Removing the rollers: air-cushion conveyors glide into the spotlight  | Bruks Siwertell
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Bruks Siwertell air-cusihon conveyors

Removing the rollers: air-cushion conveyors glide into the spotlight 

27 Nov 2020

Belt conveyors use some of the most trusted and widely applied technology throughout the industrial world. When only very high-capacity belt conveyors will do, we have one of the most comprehensive ranges on the market. But imagine the advantages of removing the rollers; no seized idler-can fires, significantly reduced maintenance requirements, no material degradation from a bumpy ride, to name but a few. 

Bruks Siwertell has rewritten the belt conveyor blueprint to offer alternatives to tradition, low-friction, air-cushion conveyors, which eliminate rollers, deliver huge benefits in terms of operational and maintenance costs, and offer high-capacity conveying with no material degradation and minimal equipment wear.

Explaining the advantages of Bruks Siwertell’s flagship conveyor products, the Tubulator™ and The Belt Conveyor™, are its Vice President of Conveyor Technology, Zack Hood, and Global Sales Manager, Magnus Rundqwist. 


Bruks Siwertell air-cushion conveyor


High, steep material conveying  

With roughly 620 installations worldwide, the Tubulator is an air-supported belt conveyor, built as a closed system of steel tubes. Inside the tube, a rubber belt runs at high speed on top of an air cushion created by a series of in-line fans.

“The Tubulator offers a significant reduction in material agitation and degradation as a direct result of eliminating idler sag,” highlights Rundqwist. “This causes a bumpy ride for material, which can lead to roll back at greater inclines. As a consequence of eliminating idler sag, Tubulators can reach angles that would not be possible using traditional idler conveyors.” 

Rundqwist says the system also has a number of benefits for industries handling low-density materials, such as those for wood-processing plants, sawmills, paper mills and pellet production. 

“The Tubulator can very effectively handle almost any low-density material, whether its cement, shredded waste, grain, sugar or coal. Because it uses a cushion of air instead of idlers, there is no product degradation. Fragile materials are transported more easily and gently, creating less dust in the process,” he notes. “If any dust is generated, Tubulator conveyors are totally enclosed so emissions do not become an environmental or safety hazard; a key benefit for ports handling potentially explosive dusts.”

Tubulator systems are sectioned into 12m-long pipes, designed to fit into a 40ft standard shipping container. Because of their structural integrity and significantly reduced weight, they require fewer supports and are easier to install over existing equipment when compared with traditional conveyor frames. Tubulator conveyors are self-supporting up to 25m, and have a free-span of up to 80m when using cable towers, or up to 30m between standard supports.


Combining commercial advantages

So where does The Belt Conveyor deliver its commercial advantages? “The Tubulator is a niche product, which is absolutely ideal for certain applications,” highlights Rundqwist. 

“But for some time, customers had been asking for an air-supported conveyor that could carry a wider variety of materials and incorporate features of both the Tubulator and conventional conveyor design,” Hood continues. “This is why we embarked on a new development program and introduced The Belt Conveyor. It offers greater flexibility and can handle higher-density materials using standard belts and standard parts, which reduces costs.”

The Belt Conveyor combines the Tubulator’s air-cushion technology with a standard belt conveyor, but instead of using a pipe enclosure, it uses a formed pan to support the belt. A fully flanged cover makes it dust tight, protecting the environment and eliminating any material losses through spillage. 


Same shape, different advantages

The shape of the pan mimics the geometry of a 35-degree idler conveyor, but without the rollers, therefore it still meets the industry-standard calculations for the USA’s Conveyors Equipment Manufacturers Association (CEMA). Third-party components, like weigh-scales, metal detectors, magnets and material sensor areas, can all be incorporated into the design. 

Like the Tubulator, The Belt Conveyor benefits from a modular design that can easily be shipped and constructed. Each 3m section of the belt has access to a common header of pressurized air, and under the carry-side pan is a 3m pressurized air enclosure system, otherwise known as a plenum. Air pressure sensors and flow meters along the length of the belt ensure the optimum amount of air is delivered for the weight of the given cargo, reducing running costs. 

“Customers are already benefitting from The Belt Conveyor’s cost and material-handling advantages at several debut installations across the Americas,” concludes Hood. 

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