The mediums that need to be measured in the site are different. Now, a brief introduction is made on the selection of flow meters for different media.
The selection of large water flow meter: suitable for electromagnetic flowmeter, ultrasonic flowmeter. Other applications such as vortex flowmeters, orifice flowmeters, etc. have faded out of this application, and these two types of flow meters are the most important in the industry. In particular, it should be mentioned that the application of Kaifeng Shengda's plug-in flowmeter and electromagnetic flowmeter are better.
Sewage, pulp and other turbid liquid meter selection: electromagnetic flowmeter can be used. However, when choosing an electromagnetic flowmeter, consider that the liquid does not contain more air or bubbles.
The meter with more bubbles of liquid selection: Doppler ultrasonic flowmeter can be selected, using this type of flowmeter to measure the fluid with bubbles, the effect is very good.
Flow meter selection with low conductivity such as pure water and demineralized water: Turbine flow meter is very suitable for measuring such fluids.
Flow meter selection for strong corrosive media such as acid and lye: 1. Electromagnetic flowmeter with acid and alkali lining. 2. clamp type ultrasonic flowmeter.
Selection of flowmeters for mediums with large concentration and large solid particle content such as mortar and electric powder slurry: electromagnetic flowmeter.
Flow meter selection for oil media such as oil and diesel: turbine flow meter and ultrasonic flow meter.
Gas flow meter selection: vortex flowmeter.
General principles for electromagnetic flowmeter selection
(1) Whether the medium to be tested is a conductive liquid or slurry, thereby determining whether an electromagnetic flow meter is selected;
(2) The conductivity of the measured medium determines the type of electromagnetic flowmeter—whether it is high conductivity or low conductivity;
(3) The nominal diameter of the large, small and common flow process pipelines required by the process, determine whether the flow rate of the medium is at a more economical flow point, whether the pipeline needs to be reduced, and then determine the diameter of the flowmeter;
(4) Determine whether to use an integrated or split flowmeter, and the degree of protection of the flowmeter, etc., based on the layout of the process piping.
(5) Selecting the electrode type according to whether the measured medium is easy to crystallize or crusting;
(6) selecting an electrode material according to the corrosiveness of the measured medium;
(7) The corrosiveness, wear and temperature of the measured medium determine the lining material to be used;
(8) The high working pressure of the measured medium determines the nominal pressure of the flow meter;
(9) The insulation of the process piping determines the type of grounding ring.
Application of electromagnetic flowmeter
Because electromagnetic flowmeter has its unique advantages, it is widely used in chemical, chemical fiber, food, paper, sugar, water supply and drainage, environmental protection, water conservancy, steel, petroleum, pharmaceutical and other industrial fields. Various acid and alkali salt solutions, mud, pulp, pulp, coal water slurry, corn syrup, fiber pulp, lime slurry, water supply and drainage, brine, hydrogen peroxide, beer, wort, various beverages, black liquor, green liquor, etc. The volumetric flow of the medium.
The main technical parameters
Nominal diameter series DN (mm)
Pipeline PTFE lining:
Pipeline rubber lining:
Special specifications can be customized
Flow direction: current output
Positive, negative, net flow
Range ratio: 150:1
Repeatability error: ±0.1 of the measured value
Accuracy level: pipeline type: 0.5 level, 1.0 level
Measured medium temperature
Ordinary rubber lining: -20 ~ +60 ° C
High temperature rubber lining: -20 ~ +90 ° C
PTFE lining: -30 ~ +100 ° C
High temperature PTFE lining: -30 ~ +180 ° C
Rated operating voltage
Pipe type: DN6-DN100≤1.6Mpa, DN125-DN225≤1.0Mpa high pressure can be customized
Conductivity of the measured fluid ≥ 5us / cm (integrated)
Most water-based media have a conductivity of 200-800 us/cm, and electromagnetic flow meters can be used to measure the flow rate.
Load resistance: 0 ~ 10mA, 0 ~ 1.5kΩ
4 to 20 mA, 0 to 750 Ω
Digital frequency output
The upper limit of the output frequency can be set to open the bidirectional output of the open collector of the transistor with optical isolation from 1 to 5000HZ. External ≤35V, the maximum current of the collector is 25mA when conducting
Straight pipe length
Pipeline type: upstream ≥5DN, downstream ≥2DN
The flowmeter and the pipe are flanged, and the flange connection size should meet the requirements of GB11988.
Explosion-proof mark: mdllBT4
Ambient temperature: -10 ° C ~ +55 ° C
Relative temperature: 5% to 90%
Total power consumption: less than 15W