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| I've been around dryers for more than 30 years. Back then there was a company selling a low temperature dryer that depended on air motion with the added heat from a few large lamps under the floor. Not enough heat to raise the air temperature significantly. They did work, some years. And some years the grain molded in the bin because drying was too slow. And it molded ALL the grain. That company is no longer in business because the scheme didn't work every year.
ND may be cool and humid, but I think its not as humid as Iowa. I would not trust the CMC scheme here.
As for their air system, it depends on the grain being LEVEL and free of fines to make sure there's uniform air flow. I suspect the multitude of roof vents affects their profit more than the rate of corn drying. Normally the grain sets the air flow, not the roof vents. I don't detect a high velocity out the 4 roof vents on the 30' dryer just out side my back yard every year. For sure with the Shiver's auger system and some heat, the drying uniformity is dependent on level filling too.
Centrifugal fans can be selected for higher efficiency with considerable back pressure (as from several feet of grain) and often are overloaded when the back pressure is small (no grain or a thin layer of grain).
For a nieghbor who had only enough corn for one bin, I suggested he dry by setting the heated air temperature each afternoon (he worked nights) to the affternoon high ambient temperature. He dried that bin in 30 days (stirrators on) for electricity and one tank of LP. With an axial fan its a wonder his wife didn't shoot him though. The corn quality was superb. In my back yard the dryer was run with only enough LP pressure to get the air up to 90 or 95 degrees F and its never failed to dry well, with occasionally a bushel or two of crust on the outside walls, but often went to the feed mill at the elevator because of its bright color and high quality. Heated drying doesn't necessarily mean scorched corn.
If you can't wait a month to dry a bin with slightly warmed air, you can't wait two months to cry a bin with pressure, then adding some heat (which gets more expensive each year) is about the only answer. That heat can come from a solar collector, could come from burning corn stalks or straw, but its most conveninent to come from LP or natural gas. Sometimes we PAY for convenience.
The electrical costs of running a fan for a month or two to dry a bin are not trivial and there likely is an optimum warmth that gets more drying for the buck than air alone or lots of heat with normal air. I've not worked those out.
So I think the CMC scheme will pass, leaving behind ill feelings from some of those who have lost crops depending on it. Others will be lucky with good ambient conditions for a few years, then a clammy fall will mold the grain and they'll be out of business.
Gerald J. | |
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CMC pressure cure bins
