Design support for charcoal extrusion process

Shafts  (102)The social enterprise Appropriate Energy Saving Technologies Limited makes and sells charcoal briquettes from recycled agricultural waste in Uganda.

Our biggest problem at the moment is that the shaft in the charcoal extruder wears out a lot. We have tried  case hardening and are now considering to buy another extruder that can make 1 ton of briquettes per hour or fabricate one with a better, stronger material. We are seeking advice from experienced engineers on how make this process faster and reduce wearing.

Volunteer opportunities are available in our enterprise especially in improving our extruder.

An image of the machine is below, and you can see the shaft that wears off a lot at the left.

[Editor’s note: Additional information about AEST and their product is available in the E4C Solutions Library.]

If you’re interested in providing support please contact


AEST Equipment




Leave a Reply

Already a member? Sign in and comment. Your email address will not be published.

  • Ryan MacDonald says:

    My first thought is that your problem may not be a hardness issue but corrosion issue I know that charcoal will always contain some ash and ash is vary acidic. This will cause your metal to quickly rust which is then quickly removed exposing new metal to the ash to repeat the cycle. This would explain why changing the hardness has had little to no effect on wear. The easiest and low cost solution would be to use a protective coating on the shaft, unfortunately I do not know what type of coating you should use (you could start with something like Teflon) but luckily there is many venders that specialize in metal coating and can give you good advice.

  • vikas.chawan says:

    I suggest u to use EN-353 or phosphorus-bronze as a material for shaft.
    EN-353 has HRC:-56-58

by engineers.
for everyone.

E4C Membership is a curated experience! When you become a member, we will tailor a unique user profile for you based on the way you engage with our content over time. Your actions and preferences will allow us to serve you content that is most relevant to you. In addition, becoming an E4C member grants you access to exclusive engagement opportunities and the E4C newsletter.

Join E4C and become a part of a global community that believes engineering can change the world!

Become a Member