Traditional Sand Makers
Traditional dry sand making machines include Hammer Crusher, Impact Crusher and Cone Crusher. However, they all have the defects that high powder content, poor particle shapes, unreasonable grading, low output and fast equipment wear.
New Type Sand Makers
At present, the sand plants mainly use the new type dry sand making methods. The commonly used sand makers include 3 types: Double Shaft Hammer Crusher, Vertical Shaft Crusher and Roller Crusher.
1. Double Shaft Hammer Crusher
Double shaft hammer crusher is mainly composed of frame, crushing plate, upper rotor, lower rotor, hammer head, rotary drive device, screen plate, etc.
In the process of operation, the two rotors of the double shaft hammer crusher operate relative to each other. The materials entering the crushing chamber are first broken by the hammerhead on the first rotor and hit the second rotor after obtaining a certain kinetic energy. Because the second rotor flies in the opposite direction to the materials, at this time, the impact speed of the second rotor on the materials is equal to the superposition of two speeds, and the materials are hit by multiple cycles after crushing, it is discharged through the gap of grate bar.
- The two rotors drive the materials in the crushing chamber to collide with each other, and the repeated collision of the materials forms the self crushing of the stone in the crushing chamber, which greatly reduces the consumption of hammer head and wear-resistant parts.
- The materials in the crushing chamber are thrown out by two rotors along the tangent direction, forming repeated high-speed impact with each other, so the crushing ratio is large, the output is high, and the yield is high.
- Machine made sand has low power consumption and low operation cost.
- It takes a long time to adjust the particle size, particle grading and fineness modulus of the product by adjusting the gap of the grate.
- The controllability of product quality is not high.
2. Vertical Shaft Crusher
Vertical shaft crusher is composed of vertical shaft impact crusher, vibrating screen, dust removal module, conveying module, etc.
The vertical shaft sand making system makes the crusher have multiple effects of “crushing, shaping, sand making and grading” to achieve the best crushing particle shape, and it is equipped with vibration screening, as well as off-line ash cleaning pulse dust removal method to concentrate dust removal and collection.
The final product aggregate and finished sand are of high quality, which can realize clean production.
- Vertical shaft crusher has high crushing efficiency and little influence by the moisture content of the material. The moisture content of the feed can reach 8%.
- The product has excellent particle shape and very low content of needle and flake, which is suitable for the production of high-grade aggregate.
- The structure is relatively complex, which generally needs to be used together with vibrating screen, bucket elevator and fan.
- Due to the large number of equipment, the power consumption of the system is high and the operation cost is high.
3. Roll Crusher
Roll Crusher is a new type of sand making equipment. The material falls between the two rolls through the feeding port for extrusion and crushing, and the finished product falls naturally.
In case of over hard or non crushing objects, the roll can automatically give way by the action of hydraulic cylinder or spring, so as to increase the rolls gap, and the over hard or non crushing objects fall down, so as to protect the roll crusher from damage.
There is a certain gap between the two rolls that rotating in the opposite direction. Changing the gap can control the particle size, particle shape and fineness modulus of the product.
The double roll crusher uses a pair of round or special-shaped rolls which rotated in opposite directions to crush,
The four roll crusher uses two pairs of opposite rotating round or special-shaped rolls to carry out crushing operation.
- The roller crusher has a simple structure, and the tooth shape, size and arrangement on the roller surface can be changed according to the material properties.
- The yield is almost 100%.
- Safe and stable operation and low production cost.
- The product shape and gradation of roll crusher are better than hammer crusher, but worse than vertical crusher.
Comparison of Sand Makers