- Frame in AISI 304/316 stainless steel, depending on requirements
- Shaftless spirals in high tensile carbon steel or AISI 304/316 stainless steel, depending on requirements
- Tank designed to increase the settling effect and prevent the risk of jamming
- The base of the tank is equipped with wear bars made of stainless steel on which the screw rests
- Inlet flow rate: 540 m³/h max (150 l/sec.)
- Separation: >= 90% of particles sized >= 0.2 mm (at nominal flow rate)
- Organic matter contents of solids at discharge: <= 3%
- Grit discharge chute
- System for bagging extracted solids: in single bags or continuous liner
- The machine can be made of stainless steel of the required type
- High efficiency washing system for reduction of the organic matter contents in the screenings
- Wastewater pre-treatment plants: municipal and industrial
- Shaftless spiral: no risk of jamming or clogging, even when handling fibrous products
- No mechanical components in contact with the product
- Reduced rotation speed
- Reduction of screenings volume of up to 40% and more, depending on the product
- Reduced investment
- No civil works required
- Reduced installation costs
- Reduced maintenance costs
- Reduced space requirements
- Reduced volume of products for disposal
Description and operation
Definitive Ecology’s compact screening and grit separation plant can be supplied with wastewater for treatment by means of a pump or by gravity feed, depending on the application.
The wastewater flows through the screen. The suspended solids are intercepted by screen: due to gradual binding of the screen the level of liquid upstream from the screen starts to rise. When the level reaches a pre-determined value the screw responsible for cleaning the screen starts to rotate. While they are being transferred out of the wastewater the screenings are washed (optional accessory) to reduce the organic matter contents. An additional screenings wash can be performed in the transport zone (optional accessory). Before being discharged, the screenings are compacted in the screw compaction zone.
Wastewater that has passed through the screen enters the settling tank, where the grit is separated. Here, the wastewater is subjected to coarse bubble aeration to optimise the grit settling process.
The grit deposited in the tank is lifted and dewatered by a shaftless screw conveyor before being discharged.
The water level in the settling tank is pre-determined to optimise grit separation.
Aeration is performed continuously with the ingress of the wastewater.
Operation of the screw conveyors and grit lifting conveyor is controlled by a timer in accordance with the quantity of grit present.
The wastewater discharged from the plant can now be transferred to the downstream treatment stages
- STU.CR = for separation of suspended solids, grit classification and washing