Silo Aeration

Aeration cooling aims to maintain grain quality during storage. By maintaining low temperature and creating uniformity through the grain, mould and insects are less likely to develop. Cooling can be achieved with airflow rates of 2-3 l/s/T (litres per second per tonne).

• Aeration Hopper: Aeration cooling for elevated silos is achieved through fans installed on the hopper of the silo.Our fans have been designed and developed by Kotzur and are manufactured to the highest standards in our Toowoomba factory.
• In-floor Aeration: Aeration cooling for flat bottom silos is achieved through in-floor aeration.

Aeration drying relies on a high volume of air passing through the grain to slowly remove moisture.

Aeration drying requires higher airflow rates of 15-50l/s/T in order to effectively move drying fronts through and carry moisture out of the stored grain.

• Drying Plenum: The Kotzur drying silo uses a specially developed and patented drying cone/plenum. The air is forced into this plenum and then passes through the grain mass. The plenum design ensures the air flow is uniform through the grain mass.Different drying silo models, fan combinations and grain have varying specifications, however the typical airflow is 15-20 l/s/T or a complete change of air in the silo in as little as 25 seconds.This airflow is 10-15 times that achieved using conventional aeration. The plenum design ensures that this air flow is uniform through the grain mass and is not restricted by screens etc.
• Full-floor Aeration System: Aeration drying for flat bottom silos is achieved through full-floor aeration system. This ensures high volume of air passing through the grain.

Click here to view our range of drying silo options

The Kotzur Aeration Controller has been designed to operate the silo fans for a determined number of hours a day, when the ambient weather conditions are optimum for cooling.

The unit is equipped with a temperature and humidity sensor that reads the ambient temperature and humidity in ‘real time’. These readings are used in the controller to calculate the ‘wet bulb’ temperature, which is then compared to a ‘set point’ temperature. When the wet bulb temperature is above the set point temperature the fans will automatically turn on. Wet bulb temperature is used for this comparison as it accounts for temperature and the amount of moisture in the air.

The set point temperature is set initially at 15 degrees Celsius. This temperature is automatically adjusted to account for actual weather conditions, for example; if the temperature does not drop below 15 degrees in one day, the set point temperature is increased, likewise if it does not rise above 15 degrees it will decrease.

Aeration Modes:

• Maintenance Mode: Fans run for an average of 128 minutes a day (or 15 hours per week). If the fans are not able to run for 128 minutes a day (because the temperature is too high, for example), the amount they don’t run will be carried over to the next day, so on and so forth. This mode is used to maintain low moisture grain for long term storage.
• Cooling Mode: Fans run for an average of 214 minutes a day (or 25 hours per week). Like the maintenance mode, the hours not run will carry over to the next days. This mode is used to maintain high moisture grain for long term storage. Also used to cool dry grain in preparation for long term storage.
• Continuous Mode: Fans run continuously 24/7. The fans will turn off if the humidity is over 85%, and turn back on when it drops back below 85%.This mode is used to purge the grain mass when silo is first filled, or after fumigation. Typically, this mode would be run for 5-7 days.

A key, and often overlooked, consideration for an aeration system is to ensure that the air can exit the silo without causing back-pressure and air flow degradation.

Kotzur have two roof vents which can be fitted to silos to vent aeration air. These vents are suitable for gas sealed silos as they have a sealing system to seal the vent closed when the silo is being fumigated. Further more, with operator convenience and safety in mind, these have been designed to be operated (i.e. opened and closed) from ground level.

Kotzur can provide advice on which is the most suitable model and the number of vents required for a silo based on aeration air flow.