Part 1 explains how to make the right decisions BEFORE investing in a screening solution for your operation.
Maximizing the performance and efficiency of synthetic screen media is a combination of art and science. Optimal screening efficiency is the result of a carefully targeted mix of apertures and surface configurations, tailored to each application’s unique needs.
This requires careful selection of the screen media upfront, making sure to use the right form and function for the job, and then performing regular maintenance and quality control during operations.
With the right screening selection and maintenance strategies, producers can boost capacities, maximize uptime, increase product quality, and reduce per-ton costs.
We’re going to take a deeper dive into some of these strategies in this two-part series. Part 1 below explains how to make the right decisions BEFORE investing in a screening solution for your operation.
Form and Function
When selecting screen media for optimal efficiency—given the specifics of the application—there are a number of factors you must consider:
First, take stock of the entire screening circuit to help pinpoint the best media for the job, keeping in mind that precise data yields the best screen panel selection for maximum productivity.
• Is the material wet or dry?
• Is blinding or pegging an issue?
• How does weather or climate affect processing?
• How abrasive is the material?
Next, consider that the best applications for polyurethane and rubber screen media are significantly different. Polyurethane has higher abrasion and sliding resistance, and is more often used in wet applications. Rubber is typically favored in dry applications, and special compounds and design options offer excellent anti-plugging and blinding characteristics.
Both polyurethane and rubber are effective in reducing noise, and because the modular screen panels’ deck surface is customized in one-foot increments, they provide greater control in meeting product specifications.
To help with the selection process, work with a screen media supplier that offers a variety of screen panel options, surface features, and fastening configurations. Rely on the company’s expertise to specify the optimal panel types and opening sizes to meet the given gradations.
Once you determine the right screen media material, the media must be correctly matched to the parameters of the vibrating screen to ensure the circuit keeps pace with the crushing side. Review all potential product mixes to identify any potential gradation inconsistencies and plant bottlenecks, and make necessary adjustments upfront.
If costly maintenance downtime and loss of saleable product due to sand and fines buildup is a concern, anti-blinding panels are highly effective in mitigating the threat. When an operation runs all week without blinding—regardless of the rain or moisture content—it doesn't take long to get the payback from a new deck surface.
Similarly, to avoid bottlenecks in the screening circuit, you must correctly calculate the open area—the total number of “usable” openings on the screen as a percentage of open holes over the area of the entire screen panel surface. Thinner bridges create greater open area and a more efficient process, although they can potentially decrease a screen panel’s wear life. The open area of the screen deck can also be impacted by the panel support structure.
In Part 2 (published at the end of August), we’ll look at how a system of regular maintenance and quality control tasks can extend the life of your equipment and deliver the strongest return on your investment. We will also provide you with a downloadable checklist to help your audit.
Contact us for your Screen Performance Evaluation today!
We’ve put together a list of must-have safety checks for you and your employees when it comes to your screen media systems – read more today.
Safety of employees is top-of-mind for many plant managers and executives out there, and rightly so. In our industry, there is a potential for many workplace injuries, with heavy machinery and lots of moving parts. With this in mind, we’ve put together a list of must-have safety checks for you and your employees when it comes to your screen media systems. Read on to learn how more about workplace safety, as well as how to maximize the use of your screen media systems (safely, that is!).
1) Lock, Tag & TRY
If you’re performing any work on your screens, lock them out, along with their feed and discharge conveyors. It’s key to try the start button after locking out, to make sure you’ve got the right units. If you’re not sure where to lock out, there’s usually a plant diagram in the electrical room, or someone happy to show you how well they know the plant to help!
2) Keep it Quiet
Forget about wire or punch plate on your screens, this stuff operates at around 105dB! Switching to synthetic will reduce this to around 95dB. You might be thinking that’s just a reduction of 10dB, but decibels are a logarithmic scale, meaning each increase of +1db is a x10 multiplier. In brief, the difference between 105dB and 95dB is about half of what the human ear perceives. This will contribute to screen media safety with less risk of hearing loss and much better perception/awareness of what else is going on around the plant.
3) Lighten Up
Changing punch plate or wire cloth can be quite the task. It’s large, heavy and unruly to handle. If you haven’t done it before, think of moving a 4’ x 8’ section of sharp, heavy, floppy metal inches from the edge of a machine while balancing on ½” wide rails with openings below (eeek!). Unless you’re a heavy-lifting ballerina, it’s truly no fun. Consider modular media for a minute, which comes in 1x1’ and 1x2’ sections, for example. One person can change a localized area, away from fall hazards, without creating large open spaces to fall through beneath.
4) Make it Last
It’s no secret, changing screens isn’t fun, so why do it any more frequently than necessary? One reason is for screen media safety! Make sure you’re using as long-lasting screen media as possible as your throughput will allow. Place heavy duty media in your impact zones, and lighter formats in your flow path. This will even out the longest lasting options along your media screen’s surface and drastically reduce your workload, and exposure to any maintenance hazards. No matter what screen media you use, there are options for heavy duty to light duty formats to balance wear with open area / throughput. That said, synthetic media lasts 12-20x longer than wire will.
5) Keep Cool
Fire hazards are very real around screens. Gum rubber chute liners and cast-in-place media/liners (like spray bar boots and most magnetic liners) are highly susceptible to starting a fire. While all synthetics will burn when continuously exposed to flames, there are many options out there that reduce the risk of a fire and ensure screen media safety. Injection molded media will frequently allow a piece of hot steel to simply drop through for example, whereas cast-in-place media or gum rubber liners tend to spread fire rapidly. Some aggregate producers have entirely banned cast-in-place synthetics and gum rubber liners! If you’re doing hot work around synthetics, make sure your fire watch includes someone who can see below the work, and not just the workers above who are likely focused on their immediate point of work.
6) Dust It Off
Keeping the dust down is important to the safety of site staff and neighbors. Dust can easily blind up your screens. There’s a multitude of wire and synthetic choices out there to handle wet, sticky material on your screens. Using the right screen media to deal with blinding from dust suppression ensures you’re not sending staff into screens for nasty clean up jobs as a result of trying to improve their screen media safety in the first place!
7) Make It Simple
Make your screens simple and easy to deal with. This will ensure that when it is time to work on them, it’s likely to get done quicker and more accurately. Simplifying your screens with modular media also allows you to focus on higher priority tasks like plant automation, optimization, and better mine planning. Stop changing cumbersome screens and move on to something more fun entirely!
Go ahead, put these screen media safety tips into practice! In the meantime, if you want to learn more about Polydeck screens or any of our other products, contact us today!
Written by Alex Caruana, Aggregate Territory Manager for Polydeck.
Learn the most important factors that you should take into account when selecting your screening equipment.
When it comes to manufacturing screen media for aggregate, energy and industrial, and mining use, making them pretty is the easy part. The hard part is selecting the best solution to deliver the greatest functionality in order to meet the customer’s needs. There’s an art and science that lies behind designing screen panels for superior form and function. That’s because there are so many variables at play. The most effective screen media selection will include a mix of apertures and surface configurations tailored to the needs of each screening application to enhance capacity, reduce costs, and minimize downtime.
Tip #1: Get Started by Looking at the Big Picture
The most important exercise when selecting screening equipment is taking stock of the entire screening circuit. This will help determine the best materials to be used, as this evaluation impacts many factors. Polyurethane and rubber are popular screening materials, but have significant differences. Polyurethane has higher abrasion, cut, and tear resistance and is used mostly in wet applications. It can be made in a higher hardness rating, and it has better load-bearing capacity than rubber. Rubber is favored in dry applications and offers excellent anti-blinding characteristics at a lower (softer) durometer. Both polyurethane and rubber are significantly less noisy to operate than steel screen media and modular screen panels offer the greatest control in meeting product specifications because of their ability to customize the deck surface in 1-foot increments.
Tip #2: Calculate Correctly
Open area of the screen media is a common measure of screening efficiency but must be properly calculated in order to avoid bottlenecks in the screening circuit. For example, on wire cloth installations, apertures can be blocked by bucker bars, crown rubber, side clamp rails, and center hold-downs, so failing to consider these factors can throw off calculations by as much as 40%. It’s important to calculate the total number of “usable” openings on the screen by looking at the percentage of open holes versus the area of the entire screen panel surface. Also, thinner bridges allow greater open area that can remove further incidences of bottlenecking, and result in a more efficient process. However, the downside of thinner bridges can be decreased wear life of the screen panel. Remember that precise data yields smart screen panel selection for maximum productivity.
Tip #3: Consider Other Factors
The screen panel support system can also impact the open area of the screen. One that features ½” wide attachment rails like Polydeck's PIPETOP allows for maximum open area. Look at the panel support structure of the deck frame to evaluate how it might adversely affect the open area of the deck surface. Another important consideration -- weather and environmental factors like high humidity, which can lead to blinding problems. Mitigate these factors with anti-blinding screen panels, which require less attention which helps to minimize downtime for maintenance.
Tip #4 : Ask Questions
Establishing an efficient screening solution requires one to be proactive rather than reactive. Some questions to consider before choosing your screen media include:
- Is the material wet or dry?
- Is blinding or pegging an issue?
- Is noise a concern?
- How abrasive is the material?
- How might weather or climate be an issue?
Screen media suppliers with a great number of screen panel options, fastening configurations, and surface features are best positioned to answer these questions in order to provide the most effective screening solution for you.
As a leading provider of screen media solutions, Polydeck’s screen panels are created using an injection molding process to ensure accurate openings and consistent construction -- panel after panel. Don't hesitate to contact us if you have any questions!