Accurate detection of sewage flow plays a critical role in industrial production processes. Through precise monitoring of sewage flow, relevant departments can effectively evaluate pollution discharge conditions. When measuring sewage flow, electromagnetic flow meters are the preferred choice for sewage flow measurement. The velocity-area method is a specialized solution for partially filled pipe sewage flow measurement.
This article will detail issues related to sewage flow monitoring.
What is a Sewage Flow Meter?
A sewage flow meter is a device used to measure sewage flow. Generally, electromagnetic flow meters are the most commonly used sewage flow meters.
Electromagnetic flow meters can be used for both full-pipe and partially filled pipe sewage measurement. Sewage flow meters can be widely used for flow monitoring in municipal water supply, steel, petroleum, chemical, power, industrial, water conservancy, water administration, and water resources. They are particularly suitable for flow measurement in channels, small rivers, and wastewater metering in environmental protection applications.
Wastewater VS Sewage
Wastewater refers to the collective term for water discharged from residential activities and stormwater runoff. It includes domestic sewage, industrial wastewater, and other non-reusable water. such as initial rainfall runoff entering drainage pipes. Generally, it denotes water that cannot be recycled. After primary pollution, it cannot meet specific standards through purification treatment.
Sewage refers to contaminated discharge water from domestic and industrial sources. Water that has lost its original functional use is termed sewage. Primarily consisting of post-domestic use water, it contains higher organic matter. And it is relatively easier to treat.
In industrial processing, sewage and wastewater have the following challenges that complicate flow measurement:
- Large discharge volumes, extensive pollution coverage, and diverse discharge methods;
- Wide variety of pollutants with significant concentration fluctuations;
- Corrosive and toxic. Sewage contains highly acidic or highly alkaline pollutants. It is harmful to water quality;
- Highly variable migration patterns and transformation characteristics after pollutant discharge;
- Difficulties in restoring water quality.
What are the Best Flow Meters for Sewage Processing?
Electromagnetic flow meters are most suitable for measuring sewage flow. Conductivity is a prerequisite for electromagnetic flow meters to function properly. Sewage contains a large amount of impurities and salts, giving it a certain level of conductivity. Therefore, electromagnetic flow meters can be used for sewage measurement.
Electromagnetic Flow Meters Advantages:
- High accuracy;
- Stable measurement;
- Broad applicability;
- Customization available;
- Users can select electrodes and linings based on the medium.
- Measurements in harsh conditions
Electromagnetic flow meters can be categorized based on pipeline flow conditions into full-bore and partially full pipe:
Full-bore electromagnetic flow meters are further divided into integrated-type, split-type, high-pressure, and insertion-type.
Integrated Electromagnetic Flow Meters:
Integrated electromagnetic flow meters combine the sensor and converter into a single unit. Its integrated structure makes pipeline installation more convenient. The integrated structure makes pipeline installation more convenient. Due to its compact design, it is ideal for space-constrained applications and scenarios requiring extensive data exchange. Integrated electromagnetic flow meters often support protocols such as Modbus and HART. They enable complex data exchange with remote systems and equipment such as energy consumption monitoring systems and management systems.
Split Electromagnetic Flow Meters:
Split electromagnetic flow meters are composed of a sensor (responsible for measurement) and a converter (handling signal processing and display). This design can be arranged and combined in accordance with specific requirements. This design allows the sensor to be installed within the flow pipeline, while the converter can be installed at the measurement point. It is suitable for applications with harsh field measurement environments or where remote display is required. Split electromagnetic flow meters communicate with external devices via various transmission methods such as 4-20mA analog signals or RS-485 communication. They can manage remote data transmission.
High-Pressure Electromagnetic Flow Meter:
Comprising a high-pressure electromagnetic flow meter and intelligent converter, it is specifically designed for measuring the volumetric flow of conductive liquids or liquid-solid mixtures. such as drilling mud, cement slurry, and high-pressure water injection. Under high-pressure conditions in geological exploration, petroleum exploration, and oilfield systems.
Insertion Electromagnetic Flowmeter:
Typically installed externally on pipelines, the insertion electromagnetic flow meter employs insertable electrodes to measure flow. They measure flow through inserted electrodes, making them suitable for media that are difficult to measure directly. such as viscous, corrosive liquids, liquids containing residual gases or solid impurities, and liquids with high viscosity. They can be installed either laterally or vertically.
Partially full pipe Electromagnetic Flow meters consist of an electromagnetic flow velocity sensor, an ultrasonic level sensor, and a flow display unit. It continuously measures the flow velocity and liquid level of fluids in a pipeline. Users only need to input the inner diameter of a circular pipe or the width of a square pipe. Partially full pipe Electromagnetic Flowmeters will automatically calculate the flow rate within the pipe and display measurement parameters. such as instantaneous flow rate, flow velocity, and cumulative flow.
All of the above electromagnetic flowmeters can be used to measure sewage flow. You need to select the appropriate flowmeter based on your actual operating conditions.
Sino-Inst Featured Sewage Flow Meter
Why Sewage Flow Monitoring Matters?
Based on our many years of sewage flow measurement experience, sewage flow monitoring is important in multiple aspects.
Environmental Protection and Water Quality Monitoring:
Real-time monitoring of sewage flow and tracking of wastewater discharge lets staff promptly detect abnormal flow and leaks, thereby preventing water pollution incidents.
Optimizing Sewage Treatment Processes:
Flow monitoring precise data provides real-time inflow and outflow of sewage to treatment plants. Help optimize treatment processes, adjust operational parameters, enhance efficiency, and reduce costs.
Environmental Emergency Alerting:
A sewage flow alert system enables early measurement of anomalies. It facilitates a timely emergency response to maximize protection of the aquatic environment.
Sewage Network Management:
Flow monitoring reveals transmission conditions within urban sewage networks. It enables timely monitoring of blockages, leaks, and other issues for maintenance and repairs to ensure unimpeded sewage flow.
Selecting the Most Suitable Sewage Flow Meter
We have extensive experience in sewage measurement, so we concluded the following considerations should be considered when choosing a sewage flow meter:
- Sewage Properties: Confirm the element, temperature, pressure, and other properties of the sewage to select the appropriate flow meter.
- Flow Range: Select a flow meter with a measurement range that exceeds the actual sewage flow range.
- Pipe Diameter Range: Determine the pipe size for the flow meter in advance when measuring sewage flow to ensure accurate results. The suitable pipe diameter is essential for accurate sewage flow measurement.
- Measurement Precision: Select the appropriate flow meter accuracy based on your actual requirements. Ensure effective sewage treatment.
- Maintenance Costs: Consider maintenance and calibration expenses to select cost-effective products.
- Installation Environment: Installation location and flow velocity all influence selection and require a comprehensive evaluation.
What Does Sewage Flow Mean?
Sewage flow refers to the volume of sewage passing through a defined cross-sectional area per unit time. Common units: m³/s or m³/h. Based on our many years of sewer flow measurement experience, we summarize two calculation methods for your reference:
Water Level-Flow Relationship Method
This method determines wastewater volume by observing a water level-flow relationship curve. It is suitable for rivers or waterways that require long-term monitoring. By monitoring and measuring the current water level and referencing a pre-set flow-level relationship curve, the current flow rate can be estimated.
Velocity-Area Method
It is the easiest method for calculating sewage flow rate. This method requires measuring the sewage flow velocity and the cross-sectional area of the pipe or channel.
By using this formula, we can calculate the sewer flow rate.
Q = A × v,
where v is the flow velocity, Q is the flow rate, and A is the cross-sectional area. Electromagnetic flow meters can measure sewage flow velocity. And calculate the cross-sectional area based on the shape and size of the pipe.
How to Check If a Flow Meter is Functioning Properly?
The following symptoms indicate a malfunctioning flow meter:
- No flow output or abnormal output.
- Reading deviations.
- Alarm or fault indicator lights are activated.
What are the disadvantages of ultrasonic flow meters?
Temperature Limitations: Ultrasonic flow meters have restrictions on the temperature range of the measured fluid.
Poor Interference Resistance: Ultrasonic flow meters are susceptible to interference from bubbles, scaling, pumps, and other sources of ultrasonic noise, which can affect measurement accuracy.
Strict straight pipe section requirements are essential: 20 pipe diameters upstream and 5 pipe diameters downstream. Failure to meet these specifications results in poor dispersion and reduced measurement accuracy.
Complex Measurement Circuitry: Achieving high-precision results demands exceptional accuracy in sound velocity measurement. This increases the complexity and cost of equipment design and implementation while complicating measurement circuitry.
Expensive: Compared to other alternative flow meters, ultrasonic flow meters are more expensive because of the higher initial purchase cost and the higher maintenance requirements.
In short, electromagnetic flow meters play an important role in sewage flow measurement. Sino-Inst has deep expertise in flow measurement, with numerous successful sewage measurement cases. Our sewage flow meters are highly regarded for their quality and have earned praise from various customers. We can provide customized solutions free of charge. Please contact us immediately.
