The design has been installed in a food processing plant in Missouri, USA. In total, five BEI economizers were installed at the plant; two were conventional boiler feedwater models, however for the other three, the client’s significant cold water heat sink provided an ideal opportunity for full condensing heat recovery in a conventional economizer installation above the boiler - utilizing BEI’s trailblazing Type III configuration.
HeatSponge Type III Configuration
Around 10% of the energy inputted to a boiler is lost through latent energy losses. Water formed in the combustion process is turned into vapour which cannot be recovered inside a steam boiler passing into the atmosphere. Economizers that utilize cold-water heat sinks enable recovery of this latent energy available in condensing, unavailable when in typical hotter boiler feedwater sinks. Condensing economizers can result in up to four times the higher rates of heat recovery than non-condensing designs.
Most indirect contact economizers on packaged boilers are located above the boiler with the exhaust gases entering the bottom and travelling vertically upwards. This orientation poses significant problems on heavy condensing installations for two key reasons:
BEI’s type III configuration incorporates an internal three-pass exhaust gas path that allows the gas to enter vertically up from the bottom, yet transition to gas flow down over the heat exchanger and exit from the top in a conventional orientation.
An isolated sump ensures no condensate can ever enter the boiler and using the draft available in the combustion air fan, we do not need an external fan to overcome the draft loss across the economizer.
“At a time of escalating energy prices, this technology stands to reshape the global approach to heat recovery,” said BEI president Vince Sands.