If you have no experience I would advise you to steer clear of offering deisngs for high temperature screw applications. The ability to make screws is a separate skill from applying them. Equipment has to satisfy both the mechanical and process functions and the simplicity of screw conveyors for routine handling duties cause many to lack appreciation of the potential hazards of custom built screw feeders for specialised applications. Ajax has been making screw equipment for temperatures up to 1800 degrees F for many years and employing techniques to protect screws from high temperatures, aggressive atmospheres, pressure differentials, abrasive, countering segregation, attrition, mixing and many other functions. Combined with a knowledge of powder technology, there are many factors to take into account when designing special screws for high temperature applications so the direction that I would point you to is towards specialists, and offer them your fabricating experience. ■

I would be pleased to deal with any queries via lyn@ajax.co.uk ■

Dear friends,

I am not a screw feeder manufacturer, but I have designed very simple screw feeders for hot sponge iron at temperatures up to 800 degrees C, and pressures up to 4 Km/cm2.

These are not fancy, good looking, expensive items. They were designed for data gathering purposes in the HYL Hi-Temp project and for capacities of up to 16 Metric Tons/hou

HYL did not pursuit any commercial application for these screw feeders, as far as I know, they are sticking with their hot rotary valve design.

On the other hand, HI-Smelt is using a German design hot screw feeder which is commercially available. You might be able to get information through Outokumpu Metallurgie which were the ones managing the project.

Regards,

Marco Flores ■