Belt Conveyor Technology
US Cement Manufacturer takes Control of Fugutive Material
Conveyor System Components
Work began on all four conveyors by disconnecting the material inlet chutes from the existing skirtboard system and removing the worn rubber skirt seals, clamps, supports, skirtboard chute walls and tail boxes. Existing idlers were also removed to allow mounting of new belt support systems and troughing roll assemblies.
On each conveyor, three Martin Trac-Mount Idlers were installed, spaced to deliver optimum belt support. The unique idler design delivers proper belt carriage, while stabilising the belt line to improve sealing. Its slim profile requires only 8 in (203 mm) of space for 6 in (152 mm) idlers, and the slide-in / slide-out frames allow service without the need to raise the belt or remove adjacent idlers.
With new idlers and troughing roll assemblies in place, each transfer point received one new impact cradle and two belt support cradles. Installed under the loading zone, Martin Impact Cradles absorb the force of falling material in a transfer point and stabilise the belt line to help prevent the escape of dust and fines. Rugged impact bars are composed of a top layer of low-friction, ultra-high molecular weight (UHMW) polymer and a lower layer of energy-absorbing styrene butadiene rubber (SBR).
Working in conjunction with the impact cradles are a pair of Martin Slider Cradles on each conveyor. Installed under the skirtboard of the transfer point, these cradles support the edges of the belt specifically to eliminate sagging. With the proper support in place, pinch points that can trap material and gouge the belts are eliminated, improving both sealing efficiency and belt life. When the top eventually wears out, the bars can simply be flipped over to provide a second wear surface.
Sixteen foot sections of skirt board were installed on each transfer point, with new side / center supports and covers. The new skirt board is 7 in (17.8 cm) high on two of the conveyors, and 12 in (30.5 cm) high on the other two. Each system also included internal skirt board wear liners and a new tail box assembly with sealing components.
To deliver positive containment of fugitive dust, each transfer point was outfitted with Martin Apronseal Skirting, a dual design with two sealing surfaces. A primary seal is clamped to the steel skirt board to keep lumps on the belt, and a secondary seal or “outrigger” strip captures any fines or dust particles that may pass beneath the primary seal. The secondary seal lies gently on the belt and self-adjusts to maintain consistent strip-to-belt pressure, despite high-speed material movement and fluctuations in the belt’s line of travel.
Each conveyor was then fitted with a Martin Tracker for the return side, installed approximately 10 feet (3 meters) ahead of the tail pulley. By providing immediate and continuous precision adjustment of the belts, the Tracker helps reduce edge damage, prevent spillage and extend belt life.
Finally, each belt received one Martin QC1 Cleaner HD as a primary cleaner and one Martin SQC2S Cleaner. The QC #1 features a special polyurethane blend and tungsten carbide tip to deliver service life 2 to 3 times longer than conventional urethane blades (According to Martin Engineering). Designed to provide excellent cleaning performance immediately, avoiding any break-in period, the assembly maintains consistent tension without frequent adjustment.
The entire upgrade operation was completed in just 11 days during the scheduled outage, with crews working 12-hour days to accommodate the planned shutdown. While specific cost savings are difficult to quantify, Denoski said the difference is easily observed. “The production team responsible for that area has had nothing but positive feedback about the upgrades,” he commented. “We’re not losing product to spillage and dust, so that material can be sold instead of cleaned up off the floor. The manpower formerly spent on cleanup can now be directed to core business activities.
“Our experience with Martin Engineering has been very positive,” Denoski concluded. “The company’s greatest strengths are its knowledge of bulk material handling problems and the best solutions for addressing them. And the no-excuses guarantee gives us the confidence of knowing that it will stand behind its products.”