Sewage Flow Meters

Sewage Flow Meters- Wastewater Flow Meters

Sewage flow meter, also known as a wastewater flow meter. The sewage flow meter measures the flow of various sewages in pipes and open channels. Common sewage flow meters are magnetic flow meters, non-contact ultrasonic flow meters, etc.

Industries like wastewater, river water, industrial gas.

What is wastewater flow?

Sewage flow or wastewater can be a pain to accurately measure. The environment is corrosive and humid. While the flow itself can experience wide swings due to inflow and infiltration. Wastewater is usually carried in non-full open channel pipes.

So, all the flow measurement instruments suitable for Sewage flow are called Sewage flow meters, or wastewater flow meters.

Here you can find a Sewage flow meter to measure the flow of wastewater for your application.

How is wastewater measured?

Magnetic flow meters

The electromagnetic flowmeter is based on Faraday’s law of electromagnetic induction. That is, the measured medium flows perpendicular to the direction of magnetic lines of force. Thus generating an induced electromotive force in a direction perpendicular to the flow of the medium and the lines of magnetic force.

Extended reading: Industrial Magmeters

The induced electromotive force is proportional to the measured medium flow, and the instantaneous flow rate can be obtained by using the flow rate, and the cross-sectional area of ​​the pipe.

The conductivity in water is one of the prerequisites for the electromagnetic flowmeter to work properly.

The sewage contains a large number of impurities and salt and has a certain conductivity.

Therefore, the electromagnetic flowmeter can be used for sewage measurement.

For pure water, it cannot be measured with an electromagnetic flowmeter.

The advantages of the electromagnetic flowmeter are high precision, stable measurement and wide application range.

The electrode and the inner lining can be selected according to the medium, and can also be used for measuring work in a bad medium.

The disadvantage is that it is easily interfered by electromagnetic waves, and the diameter of the pipe is larger.

The more expensive the price, the larger the diameter of the electromagnetic flowmeter is not easy to disassemble, and the maintenance is difficult.

Guess you like: Magnetic Flow Meters technical guide|What is &How they work? 

Ultrasonic flowmeter

Ultrasonic Flow Meters

The working principle of the ultrasonic flowmeter (Best Guide to Ultrasonic Level Transmitter) is that, by means of the time difference measurement principle. A pair of ultrasonic probes transmit signals through the intermediate medium to the other side of the tube wall and are received by the other probe. And the other side of the probe also transmits a signal to be the first one.

Extended reading: Ultrasonic Insertion Flow Meter for Lined/Large Pipes

The probe is received. In this process, since the signal delivery time is affected by the medium flow rate, there is a certain time difference.

Based on this, the ultrasonic flowmeter calculates the corresponding flow value by means of the relevant formula.

In general, ultrasonic flow meters can be divided into two types: external clip type and plug-in type.

If the length of the straight pipe before the flowmeter does not meet the installation requirements, a multi-channel ultrasonic flowmeter can be installed.

Compared with the electromagnetic flowmeter, the installation of the ultrasonic flowmeter on the large diameter (especially the large diameter of 1 m or more) has obvious advantages, and the construction is not difficult, the cost is relatively low, and the maintenance is convenient.

The external clip-type ultrasonic flowmeter (Ultrasonic flow measurement) is easy to carry and install.

Extended reading: 2 inch Water Flow Meter

Open channel flowmeter

Most of the sewage treatment plant sewage discharge methods are natural flow, that is, the flow of sewage in the pipeline or in the pipeline is not full.

A waterway that flows in such a non-full-tube state, that is, a waterway with a free surface, is called an “open channel.”

Even in the so-called “dark channel” waterway, since the liquid flows naturally, it also belongs to the open channel.

For such waterways, conventional pressurized full flow meters cannot be used when measuring flow.

The measured sewage contains various impurities and other organic chemical components.

Although it has been purified before the sewage is discharged, if a flow meter is used in direct contact with the sewage medium, scaling will inevitably occur inside the flowmeter after a long time.

Or the situation of being corroded, thus affecting the smooth progress of the measurement work.

The advantage of the open channel flowmeter is that the measuring range is large, and the flow measurement is not affected by the return of the tributary surface, the sediment in the water, the bubbles, and the water level. And the flow sensor will have resistance to the water flow, the structure is simple, the volume is small. And the installation is Convenience.

It is used in the Pearl River Delta area. The standard channels do not need to be modified, they can be installed directly, and the installation and construction costs are low. Therefore, it is suitable for measuring the discharge of sewage from sewage treatment plants.

Extended reading:
What is the K-factor in a flow meter?
Cryogenic Flow Meters|Liquid Nitrogen-Liquid Oxygen-LNG fluids

Orifice flowmeter

The throttling flowmeter is a metering device, for metering flow that has been used in many previous years. It has the longest history and the most usage.

Nowadays, the common type is the circular orifice type and the tapered inlet plate type.

The working principle is to participate in the one-plate saving part in the fluid pipeline, and the pressure difference transmitter is introduced through the pressure guiding tube to measure the pressure difference between the upstream and the downstream of the saving piece.

According to the measured pressure difference, the instantaneous value of the flow is obtained by accounting.

Because of the inactivity of the water in the pressure guiding tube, in the colder area, the orifice tube of the outdoor equipment in winter is simply frozen (frozen), so that the differential pressure instrument cannot work normally.

When measuring dirty sewage, the orifice plate needs to be cleaned frequently.

If the cleaning is not timely, the measurement accuracy is reduced, and the pressure tube is often blocked by dirt, and the appearance cannot be used.

When the flow rate is measured by the orifice plate method, there are disadvantages such as large pressure loss and large protection amount.

Therefore, by changing the pressure-receiving method, for example, by using the radial pressure method, the influence of the fouling of the orifice plate can be reduced.

Widely used in environmental protection, metallurgy, chemical, pharmaceutical, water supply, food, paper, and other industries.

Read more about Sanitary Flow Meters-316SS, Tri clamp-Pulse- for Brewery

Sewage Flow Meter Selection

Before you make the selection of sewage flow metering instruments.

According to the actual situation of the site and the comparison of different flowmeters:

  1. Electromagnetic flowmeter measurement stability, a wide range of applications, can measure a variety of media, but is susceptible to electromagnetic interference. As the diameter of the pipe increases, its price will become more and more expensive.
  2. Ultrasonic flowmeter has low cost, high measurement accuracy, stable operation, convenient installation and maintenance, and the price will not become higher and higher with the increase of pipe diameter, but it will become more and more expensive due to the increase of sound path.
  3. The open channel flowmeter has a wide measuring range, and the flow measurement is not affected by the change of the medium, but it is limited by the size of the measuring tank.

Read more about: Shop 101: Key Factors In Selecting A Pipe Flow Meter

Generally speaking, in the case of meeting the open channel installation conditions, the flow data is large, and the sewage flow can be transported through the open channel.

And the sputum flowmeter and the trough flowmeter are used for related operations.

In the actual measurement process, such equipment can meet the accuracy requirements of metering and save energy.

It uses a self-flowing method to transport sewage.

Extended reading: Industrial VS Residential inline water flow meters

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Ultrasonic Flow Meter

Clamp on type Ultrasonic Flow Meter is the easiest to install. Convenient measurement. Handheld type optional.



Ultrasonic open channel flowmeters are used to measure flow in the sewer. In the case of a very small water flow, it can be matched with a triangular weir. Its basic structure is to install a weir groove at the outlet of the pipeline, which can be fixed with expansion screws. Finally, use structural glue to plug the surrounding gaps. Ensure that water does not seep from the place where the weir trough and the outlet pipe are connected.

As for how to install the ultrasonic open channel meteor on the weir trough, it is the same as usual. It’s just that the sewer may require battery power. It also needs to be equipped with a wireless RTU. This is also a way to measure the flow in a water channel when the water flow is very small.

Extended reading: Sludge flow meter for sewage treatment return activated sludge system

For the selection of sewage flow meters, various flow meters have their own advantages and disadvantages. In the process of sewage treatment, selection should be made according to actual needs.

The electromagnetic flowmeter is stable in measurement, has a wide range of applications, and can measure a variety of media. But it is easily interfered by electromagnetic waves. As the pipe diameter increases, its price will become more and more expensive.

Ultrasonic flow meters have relatively low cost and high measurement accuracy. run smoothly. Installation and maintenance are convenient, and the price will not increase with the increase of pipe diameter. But it will become more and more expensive because of the increase in sound channels.

The open channel flowmeter has a wide measurement range, and the flow measurement is not affected by changes in the medium. , But it is restricted by the size of the measuring tank. Generally speaking, when the installation conditions of open channels are met, the traffic data is large. Sewage flow operations can be transported through open channels. Weir flow meters and trough flow meters are used for related operations.

Extended reading: sludge level measurement

Flow Metering Principals

  • Differential Pressure Flowmeters
  • Velocity Flowmeters
  • Positive Displacement Flowmeters
  • Mass Flowmeters
  • For Open Channel Flowmeters – weirs, flumes, submerged orifices, current meters, acoustic flow meters and more

For different working principle, We offer different types of flow meters, like:

  • Differential Pressure Flow Meters
  • Orifice Plate
  • Venturi Tube
  • Flow Nozzles
  • The Sonic Nozzle – Critical (Choked) Flow Nozzle
  • Calorimetric Flowmeter
  • Ultrasonic Doppler Flowmeter
  • Positive Displacement Flowmeter
  • Variable Area Flowmeter or Rotameter
  • Velocity Flowmeters
  • Pitot Tubes
  • Electromagnetic Flowmeter
  • Turbine Flowmeter
  • Vortex Flow Meter
  • Thermal Flowmeter
  • Coriolis Flowmeter
  • Mass Flowmeters
  • Open Channel Flowmeters

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Sino-Inst offers sewage flow meter products. About 85% of these are Magnetic flow meters, 3% are Ultrasonic water meters. A wide variety of sewage flow meter options are available to you, such as free samples, paid samples.

The top-selling countries or regions are China, India, and Israel, which supply 99%, 1%, and 1% of sewage flow meter respectively. Sewage flow meter products are most popular in Domestic Market, Mid East, and North America. You can ensure product safety by selecting from certified suppliers, with ISO9001, and Other certifications.

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