Pressure compensation vortex flowmeter

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Vortex street flowmeter has the LCD header pressure compensation, according to the real-time tempera…

Products overview:
ZW - LUGB seriesPressure compensation vortex flowmeterMainly 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 ℃ ~ + 350 ℃ 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 seriesPressure compensation in the measuring tube vertical vortex flowmeter insert a pillars, on both sides of the fluid through the pillars is alternately with the rules of the vortex, the spiral column is called the karman vortex street.The release of the karman vortex street frequency is related to the width of the fluid velocity and pillars, expressed by the type:
f＝St·v/d 
Type: - the release of the karman vortex street frequency f
St - coefficient (called, ha)
V - velocity
D - the width of the pillars
Karman vortex street release frequency f and is directly proportional to the velocity v, so by measuring the karman vortex street release frequency to calculate the instantaneous flow rate.
Stern lo ha is one of the important coefficient of vortex flowmeter.In its number of St 0.17 straight part of the material, the release of the vortex frequency is proportional to the velocity of flow, so check out the velocity v, frequency f can be obtained to calculate volume flow by v.
Vortex flow sensor be vortex frequency is applied to detect sensor by vortex alternately (probe) on in-situ stress in its internal piezoelectric element to check out.
Applications:
ZW - LUGB seriesPressure compensation vortex flowmeter can be widely used in large, medium and small various water supply and drainage pipe, industrial circulation, sewage treatment, oil and chemical reagents and compressed air, saturation and superheated steam, gas and all kinds of medium flow rate measurement.
Four, the main features:
1, the advantage is ant-vibration performance is very good, no zero drift, high reliability.
2, sensors, versatility is very strong, so that the sensor has good compatibility with advanced CNC processing equipment sensor table body and spiral body, etc., to ensure the machining accuracy, so that the parts (especially spiral body) versatility, thus truly will not affect by parts to replace the repeatability and precision of the sensor;Can produce a strong and stable vortex signal.
3, in a certain range of Reynolds number, flow characteristic from the fluid pressure, the influence of the temperature, viscosity, density, composition, is only involved in the body shape and size of the vortex.
4, output is proportional to the flow of the pulse signal or analog signal, no zero drift, high precision, convenient and computer connected to the Internet.
5, simple structure, no moving parts, high reliability, convenient in operation and maintenance.
6, detecting element, not contact with the media, stable performance and long service life, sensor detection probe with spiral body separate installation, and high temperature piezoelectric crystal seal in detecting probe, not contact with the measured medium, so vortex flowmeter has the characteristics of simple structure, high universality and high stability.
7, wide measuring range, range than can reach 1:10.
8, measure the volume flow without compensation, when the vortex of the output signal is actually with a linear relationship with velocity, namely is proportional to the volume flow.The purpose of the pressure and temperature compensation is to get the fluid density, multiply by volume flow to mass flow, if the measurement of the volume of a gas flow would be no need for compensation.
Five, the technical parameters:
1, the measured medium: liquid, gas, steam;
2, measuring range: (see table below);
3: (see table), nominal size of non-standard products can be customized according to user requirements special;
4, temperature range: piezoelectric - 40 ℃ ~ 350 ℃ capacitive - 60 ℃ ~ 450 ℃;
5, pressure specifications: PN1.6 Mpa;PN2.5 Mpa;Specifications can be customized special PN4.0 Mpa, higher pressure;
6, fan surrounded degree: normal range "extended range 1:15;
7, the pressure loss coefficient: Cd 2.6 or less;
8, system measuring accuracy: liquid, gas, plus or minus 1% of the value;
Steam steamed value plus or minus 1.5%;
Insert the value plus or minus 2.5%;
9, the power supply voltage: sensor + 12 VDC and + 24 VDC (optional) transmitter + 24 VDC;
Site type display instrument with 3.6 V lithium batteries;
10, output signal, sensor pulse frequency signal 0.1 ~ 3000 hz low level 1 v high level 6 v or more or less;
. Transducer two wire system 4 ~ 20 ma DC current signal;
11, allows vibration acceleration: piezoelectric capacitive acuities were 1.0 g 0.2 g or less;
: 12, the environment temperature sensors: - 30 ℃ ~ 65 ℃ transmitter, scene shows: - 10 ℃ to 50 ℃.
13, environment humidity: 5 ~ 85% relative humidity;
14 and the atmospheric pressure: 86 ~ 106 kpa;
15, signal remote transmission distance: 500 m or less.
16, signal interface: internal thread M20 x 1.5;
17, explosion-proof grade: (ia) Ⅱ CT2 - T5;
18, protection grade: regular IP65 diving IP68;
19, instrument material: instrument shell adopts aluminium alloy, the table body part adopts 304 stainless steel material, also can according to user requirements the use of special materials.

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.

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.

Eight, the requirements:
1, low maintenance - most of the vortex flowmeter are on the market with induction swirl hole or plug-in measurement, once the impurities embedded in the medium pressure hole or sensing element and the table body, the gap between the signal is weak or unstable.A good design should be not easy to plug part, thereby reducing amount of maintenance.
2, inductive components online replacement - some manufacturer of inductive components and vortex street close 2 for one, seemingly simple design to the actual use of inconvenience.Because once induction part failure, you need to medium to the pipe emptying replacement parts, after pressure relief effect production.Perfect design should be separated the two, so can replace the induction part alone, without emptying the media.
3, vortex flowmeter is vulnerable to vibration interference, well-designed vortex flowmeter can through hardware and digital signal processing to exclude interference, and the stability of the signal is obtained.
4, vortex flow meter before and after the installation of a hassle to very long straight section, some manufacturers can offer within the flowmeter reducing design, greatly reduces the user specifically MenWei vortex flowmeter with the demand of the straight pipe.
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 years of field application, we think the flowmeter zui suitable for relatively clean dry gas metering, gradually become small and medium-sized gas meters.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, standard of flow range profile: unit (m3 / h)

Twelve, selection of coding:

Thirteen,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.