Experimental investigation on the efficiency of a high side weir overflow

1999 ◽  
Vol 39 (2) ◽  
pp. 61-68 ◽  
Author(s):  
Gert Luyckx ◽  
Guido Vaes ◽  
Jean Berlamont

Most of the overflow structures in Flanders are ‘high side weir overflows’. For the design of these structures British guidelines are used. However, the design conditions for sewer systems in the U.K. differ from the Flemish design conditions. In Flanders, pressurised flow is in common use in the pipes of the sewer system. That is why tests have been carried out on a scale model of a high side weir overflow. The optimal dimensions are determined, using different model sediments. Also efficiency relationships have been determined. For a particular chamber geometry and particular flow conditions, the efficiency of a certain sediment fraction is only determined by the settling velocity of this fraction.

1999 ◽  
Vol 39 (9) ◽  
pp. 177-184 ◽  
Author(s):  
G. Luyckx ◽  
G. Vaes ◽  
J. Berlamont

Scale model tests were used to determine the efficiency relationships for a hydrodynamic separator (Storm KingTM) and a high-side weir overflow. With the help of these relationships optimal dimensions of an improved high-side weir overflow chamber could be found. The steady state efficiency for this improved overflow chamber seems to be comparable to that of a hydrodynamic separator, when both devices are subjected to the same surface load. On the other hand, during real storm events, the storage inside the overflow structure can play an important role. This role is investigated by calculating the removal efficiencies for both structures when 4 monitored storm events are used as input. When higher removal efficiencies are wanted, the storage effect gets more and more important and as a consequence the hydrodynamic separator can technically as well as economically compete with simpler structures like e.g. a high-side weir overflow. These findings are confirmed by a simple construction cost estimation.


1993 ◽  
Vol 27 (5-6) ◽  
pp. 153-164 ◽  
Author(s):  
S. Michelbach ◽  
C. Wöhrle

Sedimentation and transportation of mineral and organic pollutions in combined sewer systems are not completely understood. For better understanding, samples of sediment, slime and urban runoff were taken from the combined sewer system of Bad Mergentheim. The settling velocity of settleable solids was measured with a settling apparatus. Typical settling curves for sediment, slime and wastewater were put together. Some of the samples were analysed for heavy metals and organic micro-pollution. By this the relationship between settling velocity and the load of heavy metals can be shown. The gained data are of interest for the design of clarifier tanks for stormwater treatment.


2006 ◽  
Vol 54 (6-7) ◽  
pp. 101-108 ◽  
Author(s):  
A. Campisano ◽  
E. Creaco ◽  
C. Modica

Periodical cleansing operations prove necessary inside sewer systems in order to reduce hydraulic and environmental problems owing to the accumulation of deposits on the bottom of channels. For this objective, new effective hydraulic devices based on the scouring effects of flushing waves have been recently set up and adopted in many sewer systems. In this paper, the results of an experimental and numerical investigation on the hydraulic operation of the Hydrass flushing gate are reported. The experimental analysis has been carried out using a laboratory channel and a reduced scale model of the gate, in order to characterise the flushing waves generated by the device. The numerical analysis has been performed using a mathematical model specifically developed for the simulation of flushing waves inside sewer channels. The comparison of numerical results and experimental data has allowed evaluation of the applicability under unsteady flow conditions of the outflow relations determined for the Hydrass gate in a previous investigation under steady flow conditions.


2009 ◽  
Vol 60 (2) ◽  
pp. 475-482 ◽  
Author(s):  
Kees de Korte ◽  
Dick van Beest ◽  
Marcel van der Plaat ◽  
Erno de Graaf ◽  
Niels Schaart

In The Netherlands many large branched sewer systems exist. RTC can improve the performance of these systems. The objective of the universal algorithm of SmaRTControl is to improve the performance of the sewer system and the WWTP. The effect of RTC under rain weather flow conditions is simulated using a hydrological model with 19 drainage districts. The system related inefficiency coefficient (SIC) is introduced for assessment of the performance of sewer systems. The performance can be improved by RTC in combination with increased pumping capacities in the drainage districts, but without increasing the flow to the WWTP. Under dry weather flow conditions the flow to the WWTP can be equalized by storage of wastewater in the sewer system. It is concluded that SmaRTControl can improve the performance, that simulations are necessary and that SIC is an excellent parameter for assessment of the performance.


1992 ◽  
Vol 25 (8) ◽  
pp. 181-188 ◽  
Author(s):  
S. Michelbach ◽  
C. Wöhrle

Sediment and transportation of mineral and organic pollution in combined sewer systems are not completely understood. For better understanding, samples of sediment, slime and urban runoff were taken from the combined sewer system of Bad Mergentheim. The sedimentation velocity of settleable solids was measured with a settling apparatus. Typical settling curves for sediment, slime and wastewater were compiled. Some of the samples were analysed for heavy metals and organic micropollutants. By this the relationship between settling velocity and the load of heavy metals can be shown. The gained data are of interest to size clarifier tanks for stormwater treatment.


2010 ◽  
Vol 37 (3) ◽  
pp. 477-488
Author(s):  
Elizabeth Valentine ◽  
Kurt Kronebusch ◽  
David Z. Zhu ◽  
N. Rajaratnam ◽  
Sid Lodewyk ◽  
...  

Oblique weirs are commonly used in urban drainage systems to remove excess flow from a sewer, in particular, a combined sewer system that has limited conveyance capacity. It is important to understand the hydraulics of these weirs to properly monitor the amount of the overflows as well as to design and improve sewer systems. The Rat Creek structure in Edmonton, Alberta, is a combined sewer overflow structure with a weir at an oblique alignment to the centerline of the sewer. A physical model study of the structure was conducted. The results show that both the approach flow conditions and the chamber geometry can significantly affect the hydraulic performance of the weir and invalidate the application of standard weir equations. A unique flow regime with a linear head–discharge rating curve was observed. The effects of modifying the weir and the hanging baffle wall downstream of the weir were also studied and reported. The results of this case study help to improve the understanding of the hydraulics of oblique weirs in sewer systems.


1993 ◽  
Vol 27 (12) ◽  
pp. 187-190 ◽  
Author(s):  
S. Michelbach ◽  
C. Wöhrle

Sedimentation and transportation of mineral and organic pollutants in combined sewer systems are not completely understood. For better understanding, samples of sediment, slime and urban runoff were taken from the combined sewer system of Bad Mergentheim. The settling velocity of settleable solids was measured with a settling apparatus. Typical settling curves for sediment, slime and wastewater were put together. Some of the samples were analysed for heavy metals and organic micropollution to see the relationship between settling velocity and the load of heavy metals of settleable solids. The gained data are of interest for the design of clarifier tanks for stormwater treatment.


1998 ◽  
Vol 37 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Marie-Christine Gromaire-Mertz ◽  
Ghassan Chebbo ◽  
Mohamed Saad

An experimental urban catchment has been created in the centre of Paris, in order to obtain a description of the pollution of urban wet weather flows at different levels of the combined sewer system, and to estimate the contribution of runoff, waste water and sewer sediments to this pollution. Twenty-two rainfall events were studied from May to October 1996. Dry weather flow was monitored for one week. Roof, street and yard runoff, total flow at the catchment outlet and waste water were analysed for SS, VSS, COD and BOD5, on both total and dissolved fraction. Results show an evolution in the characteristics of wet weather flow from up to downstream: concentrations increase from the catchment entry to the outlet, as well as the proportion of particle-bound pollutants and the part of organic matter. A first evaluation of the different sources of pollution establishes that a major part of wet weather flow pollution originates from inside the combined sewer, probably through erosion of sewer sediments.


Sign in / Sign up

Export Citation Format

Share Document