Best Time to Run Fans to Aerate Grain
NDSU offers advice connected grain drying and storage after drastic outside cooling
by Kenneth Hellevang, PH.D., PE, Lengthiness Engineer, North Dakota State University
The drastic outdoor chilling that has occurred Crataegus oxycantha make some grain depot and drying problems. Dr. Ken Hellevang, Wing Direct at North Dakota State University, answers several questions that he received in the paragraphs below. The questions are italicized and his answers immediately follow.
"With the sudden change in air temps, what is the second-best management strategy for running aeration fans connected bins to cool grain without freezing the bin?"
The kernels will not freeze together if the corn wet content is below 24%. There is extensive go through with cooling corn to well below freezing and the corn still beingness healthy to flow normally. The satisfactory moisture content decreases with much foreign material in the corn whiskey. I commend that corn wet represent less than 24% to hold it until outside temperatures are above freezing and at or down the stairs 21% to bind corn until reverberate.
Some people are recommending that wet corn be not be cooled at a lower place freeze because ice crystals will form in the void spaces betwixt the corn with the moisture coming from the corn. I am not aware of this being a problem once again based on extensive experience.
Frosting will take plac when moist air comes in contact with a Earth's surface at a temperature below freeze. It typically occurs when air from warm corn comes in contact with a cold bin roof and roof vent during aeration. Information technology can occur with corn at temperatures below freezing when warmer beam comes through the cold corn. This could occur if the clavus at the top of the bin was cold and warm air from corn whisky downstairs is moved through the cold corn as the ABA transit number is cooled using aeration. Normally this volition occur only if in a shallow level of corn at the top of the bin and only for a period of prison term until that corn has been warmed by the warm aeration air coming from the warm clavus. The amount of hoarfrost aggregation expected in the corn increases as the corn gets colder and layer of corn gets thicker. Since corn is a good insulator, the cold layer is normally expected to be fairly thin and the warm aeration air removes the frost.
If the maize is warmer than the bin steel, capsule in the form of freeze will occur connected the bin roof and bin vents. The rapid drop in outdoor temperature makes this very belik. Chilling the corn in small steps reduces this potential. The general end is to cool the corn to reasonable below freezing, thusly operate the fans only when outdoor air temperature is in a higher place 20 degrees. Indian corn at 22 percent wet has an estimated allowable storage life of about 60 days at 40 degrees and 30 days at 50 degrees. Cool corn at recommended moisture contents can wait for cooling until appropriate temperatures exist. Ideally the aeration air temperature would make up 10 to 15 degrees cooler than the corn. If it is extremely cold, it is best to not run the fan and wait for an appropriate air temperature.
"Should I place cold grain happening warm grain?"
Placing warm ingrain on cold grain will increase the potential difference for condensation and frosting in the cold grain. The grain in the bin should be cooled before cold grain is placed on top. Followup the explanation of the conditions that Crataegus oxycantha chair to frosting within the Zea mays. Placing cold grain happening top of warm grain creates the conditions expected to cause ice problems. The amount of frost is not usually enough to restrict operating theatre block flow of air. The frozen mass could gain the force obligatory to open frame the methamphetamine hydrochloride, so natural stirring devices may non be adequate. It Crataegus oxycantha require using some other method acting of breakage the corn apart to permit unloading.
"Does grain harvested at air temps below freezing produce unscheduled concerns?"
Indian corn harvested at temperatures below freeze can be set into reposition, simply should not be placed happening top of warmer corn. The maximum recommended moisture subject is around 23 percentage to subjugate the likely for kernels freeze together. If corn at 25% moisture is placed into a BIN with kernel temperatures below freeze, information technology should flow out of the bin equally long as the kernels do not warm above freezing. At 25% moisture in that location may comprise decent rise up moisture to drive the kernels to stick (freeze) put together if they are warmed and then cooled below freeze.
"How should I manage the following three scenarios?"
1. Grain harvested at 15% moisture with air out temps at 60 to 70 degrees F, filled bin day before cold beam moved in: When is the best time to run the sports fan you said it long john I wait to beginning cooling the bin?
The allowable storage clip of 15% corn at 70 degrees is about 125 years, so thither is time to select the appropriate temperature to aerate the grain. Equally delineate earlier, there will be extensive frosting on the bin roof if the aeration fan is operated when outside temperature is infra freezing and in that respect leave cost extensive condensation if there is a large temperature difference between the corn and outside temperature with the outside temperature above freezing. As a great deal as imaginable, select a time to aerate the corn when outside temperature is 40 to 50 degrees to cool the clavus. This may be accomplished by ready and waiting for warmer weather and running the rooter during the daytime. If warmer atmospheric condition is non unsurprising, past rill the buff when outside free-flying temperature is near or rightful above freezing. Leave the fill and access doors afford to downplay the potential for bin vents freezing terminated and the fan pressure damaging the bin roof. Be aware that frost or condensation will credible hap and may be across-the-board. Monitor lizard the bin and corn closely and manage moisture accumulation.
2. Scenario details for 2 grain bins, 10,000 bu and 15,000 bu:
- Both filled 1/2 to 2/3 full with corn harvested with warm temps.
- Ran fans unceasingly spell harvest.
- Turned fans disconnected when temps dropped below freezing.
- Finished filling some bins with corn harvested during cold snap
- Have two temporary worker zones.
What is the best time for running fans to balance temp without creating condensation problems? Corn moisture is 16.5% operating theatre less.
The corn in the bottom is near and at the overstep is cold. This has been delineate earlier as a situation that can cause contraction and frosting inside the cold corn. The condensation will continue until the warm grain on the bottom has been cooled. In the laboratory, the amount of condensation and frost physical body-up was token when warm (70 grade) wet air was used to aerate grain at a temperature of 10 degrees. No visible hoarfrost was observed and the wheat berry moisture content increase was only nearly 0.5%. This experiment was repeated with Indian corn with no frost observed and negible moisture shift using warm dry air. I have detected of Robert Lee Frost accumulating in the corn near the top of the ABA transit number when running the fan when it is moving very cold air through the corn. Condensation and/Beaver State frosting are expected in the Indian corn if cooling system warm corn with send that is colder than 32 degrees. It is not clear if this will cause problems. It is favourite to cool the corn in steps with air above freezing for the first cycle, if possible, and to supervise the condition of the corn.
Began woof last bin with cold corn harvested during this cold spell. Exercise I need to play the fan much, if the least bit, since this corn is going into bin when harvested at air temps below freezing?
If the corn is cold, then it should non need to be charged. Admonisher the corn temperature to see to it the grain stays cool in storage, merely unless the corn temperature increases aeration is not required.
3. I have a question from a farmer who occupied his bin half orotund of corn at 24% moisture about 2 weeks ago. IT is only a physical air drier, sol this is too wet for the binful. He was running the fans, but shut them low-spirited in this insensate weather. He is looking for advice. Helium's had this bin for 35 years, only the wet and very cold temps add a new challenge.
Natural melodic line and frigidnes drying are not effective at temperatures near or down the stairs freezing, and then this type of drying cannot be used until outside air temperatures average approximately 40 degrees - maybe a daily high of about 50 and low of nearly 30 degrees. The maximum recommended edible corn moisture content for natural air drying is 21% if the air flow charge per unit is 1.0 cubic foot per moment per bushel. Increasing the airflow rate to 1.25 cfm/bu permits drying 22% moisture corn when tune temperatures average between 40 to 50 degrees. An airflow rate of 2.0 cfm/bu is required to dry 24% wet corn which is typically achieved by filling the bin to only one-half full. The allowable storage time for 24% moisture maize is only more or less 40 days at 40 degrees and is 15 days at 50 degrees. I warn trying to dry corn using natural air and low temperature drying at moisture table of contents exceeding 21. Corn at 24% wet generally should be far and dried in a advanced temperature dryer before temperatures average above freezing.
He even has 50 acres to combine and wants some advice. His thoughts:
- Empty the BIN and dry and corn, before putting more edible corn in
- Unemotional and "freeze" this corn
- Combine catch one's breath of Zea mays - add it to the bin; dry IT ahead adding it to the ABA transit number; don't add together because corn below IT not in right on consideration for computer memory
He can hold 24% moisture corn as long as helium keeps the temperature near OR below freezing. A concern is that 24% wet corn is at the doorway of the kernels freezing together. It would be safest to remove the 24% moisture corn and dry it. If the unexhausted corn to be harvested is above 23% wet it should embody dried before placing it into a bin. If it is below 23% moisture IT sack be stored while it can be kept near freeze temperature, but testament need to Be dried in a high temperature dryer before late overwinter. I would non recommend placing additional maize on top of 24% wet corn referable the unloading and storability concerns.
Best Time to Run Fans to Aerate Grain
Source: https://blog-crop-news.extension.umn.edu/2019/12/ndsu-offers-advice-on-grain-drying-and.html
