EP1279774A1 - Method for managing cascade waves in sewer networks - Google Patents

Abstract

Any sewage channels (15) extending in flow direction can be of flat construction below e.g. weirs, gates, etc. (30), without any need to increase the diameter of continuing pipes while maintaining drainage performance. To compensate for reduced channel bottom inclination, the variable hydrostatic pressure levels (3) of the dammed cascade volumes (17), activated above the run-off summit, are utilized by the weirs etc. with corresponding pressure line drop (5).

Description

The present invention relates to a method for KS K askaden- S chwall management of sewer networks, in which the sewer lines running in the direction of flow can be laid flat below the quickly movable control systems to be arranged in the form of weirs, slides, etc., without the further pipe diameter D For the same drainage capacity, larger dimensions have to be used, since to compensate for the bottom slope J _s to be reduced, the control of the usable hydrostatic pressure heights H _SD to be activated above the drain apex of the accumulated cascade volumes via the control systems with a corresponding pressure line slope J _{D is} used. Further optimization of the sewer network management through the use of hydraulically movable up to 10 m / min fast weirs {6} and slide systems {7} is to be significantly improved by the presented procedure for the possible reduction of the investment and follow-up costs. The current state of the art is given in the following bibliography.

Bibliography:

• {1} Dohmann M., Weyand M.
  Analysis and classification of local control devices in sewer systems RWTH Aachen 1990 issue 117
• {2} Weikopf M.
  The mixing system with its previous shortcomings and trend reversal towards the MSR cascade and relief technology
  Correspondence sewage 7/95
• {3} Weikopf M.
  The KSE K askaden-, S and E chwall- ntlastungstechnik as a possibility for optimization of future-oriented mixing systems
  Lecture on the 5th Chinese - German Environment Symposium
  Guangzhou June 1997
• {4} Weikopf M.
  Sewer network management with cascade, surge and relief technology Fundamentals of KSE technology and process control
  VDI / DMA conference on November 22/23, 1999 in Langen
• {5} Uecker KJ
  Tables for the calculation of stoneware pipes according to Prandtl-Colebrook Fachverband Steinzeugindustrie eV
• {6} Weikopf M.
  DE 36 16 418
  Controllable weir for flushing sewer systems and processes for delayed drainage
• {7} Weikopf M.
  EP 0 918 113
  Slider system for continuous control

According to the previously common methods for dimensioning sewer pipes {5}, it is assumed that the cross-sections of the sewer system should be designed so that a predetermined amount of water can theoretically flow out when the pipe is at the apex. The available cross-section of the tube is fully utilized without the Line overpressure arises. In addition, deposits, and thus unpleasant odors, can occur, especially at night when there are lower outflows in mixed and dirty water systems, as well as in larger channels with correspondingly reduced partial fillings. Subsequent rinsing pulses with correspondingly higher inflow quantities from rainwater, especially with mixing systems, can impair the operation of the sewage treatment plant.

The most important investment costs in the construction of sewage networks are not caused by the delivery and laying of the pipe systems, but rather the decisive factors are the costs of excavation, shoring, water drainage and special structures such as pumping stations, curve structures, shafts etc. derived from the necessary depth, as well as the associated technical equipment , The main problem areas of wastewater sewerage are still the topic of sedimentation and odor nuisance with the resulting hydrogen sulfide corrosion, because, for example, continuous, automated ventilation of sewerage systems has not been part of the rule of technology so far, since the related investment and follow-up costs appear to be unsustainable. The operating costs incurred to maintain the sewerage networks and the problem of pipe renovations during operation are moving more and more into the foreground.For these reasons alone, it is inevitable to use the possibilities of sewer network management so that the steady increase in costs for wastewater fees will be much flatter in the future.

The present invention has therefore set itself the task of reducing the KS K askaden- S chwall management for existing and planned sewerage systems for the reduction of investment and subsequent costs thereby greatly in which compared to the previous design practice, the necessary inclination for controlled and time clocked derivative of Q _max not be implemented via a necessary bottom slope J _S , but this is more optimally achieved by an at least adequate pressure line slope J _D via control systems such as weir and slide systems etc. in the discharge area of cascade volumes to be defrosted with the associated water level layers WSP to be activated.

The maximum design pressure H _SD to be activated is the respective design limit of the control systems, the weir the stroke or the slide the maximum height of the insert position.

This procedure has the further advantage that the cross sections do not have to be enlarged because the hydrostatic pressure head H _SD above the discharge apex can be activated by closing control systems in the upstream cascades. Due to the possible flatter laying of the further sewer routes, intermediate pumping stations with correspondingly reduced hydrostatic head h _red can be dimensioned according to formula [1b]. Even small amounts of feed water that flow via frequency-controlled pumps, for example at night to the subsequent cascade, can be used to activate the necessary water level positions WSP by temporarily closing the control system in order to achieve optimal flushing effects in the drainage lines with a corresponding ventilation effect

When generating different surge heights in the range 0 <SHD> D , a wide variety of optimizations such as volume shifts can be controlled with qualitative mixing processes, eg oxygenation with short surge waves and anaerobic transport with longer waves. The serial and parallel activation of cascades in the sewage network open up new possibilities for qualitative and quantitative management with significant savings in investment and

Follow-up costs.

The mathematical relationships for realizing the reduction of the bottom slope J _S and their effect for the adequate activation of the necessary pressure line slope JD is illustrated by the following formula approaches: $${\text{SE = 0 = -js × L + h}}_{\text{red}}{\text{+ J}}_{\text{red}}{\text{× L + D + H}}_{\text{SD}}\text{hub}$$

By transforming the equation [1] one obtains the static pressure head that can be activated above the pipe crown : $${\text{H}}_{\text{SD}}{\text{= Stroke (D + h}}_{\text{red}}\text{) +}\frac{{\text{J}}_{\text{s}}{\text{- J}}_{\text{red}}}{\text{L}}$$

By transforming equation [1a] we get the usable slope difference: $${\text{H}}_{\text{red}}{\text{= Stroke (D + H}}_{\text{SD}}\text{) +}\frac{{\text{J}}_{\text{s}}{\text{- J}}_{\text{red}}}{\text{L}}$$

If several cascades are activated, the following applies based on formula [1b]

The basic equation for determining the reduced base difference [h1] from the cascade outlet and the sole inlet pumping station is as follows: $${\text{SE = 0 = h}}_{\text{1}}{\text{+ D + J}}_{\text{D}}\text{× L hub}$$

Transforming equation [2] gives h ₁ $${\text{H}}_{\text{1}}{\text{= J}}_{\text{D}}\text{× L + D hub}$$

Fig. 1 shows a sketch of the structural relationships in one

Gravity feed [8] in accordance with the direction of flow [6] to the cascade [16] in conjunction with the associated process variables to KS K askaden- S chwall management of a secondary channel line [15]. In the sense of the method, the cascade [16] is started up by a control system [30] in this case a weir [33]

Print line [4] pent up. By quickly lowering the weir [33] , a programmed surge wave [25] with an associated pressure line [4] and the surge height [24] to be activated can be generated, which causes a corresponding surge wave flattening [26] according to the route length [31] . It can also be seen that a possible activation of the pressure height [3] via the discharge apex [1] below the control system [30 ] enables a reduction in the slope of the sole [29] , which does not increase in size in the form of a gradient difference [9] with the same discharge capacity of the pipe diameter [20] must lead. The pumping station [18] to be arranged at the low point at the end of the flatter canal route [15 ] is therefore in the Location with a reduced delivery head FH [7] to pump up the incoming free-level feed [8] into another cascade [16] .

FIG. 2 shows a sketch with two sewer lines [15] connected in series, in each of which a further control system [30] is arranged. Compared to FIG. 1, additional cascade volumes KV [17] in the upstream sewer pipe [14] of the control system [30] are activated. The intermediate pump station [18] corresponds functionally to the conditions of the last sentence from Fig. 1. The additional arrangement of, for example, another control system [30] in the sewer route [15] makes it clear that further pressure heights H _SD [3] can be used for management and optimization in the sense of the method for sewer networks [13] . The delivery heights FH [7] to be reduced for the pumping stations [18] and the variable pressure line gradient J _D [5] within the route lengths [31] that can be activated in a variety of ways are illustrated.

Fig. 3 shows a diagram with the evaluation of a water level-runoff relationship on the basis of the previous dimensioning instructions {5} according to the recognized rules of technology in comparison with the method according to the invention. Here, the method advantage is evident, for example, if the original Qmax If the gradient had been J _s = 2 ‰ and the above-mentioned gradient was now halved to J _s = 1 ‰, the same drainage capacity is maintained while maintaining the original pipe diameter D [20] of DN 1000 with an increase in the pressure head H _SD [3] to 1 , 00 m corresponding to a minimum stroke _min of 2.00 m by a control system [30] .

However, since weirs can currently be produced with a stroke of up to 4.00 m [12] , the remaining pressure head difference DHD = stroke [12] - stroke _min = 2.00 m can be activated for further variant relationships according to the method according to the invention and, in extreme cases, for example can be used in the bottom slope [29] up to the negative bottom slope area.

List of reference numbers

1. Process apex 2. Difference height cascade - inlet sole pump station: h ₁ 3. Static pressure height above apex: H _SD 4. Print line 5. Pressure line gradient: J _D 6. Flow direction 7. Head: FH 8. Free-level inlets 9. Slope difference reduced: h _red 10. Height of WSP location: 11. Height difference for J _D : H _DJ 12. Stroke applies to weirs: stroke 13. Sewerage network 14. Sewer pipes 15. Canal route 16th cascade 17. Cascade volume: KV 18. Pump station Cross section 20. Pipe diameter: D 21. Pipe gradient reduced: J _red 22. Top filling 23. Slider 24. surge heights: SH 25th surge wave 26. surge wave flattening: SWA 27. Bottom difference of the cascade: h ₀ 28. Sole inlet 29. Sole slope : J _s 30. Control system 31. Route length: L 32. Water level: WSP 33rd weir

Claims (6)

A process for the KS K askaden- S chwall management of sewage networks [13], in which extending in flow direction [6] channel paths [15] below to be disposed of, quickly movable control devices [30] in the form of weirs, sliders can be laid flat, etc. without the further pipe diameters D [20] having to be dimensioned larger for the same drainage capacity, since in order to compensate for the bottom slope J _s [29] to be reduced, the control of the usable variable hydrostatic pressure heights H _SD [3 ] to be activated above the drain apex [1] ] of the accumulated cascade volume KV [17] can be used via the control systems [30] with a corresponding pressure line gradient J _D [5] . Process for KS management according to claim 1, characterized in that in order to achieve a Q _max surge in the channel route laid flat [15], the associated hydrostatic use of the cascade volume KV [17] is carried out by timed closing of the upstream control system [30] , thus also different Inlet quantities from free-level inlets [8] or delivery capacities of the pumps within the pumping stations [18] can contribute to the necessary activation of the hydrostatic pressure line [4] in the cascade [16] . Process for KS management according to claim 1 to 2, characterized in that the flatter duct route [15], depending on the necessity, by programmed opening of the control system [30] for activating different surge heights SH [24] in partial to full filling contributes to the optimization of the duct network ventilation and it is also possible to achieve a permanently automated sewer cleaning. Process for KS management according to claims 1 to 3, characterized in that, depending on requirements, further control systems [30] can be arranged in the further sewer line [15] so that the cascade volume KV [17] in the upstream sewer network [13] is repeated depending on the usable pressure heights H _SD [3] can be used for further control-related optimizations, eg of surge activation, air changes, etc. Process for KS management according to Claims 1 to 4, characterized in that further pumping stations [18] connected in series at the end of the flattened sewer lines [15] with correspondingly lower hydrostatic delivery heads FH [7] according to the associated pressure head H _SD [3] from formula [ 1b] can be planned and expanded. Process for KS management according to claims 1 to 5, characterized in that by generating alternating surge heights [24] in the range 0 <SHD> D the most varied optimizations such as volume shifts with qualitative or quantitative mixing processes, for example oxygen input in the case of short surge waves and anaerobic transport longer waves, as well as, in particular, parallel staggered activation of cascade volumes KV [17] for mixing up and averaging different loads of dirt directly below the merging of sewer lines [15] .

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