ZRN-LDC series electromagnetic flowmeter

It is a fully intelligent electromagnetic flowmeter developed by our company Beijing Zhongrui Energy Instrument Technology Co., Ltd. using advanced domestic and foreign technologies. Its all Chinese electromagnetic converter core adopts a high-speed central processing unit, with fast calculation speed, high accuracy, and reliable performance. The converter circuit design adopts international advanced technology, with an input impedance of up to 1015 ohms and a common mode rejection ratio better than 100db, which can measure fluid medium flow rates with lower conductivity. The sensor adopts a magnetic circuit structure with non-uniform magnetic field technology, which ensures stable and reliable magnetic field. Our company's consistent goal is to ensure that customers can buy with confidence, use with ease, and receive satisfactory service.

The measurement principle is Faraday's law of electromagnetic induction,

The main components of the sensor are: measuring tube, electrode

Calibration device for company electromagnetic flowmeter

Flow meter assembly diagram

Excitation coil, iron core, and magnetic yoke housing. It is mainly used to measure the volumetric flow rate of conductive liquids and slurries in closed pipelines. Including highly corrosive liquids such as acids, alkalis, salts, etc. This product is widely used in industries such as petroleum, chemical, metallurgical, textile, food, pharmaceutical, papermaking, as well as in fields such as environmental protection, municipal management, and water conservancy construction.

The measurement of flow rate is not affected by changes in fluid density, viscosity, temperature, pressure, and conductivity. The sensor induced voltage signal is linearly related to the average flow rate, resulting in high measurement accuracy.

★ There is no obstruction in the measuring pipeline, so there is no additional pressure loss; There are no movable parts inside the measuring pipeline, so the sensor has an extremely long lifespan.

Due to the fact that the induced voltage signal is formed in the entire space filled with a magnetic field and is the average value on the surface of the pipeline, the sensor requires a shorter straight pipe section, with a length of 5 times the diameter of the pipeline.

The sensor part only has the inner lining and electrodes in contact with the measured liquid. As long as the electrode and inner lining materials are selected reasonably, they can be corrosion-resistant and wear-resistant.

The IC-LDC converter adopts internationally advanced microcontroller (MCU) and surface mount technology (SMT), with reliable performance, high accuracy, low power consumption, stable zero point, and convenient parameter setting. Click on the Chinese display LCD to show accumulated flow, instantaneous flow, flow rate, flow percentage, etc. TU-DC electromagnetic flowmeter is suitable for measuring the volumetric flow rate of conductive liquids and slurries in closed pipelines, such as clean water, sewage, various acid-base salt solutions, mud, slurry, pulp, and liquids related to food.

★ Bidirectional measurement system, capable of measuring forward and reverse flow rates. Using special production processes and high-quality materials to ensure stable product performance over a long period of time.

Technical parameters of electromagnetic flowmeter:

Selection of electromagnetic flowmeter

The selection of instruments is a very important task in instrument applications. Relevant data shows that 2/3 of instrument failures in practical applications are caused by incorrect selection or installation of instruments. Please pay special attention.

The correct selection of electromagnetic flowmeter is a prerequisite for ensuring the good use of electromagnetic flowmeter. The selection of the type of electromagnetic flowmeter should be based on the physical and chemical properties of the measured fluid medium, so that the diameter, flow range, lining material, electrode material, and output current of the electromagnetic flowmeter can adapt to the properties and flow requirements of the measured fluid. Measurable fluids: According to the working principle of electromagnetic flow meters, fluids that can be measured with electromagnetic flow meters must be conductive. Strictly speaking, except for high-temperature fluids, any fluid with a conductivity greater than 5 μ/cm should be measured with the corresponding electromagnetic flow meter. Therefore, non-conductive gases, vapors, oils, acetone, and other substances cannot be measured with electromagnetic flow meters. Determination of sensor diameter: The flow rate of the flowmeter is best within the range of 0.3-15m/s, and the diameter of the flowmeter can be selected to be consistent with the diameter of the user's pipeline. When the flow rate is lower than 0.3m/s, it is best to locally increase the flow rate at the instrument location and use a reduction method: when the central cone angle of the reducer is not greater than 15oC, the reducer can be considered as part of the straight pipe section. Selection of integrated or separated type: Integrated type: In better on-site environments, integrated type is generally chosen, that is, the sensor and converter are assembled into one unit.

Separated type: The sensor and converter are installed separately in different locations, and the separated type is generally selected when the following situations occur. When ordering, the separation distance of the sensor converter should be specified, generally not exceeding 100m, and the converter should be wall mounted.

★ Collect data

① Composition of the tested fluid ② Maximum flow rate, minimum flow rate ③ Maximum working pressure ④ Maximum temperature, minimum temperature

The range Q of the electromagnetic flowmeter should be greater than the expected maximum flow value, while the normal flow value should be slightly greater than 50% of the flowmeter's full-scale scale.

Instrument selection

◆ Range confirmation

The flow rate of the medium measured by the general industrial electromagnetic flowmeter should be 2-4m/s. In special circumstances, the minimum flow rate should not be less than 0.2m/s and the maximum should not be greater than 8m/s.

If the medium contains solid particles, the commonly used flow rate should be less than 3m/s to prevent excessive friction between the lining and the electrode; For viscous fluids, the flow velocity can be chosen to be greater than 2m/s,

A higher flow velocity helps to automatically eliminate the effect of viscous substances attached to the electrode, which is beneficial for improving measurement accuracy.

Under the condition that the range Q has been determined, the size of the flowmeter diameter D can be determined based on the range of flow velocity V mentioned above, and its value can be calculated by the following formula:

Q=π D2V/4

Q: Flow rate (㎡/h) D: Inner diameter of pipeline V: Flow rate (m/h)

The range Q of the electromagnetic flowmeter should be greater than the expected maximum flow value, while the normal flow value should be slightly greater than 50% of the flowmeter's full range scale for installation site selection

In order to ensure the stable and reliable operation of the electromagnetic flowmeter, the following requirements should be noted when selecting the installation location:

1. Try to avoid ferromagnetic objects and equipment with strong electromagnetic fields (such as large motors, transformers, etc.) to prevent the magnetic field from affecting the working magnetic field and flow signal of the sensor.

2. It should be installed in a dry and ventilated place as much as possible, avoiding direct sunlight and rain. The ambient temperature should be between -20 and+60 ℃, and the relative humidity should be less than 85%.

3. There should be ample space around the flowmeter for easy installation and maintenance.

The measurement principle of electromagnetic flowmeter does not depend on the characteristics of flow rate. If there is a certain amount of turbulence and vortex generated in the non measurement area of the pipeline (such as bends, tangential flow restrictions, or partially open shut-off valves upstream), it is irrelevant to the measurement. If there is a steady-state eddy current in the measurement area, it will affect the stability and accuracy of the measurement. In this case, some measures should be taken to stabilize the flow velocity distribution:

a. Increase the length of the front and rear straight pipe sections;

b. Adopting a traffic stabilizer;

c. Reduce the cross-section of measurement points.

Selection of electrode materials for electromagnetic flowmeter:

Lining material selection:

The lining material should be selected based on the corrosiveness, wear resistance, and temperature of the tested medium.

Selection of protection level:

1. IP65: Anti spray type, allowing the faucet to spray water on the sensor from any direction, with a spray pressure of 30kPa, a water output of 12.5L/s, and a distance of 3m.

2. IP68: Submersible type, capable of long-term operation in water.

The protection level should be selected according to the actual situation. For sensors installed below the ground, if they are frequently flooded, IP68 should be selected. For sensors installed above the ground, IP65 should be selected.

Selection of Additional Features

The basic model of LDE intelligent electromagnetic flowmeter comes with display, output 4-20mA and 0-1kHz alarm functions, and other additional functions can be added according to the actual situation.

3. Split installation: If the sensor needs to be installed below the ground or for other reasons, a split installation method should be selected.

4. RD-485 communication: If a converter is required to communicate with other devices, RS-485 communication function should be selected.

Table 1 Correspondence between Flow Range and Caliber