Synchronous double-screw extruder, includes e.g. toothed wheel indicators with sensors providing signals compared for phase- or time difference, for corrective-, alarm- and shutdown action

摘要

A synchronous double-screw extruder includes e.g. toothed wheel indicators with sensors providing signals compared for phase- or time difference, for corrective-, alarm- and shutdown action. Angular differences in the angles of shaft (3a, 3b) rotation are determined continuously. An indicator (see later) of angular position is fixed to each shaft. A fixed transducer (4a, 4b) containing a sensor (5a, 5b) detects indicator angular position during rotation. The indicators are attached to screw- or drive shafts, or else to their couplings, with sensors adjacent. A unit (9) determines the difference between angles of rotation from the transducer signals, providing an output. This is connected to the controller and/or to an alarm. An Independent claim is included for the corresponding method of double screw extruder operation. Preferred features: On each shaft, there are the same number of indicators (teeth) at regular angular spacing. The sensor monitors continuously.