The impact crusher’s ability to selectively crush materials during the impact process enables it to have more cubic crushed product content than other types of crusher manufacturers, as shown in Table 1. It also has the characteristics of large crushing ratio and simplifies the crushing process. Therefore, it has developed rapidly in the crushing industry and is widely used in various related industries.
1. Impact crusher
The so-called impact crushing means that the object is subject to impact force in a free state and is crushed along its natural cracks, bedding surfaces, joint surfaces and other weak parts. Broken by selective crushing (as shown in Figure 3). It is different from hammer crushing in which the object is subject to the impact force in a restrained state, as shown in Figure 4, and also different from other shearing, compression, grinding and crushing, so it consumes the lowest energy during the crushing process, and due to its The ability of selective crushing plays the role of monomer separation of useful minerals and obtaining more cubic products.
Impact crushers that apply the impact principle use a high-speed rotating hammer to impact the materials in the crushing cavity at high speed, causing the materials to be impacted and broken, and the impact materials to be crushed at high speed. Towards the impact plate, after the material is impacted and broken again, it bounces back from the impact plate back to the impact area of ??the hammer head to repeat the above crushing process. At the same time, the materials still have collision and impact effects on each other during the back and forth between the hammer head and the impact plate. . When the particle size of the crushed material is smaller than the gap between the hammer head and the impact plate, it will be discharged from the lower part of the machine and become the crushed product.
The crushing energy of materials of different particle sizes is different. The smaller the material, the greater the energy required for crushing due to the gradual reduction of internal defects. According to the relationship formula between energy and linear velocity: A = mra.
With the improvement of mining capacity, the size of the material blocks after mining continues to increase. This series of double-roller impact crushers can be used in industrial sectors such as mineral processing, chemical industry, cement, refractory materials, abrasives, and building materials. It is used to finely crush various high and medium hardness ores and rocks, especially in the production of products such as guar rice stone and mung bean paste in the building materials industry. It has better results than ordinary crushing machines. , while the single-rotor impact crusher limits the increase in feed particle size due to its structural rationality and other reasons, so the dual-rotor impact crusher was developed. In order to improve the effect of the second rotor, a double-rotor impact crusher with a height difference setting was developed. According to the relationship between hammer head wear and energy consumption and the linear speed of the rotor, the first one coarsely crushes the material at a lower speed. , Impact crushing This series of double-roller crushers can be used to finely crush various high and medium hardness ores and rocks in industrial sectors such as mineral processing, chemicals, cement, refractory materials, abrasives, and building materials, especially in the production of melons in the building materials industry. Products such as rice stone and mung bean paste have better results than ordinary crushing machinery. , while the second rotor performs medium and fine crushing of materials at a higher speed, improving the crushing ratio.
The vertical impact crusher is a representative of the impact crushers used for fine crushing of materials. We know that the wear of the hammer head increases non-linearly with the increase in the linear speed of the hammer head rotation. During fine crushing, the linear speed of the hammer head is very high, and relatively light materials cannot enter the effective striking zone of the high-speed rotating hammer head ( Just within the maximum linear speed range), resulting in reduced crushing effect and increased wear of the hammer head. The vertical impact crusher adopts the center feeding method. After the material is fed, the initial speed is close to zero. After gradually accelerating, it is ejected from the rotor body for impact crushing, which improves the impact crushing effect and reduces the wear of wearing parts. . This kind of crusher has evolved into two categories: mechanical type and self-lining type.
2. Impact Crusher
As mentioned above, in actual use, the impact crusher has uneven discharge and is easy to break away large pieces. The impact hammer Type crusher can solve these problems easily.
The material is fed into the machine from the feed port, enters the working area of ??the hammer head, and is crushed by the impact of the high-speed rotating hammer head. At the same time, the material hits the impact plate at high speed and is further broken. It bounces back from the impact plate to the working area of ??the hammer head, continues to repeat the above crushing process, and finally enters the hammering area (the working area between the hammer head and the grate bar), where it is further hammered and grinded by the hammer head. . Practice has proved that the material is not fully crushed in one cycle of the rotor, but needs to go through multiple cycles to be fully crushed.
Large pieces of material may not be fully broken during the impact process. They can be broken through the rolling action between the impact plate and the hammer plate. This effect has been confirmed by actual experiments (in the absence of grating bars, the jaw crusher Machine Crusher Price Crusher This series of double-roller crushers can be used to finely crush various high and medium hardness ores and rocks in industrial sectors such as mineral processing, chemicals, cement, refractory materials, abrasives, and building materials, especially in the building materials industry. It has a better effect than ordinary crushing machinery in producing products such as guar rice stone and mung bean paste, and its maximum product particle size does not exceed the gap size between the hammer plate and the impact plate).
3. Impact hammer crusher This series of double-roller crushers can be used to finely crush various high and medium hardness ores and rocks in industrial sectors such as mineral processing, chemicals, cement, refractory materials, abrasives, and building materials. Especially in the building materials industry to produce products such as guar rice stone and mung bean paste, it has better results than ordinary crushing machinery. Structural type
The impact hammer crusher manufacturer is mainly composed of four parts: the body, the rotor, the grating body and the transmission device. Below is a brief description of each of these four parts.
3.1 Body
The basic type of body is shown in Figure a.
Its main function is to support the rotor and grate body to crush materials and ensure a large enough crushing cavity to fully crush materials. In addition, in order to prevent materials from abrading the inner wall of the machine body, lining boards are laid on the inner walls of the machine body that are prone to wear. The counterattack plate should be able to be opened to the appropriate position (the opening and closing of the counterattack plate for small-sized machines is completed by a crane, and for large-sized machines, it is completed by a hydraulic system) to facilitate the replacement of the counterattack lining plate and other lining plates. The hammer head can be replaced after opening the access cover. In addition, the grating body can be removed and replaced by opening the access door. Open the observation door to check the gap between the hammer head and the grating bar and the wear of the hammer head.
, provides a basis for selecting excellent anti-wear materials.
3.2 Transmission device
Its function is to drive the rotor with dynamic and static torque and accelerate the rotor with large torque. Usually the V-belt transmission method is used: winding motor ~ pulley, rotor. This transmission method can obtain a higher starting torque under a smaller starting current, absorb the vibration generated when the crusher is working, and has a certain load-bearing capacity and overload capacity. The pulleys are all connected by expansion sleeves, which are convenient for loading and unloading and have overload protection. In addition, the large pulley on the rotor also serves as a flywheel to ensure the rolling effect between the hammer plate and the impact plate.
3.3 Rotor
The rotor is the main crushing tool of this machine, with the general structure type and arrangement of hammer heads.
3.4 Grain bar body
The grate bar body is the carrier body for the material to withstand the hammering, and at the same time it is the restriction body for the particle size of the product discharged by the material. It has two structures: grate plate and grate bar. The penetration of the latter is very important.
The placement of the counterattack plate and the design of the counterattack lining structure Mainly based on the working principle of the impact hammer crusher, it ensures the impact effect of the impact plate and the rolling effect between the impact plate and the hammer plate. In similar machines at home and abroad, the counterattack plate located above the grate body has a convex part Q with a width of K. Since the upper edge of the support plate of the grate body is higher than the grate bar, it is in direct contact with the material and is easy to wear. In order to reduce wear, a convex part Q is added to the counterattack lining plate. This part is just aligned with the upper edge of the support plate and mainly plays a protective role. The grate body structure designed by our company is different from the above structure. The briquette machine is a high-efficiency fine crusher. Third-generation sand making machine, new sand making machine, fine crusher, price, manufacturer - Zhengzhou Zhongbang Machinery Engineering Co., Ltd. Crusher This series of double-roller crushers can be used for mineral processing, chemical industry, cement, refractory materials, abrasives, and building materials It is used to finely crush various high and medium hardness ores and rocks in other industrial sectors, especially in the building materials industry to produce products such as guar rice stone and mung bean paste. It has better results than ordinary crushing machinery. , so the counterattack lining produced by our company has no protruding part Q, thus simplifying the casting process and reducing costs.
IV. Determination of the main working parameters of the impact hammer crusher
The main working parameters of the impact hammer crusher include linear speed, output and motor power.
4.1 Linear speed
The linear speed of the impact hammer crusher is based on the nature of the material, crushing ratio requirements, machine structure and other factors, and after comprehensive consideration of the wear of the hammer head selected.
The increase in linear speed increases the impact speed and increases the chance of impacting the material, which helps to obtain finer product particle size and improve production capacity. However, too high linear speed prevents the material from entering the effective striking area of ??the hammer head, causing the sleeping head to have more of a cutting effect on the material, increasing the wear of the hammer head, and reducing the energy utilization rate.
Reducing the linear speed can reduce the wear of the hammer head, but at the same time it increases the contact probability between the material and the hammer plate, increasing the wear of the hammer plate. The selection of linear speed is a process of comprehensive consideration. In view of the fact that it is also limited by the hammering, grinding, and cutting effects between the hammer head and the grate bar body, it is more appropriate to select a linear speed between 30^-40m/s.
4.2 Output
There are many factors that affect output, such as: crushing ratio requirements, rotation speed selection, physical properties of materials, particle size distribution, machine structure, etc. .
4.3 Motor power
In addition to considering factors such as material properties, crushing ratio, processing capacity, etc., the determination of power should also consider the large moment of inertia of the rotor body when the hammer head is asymmetrical during the startup stage. Effect on power. In addition, the determined power can meet the requirement that the hammer head consumes all the energy in one impact and crushes and finally recovers quickly.
5. Determination of the basic structural parameters of the impact hammer crusher
5.1 The diameter and length of the rotor body
The diameter of the rotor body is related to the maximum feeding particle size . According to the impact principle, the size of the feed particle size is directly proportional to the mass of the impact hammer, and is closely related to the effective striking height of the hammer head (that is, the height at which the hammer head exposes the rotor body). In addition, considering that there is a certain amount of rolling action during the working process of the impact hammer crusher, it must have sufficient rotational momentum, which requires the diameter of the rotor body to increase as the feed particle size increases.
Usually, the ratio of the diameter of the rotor body to the maximum feeding particle size is 2^-4, which is smaller for large machines. The length of the rotor is determined according to the production capacity.
S.2 Hammer head
a. The shape of the hammer head and the height h of the hammer head exposed from the rotor body.
When designing, the crusher uses an impact crusher. This series of double-roller crushers can be used to finely crush various high and medium-sized materials in industrial sectors such as mineral processing, chemicals, cement, refractory materials, abrasives, and building materials. It is used for hard ores and rocks, especially in the building materials industry to produce products such as guar rice stone and mung bean paste. It has better results than ordinary crushing machinery. In principle, the working surface of the hammer head should pass through the rotation axis of the rotor, as shown in Figure 14, to achieve the frontal impact of the hammer head on the material. Slight deviations are allowed taking into account wear compensation or hammer head weight limitations. The design of the arc surface at the end of the hammer head should consider introducing the bite angle a, as shown in Figure 14. This article recommends a range of 5 to 100. Excessive bite angle causes premature wear of the hammer head and reduces the service life of the hammer head. The arc length is mainly determined based on the corresponding hammer shaft diameter and suspension arm thickness required in terms of strength for different hammer head weights. The strength assessment of the hammer shaft and suspension arm can be calculated based on the force situation when the hammer head is in balance in the working state, and the centrifugal inertia force of the hammer head when working is used as the load for verification.
The height h at which the hammer head exposes the rotor body is also the effective striking height of the hammer head. From the perspective of impact effect and production capacity, we hope that h is large, especially for large pieces of material. To achieve ideal impact, h must be very large. Theoretically, if the impact force on the material block happens to pass through the center of gravity of the material block, the impact effect will be best. Taking into account the rationality of structural design and the increase in power consumption, the increase in people must be appropriate. At the same time, people cannot be too small. Too small h increases the grinding effect of the hammer head on the material, which not only affects the processing capacity of the crusher but also aggravates the wear of the hammer head.