A single spark is all it takes to ignite grain dust. That’s why a major grain handler reached out to Kinder Australia to find a solution.
A major Queensland bulk terminal was faced with a predicament. Due to a high material drop at a transfer chute, excessive dust was shooting out at the front of an old, enclosed tunnel like out of a “barrel of a gun”.
The 10-metre-high drop created a high material flow pressure at the end of the chute at the drop zone of the receiving conveyor.
The facility, which currently accommodates more than 85,000 tonnes of bulk grain storage, needed to ensure this dust was contained.
Its maintenance supervisor specifically sought out a low maintenance, long lasting solution to suppress and minimise the dust and spillage at the facility’s outdated tail end transfer chutes.
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Additionally, the solution needed to be fire resistant and anti-static (FRAS) to avoid any explosion risk.
Bart Fox, field applications engineer at Kinder Australia, told ABHR the operator had previously relied on double sealing skirtings, which were quickly worn through.
“The key thing we do as field application engineers is understand the root cause of the problem,” he said.
“Rather than taking a one size fits all approach or offering a band-aid solution, we go visit the site to learn more about the problem,” he said.
“For this site, the main issue was the high pressure in the load boot, improper load support and an incorrect containment of the product.
“Knowing this, we were able to offer the right solution.”
Kinder and Conbulks worked together to modify the drop zone to divert the grain and barley to be more centrally loaded.
The site skirting was also modified to accommodate Kinder’s FRAS AirScrape, FRAS TailScrape, and FRAS K-Containment Seal.
Engineered with low friction polyurethane, the K-Containment Seal is designed to contain the bulk product and improve the effectiveness of the outer seal by reducing the high internal pressure experienced inside the chute.
Meanwhile, AirScrape system is a contactless skirting system that is suspended above the conveyor belt itself and uses air movement to prevent fine dust particles from escaping.
A diagonal arrangement of hardened lamellae leads air from the outside into the middle of the belt, creating powerful suction. The material movement, together with the moving belt support, increases the suction effect, keeping fine dust particles in the load zone of the belt.
Any coarse materials pushing outward are led back to the middle of the belt by the lamellae, which can significantly minimise spillage.
Bart said the K-Containment Seal’s proprietary polyurethane formula avoids damage to the belt and is a much gentler option than other products on the market.
“When the primary containment method is not at a high enough standard, it means the secondary containment system needs to work harder to contain spillage instead of just dust. This leads to faster wear and more dust.”
In addition, Conbulks and Kinder extended the existing chute tunnel and designed custom DustScape dustboxes.
Behind the drop chute, the tailbox was extended by one metre, with a stainless steel filter cloth. In front of the chute tunnel, a six-metre-long, 1.2-metre-high custom dustbox was installed, also including a stainless steel filter cloth. Inside the dust boxes, five dust barriers and curtains were installed to further settle the flow and suppress excessive dust clouds.
With the reduction in air pressure, dust and material was no longer forced from the tail box. Excessive air pressure gets released through the filter cloth and dust remains inside, dropping back into the material flow.
All of the Kinder equipment was supplied using specialised polyurethane that has been tested to ensure it is suitable for the task.
Bart said Kinder’s engineers work across the spectrum of bulk handling industries, including quarries, ports, mines, and concrete batching plants.
“Nearly every site is dealing with the same problems – and dust control is a big one” he said.
“That being said, even though they have the same problems, each site needs a different approach and a customised solution, which is why we have a broad range of options available.
“Kinder has a representative in almost every state. We can get on a plane and visit a site to provide technical support and find the right tool for the job.”
Following the installation of Kinder’s equipment at the Queensland bulk terminal, the site has greatly reduced the risks associated with wheat and barley spillage.
Visibility during the intake process has also drastically improved, to the point where an external extraction system is no longer necessary, providing cost savings and simplifying maintenance.
With a life expectancy of 20 years before wearing out, the dust and spillage control system offers the facility long-term reliability and effectiveness. The maintenance supervisor has even started planning similar solutions for other areas of the facility in future.