Check bins and bags on cold November days

November 6, 2013 - Issue 28

When outside air is colder than stored canola, another moisture cycle begins within the bin. The grain mass on the outside edge cools first. This colder air migrates down through grain along the bin wall then up through the central core, picking up warmth and moisture along the way. This creates a pocket of humid and warmer air at the top of the central core where spoilage and heating can start.

Turning on the aeration fans for a day or two during the first cold week of fall can help put chills up any bin that hasn’t cooled down to a safe level. However, aeration can be tricky at cold temperatures. Check the aeration fan’s capacity for the amount of CFMs (cubic feet per minute) to ensure the fan capacity is matched to the size of bin. Fans with limited capacity will not be able to move the appropriate amount of cold air throughout the dense mass. This can create a moisture front within the bin, which can create a crust layer. With restricted air movement, spoilage could begin along the moisture front. This crust can also hang up and create a challenge for unloading.

Grain storage bags were a popular way to store a lot of the bumper crop this fall. Any canola in bags may be the canola you want to move first, as bags are generally considered safe for short term storage only. Moving bagged canola first also avoids the inconvenience of unloading bags in the snow (although we may be too late on that front for some) or in the soft muck of spring.

Checking bags is a little more difficult than checking bins. University of Manitoba researcher Chelladurai Vellaichamy, who studied bag storage of canola, says: “To check the temperature and moisture in our Prairie conditions is really an impossible task for farmers. The only way to measure moisture is to make a cut in the bag and take samples using grain probe. But closing the cut is not possible in winter. To check temperatures we can use remote temperature sensors (like Hopoware) or thermocouples, but this is really difficult at the farm level. We have to attach them with the stick or steel rod then insert them into the bag through a small cut, and close the cut using special tapes. With the Hopowares we have to connect the hopos to computer to get the temperature data. For that, we have to take them out from the bag. Taking them out and placing them back in is not possible. From our experience, I can say that the major drawback in the bag storage system is monitoring of grains is not possible in our Prairie climatic conditions.”

For more on canola storage, read the Canola Encyclopedia chapter on monitoring stored canola.

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