Gravity Drainage Deck (GDD)
Gravity Drainage Deck (GDD)
Dewatering for thinner sludge
Siebtechnik Tema GDD’s are used to dewater thinner sludge, with low suspended solids of 0.3-1.5 %. We manufacture the GDD’s in our factory in Revesby (greater Sydney, NSW) and have supplied over 60 units to various industries over the past 30 years. In many processes the GDD is coupled with a Belt Filter Press (BFP), thus feeding thickened sludge to the BFP for more effective dewatering.
Typical applications include:
- Sewage treatment applications including raw waste activated sludge; primary, aerobically & anaerobically digested sludge
- Other water treatment applications such as extended aeration ponds, dissolved air flotation sludge, alum lime water treatment
- Industrial applications such as pharmaceutical, food, dairy processing, paper mill, tannery and abattoir waste sludge
- Power and steel plant fly-ash and sinter waste sludge
- Mineral processing waste water
How it works
- A – Wastewater mixed with polymer is introduced.
- B – The mixture gradually rises where the polymer and sludge separate.
- C – Mixture is evenly and gently spread out across the belt width.
- D – The mixture “pools” and then is conveyed upward during which time free water drains through the belt. The thickening process is aided by the cutting effect of the belt support and furrowing effect of the ploughs.
- E- The thickened sludge is discharged away from the belt which is then doctored and washed before returning to accept more sludge.
Models
Table with different models
Optional extras
As standard the GDD is supplied complete with a flocculation tank including 0.37 kW mixer, safety lanyard switches, low air and water pressure switches, belt drift switches, guards and mechanically variated main drives or suitable for VSD control (by others).
We generally offer the following optional extras:
- Other dry sludge handling equipment such as as conveyor belts, sludge bins etc.
- On site installation by our service technicians
- On site commissioning assistance by one of our engineers
Materials of construction
Equipment frames are made from epoxy coated mild steel, while all wetted parts including filtrate trays, flocculator tank, spray bars and fasteners are 316 stainless steel, rubber covered rolls.
Alternatively, the frames can also be manufactured from stainless steel.
Advantages
- Low capital cost
- High capacity for small space requirement
- Low polymer requirement
- Minimal maintenance
- High capture efficiency
- Low power usage
