In today’s episode of the Dust Safety Science podcast, George Hutchison, owner of CURA Engineering Solutions Corp. in Coldstream, British Columbia, talks about the belt wipe system for conveyor belt dust control.
George is an engineer with about 34 years of experience, mainly working with institutional and industrial manufacturing clients. He does various projects, including dust control, HVAC, and other mechanical engineering projects. Since around 2012, he has been deeply involved in dust systems and evaluations. George noticed that while many dust control systems in industrial facilities were effective, there wasn’t a solution for managing dust dispersion from conveyor belts. This inspired him to invent a solution for conveyor belt dust control.
What Are Some Dust-Related Challenges for Conveyor Belts?
George noticed the same problems with conveyor belts across different industries, whether they were handling mining aggregates, wood waste, or bulk food products. The main issue is called carry back, where material sticks to the belt and travels back to the tail pulley. As the belt passes over the return idlers, dust gets scraped off and falls, creating small piles called anthills. Conveyor belts also release a lot of dust into the air during their return path. This dust can be difficult to manage as it spreads throughout the facility, making it costly and problematic to clean up.
Another common issue George observed is that if the carry back material isn’t managed, sticky or wet substances can build up on the return idlers and pulleys. This causes problems like belt tracking issues, vibration, and other complications across various industries, including food products, mining, and wood products manufacturing.
How Are These Problems Being Addressed?
George replied that he often sees belt scrapers installed at the head end of conveyor belt lines. These scrapers typically remove about 20-30% of the dust from the belt’s surface, but about 70-80% remains. Most belt scrapers in the industry use a cam and spring system to press against the belt, generating a lot of heat and not conforming well to the belt’s surface if it has any profile. These systems wear out quickly because of the spring and cam mechanism that keeps the scraper in contact with the belt.
Other common technologies George sees include air knives and rotary brushes. Air knives are mounted close to the underside of the conveyor belt, near the head pulley, and are connected to the plant’s aspiration or dust collection system. These are only about 10-20% effective at cleaning the belt’s underside. Rotary brushes, often mounted near the head pulley, work fairly well but have moving parts that wear out and need a lot of air—5 to 8 times more than George’s device—to contain the dust cloud they create.
CURA’s belt wipe system is different. It doesn’t use a cam or spring to press the scraper against the belt. Instead, it deflects away from the belt, reducing the preload and heat in the urethane, which makes it last longer than competing products.
How Was the Belt Wipe System Developed?
Around 2012, George was evaluating a wood pellet plant’s dust control system. Their dust issues were so severe that they had to shut down midday for dust mitigation to comply with NFPA standards. While their dust control system worked well at transfer points and other dust-generating areas, the conveyor belts had no dust treatment.
As George examined the facility, he realized that the conveyor belts were the main source of airborne dust. This realization sparked his idea to invent a solution for conveyor belt dust control. It took him a few years to develop a viable solution. His initial idea evolved into a concept, which then turned into a trial device deployed at a bulk grain handling terminal.
The first deployment of the device didn’t meet George’s expectations, so he asked the grain terminal if he could take it back for improvements. Surprisingly, they refused, saying it was better than anything they had before. This was the beginning of the belt wipe’s development process.
George and his team managed to get the device back and made some improvements before redeploying it for a trial. During the trial, they fitted one conveyor belt with the belt wipe while a mirror image conveyor belt, dumping into the same bucket elevator, did not have the belt wipe. They ran dust accumulation tests on both conveyor belts, which operated for the same length of time and carried the same product.
Over about 25 days, the test showed incredible results for the modified device, achieving roughly 92 to 96% removal of fugitive dust. This side-by-side testing, with one belt fitted with the device and the control belt running the same product at the same speed, confirmed the effectiveness of the belt wipe.
Unfortunately, despite George’s efforts, the wood pellet plant’s dust issues were so severe that their regular shutdowns for dust mitigation impacted productivity, and the company eventually went out of business. However, George’s experience at the site helped him understand the conveyor belt dust control problem and develop a solution.
How Does the Belt Wipe System Work?
Many conventional belt scrapers try to scrape material off the conveyor belt by running a preload into a urethane device, similar to using a spatula as a knife against a moving belt. These devices aim to peel material off the belt as it moves over the head pulley.
The belt wipe system is different. It uses flexible urethane that deflects away from the belt’s path, so it doesn’t need as much preload as conventional scrapers. This design prevents heat buildup, making the device last much longer. While conventional belt scrapers, especially in facilities handling abrasive dust, typically last only 3 to 18 months, George’s device is expected to last about three times longer.
The device can also replace ineffective air knives in grain terminals. It can be swapped one-for-one with an air knife because it uses about the same amount of air and the same diameter pipe for a given conveyor belt width. This allows for an easy replacement with something that works better.
For a 36-inch wide belt, the device needs 570 CFM, typically requiring a 4 or 5-inch outlet, depending on the facility’s pneumatic conveying velocity. In some cases, it can work with less air if the client contacts them for an estimate. For a 48-inch wide belt, the device needs 782 CFM, usually requiring a 4, 5, or sometimes 6-inch diameter outlet, again depending on the conveying velocity. The device uses much less air compared to a rotary brush system.
George said that the belt wipe system has been deployed in wood products manufacturing and bulk grain facilities. They are currently looking at deploying it in an OSB facility and possibly a stick lumber facility. The case study information comes from the 2016 deployment at grain terminals. As more deployments happen, George plans to gather more case study information. He is also interested in deploying the device in the mining industry and collecting data from that too.
Conclusion
CURA’s innovative belt wipe system for conveyor belt dust control represents a significant advancement in addressing dust-related challenges across various industries. Successful trials, particularly in grain terminals, have demonstrated its effectiveness in removing up to 96% of fugitive dust.
As George continues to gather case study information from various deployments, including future applications in the mining industry, the belt wipe system is poised to become a standard in conveyor belt dust control. His journey from identifying a problem to developing a robust solution underscores the importance of innovation in enhancing industrial safety and efficiency.
If you would like to discuss further, leave your thoughts in the comments section below. You can also reach George Hutchison directly:
Website: https://cura-eng.ca/
LinkedIn: linkedin.com/in/george-hutchison-87900b15
Email: [email protected]
If you have questions about the contents of this or any other podcast episode, you can go to our ‘Questions from the Community’ page and submit a text message or video recording. We will then bring someone on to answer these questions in a future episode.
Resources mentioned
The resources mentioned in this episode are listed below.
Dust Safety Science
Combustible Dust Incident Database
Dust Safety Science Podcast
Questions from the Community
Companies
CURA Engineering Solutions Corp.
Thanks for Listening!
To share your thoughts:
- Leave a note in the comment section below
- Ask a question to be answered on the show
- Share this episode on LinkedIn, Twitter or Facebook
To help out the show:
- Subscribe to the podcast on iTunes
- Leave a review and rate our show in iTunes to help the podcast reach more people
Download the Episode
DSS268: Introducing the Belt Wipe System for Conveyor Belt Dust Control with George Hutchison
