How to Maintain a Vibrating Screen

A vibrating screen is a mechanical screening machine that separates solids from liquids. Its design requires less power than traditional mechanical screens, reducing energy costs per ton of material processed.
When properly engineered and configured, these machines can provide a high capacity, low maintenance solution for all aggregate operations. Read on to learn more about their features and benefits:
Efficient Separation of Particles
The efficacy of a vibrating screen is based on its ability to separate particles into varying sizes while maintaining production efficiency. The vibration causes the material to move forward along a screen deck and allows the smaller particles to pass through the apertures of the screen, leaving the oversize material behind on the deck.
The size of the apertures on a screen affects how easily material can pass through them, and this is particularly true if the material has adhesive properties. Discrete element method (DEM) modelling of vibrating screens using non-spherical particle representations has helped to increase understanding of these effects.
It has been found that for coarse classification a high frequency and low amplitude is better, whereas for fine classification a lower frequency and large amplitude is better. Taking the particle shape into account is also beneficial as it reduces simulation time.
Reduced Maintenance
Like any piece of equipment, vibrating screens need to be maintained to ensure optimal operation. Taking a proactive approach to preventative maintenance helps reduce overall costs and downtime. This means working with a vibrating screen manufacturer to optimize inventory management, as well as selecting the best screen media for an operation.
Performing vibration analysis on a regular basis can help a producer spot abnormalities that may cause future breakdowns. This diagnostic tool can also reveal irregularities that cannot be detected visually, such as a broken spring. One gold mining operation worked with an OEM to perform a screening test on a screen that seemed healthy and found a faulty bearing. This was quickly repaired and saved the company money in downtime and repair costs.
A good preventive maintenance program will include daily, weekly and monthly inspections of a vibrating screen to ensure it continues operating properly. In addition, a proper lockout-tagout procedure must be performed before any maintenance work is conducted on the machine.
Increased Capacity
Depending on the screen size and material, proper screening conditions can be achieved. Screening capacity can be increased by increasing the frequency of vibration and adjusting the amplitude. Using the right amplitude and frequency helps prevent binding of the screen cloth. Screening capacity can also be improved by properly stratifying the feed and removing any surface moisture.
Allgaier vibrating screens feature a powerful vibration motor that generates an individually adjustable horizontal and circular tumbling motion to efficiently process bulk materials. Our screens can meet GMP and FDA requirements, making them perfect for hygienic applications.
The vibration of the mechanism imparts a fast, high-frequency movement to the entire screen surface, causing oversized particles to be transported down the screen quickly. This rapid movement creates a thin bed of under-screen product which reduces the amount of material that is trapped on the screen surface. This improves screening efficiency and increases the capacity of the machine. Screening efficiency can be further improved by adjusting the screen slope.
Efficient Dewatering
Dewatering using a vibrating screen is an effective way to drain sediment slurry. As the slurry passes through the screen panels water drains through the pore openings in the wire mesh. In addition, the linear motion imparted by the counter-rotating vibratory motors (or mechanical exciters on larger screens) accelerates the material upward and forward through the slurry to promote droplet formation.
Moreover, the design of McLanahan dewatering screens allows up to three different products to be processed simultaneously. This allows one fine stream and two coarse streams to be kept separate or blended to create specialty products. Additionally, longitudinal stringers provide full-length support for the urethane screens that eliminate troublesome product entry points at deck section interfaces.
The proper screen media for a particular application balances wear life and efficiency. Woven wire cloth offers high performance with good wear life while polyurethane provides extended life and greater screening efficiency than wire.