CTM also design a whole range of bespoke screw conveyors, both shafted and shaftless. All of these conveyors are tailor made to suit the individual application such as length, material handled, throughput, horizontal or inclined, method of being fed, single or multiple outlets, cantilevered stockpiles or simply supported, fixed or mobile.
They can be from mild steel galvanised, painted or stainless steel if the environmental conditions dictate, stringer or lattice frame construction as the load bearing capacity dictates.
If the screws are shafted we endeavour to keep the support bearings external to the casing by using a large centre tube able to span the distance but in the event the screw is very long, either journal hangar bearings or ball bearing hangars are used if the design allows. If the screw is shaftless, they are generally supported on PE1000 full length liners and the with the absence of a centre shaft, the screw flight itself is generally a lot thicker to compensate (typically 25 – 30mm). The drives can either be shaft mounted or foot mounted/chain driven. CTM conveyors can be a variety of diameters currently from 150mm to 1200 mm wide and up to 30m or more in length.
Special design screws can be used to convey at steeper angles up to 30 degrees dependent upon the materials being handled.
Screws can be carbon steel, Hardox or Abro for high wear resistance, stainless steel for food quality or high tensile in the case of the shaftless design.
They lend themselves well to convey dirty material where non spillage, odour containment and hygiene is considered an important aspect of the design. They also require less maintenance and take up less room than a belt conveyor.
Screw conveyors can be designed to impart a mixing action as well as a cooling function to hot materials typically exiting a dryer or thermal process such as gasification, incineration or pyrolysis process.
The coolers can be twin or triple screw if required to create sufficient surface area to cool the product within.