Card type vortex flowmeter

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Card mounted principle of vortex flowmeter is based on karman vortex closed pipe fluid flow measurem…

Products overview:
ZW - LUGB series card mounted vortex street flowmeter is a kind of common structure form, the table itself without connecting flange, when connected to the pipe, the flow meter card is installed between the two pieces of special flange, bolts can be used again.Is characterized by small volume, simple and compact structure.When I was in providing products of the company, at the same time provide special flange and bolt, so the user does not need to buy on the market, save a lot of unnecessary trouble.Products are both basic and compound type, basic measuring single * signal;Compound can be realized at the same time temperature, pressure, flow rate measurement.Each type has overall, fission structure, in order to adapt to different installation environment.
Second, the working principle:
ZW - LUGB seriesCard of vortex flowmeters are mounted in the measuring tube vertically inserted 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 seriesCard type vortex flowmeter can be widely used in large, medium and small pipes of various types of water supply and drainage, 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, can measure the steam, gas, liquid and the volume flow to mass flow.
2, dismantling the can realize does not block the flow sensor, which can realize the amplifier and sensor separation (separation distance of 15 m).
3, USES the interference elimination circuit and anti vibration sensing head, make the instrument has certain environmental vibration resistance.
4, small pressure loss, wide range, range of 10 to 40 times.
5, no mechanical moving parts, long-term stability and simple structure is convenient for installation and maintenance.
6, measurable medium temperature up to + 350 ℃ (+ 450 ℃).
Five, the technical parameters:
1, the measured medium: liquid, gas, natural gas, steam (saturated steam and superheated steam);
2, measuring range: Reynolds number is 5 x 103 ~ 7 x 106
3, normal measuring range: Reynolds number is 2 x 104 ~ 7 x 106
4, measure velocity range: liquid 0.5 ~ 7 m/s gas 4 ~ 35 mm/s steam 7 ~ 70 m/s
5, by measurement of body temperature: - 40 ℃ ~ + 300 ℃
6, by measurement of body temperature: 1.6, 4, 25 mpa
7, accuracy: level 1, 1.5, 0.5 (by nonlinear dressing can reach 0.5);
8, repeatability: 0.2% of the indicated value;
9, table body materials: ICr18Ni9Ti;
10, the pressure loss: delta (r = 1.2 * 10-6 V2 type: delta r - P - pressure loss measured the fluid density (Kg/m3) v - tube average flow velocity (m/s) ambient temperature: - 20 ℃ ~ + 55 ℃ (special request order)
11, environment humidity: 90% RH or less
12, atmospheric pressure: 86-106 kpa
13, external power supply source: 3.6 ~ 224 VDC
Power source: within 14, 3 ~ 4.5 VVDDC
15, working power supply: 80 / A
16, working voltage: 2.7 ~ 3.6 v
17, working frequency: 0.1 ~ 3000 h
18, signal remote transmission distance: 100 mm
19, signal output: pulse output (power source) 4 ~ 20 madc output current (two wire system for 24 VDC power supply) pulse output and the output current can only choose one way.

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 sensor can be installed indoors, can also be installed in the outdoor.Environmental conditions to conform to the requirements.
2, sensors should be installed in a horizontal, vertical or inclined (fluid flow from bottom to top) and its corresponding pipe nominal diameter.
3, sensors installed on a mechanical vibration of pipeline should be avoided.Should be considered when the vibration is inevitable, at about 2 dn from sensor before and after the straight pipe and fixing racks.
4, avoid install the sensor sensing has strong electromagnetic interference, thermal radiation, corrosive gas, the space is little, and maintenance is not convenient.
5, when measured medium contains many impurities, at the request of straight pipe upstream from sensors mounted outside the length of the filter.
6, either upstream or downstream of the sensor should be configured with a certain length of straight pipe, straight pipe inner surface should be clean, smooth, no obvious convex concave, fouling and peeling phenomenon.Its length should conform to the requirements of figure 2.Installation of the liquid sensor, near the pipe should be filled with liquid to be tested.
7, straight pipe diameter as far as possible consistent with the sensor size, if not consistent, slightly larger diameter than the sensor size should be adopted, the error to 3% or less is not more than 5 mm.
Nine, field 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.

Ten problems need to pay attention to during using, debugging:
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.
Eleven, 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 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.

Twelve, selection guidelines:

Determine the structure of the sensor

1, connection mode: flange card mounted body without flange (table) or flange connection type (table body itself with flange).General advice to choose flange mounted, because of its compact structure, low price, and short delivery cycle.

2, the structure type: one-piece structure and split type structure.Generally USES the one-piece structure, only on special occasions, adopts the split type structure (such as: medium at high temperature, environmental temperature or humidity is high, with the scene display for easy reading).

3, display mode: no scene shows, with the scene display and carry only the scene.Scene shows refers to on the header is equipped with LCD display, can display the cumulative flow and transient flow parameters, such as.

4, the signal output way: the pulse signal output and 4 ~ 20 ma current standard signal output.The pulse signal output normally recommended, because directly and vortex shedding frequency corresponding to the pulse signal, without conversion, has a zui high accuracy;At the same time, in the usual transmission distance, pulse signal transmission effect is better.Standard and is commonly used in current signal output terminal or control system of the flow measurement system.

5, explosion-proof forms: the explosion proof type and safety explosion-proof type.If the medium to be measured is flammable and explosive substances or measuring environment is flammable and explosive substances, should choose explosion-proof type.

Determine the configuration of the vortex flowmeter:

1, the density compensation:

When measuring the mass flow rate of steam, due to its density changes with the change of temperature and pressure, so to compensate for steam, at any time with a platinum thermal resistance and pressure transmitter with vortex sensor with mass flow measurement system.There is a measurement of saturated steam and superheated steam, to be stable if the temperature and pressure to reduce the equipment cost, can also according to the working state, by setting a fixed value density compensation.Other media can according to the actual situation of mass flow measurement system.

2, of intelligent flow totalizer.especially options:

Requires only display parameters, can choose digital display or LCD display; intelligent flow totalizer.especiallyNeed to trace the historical data, with memory function, should choose intelligent flow settlement paperless recorder;Measure the full and steam, should choose with automatic temperature compensation density or pressure; automatic compensation of density flow totalizer.especiallyMeasurement of superheated steam, should choose along with temperature and pressure compensation density flow integrating instrument;Using the remote communication, should consider intelligent flow totalizer.especially with RS485 and RS232 communication interface.Requirements and control system of the flow measurement system, intelligent flow integrating instrument should take 4 ~ 20 ma standard current signal output interface;

When needed, should configure a backup power supply, so that all of a sudden power failure meter can be measured normal.When needed, should with meter box, place the intelligent flow integrating instrument, instrument box, with a lock made of intelligent flow totalizer.especially set parameters cannot be adjusted freely, with anti-theft function, at the same time, the instrument is equipped with protection circuit in the oven, play a role of protection of intelligent flow totalizer.especially.

3, remote monitoring: in need multi-point measurement, distribution area is larger, the need for real-time monitoring, can use the GSM/GPRS communication network or wireless private network remote traffic monitoring system, realize real-time monitoring and management of the pipeline flow.

4, the determination of the calibre of the sensor, the sensor diameter is different, its measuring range is different, and each kind of caliber its measuring range as the measured medium type and condition of the change of temperature, pressure change, first determine the medium under the working condition.

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

14, selection of coding:

15,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.