Split Water Electromagnetic Flow Meter For Wastewater

Technical introduction:

The DMF flow sensor is based on Faraday's law of electromagnetic induction. The conductor cutting the magnetic lines is not an ordinary metal, but a liquid fluid or a liquid-solid two-phase fluid with a certain conductivity. When the conductive medium being measured moves along cutting magnetic lines of force in the magnetic field. An induced electromotive force is generated in the conductive medium, and the induced electromotive force is detected by a pair of electrodes. The voltage signal V can be expressed by the following formula: V=KBDV K: Proportional constant B: Magnetic induction intensity D: Measuring tube inner diameter v: The average flow velocity signal v in the measuring section, after being processed by the converter, the auxiliary output is linear with the flow rate The related frequency signal o 5VOCO-5VDC is used for accumulation or control of subsequent instruments. Generally, the flow velocity of the medium measured by the industrial electromagnetic flowmeter is preferably 2 to 4m/s. In special cases, the minimum flow velocity should be no less than 0.1m/s, and the maximum flow velocity should be no more than 8m/s. If the medium contains solid particles, the common flow rate should be less than 3m/s to prevent excessive friction between the lining and the electrode; for viscous fluids, the flow rate can be greater than 2m/s. A larger flow rate will help automatically eliminate the stickiness attached to the electrode. The effect of hysteresis is conducive to improving measurement accuracy. Under the condition that the measuring range Q has been determined, the size of the flow meter diameter D can be determined according to the range of the above flow rate V, and its value is calculated by the following formula:
Q=πD?V/4
Q: Flow rate (㎡/h) D: Pipe inner diameter V: Flow rate (m/h)
The measuring range Q of the electromagnetic flowmeter should be greater than the expected maximum flow value, and the normal flow value should be slightly greater than 50% of the full-scale scale of the flowmeter.

Rate-Of-Chng and Limit Time
‘Rate-of-change’ limit technique is used to eliminate application-related high electrical noise contained in the process flow signal.
To check electrical noise, two parameters are defined: ‘Rate-of-change’ limit and ‘Control limit time’. If the sampled flow value exceeds the set rate-of-change limit value based on the averaged flow rate value up until the sampled time, the system will reject that sampled value and instead the averaged value including the rate-of-change limit value in place of the rejected sampled value will be output. However, if the limit-exceeding sampled value continues for the same flow direction for more than the preset control limit time, that data will be used as output signal. Fig 6 illustrates the effect of noise-suppressing by rate-of-change limit.
The value of rate-of-change limit can be set from 0 to 30% of flow range and limit time ranges from 0 to 20 seconds. If either of the two parameters is set to nil, the function is disabled.
The rate-of-change limit function is not suitable for short period measurement and flow meter calibration.

Features
1. Measurement is not affected by the variation of flow density, viscosity, temperature, pressure and conductivity. High accuracy measurement is guaranteed according to the linear measurement principle.
2. No obstacle in the pipe, no pressure-loss and lower requirement for straight pipeline.
3. DN 6 to DN2000 covers a wide range of pipe size. A variety of liners and electrodes are available to satisfy different flow characteristic.
4. Programmable low frequency square wave field excitation, improving measurement stability and reducing power consumption.
5. Implementing 16 bits MCU, providing high integration and accuracy; Full-digital processing, high noise resistance and reliable measurement; Flow measurement range up to 1500:1.
6. High definition LCD display with backlight.
7. RS485 or RS232 interface supports digital communication.
8. Intelligent empty pipe detection and electrodes resistance measurement diagnosing empty pipe and electrodes contamination accurately.
9. SMD component and surface mount technology (SMT) are implemented to improve the reliability.

Main Applications

TQMF electromagnetic flowmeter can be used to measure the volume flow of conductive fluid in a closed pipeline. It is widely applied in the flow measurement and control in the fields of chemical and petroleum industry, metallurgy industry, water and waste water, agriculture and irrigation, paper making, food and beverage industry and pharmaceutical industry. 1.3Ambient Conditions Ambient temperature: sensor: -25℃ to + 60℃; converter: -25℃ to + 60℃. Relative humidity: 5% to 90%; 1.4Working Conditions Maximum fluid temperature: Compact type: 60℃ Remote type: Teflon 150℃ Neoprene 80℃; 120℃ Polyurethane 70℃ Fluid conductivity: ≥ 5S/cm

Measuring Principles

The measuring principle of electromagnetic flowmeter is based on the electromagnetic induction law of Farady. The sensor is mainly composed of measuring tube with isolate lining, a pair of electrodes installed by penetration of the measuring tube wall, a pair of coils and iron core to produce working magnetic field. When the conductive fluid flows through the measuring tube of the sensor, the voltage signal in direct proportion to the average flow velocity of the fluid will be inducted on the electrodes. The signal is amplified and treated by the transmitter to realize various display functions.

Converter Circuit Schematic

The converters supplies a stable exciting current to the coil in the sensor of electronetic flowmeters to get B constant and amplifies the electromotive force and convert it into standard signals of current or frequency so that the signals can be used for displaying, controlling and processing. The schematic of converter circuit is shown in Fig. 2.1.

Table of Parameter Setting Menu

The converter setting menu consists of 45 items. Many of them are set up by manufacturer before shipping. It is not necessary to change them when applying. There are only a few of them to be set by user according to the application. The menu items are listed in the table below:

Scenario application:

FAQ
1. Q: What information need to be provided to choose the suitable model?
A: Application field, Nominal pressure ,Medium & medium temperture , Power supply , Output,
Flow range, Accuracy, Connection and other parameters.
2. Q: Are you a trade company or a manufacturer?
A: We are an ISO approved manufacturer specialized in level and flow measuring instruments.
OEM & ODM service are available. Welcome to visit us in China.
3. Q: What is your MOQ?
A: To start our cooperation, sample order is acceptable.
4. Q: What is your delivery date for the Intelligent Mini Micro Turbine Fuel Oil Diesel Flow Meter?
A: The delivery date is about 3-15 working days after receipt of payment.
5. Q: What is your payment terms?
A: We support T/T, PayPal ,Western Union.
For mass production order, it is 30% deposit in advance and 70% balance before shipment.
6. Q: Do you have a warranty for the Flow Meter?
A: Yes, we have the warranty of 12 months.

Suzhou Beite Smart Instrument Co., Ltd. was established in 2007.It is an automated instrument manufacturer integrating R&D, design, manufacturing, sales and system complete services.

After years of development, the company's new factory covers an area of ​​15 acres, with a workshop area of ​​4000m2. It has complete production and processing equipment. The electronics workshop has a modern SMT assembly line and a complete electronic design laboratory. The machinery workshop has multiple precision CNC lathes, ordinary lathes, CNC milling machines, fully automatic circumferential seam welding machines, drilling machines and other equipment. The calibration workshop has two liquid calibration test lines and one small and medium flow gas calibration test line. Each product has been actually calibrated and verified to ensure product quality.

The company has strict quality control in every aspect from product design, raw material procurement and processing, manufacturing and assembly, testing and inspection to product delivery, striving for zero defect products, and using scientific management, strict technology, sophisticated equipment, to ensure product quality. quality. The company's products, from hardware to software, all have the company's independent intellectual property rights.

The company's products are widely used in municipal administration, petroleum, chemical industry, metallurgy, pharmaceuticals, thermoelectric papermaking, food environmental protection and scientific research fields, and are exported to Southeast Asia, South America, Europe and other countries. Beite's integrity, strength and product quality have been recognized by the industry.

The company's main products include metal tube float (rotor) flowmeters, glass rotor flowmeters, plastic tube flowmeters, turbine flowmeters, thermal gas mass flowmeters, gas turbine flowmeters, intelligent electromagnetic flowmeters, vortex flowmeters, pipeline ultrasonic flowmeters, magnetic flap level meters, ultrasonic level meters, intelligent radar level meters, pressure transmitters, flow totalizers, batch control systems, etc. There are more than a dozen series and hundreds of varieties.