Gas vortex flowmeter

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Gas vortex street flowmeter is characterized by small pressure loss, wide range, high precision, wor…

Products overview:
ZW - LUGB seriesGas vortex flowmeterAccording to the principle of Carmen (Karman vortex street is mainly used in industrial pipeline medium fluid flow measurement, such as gas, liquid and vapor, and other media.Is characterized by small pressure loss, wide range, high precision, working condition of the measurement volume flow is almost not affected by the fluid density, the influence of the parameters such as pressure, temperature, viscosity.No moving mechanical parts, so high reliability, small amount of maintenance.Instrument parameters can be long-term stability.Vortex street flowmeter using piezoelectric stress sensor, high reliability, can be in - 20 ℃ ~ + 250 ℃ temperature range.There are standard signal simulation and digital pulse signal output, easy with the computer and digital systems, is a more advanced, the ideal measuring instrument.

Second, the working principle:
ZW - LUGB seriesGas vortex street flowmeter measurement principle is by the design in the flow field in the vortex body, detection probe and the corresponding electronic circuit, etc.When the fluid flows through the spiral body occurs, it is formed on both sides of the two rows of vortex variations, this vortex is known as the karman vortex street.On the basis of the theory of karman vortex street and proposed the karman vortex street frequency is proportional to the velocity of the fluid, the relation between the frequency and velocity are presented:
F = St * V/d type:
F vortex frequency (Hz)
V vortex occurred body on both sides of the average flow velocity (m/s)
St, luo hall coefficient (constant)
These variations of vortex is formed a series of variations of negative pressure, the pressure on detecting probe, and produce a series of alternating electric signals, after dealing with the preamplifier conversion, plastic, amplification, the output is proportional to the vortex synchronous pulse frequency signal (or standard).
Applications:
ZW - LUGB seriesGas main vortex flowmeter is widely used in petroleum, chemical industry, metallurgy, machinery, paper, and the city pipe heating, gas and other industries a variety of single-phase fluid process gas, steam and other low viscosity measurement and energy saving management.

Four, the main features:
1, can accurately measure within wide flow range of gas, liquid and steam flow and not affected by fluid physical properties;
2, not affected by temperature, pressure, not easy to plug at the same time, not easy card, not easy to scale, high temperature resistant, high voltage;
3, safety explosion-proof, suitable for bad environment;
4, have no moving parts, no hole aperture design, product without any abrasion, corrosion resistance, dirt without mechanical maintenance, long service life;
5, using micro power consumption of new and high technology, a battery-powered scene shows type flowmeter, power is not running for more than two years;
6, temperature, pressure compensation integrated design;
7, current output are electrical isolation, good common-mode interference suppression ability;
8, also showed flow values and cumulative flow value, don't have to take turns to switch;
9, using vibration probe, the effective elimination of the influence of external vibration;
10, using split type signal converters, cable is 100 meters long;
11, than a wide range of those days;
12, instrument structure design is reasonable, wide dynamic range, small pressure loss;
13, table body is made of stainless steel material, can be applied to measurements of corrosive medium;
14, the liquid crystal display, pulse, 4 ~ 20 ma output 485 newsletter, or can be connected to the industrial automation system.
Five, the technical parameters:
1, the measured medium: gas, liquid and vapor;
2, connection mode: flange card mounted, flange, plug-in;
3, diameter specifications flange mounted caliber select 25,32,50,80,100;
4, the flange connection type choose 100150200;
5, flow range (see chart flow range)
6, normal measuring velocity range Reynolds number 104 ~ 1.5 x 4 x 106;Gas 5 to 50 m/s;Liquid 0.5 ~ 7 m/s;
7, measurement accuracy 1.0 magnitude 1.5 on the Richter scale;
8, measured medium temperature: room temperature - 25 ℃ ~ 100 ℃, high temperature - 25 ℃ ~ 150 ℃ to 25 ℃ ~ 250 ℃;
9, high output signal pulse voltage output signal level 8 ~ 10 V low level from 0.7 V to 1.3 V;
10, pulse duty ratio is about 50%, transmission distance is 100 m;
11, pulse current 4 ~ 20 mA remote transmission signal, transmission distance is 1000 m;
12, instrument: using the environment temperature 25 ℃ ~ + 55 ℃, humidity: 5 ~ 90% RH50 ℃;
13, the material of stainless steel, aluminum alloy;
14, DC24V power supply or lithium battery 3.6 V;
15, explosion-proof grade this Ann model iaIIbT3 - T6, protective class IP65.

Six, pipe requirements:
1, the requirement for straight pipe:
In order to ensure that the instrument, accurate to run normally, sensor must have a certain straight pipe upstream and downstream of the installation points, to adjust the flow field, as shown.

Figure 1: concentric contraction tube;
Figure 2: the concentric expansion tube;
Figure 3: a 90 - degree Angle;
Figure 4: the same plane of two 90 - degree Angle;
Figure 5: different plane of two 90 - degree Angle;
Figure 6: regulating valve should be installed downstream of the sensor in 5 d to the distance, if the sensor must be installed in the upstream, the sensors should be not less than 50 d upstream, straight pipe section downstream straight pipe section should be not less than 5 d.
2, the requirement of pipe:
A, upstream and downstream piping diameter D and the same as the sensor inner diameter DN, its difference satisfy the following conditions: 0.95 DN D 1.1 or less or less DN.
B, piping shall be concentric with sensor, coaxial degree should be less than 0.05 DN.
C, gasket not protruding into the pipe, the inner diameter slightly larger than sensors.
D, if you want to stop inspection and cleaning the sensor, the by-pass pipe should be set up,As shown in the figure below.

 
3, the requirement of pipe vibration:
Sensors to avoid installed on the strong pipeline vibration, if necessary to install, shock absorption measures must be taken, respectively at the upstream and downstream of sensor 2 d piping fastening device, and vibration-proof pad.
Special note: in the air compressor exit strong vibration, cannot install the sensors, shall be installed after the gas storage.
4, demand for air condition:
A, the gas to be tested for single phase pipe flow, continuously flowing through a pipe.
Before b, the gas flows through the flowmeter, the flow rate must be parallel to the pipe axis, can not have vortex flow.
C, flow should be a subsonic, a pulse, its flow change slowly over time.
5, the flowmeter installation requirements:
Vortex street flowmeter to process the installation and use of the special requirements of environment is not too much, but any kind of flow measurement instrument has such a common, as far as possible to avoid vibration and high temperature environment as flow interference elements (such as compressor, separator, pressure regulating valve, reducer, and pipe, elbow, etc.), keep straight pipe before and after the instrument inside sleek straight, ensure to clean single-phase fluid measured medium, etc.

Seven, installation specification management:
Intelligent vortex flowmeter standard installation, to use the department in the subsequent management provide strong technical support, put forward the following specific requirements of the construction unit, after years of validation effect is very good.
5, smooth instrument ark need concrete pier base, instrument protection grade for outdoor cabinet, the ark with insulating layer to prevent sun point-blank, ark with water proof function.

14, standard of flow range profile: unit (m3 / h)

15, selection of coding: