Method and apparatus for aeration of stored grain

An apparatus for controlling aeration of stored grain that is of a specified type and that is to be maintained at or near a specified desired grain moisture content, comprising:

• current ambient air temperature sensing means;
• current ambient air relative humidity level sensing means;
• current grain temperature sensing means;
• means responsive to the current ambient air temperature sensing means for calculating and storing a running average ambient temperature covering a predetermined period of time;
• means responsive to the current ambient air temperature and current ambient air relative humidity level sensing means for determing the equilibrium moisture content corresponding to said current ambient air temperature and relative humidity readings and the specified grain type;
• and
• means for calculating a daily aeration time based on the difference between the grain temperature and the running average ambient temperature;
• means for calculating the available aeration time by summing daily aeration time for each day and subtracting therefrom an amount equal to time spent performing aeration;
• and
• means for comparing the current ambient air temperature to the running average ambient temperature, for comparing said equilibrium moisture content to the desired grain moisture content and for determining if available aeration time is non-zero, said means developing a signal to initiate grain aeration only when available aeration time is non-zero and both the current ambient air temperature and said equilibrium moisture content are within predetermined acceptable ranges of the running average ambient temperature and the desired grain moisture content, respectively.

A method for controlling aeration of stored grain which is of a specified type and which is to be maintained at or near a specified desired grain moisture content comprising the steps of:

• measuring the current ambient air temperature;
• measuring the current ambient air relative humidity level;
• determining the equilibrium moisture content corresponding to said current ambient temperature and relative humidity readings and the specified grain type;
• determining an average ambient temperature;
• measuring the temperature of the grain;
• determining a daily available amount of aeration time based on the difference between the grain temperature and the running average ambient temperature and a total available amount of aeration time based on the sum of daily available aeration time less aeration time actually used;
• aerating said grain when said current ambient air temperature is within a predetermined acceptable range of said average temperature, said equilibrium moisture
• content is within a predetermined acceptable range of the desired grain moisture content and said total available amount of aeration time is not zero;
• and
• widening the acceptable range around said average ambient temperature when the total available amount of aeration time exceeds a predetermined value.

A method for controlling aeration of stored grain which is of a specified type and which is to be maintained at or near a specified desired grain moisture content comprising the steps of:

• measuring the current ambient air temperature;
• measuring the current ambient air relative humidity level;
• determining the equilibrium moisture content corresponding to said current ambient temperature and relative humidity readings and the specified grain type;
• determining an average ambient temperature;
• measuring the temperature of the grain;
• determining a daily available amount of aeration time based on the difference between the grain temperature and the running average ambient temperature and a total available amount of aeration time based on the sum of daily available aeration time less aeration time actually used;
• aerating said grain when said current ambient air temperature is within a predetermined acceptable range of said average temperature, said equilibrium moisture content is within a predetermined acceptable range of the desired grain moisture content and said total available amount of aeration time is not zero;
• and
• widening the acceptable range around said desired grain moisture content when the total available amount of aeration time exceeds a predetermined value.

A method for controlling aeration of stored grain which is to be maintained at or near a specified desired grain moisture content comprising the steps of:

• measuring the current ambient air temperature;
• measuring the current ambient air relative humidity level;
• determining the equilibrium moisture content corresponding to said current ambient temperature and relative humidity readings;
• determining an average ambient temperature;
• aerating said grain when said current ambient air temperature is within a predetermined acceptable range of said average temperature and said equilibrium moisture content is within a predetermined acceptable range of the desired grain moisture content;
• and
• widening the acceptable range around said desired grain moisture content when less than a predetermined amount of aeration has occurred, said widening of the range being unsymmetrical such that when dry weather conditions are expected to prevail the range is broader on the wet side of the desired grain moisture content and when wet weather conditions are expected to prevail the range is broader on the dry side of the desired grain moisture content.

A method for controlling aeration of stored grain which is to be maintained at or near a specified desired grain moisture content comprising the steps of:

• measuring the current ambient air temperature;
• measuring the current ambient air relative humidity level;
• determining from the specified desired grain moisture content and the current ambient temperature a desired relative humidity value that will result in the specified desired grain moisture content;
• determining an average ambient temperature;
• measuring the temperature of the grain;
• determining an available amount of aeration time for a specified interval based on the difference between the grain temperature and the average ambient temperature;
• calculating available aeration time by summing said available amount of aeration time for each specified interval and subtracting therefrom an amount equal to time spent performing aeration;
• aerating said grain only when said available aeration time is not equal to zero and when said current ambient air temperature is within a predetermined acceptable range of said average temperature and said ambient relative humidity level is within a predetermined acceptable range of the desired relative humidity value;
• and
• widening the acceptable range around said desired relative humidity value when less than a predetermined amount of aeration has occurred.