Measurement of slurry flow meter

Measurement of slurry flow meterAnti interference technology

1Monitoring technology for power supply voltage of microprocessor system

When the power supply transient undervoltage and excitation switch pulse action occur in the microprocessor system of electromagnetic flowmeter, it can cause microprocessor misoperation, data loss and other phenomena. Therefore, reliable reset circuit and power supply voltage monitoring technology must be adopted. A simple and practical method is to use a low-cost power supply combined with a high-sensitivity power supply voltage monitor to improve the microprocessor system and anti-interference ability.

2Frequency compensation technology for synchronous sampling

Synchronous sampling and power frequency monitoring compensation technology are effective methods to improve the ability to resist power frequency interference caused by the mixing of power frequency interference and power frequency fluctuations in the flow signal potential. Synchronous sampling technology, whose sampling pulse width is an integer multiple of the power frequency period, makes the average value of power frequency interference in the flow signal potential equal to zero, in order to eliminate the influence of power frequency interference; The frequency fluctuation compensation of power supply is to ensure that the excitation power supply and sampling pulse can be synchronously adjusted in the dynamic fluctuation of frequency, truly realizing synchronous sampling technology and synchronous excitation technologyA/DConversion to reduce the impact of power frequency interference.

3The design of preamplifier is a crucial step in improving anti-interference capability

The output flow signal of the sensor is very weak, with a high internal impedance, resulting in high input/output impedance, low drift, low noise, and highCRMMA preamplifier is necessary to meet the requirements of resisting in-phase and common mode interference. The preamplifier adoptsJFETA high input impedance voltage buffer, low drift and low noise reducer, and precision resistors are carefully matched to form an instrument amplifier. Input protection technology, common mode voltage bootstrap technology, and grounding technology are used to greatly improve the ability to resist common mode interference and suppress the influence of zero drift.

4：Measurement of slurry flow meterAdopting*HCMOSSeries chip technology

adopt74HCSeries chip technology is more commonly used74LSThe low noise tolerance of the series of chips has been improved2.4Doubling, increased tolerance for high noise levels2.1Multiple, the entire hardware of the intelligent electromagnetic flowmeter adopts74HCThe series of chips not only reduces the overall power consumption, but also improves the anti-interference ability of the components themselves, laying the foundation for the small and lightweight integration of power flow meters.

5Excitation technology is an important means to improve the anti-interference ability of intelligent electromagnetic flow meters

The development of excitation technology not only reduces the effects of electrode polarization potential, mud interference, and flow noise, but also changes the form of power frequency interference, making it easier for synchronous sampling technology to handle power frequency interference noise and avoid its impact. At present, electromagnetic flow sensors use frequency synchronous three value low-frequency rectangular excitation and dual frequency rectangular wave excitation to improve the overall anti-interference ability, measurement accuracy, and reliability.

Product characteristics of pipeline slurry flowmeter

1There are no movable parts or flow blocking components in the pipeline, and there is almost no additional pressure loss during measurement.

2The measurement results are related to physical parameters such as flow velocity distribution, fluid pressure, temperature, density, viscosity, etc.

3On site, the range can be modified online according to the actual needs of the user.

4High definition backlightLCDDisplay, fully Chinese menu operation, easy to use, simple to operate, easy to learn and understand.

5AdoptingSMDDevices and surface mount（SMT）Technology and circuit reliability are high.

6Adopting16The embedded microprocessor has fast processing speed, high accuracy, programmable low-frequency rectangular wave excitation, improved stability of flow measurement, and low power consumption.

7Fully digital processing, strong anti-interference ability, reliable measurement, high accuracy, and a flow measurement range of up to150：1LowEMISwitching power supply, suitable for a wide range of power supply voltage changes, resistant toEMIGood performance.

8There are three integrators inside that can display the forward cumulative amount and the difference cumulative amount respectively. There is also a non power down clock inside that can record16The second power outage time. (Optional)

9HavingRS485TheRS232TheHartandModbusWaiting for digital communication signal output. (Optional)

10It has self checking and self judging functions.

11Infrared handheld operator,115KHZThe communication speed and long-distance non-contact operation converter have functions. (Optional)

12The hourly volume recording function records the flow volume in hours and is suitable for the time-sharing measurement system. (Optional)

Main technical data of pipeline slurry flowmeter

The selection of pipeline slurry flow meters, such as instruments, is a very important task in instrument applications. Relevant data shows that 2/3 of instrument failures in practical applications are caused by instrument errors

Please pay special attention to cases caused by incorrect selection or installation.

Collect data:

1. Composition of the tested fluid

2. * Traffic, * Small Traffic

3. Work pressure

4. * Temperature, * Low Temperature

The tested fluid must have a certain degree of conductivity, with a conductivity>5 μ S/CM

*The traffic and * small traffic must comply with the numbers in the following table:

The actual working pressure must be less than the rated working pressure of the flowmeter.

*The working temperature and low temperature must meet the temperature requirements specified by the flowmeter.

Determine if there is negative pressure present.

You can choose the corresponding flow meter based on the flow rate in the table above. If the inner diameter of the selected flow meter does not match the current inner diameter of the process pipeline, it should be reduced or expanded.

If the pipeline undergoes shrinkage, consideration should be given to whether the pressure loss caused by shrinkage will affect the process flow.

From the perspective of product price, smaller caliber flow meters can be chosen to relatively reduce investment.

When measuring clean water, the economic flow rate is 1.5-3m/s. When measuring solutions that are prone to crystallization, the flow rate should be appropriately increased to 3-4m/s to achieve self-cleaning and prevent adhesion and sedimentation

Cumulative effect; When measuring abrasive fluids such as slurry, the flow rate should be appropriately reduced to 1.0-2m/s to reduce wear on the lining and electrode. Very rarely used in practical applications

7m/s， Exceeding 10m/s is even rarer.