Case Studies QVCS04
Quadro Vac
 

CLEAN GRINDING BY VACUUM
 

Overview

Quadro recently supplied a Quadro® Comil® and Quadro Vac to the research laboratories of Merck Sharp & Dohme for use in tablet production. The units were selected after trials were carried out to compare them to the equipment commonly used by MSD - a high speed hammermill.

Quadro Vac® Solution

The main benefit claimed for the Quadro system when compared to the current system is cleaner handling of the material to be milled. The material is drawn out of a container by the vacuum created in the Quadro Vac, through the Comil, where size reduction takes place, then passes into the receiving hopper of the Quadro Vac, from where it is then discharged into the mixer’s receiving container bowl.

The Comil is fitted with a tri-clamp ferrule on the inlet and outlet, to which is connected a clear, flexible re-inforced hose. A stainless steel wand is attached to the inlet hose for the operator to drew the material out of the feed container, and the discharge hose from the Comil connects to the inlet of the Quadro Vac.

The operation of the Quadro Vac is controlled by a pneumatic control box. The operation of the various functions; fill, dump, filter back-wash, and their duration, can be controlled from this box.

The air filtration system in the Quadro Vac is very efficient. The filter cone prevents any visible air contamination from entering the process area during operation. The filter is subjected to a short pulse of compressed air during the dump of the discharge cycle so that at the end of the operation the filter is still quite clean.

  

Summary

While the important issue was the compliance with COSHH regulations, it had to be proved that the Quadro system was able to produce the same end product results as the existing system. A series of experiments were carried out to evaluate the effectiveness of the unit. These covered; size reduction of tablets to a granule for recompression in a different image, milling an active and placebo after granulation and drying, milling of a particular granulation product while wet, and milling of the same granule after drying. The Comil used in the experiments had a motor approximately 25% of the size of the unit it was replacing, but this did not materially affect its efficiency or speed operation.

Overall, the results of these experiments were successful and MSD purchased the system. Other units for Hoddesdon and their main production plant at Cramlington have subsequently been supplied.