Success in bulk material handling depends greatly on a steady material flow with minimal stoppage for housekeeping, maintenance, and repair. When the material flow is challenged, it can impact operating efficiency while also creating safety risks.
A common source of poor material flow is material build-up causing pluggage in system components such as chutes, bins, and hoppers. Material accumulation can be a particular problem for facilities handling wet, frozen, or sticky bulk material such as sand or cement.
Compounding the issue, clearing pluggage by traditional means such as with hammers can create dents, bumps, and ridges in equipment, making it even more susceptible to future material blockage. Using pneumatic vibrators can crack system components as well.
Specific problems with material build-up might often include:
- caking ׀ Sticky material builds up on the inner wall of the chute, silo, bin, or hopper.
- ratholing ׀ Material gathers on the inner chute walls, which also restricts storage capacity. When the flow channel empties and the material flow stops, it can form a stable rathole than can collapse and block the opening.
- bridging ׀ Bulk material interlocks across the chute’s inner walls to form an arch above the outlet.
- plugging ׀ Material sticks to the inner walls, causing a complete pluggage.
Material blockage tends to interfere with production because it often develops out of view. Consequently, operators may have to climb into a system area to identify and remove the material build-up – sometimes in tight and unsafe spaces.
Combustible dust is another notable issue related to material accumulation. As material builds up, it can release increasing amounts of fugitive dust. Beyond being a hazard to breathing and vision, the airborne dust can concentrate to levels that can be ignited. This can be particularly true with materials such as metal powders, grain dusts, wood particles, and pulverized coal.
Dust explosions have occurred at a range of bulk material–handling facilities such as those that include recycling, woodworking, grain elevators, food production, and metal processing.
While material accumulation and blockage can meddle with operations, these challenges also can be controlled with proper flow aids.
How to Prevent Material Blockage and Keep Bulk Product Moving
Well-engineered load-zone components will aim to both accommodate and simplify the material flow demands that will be placed on them. Flow aids are systems or components installed to support a more stable and consistent transport of bulk material through the load zone. When properly designed and installed, they can have a major impact on recurring material-flow challenges.
The radial, pneumatic Clean Sweep system is an especially powerful flow aid. The system includes a reservoir of standard plant compressed air and rapid-release solenoid air valves with a trigger mechanism. Strategically positioned and sequenced air nozzles distribute the air in the optimal patterns for clearing material build-up according to its process conditions or material characteristics.
The flow aids can be mounted on wood, concrete, rubber, or metallic surfaces. To dislodge stuck material, the air is delivered in 360-degree blasts at 80 to 100 psi for a tenth of a second along chute and vessel surfaces at a distance of 2 to 3 feet.
Electronic controls trigger the Clean Sweep nozzles and fire them in a predetermined order. Operators can adjust the timing sequence and firing rates to be expanded (up to 45 nozzles) to suit various chute configuration changes. Personnel can program the system as needed and then leave it to operate automatically while they continue with other material handling tasks.
The system reservoir also can contain nitrogen for release in combustible environments. Air blasts can be delivered manually as well.
As material accumulations are loosened and broken up, they are carried away by gravity and other flowing material. This prevents material crusting and layering while improving material flow before pluggage can develop. By slicing material from walls instead of applying brute force, the system likewise reinforces dust control and workplace safety.
The Clean Sweep system’s distinctive design and layout further removes the need to worry about installing large compressed air tanks on chutes, bins, silos, or bunkers. Operators can install the air tank and control station remotely at ground level for convenient access.
In addition, operators can establish their own air-blast characteristics during installation by manipulating the operating pressure, valve design, tank volume, and nozzle shape. The system can be arranged in any way necessary in virtually any bulk material–handling environment, including those involving extreme temperatures.
Plus, unlike air lancing, which can result in injury and insufficient cleaning, the Clean Sweep system auto-cleans itself and does not require confined-space permits. It further contributes to plant safety by freeing workers from having to climb into containers or under unloading ports to address build-up manually.
The Clean Sweep system can be retrofitted into existing systems, which can save operators up to millions of dollars in equipment replacements and custom manufacturing. The system also is safe and effective for all industrial bulk material–handling applications, including those with ceramic-lined chutes. It can meet FDA constraints where required as well.
Benetech: Your Ally in Bulk Material Handling
While you are pursuing your operational goals, Benetech remains busy developing ways you can achieve them even more safely, efficiently, and profitably. We can help you clear a wider way in your material flow. To learn more about how the Clean Sweep system can support your daily objectives, contact us at (630) 844-1300 to speak with a specialist.
Posted in Material Flow, and Material Handling