Low speed shut down method for high temperature hammer mills

Abstract

Low speed shutdown apparatus for a high temperature hammer mill having a relatively high speed drive motor connected to the hammer mill drive shaft includes a low speed, high torque shutdown drive motor and a drive belt for connecting the low speed shutdown motor to the hammer mill shaft in place of the high speed drive motor. Preferably both the high speed drive motor and the low speed shutdown motor are connected to the hammer mill shaft through electrically controlled clutches, an electrical control being provided for disengaging the high speed drive motor in the event of a shutdown situation in which the hammer mill is shutdown while loaded with hot material and for engaging the low speed motor with the shaft to keep the shaft turning so as to prevent or substantially eliminate warping of the shaft due to the high temperature in the mill while the mill cools down. The low speed shutdown motor is reversible to enable the driving of the hammer mill shaft in either rotational direction selected by an operator. A corresponding method for shutting down a high temperature hammer mill is provided.