The application of middle crushing roller crusher in open pit mine
Date：2019-08-05 16:32 Source：未知Views:
In recent years, with the transformation and upgrading of the coal industry, the requirements for efficient coal development and environmental protection are increasing day by day. More and more lignite produced by open-pit coal mines is sold to coal chemical enterprises for further processing.In the field of coal chemical industry, the particle size of products is extremely strict, generally requiring the particle size between 25 and 70 mm, if the particle size is too large, it will block the furnace, unable to carry out further processing.
Toothed roller crusher is currently used in coal crushing more mature products, because of its processing capacity, over-crushing rate is low, by the majority of coal users recognized.However, in view of the special problem of frozen block material crushing in open-pit mine and the special low-temperature working environment, the existing toothed roller crusher is not suitable. It is urgent to optimize and improve the original toothed roller crusher on the basis of the original toothed roller crusher, so as to adapt to the medium crushing operation of open-pit mining materials and ensure the normal production of coal mine.
1 tooth roll crusher structure
Toothed roll crusher generally adopts double motor drive, through the two motor, coupling and reducer drive system, two separate rotates separately running gear roller to break bulk material, speed reducer and the broken tooth roller USES the coupling between transmission torque, the broken tooth roller respectively connected with transmission system on the overall frame, maximum limit reduces the vibration of the equipment.
2. Broken tooth roll structure
The traditional tooth roll crusher with the particle size of 70 mm generally adopts the tooth ring structure or tooth plate structure.The tooth ring is stable in structure and high in reliability. The disadvantage is that the broken teeth are not easy to be replaced after wear, so they must be returned to the factory for overhaul and cannot be completed on site.The traditional toothed plate structure is mainly connected by high-strength bolt and toothed seat, with small bearing capacity.And the tooth roller crusher for open pit mine needs high reliability and strong replaceable, so it is necessary to redesign the tooth plate connection structure to ensure the stable operation of the equipment.
3 tooth plate material and low temperature resistance measures
Broken tooth plate is the key easy to wear parts on the crusher, the choice of its material is very important.The tooth plate is required not only to have strong hardness, toughness, impact resistance and wear resistance, but also to take into account the subsequent machinability and weldability.At present, the commonly used wear-resistant materials are high manganese steel, low alloy tempered steel surfacing and medium carbon bainite wear-resistant steel.
High manganese steel is the most common wear-resisting material.However, when the high manganese steel parts in the process of using the repeated strong shock and deformation of the material, the surface of austenitic organization change, produce martensite structure, make the parts surface hardness increase sharply, up to more than 54 HRC, abrasion resistance increased significantly, and the center remained toughness state, thus forming a good strong toughness, it is one of the important characteristics of high manganese steel.But the tooth roll crusher's effect on the material is mainly shear and stretch, and there is no great impact and extrusion process, so the strength and hardness of high manganese steel can not be improved, so the tooth roll crusher should not use high manganese steel to make tooth plate.
In order to improve the wear resistance of roller teeth, low alloy tempered steel is often used to surfacing hard wear resistant materials.Generally, 40 Cr is used to process the broken teeth, which are tempered and tempered to improve the comprehensive mechanical properties of the broken teeth. The wear-resistant electrode is surfacing on the surface of the tooth head, thus improving the service life of the roller teeth.But because tooth head surface has only a few mm thick wear-resisting layer, this needs to be surmounted often in the use process repair, worker maintenance quantity is large, the efficiency is low.At present, it is mostly used for crushing soft materials such as refined coal, not suitable for the crushing of frozen blocks in open-pit mines.
With the transformation and upgrading of coal industry, it is an inevitable trend to develop coal chemical industry vigorously.In the field of coal chemical industry, the requirement of coal particle size is strict, which puts forward higher requirements for crushing equipment.By optimizing the structure and material of toothed roller, and adopting low-temperature resistance measures to the drive system, the new type of toothed roller crusher completes the crushing operation of open-pit coal mine, which has high block rate, small maintenance, obvious technical advantages and broad application and promotion prospects.