NL1041492B1

NL1041492B1 - A sewage water level measuring system.

Info

Publication number: NL1041492B1
Application number: NL1041492A
Authority: NL
Inventors: Halbe Gerrit De Vries Ir; Eldert Maria Van Baar Jacobus
Original assignee: Joannes Adrianus Michael Clemens Van Helvoort
Priority date: 2015-09-25
Filing date: 2015-09-25
Publication date: 2017-04-19

Abstract

The invention concerns sewage water level measuring system (fig.ex.-1) with Cadanic suspension within a standardised mounting frame that can be fitted easily and very quickly in most common manholes (fig.ex.-2). The device measures, detects, collects and transmits data. These data are used for optimalisation of sewerage design and for monitoring the current/flow in cases of excessive load to enable appropriate (re) action. The system is built up from several independently operating components, which together generate reliable and reproducible data.

Description

A sewage water level measuring system

The invention concerns an installation (a device) for measuring sewage water levels that can be mounted quickly and easily in a standard manhole of any conventional gravity sewer system. The system serves two purposes. On the one hand it can be used to register overflow to surface water, on the other hand it can monitor throughputs (performance) based upon which relevant maintenance actions can be planned. The measuring system consists of several independently functioning components. Together these components detect, measure, collect and relay data.

This combination of independent components yields accurate and reproducible measurements and reliable data transfers as a result of: 1. The simple and very efficient way the device is mounted in the manhole 2. The principle of ultrasonically measurement 3. The hybrid communication system from within the manhole to the <SAAS> application 4. The auto-positioning (cardanic principle) and auto calibration facility which is an important characteristic of the design

Timely processing of accurate data (and appropriate follow up) allows for better management of the sewerage system.

The Problem / the Challenge

Societies/communities require well functioning sewerage systems. These systems are designed and built with the aid of intelligent software applications to perform optimally. However, in practice, excessive loads often expose wrong dimensioning of the sewerage system leading to flooding or overflow of raw sewage into surface water causing serious public health concerns. On the other hand, systems can be grossly over dimensioned without this ever being detected. So far accurate monitoring of the dynamics in the sewerage system has been virtually impossible. Measurements are often less accurate and data transmission is not always possible.

This invention overcomes the above mentioned problems, it produces accurate data for a long period of time without requiring any (re) calibration so that local authorities can have reliable figures about throughput and overflow; the data provides feedback for the design software application for validation and optimalisation. Designs can be improved continuously and cost of building and maintenance can be reduced.

Current systems for measuring flow

The flow in sewerage systems is commonly quantified by measuring the height of the water level in front of an obstruction, which is placed in a manhole or in so called measuring gutter. The following systems are used for measuring the level of the backwater in front of the obstruction (level detection): - A bubbling system in which the pressure is measured that is required to maintain a constant air flow in a halfopen pipe probe that is submerged at a fixed point in the backwater. - An echo or ultrasonic system in which the travelling time is measured of pulses of high frequency sound emitted from a fixed position in a manhole which are echoed back by the water surface

Less common measuring systems include: - Pressure box system: a pressure box mounted at the bottom of the manhole measures the hydrostatic pressure of the water body above it - Float level systems in which the position of a simple mechanical float is a measurement for the water level - Electrode probe (needle) system, an electro-mechanical system in which a probe is lowered at fixed time intervals from a fixed position until it reaches the water surface.

None of the above mentioned systems have a standard / universal mounting system

Disadvantages / shortcomings / drawbacks of current systems for measuring flow in sewerage.

Today's flow measuring systems are mounted in manholes as compact systems in which sensors, data loggers and data transmitters are integrated. Handy (practical and efficient) as this might seem, this method has the following drawbacks: - Sensor o Contamination, dirt particles clinging to the sensors reduce accuracy; periodical maintenance is required (2 x year) o Energy inefficiency: long settling time and 4-20mA signal output draw heavily on battery capacity o Drift: the mechanical parts of pressure sensors' require periodical calibration

Data transfer o Poor GSM connectivity as manhole works as a Faraday cage o Moisture damage, electronic parts are vulnerable in high humidity conditions o Limited autonomy as GSM signal consumes much energy, especially when field strength weakens. - Installation issues o The GSM antenna needs to be installed outside the man hole o For accuracy sake sensors must be installed and calibrated at a fixed point in or above the water flow o No universal mounting system; installation and/or maintenance require that roads be closed for several hours

Solutions resulting from the invention

The sewage level measuring equipment (flgl) is placed on top of the outer ring of the manhole. The manhole is closed with the original manhole cover.

The sewage water level measuring device consists of a mounting frame (fig2) from which a diving bell (figl-1) is hung. This bell is open at the bottom but given the nature of a diving bell, no water can enter; it provides room and shelter for the electronic measuring equipment (figl-2). 1. Mounting frame. (Fig 2): This mounting frame fits like a shim in the upper ring of the manhole and has three parallel bars. The diver bell is attached to the ribbed middle bar (fig2-l). The ribs restrict the clock’s sideways movements in the parallel direction. The two outside bars (fig2-2) restrict the swinging in the cross direction. This way of mounting the diver bell (figl-1) ensures that rising water creates an air bubble that is large enough to guarantee that the sensor and the sensitive electronic equipment which are positioned high above in the bell, can never be reached by water during extreme conditions and thus cannot be damaged or contaminated by moisture. 2. The diver bell (fig 1-1) is attached to the ribbed bar (fig2-l) as a cardanic suspension ensuring that the diver bell (figl-1) will always be in a perfect perpendicular position when making measurements. 3. The inner casing (fig 1-2) that contains all electronic equipment is mounted inside the bell using a bayonet mount (figl-3). 4. The battery pack is optional, it extends the autonomy of the system 5. The data logger contains the power supply for the signal handling with the sensor and sends the data using RF to the nearby solar powered relay unit 6. The ultra sound sensor performs the contactless measurement (of the distance between the sensor and the water surface)

Advantage compared to existing solutions:

Data logger o RF instead of GSM provides energy efficient and reliable connection o Damage by moisture is virtually impossible o Smart Sample software adjusts measuring frequency to δ (1-20 measurements per minute) - Sensor o No contamination of measuring parts because of contactless measuring o Energy efficient settling time and signal output o Auto-calibration by continued measuring of object in resting state (in standby) (measuring of distance to bottom of sewer in dry conditions o Easy exchange, different physical values can be measured - Installation o A standardised positioning in relation to the top of the manhole (road surface) providing accurate location in relation to NAP (sea level). o Very short installation time, no need for road closing. o Standard size mounting fits 80% of manholes in use. o Auto-gyro (cardanic) mechanism

Claims

!. Rioolwater niveau meetinrichting (figl) voor een zogenaamd vrijverval rioleringsstelsel inzetbaar vanuit twee gebruikbehoeften,enerzijds voor het registreren van overstort aan het oppervlaktewater en anderzijds voor het in kaart brengen van de prestaties t.b.v. onderhoud, met het,kenmerk, dat de duikersklok met de meetsensor volledig cardanisch is opgehangen.! Sewage level measuring device (figl) for a so-called free-fall sewage system that can be used for two needs, on the one hand for registering overflows to surface water and on the other hand for mapping performance for maintenance, characterized in that the diver's clock with the measuring sensor is fully is hung cardanically.

2. Rioolwater niveau meetinrichting (figl) volgens conclusie 1, met als kenmerk, dat de stang (fig2-l) waaraan de duikersklok is opgehangen is voorzien van ribbels zodat de duikersklok niet verschuift over de ophangstang bij onverhoopt hoog water.Sewage level measuring device (Fig. 1) according to claim 1, characterized in that the rod (Fig. 2-1) on which the diver's bell is suspended is provided with ridges so that the diver's bell does not slide over the suspension rod in the event of unexpected high water.

3. Rioolwater niveau meetinrichting (figl) volgens conclusie 1 en 2, met als kenmerk, dat de stang (fig2-l) waaraan de duikersklok is opgehangen is voorzien van ribbels zodat de zwenkhoek van de duikersklok wordt beperkt.Sewage level measuring device (Fig. 1) according to Claims 1 and 2, characterized in that the rod (Fig. 2-1) on which the diver's bell is suspended is provided with ridges so that the swivel angle of the diver's bell is limited.

4. Rioolwater niveau meetinrichting (figl) volgens conclusie 1, metals kenmerk, dat de twee parallelle stangen (fïg2-2) de zwenkhoek van de duikersklok .beperken in de richting loodrecht op de middelste stang.The sewage level measuring device (Fig. 1) according to claim 1, characterized in that the two parallel rods (Figs. 2 - 2) limit the pivot angle of the diver's bell in the direction perpendicular to the middle rod.

5. Rioolwater niveau meetinrichting (figl)volgens conclusie 1, met als kenmerk, dat de gefixeerde ophanging van de meetinstallatie op de putrand (fïg2) een gestandaardiseerde afhangdiepte ten opzichte van N.A.P garandeert.Sewage level measuring device (Fig. 1) according to claim 1, characterized in that the fixed suspension of the measuring installation on the well edge (Fig. 2) guarantees a standardized suspension depth with respect to N.A.P.

6. Rioolwater niveau meetinrichting (figl)volgens conclusie 1, met als kenmerk, dat er middels contactloze meting door de plaatsing van de sensor (figl-4) er geen vervuiling van de sensor optreedt.The sewage level measuring device (Fig. 1) according to claim 1, characterized in that there is no contamination of the sensor by means of contactless measurement due to the placement of the sensor (Figs. 4).

7. Rioolwater niveau meetinrichting (figl) volgens conclusie 1, met als kenmerk, dat door contactloze meting en plaatsing van de datalogger in de duikersklok er geen vochtschade zal optreden aan de datalogger.The sewage level measuring device (Fig. 1) according to claim 1, characterized in that no moisture damage will occur to the data logger due to contactless measurement and placement of the data logger in the diver's clock.