Combination screen: 1 drive – 2 cleaning stages
Sometimes 2 screens are needed: For example, when fine screening is required and at the same time a relatively high coarse material load is present. In such cases, a combined solution in the form of two-stage screening is recommended. A coarse screen is installed upstream of the fine screen. The raw wastewater is first passed through an integrated mechanical pre-treatment system. With the 1st coarse screen the contec screen separates the larger impurities. The wastewater pretreated in this way then reaches the 2nd screening stage. A finer perforated screen is installed there for the separation of smaller solids.
Alternatively, it is of course also possible to operate two separate, spatially separated machines. In most cases, integration in a single machine makes more sense.
Design and adjustment
The design of such a combination screen is based on the criteria of the fine screen. The coarse screen is adjusted according to your individual specifications, which are based on empirical values. Combination screens are a self-contained wastewater treatment systems. Such units consist of
- 1 coarse screen,
- 1 fine screen,
- 1 screenings press or screenings washing press,
- 1 container.
nrw contec combination screens are particularly suitable for sewage treatment plants where coarse material separation must be installed upstream of a fine screen.
Effective & economical
A brilliant result in every respect: a nrw contec screen reliably removes floating, sinking, suspended and fibrous matter. Extremely low-maintenance, it also requires little cleaning water and energy.
Numerous sewage plant operators and industrial companies trust the stable, long-lasting screen.
- High degree of separation of screenings
- Low space requirement
- Little cleaning water
- Extremely low maintenance
- Designed for high durability
- Economical thanks to low drive power.
Cleaner & conditioner
Areas of application wastewater treatment plant
- Mechanical waste water pre-treatment
- Pre-cleaning for membrane sewage treatment plants
Fields of industrial application
- Wastewater treatment
- The waste water reaches the semicircular perforated screen plate, which retains screenings.
- The screenings are conveyed by brushes into the lateral screenings discharge.
- The water cleaned by the 1st screen flows into the perforated screen of the 2nd screen.
- A simple process for an exceptionally high degree of separation.
Basic equipment of the nrw contec combination screen:
Sophisticated, robust and durable
Drive: Made in Germany
The brush cross in a nrw contec screen copes very well with only approx. 2 revolutions per minute. Driven by energy-efficient and highly reliable gear motors made in Germany.
Variable: Cleaning brushes
The polypropylene brushes used in the screen achieve a service life of several years. Due to their length and arrangement, they are extremely resistant even to abrasive Screenings.
To compensate for wear, you can simply readjust the brushes. In normal operation, the brushes achieve service lives of several years.
Smaller systems are equipped with a hood.
Larger units have a hood, door and protective grille.
Options for the nrw contec combination screen
The Infeed of the nrw contec screening plant is located on a front side. In the standard system you can choose
- from inlet flanges of different sizes according to DIN or ANSI standard.
- from special constructions according to your requirements.
Every drain installation is different. nrw contec screening systems adapt.
So the purified water runs ...
- freely downwards into a tank/ container,
- via an open channel into downstream plant components,
- into a catch basin with connected piping into downstream plant components.
Select the screen that matches the screenings ...
- ultra-fine screen: opening 0.8 - 2 mm
- Fine screen: opening 2 - 4 mm
- Coarse screen: opening 4 - 16 mm
- Stainless steel 1.4301
- Stainless steel 1.4571
- Special materials, for example 1.4462 Duplex (extremely corrosion-resistant)
If, for any reason, a nrw contec screen should experience a hydraulic overload, it is protected by
- an overflow pipe.
For example, if the screen is installed to protect an MBR system.
- a box as a bypass.
An overflow that allows wastewater to pass through the screen untreated in the event of an overload.
Accessories for the nrw contec combination screen
Discharge via screening chute
The simplest ejection solution.
Via the screenings chute, the solids are discharged directly into a container.
The chute in the form of a flat channel can be open, covered or equipped with heating.
Discharge via screenings conveyor
For the removal of separated screenings.
A screenings conveyor (spiral conveyor / screw conveyor) installed at the screenings discharge conveys the screenings horizontally/sideways.
screenings press discharge
For weight and volume reduction of the screenings.
The screenings press is installed directly at the screenings discharge.
The screenings press or "screw press" conveys the separated screenings laterally into the pressing zone, the perforated plate pipe, by means of an integrated screw conveyor.
Through a flap at the end of the pressing zone, the press generates a counterpressure. In this way, the soft, waterlogged screenings are virtually wrung out or compacted.
As the water drains through the perforated screen tube of the pressing zone, the pressed screenings push out like a sausage.
Discharge via a screenings washing press
For the removal of still adhering faecal residues.
Similar to the screenings press, the screenings washing press is installed directly on the nrw contec screen. Or it is at the end of a screenings conveyor.
The screenings washing press also presses the water out of the screenings. In addition, however, it washes out the screenings. This is done via forward and reverse rotations, while wash water is injected via additional solenoid valves.
This washes away most of the adhering fecal matter. And flow back via a pipeline into the inlet shaft through which the screen is fed.
For hygienic collection and storage of the separated screenings.
Undesirable: Odour nuisance due to unpleasant smells or vermin "hatching" in the screenings.
A sagging device provides a remedy here. This also discourages animals from searching for food in screenings and spreading it over a large area.
For winter operation
Controlled heating system for winter operation in various heating capacities.
With outlet flange according to DIN or ANSI.
For cleaning the back of the perforated screen plates.
Underframes for adaptation to special installation conditions.
Detection via sensor in emergency overflow.
Container with or without drainage.
With flange according to DIN/ANSI for the extraction of unpleasant odours.
Control incl. safety devices as standard or according to your specification.
Manual or automatic lubrication devices for the shaft bearings.
More details about the nrw contec screen?
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Please write to us if you would like more information or have any questions. We look forward to hearing from you.
Stefan Fischer and Daniel Durain