Edward Cragg’s grain dryer automation system

Complex category third place

Electronics postgraduate Edward Cragg set about bringing the family farm’s 43-year-old Wilder Robomatic batch grain dryer into the 21st century by fitting it with a modern digital control and monitoring system.

The process involved getting the dryer’s analogue electrics to communicate with the modern system he was putting together.

To do this, he used devices called optocouplers, which allow the digital system to gather information from the original electronics.

© Edward Cragg

Once data could be shared between old and new, he built a control and monitoring system with its own LCD screen and keypad. This is fitted with a precise digital clock to give accurate timings for all the relevant drying stages.

All of the information from the display is published to a web page that can be viewed on a mobile phone or computer.

This means loading, drying and cooling times for each batch, plus input and output temperatures, can all be monitored remotely. The progress of each batch can also be viewed in real time.

See also: Automated mobile dryer simplifies harvest for 160ha grower

Pre- and post-drying moisture contents can be entered into the system, allowing it to calculate the remaining drying time for each load and stop the cycle at the correct point. It’s also capable of estimating the drying time for a batch if no moisture reading is entered.

Mr Cragg is now gathering data on the relationship between exhaust grain temperature and moisture for different crops. Once a sufficient bank of data has been gathered, the dryer should be able to operate largely automatically.