The Vertical Mill

The vertical mill is a kind of mill equipment, widelyis a large ventilation cross-section in the mill and
used in cement chemicals, coal, electricity andthe air resistance is very small. The materials with
other fields. With the advantages of small8% moisture can be dried by the exhaust gas
footprint, low power consumption, small noise,from preheater in the end of kiln. If there is a hot
simple process, layout compact, combined withair furnace, the materials with 15%-20% water
crushing, drying, grinding, classifying as a whole,content will be dried.
the vertical mill has become the preferred3, The feeding size can be very large, usually can
equipment for milling cement raw meal in thebe up to the length as 5% of the roller diameter.
modern cement production factories.The large vertical mill’s feeding size can be up
The world's first vertical mill was developed byto 150 ~ 200 mm. The equipment has superior
Loesche Company from Germany, who had thetechnical performance and is of high capacity. It
mature design already in the year of 1925. Athas high rate of operation and lower metal-worn
present, the largest vertical mill - LM63?4, has athan the ball mill.
capacity of 840 TPH, with the millstone diameter4, Strong adaptability to grinded materials. The
of 6.3mm, the power of 5600 KW and is equipedvertical mill can be used to grind a variety of
with 4 rollers.materials, such as limestones, sandstones
The current abroad manufacturers of vertical mills(Si02> 90%), coals, cement clinkers, blast
mainly include Loesehe Company, Fuller Company,furnace slags and so on. No matter the
UBE Company (LM series of vertical mill), FLSdifferences of raw material’s easy-grinding or
Company (Atox Mill), KHD Company (RM mill) andabrasive, the vertical mill can produce qualified
Pfeiffer Company (MPS series of vertical mill). Theproducts with different fineness and different
domestic manufacturers of vertical mills have aspecific surfaces just by adjusting the internal
relatively small amount, whose R&D andstructure and operating properly.
production are still in the developing level.5, with simple process and compact layout, lower
However, compared with international brands, theroutine maintenace cost. It can be used as
domestic brands have some uniqueopen-air setting and can save 70% construction
characteristics, which are better suited to theinvestment than the ball mill.
domestic market.6, Good overall airtight performance, small dust,
Compared with other grinding equipment, thelow noise and superior environment.
vertical mill has the following features.7, Convenient and fast control for finished
1, With high efficiency of grinding. Using theproducts, flexible product adjustment and easy to
principle of material bed’s crushing andachieve operational intelligence and automation.
squeezing, the material is rolled, cutted, impacted8, The disadvantages of the vertial mill include
in the mills; the airflow in the mill can take thethat it is not suitable for grinding hard and
grinded materials out timely to avoid excessivelyabrasive materials. And its easy-wore parts are
grinded; the materials generally stay in the mill formore expensive than ball mills’. However,
2-4 minutes. The vertical mill has the 165%compared with the total amount of maintenance
grinding efficiency as the ball mill and the powerfor the ball mill, elevator, and separator which the
consumption can be reduced by 30% or so.vertial mill replaces, the vertial mill still has simpler
2, With high drying efficiency. Hot air spray inmaintenance, easier operation and smaller amount
from the annular gap with high wind speed; thereof work.