The HUBER RakeMax® Multi-Rake Bar Screen for preliminary mechanical wastewater treatment was developed by HUBER in 2003 and presented to the public for the first time at IFAT 2005. Due to its versatility the RakeMax® has since very well proven its efficiency and become firmly established in the global wastewater technology market.
On the basis of the successful RakeMax®, another new screen type for headworks has been developed in the course of continuous further development, the RakeMax-hf®. It is a L-shaped multi-rake bar screen and like the RakeMax® screen belongs to the MAX family of HUBER screens. This screen has a flat and therefore hydraulically advantageous bottom section that transitions into a steep conveying section. This combines the benefits of the well proven RakeMax®, reliable solids separation and high screenings discharge capacity, with a low headloss due to a big effective screen rake surface. Material removal from the screen starts right at the bar rack mounted flat to the channel bottom so that any accumulation of disturbing material is eliminated. The cleaning elements, attached to the chain system, can easily be adjusted to different requirements. This is especially favourable for high solids loads. Depending on the bar spacing, the bar rack design is either a flow-optimising bar or non-blocking wedge wire profile. Both ends of the cleaning elements are connected to drive chains. Each chain is driven by a sprocket on a common shaft and a flange mounted gear motor.
At the end of the bar rack cleaning cycle the cleaning elements are positively cleaned by a pivoted comb which reliably discharges the removed screenings into a downstream transport or disposal unit. The easy to access and maintain drive unit is installed above the channel. Due to the screen’s compact design its height above floor is very low.
Especially in existing screening plants minimum requirements on solids retention in the inlet are not reliably met so that the passage opening at the bar rack must be reduced, frequently with the result of growing hydraulic loads. These conditions make it inevitably necessary to provide for a bigger hydraulic passage area, and this normally means that the size of the existing channel has to be extended or even a new building erected for the screen, with the result of high construction costs.
With the new L-shaped RakeMax-hf® screen HUBER offers another type of inlet screen in order to be able to better meet customer requirements in terms of specific constructional and hydraulic site conditions and reduce investment and operating costs.