Vibration screening machine manufacturers explain the factors affecting screening quality
The screening quality of the vibrating screen is the guarantee and prerequisite for the quality of the finished sand and gravel, so it is very important to ensure the screening quality of the vibrating screen. The following Red Star Machine will talk in detail about the factors that affect the screening quality of the screening machine.
Screening is a process of separating fine-grained materials and screening products from the mixture. If all aggregates that meet the particle size requirements can be sieved and classified, then the screening quality of this screening machine is super high. On the contrary, If a lot of aggregates smaller than the mesh size can only partially pass through the mesh for some reasons, and some of them are still on the screening machine and have not been sieved and classified, then at this time, we can say that the screening quality of the screening machine is not To the best degree.
Vibrating screening machine manufacturers explain the factors affecting the screening quality In actual screening production, what factors will affect the screening quality of the screening machine? The experts of Red Star Vibration Screener will make a simple analysis for you next.
1. The influence of moisture
The moisture content of the material greatly affects the screening rate of the screening machine, because once the moisture content of the material is, the sand and gravel aggregates are particularly easy to stick to the screen or directly bond into agglomerates, causing the screen holes to be partially blocked and being left on the screen. The sieving and classification is completed, which makes the product appear inferior, which seriously affects the sieving quality.
2, the shape of the mesh and the particle shape of the screened material
It is very important to choose the mesh shape, and different mesh shapes have different characteristics. Commonly used sieve hole shapes are divided into round, square and rectangular. The sieve holes of the punching screen are mostly round, while the woven screen has rectangular holes and square holes. Practice has proved that the effective sieve area and the chance of ore particles passing through the sieve are different depending on the shape of the sieve. The effective area of the rectangular sieve is the largest, followed by the square, and the circular sieve has the smallest effective area.
Compared with the three kinds of sieve holes, the rectangular sieve has the most advantage, because the rectangular sieve is not easy to be blocked. When the ore particles pass through the sieve, it only needs to contact with three or two sides of the sieve, and the resistance is small. When the ore particles pass through the round or square sieve holes, they need to be in contact with the four sides of the sieve hole, so that the resistance of the ore particles will be relatively large. When using a rectangular sieve, the long side of the sieve should be consistent with the direction of movement of the material.
The shape of the sieved material particles also affects the sieving quality. As far as the sieving rate is concerned, spherical and cubic particles are easier to sieve than needle-shaped particles.
3, the movement mode and amplitude of the screening
Red Star experts, through detailed data analysis and experimental research, concluded that the effects of different movement modes of the screening machine are different. The screen surface of the circular vibrating screen moves in a circular motion when it is close to the center of mass, and the two ends are elliptical motions. The farther the distance from the center of mass is, the greater the difference between the major axis and the minor axis of the ellipse.
The movement of each point on the screen surface of the circular vibrating screen is different, resulting in different vibration parameters everywhere on the screen surface, and the movement speed and direction of the material at each point on the screen surface are also different, which is conducive to the loosening of the material, and the material collides with the screen surface from different directions. The large penetration probability is more suitable for the screening of large-size materials and the classification of raw coal. The vibration of each point on the screen surface of the linear vibrating screen is the same, and the material is not easy to break up after stratification, which increases the contact time between the bottom material and the screen surface and increases the probability of screen penetration. The regular vibration of the screen surface can reduce the disturbance of particles to the water flow. It is beneficial for the water flow to carry heavy medium and fine mud through the screen. Therefore, the linear vibrating screen is suitable for the dewatering, desliming and de-intermediation of fine-grained screens and materials.
Vibration is related to screening materials. If other conditions remain unchanged, the vibrating screen's processing capacity is within the range of 40-60 tons and the amplitude is 3~4 mm, the amplitude will change with the increase in the processing capacity of the screening machine, otherwise the screen will be out. The quality of the products cannot be guaranteed. In production, the amplitude is usually 3-6 mm, and the vibration frequency is 500-1200 revolutions per minute. If it is too large, the material will not pass through the screen surface easily, and it is easy to damage the screening machine.
4. Screening size and inclination
The size and inclination of the vibrating screen will also affect the quality of aggregate screening. Under the condition of equal load, when the width of the screen surface is small and the length is large, the thickness of the material on the screen surface increases, making it difficult for the material to approach the screen surface and pass through the screen holes. On the contrary, when the width of the screen surface is large and the degree of dryness decreases, the thickness of the material layer will decrease, making the material easier to approach the screen surface. However, since the particles stay on the screen surface for a short time, the probability of particles passing through the sieve holes decreases. Therefore, the screening time and the size of the screen surface must be moderate. Generally, the width and length of the screen are 1:2~1:5. If the inclination angle of the sieving machine is too large, the moving speed of the particles along the screen surface will be too fast, which will make the produced products have a phenomenon of inferior diameter. Therefore, determining the proper inclination of the sieving machine is also very important to ensure the screening quality.