This document describes the HUBER Solar Active Sludge Dryer, which uses solar radiation to dry wastewater sludge in a greenhouse. It features a unique combination of sludge turning and transport through continuous drying process to evenly distribute the sludge. Drying the sludge reduces its mass and volume by up to 75%, lowering transportation costs and creating a product that can be used as fertilizer or secondary fuel. Case studies demonstrate municipal wastewater treatment plants around the world that have implemented this sludge drying technology successfully.

1. 1
HUBER Solar Active Sludge Dryer
A.T.E. HUBER Envirotech Private Limited
www.atehuber.com
V3.0 June 2018

2. 2
HUBER Solar Active Sludge Dryer
 Drying of wastewater sludge in
a glasshouse using incident
solar radiation
 Unique combination of sludge
turning and transport
 Continuous drying process
 Even distribution of the sludge
feed
An innovative, eco-friendly, and economic solution
for complete sludge management
Creates value from waste! Reduced sludge mass and volumes! Reduced logistical hassles
and transportation costs!

3. 3
HUBER Solar Active Sludge Dryer
Venting/escape
of saturated air flow
High-efficiency
drying zone
Basic drying zone
Fresh air supply
Wet sludge feed
Intensive ventilation
with large air flow,
high ventilator efficiency
Drying air transport
over the sludge bed
Discharge
Sludge drying with solar energy

4. 4
Benefits of sludge drying – creates value from waste
Sludge
screening
Sludge
thickening
Sludge
dewatering
Sludge
drying
Dried sludge -
fertilizer or
secondary fuel

5. 5
Benefits of sludge drying – reduced mass and volume
Dewatered sludge Dried sludge
Mass reduction
9tonnes/day ⇒ 3 tonnes/day
or
3285tonnes/year ⇒ 1095 tonnes/year
Volume reduction
9m3/day ⇒ 3.6 m3/day
or
3285m3/year ⇒ 1314 m3/year
Dry final sludge has 75% DS*, as compared to feed sludge with 25% DS
*Dried solids

6. 6
Benefits of sludge drying – reduced transportation costs
Transportation required for dewatered sludge
164
trucks*
65
trucks*
* 1 truck = 20 m³
Transportation required for dried sludge

7. 7
Benefits of sludge drying – less odour, dust
Reduced odour and dust due to:
 Intensive aeration of the whole sludge bed
 Backmixing (mixing of dried sludge with wet sludge) to enhance sludge
granulation process
 Sludge “rolled” by the shovel; produces compact, round granulates
 Shield device (optional) ensures open-pored granulate, destroys
agglomerated bulbs
 Sludge bed waveform creates larger exposed surface area
 Defined bed height ≤ 30 cm; prevents fermentation
Example of outlet sludge quality: granular
usually approx. 0.8 kg/l

8. 8
Additional benefits of sludge drying
Stable, easy to store
product
Increased heating value: 8-12
MJ/kg (5 times more than
dewatered sludge)
Dried sludge granules are clean
and easy to handle
Easy, economic operation:
Approx. 30 kWh electric ton of water evaporation
No wear parts for the first two years
Designed for highest evaporation rates,
thereby providing efficient drying
Turning device designed for a low
greenhouse (economic building) is
possible
Different feeding and
discharging possibilities

9. 9
HUBER Solar Active Sludge Dryer – sludge turner
Paddle/turning device
Control cabinet
Energy chain
Traction drive
Paddle drive
Shield drive

10. 10
HUBER Solar Active Sludge Dryer – sludge turner
The sludge is taken up by the rotating blade,
which rotates counter to the travel path.
The sludge is completely mixed, turned and
simultaneously transported forward.

11. 11
HUBER Solar Active Sludge Dryer – sludge turner
 Best mixing and aeration of the sludge
 High sludge aeration and mixing capacity of 15 m³/min (volume of sludge moved)
 Intensive sludge turning – each individual sludge grain is moved over a distance of 1.5 m during one
sludge turnover cycle
 99% of the sludge bed is moved

12. 12
HUBER Solar Active Sludge Dryer – PLC control
 Easy monitoring of all operating parameters
 Easy and simple adjustments of set points
for better process control
 Provides rapid feedback of critical
adjustments
 Online connection via internet for remote
monitoring / trouble shooting

13. 13

14. 14
References
15+ years of experience
72 projects (more than 50% projects with heat)
115+ machines in operation worldwide
200,000+ tonnes of sludge per year is treated by the HUBER SRT

15. 15
Case study - Mumbai, India
Location: Near Mumbai
Dryer type: SRT
Dryer area: 504 m²
Start-up date: August 2017
Sludge throughput: 1.400 t/a @ 20% DS
Final solids content: >85% TR
Energy supply: Solar
Greenhouse dimensions: 7m x 90m

16. 16
Case study - Bayreuth, Germany
Dryer type: 5 x SRT 11
Dryer area: 7.000 m²
Start-up date: December 2015
Sludge throughput: 10.000 t/a @ 26% DS
Final solids content: ~85 % DS
Energy supply: Solar + heat by damper register

17. 17
Case study - Cali, Colombia
Dryer type: 4 x SRT 9
Dryer area: 4.000 m²
Start-up date: March 2011
Sludge throughput: 15.000 t/a @ 25 % TS
Final solids content: Up to 90% TS
Energy supply: Solar + floor heating
Greenhouse dimensions: 4 x 10m x 100m

18. 18
Case study - Tooele, USA
Dryer type: 3 x SRT 11
Dryer area: 3.300 m²
Start-up date: March 2011
Sludge throughput: 5.500 t/a @ 18 % DS
Final solids content: Up to 90% TR
Energy supply: Solar
Greenhouse dimensions: 3 x 12m x 100m

19. 19
Case study - Gunstett
Dryer type: 2 x SRT 9
Dryer area: 900 m²
Start-up date: March 2008
Sludge throughput: 2.100 t/a @ 20 % DS
Final solids content: Up to 90% TR
Energy supply: Solar + heat pump
Greenhouse dimensions: 2 x 10m x 50m

20. 20
Case study - Penzing-Weil, Germany
Dryer type: 1 x SRT 9
Dryer area: 800 m²
Start-up date: October 2010
Sludge throughput: 1.000 t/a @ 20% DS
Final solids content: ~75% TR
Energy supply: Solar
Greenhouse dimensions: 10m x 90m

21. 21
Case study - Klodzko, Poland
Location: Near Wrozlaw
Dryer type: SRT/SE
Dryer area: 900 m²
Start-up date: August 2010
Sludge throughput: 1.200 t/a @ 25% DS
Final solids content: ~80% TR
Energy supply: Solar + floor heating
Greenhouse dimensions: 10m x 120m

22. 22
THANK YOU