Study towards complete emptying of filter dryers (internship)

At Aspen in Oss, we contribute to the health and well-being of people all over the world. We make active pharmaceutical ingredients, the active ingredients in a medicine. Our APIs are of high quality and are used worldwide. We are committed to always offering the optimal solution for our customers. Improving our processes and ourselves is therefore really in our DNA. We think from top to bottom in solutions to issues and work together on new products. We show respect for society and the environment in everything we do.


Internship chemical engineering

Problem description

The filter dryer is emptied by pushing the product out of the equipment using the agitator. The lowest height of the agitator is limited to a few centimeters above the bottom of the filter dryer, thus a remainder (heel) stays in the equipment. The size of the heel depends on the size of the filter dryer, the lowest possible level of the agitator and the density of the crystals. Common values are 10-30 kg. For most products, this is still an economically significant amount.

In campaign or flow productions, this remainder can often be dissolved and used in the subsequent process. At some point, e.g. change-over to another product, this filter dryer heel must be removed.  Harvesting the heel requires dissolution, crystallization and isolation on a mobile filter. This typically takes 24 hours and keeps the equipment occupied, preventing the start of the next process. If the amount of remainder is much smaller, it would be economically interesting to avoid the harvesting process and immediately clean the filter dryer for use in the next process.


Design a solution to empty the filter dryers completely, leaving no significant heel.
Two possible solution directions:

  1. Equip the filter dryers to empty completely (favorite option). Example is: 3V Cogeim “Full Discharge System”, type “Xtract-1”
  2. Develop a tool to harvest the heel taking into account ARBO and safety limitations.

The ultimate goal is the omission of filter dryer heel isolation.


For more information about the content of the position please contact Marcia van Loo, E: