# Structure and technical parameters of High-Pressure Grinding Rolls

High-Pressure Grinding Rolls have a wide range of applications, such as:

1 . Medium, fine and fine grinding down loose materials.

2 . The beneficiation industry can be arranged before the ball mill , as a pre-grinding device , or as a hybrid grinding system with a ball mill.

3 . The oxidized pellet industry can replace the commonly used grinding machine.

4 . Building materials, refractory materials and other industries have been successfully applied to cement clinker, limestone, bauxite and other grinding.

When you are ready to buy a high-pressure roller , it is recommended to first understanding its basic structure and parameter comparison for your future use .

1 . Clamp angle . Two tangent lines are respectively drawn from the point of contact between the spherical material and the roller , and their angle is called the clamp angle of the high pressure roller mill . The relationship between it and the discharge gap is : where e is the gap width of the two rolls (mm ) ; D is the diameter of the roll (mm ) ; η is the material compaction , which can be calculated by the volumetric output V of the high pressure roll mill : V = ηeLv , where V is the volumetric yield (m3/h ) of the high pressure roll mill ; L is the roll length (mm ) ; v is the material velocity , (m/s ).

2 , roller size . The roller length of diameter ratio (L/D ) is called the geometrical parameter of the high pressure roller mill . For the same material , the larger the size , the greater the production capacity . For mills with similar or identical geometric parameters (longitudinal to length ratio ) , the same pull-in conditions and line speeds , the mill output is proportional to the square of the roll diameter . The length of the roller is relatively small . According to the statistics , the length-to-diameter ratio of the roller is generally : L/D=1/3~1 .

3 , two roll gap width . The ratio (e/D ) of the gap width e of the two rolls to the diameter D of the rolls is referred to as the relative gap width , and the ratio is 0.01 to 0.02 , that is , the gap width of the two rolls is about 1% to 2% of the diameter of the rolls . The width of the roller gap is related to the material passing density of the mill . The larger the gap is , the larger the throughput is . Therefore , the roller gap design is adjustable , depending on the material properties (hardness , shape , structural characteristics , etc . ) , humidity , particle size composition , Larger feed size , material and friction between the rolls and other factors . The gap width of the two rolls is generally 6 to 12 mms .

4 , larger feed size . The larger feed size dmax has the following relationship of / to / between the roll diameter : dmax = (0.07 ~ 0.08 ) . D When a smooth roll is used , the content of the material (dmax ) larger than the gap width e in the feed should be less than 20% , and the ratio should be less than 3 . The general feed size is less than 50 mms and the larger are up to 80 mms .