Longitudinal & Circular Scrapers

Grit channel scraper


UWA grit channel scrapers can be installed in rectangular basins/tanks built in accordance with the DIN standard 19551. These units are equipped with rail tracks. Alternatively, they can also be fitted with or without a positive drive system in case of a rail-free operation. The high standard of UWA technologies guarantees an absolutely synchronous run of these systems and a reliable winter operation.

The grit channel scrapers can optionally be equipped with blade or suction scrapers.

An optimal scraping result can be achieved by height-adjustable grit and scum blades or in case of suction scrapers by controlling the sand pump. The solid structure optionally made of stainless steel, aluminium or galvanised steel ensures a high corrosion protection and thus a maximum service life of the plant.

All components installed in this plant comply with the high requirements of DIN 19569, especially with regard to the specific load and material requirements.

The running speed fulfils these regulations as well. The running gear is designed to withstand the highest stresses. Furthermore, it ensures a low maintenance rate and a trouble-free operation.

Longitudinal scrapers


UWA has taken on the challenge of a constantly improving technology in terms of the mechanical wastewater/ sewage treatment. Scraper systems are constructed in line with DIN 19551 part 3 and according to the different requirements. Of course, the design of our equipment is state-of-the-art. The trendsetting construction design is suitable for all individual solutions. All UWA scrapers are equipped with an automatic floating solid and sediment scraper blade.

The scrapers can be fitted with a positive drive system via rails and racks in order to ensure a reliable operation in the winter season.

The most significant feature of UWA plants is a high economic efficiency thanks to a mature and sophisticated technology and a low maintenance rate. UWA also designs automatic spraying and injection systems with movable spraying fittings and pumps (type LW) for storm water tanks. Of course, we would be pleased to inform you in terms of the individual use of our components.

The scrapers designed as a solid structure bridge are either made of aluminium, stainless steel or galvanised steel.


Circular scrapers can either be equipped with a blade scraper including a decentralised RS pump unit or with a suction scraper including a pump unit on the bridge. The round secondary clarifier with its horizontal bottom plate and suction scrapers is without doubt the most economical solution in terms of wastewater/ sewage treatment.

Thanks to many years of experience in engineering and production of circular scrapers, combined with constant innovations, UWA is in the position to offer mechanical technologies with decisive advantages:

  • Optimal separation performance
  • Immediate sludge recirculation
  • Higher content of oxygen of RS
  • No sludge lifting

The scraper bridge consists of a rugged solid structure optionally made of aluminium, stainless steel or galvanised steel. It includes safety grids. A running gear including a powerful drive motor is adapted to the radius of the tank and mounted on the scraper. Malfunctions due to obstacles on the run track of the tank wall are avoided by means of wipe-off rims. The electronic equipment of all UWA plants is designed state-of-the-art and according to the protection class IP 55. A weatherproof control cabinet including clearly arranged operation elements as well as a control system with touch panel is mounted on the scraper bridge.

A reliable winter operation is realised by means of positive drives via racks/rails.

Rail track covers

UWA Fahrbahnabdeckungen

The heated rail track covers designed by UWA ensure a reliable winter operation in terms of longitudinal scrapers and circular scrapers. The specific arrangement and position of the heating cables enables a direct energy transmission to the rail track cover as well as a trouble-free replacement of the heating cables at all seasons. A lower electric capacity is guaranteed thanks to the heat-insulated arrangement of the heating cables to the concrete and the specific registration of the track temperature. The operational costs are reduced to a minimum by using the heating only in case of need. The rail track cover is designed as a centred, slightly raised system in order to ensure a trouble-free drain-off of rain water and snow.

The cover is preferably made of stainless steel.

Positive drive for longitudinal and circular scrapers

Zwangsantrieb für Längs- und Rundräumer

Our positive drives working via rail and rack systems enable a reliable winter operation. Heated rail track covers, heater blowers or de-icing systems can thus be omitted whereas the low operating costs (e.g. no electricity costs) guarantee a high efficiency.

The scrapers run on rail track wheels driven by a gear drive. The rails as well as the gear racks are made of hot-dip galvanised steel and are manufactured in a circular design in order to mount them on the circular tanks. This system can optionally be delivered with running wheels if rail tracks are not required.

Our scrapers feature several advantages:

  • Absolute reliability at all seasons and all weather conditions
  • Additional costs for heating purposes can be avoided.
  • No restoration costs for the tank heads.
  • No wear of the running wheels.

Besides new plants, we also carry out retrofitting services on existing plants e.g. installation of a positive drive system. 

Mature technology

Komplette Räumeranlagen auf neuestem technischen Stand,
für individuelle Problemlösungen.

UWA Ausgereifte Technik

Complete state-of-the-art scrapers for individual problem solutions

UWA supplies:

  • Scrapers for every need
  • Technical standard according to the highest requirements
  • Maximisation of construction and process technology
  • All products from one source

Project engineering and execution – the work for specialists.

Our main task as a company for civil and plant engineering, in combination with construction and process engineering, is to guarantee a complete and absolutely economical solution concerning technical and functional aspects. This is what we stand for!

UWA stands for a profound knowledge and many years of experience in the construction of industrial and municipal wastewater/ sewage treatment plants. We solve all wastewater/ sewage problems in cooperation with our local and global partners.