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Wastewater Fine screen
In the year 2000 Spaans Babcock took over the assets of the German company Bormet, a manufacturer of fine screens with removable filter blocks for extremely easy maintenance and operation. This unique and patented system was brought to the market in 1990 and is still a revolutionary improvement on the conventional continuous belt screens. Spaans Babcock moved the production to its factory in the Netherlands, where the screen perfectly fits in with the range of heavy-duty equipment produced there. Worldwide more than 250 Bormet fine screens have been installed on municipal sewage treatment plants and industrial waste water plants. To learn more about the qualities and advantages of the Spaans fine screens please select from the menu on the left or simply contact us!
The operation of the Bormet screen is intermittent to minimise the wear and increase the SCR (Screening Capture Ratio). The screening material blind, the screen and the components smaller than the slot opening are also captured (cake filtration).
Intermittent operation will be triggered by measuring the water level (upstream and downstream) an using the difference for switching.
The concept of a continuous travelling filter band (like an escalator) enables the screen to collect all waste material including large or round solids, and to gently handle the screenings.
Hydraulic Properties
In order to guarantee correct operation of the screen, the optimum flow velocity between the elements is approx. 1.0 m/s. Higher flow velocities will press the screenings between the filter elements making the cleaning of the belt difficult. Lower velocities between the elements will enable the sand and grit to settle in the bottom of the channel. That is why Spaans Babcock always supply a flow control device (channel narrowing) to reach the optimum flow velocity.
The Bormet fine screen is a self-cleaning screen. In addition to the cleaning by gravity and high speed rotating brush, the Bormet screen has a double row of water sprays (the flow of the spray system can be reduced).
Three cleaning steps:
- Gravity + Outer spray pipe – tangential to the filter belt.
- Inner spray pipe – tangential to the brush, washing through the filter belt. Will remove the particles that are stuck between the elements.
- High speed rotating brush, fully equipped with 360 degrees of bristles. The centrifugal force created by the high-speed brush will prevent screenings from sticking to the bristles. Cleaning of the brush with the inner spray system.
The block design of the Bormet screen ensures low wear, simple maintenance and a Heavy-duty machine which minimises your total operational costs.
What is this unique block design?
The basic difference with other, conventional designs is to be found in the construction of the filter belt from stainless steel shafts and ABS elements:
Where all other available belts are built up like a giant network with a staggered arrangement of filter elements on several shafts, all connected to each other, the Bormet filter belt is based on an arrangement of individual horizontal blocks of filter elements grouped together on 2 shafts, forming a modular block.
Conventional design by others - Network construction
Due to the construction, the elements in the conventional filter belt are constantly pivoting and rubbing against each other, causing excessive wear.
Conventional design by others - Network construction
Due to the construction, the elements in the conventional filter belt are constantly pivoting and rubbing against each other, causing excessive wear.
Spaans Bormet - Block design
With the Bormet block design however, the elements within one block are fixed on two shafts and not rubbing against each other while there is not physical contact between the individual filter blocks.
The Spaans fine screen gives you
- a heavy-duty, corrosion- resistant machine
- quick removal of modular filter blocks with low downtime
- access into the filterbelt without pivoting the machine out of channel
- a machine non- sensitive to sand and grid
- low wear due to patented block design
- low operational and maintenance costs
- reduced odour and increased safety due to a fully covered machine
- a straight fit into existing channels
- easy modification of the slot width
- low power consumption
Design characteristics
- up to 4.2 metres wide without centre chain
- up to 15 metres deep
- installation angle 60°, 75° or 85°
- slot widths from 1 mm up to 25 mm