1. Jaroslav Pollert
Czech Technical University in Prague
Faculty of Civil Engineering
Department of Sanitary and Ecological Engineering

2. Outline
Ecological and economical
motivation
Development
 Design description and
operational principle
 Mathematical and
physical modelling
Installation
 First specimens
 Comparison with
conventional types
Conclusion and future

3. CSO - motivation
Collaboration with
HOBAS company
Using their production
Environmental pollution
from CSO
Decreasing of
suspended solids load
European Water
Framework directive
2000/60/EC
Easy installation and
operation

4. Development
Development in CTU
 Physical model
 Mathematical model
Main aim of the
development:
 Simple construction
 Cheap production
 Easy installation
 Decrease pollution load to
environment
 Easy operation
 Trouble free and safe
operation

5. TOK – Tube Combined Sewer Overflow
1200
Inflow part leads to
20
R1 0
accumulation chamber 600 600
100
R1 0
Scumboard protect overflow
against flotables which are
100
1200
R1
0
stored in accumulation chamer 600 600
R1 0
Shape of the overflow slit were
under development 200
1200
R1 0
200

6. Developing TOK
– mathematical and physical model
 Overflow slit
 Shape development for
decreasing suspended
solids overflow
 Contraction of the slit
on the end of CSO
decrease turbulences
 Comparison of
mathematical model
and physical model

7. Mathematical model
1200 1200
R10 R10
20
20
slit
Normal shape, scumboard, not too Normal shape, no scumboard, not too
linear pathlines linear pathlines
1200
R10
20 0
slit
20 0
R10
1200
Open shape on the end, scumboard, Open shape on the begining,
high turbulences on the end scumboard, linear pathlines

8. TOK Moravský Krumlov
 Easy installation
 2 pieces prepared in factory
 2 manholes
 Scumboard x cofferdam
 Temporary outflow

9. Scumboard x cofferdam
From scumboard you can easily create cofferdam
On the right side temporary outflow

10. Mathematical model TOK Děčín
•Simulation of separation
efficiencies in TOK Děčín
(path lines of particles d=150
μm, ρ=1800 kg/m3)

11. ResultsTOK Děčín
measuring x mathematical model
Mathematical model Separation efficiency
% d Density Sedimentation 2xQcrit 5xQcrit 7.5xQcrit
velocity
[m] [kg/m3] [m/hod]
Fraction1 50,0% 1,00E-06 1300 0,00049 30% 6% 2%
Fraction2 25,0% 1,00E-05 1800 0,131 46% 11% 4%
Fraction3 22,5% 1,00E-04 2600 23,77 78% 33% 18%
Fraction4 2,5% 1,00E-03 2600 593,19 100% 100% 100%
Overall efficiency 46,55% 15,68% 8,55%

12. Comparison with conventional types

13. Conclusion and future
Development of new CSO
Main aims were achieved
Mathematical model and physical model were
compared
Shape of the overflow slit were developed
Several TOKs were installed and more are planned
Moravský Krumlov, Děčín, Teplice …
Future – further development and improvement

14. 14

18. Overall results
cinf low − coverflow
η= ⋅100%
cinf low

19. Comparison with conventional
types

20. TOK Děčín •Inflow DN 1000
 High traffic street
 Overnight instalation