Catalogue

Plants, equipment and machines for water treatment

GNAFO2

The central flow belt screen with metallic net filtering panels, GNAFO2 type, is suitable for water filtration of channels for water intake from sea, lakes, rivers and in general in presence of big flow rates. The GNAFO2 compared to a classic belt screen, has twice the surface filtration thanks to its installation with panels installed in parallel to the water flow direction. The inlet flow rate splits into two parts by a central opening duly sized and crosses the two opposite screen filtering sides to rejoin downstream the same.
In particular, the machine is mainly composed of: 
- a sturdy frame made of standard sections and press-bended sheets; 
- a belt provided with mobile elements, composed of a set of metallic net filtering panels installed on a couple of roller chain; the mobile elements are designed and assembled in a such way to generate in the meantime a large filtering surface and also a lifting system for collected screening material; 
- two cogwheels installed in the upper part of the screen for the direct handling of filtering elements, by roller chains; 
- two cogwheels installed in the lower part of the screen, to assure a precise direction of the chains; 
- a drive shaft installed on auto-ranging supports and between the upper cogwheels; 
- a sturdy gearbox, parallel gear shaft type and hollow shaft, double speed to field the different requirements of filtration; 
- a collecting tank of screening material lifted by the mobile elements, installed on the upper part of the screen and provided with an inside shaftless screw, for the removal of screenings outside the machine; 
- a gearbox, parallel gear shaft type and hollow shaft, for the rotation of the above screw; 
- a complete system for the cleaning of mobile elements, composed of two flights of pipes provided with nozzles and solenoid valve.
For the most part of its operation the machine doesn’t have moving parts; the rotation occurs when the level difference between screen upstream and downstream reaches a set value.
The simplicity of construction and the completely automatic cleaning allow this screen to always guarantee high performances and reliability .

Strengths

• GREAT VERSATILITY OF EMPLOYMENT IN CHANNELS HAVING DEPTH FROM FEW METERS TO A DOZEN METERS.
• HEAVY DUTY EQUIPMENT WITH EXPECTED LIFE EVEN LONGER THAN 30 YEARS.
• FILTRATION OPENING VARIABLE FROM 1 MM TO SOME CM.
• HIGH FILTRATION EFFICIENCY BEING THE FILTERING BELT CROSSED ONLY ONCE FROM THE WATER WITHOUT ANY DRAGGING OF SUSPENDED SOLIDS WITH FILTERED WATER.