IED Industrieanlagen und Engineering GmbH in Frechen, Germany

Rakes and screens and are an important part of the waste water mechanical cleaning in municipal and industrial sewage treatment plants. The water flows through a more or less coarse screen. During this process, solids are separated from a liquid (water).

Reciprocating Rake Bar Screens

We call our reciprocating rake bar screens “multi-rakes”. It can be supplied in the following dimensions:

Design data:
Trough width: 600 - 3500 mm
Trough depth: up to 5000 mm
Discharge height: 800 - 2800 mm
Length of the rods: up to 2000 mm
Gap width: 5 - 50 mm
Installation angle: 70 - 80°
Running speed: 4 - 8 m/min

In the multi-rakes the wastewater flows through a slotted screen or grid with slots of a defined width. Coarse foreign materials, e.g. stones, grit or wooden pieced or other waste profucts of civilization are retained. The cleaning depends on the slot width:

Coarse rakes: > 20 mm gap width/-opening
Medium rakes: 8 - 20 mm gap width/-opening
Fine rakes: < 8 mm gap width/-opening

Thus the multi-rake has a wide application area. You can also select from a wide range of various materials for the main components, such as grizzly bars, strippers, wipers, housing, discharge, drive, etc.

Sieve-bent Screens

Our static screens are also called sieve-bent screens. They are ideally suitable for separation of the finest, especially fibrous solids from the wastewater and process water. The flowing-in wastewater is accelerated. It flows evenly and transversally to the gap or slot along the screen surface and into the sieve body. The fine gaps prevent penetrating of coarse solids. The latter are pushed down by the after-running waters onto the curved filter plate. Since the filter material falls onto the screen surface by itself, you usually do not need any cleaning devices.

Drum Screens

Drum screens are slotted drums which are charged externally. They are used for separation and discharge of both coarse and fine solids from the wastewater. Their main areas of application are industrial wastewater cleaning plants.

With drum screens, you can achieve an effective solid-liquid separation, at sieve gap widths from 0.25 to 2.5 mm. During continuous and effective cleaning, the retained solids are scraped off from the drum by a wiper blade and dumped. The drum screen can be flushed continuously or intermittingly. It consists of the following parts:

Screenings Presses

Screenings presses are used for dewatering and reduction of the screenings volume previously withdrawn by means of coarse and fine rakes or screens. The screenings fall into the feed trough and is then conveyed by a screw conveyor to a discharge pipe. Then the conveyed screenings are pressed. Optionally, they can also be washed before pressing. The screw conveyor rotates above the screen bottom so that the escaping water can drain through it. Then the pressed and drained screenings are conveyed into a container through the discharge pipe.