Override: Optional Input
Override ON
Override OFF
By default units with deaerated water will be supplied with carbon steel tubes, all other applications and all MICRO units have stainless steel tubes. Should you wish to override the carbon steel tube selection for deaerated applications and utilize a stainless steel tube click the button above. We do not permit the use of carbon steel tubes in any non-deaerated process.