The importance of the ROTO-FLOW technology is in introducing the liquid at 90° relative to the lie of the wedge wire. This is used for the initial separation of solids from liquid & in all cases the effluent liquid is introduced tangentially on to the contra – rotating face. The screen will discharge over only one weir as discharge over more than one can cause excessive moisture at the bottom of the screen drum with the attendant problems of loss of efficiency & screen blinding.
This technology introduces liquid under minimum head loss conditions & rotates the screen in the opposite direction so that maximum shear velocity is achieved. This is used for the initial separation of solids from liquid & in all cases the effluent liquid is introduced tangentially on to the rotating face.
ROTO-FLOW screens are generally sized so that the initial separation of solids & liquids is achieved before the liquid reaches the bottom of the screen. This feature is the cause of a very substantial benefit if liquid is allowed to be conveyed along the bottom of a rotating drum, fibrous particles will lie longitudinally & can in many cases gain partial or full access through the screen wire. The importance of the ROTO-FLOW technology in introducing the liquid at 90° relative to the lie of the wedge wire therefore cannot be emphasized. The cut off point that decides the size of particle, which is either accepted or rejected by the screen, is also more defined & this reduces problem areas, which are encountered with other designs.
With reference to the diagram, liquid enters the in feed tank, which is designed to smooth out the flow. It then goes through an arc of 90° & is introduced tangentially on to the screen face where it is separated from the screen face agglomerate & are moved axially into the drainage area where further moisture is allowed to drain. The solids are then discharged over the end of the screen into a receiver or conveyor.
Para Cone
The Design combines the features of our standard screen & the cone. The first section where the dewatering or thickening takes place is parallel – sided, but the last section is flared to move the solids more quickly towards the discharge end.
The Paracone is designed for all these jobs which have a higher percentage of solids than normal. The cone screen is capable of handling three times the solids loading of our standard parallel-sided screen. Incorporated are all the unique Roto – Shear features, but it uses the natural helix of a cone to discharge the solids of thickened fibers from the screen.
Suspended solids larger than 95% of slot size are removed, plus greater than 50% of suspended solids down to half slot size.
All Microscreens are fabricated from strong heavy gauge 304 grade stainless steel construction with treated steel base frame and direct gear drive. The wedge wire drum being supported by, and rotating on, four long life trunnions.
A variety of optional equipment is available including 316 stainless steel construction, full SS or GRP shroud, drive lubrication, central greasing for the trunnions, discharge chutes and tanks.
Why Roto Flow ?
Firstly, the wedge wire lies length wise along the drum at right angles to the directions of rotation with the flat face of the wedge wire inside the drum. Secondly the liquid is introduced tangentially to the screen face so running down the screen in the opposite direction of the rotation of lthe screen drum.
Shower Sparges & Nozzles
Internal Shower Sparges – are included as standard. These have the benefit of maintaining the screen face in a clean condition whilst in operation. The positioning & angling of the nozzles is critical to the efficient removal of fibre build up & of any “stapled” fibres.
