Boiler Systems

Steam producing boilers are designed to operate with exhaust gas temperatures ranging from 350 to 550 F ( approximately 50 to 100 F above saturation temperature ) at design conditions. Decreasing this temperature with a heat recovery device will result in a corresponding increase in boiler efficiency.

Boiler economizers are heat exchangers installed in the stack to recover heat from the high temperature exhaust gas and transfer it to various heat sinks such as boiler feedwater, cold makeup water, combustion air, process water, glycol, and thermal fluids.

Dependent on the application and utilization of recovered heat, boiler efficiency improvements of 4-7 % can be expected for conventional economizers recovering sensible heat only, to 15% for condensing economizers which also recover latent heat.

Waste Heat Boilers which operate on higher temperature exhaust gases from reciprocating engines, turbines and thermal oxidizers utilize the recovered energy for steam production.


  • Vertical or horizontql gqs flow for larger boilers varying from 10,000 to 250,000 PPH steam production


  • Space saving "in the stack design" for smaller boilers ranging from 50 HP – 45000 PPH These compact economizers lower flue gas temperature by preheating boiler feedwater.


  • Unfired boilers producing steam utilizing hot exhaust gases from turbines, engines, thermal oxidizers, kilns, and dryers.
    • Water tube designs up to 150,000 PPH and 700 psi
    • Fire tube designs up to 1000 PPH and 300 psig


  • Maximum heat recovery is achieved by lowering stack temperatures below the dew point of water vapor in the flue gas. In addition to increased sensible heat recovery, a latent heat component is also recovered resulting in significantly greater efficiencies than conventional economizers.


  • Gas to gas heat exchangers which transfer heat from hot flue gas to preheat incoming combustion air.