JFE Engineering has developed a new combustion
control system that is capable of achieving the stable
combustion for various multi-waste-fuels in the circulating fluidized bed boiler (CFB). This system has
advanced control functions with a rule-based type multipurpose control. This device is applied to furnace temperature control, exhaust gas stabilization control, and
blowing control of slaked lime for the reduction of HCl.
The application test was conducted in two CFB plants
and the effect was confirmed that the furnace temperature and exhaust gas condition could be stabilized, and
the fun driven power could be reduced by the reduction
of combustion air.
1. Introduction
Recent years have seen heightened demand for high
efficiency boilers, which use waste-derived fuels such
as wood biomass, plastics, refuse paper and plastic fuel
(RPF), waste tires, sludge, and other recycled materials in place of fossil fuels. The circulating fluidized bed
boiler (CFB) is a boiler, which is applicable to these
diverse waste-derived fuels. The circulating fluidized
bed boilers are already used in a wide range of industries, including paper manufacturing companies, as a
substitute for oil boiler.
JFE Engineering has an extensive supply record of
CFB boilers to date, including coal single fuel combustion, plastics single fuel combustion, and wood biomass
single fuel combustion systems. The company also
delivered two multi fuel combustive CFB boilers to
paper manufacturing companies in 2008 (Photo 1).
In combustion of waste-derived fuels, fluctuations in
the combusting point, local high temperature, instability of the properties of the combustion gas, and simila