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Set up a competitive bridge between impact crusher and hammer crusher

ren

Hortense

2020-07-20 06:57:54 1151

Set up a competitive bridge for impact crushers and hammer crushers. With the gradual penetration of the reform process, the increasing development of infrastructure and road engineering has promoted the demand for building materials such as concrete aggregates and cement, and proposed changes. High standards.

For concrete aggregates, foreign research data shows that cube materials can save the amount of cement under the same compressive strength when making concrete. At the same time, when the amount of cement is the same, the amount of cement is increased. The strength and density of concrete. The selective crushing ability of the impact crusher on the material during the impact makes it have more cubic crushing product content than other types of crushers, as shown in Table 1, at the same time It has the characteristics of large crushing ratio and simplifies the crushing process, so it has developed rapidly in the crushing industry and is widely used in various related industries.

An impact crusher



The so-called impact crushing refers to the object being hit in a free state and selectively crushing and crushing along the weak parts such as the natural fissure bedding surface and joint surface (as shown in Figure 3). It is different from the impact force of the object in the constrained state in the hammer crushing, as shown in Figure 4, and it is different from other shearing, pressure grinding and crushing, so the energy consumption in the crushing process is low, and due to its selectivity The crushing ability plays a role in separating useful minerals from the monomer and obtaining more cubic products. The impact crusher that applies the impact principle uses a high-speed rotating hammer to impact the material in the crushing cavity at high speed, so that the material is generated. The impact is broken and the impacted material block is rushed to the impact board at high speed. After the material is impacted and broken again, it rebounds from the impact board to the hammer striking area to repeat the above-mentioned crushing process, and the material is between the hammer and the impact board. In the round trip, there is also a collision and impact effect between each other. When the 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 to be the crushed product. For materials of different sizes, they are crushed. The energy is different. The smaller the material is due to the gradual reduction of internal defects, the greater the energy required for its crushing. According to the relationship between energy and linear velocity: Amra.

With the mining capacity With the improvement of digging, the size of the material block continues to increase after mining, and the single-rotor impact crusher limits the increase in the feed size due to its rational structure and other reasons, so the dual-rotor impact crusher has been developed. In order to improve the second rotor The role of the two-rotor impact crusher with height difference settings has been 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, and the second rotor The medium and fine crushing of materials at a higher speed improves the crushing ratio. The vertical impact crusher is a representative of the impact crusher used in the fine crushing of materials. We know that the wear of the hammer is related to the rotation of the hammer. The linear velocity increases nonlinearly, and the linear velocity of the hammer head is very high during fine crushing, and relatively light materials cannot enter the effective striking area of the high-speed rotary hammer (just in the higher linear velocity range), resulting in crushing The effect decreases and the wear of the hammer head increases. The impact crusher adopts the center feeding method, the initial speed of the fed material is close to zero, and it is gradually accelerated and then projected out of the rotor for impact crushing, which improves the impact crushing effect and reduces the wear of vulnerable parts. This kind of crusher has evolved into two categories: mechanical and self-lining.

Two impact crushers

As mentioned above, impact crushers exist in actual use. The discharging is uneven and large pieces are easy to run. The impact hammer crusher can solve these problems. The material is fed from the feed port into the machine, enters the hammer working area, and is impacted by the high-speed rotary hammer. At the same time, the material is further broken by high-speed impact on the counterattack plate, and bounces from the counterattack plate back to the hammer head working area, and continues to repeat the above-mentioned crushing process, and finally enters the hammering zone (between the hammer head and the grate bar). Working area), the grate bar is further hammered and ground by the hammer. Practice has proved that the material is not fully crushed in one cycle of the rotor, but must be fully crushed after multiple cycles. Large pieces of material may be In the impact process, it is not sufficiently broken. It can be broken by the rolling action between the counterattack plate and the hammer plate. This effect has been confirmed by actual experiments (in the absence of grate bars, the product size does not exceed the hammer plate The size of the gap between the impact plate and the impact plate).

Structural type of the three-impact hammer crusher

The impact hammer crusher is mainly composed of the rotor bar body and the transmission device. Part composition. The four major parts are briefly described below.

3.1 Body

Its main function is to support the rotor and the grate bar to realize the crushing of materials. And ensure that there is a large enough crushing cavity to fully crush the material. In addition, in order to prevent the material from wearing the inner wall of the machine body, a liner is laid on the inner wall of the machine body that is easy to wear. The counterattack plate should be able to open to the appropriate position (small size machine counterattack The opening and closing of the plate is completed by the crane, and the large-size machine is completed by the hydraulic system), which is convenient to replace the counterattack lining and other linings. After opening the inspection cover, the hammer can be replaced. In addition, the grate bar can be opened by opening the inspection door. Remove and replace the grate bar. Open the observation door to check the gap between the hammer head and the grate bar and the wear of the hammer head.

3.2 Transmission device

Its function is to control movement and static. The torque sub accelerates the rotor with a large torque. The V-belt transmission method is usually used: winding motor pulley, rotor. This transmission method can obtain a higher starting torque under a small starting current, and absorb the production generated by the crusher. Vibration, there is a certain load capacity and overload capacity. The belt pulley is connected by an expansion sleeve, which is convenient for loading and unloading, and has an overload protection function. In addition, the large pulley on the rotor serves as the take-off wheel to ensure the rolling effect between the hammer plate and the counterattack plate. br/>
3.3 Rotor

The rotor is the main crushing tool of this machine, the general structure and the arrangement of the hammer head.

3.4 Grate body
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The grate body is the material to withstand hammering The carrier body is also a constraint body for the particle size of the product discharged. It has two structures: grate plate and grate strip, the latter has a significantly higher penetration rate than the former, and is more widely used. The placement and counterattack of the counterattack plate The design of the liner structure is mainly based on the working principle of the impact hammer crusher to ensure the impact effect of the impact plate and the rolling effect between the impact plate and the hammer plate. The impact plate located above the grate bar in the same type of machine at home and abroad has The convex part Q has a width of K. Because the upper edge of the grate bar body support plate is higher than the grate bar, it is in direct contact with the material and is easy to wear. In order to reduce wear, the convex part Q is added to the counterattack liner, which is just right with the support The upper edge of the board is aligned, mainly for protection. The grate bar structure designed by our company is different from the above structure, so the impact liner produced by the company has no convex part Q, which simplifies the casting process and reduces the cost.

The determination of the main working parameters of the four impact hammer crusher

The main working parameters of the impact hammer crusher include line speed output and motor power.

4.1 Linear speed

The linear speed of the impact hammer crusher is selected according to the nature of the material and the requirements of the crushing ratio of the machine structure and other factors, and is selected after comprehensive consideration of the wear of the hammer. The increase in linear speed, Increasing the impact speed, increasing the chance of hitting the material, helping to obtain a finer product particle size and improving production capacity. However, too high line speed prevents the material from entering the effective striking area of the hammer, so that the sleeping head is against the material The function is more in the state of cutting bi!, which increases the wear of the hammer head and reduces the energy utilization rate. Reducing the linear speed can reduce the wear of the hammer head, but at the same time increases the probability of contact between the material and the hammer disc, and increases The wear of the hammer disc. The selection of the linear velocity is a process of comprehensive consideration. In view of the fact that it is also limited by the hammering and grinding cutting action between the hammer head and the grate bar body, the linear velocity is more appropriate to choose between 30^40ms. br/>
4.2 Output

There are many factors that affect the output, such as: the physical properties of the material selected for the required speed of the crushing ratio, the structure of the particle size distribution, and so on.

4.3 Motor power

In addition to considering factors such as material properties, crushing ratio and processing capacity, the determination of power should also consider the large moment of inertia of the rotor body when the hammer is asymmetrical during the starting phase. In addition, the determined power can meet the requirements of the hammer head to quickly recover after the energy consumed by one impact crushing.

Five impact hammer crusher basic structure parameters determination

5.1 The diameter and length of the rotor body

The diameter of the rotor body is related to the maximum feed size. According to the impact principle, the size of the feed size is proportional to the quality of the impact hammer and is proportional to the hammer The effective blow height (that is, the height at which the hammer head exposes the rotor body) is closely related. In addition, considering that there is a certain rolling effect during the working process of the impact hammer crusher, it must have sufficient rotation capacity, which requires the rotor body diameter of It increases with the increase of the feed size. Generally, the ratio of the diameter of the rotor body to the maximum feed size is 2^4, and the mainframe is smaller. The length of the rotor is determined according to the production capacity.

5.2 Hammerhead

a. The shape of the hammerhead and the height of the hammerhead exposed to the rotor body h. When designing, the working surface of the hammerhead should pass through the rotation axis of the rotor in principle , As shown in Figure 14, to achieve the frontal impact of the hammer head on the material. Considering the compensation of wear or the limitation of the weight of the hammer head, it can be slightly deviated. The design of the arc surface at the end of the hammer head should consider the introduction of the occlusal angle a, As shown in Figure 14.

This article recommends a to be 5-100. Excessive bite angle causes the hammer head to wear in advance and reduces the life of the hammer head. The length of the arc is mainly based on different hammer heads. The weight is determined by the corresponding hammer shaft diameter and the thickness of the suspension arm required by the strength. The strength assessment of the hammer shaft and the suspension arm can be calculated according to the force when the hammer is in equilibrium under the working state, and the hammer The centrifugal force of inertia at work is checked as the load.

The height h where 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, it is hoped that h is large, especially for large For a block of material, to achieve an ideal impact, h must be very large. In theory, if the impact force of the block passes through the center of gravity of the block, the impact effect is good. Considering the rationality of the structural design and the increase in power consumption, human The increase must be appropriate. At the same time, the person cannot be too small, too small h increases the grinding effect of the hammer head on the cutting of the material, which not only affects the processing capacity of the crusher, but also increases the wear of the hammer head.

Six conclusions

Because the hammer crusher combines the structure of the hammer crusher and the crushing principle of the impact crusher, it has a high crushing ratio and uniform discharge size The impact hammer crusher designed and produced by our company absorbs and digests various types of impact hammer crushers at home and abroad, and has designed a new rotor and grate bar body structure, so that the hammer head is full length in the length direction of the rotor. Participating in the attack has increased the production capacity. Compared with the same model of the German OK company, the output has increased by about 30%. At the same time, the special castor bar structure not only ensures the performance of the structure, but also reduces the requirements for process processing and improves the caster. The utilization rate of the bar extends the service life of the bar, and greatly reduces the cost of the whole machine and spare parts.

The impact hammer crusher combines the structure of the hammer crusher and the impact crusher. The crushing principle of the machine has a high crushing ratio and uniform discharge particle size. On the basis of absorbing and digesting various types of impact hammer crushers at home and abroad, a new rotor and grate bar body structure is designed to make the hammer head in The full length of the rotor is involved in the blow in the length direction, which improves the production capacity. Compared with the same model of the German OK company, the output is increased by about 30%. At the same time, the special grate body structure not only ensures the performance of the structure, but also reduces the processing The requirements have improved the utilization rate of grate bars, prolonged the service life of grate bars, and greatly reduced the cost of the whole machine and spare parts.