Canola School: Can your fans keep up with large bin size?
The average size of a new grain bin in Western Canada has grown dramatically in recent years. 1,650 bushel flat-bottom bins, while still needed in some cases, are turning into relics of the past.
“Right now, the average bin going up is around 25,000 bushels,” says Lorne Grieger of the Prairie Agricultural Machinery Institute (PAMI), in this Canola Schoolepisode.
While the benefits of increased capacity and efficiency are obvious, large bins do pose new challenges, especially with small seed crops like canola, where density makes it harder to push air through the crop versus corn or soybeans.
In fact, PAMI’s research indicates the common electricity setup on many farmyards isn’t capable of pushing air through a 25,000 bushel bin filled with canola.
“Typically most farms have single-phase power, which really limits your fan size to a 10-horse motor. We found we’re actually able to stall that fan out before we were able to fill the bin,” says Grieger.
During PAMI’s testing, static pressure started to stall the fan at around 17,000 bushels, he says. “So your fan could be running, but you might not be putting any air through, which could be a potentially bad situation, especially with canola inside the bin.”
While bringing in three-phase power for fans with higher static pressure capabilities can be done, the easiest option is to not fill your bin all the way, and “understand what your capacity is on your fan compared to your bin height.” It’s relatively easy to measure back pressure, he notes. Some newer aeration systems come with pressure gauges, but there are also retrofit methods of gauging pressure.
In addition, PAMI is looking at the implications of spreading the top of the canola pile inside the bin, minimizing the peak.
Researchers found the gravity spreader provided a marginal benefit in grain surface distribution, a small decrease in airflow rate (an increase in static pressure), and no significant differences in airflow uniformity. However, Grieger notes these conclusions are only applicable to a gravity spreader since the grain distribution did not produce a completely level grain surface as intended, and were only measured on a partially-filled bin.
PAMI’s large bin canola storage research has been funded by Agriculture and Agri-Food Canada, the Canola Council of Canada, Alberta Canola, SaskCanola and the Manitoba Canola Growers.
Lorne Grieger joined Kelvin Heppner to discuss the preliminary findings from PAMI’s research looking at airflow in large bins for this Canola School video: