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Hammer crusher, Roller crusher or VSI? Comparison of advantages and disadvantages of three types of equipment for sand making

2023-02-03 0

At present, the main production processes of machine-made sand include wet washing sand and dry sand. The former is widely used in the early stage of the development of machine-made sand, which has problems such as large water consumption, serious water pollution and stone powder loss. With the application of tower type sand making system, dry production has gradually become a popular sand making process in the market.

Traditional dry sand making equipment

The traditional dry sand production process includes hammer crusher sand, impact crusher sand, cone crusher sand and the sand production process used by the combination of the above crushers, but it has the defects of high powder content, poor particle shape, unreasonable grading, low yield, and large equipment wear.

At present, domestic sand making enterprises mainly use new dry sand making process, including three kinds of sand making process, namely, double-axle hammer crusher sand process, vertical axle crusher sand process and roller crusher sand process.

New sand making equipment

1. Hammer crusher sand

The equipment is mainly composed of machine body, crushing plate, upper rotor, lower rotor, pendulum, rotary drive device, screen plate, etc.

During the working process of the machine, the two rotors run relatively. The materials entering the crushing chamber are first smashed by the hammer on the first rotor and then hit the second rotor after gaining some kinetic energy. Since the second rotor flies in the opposite direction to the material, the hitting speed of the second rotor to the material is equal to the superposition of the two speeds. After so many times of repeated blows, the material is broken and discharged through the gap of the grate.

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Advantage:

(1) The relative operation of the two rotors drives the materials in the crushing chamber to collide with each other. The repeated collision of the materials forms the self-crushing 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 out from each other in the tangential direction by two rotors, forming repeated high-speed impact with each other, so the crushing ratio is high, the output is high, and the yield is high.

(3) At the same time, due to its large output and simple equipment structure, its unit machine-made sand product has low power consumption and low operating costs.

Disadvantages:

(1) Because this process only adjusts the particle size, particle gradation and fineness modulus of the product by adjusting the grate gap, the grate needs to be replaced during adjustment, which takes a long time.

(2) The adjustment range of grading and fineness modulus is limited by replacing the grate bar, and the product quality is not controllable. Generally, only Class III sand can be produced, so there are few machine-made sand manufacturers using this process.

2. Vertical shaft impact crusher

The vertical shaft crusher is composed of vertical shaft impact crusher, vibrating screen, dust removal module, conveying module and other parts, making the complete technical equipment for sand production develop in the direction of green, harmonious, intelligent and service. The vertical shaft shaping and sand making system makes the crushing machine have multiple effects of "crushing, shaping, sand making and grading" to achieve the best crushing particle shape, and it is equipped with vibration screening and offline dust cleaning pulse dust removal to concentrate dust removal and dust collection. The final produced finished aggregate and finished sand are of high quality and can realize clean production.

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Advantage:

(1) It has high crushing efficiency, fine crushing and coarse grinding functions. It has a strong ability to crush materials and is less affected by the moisture content of materials. The moisture content of the feed can reach 8%.

(2) The product has excellent particle shape and very low needle and flake content, which is suitable for aggregate shaping, artificial sand making and high-grade highway

Aggregate production can be used to produce Class I sand.

(3) If it is designed for sand making building, the floor area is small.

Disadvantages:

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 power consumption of the system is high and the operating cost is high.

3. Double Roller crusher

The twin-roll crusher is a sand-making device developed on the basis of the twin-roll crusher. By dropping the crushed material through the feed port into the two rollers for crushing, the finished material will fall naturally. In case of hard or unbreakable objects, the roller can automatically retreat by the action of hydraulic cylinder or spring to increase the roller gap, and the hard or unbreakable objects fall down, thus protecting the machine from damage. There is a certain gap between the two rollers rotating in opposite directions. The product size, shape and fineness modulus can be controlled by changing the gap.

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The double-roll crushing and sand-making machine uses a pair of oppositely rotating round rolls or special-shaped rolls for crushing, while the four-roll crushing and sand-making machine uses two pairs of oppositely rotating round rolls or special-shaped rolls for crushing.

advantage:

(1) The equipment has simple structure and few over-crushing phenomena. The tooth shape, size and arrangement on the roll surface can change with the material properties. It can be used for medium and fine crushing of medium hard and soft ores.

(2) High yield, nearly 100% after shaping and crushing. Safe and stable operation, reducing over-crushing and loss, and low production cost.

(3) If it is a special-shaped roll, the two rolls are not in equal circle, not in mesh, and not in equal speed operation, so as to reduce the material blocking of the roll crusher.

Disadvantages:

Although the grain shape and grading distribution of the products of the roller crusher are better than that of the hammer crusher, they are worse than that of the vertical shaft crusher, and generally can only meet the requirements of Class II sand.

Comparison of sand making process equipment

By comparing the advantages and disadvantages of the above three sand-making process equipment (see the following table):

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Note: The above equipment parameter information is based on the general situation, and the specific data is subject to the manufacturer.

(1) In terms of product quality, the vertical shaft crusher is the best, and the best equipment in the industry can meet the requirements of Class I construction sand; The roller crusher takes the second place and can meet the requirements of Class II construction sand; The double-axle hammer crusher is the worst, and can only meet the requirements of Class III construction sand.

(2) From the perspective of product yield, the roll crusher and double-shaft hammer crusher can reach almost 100%, and the yield of vertical shaft crusher is related to the hardness of equipment and raw materials, about 60%~85%.

(3) From the perspective of equipment complexity, investment, energy consumption and operating costs, the vertical shaft crusher is the highest, the roll crusher is the second, and the double-shaft hammer crusher is the lowest.

(4) In terms of environmental protection, vertical shaft crusher is the best.

To sum up, when purchasing equipment, users should consider the investment and operating costs comprehensively, pay attention to whether the quality of manufactured sand can meet the downstream requirements, and strive to obtain the maximum output with the minimum input.