What Is the Flue Gas Sulfuric Acid Dew Point & Cold-End Corrosion Calculator (Verhoff-Banchero)?
Combustion of sulfur-bearing fossil fuels (heavy fuel oil, coal, petcoke) oxidizes sulfur to SO2, of which 1% to 5% further converts to sulfur trioxide (SO3).
SO3 reacts instantly with water vapor to form sulfuric acid vapor (H2SO4), raising the condensation dew point from ~50°C (pure water) to 120-160°C.
Operating air preheater or economizer tube metal below the acid dew point causes rapid cold-end metal wastage and fouling. This calculator uses the Verhoff-Banchero correlation to predict T_adp and determine safe flue gas temperatures.
How Does the Flue Gas Sulfuric Acid Dew Point & Cold-End Corrosion Calculator (Verhoff-Banchero) Work?
The calculation evaluates user-provided measurements using recognized domain equations, converts between measurement units, and adjusts for real-world efficiency factors.
Flue Gas Sulfuric Acid Dew Point & Cold-End Corrosion Calculator (Verhoff-Banchero) Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Verhoff-Banchero thermodynamic vapor-liquid equilibrium correlation for H2SO4-H2O systems.
How to Use the Flue Gas Sulfuric Acid Dew Point & Cold-End Corrosion Calculator (Verhoff-Banchero)
- Enter your primary measurements in the input fields above.
- Select your preferred units (e.g. metric or imperial) if applicable.
- Review or adjust operational assumptions such as field efficiency.
- Click Calculate to instantly generate the full results breakdown and visual chart.
- Use the Reset button at any time to clear the form and test a new scenario.
Step-by-Step Example Calculation
Coal-Fired Boiler Flue Gas (15 ppm SO3, 8% H2O, 1.013 bar)
Input Values:
Understanding Your Result
Your calculated result represents the realistic operational capacity or baseline output under the specified conditions. Comparing theoretical and effective outputs reveals the direct impact of turns, overlap, and practical downtime.
Factors That Affect the Result
Field terrain, operator experience, equipment maintenance, overlap margin, and weather conditions can significantly influence real-world output.
When Should You Use This Calculator?
Use this calculator whenever you need quick, verified estimates for job planning, budgeting, equipment sizing, or project timelines.
Assumptions & Limitations
- Verhoff-Banchero Equation: 1 / T_adp(K) = 0.002276 - 0.00002943 · ln(P_H2O) - 0.0000858 · ln(P_SO3) + 0.0000062 · [ln(P_H2O) · ln(P_SO3)].
- Partial pressures P_H2O and P_SO3 are evaluated in mmHg atmospheres.
- Cold-End Metal Margin: Recommended minimum tube metal temperature = T_adp + 15°C.
Frequently Asked Questions
Calculation Accuracy & Reference Note
This calculator implements verified, deterministic mathematical equations based on published standards. Results should be treated as professional engineering estimates; always verify critical operations with local equipment manuals and site inspections.