Vertical shaft impact crusher is a kind of crushing equipment made of newer crushing concept, which is more and more popular in the field of sand making at home and abroad, also known as sand making machine. Generally speaking, there are many factors that affect the production capacity of impact sand making machines, which are mainly analyzed from the following five aspects: material characteristics, impeller speed, crusher working parameters, production line design and operation and maintenance.
01 Influence of material properties
1) Material hardness
The main factor affecting the difficulty of ore crushing in the production process is the hardness of the ore itself.
The mechanical properties of most ore materials are unevenly distributed. The materials with large lumps and many texture gaps have poor mechanical strength and are easy to be broken; and the finer the particle size, the less the internal texture gaps, the higher the mechanical strength, and the less likely to be broken. The greater the hardness of the ore, the greater its density, the greater the difficulty of crushing, the lower the efficiency, and the more serious the wear on the equipment.
2) Feeding granularity and reasonable feeding amount
Each model has a limit on the maximum particle size of the feeding material. If it is too large, it is easy to cause blockage and cause the equipment to lose its crushing function. Too much fine powder in the material will also affect the sand production. For materials with a high content of fine powder, they should be sieved once in advance to screen them out, so as not to affect the normal operation of the equipment.
While ensuring the output, the appropriate feeding amount is beneficial to improve the life of wearing parts. When the feeding amount reaches 70%~90% of the full load of the impeller, the sand production reaches its peak value. If the feeding amount is too small, it not only reduces the output of the equipment, but also increases the wear of the lining plate of the crushing chamber and shortens the replacement cycle of parts.
3) Material humidity
That is to say, when the moisture content in the material is large, the material is easy to adhere in the impact sand making machine, and it is also easy to cause blockage during the feeding and conveying process, resulting in the reduction of sand production capacity. If the humidity of the selected material is too high, sunlight or air drying can be used to reduce the percentage of moisture in the material.
4) Material viscosity
The higher the viscosity of the material, the easier it is to adhere. The material with high viscosity will adhere to the inner wall of the flow channel cavity in the impeller, and even block the flow channel. If it cannot be cleaned in time, it will affect the working efficiency of the crusher, and may also affect the normal work in severe cases. Therefore, when selecting materials, the ones with low viscosity should be selected.
02 Influence of impeller speed
The continuous material enters the high-speed rotating impeller, and after acceleration, a steady stream of power material is formed, which produces high-speed extrusion, grinding and crushing in the vortex cavity, resulting in continuous crushing production. It can be known from the working principle of the vertical shaft impact crusher that when the particle size of the material is determined, the kinetic energy increases greatly as the linear speed of the crusher rotor increases; when the linear speed of the crusher rotor is balanced, if the material mass increases, the kinetic energy increases. also increases, and vice versa.
There is a certain relationship between the particle size of the crushed stone in the vertical shaft impact crusher and the linear speed of the rotor. Under the premise of the same working state, if the particle size of the crushed material is large, the linear speed of the crusher rotor will be low. It can be seen that when the crushing strength of the material is large or the crushing particle size is small, the required crushing speed will increase. In the case of the same particle size, moisture content and feeding amount of the incoming materials, the rotor speed (line speed) of the crusher is appropriately increased, and the output of fine powder is increased.
03 Influence of working parameters
Crusher performance and structural factors have a great impact on crushing. The type and specification of the crusher, the economical and reasonable installed power, the adjustment range of the rotational speed, the size of the discharge port and the structure of the crushing cavity all have a great influence on the crushing efficiency.
For example, the crushing cavity of the vertical shaft impact crusher can be of “stone-on-stone” type or “stone-on-iron” type. The former has better grain shape and is suitable for shaping; the latter has high crushing efficiency, but the finished grain shape is slightly worse. , the wear cost of the surrounding guard plate is also higher.
Changing the form of the peripheral lining plate in the crushing chamber, or increasing the impact plate, increasing the size of the outlet of the crushing chamber, etc., can increase the production capacity and increase the amount of fine particles.
04Influence of production line design
A high-efficiency sand-making production line not only requires high-efficiency sand-making equipment, but also the coarse crushing, medium crushing, screening and washing equipment, waste water and mud treatment equipment, etc. to meet the production capacity requirements. If a certain link fails to achieve the required crushing ratio, it will inevitably cause pressure and constraints on the next stage of crushing, which will increase the number of system failure points, reduce the reliability of its operation, and ultimately the sand production of the sand making machine. decline.
05 Influence of operation and maintenance factors
The standardized operation and regular maintenance of the sand making machine will also affect the sand output of the equipment. If a sand making machine is operated irregularly and does not do regular maintenance, it will cause the wearing parts of the equipment to wear faster, greatly reduce the life of the equipment, and the production volume per unit time will be small.
For example: the continuity and uniformity of feeding have a great influence on production. Continuous and uniform feeding can not only make production normal, but also improve productivity; the size of feeding particles will also affect production, and materials larger than the specified value will cause The imbalance of the impeller and the excessive wear of the impeller will cause the impeller channel and the central feeding pipe to be blocked, so that the sand making machine cannot work normally and so on.
The vertical shaft impact crusher is a widely used sand making equipment in the current market. Its capacity is not only related to the equipment itself, but also closely related to the materials, operation and maintenance conditions, and the configuration of the production line. Users should make more comparisons when purchasing in the early stage, and choose regular and powerful manufacturers to plan and design production lines.