Screening

Rakes are mechanical preliminary cleaning systems, while the water is passed through a filter surface and the screenings separated and dewatered. Depending on the gap or hole diameter coarse and fine screens are differentiated.

Transport of screenings either with conveyor or direct discharge to a wash press, whose job is to wash the organics and the dehydration and compression.

The Package Inlet Work is a combination of screening with the subsequent step of the grit chamber in a compact system design.

Multi Rake Screen

The waste water flows through bars made of stainless steel, while contaminants are held back. Solid matter is picked up directly at the bottom of the channel without the need for a base step. The cleaning elements are fixed between two chains and are designed with teeth for the best cleaning of the screen. The screenings can be discharged into containers, washing compactors, screw conveyors, conveyor belts etc.

Advantages and Specification

• Suitable for very deep channels and pump stations
• Slot opening starting from 2mm
• Fitted with anti-jamming and overload devices
• high removal capacity due to the multiple rake
• Possibility of pivoting

Climber Screen

The waste water flows through a grid rack of steel or stainless steel which retains contamination of products. The cleaning carriage is moved through a rack and pinion drive system. The path and angle of the cleaning rake are controlled by side rollers running in a guide track. At the lower turning point, the rake protrudes through the grid, so that screenings cannot get stuck. Solid matter is directly picked up by a special cleaning rake at the channel bottom; there is no need for a discontinuity in the channel bottom. Screenings are pushed into a container, screenings press, screw container, belt conveyor etc. via a pivoting stripper. The screen can be mounted vertically in flumes and can be arranged as a forward flow or reverse flow unit.

Advantages and Specification

• robust construction
• no drive elements in water
• easy to maintain

Grab Screen

The waste water flows through a grating screen made of steel or stainless steel, while contaminants are held back. Solid matter is picked up by our special grab directly at the bottom of the channel without the need for a base step. The teeth of the grab act between the bars of the screen thus preventing jamming of the screenings. A pivoting scraper discharges the screenings into a container, wash compactor, screw conveyor, conveyor belt etc. Opening and closing of the shovel is achieved by means of a slack rope weight.

Advantages and Specification

• suitable for deep pump stations and water intake
• all works can be done from floor level
• high reliability through robust construction
• no driving parts in contact with water

Perforated Belt Screen

The waste water flows through perforated filter elements made of stainless steel, while contaminants are held back. Solid matter is picked up directly at the bottom of the channel without necessarily requiring a base step. The filter elements form a continuous filter belt which is cleaned by a brush at the upper deflection point. The cleaning process is assisted by a series of jets working in proportion to the screenings load. Tines located on every 5th screening element prevent build-up of rolling matter in front of the screen and ensure that large matter is removed.

As a result of the half-round shape of the filter elements and the arrangement of the cleaning brush at the upper deflection point, the distance between the brush and the filter element remains constant for optimized cleaning.

Tests have shown that the screens with perforation of 6 mm approximately filter out double the amount of screenings as stage screens with 6 mm gap size due to the built up screenings carpet. The screenings retention figure of a screen with 6 mm holes is of the order of 76%.

Advantages and Specification

• best capture rate > 75 %
• filter size starting from 2mm
• highest cleaning frequency through screenings carpet
• suitable for pretreatment of MBR systems
• pivoting possible

Step Screen

Step Screens are "stepping" type of screening systems for separating suspended solids from effluent, sewage or process flows. They are designed to handle large flow rates with small head loss, low energy consumption and minimal maintenance. Primarily intended for sewage inlet works, these screens are also applied into many industrial process applications. The most common arrangement is gravity channel (concrete) flow, but these may also be tank mounted for pumped or gravity flow.

Advantages and Specification

• no chains or wheels in water
• long life bearings with automatic greasing
• no need for back wash
• maintenance free

Inclined Drum Screen

Screw screen compactor with reinforced shaftless spiral for channels. This is a combined machine to separate the solid from the liquid and to lift, compact and dewater the screenings before the discharge.

Advantages and Specification

• suitable for tank or channel installation
• screening, conveying and compacting of screenings in one machine
• with perforation or wedge, pitchs 0.2 - 10 mm
• capacity up to 1000 m³/h depending on the model, the effluent and the screen mesh

Micro Filter Screen

The Micro Filter Screen can relieve primary treatment burden at municipal and industrial wastewater treatment plants in a very small footprint, saving major infrastructure, investment and space. Screenings dewatering and odor containment are integrated parts of the machine.

Features:

• removes organic and inorganic solids as fine as 15 -30 micron [µm]
• removes up to 40-70% TSS and 30% BOD.

Vertical Screw Screen

This is a screw screen press for vertical installation as a combined machine to separate the solid from the liquid and to lift the screenings before the discharge.

This machine is best suitable for screening in pump stations and manholes.

Advantages and Specification

• for pipe size 200 - 700 mm dia
• small foot print
• Screen mesh 0.25 - 10 mm with wedge wires or holes
• Discharge of grease in large quantities presents no problem.
• Capacity up to 1000 m3/h

Basket Screen

The basket screen is excellent for installation in pumping stations and manholes. It is based on the design of coarse bar screens.

The basket screen is raised and lowered in the shaft via an electric hoist and guided by rails. The rails are curved in the upper area which facilitates emptying of the basket over the container. Final emptying is carried out by hand with a rake.

The screen basket is constructed of stainless steel sections with a gap of 10 - 40 mm.
When the screen basket is raised, the feed is automatically blocked by a drop screen so that no screenings can get into the outlet channel while the basket is being emptied.

Advantages and Specification

• Suitable for deep wells, small space requirement
• The screen allows the passage of grit without malfunctioning.
• Screenings conveyed positively to the discharge point.
• Excellent cost/performance ratio and easy maintenance

Storm Water Screen

The wastewater flows through perforated filter elements made of stainless steel, whilst contaminants are held back. The water can flow through both sides of the screen. The filter elements form a continuous filter belt, which is cleaned by a brush at the upper deflection point. The screenings will be discharged back to the wastewater. Sealing at the sides prevents solids from circumventing the filter. The filter elements can be individually and quickly exchanged.

Advantages and Specification

• Waste water pre-treatment / fine screening
• Sea water treatment
• Rainwater tank overflow and storage channel screening
• Typical use for bottom manhole

Washing Compactor

The wash compactor is to be used for washing out, de-watering and compacting screenings. The press water outlet to the channel is located immediately following the screen.

The washing compactor is synonymous with hygienic and efficient handling of screenings. Waste disposal is a cost factor at every installation - wet screenings are heavy screenings and increase your costs. The fecal matter in the water must be delivered to the subsequent sewage purification processes. The wash compactor reduces the weight and volume of your screenings and in addition washes out more than 95% of fecal matter. Wash compactors provide high performance coupled with low operating costs.

Function
The unit can be directly charged via a screening unit, conveyor or conveyor belt. The screenings are conveyed within the wash compactor from the inlet zone to the washing zone. In the washing zone, service water is added and organic matter washed out. The wash water, which is rich in carbon, is released to the flume. The conveyor screw delivers the washed screenings to the pressing zone. The screenings are discharged via a discharge pipe to a container or conveyor.

Advantages and Specification

• washed out matter is returned to the flume
• easy retrofitting to an existing installation
• Volume, weight and disposal cost reduction up to 75 %

Screw Conveyor

Screw conveyors are used to convey sludge or solid matter like grit or screenings. The conveyor screw is constructed with or without a shaft.

Grit screw conveyors can be directly installed in a concrete tank or a stainless steel tank. The conveyed material is then carried to the discharge point like a pump sump or a classifier. For longer screws with shaft there are intermediate bearings to avoid contact between the screw and the trough. The result of this is that the abrasion is very low. For shaftless screws there is an inlay to protect the trough.

Advantages and Specification

• Single Screw Conveyors up to 20m distance
• can be movable
• suitable for municipal sewage plants and industrial waste water treatment

Package Inlet Work

The complete preliminary treatment of waste water in one compact plant includes:

fine screen - screenings treatment - grit trap - grease trap - grit classifier.

The wastewater passes the screen, solid materials are removed and water flows into the grit trap. This prevents sedimentation between screen and grit trap. A grease trap with fine bubble aeration generating an air roller is located upstream of the grit chamber.

Features:

• Optimum grit separation at loadings via lamella strip technology
• Low operating & maintenance costs
• High reliability through robust construction
• Can be supplied for throughputs of 5 - 160 l/s

MENA-Water Produktgroups

As we are dealing with all kind of water treatment we offer services and products around water technology. Our program is including all steps of the treatment process and all needed equipment.

• Pretreatment, screens & grit collection
• Secondary treatment aeration & mixing
• Advanced treatment dissolved air flotation, special treatment
• Sludge treatment storage, transport, dewatering
• Odour control reducement of smell and harmful gases
• Renewable Energy, Biogas, Wind, Solar
• Instrumentation & control analytics, plant control
• Pumps & flow regulation pumps, valves, penstocks