Vertical Roller Pre-grinding Mills

The Ideal Choice

For Upgradation and Greenfield Grinding Project: Clinker and Raw Meal

The Vertical Roller Pre-grinding Mills developed by AMCL Machinery Limited are based on technical knowhow from Nihon Cement Co. Ltd. Japan. These machines are used for substantial power saving and capacity enhancement in the field of Clinker and Raw meal Grinding. We have over two decades of experience in supply and installations of Vertical Pre Grinding Mills. We have supplied over 30 Installations in India & Middle East.

Efficient Principle of Operation

Compressive & Shear force act simultaneously on material results high grinding efficiency

Clinker or Limestone is fed through a central chute in the VRPM where rotation of the table generates centrifugal force which causes material to spread over the table in uniform layer. Material is caught between rollers & table and subjected to very high compressive Stress. Compressive stresses produces crushing action on the clinker. Friction causes Roller and Table to rotate synchronously generating shearing stresses. Shearing stresses produces grinding action on the clinker. A grinding force is transmitted to a set of three rollers at 120 Degree apart through a hydraulic system. The table and rollers then grind the material, which is then extracted from the VRPM by gravity and a little help from a scrapper.

Sturdy Constructional Features

Swing-out feature provides easy maintenance and reduce down time

Rollers

Roller type is made from special alloy steel castings and are confirming to Nihon Cement Specification AT-C for wear resistance. Special alloy high chrome iron casting roller tyre for life 10,000 hours in clinker and extend its longevity due to shape of Roller. Shaft made out of special alloy steel duly hardened tempered and ground. Roller shafts are clamped to the journal head which are hinged to the spindle. Grinding Force is provided by hydraulic cylinder transmitted to Roller.

Grinding Table

The grinding table made out of high grade cast steel is directly mounted on gear box output Flange. Generally expected life of table liners will be 14,000 hours in clinker.The upper surface of the table is fitted with table liner segments constructed of special wear resistant cast steel and held in place with retainer ring. The table liner is divided into segments for ease of handling. A scrapping paddle is installed below the table and the paddle is driven by rotation of the table.

Salient Features of VRPM

High efficiency spherical mechanism

The centrifugal force generated by rotation of the table spreads material across the entire table surface in a uniform layer, where it is caught between the roller and table liner segments and crushed before being carried to outer circumference of the table. The grinding force is transmitted by roller at the same time through a hydraulic system. Rollers also offer high compressive force between table and roller which generates greater shearing force. Therefore high efficiency grinding is carried out by simultaneous compression and shearing force.

Uniform grinding

As rollers have higher periphery, a wider uniform grinding layer is formed and hence increases grinding efficiency.

Fluctuation in feed can be accommodate

Fluctuation in feed is handled by controlling rotation of table and does not affects fineness of material.

Fluctuation in raw material grindability can be accommodate

In VRPM adjustment in product fineness by adjusting Hydraulic Pressure on roller or by changing height of dam ring.

Possible Configurations

Several Configurations are possible, such an as open circuit mill, close circuit mill and feeding to more than one Ball Mills.

Compactness

VRM is very compact hence require little space. It can be accommodated easily in existing plants.

Various Model Range Suit The Customer Requirement

Model	Roller Diameter (mm)	Roller Width (mm)	Table Diameter (mm)	Drive Motor (KW)	Capacity (TPH) <-2 mm
VRPM 150-3	900	315	1500	550	60-75
VRPM 180-3	1160	400	1800	800	90-120
VRPM 230-3	1400	500	2300	1250	150-170
VRPM 270-3	1760	590	2700	1850	240-260

Key Benefits

A profit optimizer

Low maintenance

We offers VRPM with swing out feature to allow easy replacement of Roller Tire. In addition to that VRPM is a non air swept mill therefore wear and tear is low comparative to air swept Mills.

Reduction in specific Power consumption

We offers VRPM with combination of existing or new ball mill where efficient course grinding takes places by means hydraulic press applied by roller on material, allows to reduce work done by ball mill result in reduction in specific power consumption of overall grinding circuit.

Increase in production capacity

By means VRPM, we fed pre-ground material to the ball mill where fine grinding takes places thus results in increase in production capacity.

Long Life for table liner and roller

Spherical shaped roller and uniform gap between roller and table extends the life of roller and table liners.

Less floor space required

Our system engineering experience allows such to integrate the VRPM along with existing Ball Mills within limited space specially for the brownfield projects.

Application

Upgradation / Brownfield Projects

Clinker grinding / Raw Material Grinding

VRPM can be integrate with existing Cement Mill circuit to have substantial saving in specific power consumption and increase in production capacity. We have experience of system engineering & layout engineering which allows us to install the VRPM circuit within limited space in existing plant.

Highlights:

Saving in Specific power consumption.
Capacity increase from 50% to 90 %.
Higher Blaine is possible.
Less maintenance required.
Can be accommodate in limited space.

Greenfield Projects

Clinker grinding / Raw Material Grinding

We also offers combination of VRPM and Ball Mills along with single separator system to reduce no. of equipment in circuit which result in reduction of overall project cost. This circuit allows to get homogenized product from single dynamic which reduces logistic of the material.