What Are the Screening Methods of Linear Vibrating Screens?

Do you know what are the screening methods of linear vibrating screen? The following linear vibrating screen supplier will explain to you. In the material sieving process, the powder sample passes through a series of standard sieves with different holes and is separated into several particle classes and weighed separately. The particle size distribution expressed as a percentage by mass is called the sieve analysis method. That is sieve analysis, the purpose of which is to determine the particle size composition of the material.

Common screening methods are the following three; these three screening methods can roughly meet the user's screening requirements for different materials. The linear vibrating screen analysis method can be divided into several types of dry screening, wet screening, hand sieving, wet and dry mixing, mechanical screening, airflow screening, acoustic sieving, disc sieving, and self-organizing screening. Etc., the results of sieve analysis are often expressed in terms of frequency distribution and cumulative distribution of particle size distribution. There are many methods mentioned above, depending on the material screened by the user

1. Dry sieving method

The so-called dry sieving method, as the name implies, is to calculate the difference between the sieve margin and the bottom stock of each sieve meter and the total dry mass m0 of the sample before sieving, as the loss in the sieving process, and calculate the loss rate. A certain weight of powder sample in the sieve, with the help of mechanical vibration or manual knocking, so that the fine powder through the screen until the sieving is completed. The sieve residue of the powder sample is calculated according to the weight of the residue on the sieve and the weight of the sample. When determining the particle size distribution, the dry sieve method is generally used.

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2. Wet sieve method

A certain weight of powder specimen is put into the sieve and washed with a suitable dispersion water flow (certain water pressure) for a certain time to complete the sieving. According to the weight of the sieve residue and the weight of the specimen, the wet sieve method is used to obtain the sieve residue of the powder specimen. If the sample contains a lot of water, particle cohesion should be used wet sieve (higher accuracy than a dry sieve), especially for fine particles of materials. If mixing with water is allowed, it is better to use a wet sieve. Because the wet method can prevent the very fine particles from sticking to the sieve holes and blocking the sieve holes. In addition, the wet method is not affected by the temperature of the material and atmospheric humidity, and the wet method can also improve the operating conditions. Therefore, the wet method and the thousand-point method has been listed as the national standard method for determining the fineness of cement and raw materials.

3. Dry and wet combined sieve analysis

Dry and wet combined sieve analysis is a combination of two methods to choose the best method. When the material contains more water and mud, and the material is bonded to each other, the dry and wet combined sieve analysis method should be used, sieve analysis to obtain more accurate results... The specific method is to pour the sample into the fine hole sieve, in the basin with water over the sieve. Change the water in the basin every 1 to 2 minutes until the water in the basin is no longer cloudy. The material on the sieve is dried and weighed, and the mass of the washed fine mud is calculated according to the difference between the weighed mass and the mass of the original sample.

The above three sieving methods are simple equipment and easy to operate, but the sieving results are easily affected by the shape of the particles. The size of the particle size distribution is relatively coarse. When the lower limit of the test exceeds a certain value, the screening time will be reduced. It is easy to block the screen when it is stretched out. Therefore, the size of the material should be adjusted as much as possible when screening, so that the material will not block the screen.