Ensuring residential development with engineering communications is an important aspect of improving the comfort of living. Accommodation in an individual house has a great water consumption for economic needs without subsequent disposal: watering the garden, garden, water consumption by people and animals, etc. In order not to pay for water management services for consumed water, the installation of accounting devices is required. wastewater. The counter will show that it is realistic in the sewer, much less water goes, which enters the house.
Wastewater flow meter is a high-tech device having electronic components in its design and ensures the accuracy and reliability of measurements. The execution of the instrument base and the assembly nodes allows you to work in chemically aggressive environments, without loss of reliability and accuracy of measurements.
Sewer meters are divided into the following types, depending on which principle of operation underlies their work:
According to the measurement method, the drainage instruments are divided into two types:
High-precision devices designed to measure the amount of liquid sewage. Measurements occur using sensors using the "Speed \u200b\u200bSpeed" method that are easily installed in the collector. Used in open channels, samotane systems, non-free pipelines, in the industrial sphere for commercial accounting. When applying the instruments with hydrostatic sensors, in addition to controlling discharge volumes, monitoring the sewage network is monitored.
Installation is carried out inside the pipeline or channels without additional construction work.
The work of ultrasonic sensors is based on measuring the difference in the time of passage of ultrasonic oscillation pulses in the direction of flow of fluid flow and against it. Sensors (piezoelectric converters) are installed on the measuring site), which initiate the excitation of these pulses.
The ultrasonic sensor is installed at an angle relative to the flow cross section. Speed \u200b\u200bcan be measured by one or two rays of ultrasound oscillations. Sensors work alternately, first as the emitter, then as a receiver. The movement of the fluid causes a change in the time of the full propagation of the flow signals and against it. Based on the obtained signals, the speed and volume of wastewater is determined in the pipeline.
The advantages of the instruments of this type lies in their versatility, the possibilities of installation in pipelines of any geometry with a diameter of up to 9 m. Measurements occur in any direction of flow. The construction of additional wells or measuring cameras for installation of the device is not required.
The disadvantages of devices include the need for constant sensor cleaning. Inhomogeneity of the effluent, the presence of bubbles, suspension reduce the reliability of the indicators. Measurement error reaches 5%.
These are simple, but reliable devices for measuring the volume of wastewater, including crude. Apply on samotane and pressure sewer systems, provided that the pressure in the pressure drain does not exceed 40 bar.
The principle of operation of the flow meters is based on measuring the electromotive force (EMF), which occurs in wastewater when passing through an artificial magnetic field. The flow rate of the fluid is directly proportional to the emerging EMF, which is converted to the signal coming to the controller's display. Measurement of volume volumes is possible only if they carry out an electric current, as the effects of the instruments are based on the Faraday law (magnetic induction). The liquid that passes through the magnetic field acts as a moving core. It initiates the electric current, depending on the speed of the effluent.
The advantage of electromagnetic devices is their versatility, they allow you to measure any kinds of liquid waste conductive electrical currents, including crude drains. The devices stably show high-precision data provided the electrode self-cleaning system.
Note! The disadvantages include unstable work in the presence of strong electromagnetic interference. The cost of flow meters depends on the diameter of the pipe or channel, since the execution of the primary converter should always be full.
Scope of instruments - non-pressure open and closed sewer channels. The principle of operation consists in measuring the level and middle flow rate. Measurements are carried out constantly. Channel dimensions, information about the current value of the flow level can calculate the current value of the transverse section of the section cross section. The volume of waste is defined as a product of the flow of passing uncleanness per unit of measurement time. The performance of the device is defined as a product of the flow cross section at its speed.
The device is a device with a lever fixed on the axis, which is rigidly attached a spherical float. At the other end of the lever, the lever deviation angle sensor is set relative to the vertical to the horizontal line. In the absence of drains, the lever is in a vertical position. In the presence of drains, the float rises or lowers, changing the angle of inclination depending on the level of flow level in the pipe. Through the testimony of the angle of inclination determines the level of unclean.
To measure speed, another node is used, which is a rotary blade made of stainless steel. The blade is fixed on the axis. One end of the blade is freely descended into liquid waste. A sensor is enshrined on the axis, which shows the flow rate at the corner of the blade deviation depending on the strength of the flow.
These instruments provide high accuracy of the measured settings for accounting, regardless of the presence of contamination in the pipe and other factors.
Before choosing a model of the flow meter, you need to know which requirements are presented to the sewage system and which type of water pipes is used.
Sewer networks can be divided into open and closed. Closed networks are divided into pressure and non-free. Open channels include open channels. On the pressure channels, the drains move under the influence of pumps, in non-perm, as well as open - gravity due to the tilt of the pipeline.
To measure in pressure pipelines, devices with sensors use. Electromagnetic or ultrasound flowmeters are selected based on accounting of estimated wastewatering.
To establish wastewater consideration in samotane pipelines is a more complex task. Open or closed channels are characterized by the movement of uncleanness by gravity under the action of gravity with low speed.
The devices that measure the liquid only provide indications for the further calculation of the volume of wastewater, taking into account the data cross section of the channel. For open channels, lever-pendulum flowmeters are used.
More accurate results give the devices of the second form, measuring according to the principle of "Speed \u200b\u200bSpeed". The level of fluid in non-pressure channels does not have a constant value. In a private house, plums can occur periodically, there will be a discharge of the plums, therefore, the data on the flow area, its speed over the time intervals are used.
To measure the speed in the non-pressure closed channels use ultrasound and electromagnetic flowmeters. Specific models are selected depending on the diameter of the pipeline.
The wastewater accounting node is a set of measuring wastewater costs, well, to accommodate accounting devices and their maintenance, and the segment of the pipe on which measurements are made. Measurement tools consist of a primary converter (sensor) and a secondary converter, which takes processing, storage and displays the measured information. The well is constructed specifically on this section of the pipeline. The pipeline must be straightforward in the segment of measurements of wastewater.
Before choosing a flow meter type requires an assessment of the need and appropriateness of setting the metering device and choose a place to install the instrument.
With the device of the accounting node in individual build, the place should be selected to the connection point with the total sewer.
When measuring instruments, the instrument must record the flow values \u200b\u200bof the flow rate over the entire cost range for the existing diameter of the pipeline. The accuracy of measurements should be high, an error is allowed not more than 5%. The accounting system should accumulate all the information, provide information on the total storage amount, measurement periods and downtime. The power supply of the flow meter should be uninterrupted with a spare power source.
The pipeline portion where the accounting device is installed must be straightforward. The flow meter follows the lower part of the individual sewer network, where the maximum filling of the pipeline is located.
The project is required for each node, which is consistent with departments and organizations serving sewage networks. After receiving all permits and project execution, the contract for subscription services is concluded.
Ultrasonic wastewater flow meter in action:
       |
|
Release with already ready-made ultrasonic transducers for diameters: 15, 25, 32, 50, 65, 80, 100, 600, 200, 200, 500, 350, 200, 500, 1000, 200, 500, 1000, 200, 500, 1000, 2 MM!
Specially created and ideal for the use of water volokinals, on the KNS, facilities housing and communal services, energy, industry!
For accounting for volume and consumption of pressure of household and wastewater, chemical waste, fecal waste, in the CNS, etc. apply exactly the same sets of flow meters as for water metering
The flow meter meter for the sewage should be established by following the following rules:
ATTENTION! The main conditions for the correct operation of the US-800 water flow meter are to complete the cross section of the UPR liquid.
In order to avoid possible errors Measurements and failures due to the presence of gas or air inclusions must be followed by the following recommendations:
Galvanic isolation The primary converter (pipes) from the electronic unit. The only flow meter in Russia !!
All products are certified!
| US-800 flow meter execution | EB serves 1 single-rolled UPR, one channel of measurement, 2 sensors (1 beam) are embedded |
EB serves 2 single-collar UPRs, two independent measurement channels in one electronic unit, 2 sensors (1 beam) are embedded, convenient in multichannel systems, in compound heat meters |
EB serves 1 two-beam UPR, one channel channel, 4 sensors (2 beams) are embedded on the UPR, it is distinguished by an increased accuracy of 0.5-1%, requires a minimum of direct sections during installation. |
 |
 |
 |
| Do from 15 to 1400 mm | Do from 15 to 1400 mm | Do from 50 to 1400 mm |
The electronic unit has a large LED (segment) indicator that is displayed consumption (m3 / h), volume (m3), time (hour) trouble-free operation of the device. Additionally and on request:
| Possible digital outputs from the US-800 electronic unit performances 11, 13, 21, 23, 31, 33 |
|
RS485 digital interface Support data protocols for RS485: DCON, MODBUS (on request) |
|
| The load capacity of the electronic unit allows you to combine up to 32 pcs of flow meters into one network segment. When using RS485 / RS485 repeaters, a network can be expanded to 256 pcs of flow meters. |
|
The ultrasonic consumption converter UPR (with already installed PEP sensors) is a pipe segment, on the ends of which two flanges are welded, and the PEP sensors are located in the middle part. On pipes with diameters 250-2000 mm, kits without Ex-KMF are also offered - with KMUC-set motors and mounting parts for cutting on the pipe (or manufacturing UPR) at the place of operation. The kit with KMC requires a qualified installation!
UPR or KMF required in the kit!
UPRs are two species depending on the number of measuring rays: single and two-beam.
Also differ in ways to attach ( flange or under welding) and manufacturing materials 12x18N10T (stainless steel) and ST20 (Chern.stal): Seetablitsa below.
| Execution of ultrasound consumption converters | ||
| Single-headed cutting pairs of sensors in diameter.
|
Double-beam Cut two pairs of sensors in chords. |
Note: Max pressure, max temperature, degree of dustcakers. |
| UPR 15, 25 N'TZH.12X18N10T, threaded connection  |
1.6 MPa, +120 ° С, IP65 |
|
| UPR 15, 25, 32, 40, 50, 65 |
UPR 50, 65, 80, 100 N'TZH.12x18N10T, flange connection  |
1.6 MPa, +120 ° С, IP65 |
UPR 80, 100, 150, 200, 250, 300 |
UPR 150, 200, 250, 300 N'TZH.12x18N10T, flange connection  |
1.6 MPa, +150 ° С, IP65 |
 |
UPR 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1200, 1400 Steel20, flange connection  |
1.6 MPa, +150 ° С, IP65 |
UPR 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1200, 1400 |
UPR 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, 1200, 1400 Steel20, Blank for welding  |
1.6 MPa, +150 ° С, IP65 |
| KMCH Somnolch. 200-2000
|
KMCH bicycle 200-2000 bestuker version, UPR is not included. Steel20, sets of mounting parts (bobs, nuts, sensors) for the installation on the pipe of operation
|
2.5 MPa, +150 ° С, IP65 |
|
Notes: 1) All flange compounds can be equipped with response flanges and fasteners (for additional pay). Material of all flanges Steel20, flanges according to GOST 12820-80. Additionally and on request: |
||
Connecting cable from EB to UPR pipes (by order up to 500 meters).
Coaxial cable 50 ohms, like RK-50, for connecting UPR and EB.
Mark cable RK-50-2-11.
When ordering the cable, pay attention to the number of sensors for Exhibit!
The cable is required in the kit!
Kit accompanying technical documentation: passport, instruction manual and installation, copies of certificates.
| US-800 wastewater flow meter measures consumption depending on the diameter of the conditional passage of the UPR in accordance with the table | |||||
| Do, mm. | Volumetric flow, cubic meters / hour | ||||
| Q Max Maximum | Q p1 transition t | Q P2 Transitional T\u003e 60 ° С | Q min1 minimum T. | Q min2 minimum T\u003e 60 ° С |
|
| 15 | 3,5 | 0,3 | 0,2 | 0,15 | 0,1 |
| 25 | 8 | 0,7 | 0,5 | 0,3 | 0,25 |
| 32 | 30 | 2,2 | 1,1 | 0,7 | 0,3 |
| 40 | 45 | 2,7 | 1,3 | 0,8 | 0,4 |
| 50 | 70 | 3,4 | 1,7 | 1,0 | 0,5 |
| 65 | 120 | 4,4 | 2,2 | 1,3 | 0,65 |
| 80 | 180 | 5,4 | 2,7 | 1,6 | 0,8 |
| 100 | 280 | 6,8 | 3,4 | 2 | 1 |
| 150 | 640 | 10,2 | 5,1 | 3 | 1,5 |
| 200 | 1100 | 13,6 | 6,8 | 4 | 2 |
| 250 | 2000 | 17 | 8,5 | 10 | 5 |
| 300 | 2500 | 20,4 | 10,2 | 12 | 6 |
| 350 | 3500 | 23,8 | 11,9 | 14 | 7 |
| 400 | 4500 | 27,2 | 13,6 | 16 | 8 |
| 500 | 7000 | 34 | 17 | 20 | 10 |
| 600 | 10000 | 40,8 | 20,4 | 24 | 12 |
| 700 | 14000 | 47,6 | 23,8 | 28 | 14 |
| 800 | 18000 | 54,5 | 27,2 | 32 | 16 |
| 900 | 23000 | 61,2 | 30,6 | 36 | 18 |
| 1000 | 28000 | 68 | 34 | 40 | 20 |
| 1200 | \u003d 0.034 x Du x Du | \u003d 0.068 x Du | \u003d 0.034 x Du | \u003d 0.04 x Du | \u003d 0.02 x Du |
| 1400 | \u003d 0.034 x Du x Du | \u003d 0.068 x Du | \u003d 0.034 x Du | \u003d 0.04 x Du | \u003d 0.02 x Du |
| 1400-2000 | \u003d 0.034 x Du x Du | \u003d 0.068 x Du | \u003d 0.034 x Du | \u003d 0.04 x Du | \u003d 0.02 x Du |
| Brief technical characteristics of the flow meter for wastewater (sewage meter) | |
| Criteria for filling pipeline liquid | should always be filled with liquid at the measurement site |
| Temperature of the measured fluid | 0 ... + 120 (+150) ° С |
| Pressure fluid in the pipeline | up to 1.6 MPa |
| Temperature UCRs at the installation site EB | +5 ... + 50 ° С |
| Temperature OKR. Credients at the installation site | -40 ... + 60 ° С |
| EB / EB / UPR dust | IP65 / IP65 (IP68) |
| Length of rectilinear sites (single-rolled UPR) 15-2000 mm | 10 do up and 3 doom after |
| Length of rectilinear sites (two-beam UPR) 15-2000 mm | 5 doo before and 1 do after |
| Supply voltage | 220V (18-24-36 in post.tok Stepezakaz) |
| Indication | 9 acquaintance, segment indicator |
| Maximum power consumption | 7 W. |
| Length of connecting cables from UPR to EB | up to 200 meters (up to 500 special price) |
| Intermediate interval | 4 years |
| Full average service life | 25 years |
| Guarantee period | 18 months |
The traditional method of wastewater accounting is the definition of their volume on the meter on water pipe. The logic of this approach is simple - it is believed that most of the water entered the point of the water treatment is in the sewer. However, this is not always the case.
Part of the water can be spent on watering or other needs without a subsequent removal into the sewer system. Such a device, as a sewage meter, is extremely useful in enterprises, where the amount of wastewater entering the sewage system is significantly less than the volume of the water received.
Modern metering devices are high-tech products with the presence of electronic components. These devices provide accuracy and reliability of measurements.
Calculations are carried out in open channels or pipelines in which chemically aggressive substances and suspended particles may be present. Therefore, all the drainage devices are constructively adapted to work with aggressive and heavily polluted liquids.
On the principle of operation, sewage meters are divided into two types:
|
|
The range of wastewater flow meters includes the following types of devices:
In addition to stationary measuring instruments, portable devices are used, which are used to temporarily replace the flow meters. Portable counters are equipped with ultrasonic sensors. Devices can work all day from the battery, and at night put on recharging. Using the adapter, their uninterrupted nutrition can be organized.
Before choosing the required type of flow meter, you need to evaluate the feasibility of conducting such measurements and choose a place to mount the device.
In cases where objects that are manufacturers of wastewater are located in the zones of tight construction, the organization of accounting is often impossible. To confirm the technical inability to install the flow meter, a special conclusion is issued.
If the decision to install the flow meter is accepted, the type of device must be determined depending on the features of the object. Typically, the flow meter is installed on existing networks in special wells.
Existing viewing wells available in the networks are inappropriate. This is due to the fact that observation wells are placed in places of rotation of the pipeline or changes in its position.
This contradicts the rule that measuring instruments should be mounted on a straight line.
When organizing accounting and can be encountered with two problems that affect the accuracy of the measurements carried out, these are subranges and casing.
Causes of the appearance of subpoits:
Slores can be eliminated by cleaning waste sewage, and the rest of the problems solve repair work.
Causes of Holy:
In order to avoid the inaccuracies of measurements, before carrying out the calculation of the volume of wastewater, it is necessary to take care of bringing the system in full order.
To obtain correct results of drafting results, you must:
Wastewater B. sewer systems Can be moved along pressure and free-free networks.
In the pressure networks of the fluid move under the influence of pumps, and in the non-pressure - gravity, due to the bias of the pipeline.
Measuring the amount of wastewater passing along the pressure networks does not represent difficulties. In this case, you can use instruments operating on the principle of water meters.
Differences of the working conditions are the presence of large amounts of pollution in the wastewater and lower water current. The selection of flow meters is carried out by taking into account the estimated wastewater consumption.
It is much more difficult to take into account the wastewater moving in gravity. The movement is carried out with a slight speed under the influence of gravity forces.
In this case, use:
The first type of flow meters is used for U-shaped and pipelines. In the channels of different form use standard waterproofs.
For them, the formulas for recalculating the flow level in their consumption were developed.
You can measure the real level of fluid in the sewer tube with an outer echolocation sensor or submersible device that takes into account pressure drops. When comparing the results of these two dimensions, you can get accurate information about wastewater volumes.
The use of devices that simultaneously take into account the level of fluid and the flow rate allows to obtain the highest possible data on the amount of effluents entering the sewer system.
Measurement of fluid flow (q) in the pipeline or channel cannot be performed directly. For its calculation, the formula Q \u003d ṽ * A is used, where A is the area of \u200b\u200bthe cross section of the stream, and ṽ is its average speed.
In this case, the main and difficult task is the correct determination of the average speed ṽ, since the area of \u200b\u200bthe cross section A is determined on the basis of the channel form (which can be taken from the construction documentation, or is measured when creating an accounting node) and the flow level, the measurement of which can be performed different ways And, as a rule, no problems.
Currently, there are several methods for measuring wastewater consumption in non-pressure pipelines and a large number of different types of equipment for solving this task. These methods include:
There are some other types of wastewater meters, but they are not much common due to their obvious deficiencies when working in drains.
This, for example, electromagnetic point flowmeters whose sensors produce measurement in the localized flow area. Their disadvantage is that electromagnetic point sensors are capable of working continuously in relatively clean water.
Also there are devices that determine the flow rate based on the measurement of the rejection angle of the pin (lever) immersed in the stream. This method is quite simple, but any dirt on the flow surface, especially in hoking fecal drains (hair, rags, etc.), immediately violates the testimony.
To determine the applicability of the above systems in various conditions, consider their main advantages and disadvantages.
The main advantage: simplicity and ease of installation and maintenance, which are determined by the fact that the contactless sensor is above the water surface and does not contact with the drain. The device measures the speed of the surface drain, which is a significant advantage compared to simply level gauge.
However, the small distribution of these systems today both in Europe and in Russia, as well as a sufficient number of negative feedback, says that they have and disadvantages. The main disadvantage is a very high flow measurement error that gives up to 30% and even up to 50%. A large error is determined by the strong dependence of this method of measurement on the state of the flow surface (from waves and ripples), as well as the absence of a unambiguous communication between the measured velocity on the surface and the average speed, which determines the volume flow rate of the liquid.
Applying radar flowmeters are recommended only in cases where there is no possibility of installing more accurate (submersible) devices - Doppler or cross-correlation. In addition, radar flowmeters are quite expensive today, and their use on nodes of commercial metering of water with low consumption is impractical.
In addition to the above disadvantages inherent in radar contactless systems, the problem of the complete absence of information about the flow rate is added when using level gauges for determining the flow rate.
Such instruments can relatively adequately work in the absence of backups. But guarantee the absence of subpoits is very problematic. If there are not even at the time of installation of the equipment, they may unpredictably appear over time. Any starting blockage or an extraneous object in the channel leads to the appearance of a backpage. If the pipe from the enterprise drops the estones in the city collector, and the collector works in a large fill mode, and the backup also occurs. If there is a subjo, the error of this method of measurements can reach hundreds of percent. If the water in the collector is still motionless, and the level remains large due to the backpage, the error strives for infinity.
In addition, the use of ultrasound level gauges is impossible in the presence of foam, steam, fog, intense precipitation, big waves, etc.
The unconditional advantage of flow measurement systems based on levels is their low cost, as well as simplicity of installation and maintenance. Apply this method is recommended either for technological (non-commercial) needs, or for commercial accounting on pipes and channels with a low flow, when even a large error of the device does not lead to large financial losses.
Submersible Doppler flow meters produce measurement of particle speeds in a stream based on the Doppler effect (measuring the difference in the frequencies of the emitted ultrasonic signal and the signal reflected from the moving particle).
The problem is that in different layers, the particle flows are moving at different speeds. Closer to the bottom or walls, the particles are moving slower, closer to the surface - faster, on the surface again slower. The distribution of velocities depends on many factors, including from the size and nature of bottom sediments, the roughness of the walls, character, speed and level of stream, etc.
Doppler sensors are not able to determine at what level particles are located, the speed of which they measure. The average speed in this case is defined as a product of the measured velocity to the calibration coefficient "K".
In this case, the calibration coefficient is usually selected according to the tables depending on the material of the pipeline wall or channel, time from the start of the operation of the channel, etc. This uses a significant assumption. Either the coefficient is determined during the calibration process during installation. But, in this case, it should be borne in mind that the actual dependence of the average speed from the measured is a nonlinear function from speed and level, i.e. Calibration, made at some hydraulic characteristics, will not be correct at other characteristics. In addition, the testimony of Doppler flow meters strongly affects the level of pollution of the flow (the amount of suspended particles per unit volume).
The Doppler Measuring Method gives significantly more accurate results than the use of level gauges or contactless radar flow meters, but at the same time its error in some cases can be 20-25%, with accurate compliance with all the requirements of the operating manual (which is confirmed by a number of comparative tests). Nevertheless, in some cases, depending on specific hydraulic conditions, Doppler flowmeters may produce good accuracy (2-5%).
Translation of the original mode of operation of the pipeline in pressure is quite simple and beautiful decision For pipes of small diameter.
 |
 |
 |
After installation in the well of the non-per-pipe pipeline, the pipe covered up, the pipeline is completely filled and goes into the pressure mode. Measuring the flow rate in the pressure pipe is a simpler and spent task. This can be done both ultrasound sensors and electromagnetic flowmeters, the error of which can be 0.5-1.0%. However, in some cases, dirty stock in the bend of the pipe bending can form blockages - as a result, the error is growing due to deposits (in proportion to the growth of sediments) and after a while the node becomes inoperative. The daily cleaning of the pipe at the site of the accounting node is unlikely to be acceptable for the user. In addition, this method is difficult to implement and sufficiently dear in the pipes of large diameter. It is usually used in pipes with a diameter of less than 300 mm.
The cross-correlation method was developed and patented by Nivus GmbH in 2000. This method is sometimes confused with the Doppler method, although it does not have a direct relationship. In the cross-correlation method, the signal frequency change is not analyzed when reflected from moving particles, and ultrasound photos obtained with a frequency of 500 to 2000 units per second are compared.
Based on comparisons of these ultrasound photos, the movement of particles in each layer of flow per unit of time is determined, i.e. The speed of movement of all layers of flow is determined. Thus, the average speed is precisely calculated on the basis of the direct velocity measurements of the flow layers. In this case, neither pre-calibration is not required, nor the accounting of the wall roughness by entering table (theoretical) coefficients.
This type of flow meters is designed primarily to measure in relatively pure threads, since the accuracy of their testimony strongly depends on the uniformity of the medium. This type of instruments are often used to measure the consumption of pure drinking water, or on water intakes. In part of the effluent, they are usually used on reset channels of cooling circuits industrial enterprises, as well as for purified water at the output of wastewater treatment facilities. Their advantage is the ability to measure very wide channels - up to 100 meters or more. Time-pulse flowmeters are available with mortise or overhead sensors for pressure pipes, and for non-free pipes - in the form of tubular or wedge-shaped sensors, or hemisphere.
 |
 |
If the installation of contactless sensors of levels and radar flow meters is all sufficient (simplicity of installation is their main advantage, to the detriment of measurement accuracy), the installation of submersible sensors often requires special technical solutions. In the sampling pipes with a diameter of 200-800 mm, Doppler and cross-correlation sensors are set, as a rule, on the spacer mounting ring, which ensures the minimum installation time with reliable fixation.
In the pipes with a diameter of over 800 mm, the plate with the sensor is attached to the pipeline wall.
When installing in particularly dirty water, such as industrial or fecal sewage, you need to closely monitor the laying and fixation of the cable, special in the bottom of the pipe. In addition to the fact that the poorly fixed cable leads to the accumulation of hair, dirt and cloths on it (with the possibility of a subsequent blockage or separation of the entire structure of the stream), it can hang under the action of the stream and move when friction about the construction design. When fastening the metal plates to the wall of the pipe of a large diameter, the shape of the head of the screws and many other technological details is of great importance.
A serious problem is to install submersible sensors in a deep stream, especially at high flow rate and the impossibility of a temporary stopping stream. This can use diving work or work with a minimum flow level (at night, etc.). However, there are also special technical solutions that allow not only to lower the sensors into a deep stream, but also to extract them from there without the help of divers for calibration and maintenance. The figures below show options for mounting sensors on metal structures that can descend into the channel and removed from it.
In addition, sensors can be installed on the floats "upside down". This not only facilitates the installation of sensors in deep channels, but also makes it possible to produce accurate calculations with variable bottom sediments (in cases where bottom sediments depend on the amount of precipitation dropped, for example), since the ultrasonic level gauge is built into the sensor will measure the flow level from the surface Before the actual surface of the bottom with deposits.
Can be mentioned about additional features Cross-correlation flow meters for measuring wide streams. This type of flow meters allows you to connect several speed sensors located on the bottom of the channel, or on the bottom and on the channel walls and, due to this, to obtain the speeds of the speeds not only at the depth of the stream, but also in width. This ensures high measurement accuracy in wide channels.
The most serious problem when using submersible sensors is the ability to lose their performance as a result of pollution when working in a dirty sewage drain, or destruction in the presence of rolling stones in the stream and other heavy items. At the same time, Russia's waterochannels are particularly serious about this issue, because they consider sewer pipes In our country, the most dirty. But it is not so. Submersible sensors are used worldwide, not only in well-groomed pipes in Germany and Switzerland, but also in India and in other countries where the sewage is not cleansing domestic.
Ultrasonic sensors used are specifically designed for heavy working conditions and do not lose when driving, as the wet Il is well missed ultrasound.
When the sensors are coated with a layer of rags or material, opaque for ultrasound, flow meters of leading manufacturers do not give incorrect readings, and signal an error and need for cleaning. To reduce the probability of clogging, the sensors are usually installed at the bottom (not at 6 o'clock), but with some displacement (for example, for 4 hours or 5 hours).
Apply the installation on a small elevation (on a special stand) and a number of methods for minimizing the problems created by mud.
To protect against rolling stones and other solid items that can break the sensor body, use the metal protection of a special form.
Another problem task is to measure in flows having a low level at some time. This leads to the fact that water does not cover the sensor and does not allow to measure the speed. The above has already described the possibility of transferring the non-pressure flow into pressure by using the pipe bent up. Small dams can also be used to raise levels. At the same time, the flow remains non-per-level, but the level rises.
Among the flow meters certified and used in Russia, you can note the following manufacturers:
Cross-correlation appliances supplies Nivus GmbH.
Doppler flowmeters supply several foreign and a number of domestic companies; Among the overseas can be noted Nivus (OCM-F), ISCO, ADS, Hydreka (Mainstream); Domestic manufacturers of "take-off" and "Dnipro" are still not recommended to acquire their Doppler meters, while to measure the flow in open channels, they are advised to put more familiar levels of their production.
Radar contactless flow meters with a surface flow speed measurement function offer Nivus (OFR), Flowtronic (Raveneye), HACH (FLO-DAR). ISCO offers a contactless laser flow meter.
Devices for transferring non-pressure flow into pressure offline Nivus (Profiler), Flow-Tronic (Sewer MAG) and domestic enrime manufacturer (Stockmer).
Time-pulse flow meters for channels offer Nivus, Accusonic and Seba Hydrometrie.
Among the levels with the function of measuring the consumption are the most popular manufacturers of the signur (Echo-P), take off (RSL), Dnipro and many others. You can pay attention to the fully autonomous Sonicsens level gauges that run from batteries from three to five years and transmitting information about the level and expenditure over the GSM wireless communication channels.
Cross-correlation sewage accounting devices today are the most accurate, reliable and stable from all flow meters available in the market. But the price is higher than that of Doppler flow meters and, moreover, level gauges. If you are dealing with a small pipe, with a small stream and if annual payments for water on this node of accounting is significantly lower than the cost of a high-quality flow meter, then it may be more profitable for you to use a cheaper (albeit less accurate) system - level gauge or doppler. It is interesting that the Doppler wastewater flowmeters, Nivus holds quite loyal prices, below most of the imported suppliers, due to the fact that the main focus of Nivus makes the most reliable cross-correlation systems. As for the channels with a large consumption, then for them the cross-correlation method is currently the best.
Today there is enough big choice Wastewater accounting devices that differ in price and quality. And if you are faced with the task of buying a counter for the original industrial, hosbert or storm sewage, either pipes and canals of water intake and water supply, then for each case of application you can choose your own option. At the same time, the installation of wastewater accounting nodes is better to trust specialists, since the accuracy of the testimony and the duration of their operation depends on the proper installation of instruments.
The Russian Law on Energy Saving requires enterprises and housing facilities to organize wastewater accounting. Many have encountered such a question for the first time. First you need to decide on the term ourselves and learn how to form their education and the place where they go.
Wastewater is contaminated with industrial waste and household waste of water, as well as those that are formed as a result of atmospheric precipitation falling within industrial facilities and settlements. Streams from the territory are removed using the sewage system. This is a whole complex of engineering equipment, structures and sanitary activities that ensure the collection and the discharge of wastewater, as well as their disinfection and cleaning before discharged in reservoirs or disposal.
There are two types of sewage:
The internal system is located inside the construction and buildings. It serves to collect and output polluted waters into the outer sewer network, in which the effluent is transported by the territory of industrial facilities and settlements. The internal sewage includes elements such as taps, sanitary devices, risers and issues from buildings.
Elemental sewage elements include pressure and samotane pipes, sewage treatment plants and sewer pumping stations, simply speaking, CHS.
The sewage system implies a separate or joint sewage of such categories: industrial, household and rain. The sewage system itself can be separate and glusted. With a separate system, conditionally clean industrial and rainwater are removed on the same network, and production and households on the other. The public system on the total network of channels and pipes will assign all of the above-described categories of wastewater.
Accounting is engaged in government agencies. Installation, replacement and verification also controls the state. Subscribers are required to provide representatives with access to plumbing and sewer instruments. Vodokanal can not do this for free. Therefore, drainage services are paid in the same way as water supply services, that is, in proportion to the volume of water assigned.
From the above, it can be concluded that with all the cheapness (costs for the organization of contaminated water, there are no stocks of effluent is approximately. It is not able to take into account the features of the consumer who are quite seriously influenced by the "Stream / Consumption" ratio, both in both parties and on the other side. It should also be remembered that the sewage hits both consumed cold and consumed hot water. Supplier of such waters is most often different companies, while wastewater falls completely onto the water volokanal.
Bridal, rain, gone to the ground with pipeline accidents, fused by the sewage and evaporated water are "disturbing" factors. It is because of them that the method "Consumption / Strook" works normally only in small consumers, for example, in the residential sector, which "traditionally" uses water. In other cases, it is necessary to organize accounting using instruments.
Accounting for polluted water in some cases will be beneficial to the side that drains, and in some - the side of the drainage. But still account will be "transparent" and objective in any case.
It has already been mentioned that wastewater is transported under pressure and non-pressure pipelines. The accounting system of both systems is somewhat different. Measure the volume of pressure supplements is simple enough. The measurement of the volumes of water supply (ordinary) water from the waste measurement is only the fact that in the second case the flow rate is much smaller, and the degree of contamination is much larger.
As a rule, accounting devices are installed at the output pumping stations sewage. Most often, ultrasound or electromagnetic flowmeters are in their roles. They are selected according to the range of measured expenses. Ultrasound devices You can apply with overhead sensors. In order for them to provide stable operation (and reduce the load of pumps), automatic air vent and check valves should be used.
A completely different, more complex task is to account for non-patlas. In this case, there is a blank tube or an open channel by which water flows at low speed under the action of gravity.
Especially for this option, the method of the variable level was invented. In this case, the level gauge is used as a flow meter. It recalculates accounting information about the measuring section with the "level level". In the role of section, Parshal and Venturi trays and Venturi trays are performed. Also applied water, having standardized dimensions. For them, the "Level-Consumption" formulas are obtained by semi-empirical path. This method works in U-shaped and non-pressure pipelines, and in these cases, water and trays are not needed. The described method is regulated by the documents of the State Standard.
However, claims to such a way are available. They appear due to the fact that the point of reference in this method is the results of a pre-calculated pressure-consumable characteristics of the pipeline, tray or waterproof. More precisely, the preliminary calculation will be completed, the more accurate the device will operate in the future. To determine the characteristic of the non-pressure pipeline or the U-shaped channel, the flow rate of the fluid (provided that the filling level is known) should be determined experimentally. Measurement is carried out on the eye.
For example, you can use a sliver to be thrown into the channel, and wrist Watch. The error of such an experiment is ahova. Therefore, there is another way - the Formula of the Swazy. Here, the coefficient of the wall roughness is taken and the pipeline construction slope. But these quantities can be called theoretical, because the real slope does not always correspond to the specified in project documentation, And the roughness of the walls and its coefficient is constantly changing in the process of using the pipeline. Despite this, preliminary calculations are entered into the device. If an error is made in the source data, this may result in unreliable accounting. In many cases, this error can not be noticed. That is why for designing and installation of systems for the accounting of non-patural drafting, it is necessary to attract professionals.
Russian enterprises "Signur" and "take-off" produce devices that carry out the method of variable level. This is the flow meters of Echo-P-02 and "take-off-RSL". The level is measured by the contactless method due to the ultrasonic sensor, which is placed above the pipeline or channel.
Each device has its advantages and disadvantages. Benefits:
Disadvantages:
The price of such an instrument is approximately 45,000 rubles.
The flow meter "take-off-RSL" has the following advantages:
Despite all the advantages, "take-off-RSL", like any other flow meter, has both disadvantages:
The cost of such a flow meter is about 60,000 rubles.
In addition to domestic manufacturers, flowmeters produce foreign companies. From foreign devices for measuring costs in non-pressure pipelines and open channels, there are devices implementing the "Speed \u200b\u200bSpeed" method. For example, TELEDYNE ISCO products. In such devices, the sensor is placed on the bottom of the channel and, using a pressure sensor, measures the water level above itself and the flow rate (using the Doppler method). The channel parameters should be in advance to the instrument memory. It compares this data with real-time information on the level of filling, after which the flow rate and flow rate is calculated. The main disadvantage of this method is its price, which is much higher than that of Russian flow meters.
It should be noted that for domestic, and for foreign appliances, the main "enemy" will be poured and the formation of a precipitate in the measured place. In this case, the error is increasing. Therefore, the flow meter, like the place of its installation, requires regular maintenance.
From the foregoing, you can draw conclusions. Today, wastewater accounting is a fairly relevant task. It can be solved various methods. And if the pressure systems are not problematic, then non-perm can be calculated in several ways. Consumers with a small scale of wastewater and the uniform ratio of consumed and polluted water can be used by the estimated method. The ratio coefficient is determined empirically. But large consumers with a changing or non-obvious ratio "Consumption / Stocks" should be acquired by instrument accounting. The devices that implement the variable level method will be less expensive. But the devices "Square / Speed" will cost much more. In both cases, accounting units must install professionals. They also require permanent service.
