What are the three types of coal breakers
In the field of coal mining and processing, the coal breaker is a key equipment for controlling the particle size of coal materials. Depending on the differences in structural design, working principle and application scenarios, the common coal breakers are mainly divided into three types: Feeder Breakers, Rotary Breakers and Roll Crushers. Each of them undertakes different crushing tasks and is suitable for different scenarios, such as continuous feed crushing, large lump coal separation crushing and medium-fine coal crushing, collectively forming the core equipment system for material processing in the coal processing process.
Specific introduction of the three types of coal breakers
Feeder Breakers
The feeder breaker is a device that combines “feeding” and “crushing” functions. It can provide a highly reliable production method for continuous feeding and crushing of most layered and mining materials (including wet materials, dry materials, viscous materials, and mixed materials). Its configuration is flexible, and it serves as a “connection bridge” between the mining system and the material handling system, ensuring efficient and multi-point operation of both systems.
Working principle
When the drive device of the feeder is activated, the driving sprocket will drive the chain to move horizontally within the conveying box, dragging the materials forward. When the chain and the materials pass through the rotating tooth rollers in the crushing box, since large pieces of materials cannot pass through the specific gap between the tooth rollers and the base plate, they will be repeatedly impacted, compressed and stretched by the rotating tooth rollers until they are crushed into small pieces that can pass through the gap.
Core features
It can be directly fed by trucks or loaders, eliminating other types of feeding equipment and simplifying the operation process;
The crushing teeth are arranged symmetrically and at intervals, covering the entire crushing surface without any blind areas. It can not only crush hard materials but also minimize the generation of fine materials;
The replacement of wear parts is simple and convenient, reducing downtime for maintenance and lowering operating costs;
Reducing or even eliminating the need for excavation and civil engineering significantly reduces equipment costs and construction expenses;
Light in weight, small in size, flexible in layout, and easy to move, suitable for scenarios where the operation position needs to be frequently adjusted.
Rotary Breakers
Rotary Breakers is a crushing equipment centered on a “rotating cylinder”. It is mainly used for the crushing and sorting of raw coal, especially adept at handling large pieces of raw coal containing impurities (such as gangue). It is widely used in the initial processing of coal.
Structure and Working Principle
Rotary Breakers consists of a cylinder. The cylinder rotates at a relatively low speed through four ear shaft rollers; the thrust rollers installed at both ends of the base frame can prevent the cylinder from moving laterally during rotation. Its drive system usually adopts a “motor – coupling – reducer” configuration: a large driven sprocket is bolted on the processing circumference of the cylinder inlet end, and a small driving sprocket is installed on the output shaft of the reducer, which are connected through an engineering chain (the chain is placed in an oil bath chain box).
When raw coal and gangue enter the cylinder, they will be lifted to a height of approximately “11 o’clock direction” inside the cylinder, and then fall onto the screen plate on the inner wall of the cylinder. Through repeated lifting – falling actions, combined with the impact of hard gangue, the coal will be crushed and pass through the sieve plate holes to become qualified products; while the non-crushable waste materials (such as large pieces of gangue) will continue to advance in the cylinder and finally be discharged from the other end of the discharge plow with the assistance of the discharge plow.
Core Features
It has both crushing and sorting functions, which can separate gangue and other impurities from the crushed coal while crushing the coal, reducing the subsequent sorting process;
The rotating speed of the cylinder is slow, causing little wear on the materials, which can reduce the generation of fine materials and protect the quality of the coal;
The structure is sturdy, capable of withstanding the impact of large and hard materials, and has strong operational stability;
It is equipped with a dust-proof shell and replaceable dust-proof sealing components to reduce dust leakage and comply with environmental protection requirements.
Roll Crushers
Roll Crushers are one of the most widely used crushers in the mining industry. They are suitable for crushing fragile minerals such as coal, natural alkali, salt, and glass. They are particularly outstanding in scenarios where it is necessary to control the particle size of the products (such as medium and fine particle sizes) and reduce the generation of fine materials.
Working principle
The crushing force of Roll Crushers comes from the combination of “impact, shear, and compression”: After the material enters the crushing chamber, it is first impacted by the rotating rollers; then it is sheared and compressed between the rollers and the crushing plate (or another set of rollers), and finally fractures along the natural cleavage plane.
Depending on the crushing requirements, different configurations can be selected: For single-stage crushing, a single-roller or double-roller crusher can be used, completing the size reduction in one compression; if two-stage crushing is needed, a three-roller or four-roller crusher can be selected – the top roller group completes the primary crushing, and the material directly enters the bottom roller group for secondary processing, ultimately obtaining the required products.
Core features
Large processing capacity, low required clearance, low energy consumption, suitable for large-scale continuous production;
Can handle wet materials, viscous materials, and is less prone to clogging;
Products are in a cubic shape, and less fines are produced (due to crushing along the natural cleavage plane);
Design is simple, reliable, and has low maintenance requirements;
Has an “object protection function”, which can automatically adjust the gap when encountering non-crushable objects to allow them to pass, and then restore the initial setting to reduce the risk of equipment damage.
Comparison of three coal breakers
From the core function perspective
The core function of feeder breaker is continuous feeding and crushing, playing an important role in connecting the mining system and the material system; Rotary Breakers mainly function as crushing and sorting, able to separate impurities such as gangue while crushing coal; Roll Crushers focus on medium and fine particle crushing and can effectively control the product shape.
In terms of applicable materials
Feeder breaker has a wide range of applications, capable of handling various mining materials such as wet, dry, and viscous materials; Rotary Breakers are more suitable for processing large pieces of coal with gangue; Roll Crushers can be used for crushing coal, easily breakable minerals, and can handle wet and viscous materials.
Product particle size
The product particle size after feeder breaker crushing is medium, meeting the requirements for subsequent transportation; Rotary Breakers’ product particle size is also medium, determined by the sieve plate hole diameter; Roll Crushers’ product particle size is medium and fine, and can be controlled by adjusting the roller gap.
Fines production volume
All three crushers can achieve less fines production. Feeder breaker benefits from the symmetrical arrangement of the toothed rollers; Rotary Breakers reduce fines production due to the slow rotation speed of the cylinder, with softer impact; Roll Crushers are due to the material being crushed along the natural cleavage plane.
Mobility flexibility
Feeder breaker is lightweight, small in size, and has high mobility, suitable for frequently adjusting the operation position; Rotary Breakers are large cylinders and fixedly installed, with low mobility flexibility; Roll Crushers, for some small equipment, can be moved, with medium mobility flexibility.
Main advantages
Feeder breaker integrates feeding and crushing, saving equipment costs; Rotary Breakers have both crushing and sorting functions, reducing subsequent steps; Roll Crushers have good product shape, low energy consumption, and simple maintenance.
Maintenance points of three coal breakers
feeder breaker
Regularly check the tension and wear condition of the chain, and adjust or replace it in time to prevent the reduction of conveying efficiency due to loose chain;
Clean the adhered materials on the tooth rollers (especially the sticky materials), to prevent the appearance of crushing blind areas;
Regularly lubricate the bearings and sprockets of the drive device to reduce friction loss;
Check the wear degree of the crushing teeth, and symmetrically replace the severely worn teeth to ensure the uniformity of crushing.
Rotary Breakers
Regularly check the lubrication status of the ear shaft rollers and thrust rollers to prevent an increase in the rotational resistance of the cylinder due to dry friction;
Clean the blocked materials on the sieve plate (such as wet material clumps), ensuring the screening efficiency;
Check the tightness of the chain and the oil quantity of the oil bath chain box, and replenish the lubricating oil in time to prevent chain rusting;
Regularly check the fixation of the lifting plate and the discharge plow to avoid poor material transportation due to looseness.
Roll Crushers
Regularly clean the adhered materials on the roller surface to prevent uneven wear of the roller surface;
Check whether the gap between the rollers meets the crushing requirements and adjust it in time according to the product particle size;
Lubricate the roller shaft bearings to avoid overheating damage due to insufficient lubrication;
Check the sensitivity of the foreign object protection device to ensure it can act promptly when encountering hard foreign objects, protecting the equipment.
Selection method for coal breakers
When choosing a suitable coal breaker, the following core factors should be considered:
Material characteristics
If the material is wet, viscous, or requires continuous feeding (such as direct crushing at the mining site), feeder breakers should be preferred;
If the material is large pieces of coal with coal gangue, both crushing and separation need to be completed, and Rotary Breakers are the first choice;
If it is necessary to control the product to be medium and fine particle size and with regular shape (such as cubes), Roll Crushers are more suitable.
Production requirements
If “feeding + crushing” integrated operation is required to reduce the number of equipment, feeder breakers should be selected;
If the processing capacity is large and long-term fixed operation is required (such as coal washing plants in coal mines), Rotary Breakers or large Roll Crushers are more suitable;
If the crushing particle size needs to be flexibly adjusted (such as different customers have different requirements for coal particle size), Roll Crushers (with adjustable roller gap) are better.
Site conditions
If the site is small and needs frequent movement (such as temporary crushing in underground mines), feeder breakers should be selected;
If the site is spacious and can undergo fixed construction (such as ground processing plants), Rotary Breakers or Roll Crushers can be considered.
Selection suggestions for different user groups
Coal mining enterprises (underground / open-pit mining)
Priority should be given to feeder breakers. They can directly receive the feed from trucks or loaders, no additional feeding equipment is required, and they are small in size, flexible in movement, and can adapt to the complex environment of mining sites, quickly connecting the mining and material transportation systems.
Coal washing and processing plants
Rotary Breakers are recommended. Coal often contains coal gangue and other impurities, and the “crushing + separation” function of Rotary Breakers can separate impurities in advance, reducing the pressure of subsequent washing and selection, while reducing fine material production and improving coal recovery rate.
Coal processing enterprises (such as coal chemical plants, briquette production)
Roll Crushers are recommended. These enterprises have higher requirements for the uniformity and shape of coal particle size. Roll Crushers can produce cube products and have less fine material, meeting the feeding requirements of the processing section, and having low energy consumption, suitable for long-term continuous production.
Summary
Feeder Breakers, Rotary Breakers and Roll Crushers are the core equipment for coal processing, each leveraging its unique advantages such as “integration of feeding and crushing”, “synchronization of crushing and separation”, and “precise control of particle size” to meet the crushing demands throughout the entire process of coal mining, washing and processing, and further processing.
When choosing, a comprehensive judgment should be made based on the material characteristics, production requirements and site conditions: For the mining site, flexibility and continuity are emphasized, so Feeder Breakers can be selected; for the washing and selection stage, separation of impurities is the priority, so Rotary Breakers can be chosen; for the further processing stage, attention is paid to particle size and shape, so Roll Crushers can be selected. At the same time, regular maintenance can extend the equipment’s lifespan and ensure long-term stable operation.
Through reasonable selection and scientific maintenance, these three types of coal breakers can efficiently assist in the material handling of the coal industry, laying a good foundation for the subsequent production processes.
