Spelt. Overcoming five hundred years of stagnation

Ewelina Kolankowska and prof. Dariusz Choszcz
Spelt is a crop forgotten by farmers and agricultural technology for five centuries. Prof. Dariusz Choszcz from the Faculty of Technical Sciences has built a machine for its cleaning and sorting, offering an innovative solution on a global scale.

Spelt, an archaic wheat variety, was well-known in antiquity. In Europe, it was still popular in the Middle Ages. Currently, it is rarely grown, as agriculture abandoned spelt growing. It is not a very efficient crop and its seeds are also surrounded by mini-spikes, so its threshing requires additional work. However, spelt has been lately back in favour, due to its values and researchers, including the University of Warmia and Mazury, have been working to develop new, more efficient cultivars.

While with new cultivars of wheat, people kept on inventing increasingly more efficient machines to harvest and clean its seeds, the technology of spelt processing did not leave the medieval stage. Prof. Dariusz Choszcz, the Head of the Department of Heavy Duty and Research Methodology in the Faculty of Technical Sciences, has been examining the processes of cleaning and sorting seed mixes throughout his entire professional career.

“My interest in machines to clean and sort spelt seeds is derived from the growing interest in this crop. It is still a niche plant, but it is experiencing a renaissance,” Prof. Choszcz explains.

He started his work on the machine for separating spelt seeds from chaff and for seed sorting five years ago. He involved his PhD student into the research, M.Sc., Eng. Ewelina Kolankowska.

A traditional harvester cannot be used to harvest spelt. These machines are designed for harvesting and cleaning the seed which is not hidden in mini-spikes. After several years of research, Prof. Choszcz developed a device for selecting and cleaning the spelt seeds. Actually, there are two devices.

The first one is a pneumatic separator, used for sorting the seed mix. After getting through this separator, spelt is pre-cleaned of weed seeds and is divided into four fractions, depending on the seed size. If it is not required, the number of fractions can be lower.

In the second device, the cleaned fraction of spelt seeds is deprived of the mini-spikes. This is a machine constructed especially for this crop. It consists of a replaceable steel drum, resembling a washing machine drum, which functions as a sieve. This drum features openings with shapes and dimensions established through experiments. A rotor with blades rotates inside the drum. Rotating blades, rubbing the seed against the drum interior, husk them from the mini-spikes. In this way, husked seeds come from one outlet of the machine and chaff from the other.

“The idea is simple, but it took us a really long time to determine the parameters for both machines,” Prof. Choszcz admits.

The devices designed by Prof. Choszcz and his PhD student, Ewelina Kolankowska have been successfully tested in the department under her supervision.

“We are going to improve them, to test and to search for a potential manufacturer,” the author declares.

Lech Kryszałowicz