Here you can read the most frequently asked questions about the PM-LUFT/Tornum Grain Cooler and Rice Conditioner. If you have any further questions please do not hesitate to contact us or order information online. .......................................................................... Is the grain cooler difficult and complicated to operate? No, just enter the following information into the Grain Cooler: Type of grain Moisture content Required temperature As soon as the Grain Cooler has received above information it will operate fully automatically. The same temperature and humidity will be maintained throughout the chilling process regardless of ambient conditions. Is it necessary to supervise the Grain Cooler day and night? No, the operation of the cooler is fully automatic. If something goes wrong an alarm is activated and the Grain Cooler will stop automatically. Can chilling take place in all types of silos or stores? Yes, as long as there is duct system installed. If there is no duct system one can easily be installed. Is it necessary to clean the grain prior to chilling? We recommend a high degree of cleanness for the grain being chilled in order to obtain the best possible results. What about condensation problems when grain is removed from the silo or flat store? Our experience has shown that there are no condensation problems despite the fact that the ambient temperature and humidity are often high. Are the problems of noxious insects reduced when grain is stored at low temperatures? Yes, due the fact that the chilling process begins as soon as the grain is received, insects have no time to multiply. At temperatures below 15°C (59°F) all stages of insects life activity are diminished and are unlikely to form any large infestation. When should the chilling process start? Temperature is the single most important factor when storing grain. Therefore cooling should start as soon as the duct system is covered with grain. Cooling then continuos as the silo is being filled and until the required temperature has been reached. Why should a Grain Cooler be used, isn't chilling grain using ambient air good enough? The most important factor when storing grain is to be able to control the temperature. As long as the temperature is being controlled grain having a higher moisture content than usually used for long term storage can be stored safely. Using a PM-LUFT/Tornum Grain Cooler it is always and regardless of ambient conditions possible to chill the grain to a safe storage temperature. Most frequently during harvest the ambient conditions do not provide any temperatures that make it possible to chill grain to safe storage temperatures, regardless of ambient temperatures, Does that mean that chilling can take place Also during periods with high relative humidity? All grain is hygroscopic meaning that it will give away or take up humidity depending on the conditions surrounding the grain. Because of this it is important to use the correct relative humidity when chilling grain. Using a PM-LUFT/Tornum Grain Cooler will provide air with a relative humidity that is in equilibrium with the moisture content of the grain, regardless of ambient conditions. So even if it is raining humidity will Not be added to the grain? Rain or sunshine does not have any influence, the chiller will deliver air having a constant relative humidity, regardless of ambient conditions. How does it work, where does all the water that Is in the air a humid day end up? The water will be condensated from the air when going through our cooling coil and will be removed from the cooler through a drainage. After leaving the cooling coil the air is going through a re-heating coil that makes sure that the air reaches a relative humidity that is in equilibrium with the moisture content selected. So if for example the cooler is set for corn having a moisture content of 15% the cooler knows what kind of relative humidity is required in order for the air to be in equilibrium between moisture content and relative humidity? Yes. The cooler is in fact programmed to handle 11 different types of grain each having it's own equilibrium between moisture content and relative humidity. That's impressive but how do I know what temperature to chill to? The temperature to be used depends on several factors. Generally speaking the higher the moisture content of the grain the lower the temperature needs to be in order to avoid storage problems. The length of the storage period is also of importance when selecting the temperature. There is no need to chill to a low temperature in case the grain is only to be stored for a short period of time. As a rule of thumb the temperature in the grain should be reduced to below 20°C (68°F) as soon as possible after having been placed in the silo. As soon as 20°C (68°F) has been reached, and depending on the storage period, cooling can continue until a temperature suitable for long term storage has been reached. We are often turning our grain from one bin to another for temperature control. This method works fine for us, we don't need a Grain Cooler. Turning grain is most likely one of the most common methods for controlling temperature. However, the method is very costly and not very efficient. The average cost to move grain is 0,5% of the value of the grain turned or about 1 cent/Bu. To use artificial chilled air for conditioning grain must be way too expansive? The average cost is 3-5 kWh/ton of grain being chilled. This is not high considering that once a low temperature has been reached in a mass of grain it will stay cool for months. In most cases the overall electrical bill will be reduced when using a grain cooler as the need for ambient aeration will be limited. How long will the grain remain chilled- when must it be re-chilled? Due to the fact that grain is a very good heat insulator and bad heat conductor it will remain chilled for a long period of time. It is usually several months before re-chilling is required. However, as soon as the grain temperature has increased by 3-5°C (6-9°F) we recommend re-chilling. How can I use a Grain Cooler in combination with a drier? When moving cold air through a mass of grain there will always be some drying effect. The drying effect depends on the moisture content of the grain as well as on the temperature reduction. For every 10°C (18°F) there will be a drying effect of 0,5-0,75%. By taking advantage of the drying effect when cooling it is possible to stop the drier at a higher moisture content and temperature. This will greatly increase the drying effect. What is the cooling capacity? The cooling capacity depends on a number of factors, of which the most important are: Ambient temperature Humidity of the ambient air Diameter of the silo Height of the silo Type of grain Moisture content The temperature of the grain prior to chilling The required temperature after chilling The level of purity of grain Is it necessary to insulate the duct? Yes, it is essential to insulate the duct system between the cooler and the silo. If this is not done, a certain amount of re-heating will take place in duct system, which means that the cooling capacity is reduced. Isn't it likely that condensation problems will occur during the chilling process? Normally, no. This is due to the fact that chilling takes place immediately after harvest when the ambient temperature is still high. The risk of condensation is always greater when the ambient temperature is low and the grain temperature is high. The risk of condensation during chilling can be avoided by using top roof fans.