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TheBlueprintof Water
Blueprint Pro · System component · type: boilerWorked example · inputs locked

Where the water and the heat actually go, and what condensate return does to all of it.

Operating Case

Results update automatically.

Average steaming rate for the period you are modeling.
lb/hr
Drum pressure. Sets steam properties and carbonate breakdown.
psig
The star input. Drag it and makeup, fuel, blowdown heat, and amine demand move at once.
%
Makeup at this return8.4 gpm 4,211 lb/hr of 10,526 feedwater
At the receiver or DA inlet.
°F

At the receiver.

City water.
°F

City water.

Leaving the DA or feedwater tank.
°F

Leaving the DA.

Boiler cycles, feedwater basis. The free boiler room's alkalinity ceiling says how high they can go.
×

Feedwater basis. Max cycles in the free room.

Natural gas per therm; #2 oil per gallon at 138,500 Btu; propane per gallon at 91,500 Btu.
Price per purchased fuel unit.
$/thm

Per therm.

Typical 80 to 83% for a gas firetube; enter it from your stack analysis if you have it.
%

From the stack analysis.

Operating hours a year.
h/yr

Hours a year.

Makeup total alkalinity, post treatment. Softening does not remove alkalinity; a dealkalizer or RO does. Drives the CO₂ and amine chain.
ppm

ppm as CaCO₃, post treatment.

Neutralize to pH 8.3, one mole of amine per mole of CO₂ for the monoamines. Demand is gross; with a DA, 50 to 100 percent of the amine in returned condensate recycles.
Sets feedwater dissolved oxygen for the scavenger demand. A failing DA shows up in the scavenger card first: 200 ppb instead of 7 is about 30 times the demand.
Optional. Overrides the deaerator preset, in ppb.
ppb

Optional override. Blank uses the DA.

Pounds of product per pound of oxygen, stoichiometric.
Scavenger feed above stoichiometric.
×

Above stoichiometric.

Boiler water residual held via blowdown, ppm.
ppm

Held via blowdown.

Click on any stream to learn more.

Where the Water and the Heat Go

Water in lb/hr over energy in MMBtu/h. Drag the return slider and four outputs move at once.

drag the slider, four outputs move at once
Operating Conditions
Steam
10,000 lb/hr
Pressure
100 psig
Condensate Return
60%
Cycles
20 ×
Feedwater
220 °F
Fuel
Natural gas, $1.10/thm

Key Results

The water, the fuel, the blowdown heat, and the chemistry the return sets.

Returned condensate brings back 0.76 MMBtu/h, $81,335/yr against no return.

Makeup Water Feedwater less the returned condensate. What the softener has to treat.

8.4 gpm

4,211 lb/hr, 4.04 Mgal a year

Size the makeup softener from this rate.

Fuel Boiler fuel for the year plus the feedwater heating the DA draws, so the figure moves with the return slider.

$1,182,205 /yr

12.30 MMBtu/h, 984,359 therm/yr

Boiler duty 10.09 MMBtu/h at 82%; $99,409/yr of it warms the feedwater.

Blowdown Heat Heat leaving in hot blowdown against a cold makeup reference, priced at the combustion efficiency.

$15,872 /yr

0.15 MMBtu/h, 1.2% of fuel

526 lb/hr leaving at 337.9 °F. Heat recovery starts here.

Condensate pH Untreated condensate pH on a 25 °C sample basis, from the CO₂ the steam carries.

4.70 untreated

38.5 ppm CO₂, 9.2 lb/day

Feedwater alkalinity 48 ppm, f(P) 0.822 at 100 psig.

Amine Demand Gross demand as 100 percent active. Real demand runs lower with a deaerator.

20.8 lb/day

cyclohexylamine, gross, as 100% active

With a DA, 50 to 100 percent of the amine in returned condensate recycles (Clayton, Table III). Real demand runs lower.

Oxygen Scavenger Demand from the feedwater oxygen at the chosen excess, plus the product leaving with blowdown to hold the residual.

0.40 lb/day

0.02 demand at 7 ppb + 0.38 residual

At a few ppb the residual dominates the demand, itself a teaching output.