6 Reasons for the Small Amplitude and Slow Screening of Vibrating Screens

Summary: Vibrating screen is an indispensable device in crushing, which plays a role of screening and grading aggregates. Users can control the speed of screening by adjusting the amplitude of the vibrating screen. So how do we adjust the vibrating amplitude? And what caused it?...

Vibrating screen is an indispensable device in crushing, which plays a role of screening and grading aggregates. Users can control the speed of screening by adjusting the amplitude of the vibrating screen. So how do we adjust the vibrating amplitude? And what caused it?

Actually, the main reasons for small amplitude of the vibrating screen are as follows:

1、Insufficient power supply voltage

For example, a vibrating screen is designed according to 380V three-phase power, if the line is not connected as required; the voltage is insufficient, which will cause the vibrating screen to have small amplitude.

2、Too few eccentric blocks

By increasing or decreasing the number of eccentric blocks, you can control the amplitude of the vibrating screen. If you want to increase the amplitude, you can increase the number of eccentric blocks.

3、The included angle between eccentric blocks is too small

If the vibrating screen is equipped with a vibrating motor, the angle between the eccentric blocks at both ends of the motor shaft will also affect the amplitude. The smaller the angle is, the larger the exciting force becomes, and the larger the amplitude becomes. So users can adjust the amplitude by changing the angle.

4、Large feed cause large accumulation

If the stone conveyed to the screen surface exceeds its bearing capacity at one time, materials will accumulate in the screen funnel. This will increase the equipment load and affect the amplitude. If so, it is necessary to stop the machine first, reducing the material on the screen to the normal range, and then start. In addition, the particles of material are directly related to the vibration screen amplitude.

5、Unreasonable spring design

As we all know, vibrating screen is mainly composed of vibrator, screen box, supporting device, transmission device, etc. As an important part of supporting device, spring should be designed precisely. The net variable of the spring should be less than the height of the device, or it will cause small amplitude. What’s more? The net variable of the spring cannot be too large, or it will separate from the body.

6、Equipment failure

1）The motor or electrical components were damaged
First, the user should check out the motor, if it is damaged, it needs to be replaced timely. Secondly, check the electrical components in the control circuit, if it's damaged, please replace it.
2）Vibrator failure
Check the viscosity of grease in the vibrators, add appropriate grease in a timely manner, check whether the vibrators are faulty, and repair or replace them in time.

One thing to note is that in the process of adjusting the amplitude of the vibrating screen, whether it is increasing the weight of the eccentric block, adjusting the angle of the eccentric blocks, or increasing or decreasing the counterweight on the flywheel and pulley (off-axis eccentric vibration), the parameters of the vibration source (vibrator or vibration motor) must be the same; otherwise, it will cause equipment damage.