Scalper media options

There are many media options that can be customized for any application. In the past, perforated steel panels or grizzly bar decks were the only choices. They are still viable choices, depending on the application, but there is new media that will also perform well.

Perforated plate decks are available in abrasion resistant (AR) steel or mild steel and are available with a wide range of openings typically from 1-1/2 to 5 inches. The deck openings are usually available in square or round holes and can be placed in a staggered layout to improve screening. Perforated plates are available with skid bars to help prevent plugging and to help reduce wear on the plate.

Grizzly bar decks are often used to increase screening capacity when exact sizing is not required.  The grizzly bars are typically available in 4- to 6-foot-long sections and, depending on the length of the scalper, there may be multiple grizzly sections with a step between each one. The grizzly bars can be set up with a wide range of spacing from 2-1/2 to 8 inches with standard bars. Special taller grizzly bars are required for larger openings.

Today, a good alternative media are rubber panels. These systems offer excellent wear characteristics and are available in a wide range of openings with molded skid bars. These panels can make accurate separations and reduce noise levels.

There are a number of media options available for the other decks. Urethane panels, non-blinding rubber, or wire cloth may be used on the lower decks to size other products on the scalper screen.

Scalper body features

The scalper typically handles large feed sizes or higher tonnage rates – or both. Therefore, the scalper body has heavier duty features. In most cases, the side plates will be thicker and include more reinforcements. It has been found that a huck-bolted design is superior to a heavily welded design or a design using traditional bolts. The liberal use of welding increases the opportunity for cracking, and traditional bolts tend to loosen on vibrating units.

The scalper screen deck frame needs to be a heavier duty design in order to carry higher tonnage rates and to accept impact from larger feed material. The media used on scalper screens also weighs more and this requires larger deck cross members. It’s a good idea to use cross member wear liners to prevent premature frame failure.

A scalper typically has extra side-plate height above the top deck to contain the higher tonnage rate and large feed size. The top-deck side plate is typically lined with AR steel or rubber. The space between the lower decks may need to be increased as well, depending on the tonnage rate.