I spent 34 years in the salt mining industry and for that very reason is why we never used a pocketed belt. Even bucket elevators are always an issue. Salt is very hygroscopic and constantly draws moisture from the air. If you need to elevate quickly I always would recommend a sandwich type belt. But that is water under the bridge now and not helping your current situation.

The only thing I can think of that may help you out is to install a "thumper" shaft that rotates in time with each pocket. This shaft would be oblong or eccentric to thump or beat the U/S of the belt immediately after it passes around the discharge pulley. Itt may help to dislodge the material trapped in the pocket. ■

Further to Gary's comment, I always wonder at the initial plant layout. Sixteen metres lift is far, but not so far when considering the footprint versus salt accretion issue. To clean any belt it must be flat, and even then it isn't easy. Your salt will build up to the point of falling somewhere and causing aggravated corrosion. Just wait until the structure becomes rocky and then replace the expensive pocketed belt with something that you can clean better.

Beating is a basic structural gremlin which should be avoided at all costs. In other words, if the suppliers can only recommend beating as a means to clean something then use something else. Under no circumstance should you consider replacing the frighteningly expensive belt once it has worn out through beating. ■

A, An air knife, or cannons, below the belt is just another low speed resonance condition generator:

B, Pocket depth is your first problem there. You must provide a jet strong enough to displace the salt in the corners and then you must be able to contain the dust generated and finally transport the debris.

The only time to but air on a belt is to dry it after it has been washed. Air supported belts apart, where is is under the belt anyway. As so often happens nowadays the initial equipment selection was wrong and in this case the CAPEX was also out of proportion.

For further help, show us a drawing of the equipment and its surrounds. ■

Hello,

Earlier participants have already provided useful information. I add the following.

You are thinking that slow speed is a likely cause for aggravated problem. So if you like, you can try for higher speed say 1.25 mps or 1.5 mps, which are quite common for flexowell conveyors.

Such higher speed will substantially improve discharge at head pulley. Your present speed is 0.34 mps. 1.25 mps will enhance the cleaning force at discharge pulley by square of (1.25 divided by 0.34) = 13.5 i.e. more than 13 times (keeping the same diameter of discharge pulley). In addition it will also improve cleaning at beater roll, because there also the cleaning force increase will be mostly by same factor.

Ishwar G. Mulani

Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis is ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.

Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’

Advisor / Consultant for Bulk Material Handling

System & Issues.

Pune, India. Tel.: 0091 (0)20 25871916

Email: conveyor.ishwar.mulani@gmail.com

Website: www.conveyor.ishwarmulani.com ■

Take a page from Dopplemayr, which use a belt turnover to contain contaminates on the return strand.

Separately, you can calculate the impact force required to release the caked salt off the belt sidewall using basic physics. This analysis will tell you the pulse/impact energy configuration required. It takes more than a thumb suck. ■