Jaroslav PollertCzech Technical University in Prague

Faculty of Civil EngineeringDepartment of Sanitary and Ecological Engineering

OutlineEcological and

economical motivationDevelopment

Design description and operational principle

Mathematical and physical modelling

InstallationFirst specimensComparison with

conventional typesConclusion and future

CSO - motivationCollaboration with

HOBAS companyUsing their

productionEnvironmental

pollution from CSODecreasing of

suspended solids load

European Water Framework directive 2000/60/EC

Easy installation and operation

DevelopmentDevelopment in CTU

Physical modelMathematical model

Main aim of the development:Simple constructionCheap productionEasy installationDecrease pollution load

to environmentEasy operationTrouble free and safe

operation

TOK – Tube Combined Sewer Overflow

Inflow part leads to accumulation chamber

Scumboard protect overflow against flotables which are stored in accumulation chamer

Shape of the overflow slit were under development

1200

R10

600 600

20

100

100

200

200

1200

600 600

1200

R10

R10

R10

R10

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

Mathematical model

200

1200

R10

1200

20

1200

20

200

1200

R10

slit

slit

Normal shape, scumboard, not too linear pathlines

Normal shape, no scumboard, not too linear pathlines

Open shape on the end, scumboard, high turbulences on the end

Open shape on the begining, scumboard, linear pathlines

TOK Moravský KrumlovEasy installation

2 pieces prepared in factory

2 manholesScumboard x cofferdamTemporary outflow

Scumboard x cofferdam

From scumboard you can easily create cofferdamOn the right side temporary outflow

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

ResultsTOK Děčínmeasuring x mathematical model

Mathematical model Separation efficiency% d Density Sedimentation

velocity2xQcrit 5xQcrit 7.5xQcrit

[m] [kg/m3] [m/hod]Fraction1

50,0% 1,00E-06 1300 0,0004930% 6% 2%

Fraction2

25,0% 1,00E-05 1800 0,13146% 11% 4%

Fraction3

22,5% 1,00E-04 2600 23,7778% 33% 18%

Fraction4

2,5% 1,00E-03 2600 593,19100% 100% 100%

Overall efficiency 46,55% 15,68% 8,55%

Comparison with conventional types

Conclusion and futureDevelopment of new CSO

Main aims were achievedMathematical model and physical model were

comparedShape of the overflow slit were developed

Several TOKs were installed and more are plannedMoravský Krumlov, Děčín, Teplice …

Future – further development and improvement

14

Overall results %100inf

inf

low

overflowlow

c

cc

Comparison with conventional types

TOK Děčín

High traffic streetOvernight instalation

•Inflow DN 1000