Gas tight filters are currently used for many pharmaceuticals, both intermediate and final, as well as fine chemicals, bio-products, solvent-processed foodstuffs, solvent wetted organic solids, and pyrophoric materials. With over 120 production scale units installed worldwide, Larox is the world leader in solvent-based vacuum belt filtration with the Pannevis GT filter.
Pannevis GT filters offer all the advantages of the standard RT filter including co- or counter-current washing, reflux washing, vibration, all forms of mechanical compression and either hot gas or infra-red drying. They can be configured in many different combinations of the above options for multi-step processing exactly as the standard RT filters.
The housing is normally operated with a few millimeters of water gauge over-pressure inside. The nitrogen is pulled from the housing during the vacuum stroke by the vacuum pump, where the condensate is removed, and the “dry” nitrogen is then returned to the housing. A very small make-up of nitrogen is required to compensate for nitrogen exiting with the wet filter cake.
The floor and roof of the housing are rounded while the sidewalls are flat. This ensures easy cleaning. Hinged windows in the sides and lights in the roof ensure complete visibility. The windows also provide local access within the housing. Clean-in-place (CIP) is a standard option and the standard filter is designed for sanitary operation as all dead spots are eliminated, windows and nozzles are angled to drain back into the housing and internal surfaces can easily be polished to a specified level.
As with all RT filters, the RT-GT filter is extremely reliable and maintenance is simple. All the major maintenance items including the cloth drive and bearings, air cylinders and cloth tracking actuators are mounted outside the housing, so it is not necessary to access the inside of the filter for normal scheduled maintenance. Where internal access is required for things such as cloth change or replacement of cloth tracking rollers, access is via the windows or large diameter man-ways in the filter housing or via removable housing end panels.