Nice — let’s do this step-by-step so you get a practical answer you can use on the shop floor.
These numbers are examples — I’ll show how they were calculated so you can plug in your real values.
What I assumed (so you can change them if needed)
1. Steam
properties — saturated steam enthalpy of vaporisation ≈ 2,046.5 kJ/kg (value
used for steam at around ~7 bar gauge). Engineering ToolBox
2. Boiler
fuel-to-steam (fuel) efficiency = 85% (typical modern industrial gas boiler
range ~80–88%). powerhouse.com
3. Gas cost —
I used India benchmark gas price INR 1,057 per MMBtu (Gas Index of India, April
2025). Replace this with your actual fuel price for exact cost. Energetica
India
Notes, caveats & how to get a precise number for
your plant
• What “1 kg
linen” means — actual steam needed depends on fabric, initial moisture content,
and the operation (ironing only vs drying vs steam chest pressing). Typical
ironing/pressing uses much less steam than dryer/evaporative processes.
• Steam
pressure matters — at higher pressures latent heat per kg changes slightly (use
steam tables for precise h_fg at your operating pressure). thermopedia.com
• Boiler
efficiency can vary (scale, blowdown, stacking losses). Use your boiler’s
actual fuel-to-steam efficiency for best accuracy. powerhouse.com
• Fuel type
matters — I used the India natural-gas benchmark. If you use LPG or PNG or
furnace oil, replace the fuel price and calorific conversions accordingly. (I
can convert if you give me your fuel type and price.) World Nuclear Association
Practical ways to measure real steam use:
• Fit a
steam meter (vortex/differential) on the branch feeding the press/finishing
line.
• Measure
condensate return mass/temperature and calculate steam input from mass and
enthalpy balance.
• Use your
boiler gas meter energy reading and proportionate loading/time to apportion
fuel to specific processes.
I would
like to emphasize that this note is shared purely for knowledge-sharing and
educational purposes.
