HeatSponge™
2-Stage Condensing Economiser

An economiser in the field is most often a feedwater economiser, which recovers waste heat from boiler flue gases and uses it to preheat feedwater, reducing fuel use and operating costs. While the technology has been around for decades, many traditional economisers are built from carbon steel and fail prematurely due to corrosion, leaks, and thermal stress. As a result, countless units end up abandoned in boiler rooms, no longer delivering savings.

Even if a plant already has an economiser installed, older designs often develop leaks within a few years, with repairs costly and unreliable. Without a permanent solution, efficiency gains are quickly lost. The HeatSponge 2-Stage solves this problem with stainless-steel construction and removable 316 tubes, ensuring long-term durability and lasting efficiency improvements of up to 12%. Different material options are also available to match corrosion resistance requirements, providing a tailored, long-term solution for each application.

The HeatSponge 2-Stage is particularly well suited for medium to large industrial and institutional steam plants. It provides the greatest value at sites with high makeup water requirements or where conventional economisers have failed. Compact and versatile, it can often replace a failed unit in the same footprint while delivering reliable performance and higher savings.

Thermal Energy can also provide feedwater economisers and single stage condensing indirect economisers as required by customer needs.

Recovered heat from FLU-ACE can be applied to a wide range of uses, including domestic hot water, hydronic and space heating, boiler makeup water preheating, process water heating, combustion air and makeup air preheating, and even low temperature drying lines or biomass drying integration.

Additionally, heat recovered with a FLU-ACE can be increased in temperature for broader application with a heat pump, generating far superior coefficients of performance (COPs) than air or ground source heat pumps. In fact, latent heat can be recovered and upgraded to steam in our “FreeSteaming^TM” combined heat recovery or mechanical vapour recompression applications, closing the latent heat cycle on dryers and other processes.