Re: Screw Conveyor Design
As far as materials of construction is concerned, ASME VIII or similar pressure vessel codes give design stresses for a range of materials which would operate at this temperature. Use a PV code to select a material suitable for your design temperature that is also compatible with your bulk material. It is difficult to be more specific as you don't tell us what material you are handling.
Once you have selected your material of construction, calculating the thermal expansion for the various parts is easy.
I would expect the the above to be the least of your problems though. Bearings, drive systems, etc will all be subject to high temperatures or will need cooling systems.
I am afraid your question is much to general for anyone to help much on this board, if you rely on comments from a discussion board to design of equipment for this duty I am afraid you are guaranteed to hit problems.
The right solution to this problem is to employ a competent engineer or engineering company to design the equipment for you. ■
High Temperature Screw Conveyors
304 Stainless screws can handle bulk material to well over 500 degrees C, so material of construction is not a problem. Various arrangements can be made to deal with seals and bearings, from using thermal barriers on rigid couplings to water cooled housings. Accomodating thermal expansion much depends on the length of unit. A good way to deal with short feeders is to cantilever the screw from double bearings at the drive end. This can often be extended to form a plug seal to provide a thermal, vapour or pressure barrier from the receiving enironment, but this is not a technique to be employed by the inexperienced. Overall, this duty is run-of-mill for specialists. There are other hazards for those who adapt standard kit, such as excentric casing distortion due to biased loading location of the material in transit and sometimes effects on the product conveyed due to the higher viscosity of the ambient gas. RPD's advice on consulting a specialist merits consideration, as problems may cost more than the equipment if things do not work well. ■
Screw conveyor design
Dear sir
We have to procure screw conveyors and bucket elevators for conveying material having 400 degree centigrade temprature . what are the precautions to be considered for thermal expension
Which MOC of componants will be most suitable
A R SINGH ■