Key Considerations in Transfer Chute Design
A well-designed and constructed transfer chute can significantly reduce airborne dust by minimizing induced air movement. The skirtboard sections should be sufficiently large to create a plenum that calms air currents and reduces positive pressures that might carry airborne particles out of the enclosure.
The enclosure should be spacious enough to slow down air currents, allowing airborne particles to settle back into the load before the conveyor exits the enclosure.
Chute Structure
Transfer chutes are typically made from mild steel or stainless steel plates, chosen based on the conveyed material and facility conditions.
The selection of plate thickness depends on the material's characteristics and volume moving through the chute, structural strength requirements, and wear margin if the chute lacks a replaceable liner system. Local codes govern chute structural design, requiring designers to consider all potential loads such as the chute's weight, accumulations of fugitive materials, snow, ice, the weight of bulk materials, and wind loads. Sturdy work platforms around the chute are necessary for maintenance activities. 
Transfer chutes should be fabricated in sections convenient for transport and on-site assembly. For retrofit systems, chute sections must fit through available openings to reach the construction site.
Care must be taken during chute construction to avoid imperfections that could disrupt material flow, undermining the carefully engineered design. Variations of ±3 millimeters (1/8 in.) may cause issues when aligning wear liners or aligning the chute with the belt. Investing time in precise chute installation pays off through enhanced efficiency, simplified maintenance, and reduced fugitive material.
Air cannons safely, efficiently, and effectively help maintain proper material flow.
Despite best intentions and practices of transfer chute designers, material accumulation can occur in transfer chutes, especially with moisture-laden materials that may freeze during winter. Continuous operation can compact material onto chute walls, leading to blockages. When designing chutes, it's prudent to plan for future flow-aid devices like vibrators or air cannons.
Chute Access
Enclosed transfer chutes require openings for visual inspection and doors for worker access, with clear paths for workers to reach these points. Inspection openings, like hinged access doors, should be away from material flow but accessible for personnel to monitor movement and inspect wear.
Properly placed access doors allow observation of material flow within transfer chutes.
Screens or guards protect workers from pinch points and rolling components. Corrosion-resistant covers or doors should seal tightly to prevent dust leakage. Safety barriers prevent material escape and keep workers clear of the material path.
Often overlooked is the need for access to replace liners or maintain belt cleaners within transfer chutes.
Considering future service needs is crucial for smaller chutes where personnel access is limited. Fabricating chutes in sections facilitates easier disassembly for maintenance purposes.