Ideas Needed on Drying Cassava Flour in Malawi!

We need ideas on improving the cassava flour drying process for an EWB project in Malawi. This is your chance to put design skills and innovation to work for Dorothy!

We need to improve existing drying shed technology to produce high quality cassava flour more quickly. We need input on ideas to retrofit the process before the cassava harvest begins.

Background

The current drying shed is a wooden frame, covered in sheet plastic, with two plywood tables running the length of the shed. It takes approximately 3 days to process 500 kgs and we need to improve this. In order to meet processing and quality needs, the process needs to:
- Dry flour quickly
- Be free of dust and other particles
- Be free of insects and other pests
We have some available technical expertise but are interested in getting more input from other sources. Solutions need to be cost effective and not dependent on electricity.

Main Ideas for Improvement

1. Improving Airflow
We think that drying time is dependent on both heat and humidity and that improved airflow will dramatically improve the process. The existing shed has small vents between the roof edges and walls but air circulation remains poor. Our leading idea is to install a chimney and small vents at the shed bottom while sealing all other openings. We think a difference in vent height should create a pressure difference to draw air through the shed.

2. Increasing drying area
More surface area for drying should also accelerate the process. We considered the idea of constructing another shed but feel this approach may not be the most cost effective. Ideas for increasing area within the existing shed include adding a second level of shelving and replacing the current drying surface with a breathable material. Mafayo, the factory owner, is currently adding a second layer of shelving.

Required Input

We need ideas for solutions and feedback on what we already have. Any input needs to be in by July 6 so we can finish improvements before the harvest. Here is your chance to do some engineering design for Dorothy!

Thanks!

The Cassava Value Chains Team
Malawi Division