Bateman Simatek Bagfilter cleans boiler-exhaust
gas at Mondi
Bateman Engineering is currently commissioning four Bateman Simatek
Bagfilters which have been installed to clean gas emissions from a
new Babcock Multi-Fuel boiler at the Merebank site of Mondi Business
Papers S.A. in Durban, RSA. The contract was awarded by the project’s
main contractor, Babcock Engineering.
The Bateman Simatek Bagfilters handle a volume of 245,000 Am3/h
of exhaust gas from the boiler, at a temperature of 160 ºC, and
remove 10 t/h of waste ash entrained in the gas, ensuring that less
than
20 mg/Nm3 of ash is contained in the gas emitted from the
exhaust stack. This emission level is significantly lower than the
industrial standard emission limit of 80 mg/Nm3.
The Bateman Simatek system installed at Mondi comprises four cylindrical
modules, each housing 280 filter bags 8.5 m long with a total filtration
area of 4,174 m2. The waste ash collected on the individual
filter bags is removed efficiently by the application of low-pressure
reverse-flow pulses of air into each filter bag which reduces flex
abrasion and prolongs the filter bag life. Isolation dampers are fitted
to allow one module at a time to be isolated for on-line maintenance.
In the design of Mondi’s Bateman Simatek unit, account has been
taken of the future installation of a gas conditioning and treatment
plant that will enable the Bateman Simatek unit to also remove sulphur
dioxide from the boiler emissions. Conditioning involves the injection
of water and lime into the boiler exhaust duct prior to it entering
the Bateman Simatek unit, so that the lime is trapped on the surfaces
of the filter bags as a reactive bed that absorbs sulphur dioxide
passing through in the gas stream. The lime is converted to non-commercial
gypsum which is removed when the filter bags are cleaned.
To facilitate sulphur dioxide removal by the lime, the design allows
for the filtration area to be increased by about 17 %, the retention
time of the lime layer on the bags to be increased and the differential
pressure across the filter bags to be controlled appropriately.
Babcock selected the Bateman Simatek technology for this application
because it has been proven in over 120 flue-gas applications in Europe
over the past 10 years in which its ability to meet the European air
pollution control requirements has been well demonstrated.
Further information on the application of Bateman Simatek technology
to control the release of environmental pollutants, such as airborne
dust and gases such as HCL,SO2, SOx, and HF in boiler-exhaust emissions
is available from Bob Orr on +27-11-201-2300 or email Environmental@Bateman-bet.com.
