Re: Cleaning A Conveyer
Could you explain where the material is sticking to the conveyor? To the casing or to the flight, over the full length or only inlet / outlet, etc.
If you are getting a build up on the flight, it will clearly reduce capacity but it is not clear why the conveyor should trip when you increase speed in this case. There would be a reduction in available torque if you increase speed with the same motor of course but the power consumption must be very near max if this is the problem.
If it is a build up on the flight, a ribbon flight may be beneficial by the way. It is often suggested that you run a ribbon flight a little faster than a solid flight, though if your conveyor has excess capacity or the material is cohesive you may not need to.
It would be worthwhile trying to understand the cause of the tripping before going to far with any modifications. ■
Sticking To Screw
RPD is right in that a ribbon screw is better for dealing with damp and cohesive products. Ajax has developed a special form of ribbon for such duties that resists build up around the shaft.
I will send details direct.
Tripping will be due to tip drag as the tip of the screw fight, and any material stuck to the face of the screw, shears on the boundary layer pf product that has packed in the clearance space between the flight and the casing. In circumstances where the boundary layer is firm, as with a hard packed layer or 'caked' product, this can impose a high torque proportional to the contact area, so a built-up bed on the flight face will excacabate the power problem. There are various approaches that can be taken according to the plant and screw configuration.
Lyn ■
Cleaning a conveyer
Lyn,
Flexsys, as you know a producer of rubber chemicals, has a plant in Antwerp.
After the crystalization step we separate the solid/liquid on a rotating vacuum filter. After this filter is a screw conveyer (diameter approx. 30 cm and 4 meters long) transports the wet-cake to the pelletizer/dryer.
The conveyer builts up with product (sticks to the conveyer) and this limits the capacity because if we want to increase the conveyer speed the conveyer trips.
Is there a mechanism which is able to clean the conveyer during operation?? If you E-mail me I can send you a picture of the conveyer.
Thanks in advance
Kind regards
Dick Broekhuis ■