The Lenzing CakeFil is a fully automatic self-cleaning tubular pressure filtration system, otherwise known as a candle filter. This sophisticated filtration technology is centered around cake building, that is, a cake of solid contaminants in the liquid stream builds on each of the porous cake support cloths that cover the full length of the candle elements. This results in the cakes themselves becoming the filter media through which the clean liquid (filtrate) passes. Since the cake`s solids are size graduated, that is, the largest particles are in contact with the cloth and smaller ones are further away, very fine filtration is possible. Specifically, 1 micron filtration is achievable without filter aid and 0.5 microns is possible with filter aid. Captured solids can either retained or discarded as waste. The waste discharge can either be "dry to the touch" (around 40-50 % moisture content) following the automatic blowdown step or in pumpable wet slurry form. An automatic cake wasting step (prior to cake blowdown step) is also possible in the case of the dry cake discharge design. The sophisticated design of the filter candles used by Lenzing ensures uniform cake structure, thus fine filtration, as well as efficient cake discharge.
Precoat Filtration - Advantages
The Lenzing ScrapeFil uses a cylindrical wedge wire screen to remove solid contaminants. The solids are captured on the outside surface of the screen as a result of an outside-to-inside flow of fluid. The wedge wire screen continuously rotates and is in contact with one single spring actuated scraper blade which serves to scrape off captured from outside surface of the screen, such that they fall into the conical sump of the housing. The geometric profile of the wedge wire strips that are welded together to form the screen dictate the micron rating of the screen as well as ist cleaning efficiency. A valve located at the bottom of the housing is actuated on a regular interval (timed) basis to discharge solids that have been removed by the scraper blade.Cake Filtration - Advantages
The Lenzing HisoFil filter cartridge is a unique pleated cartridge that was developed to filter liquids containing high solid loads. The HisoFil cartridge was designed with the benefits of flow velocity reduction in mind. At these low flow velocities, even small or soft solid particles can form a filter cake on the high surface area pleated media, contributing to high dirt holding capacity. The HisoFil cartridge design results in reduced cartridge replacement intervals as well as lower filtration costs. The best HisoFil cartridge applications include those in which labor costs associated with cartridge changeout are significant and operator safety is deemed to be critical.