Today, I will give you a brief explanation of the configuration and usage of the screen aperture of the cleaning machine, hoping to help the users who use the cleaning machine.
Generally speaking, the vibrating screen of cleaning machine (also called screening machine, primary separator) uses punched galvanized sheet. According to the purpose of processing materials, there are 2-6 layers of structure, which can be used to remove large impurities and small impurities and classify according to the external size of seeds or grain.
Commonly used punching screens mainly include round holes and long holes. In order to fully ensure the effective utilization of screen area, there are various arrangements. The more holes in the same screen, the higher the permeability and utilization rate, but it is not absolute. The density of punching holes also depends on the thickness and strength of the screen.
Round hole screen, which mainly limits the width of crops; Long-hole screen mainly limits the thickness of crops. Please look at the three-dimensional dimensions of the crops below to help you understand the length, width and thickness of the crops.
Some crops (such as sunflower seeds, rice, etc.) may need to be screened according to their length, but the pit cleaner is used, which is another kind of equipment, so I won’t go into details here. This paper mainly talks about how the cleaner screens crops according to their width and thickness.
Taking wheat seed screening as an example, generally speaking, a vibrating screen with a three-layer screen structure is adopted, with a round hole of 5.6mm in the first layer, a long hole of 3.8mm in the second layer and a long hole of 2.0-2.4mm in the third layer. (In the above values, the round hole refers to the diameter, and the long hole refers to the width of the sieve hole). The first and second sieve sheets are used to remove large impurities in wheat, and at the same time, it is necessary to ensure that wheat can fall into the third sieve sheet smoothly. The role of the third layer of sieve is to ensure that wheat can no longer fall, and some small impurities can continue to fall smoothly.
The permeability of long-hole sieve is higher than that of round-hole sieve, such as processing soybean, which is also 11.0mm long-hole and round-hole sieve pieces. The materials leaked from long-hole sieve are obviously more than round-hole sieve pieces, and some rods can often fall down with long-hole sieve pieces, while they can be removed with round-hole sieve pieces. Therefore, for most materials, we usually choose to use long-hole screen for the bottom screen, which can let some small rods leak down, while the upper screen often chooses round holes to prevent large rods from falling into the next screen with seeds or grain.
The accuracy of sieve aperture is very important, which directly determines the purity of seed screening and the uniformity of grading, and its accuracy often reaches the level of 0.1 mm. For some cash crops or small seeds, it needs to be accurate to the level of 0.01 mm.
Post time: Feb-05-2023
