ERR Stainless Steel Circular Scrapers are characterized by the consequent preference for stainless steel over conventional materials.
The combination of stainless steel with the especially selected and used plastic components leads to an overall scraper systems with minimal maintenance, the least possible wear and further more therefore also with a longer than average life span.
Stiff and lightweight stainless steel truss bridges
The frameworks of the circular scraper system are made of tight welded stainless steel hollow profiles.
Teh bridges therefore are characterized by especially great resistance to both bending and torsion in combination with little overall weight and minimum area exposed to wind.
The whole bridge is completely immerdes pickled and finally passivated ensuring corrosion protection at the best.
Stainless steel antislip safety gratings
For the operating plattforms and the access ladders only lightweight stainless steel safety gratings are used.
Despite the light weight the gratings have exceptional load rating and the gratings’ edges are bent up working as integrated guard rails for ankles.
Maintenance-free lightweight scraper blades
The scraper blades typically are formed as one continuous logarithmic spiral and are made of tight welded stainless steel hollow profile frameworks having planking made of plastic material. Adjustable Polyurethane wear strips work towards the tank’s bottom.
The Goverall weight of the scraper blades is nearly compensated by the buoyancy of the hollow profile framework. Therefore the the self-adjusting twin wheels of the scraper blades have to carry only very little load at all.
Central bearings free of undesirable constraining forces
The truss bridges with the stiff stainless steel frameworks are fixed to maintenance-free centreal bearings with elastic intermediate Polyurethane bedding plates.
The elastic bedding plates ensure that no undesirable constraining forces created e.g. by unevenness of the runways neither work on the central bearings nor on the truss bridges.
Corrosion resistant stainless steel chassis
In combination with RRA Antislip Driving Belts the scrapers can be equipped with completely corrosion resistant carrying wheels. Not only the rims, but also the shafts and the even the wheel bearing are completely made of stainless steel.
Due to the lightweight design of the truss bridges the specific wheel loads are extremely low. The additional use of elastic solid rubber tyres for all carrying wheels enables lowest possible runway surface pressure.
Patented, all-weather drive unit RRA Friction Wheel Drive
The circular scraper system is preferably driven by the patented RRA Friction Wheel Drive.
The torque necessary for the rotation of the scraper bridge is created at the vertical tank wall by pressing the gear motor and the drive wheel to the inside or outside of the tank wall.
At ERR Stainless Steel Circular Scrapers the drive motors typically only have a power rating of 0,25kW.
Patented, fully automatic scum removal system SSR Screw-conveyor Scum Remover
For the removal of scum and foam typically the patented system SSR Screw-conveyor Scum Removers is installed.
The SSR system allows for an effective and fully automatic scum removal at water level flucutations up to 500mm and therefore also at structural height differences e.g. caused by unevenness of the scraper system’s runway.