Resolving Non Target Solvent Attack Dynamics in High Temperature Cellulosic Separations
Maintaining solvent moisture at 13.0 percent and temperatures below 108°C prevents non-target synthetic polymer breakdown during cellulosic extraction.
Rotary Pressure Drum Filter
Separation Apparatus
Continuous filtration machinery utilizes a rotating cylinder enclosed within a pressurized housing to separate suspended solids from liquid slurry flows under positive pressure. The rotary pressure drum filter is employed in textile fiber mills to separate hemicellulose or wash pulp after chemical treatment. This system maintains a pressurized environment to prevent liquid flashing and ensure a high filtration rate.
Cake Washing
Displacement washing of the collected solids occurs continuously as the drum rotates through the pressurized slurry zone. Using the rotary pressure drum filter allows mills to achieve high wash displacement with minimal fresh water usage. This minimizes the volume of dilute liquor that must be sent to the evaporator stage.
Process Integration
Consistent pulp moisture is achieved through continuous pressurized dewatering. Applying the rotary pressure drum filter ensures a stable feed of purified cellulose to the downstream dissolving or xanthation reactors.
Mechanical Operation
Automated scraper blades or discharge rolls remove the concentrated filter cake from the drum surface without stopping the rotation or losing pressure. Modern rotary pressure drum filter designs include variable-speed drum drives and adjustable pressure controls to handle fluctuating slurry consistencies from the pulp mill. This continuous operation eliminates batch delays and ensures that purified cellulose is delivered to the spinning line at a uniform rate.