Plug-in vortex flowmeter
I. product overview
Zw-lucb series plug-in vortex flowmeters are mainly used for flow measurement of large-diameter gas, liquid and steam medium fluids in various industrial pipelines. They are characterized by small pressure loss, large range and high accuracy. They are almost unaffected by fluid density, pressure, temperature, viscosity and other parameters when measuring volume flow in working conditions. No moving parts, high reliability and low maintenance. Instrument parameters can be stable for a long time. Plug-in vortex flowmeter with piezoelectric stress sensor, high reliability, can be in - 20 ℃ ~ + 250 ℃ temperature range. It has analog standard signal and digital pulse signal output. It is easy to be used with computer and other digital systems. It is an advanced and ideal flow meter.
Ii. Working principle
ZW series - LUCB plug-in vortex street of vortex street flowmeter measurement head (i.e., small vortex flow sensor) is developed by using the theory of "the karman vortex street". In the vortex measurement header table body, the vertical insert a triangular prism spiral body, namely when the tables are in the medium flows through the body, is in the opposite direction in both sides of the triangular prism alternate with rules of karman vortex street, the signal frequency of vortex is made of the piezoelectric element detection head, detected on one side of the separation of the vortex frequency proportional to the flow of the medium speed, see formula f = V * St/d / 1-1.27 d
Where: vortex separation frequency on the side of f-trigon, (Hz);
St-strohard series constant;
V-- average velocity in the pipeline, (m/s);
D -- characteristic width of triangular column, (m);
D-- measure the inner diameter of the head, (m).
Through a large number of experimental tests, the instrument coefficient K of the vortex street measuring head is determined. The formula is as follows:
K0 = f/V
Where: k0-measuring head instrument coefficient, (1/m);
V point - measures the velocity at the head point, (m/s).
According to the relationship between the flow velocity V and the flow in the pipeline, the instrument coefficient KT (1/m3) of the plug-in vortex flow sensor under different pipelines can be determined, so as to determine the average flow velocity and volume flow in the pipeline.
Iii. Application:
Zw-lucb series plug-in vortex flowmeters are widely used in the measurement and control of superheated steam, saturated steam, compressed air and general gas (oxygen, nitrogen, hydrogen, natural gas, gas, etc.), water and liquid (such as water, gasoline, alcohol, benzene, etc.) in petroleum, chemical, metallurgy, heat, textile, paper and other industries.
Iv. Main features:
1, the use of micro power consumption high-tech, high technology content, stable performance, high precision, long life, technology and components are imported.
2, simple and firm structure, no moving parts, high reliability, long-term operation is very reliable
3, seismic performance is good, zero drift, effectively eliminate the impact of external vibration.
4. The output is a pulse signal proportional to the flow, without zero drift.
5. The measuring range is wide and the range ratio can reach 10:1.
6. Liquid crystal display on site, instantaneous flow display, cumulative total display, percentage display, frequency display, no need to switch in turn.
7, local key setting, convenient parameter adjustment, no need of handheld communicator.
8. Small pressure loss, wide range of dynamic measurement, low operation cost and all-round energy saving.
9. Density calculation, temperature and pressure compensation calculation, and online inspection of compensation calculation formula.
10, 0-5khzpinlv output, 4-20ma output or HATR communication, Modbus protocol communication, can be connected with industrial automation system.
11. Sensor and instrument can be separated according to site requirements, and separate control and remote control can be implemented.
V. technical parameters:
1. Nominal diameter (mm) : DN300 ~ 2200 insert type;
2. Nominal pressure (MPa) : 1.6-4.0;
3, medium temperature (℃) : piezoelectric: - 40-450 ℃ (protocol order);
4. Ontology material: 1Cr18Ni9Ti, (supply of other materials by agreement);
5. Accuracy: 1%R, 1.5%R, 1FS; Insert: 2.5%R, 2.5%FS;
6. Power supply voltage: sensor: +12V DC, +24V DC; Transmitter: +24V DC; Battery powered: 3.6v battery;
7. Output signal: square wave pulse (excluding battery-powered type) : high level 5V, low level 1V; Current: 4 ~ 20mA;
8, explosion-proof marks: the Ann model: Exd Ⅱ ia CT2 - CT5 flameproof: Exd Ⅱ CT2 - CT5;
9. Protection level: ordinary IP65;
10, environmental conditions: temperature - 20 ℃ ~ 55 ℃, relative humidity 5% ~ 90%, atmospheric pressure of 86 ~ 106 kpa;
11. Applicable medium: gas, liquid, steam;
12, transmission distance sensor: zui up to 4 km, two wire transducer (4 ~ 20 ma) : load resistance Ω 750 or less.
Vi. Unique technical advantages
1, the use of advanced CNC equipment processing sensor surface and vortex body, to ensure the processing accuracy, so that the parts (especially the vortex body) of the universality, so that the replacement of parts will not affect the repeatability and precision of the sensor; Strong and stable vortex street signals can be generated.
2, the radiator structure USES the horizontal release type structure, compared with the vertical release type radiator structure of the flow meter, less heat will be transferred to the amplification part, and heat dissipation area is large, heat dissipation faster, so that the reliability of the sensor is higher, longer life;
3, through a long period of time to a large number of vortex street flowmeter waveform analysis and spectrum analysis, designed the ideal probe shape, wall thickness, height, probe rod diameter and piezoelectric crystal, associated with the use of advanced numerical control lathe processing, ensure the alignment and finish machining precision, with special craft processing, which can overcome the vortex flowmeter is the intrinsic self oscillation frequency of the signal of the impact of this disease. This is our unique technical advantage in the production of vortex flowmeter.
Vii. Installation method:
The vortex street measuring head is inserted into the specific position of the pipeline. By measuring the local flow at this position, the average flow velocity in the pipeline is calculated according to the distribution relation of the flow velocity in the pipeline section. It is composed of a converter, insert rod assembly, ball valve (according to the demand), with a diameter of 100, the vortex street measurement head.
Viii. Installation steps
1, in the need to install the flow meter is directly above the pipe (horizontal pipe has this requirement), cut a slightly less than 100 hole, remove the burr;
2. Put the matching short pipe with flange at one end on the top of the hole, keep the short pipe perpendicular to the pipe passage, and weld firmly;
3, put a gasket, insert the flow meter, flange connection, if there is a ball valve at this time, should first put the ball valve on the short pipe connection, then open the ball valve, insert the flow meter;
4. Ensure that the flow meter has a straight pipe section of more than 15D in front and 5D behind (D is the inner diameter of the pipe).