Abstract: A self-supporting conveyor belt a portion of the length of which follows a helical conveying path comprising a plurality of stacked tiers. The belt includes a plurality of interconnected pivotal link members by which the belt can either collapse or extend along a side edge thereof to follow a curved path. Secured to the link members are wire-formed spacers which extend between adjacent belt tiers, the wire-formed spacers of one tier abutting and supporting an immediately overlying tier. The spacers provide the belt stack with increased lateral stability to prevent destacking while permitting air flow therethrough comparable to prior art spiral belts without spacers and supported by rails.

Abstract: A helical conveyor system in a freezing unit, wherein cold air from an evaporator (20) is fan-forced upwardly through the turns of the conveyor mesh, a primary cold air flow (26) is directed upwardly through the turns of the conveyor mesh, and a secondary flow (28) of cold air is incident on the top turn of the helix. This has the advantage that the coldest air impinges on the product while the latter is still at its warmest.