Hopper, Tank & Chute Heaters plus Control Systems

Hotfoil-EHS specializes in electric surface heating systems. Applications include fly-ash hoppers on electrostatic precipitators, baghouses, coal and material handling systems, tanks, and pipes.

For more information, contact Hotfoil-EHS by calling 609.588.0900 or visit https://hotfoilehs.com.

Prevent Bulk Material Flash Freezing in Hoppers and Chutes

Heaters in stalled on a chute.

A phenomena know as “flash freezing” occurs when aggregate material with trace amounts of absorbed water comes into contact with very cold metal surfaces, resulting in the aggregate instantaneously freezing.  The frozen material then instantly bonds to steel chutes or hoppers (which are at sub-freezing temperatures) causing an immediate, and possibly catastrophic, block in the hopper or chute.

Once this occurs, the cure is often a jack-hammer or other type of brute force method to clear the obstruction It's common for any coal mine, quarry, cement manufacturer, mining facility, or power plant to have a sledge or jack hammer on call for just this purpose. A far better approach is to prevent  sand, cement, ores, and mined products from freezing in the first place. 

The best solution are electric FRP heating panels. FRP heating panels are waterproof, dust tight, and vibration resistant electric heater panels that mount to the exterior walls of the hoppers and chutes. 

Specially designed for use in high shock and high vibration applications, their robust construction and corrosion resistance provides long life. 

Multiple heaters on a round hopper.

Because these atmospheres are normally dusty, and occasionally ignitable,  FRP panels are available with FM approval for use in hazardous areas. Furthermore, because hoppers, ducts, and chutes come in a never-ending variety of sizes and shapes, FPR panels are easily customized to conform in shapes and size to virtually application. 

If you work in a plant or facility where bulk material absorbs ambient moisture, and the possibility of freezing exists, you should learn more about FRP heating panels and their benefits they provide in reducing downtime, and more efficient operations. 

Electric Process Heaters & Controls

Hotfoil specializes in electric surface heating systems for fly ash hoppers on electrostatic precipitators or baghouses, coal and material handling systems, tanks, pipes, etc. in all types of industry.

For more information, visit http://www.hotfoilehs.com or call 609.588.0900.

Hazardous Area Heater Control Systems for Coal Hoppers and Conveyors

Explosion proof control system.

A major hazard in coal burning utilities is the transfer and storage of coal due to the presence of highly combustible coal dust. Mitigating the risks of combustible dusts eliminate the potential for dust explosions. It is critically important that any coal handling or coal storage facility have access to experienced application engineers who understand the specific requirements when handling coal and managing coal dust.

Electric heat is very often used to prevent coal freeze-ups in hoppers and conveyors. The most common electric heaters used are are exterior mounted panel heaters with carefully calculated watt densities to keep sheath temperatures low. A less preferred solution is the use of tubular heating elements that may have higher sheath temperatures. Tubular heaters are usually clamped or stud-welded to the exterior of the coal hopper or conveyor chute.  In either case, a control system must be employed to maintain operating temperatures and to safely limit temperatures below dust ignition temperatures.  Since the presence of coal dust in the atmosphere is considered normal, the use of explosion proof housings, conduit, and wiring practices is required for these control systems.

Internal view.

Hotfoil, a New Jersey manufacturer of electric hopper and coal handling heating systems,  designs, engineers, and fabricates custom control systems specifically for these applications. 

With decades of experience in hopper, conveyor, and tank heating systems they provide their customers with a single-source, turn-key, electrical heating and control system solutions provider. All products are 100% quality tested prior to leaving the facility, and an added plus is that they provide on-site start-up assistance.

Don't Let Frozen Aggregate Clog Your Process Equipment

FRP hopper heaters

FRP chute heater

Processing lines in coal mines, quarries, cement plants, mining facilities, and power plants have a special problem in very cold weather. The coal, sand, cement, ores, or other mined products they handle can freeze and cause equipment outages. The combination of trace moisture mixed with aggregate material, plus freezing temperatures, combine for major problems with conveyors, hoppers and chutes. When the aggregate hits the cold steel surface, it instantly freezes (flash freezing). The bond between the frozen aggregate and the steel wall is virtually unbreakable, and can cause long down-times with the equipment. Maintenance people have their own, time-tested curative solutions - torches and hammers - but installing preventative measures is clearly preferable.

FRP trough heater

The FRP heating panel, a waterproof, dust tight, and vibration resistant heater is an excellent preventative solution. FRP heaters are designed to be used in the high vibration, corrosive and dirty areas where they are installed. Available with FM approval for use in hazardous areas, they provide an easily customized panel that conforms to the shape and size needed to fit any chute or hopper. Additionally, they are lightweight, can be applied to flat or curved surfaces, and are very easy to install and maintain.

FRP trough heater

For more information on chute, conveyor, hopper or pipe heating, contact the experts at Hotfoil-EHS by visiting www.hotfoilehs.com or calling 609-588-0900.

Freeze Protection for Coal Handling Systems

Coal stored outdoors on the stockpile or delivered by unit train or barges picks up moisture from rain and snow. When this wet or frozen coal is conveyed, it inevitably comes into contact with the plate steel of the various hoppers and chutes within the coal handling system. During winter, this plate steel is below freezing for extended periods.

When wet or frozen coal encounters steel at sub freezing temperatures an instantaneous bond is formed. This bond causes immediate and often catastrophic blockage of the hopper and chutes. The bond and resultant blockage is so severe that pneumatic drilling equipment and explosives are often required to free up the system.

This problem, known as FLASH FREEZING, is extremely inconvenient and very costly. Several cases are documented where utility and industrial boilers have been shut down due to blocked conveying systems.

The document below describes effective electric heating systems for coal handling freeze protection.

Freeze Protection for Coal Handling Systems from Hotfoil EHS, Inc.