Leading Building Materials Manufacturer

The project integrated HeatSponge two-stage economisers with the site’s existing boiler systems to recover thermal energy from flue gases and return it to the process as useful heat. The upgrade delivers higher energy efficiency, long-term reliability, and lower emissions, marking a key step in the company’s broader decarbonisation pathway.

The objective was to achieve measurable reductions in natural gas consumption and greenhouse gas emissions while maintaining continuous production and minimising operational risk.

Each existing boiler was equipped with a HeatSponge two-stage economiser engineered to maximise waste heat recovery from the flue gas stream. 

Stage One: Boiler feedwater enters at approximately 108 °C and is preheated by flue gas at 204 °C, recovering a significant portion of sensible heat.

Stage Two: Cold makeup or process water entering at 21 °C is heated by flue gas at around 161 °C, condensing moisture in the exhaust and reclaiming latent heat that would otherwise be lost.

Combined, the two stages recover up to 0.712 MW at full load, representing approximately 8% of the total boiler heat input and delivering an overall efficiency improvement of around 10%.

The system is constructed entirely from stainless steel, with removable 316 stainless steel tubes and a fully insulated, serviceable design to ensure reliable long-term performance under demanding industrial conditions. 

All boilers were upgraded simultaneously during a planned shutdown, allowing seamless coordination with other on-site contractors. All three units were successfully completed within a single week, demonstrating exceptional planning.