With current energy prices, it is important to control drying processes more effectively and precisely. This means not only measuring after the product has been dried but also controlling before the product enters the dryer.
An example of such a process is during the production of salt for the pharmaceutical industry.
If salt with an excessively high moisture content (>3.5%) enters the dryer, a blockage occurs in the dryer, resulting in the necessary downtime.
The step before the dryer is where control is now required. After various process steps, the salt is washed and passes through the centrifuge. However, moist salt causes the centrifuge’s drain holes to become clogged, reducing its dewatering capacity. This is where online moisture measurement makes a valuable contribution.
Use of the measurement:
The green line shows the moisture content of the salt. As the image shows, the moisture content will rise to 3.5%. Once this point is reached, the load on the centrifuge is reduced (black line), resulting in a lower moisture content after the centrifuge. As the drain holes become increasingly clogged, the moisture content will slowly rise again. When the 3.5% threshold is reached again, the centrifuge is switched off and rinsed, and the second centrifuge is switched on.
Since the installation of the moisture measurement and the control of the centrifuge, no excessively wet salt has been sent to the drying installation, and downtime has been prevented.
