Steve Fair, Tyler engineered media manager at Haver & Boecker Niagara, shares tips for combining screen media for maximum efficiency.
With increased material demand, producers have an opportunity for big business, which is why it’s important to use the most productive tools for screening and sizing.
Rather than sticking to woven wire or polyurethane media throughout the screen deck, some operation managers find they can reduce wear, lessen screen change-outs, and increase open area by choosing strategic combinations of screen media.
Steve Fair
What’s the problem?
The first step toward selecting the best combination of screen media involves answering several questions: What material is being processed? Is the screen media reaching a suitable lifespan for the operation? What sort of challenges are occurring with the current screen media and at what phase of screening?
To answer these questions, producers should start by considering the types of materials going through the vibrating screen.
Material size, weight and abrasiveness all come into play during the screen media selection process.
For example, screening abrasive material typically requires media with higher wearability to handle the roughness, while materials with large top sizes may require more durable screens at the feed end due to the constant high impacts.
Producers should next look at the vibrating screen itself and complete a vibration analysis. They should then consider the three phases material goes through as it passes over the vibrating screen deck: layered to basic to sharp.
Producers can customise the screen deck by choosing screen media suitable for each phase and accounting for open area and wear life to maximise productivity.
A vibrating screen operator should also examine wearability to determine whether media in the three phases is reaching maximum potential.
If screen media is being changed too often, consider switching to something more durable. It’s a good idea for producers to complete a weekly inspection of screen media.
Any issues indicate there’s likely a better screen media option for at least one phase of screening, if not all three.
How to choose
Manufacturers create screen media out of several different types of materials, including polyurethane, rubber, perforated plate, and wire.
Producers should look for rubber screen media when screening material with a top size larger than 12 inches (30.5cm), or when an application requires an opening bigger than four inches (10.1cm).
Manufacturers can create rubber screens thicker than polyurethane for improved durability. The screens also dramatically reduce noise, handle high-impact applications, and resist abrasion.
Some manufacturers customise each plate’s thickness to a customer’s application and can create an opening of almost any size. To resist pegging, choose screens with tapered openings.
Many perforated plates come in different abrasion-resistance levels, so producers should be sure to choose a supplier that can match the appropriate perforated plate for the application.
Woven wire is often used to provide maximum open area at the discharge end of the screen deck. Manufacturers offer wire cloth in different thicknesses and weaves.
Self-cleaning screens excel at alleviating blinding and pegging, and typically offer the most open area. Because the wires are not woven, but rather bonded to polyurethane strips, they are free to vibrate independently for faster material stratification.
Think installation
After determining the best combination of materials, open area, and opening size and shape, producers should consider how the screen media will be installed.
All screen media options are available in tensionable sections, allowing producers to eliminate the deck conversion expenses.
This means an operator can blend polyurethane, rubber or metal plate media with woven wire cloth or self-cleaning screens for maximum screening efficiency.
Manufacturer matters
Calling a screen media expert is a fast way to assess an operation and find the most effective screen media blend for an operation’s specific needs.
In addition to offering consultations to help an operation find the best combination of screen media, some manufacturers also provide on-site training to make sure the entire team knows how to properly install it to maximise wear life.
A manufacturer should also provide ongoing support. Find a company that follows up to make sure the screen media works well once in use.
A partnership with a service company with integrity will save time and money, while the best combination of screen media will go far in helping improve profits and reduce maintenance headaches.
If unscheduled change-outs or contamination issues eat into profits, it’s time to consider a new screen media combination.
Choosing a variety of screen types, rather than just one, that’s suited to an application can increase productivity, lessen downtime and improve return on investment.
This feature appeared in the November issue of Australian Mining.