Coal dust strategy improves maintenance and safety

FLORIDA power supplier Orlando Utilities Commission has adopted a series of innovative dust containment measures on its coal handling system, helping the facility reduce potential hazards from fugitive material accumulations and significantly cut down the number of man-hours spent on clean-up.

Lou Caruana

By limiting dust and spillage from one of its primary conveyors, the energy provider has reduced airborne particles and virtually eliminated a potential source of trips and falls, while allowing critical manpower to be deployed on core business activities.

Preventing coal dust spillage also helps minimise wear on rollers and other moving components, saving on replacement part costs and labour.

Orlando Utilities Commission’s Stanton Energy Center is one of central Florida’s leading environmental stewards, meeting or exceeding all air permit limits with advanced pollution control equipment, while generating electricity to serve more than 342,000 residents.

SEC material handling supervisor Stuart Cason said the company followed a well-structured housekeeping policy with respect to its working environment, cleaning the entire coal yard and all handling equipment every day.

“Typically each day after we finish filling or bunkering the silos, the whole system is cleaned,” he said.

“That includes the yard, all the conveyors, chutes, floors, impact zones and rollers.

“In some places it’s a wet washdown, while in others we sweep. It’s seven days a week, every week of the year.”

As engineers planned the upgrades, SEC contacted Martin Engineering to review the conveyor system.

The team started by looking at the areas that could benefit most from new containment technology on the 36-inch conveyor, which travels at about 700 feet per minute.

To address the situation, Martin Engineering supplied and installed a number of upgraded components, including double apron seal skirting, which employs two wear surfaces on a single elastomer sealing strip installed along the bottom of the skirtboard in the loading zone.

When the bottom side of the sealing strip is worn, it can be inverted to deliver a second service life.

The skirtboard sealing system is installed on the sides of the loading zone to contain dust, eliminate spillage and reduce clean-up expenses.

It incorporates a primary seal clamped to the steel skirtboard to keep lumps on the belt and a secondary or “outrigger” strip to capture any fines or dust particles that might pass beneath the primary seal.

Next, Martin Engineering technicians installed an impact cradle to better absorb the force of the falling material and protect the belt and structure.

The cradle stabilises the belt’s line of travel to help prevent the escape of fugitive material.

In addition, a belt support system was added to better support the edges and eliminate sagging.

To maintain precise centring in the loading zone, a belt tracking system was also installed for immediate, precise adjustment.

Comprised of upper and lower components, the tracker works to reduce belt edge damage, prevent spillage and extend belt life.

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