Insufficient tension of the tensioned screen
Writer： admin Time：2020-11-13 09:52 Browse：℃
Friends who have used linear vibrating screens know that insufficient tension of the vibrating screen will also have a certain impact on the production efficiency and output of the equipment. For example, the slack of the screen will easily cause secondary vibration, and the bending deformation of the screen will affect the screen hole. Effective penetration of the screen area, the depression of the screen surface causes material retention, hinders the forward movement of the material layer, and ultimately affects the productivity of the vibrating screen. The polyurethane screen manufacturer will share with you how to solve the problem of insufficient screen tension.
Consequences of insufficient tension of the linear vibrating screen:
1. The screen has large bending deformation and serious stress concentration. The relaxation of the screen is prone to secondary vibration, and the screen is damaged prematurely under the action of alternating stress, causing considerable economic losses.
2. The bending deformation of the screen affects the effective penetration area of the sieve holes, so that the materials that should have been screened cannot pass through the screen, resulting in a reduction in the screening efficiency.
3. The depression of the screen surface causes the material to stay, which hinders the forward movement of the material layer, and ultimately affects the productivity of the vibrating screen. Therefore, the tension of the screen should be increased to ensure that the screen surface is flat, which can effectively increase the service life of the screen, and also help to ensure the screening efficiency and productivity of the vibrating screen.
4. Part of the screen is concentrated for a long time, which will easily cause the screen to rupture, making the material that should not be screened pass through the screen and affect the screening effect. This is necessary to strengthen the tension of the linear vibrating screen, so that the entire screen is evenly stressed, and its service life is prolonged.
Solutions for insufficient tension of the linear vibrating screen:
1. Increasing the tension can also reduce the bending deformation of the screen, but it will increase the internal stress of the screen. Applying tension to make the screen to withstand a certain prestress is beneficial to improve the flatness of the screen, but it should be less than the safe allowable value.
2. Increasing the number of supports can reduce the bending deformation of the screen, but when the number of supports reaches a certain value, the effect of increasing the number of supports on the deformation of the screen is no longer so obvious. In addition, increasing the number of supports makes the strain on the screen more uniform and reduces stress concentration.
3. Increasing the tension and reducing the support spacing can reduce the bending deformation of the screen and improve the flatness of the screen surface.
The effect of tension on the flatness of the screen is to study the effect of tension on the flatness of the screen. The tension is set as a variable, other conditions are the same, and 3 support forms are uniformly used to compare the screens under different tensions. The deformation of the net and the magnitude of the stress. Select different values ??of tension from 1000N to 100000N, and perform simulation analysis in ANSYS to obtain the maximum deformation of the screen and the maximum equivalent stress. As the tension continues to increase, the deformation of the screen continues to decrease. The slope of the curve keeps decreasing with the tension, which shows that with the increase of the tension, the rate at which the strain of the screen decreases. That is, when the tension is increased to a certain range, continuing to increase the tension has little effect on the deformation of the screen, and no matter how high the tension is, it is impossible to make the screen surface * flat. This is the result of theoretical analysis. Consistent. In the range of 1000 to 20000N, the equivalent stress increase rate has a small change. The reason is that when the tension is small, the deformation of the screen changes greatly, and the part of the stress caused by the deformation of the screen also changes greatly. When the tension is greater than 20000N, the internal stress of the screen is mainly the tensile stress caused by the tension, while the stress caused by the deformation has little effect. Therefore, the equivalent stress and the tension are linear. This phase becomes a straight line.
A mathematical model is established for the tensioned screen, and the theoretical calculation shows that the bending deformation of the screen is related to the tension, the spacing of the supporting beams and the load.
(1) Increasing the tension and reducing the support spacing can reduce the bending deformation of the screen and improve the flatness of the screen surface.
(2) Established a finite element analysis model of the screen based on ANSYS, studied the influence of the tension and support spacing on the bending deformation of the screen, and verified the correctness of the theoretical analysis.
(3) Increasing the number of supports can reduce the bending deformation of the screen, but when the number of supports reaches a certain value, the effect of increasing the number of supports on the deformation of the screen is no longer so obvious. In addition, increasing the number of supports makes the strain on the screen more uniform and reduces stress concentration.
(4) Increasing the tension can also reduce the bending deformation of the screen, but it will increase the internal stress of the screen. Applying tension to make the screen to withstand a certain prestress is beneficial to improve the flatness of the screen, but it should be less than the safe allowable value.
