Safe and efficient dust suppression during the conveying of grain

The installation of BLT WORLD’s ScrapeTec dust suppression systems for conveyor handling, has recently been completed at a wheat and barley storage and ship loading facility

According to the plant manager, the operation required a low-maintenance, long-lasting system to reduce the excessive dust and material spillage at the outdated tail and transfer chutes. Wheat and barley spillage on the floor is dangerous to walk on, which added to the urgency of a solution.

Since the installation of ScrapeTec’s highly-efficient dust suppression system was completed, dust and material spillage problems at the plant are significantly reduced and visibility during intake has improved. No external extraction system is needed and there is no longer the need for extensive cleaning operations and maintenance work on the conveyor belt is minimal.

“Apart from the importance of providing a safe working environment, it is also critical for our customers to preserve the quality of food products. The use of substandard or incorrect grain handling equipment results in kernel damage and deterioration of the grain and seeds,” explains Ken Mouritzen, Managing Director, BLT WORLD. “Our solution for this project comprises 10 m of AirScrape, a meter of TailScrape and 6 m of containment seal. To enhance efficiency of the system, we extended the tail box by a meter behind the drop chute and installed a tail Dustbox and Stainless Steel filter cloth. As we have reduced the air pressure, there is no longer dust or material spillage at the tail box, With this system, excessive air pressure is released through the filter cloth, while dust remains inside the box and drops back into the material flow.

“In front of the chute tunnel is a new 6 meter long, 1.2 m high, 0.6m wide Dustbox, which contains five curtains to supress excessive dust clouds. A Stainless Steel filter cloth has been installed vertically on the left and right sides of the Dustbox – not on the top, front or end. As with the Tailbox, excessive air pressure is released through the vertical Stainless Steel filter cloths, while dust remains inside the Dustbox and drops back into the material stream.

“The AirScrape and TailScrape do not touch the belt surface. With a specially designed diagonal arrangement of hardened lamellas, air is led from the outside into the middle of the belt, creating a powerful suction effect, enabling fine dust particles to remain in the conveyor section.

“This installation also required new site skirting to accommodate the AirScrape TailScrape and containment seal, as well as the extension of the existing chute tunnel and custom- made Dustboxes.”

Studies in other projects show, that even after five years after installation and with continuous use in harsh conditions, these dust suppression systems hardly show signs of wear. Operational costs are reduced because there is no need for spillage collection, regular maintenance, or replacement parts.

The BLT WORLD and ScrapeTec teams work closely with customers in many industries to solve the problems associated with dust emissions, material spillage and conveyor belt damage, that can lead to production downtime, costly repairs and even dangerous accidents.

Advanced solutions for conveyor systems are used in diverse sectors, including the handling of difficult bulk materials, like corn and feeds, cement, fertilizer, coal and minerals.

Additional information

ScrapeTec’s AirScrape and TailScrape systems prevent dust formation, reduce material spill, enable thorough belt-cleaning and minimise the risk of explosion at critical sections along the conveyor route and at transfer points.

AirScrape – efficient dust control

The contact-free AirScrape conveyor belt skirting system is an effective side seal that lies over the conveyor belt, without contact and creates negative pressure on the belt, due to its specially-designed lamella structure.

Because this system hovers freely above the conveyor belt, skirt friction and belt damage are eliminated and service life of every component of the conveyor is extended.

The AirScrape system encompasses inward facing, hardened steel diagonal blades and operates according to a new principle where it hovers 1-2 mm, on the left and right side above the conveyor belt.

These blades deflect larger particles inwards, while using the air-flow of the conveyor belt and conveyed material to create an inward suction, forcing any dust and fine particles back into the product flow. Through these diagonally fitted plates and the speed of the running belt, air is drawn from the outside inwards. As a result, neither the dust nor material can escape.

Conventional skirting is pressed against a conveyor belt to keep dust and material in the middle of the belt, but after a period, wear of the skirting and belt can be so severe, that material and dust escapes. Material spillage at transfer points needs to be removed and regular maintenance of belt skirting and transfer points is necessary.

With the AirScrape dust-free and contact-free, side-sealing system for belt conveyors, there is no skirt contact and therefore no belt wear or damage. Motor power requirements are reduced as there is no belt-skirt friction and because there is continuous skirting with no gaps, product loss is minimal.

This system is fitted using spacers, floating the blades just above the belt and is attached to the outside of the chute by utilising existing skirt clamps or a simple bolt and nut system. It is longitudinally adjustable to follow the contours of conveyor belt rollers and the belt trough angle.

TailScrape – the transfer tail skirting system

Like AirScrape, the TailScrape system works according to the Venturi concept, to prevent dust generation and material spills. The intelligent blade structure on the underside of the system ensures that negative pressure is created in the conveying area, preventing the escape of materials. Dust is kept in the material flow by air intake.

The TailScrape system, which enhances performance of the AirScrape, is available in small, medium and large designs, suitable for all belt widths, to match the AirScrape variants.

TailScrape is mounted precisely to the existing AirScrape system, so that it seals the transfer to the bend, averting dust generation and material spillage, also reducing the risk of explosion.

The TailScrape system operates without contact to the conveyor belt, which means there is no belt or skirting wear and because the load on the drive system is reduced, there is no belt friction. This system, which can be operated permanently, reduces maintenance requirements and replacement costs, also extending service life of components.

It is crucial that the correct conveyor skirting is used to offer maximum safety to workers and to ensure minimal deterioration of foods and to maintain the desired level of quality. It is also important in bulk handling to be able to cope efficiently with the challenges of moist and sticky materials.

These advanced conveyor belt systems – which meet stringent quality, safety and environmental standards – are available from BLT WORLD in Maryland, USA, from ScrapeTec in Germany and from carefully-selected suppliers throughout the world. Global distributors include Canada, Africa and the Indian Ocean Islands and ISC Ingenieria del Sur Sac in South America.