Speyside Distillery Boiler Economiser Replacement

The economiser on a 13 ton per hour gas fired steam boiler at a Speyside distillery failed beyond repair. Economisers recover waste heat from the boiler flue gas and use it to preheat the boiler feedwater, so when one fails the fuel cost impact is immediate and significant. The distillery needed an urgent replacement.

T&S used its own proprietary design software to work out the optimal economiser geometry. Because ordering an economiser isn't a routine purchase, the design team also guided the distillery's engineers on what plant data was needed (flue gas flow rate and temperature, boiler pressure, feedwater temperature and flow rate, and physical size limits) and how to source it from the boiler plant.

T&S designed and built a replacement economiser using 123 carbon steel tubes across 7 staggered rows with spiral fins, delivering 610kW of heat recovery. This raised the boiler feedwater temperature from 80°C to 135°C, using flue gas that was exiting at 277°C. At the distillery's gas price, this was forecast to save around £76,128 a year, based on two shifts a day, five days a week.