Control of laboratory grinder, for processing sample materials for analysis, involves measuring motor power for empty beaker followed by timed measurements during grinding, to give energy consumption

摘要

To control a grinding mill with a three-phase motor and frequency converter, a value for the motor power is taken over a given time span and passed to a control unit to be multiplied by the energy consumed, and the readings are added to give the consumption. The initial reading is for use with an unfilled beaker to give the comparative value. Further readings are taken with a filled beaker for comparison with the initial zero level. To control a grinding mill with a three-phase motor and frequency converter, and especially in a laboratory, a value for the motor power is taken over a given time span and passed to a control unit to be multiplied by the energy consumed, and the readings are added to give the consumption. The initial reading is for use with an unfilled beaker to give the comparative value. Further readings are taken with a filled beaker for comparison with the initial zero level. The first step can be with an empty beaker, or a beaker containing the grinding balls but without the material for grinding.