working principle
The vortex flowmeter is used to measure the gas, steam and liquid in the full pipe state, and the measurement is based on the Karman vortex principle.When the medium flows through the triangular prism at a certain speed, an alternate arrangement of vortex bands is generated behind both sides of the triangular prism, which is called 'Karman vortex'. Pressure pulsation is generated, so that the detection body produces alternating stress. Under the action of alternating pressure, the piezoelectric element packaged in the detection probe generates an alternating charge signal with the same frequency as the vortex, which is amplified by the pre-amplifier and sent to the intelligent flow calculation. The instrument is intelligently processed to realize the display of the instantaneous flow and cumulative flow of the fluid, and the communication and control of the flow data and the microcomputer system.
Within a certain Reynolds number range (2x10^4~7x10^6), the relationship between the release frequency of the vortex and the fluid velocity V and the width d of the upstream surface of the vortex generator can be expressed by the following formula:
In the formula, f-the release frequency of Karman vortex, Sr-coefficient (called Straw number), V-flow velocity, d-the width of triangular column.The Strouhal number is an important coefficient of the vortex flowmeter.In the straight part of Sr=0.16 of the number of curves, as long as the frequency f is accurately measured, the fluid flow rate V=f d/Sr can be measured, so as to achieve the purpose of measuring the fluid flow in the pipeline;
Namely: Q=3600xf/k·-----()(K-instrument factor, times/m3)
features
Good media versatility, can measure steam, gas and liquid;
Steam: saturated steam and superheated steam;
Liquid: water, softened water, gasoline, kerosene, diesel liquefied petroleum, liquid nitrogen, phosgene, alkanes, alkenes, alcohols, aldehydes and other chemical liquids;
·Gas: air, oxygen, nitrogen, natural gas, ammonia, chlorine, alkanes, alkenes, hydrocarbons and other gases;
The piezoelectric element is embedded in the probe, with stable performance;
The detection element does not contact the medium, the pressure loss is small and the service life is long;
·Intelligent integrated design to display instantaneous flow and cumulative flow;
The internal parameters of the micro-power dual power supply design are permanent;
Simple operation, just set the pipe diameter parameters and measuring medium to complete the basic debugging;
·Adaptive spectrum analysis technology improves digital processing, high precision, low power consumption, high anti-interference performance;
Wide flow measurement range;
Automatically judge the superheated and saturated state of steam, and accurately measure the steam quality;
RS485 communication has the function of industrial Internet of things, applies WiFi technology, online operation monitoring, software upgrade.
CKAS-FLVJ-R series public converter liquid crystal display screen composition
1. These five digits have several meanings
1.1 Q is displayed on the left, indicating instantaneous flow
1.2 The P displayed on the left indicates the pipeline gas pressure
1.3 mA is displayed on the right, indicating current
1.4 % is displayed on the right, indicating a percentage
There is no unit display in 1.5'7', and the five digits in '1' indicate the frequency of the vortex signal
1.6 Simultaneously display the five digits in PQ'1', indicating the frequency of the vortex signal, indicating the frequency value before the correction of the meter coefficient
2. Instantaneous flow intensity bar, there are a total of 20 small divisions in the full scale, and each division represents 5% of the full scale flow.
3.DNXXX indicates the diameter of the pipe to be measured, and it is used as the code display of the menu when the menu is selected.
4. These six digits have several meanings:
4.1 Total on the left indicates cumulative flow
4.2 T on the left represents the gas temperature in the pipeline
5. Indicates the cumulative flow unit:
ft cubic feet (volume) t: tons (mass) kg: thousand ft: grams (mass)
NL: standard liter (volume)
L: liter (volume) m3: cubic meter (volume)
X1000: The cumulative flow reading multiplied by 1000 is the real cumulative flow
6. Password lock status display and battery power status (battery powered type).
7. Indicates the instantaneous flow unit, the letter in front is the flow unit, and the following h, s, min, d are time.
There are many combinations of traffic and time, only the most commonly used combinations are introduced:
7.1 m3/h: cubic meter per hour
7.2 g/h: kilogram per hour
7.3 Nm3/h: standard cubic meter per hour
industry
Widely used in chemical industry, oil and gas, power plant, food and beverage, pharmaceutical, steel and metallurgy, paper industry, water, automobile industry and other related industries.
application
Widely used in the measurement of saturated steam and superheated steam, steam boiler monitoring, steam and hot water heat, industrial gas consumption measurement, compressed air system consumption measurement, compressor outlet monitoring air compressor FAD flow estimation, food, beverage and pharmaceutical The industry's SIP and CIP processes can be applied to measurements related to SIL2 level safety certification.
