Please assist me with the following: I want to improve the level control of a hopper used for holding a powdered material. Feed flow into hopper is such that one conveyor (1) discharges from silo then feeds another conveyor (2) then a bucket elevator takes material to the hopper.

At present, control is such that when hopper level drops chain conveyor (1) must start or increase speed to fill up the hopper and stop. It is controlled via VSD/VFD. The challenge is that sometimes the level fluctuates so much that conveyor (1) VSD seems not to cope with the change.

Your assistance is very important

 

Check your filtering time or your ramp down/up time.

 

You may program the VFD if option is provided for two speeds operation. Which is usually given in most of the VFDs.

Suppose When Hopper is empty VFD start with slower V1 speed. After some time delay, The VFD go to faster V2 speed if Hopper Full sensor do not give command.

VFD stops after Hopper full sensor gives the command whether VFD is running for V1 or V2 speed.

You may introduce one more Hopper full and empty sensing inputs to VFD for more intelligent control.