Grit traps should be designed to remove over 95 % of sand particles with a diameter of 0.2 mm.
Removed grit slurries contain organic solids. Their organic content can be somewhat reduced with grit classifiers (See our COANDA Grit Classifier RoSF 3). However, only state-of-the-art grit washing can produce clean and reusable grit (See our COANDA Grit Washing Plant RoSF 4).
The following aspects should be considered:
- Circular Vortex grit cambers, like our VORMAX Grit Trap, are more compact and consume far less power than aerated grit channels.
- Power consumption of grit channel aeration is 0.3 – 1.0 kWh/(PT•a).
- Even with good aeration and after classification, removed grit slurries still contain 20 - 50 % volatile solids plus much water.
- Our Grit Washer RoSF 4 produces clean and reusable grit with < 3 % organics and < 10 % water with a power consumption of only around 0.1 kWh/(PT•a).
- Grit chamber aeration is not needed, or can be reduced, where grit slurry is thoroughly washed. This saves much power.
- Mass reduction by effective grit washing is 50 % or more. Fuel consumption and costs for transportation and disposal are thus minimized.