Counter-Flow Grain Drying
As an informed grower of quality grain, you want to be aware of the most up-to-date methods of caring for your product. Once your grain is harvested, it is extremely important that it is dried to the proper moisture content before transferring it to storage.
The method you use to dry that grain is as important as the method of harvesting.
Shivvers wants you to understand the method know as “Counter-Flow Drying”.
Most grain dryers on the market today use the method known as “Cross-Flow Drying”. In this method, air is forced horizontally (crosswise) through a column of grain moving in a downward direction. This “cross” flow of air to the column of grain is where this method gets its name. The column of air is usually about 12-14 inches thick. The air is forced from one side of the column, through the grain (raising the temperature of the grain rapidly) and then the heated air is exhausted into the air.
In “Counter-Flow Drying”, the air is moving upward (counter to) the grain that is moving downward, thus its name “counter” flow. This is accomplished by forcing the heated drying air up through a perforated drying floor inside a bin, through a bed of grain at least 3-8 feet deep and exhausted out the top of the bin.
The advantages of the “Counter-Flow Dryer” are efficiency, uniformity of grain moisture and higher grain quality. Since the heated air is in contact with the grain for a longer period of time (due to the depth of the grain versus a thin column) more of the heat is used from the heated air to remove moisture before it is exhausted. This results in higher efficiencies.
Since the grain is moving toward the heat source and then removed when dry, all the grain receives the same amount of heated air (not just heated from one side) This results in uniformity of drying of all the grain.
Since the grain is in contact with the heated air for a longer period of time at a lower temperature, the “stress” on each kernel is less resulting in less “stress fractures” and higher test weight with the removal of the same amount of moisture.
Counter-Flow Grain Drying is an innovation of Shivvers Manufacturing, the Grain Drying Specialists, as a “common sense” method of drying the valuable grain you have invested in and worked so hard to produce.
What is Retention Time?
Test Weight has everything to do with Genetics and the maturity of the corn. We can't make test weight, but we can RETAIN what's there. The slower the drying process, the more test weight is retained. The faster the drying process, the more test weight is lost. The amount of time the corn is in the drying process is known as RETENTION TIME. A kernel of corn travels from top to bottom of a Cross-Flow Dryer in about an hour. At 6' of grain depth, in a Shivvers Counter-Flow Dryer, that kernel takes about 12 hours before it leaves the bin. This longer Retention Time allows the corn to retain 2-4 more pounds of Test Weight.
Since a larger volume of grain receives the heat inputed throughout the bin, each kernal is dried more gently as energy is fully utilized. The results are dramatically higher test weights with added profit due to less energy usage.
Managing Stored Grain
Review the basic principles of managing stored grain.