عدد المساهمات : 1713
السٌّمعَة : 1
تاريخ التسجيل : 26/08/2011
|)impact (hammer crusher)|| |
Cement plant material prepared by the crushing and grinding operations to achieve, "little more than break the ground", "to break instead of grinding" is a proven production practices have been the major energy-saving measures. Back in the 1960s, a number of industrialized countries have adopted more crusher than 4O ever need to replace the crusher machine three-stage crusher operations, this crushers can reach the maximum feed size l ~ 2m, the material is generally less than 25ram, directly into the ground, some even crusher limestone and clay mixed material. Thus greatly simplified the production process to achieve the savings in investment, reduce energy consumption and other production costs Use, ease of management purposes.
2 crushers to determine the main parameters
Process requirements under the cement plant, crushers specifications should be able to meet the appropriate scale of production crusher process line crusher limestone, gypsum, phosphate, rock salt, marl salt, hard coal and other needs.
2.2 line speed
In the single-stage hammer crusher, hammer on the one hand, the material in order to increase access to smaller particle size against hope that the rotor has a higher rotation speed, on the other hand due to its initial approach is to rely on Crushed hammer plate to support care material block, and they have a large relative motion, While the material wear and nearly proportional to the square of the speed relationship (Figure 3). This decision can only be applied at a moderate rotation speed. crushers Study concluded that the hammer speed 3O ~ 40mm / s is the priority number. With the same kinetic energy conditions, the wear is the key. Therefore, organic materials and metal-induced wear introduce the concept of design is essential.
2.3 determine the power
Still no more accurate formula for single-stage hammer crusher power calculation. Testing and production that, in normal working condition and size of installed power production capacity is proportional to the crushers. Common design principles at home and abroad is based on a large number of unit power consumption statistics.Material to determine the power of the crushers. However, the mere selection by the potential failure factors are often the choice of crushers power must consider the following factors to determine:
(1) Should be able to meet normal operating conditions of the breakers rated power needs.
(2) Ensure Crusher normal starting load conditions. Because the hammer broke Xi large rotor body inertia, acceleration torque rotary hammer is also big and full start-up phase rotation in the quality of non-symmetry, shown in Figure 4.
(3) Too large to fit the material into the crushing chamber is crusher and immediately after discharge. Because the hammer crusher is not covered under the work of feeding conditions.
2.4 the distribution of ratio of crusher
Single-stage Hammer Crusher Impact crushing mechanism is added roll. From the feed particle size distribution curve can be seen (Figure 5), less than the diameter d of the material block (shaded area A). Its weight is less than the energy of the hammer can be crusher, hammer into the work area, had been largely expected to block the hammer aligned
Center of mass is hit and crusher, as shown in Figure 6. Part of the material is greater than the d block, fall into the hammer area, hammering point below the center of mass, only a block from the material on the perimeter to knock down (Figure 7), while the edge to bite into the area to scroll. End plate and back plate by a hammer consisting of a single roller crusher roll break Crushed (Figure 5, area A). Change the back plate of the angle n. Type of impact can be crusher and the roller to adjust the proportion.
2.5 crusher product size
crusher grain products should be combined with grinding practices comprehensive determination. People often from personal experience, simply as a crusher product size 10 ~ 25mm or 1 5ram, without any proof. Some designers refer to B.A Shah Watkins chart data, but he gave Chart out the requirements of technical conditions, in the actual production is difficult to achieve (see Figure .
For the crusher and the final product particle size distribution can affect the efficiency of the grinding work on the subject, the United States smash the experience of experts C.A Rowland according FCBond best to put forward a ball mill particle size formula:
F= Feeding Size
W= Ball mill work index
If the particle size more than feeding the best value, the mill's grinding effect will be reduced. Mill's power will increase, the increase can be calculated multiples
EF4 =([R+（W-7）]+((F-F_n)/F_c ))/R
EF4 - Feeding size affects ball mill power factors, R - Production ratio, R= F_gu/ P_gu, W = Work index
F_gu - 80% of the feed materials through the sieve size
P_gu - 80% of the product over the mesh size can
J.C.Farrant and R. North, said: "When the production of more detailed work of crusher products more expensive to make and crusher more complex, and when treatment coarse-feed grinding work efficiency is low, crusher into from the most economical grain mill degree of the problem to occur naturally. "