Dear Sirs,

With entrapment of air in the cement in the loading chute or due to vibrations cuased at the belt Support Rollers, the cement fluidises and runs back if the belt is inclined. The Angle of repose of fluidised should be observed and inclination angle of the belt conveyor should always be less that that.
It is advisable not to go after the angles as mentioned in various standards or books. Since the experience is the best teacher. kindly ascertain the angle of repose of the cement in fluidised state.

One way to reduce the air entrapment from the Loading chute is to insert a bee-hive type VIBRATING INSERT so as to separate the air (which must be vented out by providing Step in the chute atthis location and connecting to the dust filter.

However re-entrapment os air still remains due to vibrations caused to the cement-mass at the belt conveyor rollers.

In any case do not increase the angle of belt inclination more than angle of repose of fluidised cement.

Mukhtar Singh
NMF Equipments and Plants pvt. Ltd.
A-146, Kalka Jee, NEW DELHI (India)