Located just outside of Saskatoon, SK, Cargill’s Clavet Crush Plant is one of the largest Canola processing plants in North America. Cargill Canada is the sole distributor of zero trans fat oil to the McDonald’s Canada Corp., which means that each and every day, its facilities process a massive amount of canola and deal with a massive amount of by-product.
When they faced an issue with conveying efficiency, they turned to DuroVac for engineering expertise.
The high-volume, low-efficiency problem
Cargill unloaded 4,500 tons of seed per day, which would then be used to make approximately 2,000 tons of oil. Their problem? They brought in cargo by railcar and were unable to efficiently process the canola seeds, convey the flake by-product, or clean out the 60–70 railcars and prep them for re-use.
For this unwieldy cleaning process, they relied on brooms, shovels and compressed air to get the job done. Something needed to change.
Faster, safer railcar cleaning
That’s when Cargill decided to reach out to DuroVac’s experts, who had helped the company in the past with industrial vacuum systems in its loadout and flake processing areas. They trusted DuroVac as a reliable risk mitigation partner with industry-leading expertise in combustible dust and NFPA compliance.
The vacuum solution would have to be an efficient and completely NFPA compliant vacuum-conveyance system. It also required storing waste inside Cargill’s custom 6-cubic-yard bins, so DuroVac suggested the fully configurable Core Series central vacuum system.
To accommodate the special waste bins, DuroVac also supplied a custom-designed structural steel frame to help safely discharge material for repurposing or disposal.
The vacuum solution cleans out railcars quickly and efficiently thanks to DuroVac’s three-stage filtration, which handles airborne dust with an engineering-controlled system that combines power and filtration. For Cargill, that means better flake by-product collection and conveyance. The central vac helps Cargill convey 5–10 tons of combustible material per hour safely and compliantly into the plant for repurposing.
NFPA safety considerations
In an industry dealing with dust particle by-products, every effort needs to be taken to reduce the risk of combustion. Any industry leader will tell you there are three key elements that contribute to a combustion event:
While it is impossible to remove air and combustible dust from the equation, it was possible for DuroVac to implement a solution that grounded the static charge to prevent explosions, as well as a system of isolation valves and combustion mitigation equipment to diffuse any combustion events.
Explosion reduction through grounding
DuroVac understood that grounding metallic equipment and valve coatings to reduce friction were two key ways to prevent static buildup inside the vacuum unit and thus prevent ignition.
As dust particles are gathered and conveyed, they build up a static charge, and the entire structure of the central vac must work to prevent a discharge of built-up kinetic energy.
By grounding all of its metallic equipment, DuroVac’s central vac systems ensure any accumulated electrostatic charge is safely transferred to the ground without incident.
Explosion mitigation through rotary airlock discharge valves
While DuroVac’s central vacuum units can prevent most particle explosions, there is no way to completely prevent incidents from occurring.
In the food processing industry, where combustible dust is a naturally occurring reality, there is always an inevitable build up toward a discharge, especially when a system conveys as much as 5–10 tons per hour.
Because an occasional flame front occurrence is inevitable, DuroVac’s line of central vacuum systems guide and control how and where it will discharge.
The discharge valves built into DuroVac’s rotary airlocks keep the vacuum system running smoothly and help discharge potential explosions before they become dangerous. The rotary airlock is tight enough to prevent combustion 99.9% of the time, but probability is still probability, and these vacuum systems are always prepared. That’s why DuroVac uses rotary airlock inlet isolation valves supplied by ACS Valves, which act as flame front mitigation devices.
Because a flame front will naturally seek a way out of the system, the vent attenuates the energy out of the flame front and vents it harmlessly out of the system through an explosion vent or flameless vent fitted over the main discharge orifice. This discharges the flame front without it ever actually catching fire, exploding or posing a threat.
This is what made the Core Series central vacuum a two-fold solution. While designed to prevent ignition and combustion, in the event of such an ignition, the flame front is prevented from building and propagating — in this case, being fired back into the railcar or the processing plant and creating an explosion.
On the right track
Cargill needed an efficient and elegant solution for their cleaning and conveying problem, and DuroVac delivered with the Core Series central industrial, which continues to provide incredible power while mitigating the chance of combustible dust explosions.
DuroVac takes plant and worker safety seriously and understands the nuances of NFPA 652 standards. If you operate a facility in food processing, pharma, or manufacturing and you routinely handle, process, or generate combustible dust, invest in modular industrial vacuuming solutions that come pre-wired and factory-tested. You’ll save your company thousands in installation costs and maximize safety and compliance.
This case study originally appeared on Feed & Grain