Many times when one is wondering why efficiency is going down the first thing that is looked at is the crusher, this is many times not the case as he screen may be the actual culprit. Poorly performing screens can lead to problems throughout the production timetable. There are so many different aspects that these items can affect. Poor screens can lead to poor product quality, inefficient labor usage, increased equipment wear and overall increases in production costs are all problems that can be linked to poor screening.

There are many ways a poorly functioning screen can affect profitability without being obvious. One can experience up to a seventy percent loss in efficiency if a screen is blinded. This would mean that it is functioning at less than one third of its optimum capacity costing lots of money. In essence, the percentage of the screen that is blocked will lead to that percentage in profit loss annually. This can be a huge impact even at as low as five percent blockage on the screen. Consider how much money is lost when you have multiple screen decks that are all operating at less than optimal capacity. Those can be staggering numbers when it is put in perspective. However the costs are not only in the screens themselves. By having poor screening, you will lower the production levels for sure, but you will also have a lower quality product as well. Then there is the fact that you may not be able to keep up with demand because the screens are so blocked enough product cannot come through. This could lead to people buying less or even worse lost customers because you could not meet their needs. By not meeting customer needs and specifications you could be costing them money as well and this will not bode well for you as they will tell others and a domino effect will occur all because of poor screening. In other words, if you do not maintain the screens properly and give out poor product to one person, it could lead to you losing up to ten customers because of one bad project. Consider if you are running a portable crushing operation. You need to be as efficient and cost effective as possible. However, if you do not maintain and operate all of your equipment especially the screens, properly, you will see a huge loss in profit as well as highly elevated operating costs. A simple loss of five percent efficiency on a portable crushing outfit could cost a company up to an additional eight days of work because of that small issue that was faced with the screening. So, be maintenance minded and do what is necessary to keep everything running at the peak and as efficiently as possible.

Maximizing one’s screen efficiency is not as complicated as many have been lead to believe. This is because there are so many tools that are now available to be used today that will lead to a longer and better running screen that are actually quite easy to use and understand. There are many types of screening that are available for use today including rubber and cloth. However the predominant and optimal screening material to have and maintain is still Woven Wire. Here are some of the causes of poor efficiency:

• Poorly tensioned, loose screens beat themselves against the crown bars at a high frequency;
• Inconsistent crown bar heights prevent a proper arc for the screen cloth to tighten and rest;
• Having worn out, damaged, or missing clamp bars and rubber channel that allow material to wedge between the screen cloth and screen box rails;
• Too heavy an impact on the feed end of the screen from material falling too far onto the screen or large material falling onto small wire diameters, causing wear and breakage;
• Miscalibration of a screen’s eccentric throw, damaged springs or rubber mounts, or decks affect a screen’s vibration and can prevent an even flow and spread of material across the screen cloth leading to low throughput.

By doing simple visual inspections and looking thoroughly through the equipment on a daily basis, one can see all of the damage and spot any of these things that are occurring. Seeing these things and then doing something about them will lead to longer life for your screens as well as minimal profit loss.Go and check the screening that has been used for consistent issues. If there is a recurring tear, or a problem that shows up on a regular basis, then there will be a need to get the problem corrected and to dig deeper to find the root cause.

• Check tension on the wire cloth draw bolts.
• Check cloth and feed liner for repair and wear.
• Check springs for wear.
• Look at drive shaft and check for leaks and refill with grease as necessary.
• Check the drive belt and sheaves for wear.
• Check all clamping bars for corrosion and wear.
• Look at all nuts and bolts.
• Inspect and repair the support deck.
• Change your channel rubber frequently.
• Check cushion and spread of material feed.
• Inspect equipment for balance and excessive vibration.

Make sure to follow all procedures when it comes to starting and shutting down the screen system you use. Follow all regular maintenance checks and use the proper visual inspections to ensure efficiency and safety when using the equipment.