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The advantages of micro flowmeters in industry
Vapor vortex flowmeter is suitable for the industrial production line of steam material flow measurement of fluid mechanics, steam feature is working pressure damage small vortex flowmeter, category of large measuring range, high precision, when volume flow measurement load work basically not influenced by fluid density, pressure, temperature, viscosity and so on the dangers of main parameters.Unable to move mechanical parts, so high credibility, small amount of maintenance.The main parameters of the instrument can be stable for a long time.The heating furnace vapor flowmeter adopts the piezoelectric in-situ stress controller, which has high dependability and can work within the temperature range of -20¡æ ~ +250¡æ.There are analog standard data signals, but also large digital differential signal output, very easy to use with electronic computers and other large digital system software supporting facilities, is a better, ideal flow meter.
In steam-hydrodynamics, when triangular cylindrical vortex generators are set up, standard vortexes are generated alternately from both sides of the vortex generator. Such vortexes are called Carmen vortexes. As shown in the figure below, the vortexes are arranged in the middle and downstream of the vortex generator in an asymmetric and encrypted manner.
The advantages of micro flowmeters in industry
Assuming that the occurrence frequency of the vortex is f, the mean water flow of the measured material is, the total width of the inflow surface of the vortex generator is d, and the nominal surface diameter is d, the following expressions can be obtained:
F = SrU1 / d = SrU/md
(1) in formula U1-- mean water flow on both sides of the vortex generator, m/s;
Sr-- strouhal number;
M -- the ratio of the total area of the bow on both sides of the vortex generator to the total area of the pipeline section
The volume flow of pipeline contents is qv= D2U/4= D2mdf/4Sr
(2) K = f/qv = PI D2md / 4 sr - 1
(3) in formula K-- meter index of flowmeter, pulse number /m3 (P/m3).
K is related not only to the geometric specifications of vortex generator and pipeline, but also to strouhal number.Strouhal number is a dimensionless main parameter, which is related to the appearance and Reynolds number of the vortex generator. Figure 2 shows the relationship between strouhal number of the cylindrical vortex generator and the Reynolds number of the pipeline.As can be seen from the figure, within the range of ReD=2×104 ~ 7×106, Sr can be regarded as a constant, which is the scope of all normal operation of the instrument.When measuring the vapor flow, the flow measurement formula of VSF is (4).
In the formula, qVn and qV are respectively the volume flow under thermodynamic temperature (0oC or 20oC, 101.325kPa) and load, m3/h;
Pn, P-- absolute pressure at thermodynamic temperature and load respectively, Pa;
Tn, T-- thermal temperature at thermodynamic temperature and thermal temperature at load, K;
Zn, Z-- are vapor compressibility at thermodynamic temperature and load, respectively.
As can be seen from the above equation, the monopulse frequency data signal output by VSF will not be harmed by the hydrodynamic physical properties and component transformation, that is, the meter index is only related to the appearance and specification of the vortex generator and pipeline within a certain Reynolds number range.However, as the flow meter in the balance of raw materials and energy metering needs to monitor the quality flow, at this time the output data of the flow meter should be additional detection of volume flow and fluid density, fluid mechanics and physical properties and components of the flow measurement verification or have immediate harm.
The heating furnace vapor flowmeter is a new type of flowmeter for hydrodynamics flow measurement of closed pipelines based on the basic principle of karman vortex.With its excellent material adaptability, without temperature working pressure compensation can immediately measure the load volume flow of steam, gas, vapor, water, liquid, configured temperature, liquid level sensor can measure the standard state volume flow and quality flow, is the ideal alternative to the throttle flowmeter commodity.
In concrete application, usually a larger flow rate well below the limit on the instrument, and if, with the change of load, the minimum flow rate and is usually less than the limit under the instrument, the instrument is not midway through it a better job at work, in order to deal with this problem, the general selection in reducing improve measurement in measurement of water flow, and using the diameter instrument for measuring instrument, but be sure to be in this kind of method of variable diameter variable diameter pipe between the instrument and a length of 15 d around to take over the period of rectifier, make the production processing, installation is convenient.I look for the enterprise development profile of arc LGZ variable diameter ballast, rectifier, water flow and change of water flow across a variety of functions, the construction specification is small, only 1/3 of the pipe nominal diameter for processing technology, and the vortex flowmeter made into an organic whole, not only need not also a takeover of extra section, can reduce the processing tube to take over the period of the provisions of the installation is very convenient.
In order to facilitate the use, the local display information type vapor vortex flowmeter of the rechargeable battery power supply system adopts the micro-power high-tech, and the lithium electric power supply system does not need to interrupt the operation for about one year, which saves the purchase and installation costs of the cable and the display information meter, and can display the instantaneous speed flow and accumulated flow of information locally.The temperature compensation all-in-one vortex flowmeter also contains a temperature controller, which can immediately measure the temperature of saturated water vapor and calculate the working pressure, thus showing the quality flow of information saturated water vapor.The temperature and pressure compensation model contains temperature and liquid level sensors for the measurement of vapor flow, which can immediately measure the temperature and working pressure of the vapor material, and then display the information of the standard condition of the vapor volume flow.
Measuring substance: vapor, liquid, vapor
Specification specification model flange card mounting specification select 25,32,50,80,100
Looper flange type specifications selected 100,150,200
Flow measurement range all normal flow measurement range Reynolds number 1.5×104 ~ 4×106;Vapor 5 ~ 50m/s;Liquid 0.5 ~ 7m/s
See table 2 for the measurement of liquid and vapor flow under normal flow measurement.The scope of steam flow is shown in table 3
Measurement precision level 1.0 level 1.5
Temperature of the measured substance: normal temperature -- 25¡æ ~ 100¡æ
High temperature -- 25¡æ ~ 150¡æ -- 25¡æ ~ 250¡æ
Output data signal monopulse working voltage output data signal low level 8 ~ 10V high level 0.7 ~ 1.3v
Monopulse duty cycle is approximately 50% and transmission spacing is 100m
Inrush current remote data signal 4 ~ 20mA, transmission interval 1000m
Ambient temperature :-25¡æ ~ +55¡æ ambient humidity :5 ~ 90%RH50¡æ
Material stainless steel plate, aluminum profile
Switching power supply DC24V or lithium 3.6v
Explosion-proof class iaiibt3-t6
Porcelain city Shanghai instruments co., LTD., is the world's leading instrument manufacturers, technology has always been the cornerstone of our company to survive, but we always use direct marketing, cancel the agent, so we can keep in close contact with customers, more important is to ensure that after-sales, delivery, price, etc., really do to ensure that the interests of the customer.
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