The 82,500 pound-per-hour Cleaver-Brooks Nebraska D boiler system is designed to respond to changes and adapts well to variations in the cyclical loads of the paper machines, Cleaver-Brooks says. The new CBND responds immediately to non-predictive issues such as sheet breaking and, as a result, saves the plant additional money.
The boiler at the 700-ton-per-day paper mill has met or exceeded all of its emissions requirements and is well below the CO requirement of less than 50.
In 2012, the EPA released its final Clean Air Act standards for industrial boilers and incinerators. The standards cover only the highest emitting boilers and incinerators, typically operating at refineries, chemical plants and other industrial facilities.
The 99 percent of the approximately 1.5 million boilers in the US either are not covered by the rules because they burn clean natural gas at area source facilities and emit little pollution, or can meet the new standards by conducting periodic maintenance or regular tune-ups, according to the EPA.
Making modifications to boiler burners to allow the use of natural gas often makes sense in the long term in terms of costs and emissions savings, according to an April report by Pollution Engineering.
Many commercial boiler operators have made such a switch, but such changes affect temperatures, velocities and heat absorption in the equipment. The first step when weighing a conversion to natural gas needs to be a comprehensive assessment of the impact that any changes will have on boiler performance — both gas- and steam-side — and emissions.