The development history of sand mill

In today's sand mill market, as the most widely used high-end refined powder grinding equipment, each has its structural design and improvement, especially the design of the dispersing disc, which is even more diverse, but it is the layout of the grinding cylinder. In terms of form, it is mainly divided into horizontal and vertical.

bead-mill for high viscosity

The development of sand mills has probably gone through the following stages:

The first stage: vertical stirring mill (bottom screen separator + rod type grinding original);

The second stage: vertical disc sand mill (disc + top screen separator);

The third stage: Vertical pin sand mill (rod type + top gap separator);

The fourth stage: horizontal disc sand mill (disc + dynamic rotor centrifugal separator);

The fifth stage: horizontal pin rod circulating sand mill (rod type + super large filter area separator).

Horizontal Bead Mill

The invention of the vertical sand mill improves the shortcomings of the vertical agitating mill such as low rotation speed, large media size, low grinding efficiency, and wide product particle size distribution so that the grinding equipment market has completely entered the era of sand mills.

However, due to the structural limitations of the early vertical sand mills, there were some problems, such as the low filling rate and uneven distribution of the grinding media under the influence of gravity. After avoiding these shortcomings, it quickly squeezed the market and gradually became the mainstream of fine grinding equipment.

But this does not mean that the vertical sanding machine will be replaced. There is still room for optimization and it has its unique advantages. Compared with the traditional horizontal sand mill, the vertical sand mill with this structure design can effectively solve the leakage of shaft seal damage, the blockage of the bead grading network, the inability to grind with ultra-fine beads, the uneven product particles, and the low production efficiency. The five major problems of high consumption.

bead mill

How to solve the shortcomings of traditional vertical and horizontal sand mills through structural optimization and improvement?

1. Feeding and discharging materials are different from traditional horizontal machines. The feed is conveyed to the grinding cavity by driving the screw thread, and the material is extracted from the grinding cavity by the suction of the pump when the material is discharged. No additional mechanical seal is required, and the leakage and pollution problems caused by the damage of the shaft seal are prevented from the root cause.

2. The grinding process makes full use of the principles of centrifugal classification and fluid mechanics. The grinding chamber is divided into two grinding zones inside and outside by the stirring rotor, inner stator, and classification turbine. The raw material particles will undergo centrifugal classification inside for classification and grinding, and the materials and beads are also separated by centrifugation.

3. The grading cycle grinding enhances the grinding effect. The material first enters the outer grinding zone and moves along the outer grinding void between the rotor and the cylinder along with the beads. After reaching the bottom, it moves along the inner grinding zone between the rotor and the inner stator to near the axis and then moves there. The role of two classifications. Finally, the small particles are discharged to the outer circulation cylinder in time, and the large particles are discharged to the outer grinding area to continue to participate in the next grinding cycle, which not only prevents the over-grinding of the small particles, but also increases the grinding times of the large particles, and the final product size The distribution span is small.

This method of centrifugal force classification solves the problem of screen clogging, and the classification grinding also effectively utilizes vertical gravity to allow the raw material particles to circulate up and down inside, lengthening the grinding channel and also allowing the particles to be more uniformly dispersed. Better grinding effect. In the whole grinding process, the equipment energy is mainly used for the effective grinding of large particles, which maximizes the useful work of the equipment, realize high-efficiency and energy-saving grinding, and improves the grinding efficiency of the equipment.


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Source: Franli

This article address : The development history of sand mill