PWL - Austria

We have joined hands with PWL for Chain Driven Rake Screen for Mechanical Cleaning of Waste Water. The PWL ProCat rake screen is designed as wedge wire screen. This screen is of front rake type. It combines the advantages of continuous belt screen systems with functional mechanics and an unmovable screening surface. The screen is mounted to the ProCat frame and can be dismantled. The inclination angle depending on individual requirements is between 36° (ProCat L) and 75° (ProCat I) being the reason for the high hydraulic throughput capacities of the screen.

The waste water flows through the wedge wire screen made of flow-enhanced stainless steel triangular profiles. The retained screenings are directly picked-up at the channel bottom by revolving scraper blades and, then, continuously scraped off and conveyed to the discharge area. In the discharge area there is a scraper mechanism which moves the screenings from the scraper blades without the use of brushes and spray water.

Design Feature
Within the self-supporting stainless steel frame the revolving conveyor chains as well as the units for reverse, tension and drive are arranged. The screening surface which is inclined by 36°-75° is a separate, exchangeable unit bolted to the machine frame. The complete Pro Cat incl. screen can be swiveled out of the channel.

The scraper blades are mounted to the revolving conveyor chains. If necessary, position and number of blades may be adapted according to requirements from the front side. Guiding rails avoid drifting of scraper blades.

The screen surface is continuously cleaned by the revolving scraper blades and the screenings are transported to the discharge area. The scraper mechanism – driven by the revolving conveying chains – moves the screenings from the scraper blades. Therefore, as a matter of design, carry-over of screenings to the underwater side is impossible.

Requirements:
Mechanical cleaning of municipal and industrial waste waters
Water intake from surface waters
Sludge sieving at waste water treatment plants

Fields of Application:-
Municipal and industrial WWTP
Pulp & paper
Abattoirs
Food industry
Recycling industry
Power plants

ProCat Types :-
ProCat fine screen, wedge wire openings 1-10 mm,
Wedge wire made of conical profiles,
scraper blades toothed from 3 mm upwards
ProCat coarse screen, wedge wire openings
15-50 mm, grate made of rectangular profiles,
Bars can be removed separately
ProCat in tank for above-ground installation,
inclination of scre2222W AEen 50°
ProCat in PWL MODULAR Combo units
Channel widths from 500 to 2200 mm

Technical Specification:
PWL ProCat I Fine Screen

Configuration and Process Description:
ProCat Rake Screen for mechanical waste water cleaning.
The ProCat Rake Screen combines the advantages of continuous belt screens with functional mechanics and an easily exchangeable, inclined screening surface to reach a maximum flow cross section.

The revolving conveyor chains are arranged together with the reverse, tension and drive units within the self-supporting stainless steel frame. The scraper blades are mounted to the revolving conveyor chain. If necessary, the number of blades can be changed. Thus, high rates of scraping can be realized and peak loads handled. Guiding rails avoid drifting of scraper blades.

The screen surface with one active screening area only (the medium has to pass just one “barrier”) can be replaced easily as it is a separate module. It consists of flow-enhanced triangular profiles. Therefore, this screen offers optimal hydraulic features at moderate flow velocities. The screening area is cleared continuously by the revolving scraper blades and the screenings are conveyed to the discharge area. There, it is completely discharged by a scraper mechanism which is driven by the revolving conveyor chain.

For maintenance purposes the screen can be swiveled out. The PWL ProCat Rake Screen works without use of spray water. Therefore, a water connection is not necessary. Due to its design this revolving screen is robust towards grit and rubble. The complete encapsulation guarantees for hygienic surroundings.