Utilities
Blowdown is smaller than its reputation and flash is larger. Both are worth knowing before either is chased.
— cost/t
Fuel only, after efficiency and blowdown
This is a steady-state balance on the boiler and says nothing about the distribution system, where most of the losses a textile mill actually has are found: uninsulated line, failed traps passing live steam, and a plant carrying far more header pressure than any user needs. A mill with an excellent boiler figure and poor traps is burning fuel this calculation cannot see. Blowdown here is continuous surface blowdown at a declared rate; intermittent bottom blowdown is additional and is set by sludge rather than by conductivity, and neither should be reduced on the strength of a heat figure alone - blowdown exists to control dissolved solids, and cutting it to save the fraction of a percent shown here buys carryover, foaming and eventually tube damage. The honest way to reduce it is better feedwater. Flash steam is reported as recoverable rather than recovered: capturing it needs a flash vessel and a genuine use at the lower pressure, and a plant with no low-pressure demand cannot use it however much of it there is. Fuel cost per tonne of steam is the number worth carrying into every other calculation on the site, since it converts a thermal saving anywhere into money.
Boiler Heat Balance, Blowdown Loss & Flash Recovery — free, with the formula and a worked example, at Textile School.