Home > News > Company news
Jun. 20, 2020
At present, the main production processes of sand making are wet water washing and dry sand making. The former has been widely used in the early development of machine-made sand, with problems such as large water consumption, serious water pollution, and stone powder loss. With the application of construction sand making equipment, dry production has gradually become a more popular sand making market. Craftsmanship.
Traditional dry sand making equipment
The traditional dry sand making processes include hammer crusher for mining, impact crushing mechanism sand, cone crushing mechanism sand, and sand making techniques used in combination with the above crushers, but all of them have high powder content and grain Defects such as poor shape, unreasonable gradation, low yield, and large equipment wear.
At present, domestic sand-making enterprises mainly use the new dry sand-making process, including three types of double-shaft hammer crushing mechanism sand technology, vertical shaft crushing mechanism sand technology, and roller crushing mechanism sand technology.
1. Double shaft hammer crushing mechanism sand
The equipment is mainly composed of machine body, crushing plate, upper rotor, lower rotor, pendulum, rotating drive device, sieve plate, etc.
During the operation of the machine, the two rotors run relatively. The material entering the crushing chamber is first crushed by the hammer head on the first rotor and hits the second rotor after gaining a certain kinetic energy. Because the second rotor and the material fly The direction is coming in the opposite direction. At this time, the impact speed of the second rotor on the material is equal to the superposition of 2 speeds. The material is broken through so many cycles and then discharged through the gap of the grate.
(1) The relative operation of the two rotors drives the materials in the crushing chamber to collide with each other, and the materials repeatedly collide to form the self-shredding of the stone in the crushing chamber, which greatly reduces the consumption of the hammer head and wear-resistant parts.
(2) The materials in the crushing chamber are thrown by the two rotors along the tangential direction, resulting in repeated high-speed collisions with each other, so the crushing ratio is large, the output is high, and the finished product rate is high.
(3) At the same time, due to the large output and the simple structure of the equipment, the power consumption of the machine-made sand products is low, and the operating cost is low.
(1) Because the process only adjusts the particle size, particle gradation and fineness modulus of the product by adjusting the gap of the grate, the grate needs to be replaced during the adjustment, which takes a long time.
(2) The adjustment range of gradation and fineness modulus is limited only by replacing the grate bars, and the controllability of product quality is not high. Generally, only type III sand can be produced, so there are not many mechanism sand manufacturers using this process.
2. Impact crushing sand making machine
The impact crusher, vibrating screen, dust removal module, conveying module and other parts make the complete technical equipment for sand making move towards green, harmonious, intelligent and service-oriented. The vertical shaft shaping sand making system makes the crushing host have multiple effects of "crushing, shaping, sand making, grading" to achieve the best crushing particle shape, and is equipped with vibratory screening and offline dust cleaning pulse dust collection method for centralized dust collection and dust collection The final aggregate and finished sand produced are of high quality and can achieve clean production.
(1) High crushing efficiency, with the function of fine crushing and coarse grinding. The ability to crush the material is strong, and it is little affected by the moisture content of the material. The moisture content of the feed material can reach 8%.
(2) The product has excellent grain shape and extremely low content of needle flakes. It is suitable for aggregate shaping, artificial sand making and high-grade highway aggregate production, and can be used to produce Class I sand.
(3) If it is designed for sand-making buildings, it will occupy a small area.
The structure is relatively complex, and generally needs to be used together with the vibrating screen, bucket elevator and system fan. Due to the large number of equipment, the system has high power consumption and high operating costs.
3. Sand crushing mechanism
The counter-roller crushing sand making machine is a sand-making device developed on the basis of the counter-roller crushing machine. By crushing the crushed material into the two rollers through the feeding port for squeezing and crushing, the finished material naturally falls. In case of excessively hard or unbreakable objects, its rollers can be automatically retracted by the action of hydraulic cylinders or springs, so that the gap between the rollers increases, and excessively hard or unbreakable objects fall, thus protecting the machine from damage. The two rollers rotating towards each other have a certain gap, and changing the gap can control the product particle size, particle shape and fineness modulus.
The two-roller crushing sand machine uses a pair of oppositely rotating round rollers or special-shaped rollers for crushing, and the four-roller crushing sand machine uses two pairs of oppositely rotating round rollers or special-shaped rollers for crushing.
(1) The equipment has a simple structure and less over-crushing. The tooth shape, size and arrangement on the roller surface can be changed according to the nature of the material, and can be used for medium and fine crushing of medium-hard and soft ores.
(2) The yield rate is high, and the yield rate after shaping and crushing is almost 100%. Safe and stable operation, reduce over crushing and loss, and low production cost.
(3) If it is a special-shaped roller, the two rollers are not equicircular, non-meshing, and non-equal speed, reducing the material jamming phenomenon of the roller crusher.
Although the particle shape and gradation distribution of the roller crushing sand making machine product is better than the hammer crushing sand making machine, it is worse than the vertical shaft crushing sand making machine, and generally can only meet the requirements of class II sand.
Sand making equipment comparison
(1) From the perspective of product quality, the impact crushing sand making machine is the best, and the best equipment in the industry can meet the requirements of class Ⅰ construction sand; the roller crusher is followed by the requirements of class Ⅱ construction sand; The two-axle hammer crusher is the worst and can only meet the requirements of Class III building sand.
(2) From the point of view of product yield, the counter-roller crusher and double-shaft hammer crusher can reach almost 100%, and the yield rate of vertical shaft crusher is related to the hardness of equipment and raw materials, which is about 60% to 85%.
(3) From the perspective of equipment complexity, investment, energy consumption and operating cost, impact crushing sand making machine is the highest, counter roller crushing machine is the second, and double shaft hammer crusher is the lowest.
(4) From the comparison of environmental protection, impact crushing sand making machine is the best.
In summary, users should consider the investment and operating costs when purchasing equipment, pay attention to whether the quality of the manufactured sand meets downstream requirements, and strive to obtain maximum output with minimal input.