Freezing temperatures can create serious operational challenges for aggregate wash plants. Frozen screws, stalled conveyors, iced-over pulleys, and damaged gearboxes often lead to unplanned downtime and costly repairs.
With proper planning and cold-weather operating practices, producers can reduce freeze-related downtime, protect equipment, and maintain productivity during winter conditions.
Common Mistakes
According to Superior's John Bennington, one of the most common errors is repeatedly hitting the start button when screws won’t turn over. Operators are often under pressure to keep material flowing, and if the screw isn’t turning, production stops. Their instinct is to “reset” by hitting start, hoping that the screw will clear itself. They may not fully grasp that ice can physically lock the screw.
They assume it’s just an electrical trip or overload that can be reset.
Repeatedly hitting the start button can cause motor damage and gearbox stress or can damage rubber or urethane shoes by causing them to rip.
Importantly, if ice suddenly breaks free, the screw can lurch violently, risking injury. Instead of clearing ice, repeated starts increase mechanical strain, damage components, and extend downtime.
Another common mistake is draining screws to remove water, thinking it prevents freezing.
"You're often better off having some ice just on the surface because that's easier to break up," says Bennington. "When ice forms down where the shoe and tub are, it acts like glue and can stall equipment.”
Also, operators often drain large vessels like classifying tanks, as they assume that’s the safe thing to do for the short term. But draining can lead to frozen valves and longer startup times.
Keeping water moving is one of the most effective ways to prevent freezing in wash plants. Bennington stresses that running the screw continuously overnight can prevent freezing, especially if temperatures stay above 20 degrees.
When components do freeze, gentle thawing is essential.
"If you apply warm water on them, you can usually break any ice loose and let it go," advises Bennington, highlighting the importance of using warm—not hot—process water to free frozen components without damage.
Bennington also notes that the real bottleneck in winter isn’t the screws or classifying tanks – but rather the head pulleys and conveyors. These smaller surface areas freeze more easily, often requiring “warming methods” to keep belts from freezing to pulleys.
To avoid conveyor head pulley freeze-ups in cold weather, operators should consider chemical deicers or preventive spray systems that stop ice from forming on belts and pulleys. These solutions reduce downtime, safety risks, and costly manual interventions.
Cold weather washing requires a blend of practical knowledge, patience, and strategic planning. By keeping water moving, avoiding common mistakes, and understanding the real bottlenecks, you can maintain productivity, protect your equipment, and mark yourself safe from cold-weather washing hazards.