Two bespoke boiler economisers installed at a chemical production facility

ThermTech were asked to design, manufacture and retrofit two bespoke steam boiler economisers to the boilers for a UK based specialty chemicals production facility to help further improve the energy efficiency of the site.   

The two natural gas fired boilers located at the site’s boiler house are each designed to provide a maximum of 15,000 kg/hr of steam at 22 bar g maximum pressure to the site’s steam main.

The two boiler exhausts are located very close to the boiler house wall, making retrofitting economisers at the optimum size inside the boiler house difficult due to available space restraints.

Steam Boiler Economiser Solution

The solution was to install the economisers outside, alongside one side of the boiler house wall.  The boiler economisers were designed with gas side transitions to suit the existing flue ductwork and steel channel support frames to ground level, allowing for a simple installation programme.  The boiler economisers are each designed to cool the boiler flue gases from 245 °C to 138 °C, thereby preheating boiler feed water from 87 to 120°C.

This translates to a boiler efficiency uplift of approx. 6%.  The consequent savings in natural gas mean the project will likely pay for itself in less than a year from the date of commission and reduce carbon emissions by approximately 450 tonnes of CO2 / year.