Easier maintenance and reduced space demand
Axially dividable filter baskets are optionally available, they facilitate maintenance work significantly. Massive components, such as the screw shaft and some filter elements, can now remain in the machine during inspections. Much less space and time is therefore required for maintenance. Even if non-dividable filter baskets are used, space requirements for maintenance on the installation place are now reduced to the minimum that is necessary for machine operation and inspection.
Efficient screen surface cleaning inside and outside for improved screening performance
The outer surface of the cylindrical filter baskets was previously cleaned by rotating the filter baskets along a stationary nozzle bar while the dewatering process was interrupted. The new screw press offers continuous dewatering without interruptions through a rotating washing system that rotates around the filter baskets for periodic cleaning. Dewatering degree and machine throughput are no longer influenced by interruptions or starts/stops of the washing systems. In contrast to many competitive machines the rotating washing system allows for independent cleaning of the filter surfaces of the inlet and press zone. In addition, the upper and lower filter halves can be cleaned separately so that only the contaminated filter surface sections are cleaned. Filter surface sections which have been cleaned cannot be contaminated again by wash water that runs down.This system significantly reduces the water demand for filter cleaning and additionally minimizes rewetting of the sludge cake through washing.
Reliable cleaning of the inner screen basket surfaces is just as important as cleaning of the outer surfaces. The inner surfaces are typically cleaned by a scraper that is mounted on the screw flights and wipes clear the inner filter surface as the screw shaft rotates. The efficiency of this scraping & wiping operation has direct influence on filter resistance and the water discharge velocity of the screw press. Both have an influence on dewatering degree, throughput, filtrate quality, polymer demand, and thus on the operating costs for dewatering. After extensive development and test series HUBER screw presses are now equipped with an innovative, especially designed patented scraper material which cleans the inner filter surface much better and more reliably than customary brushes and a lip seal system.
Larger screening surface for increased hydraulic throughputs
What is new is that the open filter surfaces in the filter baskets have been increased by up to 100%. The individual screen sizes are therefore able to process significantly higher hydraulic loads without placing higher loads on the filter surfaces and thus the filtrate, and without increasing polymer demand.
More efficient drives for improved performance with reduced energy costs
New drives exceed current energy efficiency standards. They save not only electricity costs, they also offer plant operators the possibility to operate their sludge dewatering unit much more flexibly due to significantly wider motor speed ranges.
Inclined installation for improved dewatering efficiency
For good reasons, the basic appearance of the press, the inclined installation, remains as it has always been. The inclined design ensures that screenings removal units can in most cases be connected without the need to place it on an additional elevation. Furthermore, the inclination of the filtrate chambers prevents sedimentation and eliminates the need for manual cleaning work. The decisive advantage of the inclined installation is improved dewatering efficiency. The separated filtrate flows off from the screen basket by gravity, against the flow direction of the press sludge. Rewetting of hydrophilic sludges through filtrate is thus reduced and the dewatering degree improved. Moreover, inclined installation facilitates especially the start-up procedure of the screw press.