Performance Characteristics of Vertical Mill

The vertical mill is a kind of mill equipment which is widely used in cement chemicals, coal, electricity and other fields. With the advantages of small footprint, low power consumption, small noise, simple process, layout compact, combined with crushing, drying, grinding, classifying as a whole, it has become the preferred equipment for milling cement raw meal in the modern cement production factories.

The world's first vertical mill was developed by Loesche Company from Germany, who had the mature design already in the year of 1925. At present, the largest one - LM63．4, has a capacity of 840 TPH, with the millstone diameter of 6.3mm, the power of 5600 KW and is equipped with 4 rollers.

The current abroad manufacturers mainly include Loesehe Company, Fuller Company, UBE Company, FLS Company (Atox Mill), KHD Company (RM mill) and Pfeiffer Company. The domestic manufacturers have a relatively small amount, whose R&D and production are still in the developing level. However, compared with international brands, the domestic brands have some unique characteristics, which are better suited to the domestic market.

Compared with other grinding equipment, this machine has the following features.

1. High efficiency of grinding. Using the principle of material bed’s crushing and squeezing, the material is rolled, cut, impacted in the mills; the airflow in the mill can take the grinded materials out timely to avoid excessively grinded; the materials generally stay in the mill for 2-4 minutes. It has the 165% grinding efficiency as the and the power consumption can be reduced by 30% or so.

2. High drying efficiency. Hot air spray in from the annular gap with high wind speed; there is a large ventilation cross-section in the mill and the air resistance is very small. The materials with 8% moisture can be dried by the exhaust gas from preheater in the end of kiln. If there is a hot air furnace, the materials with 15%-20% water content will be dried. So it has many advantages over .

3. The feeding size can be very large and usually can be up to the length as 5% of the roller diameter. The large ball mill’s feeding size can be up to 150 ~ 200 mm. The equipment has superior technical performance and is of high capacity. It has high rate of operation and lower metal-worn than the ball mill.

4. Strong adaptability to grinded materials. It can be used to grind a variety of materials, such as limestone, sandstones (Si02 90%), coals, cement clinkers, blast furnace slags and so on. No matter the differences of raw material’s easy-grinding or abrasive, the equipment can produce qualified products with different fineness and different specific surfaces just by adjusting the internal structure and operating properly.

5. Simple process and compact layout, lower routine maintenance cost. It can be used as open-air setting and can save 70% construction investment than the ball mill.