RF Government Decree No. 776 of 09/04/13 obliged homeowners and entrepreneurs to introduce control over wastewater accounting. Ultimately, the event should lead to a rational approach to the use of natural resources and a reduction in water use charges. By default, the volume of waste water is taken equal to the number of cubic meters of hot and cold water, determined by meters or by accepted standards. Studies show that real consumption is higher. Homeowners can use the water for household needs: watering flower beds, caring for animals. A sewerage meter in a private house will determine the actual amount of wastewater entering the sewerage system.
Types of flow meters for waste water
There are several types of sewage water meters, which have different devices, technical operating conditions and designs.
Electromagnetic devices
They are built on the principle of transformation of the electromotive force obtained by the interaction of the flow of an electrically conductive fluid with the generated electromagnetic field. The digital signal that determines the meter reading is directly proportional to the water flow rate.
Benefits:
- reliability;
- high measurement accuracy;
- simple maintenance and installation;
- the ability to take readings when the medium moves in two directions;
- work without loss of pressure and vibration.
They are used in industrial production, energy, petrochemical industry and other sectors of the national economy.
Lever-pendulum meters
Measurements are carried out in two parameters:
- liquid level;
- flow rate.
The principle of operation is based on the movement of the float mechanism in contact with the measured medium. The vertical displacements of the float are converted into signals and transmitted to various measuring devices, the flow velocity is measured using a rotary vane.
The main application of meters of this type is found on discharge open and closed channels, with their use they monitor the level of the liquid.
Ultrasonic water meters
The principle of operation is based on the analysis of acoustic data, which are taken when the flow passes through ultrasonic vibrations. Two parameters are used for measurement:
- cross-sectional area;
- travel speed.
They are widely used in sewage treatment plants, local, gravity and open sewerage systems, in free-flow installations with large-diameter pipes. The service life is up to 10 years. High accuracy with an automated safety system allows the devices to be used in various industries.
Main advantages:
- the ability to operate water meters in closed pipelines without free access to the regulation of the device;
- use of wireless communication;
- remote access when taking readings;
- saving measurement data on removable media.
Ultrasonic devices need constant supervision and maintenance. In overhead flowmeters, it is necessary to replace the gel.
Vortex counters
Based on the measurement of pressure drops that occur when a triangular object is immersed in a gas or liquid medium.The emerging eddies are directly dependent on the flow rate. A zone of reduced pressure is formed in the vortex flow. The difference between a high and a low value creates a difference in the parameter, which is recorded by the meter. The rate of change of the monitored signal allows the flow rate to be calculated.
Advantages of vortex meters:
- no moving parts;
- ease of execution;
- the accuracy of measuring parameters regardless of changes in pressure and temperature of the medium;
- resistance to mechanical stress;
- stable operation in highly polluted environment.
Disadvantages:
- pressure loss;
- sensitivity to noise and vibration;
- unreliable indicators at a low flow rate.
Vortex devices are not effective in pipes with a small cross-section (up to 150 mm) and with a large diameter (over 300 mm).
There are also induction, radar and mechanical ring devices. But they did not receive much distribution.
Criterias of choice
The consumer is interested in the optimal ratio between the cost of the device and the possibility of generating income with an accurate determination of the volume of effluents. Lever-pendulum meters have a low cost. They are able to work with sufficient accuracy even in silted pipes for a long time, but they require verification every 2 years.
Portable devices based on ultrasonic technologies are used to simultaneously control the wastewater flow rate. Their advantage is easy installation and accuracy, which are offset by a fairly high cost.
Features of installing the meter on drains
The meters can only be installed by qualified specialists, since if the technological conditions are violated, the readings of the water meters will not be considered reliable. This will lead to additional monetary losses.
The selected device must correspond to the type of sewage system and the diameter of the pipe, and also have the necessary blocks for its operation.
Instrument installation requirements:
- installation is carried out according to the existing instructions;
- the section of the inner cavity is filled with liquid;
- the dimensions of straight sections of the pipeline at the inlet and outlet of the flow meter are observed;
- the device is correctly located inside the pipe section;
- install the meter on a straight section of the gravity sewage system at the lowest level with a deviation of no more than 25 degrees;
- it is not allowed to install near bends, at high points and descending sections of the pipe system.
Compliance with the requirements will reduce payments for sewage. This statement is especially true for owners of private houses. The location of the device should be convenient for field service.
Possible problems using the device
The forums voiced problems with the use of the RSL-212 water meter. During installation, the configuration was not read, it was not possible to enter the settings. The error may consist in overwriting the settings of the primary meter. Eliminated by using the "communication setup" function.
When air enters the section of the device, the indicators are distorted. The complexity of setting up water meters is noted: two devices installed side by side often show different values.
The cost of sewerage meters
The most popular are the Vzlyot devices, as they are certified. Designed for use in free-flow pipelines. The price of the sewage meter Rise RSL is 74,000 rubles.
Dnepr 7.01.11-1 is used in free-flow collectors. Price: 44000 rub.
ECHO-R-02 ultrasonic flow meter measures the volume of wastewater in free-flow pipelines with diameters from 100 mm and in open channels. The meter is intended for commercial accounting. Price: 45 600 rub.
Ultrasonic portable water meter AKRON-01 is used to determine the instantaneous value of the parameter in pressure sewer pipelines. Price: 41,000 rubles.
