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SCAPH flash-steam air preheat for a tyre plant
At a tyre industry plant, Grandeh steam coil air preheaters (SCAPH) recover spent flash steam and use that heat to warm combustion air before it enters the boiler.
Flash steam that would otherwise leave the process is the heating medium inside the finned coils. Air from the fan crosses the fins, picks up that heat, and reaches the furnace already warm. The boiler then needs less coal to raise the same steam.
What the plant gains
- Spent flash steam is put back to work instead of being vented
- Combustion air is preheated on the way to the boiler
- Lower coal firing for the same steam duty
- A practical energy-saving step for a tyre-plant boiler house
The coil, headers and casing were fabricated at Grandeh works in Aurangabad, with IBR-aligned pressure-part practice. Project partners can follow inspection records on the Grandeh project portal.
Where the coal saving comes from
Flash steam that has already done one job still holds latent heat. In this SCAPH it enters the inlet header, condenses in the finned tubes and gives that heat to combustion air crossing the fins. The air reaches the coal-fired boiler warm, so the furnace fires less coal for the same steam. Condensate leaves through the return header. Traps and vents keep the coil from filling with water or air.
Nothing in that path requires a new fuel. The heating medium is steam the plant was already producing and not fully using. The same coil type is used on distillery boilers for a different reason — fouling flue gas — described on the distillery page. The tyre-plant version of the duty is collected on the tyre plant page.
Figures that size the next one
- Flash-steam pressure, temperature and the flow that is actually spare
- Combustion-air flow and the temperature rise required
- Duct size and the pressure drop the fan can spare
- Boiler steam conditions, so the coil matches the coal-fired unit it serves
