Skip to main content

Menzel supplies replacement motor

Published by
World Cement,

In 2015, a Senegalese cement manufacturer had to replace their old coal mill for a major inspection process, and install a technically and mechanically compatible replacement motor.

Menzel Elektromotoren was tasked with this assignment.

The motor provides the plant with finely ground coal dust to meet its energy needs and is operated in a hazardous area classified as zone 22. Particles of conductive dust left on slip rings and brushes could cause sparks that lead to an explosion, so the motor required a design that would prevent dust ingress during all operating stages.

Menzel engineered a rugged unit with IP65 ingress protection. Because a squirrel-cage motor requires a high starting current and has a lower starting torque, a slip ring motor was chosen. A special motor construction was then devised for the application: the system features special terminal boxes for the stator and rotor, a non-magnetic cable entry plate, and hazardous area terminal clamps for the auxiliary terminal boxes. In addition, the motor housing is slightly larger to ensure the operating temperature does not exceed +125°C. Additional fixing points between the radiator and housing facilitate tightening of the sealing in-between. The engineers also reinforced Menzel's standard viewing windows for the slip ring chamber with bolted covers and plexiglass to ensure proper tightness.

hese measures meant that the replacement motor received a Ex II 3D Ex tc IIIB T125°C Dc explosion protection marking and performs reliably in zone 22.

Read the article online at:

You might also like


Optimisation 2020

Optimisation 2020 provides a unique online forum for cement industry professionals to hear first-hand from experts through a series of exclusive presentations from cement producers and industry experts.

Find out more and register for the series »



World Cement Spotlight with Rockwell Automation

World Cement Editor, David Bizley, sat down with Michael Tay, Advanced Analytics Product Manager at Rockwell Automation to discuss his recent article in World Cement.

Entitled ‘Smooth Sailing’, this article explains how machine learning can help save energy, reduce downtime and predict equipment failures, thus enabling the smooth running of cement plant operations.

Watch the interview now »


Embed article link: (copy the HTML code below):