Grain crops are required to be relatively dry and relatively cool in order to be usable. When grain is not sufficiently dry or cool, various issues arise which may make the crop less desirable and, in some cases, unsalable. For example, with sufficiently high levels of moisture content or sufficiently high temperatures, infestation by insects and/or microorganisms may occur. In addition, seed germination may result within the crop or the crop may otherwise be unacceptable for sale to consumers as a result of degraded appearance and/or taste.
In order to successfully harvest grain crops, it is necessary that the grain be both suitably cool and suitably dry. Some traditional approaches for producing usable grain is to harvest grain only during dry periods and/or using the sun to dry the grain and/or using in-line aeration fans to cool the grain. As may be expected, in many regions, the relative humidity of the air is typically high enough that these techniques are not reasonably available or they are only available during very short time windows during the year. This is due to the fact that in order to cool the grain using, for example, an aeration fan, the outside air temperature must be lower than the current temperature of the grain. Similarly, in order to dry the grain, the ambient relative humidity as well as the outside air temperature must be lower than that of the grain.
The foregoing weather conditions exist only on a very limited basis, particularly in hotter/more humid regions, thus severely limiting the ability to use the aforementioned techniques for drying and/or cooling grain. Even if suitable conditions exist, the timing of the crop maturity and required delivery time frames may not coincide with suitable weather conditions where the outside air is sufficiently cool and dry.
Additional drawbacks are associated with the use of aeration fans for cooling in that they can be expensive and use significant amounts of energy at a high cost. Because these fans are expensive and use a lot of power, many farms tend to have a number of fans which is significantly less than the number of grain bins. As such, it is necessary to move the fans to where the grain is or, alternatively, move grain around to the location of the fans. Even more problematic is the fact that these fans actually damage the grain in higher relative humidity conditions, if operated during those conditions, because they are introducing additional moisture to the grain notwithstanding that they may be cooling the grain to some degree.
In terms of grain drying, relying on the sun to dry the grain is not ideal for many reasons. For one, it requires the grain to be taken out of the grain bin so that the sun may directly act on the grain and moisture is allowed to escape. Perhaps more importantly, sun drying is generally not effective due to the unreliability of weather conditions and the potential for rain, clouds and other conditions which prevent drying or even introduces more moisture than was originally present.
Another known technique for grain drying is the use of in-line dryers. These dryers are used to blow warm air over the grain with the intention of drying the grain through the application of heat. In some cases, these dryers are employed on the farm with the warm air being introduced directly into the grain bin used for storing the crop. In other cases, grain may be moved to specialized facilities specifically for grain drying using these dryers.
There exist a number of drawbacks with the foregoing grain drying systems which blow warm air over the grain. For one, these dryers use significant amounts of energy and they can act in effect like an oven, resulting in over-drying and/or cracking of the grain. Perhaps more critically, these dryers are ineffective in conditions of high relative humidity in that the air introduced may be warm but it is also moist which often results in an increase in grain moisture content as opposed to the desired decrease. For example, if it is raining, it is not possible to run the drying fans as their use would cause the introduction of a significant amount of moisture into the grain under these conditions. As a result, the dryers are typically only used during periods of relatively low humidity which can be severely limiting depending on the region and the specific harvest schedule for the crops.
While farmers have available to them various existing techniques for drying and cooling grain, none of the current systems and/or methodologies are ideal. Some are limited in terms of when they are available for use, others are inefficient in their use of power, yet others actually harm the crops when used when they shouldn't be and still others require the movement of the grain from bin to bin or even to a remote location.