Pulse type vortex flowmeter

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Pulse type vortex flowmeter is according to the principle of Carmen (Karman vortex street research p…

Products overview:

ZW - LUGB seriesPulse type vortex flowmeterOutput pulse frequency of the signal is not affected by fluid physical properties, and composition change, namely the instrument coefficient in only within a certain range of Reynolds number and swirl through the body and the shape size and so on.But as flow meter need to be detected in the material balance and energy metering mass flow rate, the flow meter should be monitored at the same time the output signal of the volume flow rate and fluid density, fluid property and has a direct influence on flow metering or components.

Vortex flowmeter is based on the principle of karman vortex closed pipe fluid flow measurement of new type flowmeter.Medium because of its good adaptability, no compensation can be directly measured temperature and pressure steam, air, gas, water, and the operation condition of the liquid volume flow, temperature, pressure sensor to measure standard conditions and volume flow to mass flow, is the ideal substitute of orifice flowmeter.

Second, the working principle:
ZW - LUGB series pulse type vortex flowmeter is by the design in the flow field in the vortex, detecting sensor 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 series pulse type vortex flowmeter is widely used in petroleum, chemical industry, metallurgy, machinery, paper, and the city pipe heating, water supply, gas and other industries of all kinds of low viscosity liquid, gas, steam, etc of single-phase fluid process 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 zui, 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, appearance size:

Seven, 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.

Eight, installation requirements: 
1, the vortex street only one-way measurement, pay attention to when installation to ensure medium flow direction and flow meter in the same direction indicated by an arrow. 
2, installation for the vertical installation, medium from bottom to top through the flow meter.The flow meter installed in vertical pipe runs, from bottom to top direction of flow. 
When mounted horizontally, and 3 meter must be installed in the high of the whole system, and to ensure that the outlet pressure corresponding;Do not install in pipeline zui high, because of zui highs tend to gas accumulation, the pipe is not full, export direct vent. 
4, when measuring high temperature fluid, used in a vertical installations as far as possible;If have to horizontal installation, please send the flow transmitter partial vertical downward, or horizontal lateral loading, avoid high temperature;Pay attention to the installation location of air flow or well ventilated. 
5, straight pipe requirements: at least ensure before 15 times the pipe diameter, flow meter after 5 times the pipe diameter.Before such as flowmeter bend, indentation, expand the interference sources, such as need to ensure before 30 to 40 times the pipe diameter, flow meter after six times the pipe diameter.Flow meter should be installed in regulating valve, pressure or temperature sensors upstream. 
6, when installation, pay attention to the pipe size should be slightly bigger than or equal to the inner diameter of the instrument. 
7, the use of seals, pay attention to the sealing ring inside diameter should be slightly greater than or equal to the inner diameter of the instrument, sealing ring center located in the heart of the pipeline. 
8, cable entry seal instrument electric connection, must pay attention to in line hole sealing.Must choose according to meter cable entry model corresponding sealing interface (M20 Χ 1.5;1/2 "NPT.G1/2 '), and properly, closely installation.No seal joint, or careless, can not meet the sealing effect.

Need to pay attention to during the period of nine, debugging, using question:
1, flowmeter, on-site installation, maintenance, must abide by the "explosion-proof gas do not open" warnings, and in the open before turn off the power supply.
2, vortex flow meter used in outdoor, suggestion and side shields.
3, shall not be arbitrarily fixed part loosen the flowmeter.The protection of the pressure sensor.Users in the use of traffic time, should pay attention to the flow pressure overload value of pressure sensor is rated working pressure of 1.5 times (that is, the media zui high pressure of 1.5 times).Selection should be within the prescribed flow range, prevent overspeed operation, in order to obtain the ideal accuracy and ensure the normal service life.(due to pressure test, purging pipes or exhaust overdrive, and turbine operation in the reverse flow meter can cause damage)
4 when put into operation, the vortex street flowmeter, should slowly open valve, prevent damage of instantaneous flow and the turbine.Add lubricant should be according to the sign, the number of refueling depends on temperament clean degree, usually 2 ~ 3 times a year.
5, vortex street flowmeter runtime or alternate internal related parameters are not allowed to open the rear cover, otherwise will affect the normal operation of the meter.
Ten, install and use should be paid attention to in the items:
Vortex street no mechanical moving parts, small size, corrosion resistance, stable performance, can be directly display medium work pressure, temperature, flow rate and volume under standard state, wide range, the advantages of small measurement error, has been widely used in oil and gas well production measurement and gas sales.In field application over the years, we believe that the meter is suitable for relatively clean dry gas metering, gradually become small and medium-sized gas metering.To guarantee the accuracy of the flowmeter measurement, reduce the measuring error, please note:
1, the selection of reasonable
Don't make the actual zui small flow meter QVmin below the selected through runoff flow range limit.
2, installation is correct
Upstream of the vortex flowmeter should have at least 10 d measuring straight pipe length.Straight pipe inner surface should be smooth, cannot have the steps, more smooth connecting flange weld, flange gasket can't into the pipe.Don't put the wrong installation direction of the flow meter.Tests showed that: all the unreasonable installation, will lead to the flowmeter measurement value is low.
3, away from the source of shocks, or install piers in upstream or downstream flow meter, in order to avoid the influence of the pipeline vibration.Avoid strong magnetic field disturbance to the flow meter chip.
4, temperament is relatively clean
Especially not a gas liquid two phase flow;Temperament is dirty, should clean instant flow meter.
5, and reduce the influence of flow pulsation
It can be installed in front of the flow meter buffer tank, or extended length of straight pipe upstream of the flow meter, computation.
6, timely flowmeter for metrological verification, to ensure accurate and reliable value.

Eleven, matters needing attention:
1, special flange and straight pipe welding can't with the sensor.
2, when installation should make the flow of sensor mark the direction of flow and the pipe.
3, before the installation of sensor and the flange must be put away in sealing ring grooves.The location of the pressure and temperature measurement point, pressure downstream of the sensor in 3 ~ 5 dn, temperature measuring points in the downstream of 5 ~ 8 dn.
4, when measuring high temperature medium, do not use heat insulation material to wrap around the sensor link rod.

Five, connection of shielded cable, should as far as possible away from the interference of strong electromagnetic field.Absolutely not allowed with high voltage cable laying, shielded cable to shorten as far as possible, and shall not be volume, in order to reduce stray inductance, length should not exceed 200 m.
6, before installation of sensors, pipeline cleaning must be conducted.Flow after rinse tube impurities, avoid clogging sensor.Measuring liquid pipe must be full of measured liquid, prevent the interference of bubbles.
7, measuring gas pipelines to prevent the interference of reservoir fluid.Installation position as shown in figure 5.Replace the probe body under the high temperature and high pressure, it must be safe operation, high temperature protection.After cooling step-down replaceable probe at the bottom of the safety conditions.
Twelve, installation specification management:
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.
1, with 4 ~ 20 ma output, pulse output.
2, GPRS remote transmission device with pulse input, input 4 ~ 20 ma.
3, with power supply prevents thunder and lightning protection (4 ~ 20 ma) signal.
4, instrument cabinets for: ark with UPS power supply, open and the socket, the GPRS communication devices, intelligent vortex flowmeter converter such as concentrated installation and lock.
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.
6, domestic demand has left side table well enough straight pipe, facilitate intelligent vortex flowmeter test, compare and follow-up management.
7, the design of intelligent vortex flow timing front must have at least 10 times of nominal menstruation (dn) 10 straight pipe, the back-end must leave more than 5 dn straight pipe, to ensure accurate measurement.
8, shall be installed in accordance with the specifications and after the installation need measuring grounding, grounding resistance should be under 10 Ω.Equipotential connections using multiple strands of copper wires, cables should be greater than or equal to 16 was;Instrument grounding line using multiple strands of copper conductor, cable requirement was greater than or equal to 6.Grounding standard see GB50343-2009 "technical specification for building electronic information system lightning protection.
13, selection of points:
Correct selection to ensure that the use of vortex flowmeter is better.Should choose what kind of vortex street flowmeter is based on the current body to determine the physical properties and chemical properties of the medium?Make the size of vortex flowmeter, flow range, lining materials, electrode materials and output current, etc?To be the nature of the flow volume and flow measurement requirements.
1, precision function
Precision grade and function in accordance with the requirements of measurement and choose the instrument using fine grade, cost-effective.Such as for trade settlement, product transfer and energy measurement occasions, should choose high precision grade, such as 1.0, 0.5, or higher level;Used in process control, according to the requirements of control choose not with precision grade;Some just check process flow, without having to do precise control and measurement, can choose lower precision grade, such as 1.5, 2.5, 4.0, and even then you can choose cheap plug-in vortex flowmeter.
2, medium can be measured
Medium velocity and diameter, full scale measurement generally medium, the full flow of vortex flowmeter can measure medium velocity in 0.5-12 m/s within the scope of selection, range is wide.Choose different instrument specifications (diameter) and process piping, the same shall consider whether measuring flow range within the scope of the flow velocity, namely when the pipeline flow rate is low, can not meet the requirement of the flow meter, or under the velocity measurement accuracy of the quasi cannot guarantee, the need to reduce the size instrument, which carry high tube flow velocity, measurement results are satisfied.
3, the selection of vortex flow transmitter
In saturated vapor measurement using VA type piezoelectric vortex flow transmitter, due to the vortex flow meter range wide, therefore, in practice, the measurement of saturated steam flow main consideration shall not be less than the lower limit of vortex flowmeters, that is to say, must satisfy the fluid flow rate shall be not less than 5 m/s.According to the size of the YongQiLiang chooses different caliber of vortex flow transmitter, rather than with the existing technology to choose transmitter diameter pipe size.
The choice of 4 pressure transmitter, pressure compensation
Because of the saturated steam pipe length, pressure fluctuation is bigger, pressure compensation must be used, considering the pressure, temperature and density, the relation between measurement using pressure compensation, because the pipeline saturated steam pressure in the range 0.3 0.7 MPa, pressure transmitter ranges 1 MPa.
5, display instrument selection
Display instrument intelligent flow display, a voltage compensation, the instantaneous flow and cumulative flow integrating function.

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

15, selection of coding:

16,Order to choose selection guidelines: 

Name and model number of 1, 1), (2) the diameter, flow range, (3) whether or not to bring the attached so that we can correct selection for you, (4) using pressure, (5) the use of medium temperature.

2, if has been selected by design units in the way of vortex street flowmeter types, please press type vortex flowmeter directly order from our sales department.

3, when using occasions is very important, or the environment is complex, please try to provide the design drawings and detailed parameters, by wei experts in our audit checks for you.

After-sales service commitment:

1, from the date of signing of the contract, I in the way provided for products of the company offers free maintenance and maintenance service, commitment to lifelong maintenance service;

2, jiangsu wei measurement and control instrument co., LTD. Sales manager will be in regular contact with customers, understand the usage of products, and solve the problems of the customers to use in the process of produce, free of charge to provide technical support;

3 the man-made damage is found, the warranty period, our company is responsible for the maintenance, and the resulting maintenance fee;

4, product quality problems or are not satisfied with product, the user can choose unconditional return, wei tt&c don't charge any fees, appear quality problem, bear the freight back and forth.