Consistency is important and maintaining consistency at volume is critical to profitability. With facilities cleaning at volumes ranging from 100 to 5,000 bushels/hour, equipment that performs at those speeds pays for itself in a fairly short period of time. Now that the grain is cleaned, managers need to ensure its quality doesn't diminish when stored.
Know What You're Dealing With
For keeping grain in good condition during storage, the rule of thumb is keeping it cool uniformly in the bin — ideally somewhere between 35 and 50 F. However, one expert cautions operators that ever-changing variables will impact the processes needed to obtain those optimal temperatures.
"Each crop is as different as the growing season it took to grow it," says Bill Sturtz, manager, Aeration Division, Rolfes@Boone, Boone, IA. "A late, wet season like last year requires much different aeration strategies than a drier year. And as storage tanks keep increasing in size and capacities, you need to constantly fine-tune your systems for the best results. To maintain an ideal temperature between 35 and 50 F in a 105-foot-diameter steel bin takes some management."
As outside temperatures warm, head space temps also rise quickly, thus increasing the prospects of insect and mold damage.
Sturtz says one tip for proper cooling in the newer, larger bins is to install roof exhausters to disperse 135% to 150% more air out the roof than the amount produced at grade. (e.g., 100,000 cfm at grade/135,000 cfm or more pulled from under roof). Wiring these units independently and separately allows them to be operated for extended periods of time. It is suggested to install several units diagonally from each other and rotated to be operated to dissipate heat, wear, and to better manage over space temperatures.
"Designing different configurations often works wonders but it still requires that the customer know their exact needs before installation," says Sturtz. "Tell us the commodity stored, moisture content upon arrival, and we can suggest the air delivery for best results.
"If we are retrofitting an older system to handle higher moisture levels to alleviate pressure on the dryer, one concern is if there's adequate power available to handle the increased horsepower," Sturtz adds. "These are all important questions that need answers before we design a system."
You Get What You Pay For
All the manufacturers interviewed agreed on one major point: "You get what you pay for." Skimping on cleaning or aeration equipment simply because of the cost will, indeed, cost you money down the road.
The key is knowing what your customer wants, understanding whether or not you have the current system to meet those needs and having the foresight to purchase the equipment that will do the job today and in the future.
Conditioning and cleaning goes a long way in maintaining grain quality, but testing is required to verify that it meets certain quantifiable standards. Whether the commodity ends up being exported overseas, or shipped to domestic customers, it must be tested for aflatoxin, a harmful mycotoxin regulated by the USDA Grain Inspectors, Packers and Stockyards Administration.
Mycotoxins are naturally occurring chemicals produced by a variety of molds. Conditions like moisture, humidity and heat are all conducive to mold formation, and anytime mold is present there is a possibility that mycotoxins could form, greatly reducing the quality of the grain.
GIPSA's acceptable limit for aflatoxin is 20 parts/billion. Quantifying the aflatoxin level in parts per billion requires the right equipment, proper sampling and sub-sampling, and careful testing.
"The presence of mold doesn't automatically mean mycotoxins are present," says Paul Pfeiffer, territory manager, milling and grain for Neogen. "You can't just look at or smell a grain sample and get a proper diagnostic. A screen or test is needed to accurately determine mycotoxin levels. It's important because the more you know about the grain, the better you can evaluate its quality."
Grain handlers who have the available space can segregate grain according to quality, giving their customers exactly what they need.
"Segregating your grain helps meet a customer's quality expectations," says Pfeiffer. "By segregating the 10 parts/billion, 20 parts/billion and 50 parts/billion, you can provide different qualities for different customers."