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The fourth generation of static and dynamic
combined type rotary classifier, which was manufactured by
BPEG under the cooperation with German BABCOCK in 1994 and
was first used for GAO BEIDIAN Power Plant. Then, BPEG cooperated
with aerodynamic Experiment Station in Huazhong University
of Science and Technology, got variety performance curve and
developed a series of combined type rotary classifier. Now
455 sets are already put into operation and exported to various
countries.
The rotary classifier made by BPEG is widely
used for electric power generation, chemical, cement and metallurgy
industries. 455 sets are already put in to the market. And
many are exported to Albania, Turkey, Vietnam, Georgia, South
Korea, Syria, Pakistan, India and other countries.
The adjustable range of this classifier is wide
and the performance curve appears to be linearization. The
fineness can reach R90=3% and R95=3.5%.
The rotary classifier can meet the requirements
of fineness for coal powder when burning the low-Nox, which
is good to environment. When the evenness index of coal powder
is increased to 1.3—1.4, without changing the fineness of
coal powder R90, the R200 falls down. It can lower the carbon
content of fly ash, and consequently reduce coal consumption.
Comparing to static classifier, the rotary classifier can
efficiently decrease the wind resistance and vibration of
coal mill.
This is the picture of our rotary classifier
running in Guohua Sanhe Power plant. The lifetime of blades
is more than 50000 hours, better than the imported ones. The
rotary classifier, which is used for Gao Beidian power plant
in 1998, is still running well, there is no damage sign for
both the static and dynamic blades and the inside structure.
The static and dynamic blades are made by wearable steel plates.
BPEG have been awarded the national patent of
sealing system for rotary classifier. The reliable seal structure
are used for oil seal, hermetic seal and powder seal.
The rotor of rotary classifier is driven by
the gearbox to ensure the stability and accuracy of the impeller
rotation. It can also avoid pulley skidding, losing speed
and instable speed phenomena. The pipeline for mill outlet
is equipped with inner lining made by wear resistant ceramic.
High-class dynamic balance is done for the rotor to ensure
its stable running.
The classifying efficiency of combined rotary
classifier is much high. By adjusting the rotation speed of
rotor, the required coal fineness can be obtained. When the
centrifugal acceleration produced by the rotor is above 16g,
the coal fineness can reach R90<=10%, When the centrifugal
acceleration is above 23g, the coal fineness can reach R90=5%.It
can separate the coarse coal effectively and make the evenness
index of coal powder N〉1.3. And very little fines are left
in the unqualified powder, so to avoid the duplication of
the coal grinding and excessive crushing.
BPEG has over ten years history for rotary classifier,
which is widely used for different fields. For the power industry
in China, there are many power plants including 1000MW project
apply the rotary classifier.
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