Evaluation of the change in the height of the dispersed material in the drying chamber by the indirect method

Abstract

Аs a result of the implementation of previously developed technologies, it is proved that a fluidized bed grain dryer is a complex multidimensional object with distributed pa-rameters and a net delay, the value of which depends on the distance of the dryer cascade from the loading shutter. In the stable mode, the dynamics model of such a complex control object can be represented in the form of a set of transfer function matrices. The structure of each of the matrices remains the same, and the parameters change depending on the placement of the cascade relative to the shutter loading. Disturbances acting on the cascades in real operating conditions should be consid-ered as two-dimensional stationary random processes of the "white noise" type, the in-tensity of which changes with the distance from the load shutter. It was also established that the changes in the height of the fluidized layer on each of the cascades are related to each other, that is, knowing the height of the fluidized layer on one of the cascades, it is possible to determine it on any other. As a result of structural identification, it was proved that there is a cross-connection between the change in the height of the fluidized bed in the cascade with the number k and the final moisture content of the material at the exit from the dryer. This made it possible to synthesize the matrix of transfer functions of the optimal observer, which evaluates the change in the height of the fluidized bed in any cascade based on the signal about the change in seed moisture at the output with the minimum error variance.