DE4104451C2 - Rain overflow structure with a measuring device for determining the amount of overflow water - Google Patents

Description

The invention relates to a rain overflow structure, in particular rain overflow basin, with measuring Devices for determining the amount of overflow water according to the preamble of claim 1 or 2.

While so far in recent years running structures in mixed water sewerage (rain over spouts, pool overflows and clarification overflows) finally for the abandonment of mixed water ent load are increasingly based on of regulations and requirements the task of Proof of the water relieved when it rains create quantities. This requires the use of ent speaking measuring devices.

Basically there are different measuring devices for a quantity measurement at relief systems knows. For example, there is the height-dependent one Quantity measurement at an overflow threshold, the upper a sensor for determination on the water side of the water level or the overflow height. The Ent load quantity can be determined. It can measure value sensors are used, for example as a pressure transducer, echo sounder or bubbler are trained.

Furthermore, they are speed-dependent Known measuring devices, that is, to be determined amount of water in the defined pipe cross-section depends on the flow velocity. The Like measuring devices are, for example, inductive Flow meters (IDM) used in the relief line between an overflow structure, for example and a receiving drain is arranged. The Culverting is necessary so that the as a free mirror line trained discharge line always full is filled, because only then is a correct measurement can follow.

When determining the above amount of running water, however, the difficulty arises that about 70 to 80% of the annual at such a mixed building water relieved rela tiv small rain events, that is, rain rain nisse with little rainfall, basie Ren. The remaining amount of mixed water (20-30%) results from so-called heavy rain events, which lead to very high relief amounts. Out of it the problem arises that the measuring device must have very large measuring ranges in order to to be able to record a very wide discharge spectrum. For example, on a typical relief building during heavy rain (for example for 10 minutes) a water volume of up to 10,000 l / s chipped to the receiving water, so can do the same Structure in light rain and possibly over long periods the relief amount at 10 to 20 l / s. However, it must always be ensured that an accurate measurement of the overflow water quantity done. This is with the conventional measuring facilities not given.

The above-mentioned wide discharge spectrum requires measuring ranges from 1: 500 to 1: 1000, each yet - with the known measuring devices - with him significant measurement errors, especially in the lower Be rich, connected. For example, with a with height-dependent water level meter Measuring threshold an overflow amount of 10,000 l / s at a predetermined threshold length with 50 cm height overflows, with an overflow of 100 l / s or even 10 l / s only with a head in Centimeter or even in the millimeter range nen. This makes it clear that measurement errors without further up to 100% and more can occur.

Analogously moves with an inductive through flow meter that works depending on the speed, the flow rate at a discharge of, for example, 10,000 l / s at 12 m / s and at egg A minimum discharge of, for example, 100 l / s at 0.1 m / s or at 10 l / s only at 0.01 m / s. The one due to this wide discharge spectrum Measuring errors that occur are serious.

The measurement errors mentioned are particularly in the below ren measuring range not tolerable; they will still accepted today, obviously never someone has remedied this.

From the brochure of the "Gesellschaft für Meßtechnik", 5520 Bittburg, "Flow measurement at thresholds of Regenüberlaufen ", IFAT 90, Munich, is a rain overflow structure of the generic type known. For the measurement of rain reliefs, the Determination of the overflow height of an overflow threshold, the determination of the overflow height not only a point of the threshold takes place, then from it to determine the total relief amount, as this simplified assumption in practice to wrong results can lead. It is suggested to different places of the threshold the overflow height to determine because the water level is not level, but is designed as a curve. For determining the flow rate are along by several the threshold of parallel measuring devices Overflow heights determined and using a formula total amount of overflow water determined. With wide discharge spectra, so very different Amounts of water are correspondingly large Measuring errors.

The invention is therefore based on the object Rain overflow structure of the type mentioned at the beginning create with high accuracy the over flow of water despite the appearance of a very wide discharge spectrum can be determined.

This object is achieved according to the invention by the features of claims 1 or 2.

There are two in a row Measuring devices provided. The Evaluation device pulls to determine the overflow water the amount of the result of the measuring device, de ren measuring range is not exceeded and their Measurement result within the associated measuring range represents the largest possible relative value.  

A measuring device is included as an overflow threshold upstream, height-dependent measured value recording mer and the other measuring device than inductive flow meter.

Alternatively, the second one Measuring device as a pump, especially as a circle sel- or screw pump, trained to their operating time or their assigned through flow meter the measurement result is determined. The pump is preferred for an intermittent loading designed and with water level scarf ter connected. Will a certain water level exceeded, the pump takes action and this lowers the water level. Falls below Water level a minimum value, so the pump switched off. However, a maximum is about stepped out when pumping the pump out is enough to lower the water level, so the Measured value no longer from the pump, but from one another measuring device to form the overflow amount of water decreased for a larger excess flow of water is designed.

The drawings illustrate the invention hand of several embodiments and shows:

Fig. 1 shows a longitudinal section through a rain overflow structure according to any exporting approximately example,

Fig. 2 is a plan view of the rain overflow construction of Fig. 1 and

Fig. 3 shows a rain overflow structure according to a white direct embodiment of the invention.

Fig. 1 shows an exemplary embodiment of a rain overflow structure 1 , which has a series circuit comprising an overflow threshold 2 and an inductive flow meter IDM. In individual NEN a reservoir 21 is provided, which is limited by the overflow threshold 2 . Below the overflow threshold 2 there is a chamber 8 and a shaft 9 , the chamber 8 and shaft 9 being connected to a measuring tube 11 which has the inductive flow meter IDM. With a larger diameter tube 22 which is parallel to the measuring tube 11 , there is a further connection between the chamber 8 and the shaft 9th The shaft 9 is provided with a drain 10 .

In operation, the amount of overflow water is measured in small quantities using the inductive flow meter IDM (measuring device 5 ). If - for example during heavy rain - a high discharge quantity occurs, then not the measured value of the inductive flow meter IDM, but that of a measured value sensor MW (measuring device 6 ) is used, which determines the head h at the overflow threshold 2 . To prevent a small amount of overflow water from passing through the pipe 22 , i.e. not being available in the measuring pipe 11 , either a slide can be assigned to the pipe 22 or a further overflow threshold 2 can be provided in the chamber 8 (this is in of FIG. 2).

Fig. 3 shows a further embodiment of a rain overflow structure 1 with an overflow threshold 2 , to which a sensor MW (Meßvor direction 6 ) is assigned. Underwater, a sump 23 is provided in which a pump 24 is arranged, which is connected to water level switches 25 , 26 and 27 . At the lowest level is the water level switch 25 , at a medium level the water level switch 26 and at a highest level the water level switch 27 . The pump 24 is followed by an outlet 10 via a threshold 28 .

In operation speaks at relatively small overflow water levels of the water level switch 26 when reaching the appropriate level, which switches on the pump 24 . As a result, the water level drops such that the water level switch 25 speaks to, the pump 24 is switched off again. The amount of overflow water can be determined via the operating time of the pump 24 (measuring device 5 ). Alternatively, however, a flow meter can be assigned to the pump pressure pipe, which determines the amount of water overflow. Reaches - with a large inflow quantity - the water level in the area of the pump 24 so that the water level switch 27 responds, the pump 24 is switched off and the measuring sensor MW is used to determine the overflow water quantity. This is done in the usual way with the help of the Poleni formula.

It should also be made to a special feature representation in Figure 1, since there -. Graphic reasons - the tube is added 22 above the measuring tube 11 again. In reality, however, measuring tube 11 and measuring tube 12 or measuring tube 11 and tube 22 are at approximately the same height.

Claims (2)

1.Rain overflow structure, in particular rain overflow basin, with measuring devices for determining the amount of overflow water, of which at least one is a measuring sensor assigned to the overflow threshold for determining the overflow height, in particular for mixed water systems, characterized by the following features:

• - The measuring devices ( 5, 6 ) have different measuring ranges for larger and smaller amounts of overflow water and are in series with one another,
• - The first measuring device ( 6 ) for larger amounts of overflow water is the sensor (MW) of the overflow threshold ( 2 ),
• - The second measuring device ( 5 ) for smaller amounts of overflow water is an inductive flow meter (IDM) arranged on the underwater side in front of the first, with a parallel bypass tube ( 22 ), the premature start of which is prevented by a slide or a further overflow threshold in front of the bypass inlet,
• - An evaluation device always uses the measurement result of the second measuring device ( 5 ) when its measuring range is not exceeded, otherwise the measurement result of the first measuring device ( 6 ).

2.Rain overflow structure, in particular rain overflow basin, with measuring devices for determining the amount of overflow water, of which at least one is a measuring sensor assigned to the overflow threshold for determining the overflow height, in particular for mixed water systems, characterized by the following features:

• - The measuring devices ( 5, 6 ) have different measuring ranges for larger and smaller amounts of overflow water and are in series with one another,
• - The first measuring device ( 6 ) for larger amounts of overflow water is the sensor (MW) of the overflow threshold ( 2 ),
• - The second measuring device ( 5 ) for smaller amounts of overflow water is a detection device for the operating time of a pump ( 24 ) arranged underwater in front of the first measuring device ( 6 ) or an inductive flow meter (IDM) built into the pressure pipe of this pump, the motor switch of the pump ( 24 ) is connected to three water level switches ( 25, 26, 27 ) at a lowest ( 25 ), a middle ( 26 ) and a highest ( 27 ) level, the middle water level switch ( 26 ) the switch-on signal and the lowest water level switch ( 25 ) the There is a switch-off signal for the motor switch of the pump ( 24 ) and the highest water level switch ( 27 ) gives the switch-off signal for the motor switch of the pump ( 24 ) and the switch-on signal for the first measuring device ( 6 ),
• - An evaluation device always uses the measurement result of the second measuring device ( 5 ) when its measuring range is not exceeded.