Steam vortex flowmeter

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Steam pressure loss small vortex flowmeter, wide range, high precision, working condition of the mea…

Products overview:
ZW - LUGB seriesSteam vortex flowmeterBrand-new design concept, the temperature, pressure, flow rate signal collection at an organic whole, through the intelligent digital processors will be three kinds of mixed signal processing output a compensation after standard flow, so as to realize the temperature of gas, steam pressure compensation function.The adoption of intelligent integration design concept, therefore, the hydrogen flow meter has the characteristics of compact structure, easy installation and use of maintenance.It is used under certain conditions of fluid flow will generate oscillation, and the frequency of the oscillation and the flow rate is proportional to the principle of design.When the flow cross section must flow rate is proportional to the volume flow guide.Therefore, measuring flow oscillation frequency can be measured.

Second, the working principle:
ZW - LUGB seriesSteam the principle of vortex flowmeter is by the design in the flow field in the vortex, 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 seriesSteam 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 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: 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.

Vi.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, and GPRS communication devices, converters, 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, design front end must have at least 10 times the 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, selection of key points:
Correct selection to ensure that the use of vortex flowmeter is better.Choose what kind should be based on the medium of the measurement of physical properties and chemical properties to decide?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.
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, flowmeter 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.

Twelve, 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.
13, the 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.

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.