High Density Cleaners

The high density cleaner is installed after the pulping phase and is used for a continuous elimination of contaminants such as stones, woods, metallic and plastic parts contained in the pulp, from waste paper or cellulose at consistency between 2-6% ; all this with the purpose to protect the machine installed in the successive working phases.High Density Cleaners

The pulp slurry from the dump chest is fed to three parallel high density cleaners at a consistency of 3.5 percent. The accepted pulp from the high density cleaners flows on directly to the primary coarse screen. The rejects such as staples and paperclips, are trapped in the reject chambers where water is injected to separate fiber from rejects to improve system yield. Timers periodically isolate the reject chambers and open dump valves to purge the reject chamber of rejects. The end of the time cycle closes the dump valves and opens the chamber to the cleaner for reject collection once again. The purpose of high density cleaners is to protect the pressure screens from large, heavy debris not removed by the detrashing system. Feed pressure to the cleaners is fixed by the feed pump. The pressure drop across the cleaner is fixed. The pressure of the accepts pipe is automatically controlled to maintain feed pressure to the primary coarse screens.