The electromagnetic flowmeter has a large measuring range, usually 20:1~50:1, and the optional flow range is wide; the diameter of the electromagnetic flowmeter is wider than other types of flowmeters, from a few millimeters to 3 meters; the positive and negative two-way flow can be measured. The pulsating flow rate can also be measured as long as the pulsation frequency is much lower than the excitation frequency; the meter output is linear in nature; it is easy to select the material type of the fluid contact member, and can be applied to corrosive fluids and the like. Since the electromagnetic flowmeter measures much more with suspended solids or dirt than other flow meters, the probability of failure of the inner wall adhesion layer is relatively high. If the electrical conductivity of the adhesion layer is close to the liquid conductivity, the instrument can output the signal normally, but only change the flow area to form a hidden fault of the measurement error; if it is a high conductivity adhesion layer, the electromotive force between the electrodes will be short-circuited; if it is an insulating adhesion layer The surface of the electrode is insulated to disconnect the measuring circuit. The latter two phenomena will make the meter inoperable.
Executive Standard: JB/T 9248-1999
Nominal diameter: 15, 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2600, 2800, 3000
Maximum flow rate: 15m/s
Accuracy: DNl5~DN600, indication: ±0.3% (flow rate ≥1m/s); ±3mm/s (flow rate <1m/s)
DN700-DN3000, ±0.5% of the indicated value (flow rate ≥0.8m/S); ±4mm/s (flow rate <0.8m/S)
Fluid conductivity ≥5uS/cm
Nominal pressure:
DNl5～DN: 1504.0MPa, DNl5～DN600: 1.6MPa, DN200～DN1000: 1.0MPa, DN700～DN3000: 0.6MPa, Special order: 6.3, 10MPa
Ambient temperature
Sensor: -25 °C - ten 60 °C
Converter and integrated type: -10 ° C - ten 60 °C
Lining material: PTFE, neoprene, polyurethane, polytetrafluoroethylene (F46), screened PFA
Maximum fluid temperature
- Body type 70 °C
Separate type: Polychloroprene lining 80 ° C; 120 °C (specify when ordering)
Polyurethane lining 80 °C
PTFE lining
Polytetrafluoroethylene propylene (F46) 100 °C; 150 °C (specify when ordering)
Screening PFA
Signal electrode and grounding electrode material: stainless steel 0Crl8Nil2M02Ti, Hastelloy C, Hastelloy B, titanium, tantalum, platinum/rhodium alloy, stainless steel coated tungsten carbide
Electrode scraper mechanism: DN300-DN3000
Connecting flange material: carbon steel
Grounding flange material: stainless steel 1Crl8Ni9Ti
Import protection:
DN65—DNl50: Stainless steel 1Crl8Ni9Ti
Flange material
DN200～DNl600: Carbon steel ten stainless steel 1Crl8Ni9Ti
Shell protection
DNl5～DN3000 separate rubber or polyurethane lining sensor: IP65 or IP68
Other sensors, body flow meters and split converters: IP65
Spacing (separate type): The converter distance sensor generally does not exceed 100m
Selection of measurement types for special industrial and commercial users
2. Case 2: A heavy machine tool factory
The main gas plant of the heavy-duty machine tool factory is 13 production kiln, and there is also a machine repair workshop and 63 mobile burners. The total gas load of all gas facilities is 1837m3/h. See Table 1 for details. The customer promised that all gas facilities could not be fully activated at the same time, the maximum gas consumption required was 1200m3/h, and the minimum pressure required before the furnace was 0.055MPa. The pressure regulator used in the on-site pressure regulating metering box is opened and ready, and the flow meter is in the form of a G1600 turbine table plus bypass.
When debugging the kiln, it was found that the flowmeter in the pressure regulating metering box had a stop-and-go phenomenon. If only some of the kiln was opened or only some of the kiln was used, there would be a phenomenon that the flowmeter did not measure or the measurement error was large.