A spiral conveyor having a self-stacking conveyor belt positively driven on a helical path up or down a drive drum. Stacker supports at opposite sides of the belt support the tiers above. Locking structure on the outer stacker supports interlock consecutive tiers. Drive members on the drive drum have a belt entrance segment and a positive-drive segment. The positive-drive segment has ridges that engage the inner side of the belt without slip. The entrance segment provides a smooth reduction in drum diameter without drive ridges to multiple belt tiers entering the helical path.

A spiral conveyor is described. The spiral conveyor provides an extremely open design. The open design creates and defines a very sanitary design. The combination of a cantilever frame construction (with no side frames) and the edge/side driven belting allows for superior access and cleanability. This access and cleanability are of paramount importance to the food market, where sanitation requirements are stringent to maintain food safety by preventing bacteria growth.

A thermal processing apparatus (20) includes a spiral conveyor system (22) configured into an ascending spiral stack (26). An inner mezzanine (40) is disposed within the circular interior of the stack (26) and an exterior mezzanine (42) encircles the spiral stack. The mezzanines divide the processing chamber (32) into a plurality of processing zones. A sealing system (90) seals the interior mezzanine (40) relative to the spiral stack (26). A sealing system (130) seals the outer mezzanine (42) relative to the exterior of the spiral stack, and a seal system (132) seals the outer mezzanine relative to the walls (56, 58) of the housing, thereby to limit the leakage of the processing fluid between the mezzanines and the spiral stack (26) and housing walls so that as much as the thermal processing medium is possible is forced through the spiral stack for processing work products carried on the conveyor system (22).

A thermal processing apparatus (20) includes a spiral conveyor system (22) configured into an ascending spiral stack (26). An air balance tunnel (40) includes a tunnel housing (76) positioned inside of a thermal processing chamber adjacent an outlet opening (36). A conveyor belt (24) travels through the housing on its way out of the processing chamber. An air pervious ejector assembly (78) is positioned within the housing at an elevation above the conveyor belt (24). An air pervious evacuation sheet (80) is located within the housing at a location beneath the conveyor belt (24). An air pervious cover assembly (150) is positioned over the conveyor belt (24) at a location just before the conveyor belt enters the air balance tunnel (40). The cover sheet (150) is connectable to the ejector assembly (78) so as to remove the ejector assembly from the tunnel housing (76) by manually moving the cover assembly (150).

A conveyor belt (36) is arranged in tiers at spiral stack conveyor unit (32) and/or (34). A ceiling or top sheet (58) is positioned over the spiral stack(s). A circulation fan (60, 62) draws thermal processing medium laterally from the tiers of the spiral stack, up the exterior of the stack and across the top of the stack above the ceiling or top sheet and through a heat exchanger (64). The treated thermal processing medium is then routed across the remainder of the diameter of the spiral stack and then down the side of the spiral stack diametrically opposite to the circulating fan thereby to enter the spiral stack in a lateral direction diametrically toward the circulating fan. At least one opening (70) is formed in the ceiling downstream of the heat exchanger and into the interior of the conveyor drive hub. The outer wall of the drive hub is partially open thereby to provide an alternative flow path for the thermal processing medium to enter the spiral stack from the interior of the drive hub.

A transport device for conveying a flowable material, comprises a screw conveyor for collecting the fluid from a collecting zone and transporting the fluid to a destination zone. The screw conveyor comprises a spiral which is wound around a shaft extending along a longitudinal axis and an outer casing which at least partly houses the spiral. The spiral has a plurality of turns. The outer casing has an inner surface facing respective head surfaces of at least some turns. Between two consecutive turns and the outer casing there is a compartment. The outer casing is made at least partly from a deformable polymeric material in such a way that the outer casing deforms radially and reversibly towards the outside when a solid particle of the flowable material conveyed by the spiral is interposed between a head surface of one turn and the inner surface of the outer casing, to allow the solid particle to be transferred from one compartment to a further compartment adjacent to said compartment passing between the head surface of the turn and the inner surface of the outer casing.

A spiral conveyor has a drum extending from a bottom to a top and having a transition height. The drum includes a plurality of drive bars, each having a drive side parallel to an axis of rotation of the drum. The drive side extends in length from the transition height to the top or the bottom of the drum (depending on configuration). The drive bars are spaced apart around a circumference of the drum. The drum includes a plurality of transition members, each having a drive surface. At least a portion of each drive surface is at an angle to the axis of rotation of the drum such that over an infeed distance, the circumferential location of the drive surface of each transition member is advanced by a collapsing distance of a corresponding modular belt. The spiral conveyor further includes a helical support around a circumference of the drum.

A helical conveyor for conveying piece goods comprises a frame and an endless conveyor belt which is drivable with respect to the frame along a helical track which extends about a centerline. The conveyor belt comprises discrete supporting members each comprising a substantially rigid slat and a roller. The slats follow a first helical path including a first inclination angle along the first helical path with respect to a base plane extending perpendicularly to the centerline and a second helical path including a second inclination angle along the second helical path with respect to the base plane. Each of the rollers is mounted to the corresponding slat such that the difference of an angle between the rolling direction and the base plane and the second inclination angle is smaller than the difference between the first and second inclination angles.

A helical conveyor comprises a belt having a transport section for transporting products where the belt follows at least partly a helical path between a lower end and an upper end of the transport section and a return section where the belt follows a path. The conveyor comprises a lower end reverse guide for turning the belt upside down and reversing its direction of movement between the transport section and the return section at the lower end of the transport section and an upper end reverse guide for turning the belt upside down and reverting its direction of movement between the transport section and the return section at the upper end of the transport section. The return section leaves the upper end through a horizontally oriented upper return section portion and the return section leaves the lower end through a horizontally oriented lower return section portion.

A freezing spiral net chain structure includes a plurality of chain links successively arranged in a travelling direction of a rail. Transmission teeth are arranged at inner ends of the chain links. Engagement teeth are arranged at two sides of the chain links. The engagement teeth of the adjacent chain links are engaged with each other. Axial holes are disposed between the mutually engaged engagement teeth. Rotary shafts are inserted into the axial holes. A metal piece is connected between outer ends of every two adjacent rotary shafts. The metal piece may bear a load from an outer-end spiral net, and since a coefficient of expansion of metal is smaller than that of plastic, deformation between the adjacent rotary shafts as a result of cold shrinking is reduced. The metal piece is different from the rotary shafts of the plastic spiral conveying net chain in terms of pitch.