Patent ID: 8726535

Claim:
A method of drying of a product in a drying bin from an initial moisture content to a final moisture content with heated air and drying pressure comprising: a. deriving a correlation between a target exhaust temperature rate and a target drying rate for the product; b. during a first portion of a drying period, assigning a set point for the target exhaust temperature rate by measuring actual exhaust temperature and determining when exhaust temperature is stabilized; c. for a second portion of the drying period, measuring actual exhaust temperature, comparing measured exhaust temperature to the target exhaust temperature rate at or near the measurement time and adjusting heated air and/or drying pressure based on the comparison to influence measured exhaust temperature to follow the target exhaust temperature rate; and d. estimating product moisture content for a current time during the second portion of the drying period by: i. plotting the target exhaust temperature rate and measured exhaust temperature, each as a function of a same range of exhaust temperature relative to a same range of drying time; ii. determining an index of target energy needed to dry the product to the current time by integrating the exhaust temperature rate function between the set point time and the current time; iii. determining an index of current energy used to dry the product to the current time by integrating the exhaust temperature rate function between the set point time and the current time; iv. comparing the index of target energy and the index of current energy; v. fitting the index of current energy under the target exhaust temperature rate function to produce an index of equivalent energy; vi. deriving an equivalent accumulated drying time for the equivalent energy by accounting for any offset of the index of equivalent energy from the index of target energy along an ideal energy function; and vii. calculating estimated current product moisture by: (initial product moisture)−(equivalent drying time/target drying rate).