Boiler Cycles of Concentration
Calculates the ratio of dissolved solids in boiler water vs. feedwater using conductivity or chloride tracer methods. Compares results against ABMA maximum CoC guidelines by operating pressure.
Conductivity Method:
CoC = EC_boiler / EC_feedwater
Chloride Method:
CoC = Cl⁻_boiler / Cl⁻_feedwater
ABMA Maximum CoC by Pressure:
0–300 psig → max 70
301–450 psig → max 60
451–600 psig → max 50
601–750 psig → max 40
751–900 psig → max 25
901–1000 psig → max 20
1001–1500 psig → max 15
1501–2000 psig → max 10
Blowdown Rate & Heat Loss
Calculates continuous blowdown flow, heat energy discarded, annual fuel cost, and recoverable heat with a flash tank. Enter steam generation rate (or boiler HP) and target CoC.
Blowdown Percentage:
%BD = 1 / (CoC − 1) × 100
Blowdown Flow:
Q_BD (lb/hr) = m_steam × (%BD/100) / (1 − %BD/100)
Enthalpy of Boiler Water (h_bw): From steam tables at operating pressure — interpolated from embedded table (100–1000 psig: 309–543 BTU/lb).
Feedwater Enthalpy:
h_fw (BTU/lb) ≈ T_fw (°F) − 32 [Cp_water ≈ 1 BTU/lb·°F]
Heat Loss:
Q_BD_loss (BTU/hr) = Q_BD × (h_bw − h_fw)
Annual heat loss (MMBTU/yr) = Q_BD_loss / 1,000,000 × 8760
Flash Tank Recovery:
Q_recoverable = Q_BD_loss × 0.35
Steam Purity
Estimates steam TDS and condensate TDS from mechanical carryover, then compares against ASME steam purity limits by pressure. Optionally calculates vaporous silica carryover.
Steam TDS from mechanical carryover:
Steam_TDS (ppm) = TDS_BW × (carryover% / 100)
ASME Steam Purity Limits (TDS in steam):
<300 psig: ≤ 1.0 ppm
300–600 psig: ≤ 0.5 ppm
600–900 psig: ≤ 0.2 ppm
>900 psig: ≤ 0.1 ppm
Condensate TDS is approximately equal to steam TDS (dissolved solids carried into condensate). Vaporous silica carryover is estimated using the ABMA silica partition table (see Calculator 6).
Deaerator O₂ Scavenger Dosing
Calculates required active dose and product feed rate for oxygen scavenger (sodium sulfite, SMBS, or DEHA) based on post-deaerator dissolved oxygen and target residual.
Dose calculation (DO converted from ppb to ppm = ppb / 1000):
Na₂SO₃ dose (ppm) = DO (ppm) × 7.875 + residual (ppm)
SMBS dose (ppm) = DO (ppm) × 6.3 + residual (ppm)
DEHA dose (ppm) = DO (ppm) × 3.0 + residual (ppm)
Feed Rate (GPM flow):
Flow_Lpm = GPM × 3.785
Feed rate (mL/min) = Flow_Lpm × dose_ppm / (C% × SG × 10)
Feed rate (lb/day) = GPM × 1440 × 8.34 × dose_ppm / 1,000,000
Annual (gal/yr) = Feed_GPH × 8760
Condensate Return Contribution
Calculates blended feedwater quality (TDS, hardness, conductivity) from mixed condensate return and makeup water, plus annual water savings from condensate recovery.
Q_cond = Q_fw × (CR% / 100)
Q_mu = Q_fw × (1 − CR% / 100)
TDS_fw = (Q_cond × TDS_cond + Q_mu × TDS_mu) / Q_fw
H_fw = (Q_cond × H_cond + Q_mu × H_mu) / Q_fw
EC_fw (µS/cm) ≈ TDS_fw / 0.55
Annual savings (gal/yr) = Q_cond (GPM) × 60 × 8760
Silica Carryover Risk
Uses ABMA silica partitioning data to determine maximum allowable boiler water SiO₂ for vaporous carryover control and assess turbine scaling risk. Scalable to any target steam SiO₂ limit.
ABMA Silica Partitioning Table (at 0.02 ppm steam target):
300 psig → 150 ppm BW SiO₂ max
400 psig → 90 ppm
500 psig → 50 ppm
600 psig → 28 ppm
700 psig → 15 ppm
800 psig → 9 ppm
900 psig → 5.5 ppm
1000 psig → 3.2 ppm
1200 psig → 1.2 ppm
1500 psig → 0.5 ppm
Scaling for other steam SiO₂ targets:
Max_BW = TableValue × (target_steam_SiO₂ / 0.02)
Estimated steam SiO₂:
Steam_SiO₂ = Current_BW_SiO₂ / TableValue × 0.02
Values at pressures between table points are linearly interpolated.