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Frequently
Asked Questions about Grain Drying
To get an answer to your own question, click here
When should I run my fans? What are the minimum weather conditions required? The following table describes the estimated safe storage time for cereal grains at different grain moisture contents and storage temperatures. The second table explains the moisture content cereals and oilseeds will dry down to when exposed to air of different relative humidity. Since air with a relative humidity of 70% will dry cereal grains to approximately 14% moisture content, it is advisable to start the fans as soon as practical, and to run them until the grain is dry, or the grain temperature has been reduced sufficiently to allow long-term storage. Grain takes much longer to rewet than to dry, so short periods of inclement weather are no need for concern. Generally, an air temperature of at least 10 degrees Celsius is required to achieve any reasonable drying in a NAGD system.
Although specific conditions may prevail, the crop is probably better in the bin than in the field. Provided harvest conditions allow you to put the grain through the combine, cold grain will store relatively well at moisture contents in excess of dry. Although you will have to keep a close eye on the grain in storage, cool storage temperatures do extend the safe storage time, allowing the grain to be harvested, stored and dried after harvest. What about adding heat to my NAGD system? Adding supplemental heat to NAGD drying can improve the drying capabilities of NAGD systems under humid or moderately cool conditions. The drying ability of NAGD systems depends on the temperature and relative humidity of the air entering the grain bin, which should be 10 degrees Celsius or greater and 70% humidity or less. The basic recommendations for adding heat to NAGD systems are: a) Limit the increase
in air temperature to 10°C. When adding heat, remember safety first and use only properly controlled electric, natural gas or propane heaters to avoid the risk of “flame outs” and gas explosions. Kerosene or fuel oil burners may leave an odour on the grain and should be used with caution. How long will it take to dry grain in a NAGD system? The time required to dry grain in a NAGD system is difficult to predict, and is best based on the experience of the operator. The time required to dry grain can be reduced by adding heat, increasing the fan size, reducing the amount of grain in the bin or any combination of these factors. Although a NAGD system will enable farmers to safely store grain until spring, actual drying of the grain may not be possible during the late fall or winter months. What about hot air grain dryers? Hot air grain dryers will dry grain virtually under any condition. However, energy costs do increase as the outside temperature drops. If a heated air grain dryer is a necessity, use it as soon as possible after the grain is harvested to minimize the risk of the grain spoiling in storage, and to minimize the cost of operating the grain dryer in cold conditions. Are there custom grain drying operators? Yes. Most major grain companies and inland terminals offer grain drying, and many farmers with heated air grain dryers will do work on a custom basis. You may contact the feed listing service operated by Saskatchewan Agriculture and Food to search for, or advertise, custom grain drying services near you. Call 1-800-667-7564, or visit the Web site at www.agr.gov.sk.ca under “Feed Grain and Forage Listing.” What precautions should I take with a heated grain dryer? Although each type of heated air grain dryer has specific advantages and disadvantages, operators of heated air grain dryers need to consider the following points: a) Maximum Drying Temperature The Following Chart provides maximum safe operating temperatures based on the type of grain and its end use. Excessively high temperatures can reduce germination, milling quality, or damage the grain, resulting in a downgrading of the product. Use an accurate thermometer to check the actual operating temperature of the grain dryer.
b) Moisture Rebound Grain dried in a hot air grain dryer will regain moisture after it leaves the hot air grain dryer. To account for this, the grain should be slightly over dried to ensure it does not rebound above the target dry moisture content. The rule of thumb is to over dry .1% of moisture removed (i.e. target 14.2% for grain going in at 17%). However, this will vary from dryer to dryer, and among types of grain.Ensure that grain exiting the dryer is adequately cooled so that spoilage in storage does not result. Cooling canbe completed in bins equipped with fans, but must be done immediately on exit from the grain dryer to avoid spoilage or heating.
If you have a natural gas service into your yard site, you have two options to consider: 1) Running a second
service to facilitate the supply of natural gas to your grain dryer; and You are required to have a representative from SaskEnergy to visit your farm to recommend the best option to follow. Each farm site is handled as a specific case. Information and parts for converting your propane dryer to natural gas can be obtained from the dryermanufacturer. Should it be economically feasible for you to make the conversion, the cost for operating on natural gas is about four times less than operating on propane. One point to remember when operating on natural gas is you will be required to enter into a contract that limits operating your dryer to off peak gas consumption. The grain drying season when on natural gas will end about the end of October and not start again until April. Additional information on using natural gas in your grain drying operation is available from your local SaskEnergy office. Where can I get more information? Detailed
specifications and test results on grain drying fans, equipment and hot
air grain dryers is available from the Prairie Agricultural Machinery
Institute (PAMI) in Humboldt at 1-800-567-7264, as well as from independent
equipment manufacturers and suppliers. Production
information is also available by calling the Saskatchewan Agriculture
and Food's Agriculture Knowledge Centre at 1-866-457-2377 Additional grain drying resources can also be found at: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/cer1204 http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex4509?opendocument | |||||||||||
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