The 6 most common faults of circular vibrating screen
Screens on circular vibratory screeners can fail for a number of reasons, but the five most common are screen fatigue, improper installation, corrosion, shock, and abrasion. Understanding these common causes of screen failure will enable users to avoid costly downtime by proactively inspecting, maintaining, and replacing screens before they fail.
Blockage of the rotary vibrating screen
Reasonable adjustment of the screen tension is an effective method to reduce the blocking of the screen. The reasonable tension causes the screen and the supporting beam to generate a slight secondary vibration, thereby effectively reducing the occurrence of blocking. The specific method is: The tensioning hook is made into a constant force tensioning mechanism, that is, a spring is added to the tensioning bolt.
When the rotary vibrating screen is in normal operation, due to various characteristics of the material, different shapes will cause various forms of screen hole blockage.
The main reasons for the blockage are as follows:
- Contains a large number of particles close to the separation point;
- The moisture content of the material is high;
- Spherical particles or materials with multiple contact points to sieve holes;
- Static electricity will occur;
- Materials with fibrous materials;
- There are more flake particles;
- The braided screen wire is thick;
- For thicker screens such as rubber screens, the hole shape design is unreasonable, and the upper and lower parts are not large, so the particles are stuck. Because of the material that needs to be screened
Particles are mostly irregular and, therefore, the causes of clogging are varied.
How to solve it?
In order to effectively prevent the blockage of the vibrating screen mesh, measures should be taken for the above-mentioned reasons for the blockage of the screen holes:
- When the particle size of the material is fine, the mud content is large, and the screening particle size is small, the water will play a decisive role in the clogging of the screen.
- When the moisture in the material is greater than 5%, if the material is dried unconditionally, the screen surface and screen hole should be selected in a targeted manner.
- When the moisture content is greater than 8%, wet screening should be used.
- For materials with more flake particles, it is necessary to change the material crushing method and the particle size matching of different crushing methods.
The best visual indication of screen fatigue prior to failure is a floppy screen. When examining a screen post-failure, look for rounded wire ends with a dark color, which is characteristic of a screen that was damaged because of fatigue.
The best defense against screen failure due to fatigue is a properly tensioned screen, so correct screen installation is critical. Be sure to tighten the screen ring clamps. Loose clamp rings can cause screen rotation, which results in the screen losing tension, flexing during vibration, and ultimately failing. If you find that standard clamp rings are cumbersome or if you need to carry out frequent screen changes, quick-disconnect models are available.
Be sure to draw tension to the center post. This is especially important for fine mesh screens. Screens must be properly tensioned to function correctly.
Fatigue-based screen breakage can also stem from wear caused by anti-blinding devices. The plastic rings that are commonly used to prevent blinding can experience jamming during the screener’s continuous multi-plane inertial vibration. This can cause the mesh face of the screen to repeatedly vibrate over the ring until flexing leading to breakage. To spot this type of failure, look for a circular imprint on the underside of the screen.
A rubber wiper mechanism is another device designed to prevent blinding caused by resinous or fatty materials. However, the wipers can also cause screen failure if not properly installed, used, and monitored. When properly functioning, the wipers will continually sweep across the top of the screen to maximize throughput. When installed incorrectly, the wipers may jump and bounce on the screen, causing flexing and leading to fatigue and breakage if not caught in time.
Another cause of screen fatigue is the accumulation of material moving around the periphery of the screen. Commonly referred to as rope, these heavy accumulations can constantly pound and wear down the screen until it fails.