Product Description:
1、 Product Overview:
The LGX series wedge flowmeter is a new type of throttling differential pressure flow measurement instrument that can perform high-precision flow measurement in fluids with high viscosity, low Reynolds number, Reynolds number, and can be used up to 500. It has unparalleled advantages and irreplaceable functions in flow measurement scenarios with low flow rate, small flow rate, and large pipe diameter. This flowmeter has a simple structure, no movable parts, is not easily worn by fluids, has stable and reliable working performance, and has a long service life. Its measuring elements and pressure measuring device have a special structure that does not cause stagnation or blockage when the fluid passes through. The pressure loss is small, making it an ideal choice for high-precision flow measurement at low Reynolds numbers.
2、 Working principle:
The LGX series wedge flowmeter is a differential pressure flow instrument that utilizes Bernoulli's law of energy conversion in a closed pipeline, which states that in stable fluid conditions, the flow velocity in the pipeline is proportional to the square root of the differential pressure. Wedge flowmeter is a new type of flowmeter that began to gradually move towards practicality in the 1980s. Its detection component is a V-shaped wedge block (also known as a wedge-shaped throttling element), with its smooth top angle facing downwards, which is conducive to the smooth passage of liquids or viscous liquids containing suspended particles, without causing stagnation on the upstream side of the throttling element. When the fluid passes through the wedge flowmeter, a differential pressure proportional to the square of the flow rate is generated on the upstream and downstream sides due to the throttling effect of the wedge block. This differential pressure is led out from the pressure taps on both sides of the wedge block and sent to the differential pressure transmitter for conversion into an electrical signal output. After being calculated by a dedicated intelligent flow integrator, the flow rate value can be displayed.
Flow equation:
In the formula, qv - volumetric flowmeter, m3/s
C -- outflow coefficient;
ε - coefficient of expansion;
M - throttling area ratio;
D - Inner diameter of pipeline, m；
△ p - Differential pressure, pa；
ρ - density of the measured medium, kg/m3
Wedge type flow sensors have the function of correcting parameters such as flow coefficient, nonlinear error, temperature change, density change, etc; The measurement accuracy can reach 0.5%; It can have on-site display and standard current signal (4-20mA DC) output, which can be conveniently used for automatic control systems or networked with computers for automatic adjustment and control of flow or other parameters.
3、 Application scenarios:
The LGX series wedge flowmeter can perform high-precision flow measurement in fluid conditions with high viscosity and low Reynolds number (Reynolds number>500 can be used); Mainly used for flow measurement of high viscosity (heavy oil, residue oil, diesel, engine oil, etc.), industrial gas (coke oven gas, blast furnace gas, generator gas, city gas), hydrogen, nitrogen, air, steam, sewage liquid and other media. The measuring medium is as follows:
1. Gas
Gas and natural gas, including high moisture natural gas and non clean natural gas containing other impurities. Air, including air containing water, solid particles, and other suspended solids.
2. Steam
Saturated steam, superheated steam.
3. Liquid
Oils, including crude oil, fuel oil, coal tar, residual oil, paraffin oil, emulsified oil containing water, and polluted oil containing water and sand. Slurry, including oil slurry, iron ore slurry, pulp, mud, coal slurry, etc. Water, including purified water, sewage, industrial wastewater, river source water containing sediment and debris, etc. Various aqueous solutions, including highly corrosive acid, alkali, salt solutions, as well as solutions that are prone to crystallization and contain a lot of suspended solids.
4、 Main features:
1. Especially suitable for measuring media with high viscosity, low Reynolds number, suspended particles or bubbles;
2. The measurement accuracy is not affected or limited by the characteristics such as the dielectric constant of the fluid medium;
3. The wedge-shaped component has a special structural design, which has a guiding effect and prevents blockage;
4. It has compensation functions for fluid viscosity changes, temperature changes, density changes, etc;
5. Anti vibration, anti impact, anti dirt, anti corrosion, explosion-proof;
6. Wedge flowmeter has bidirectional flow measurement function;
7. High measurement accuracy;
8. Simple structure, sturdy, high reliability, easy installation, low operation and maintenance costs
9. No moving parts, no wear, no need to recalibrate for long-term use.
5、 Other features:
1. Suitable for measuring mud, coal tar pitch, coal water suspension, and other high viscosity fluids;
2. At very low Reynolds numbers in pipelines (even as low as Re=500), the square root relationship between flow rate and differential pressure can still be maintained. The maximum Reynolds number of the orifice flowmeter is much larger than that of the wedge flowmeter;
3. The wedge flowmeter calibrated by a single D.U has a high measurement accuracy (up to 0.5%), and the accuracy of an uncalibrated wedge flowmeter can also reach about 3%;
4. Simple structure, easy installation, use, and maintenance;
5. It can measure corrosive media. As differential pressure measurement uses a diaphragm type double flange differential pressure transmitter, corrosive media cannot enter the pressure pipe and differential pressure transmitter. Therefore, as long as corrosion-resistant materials are used to process wedge-shaped throttling components, the instrument can measure corrosive media.
6、 Technical parameters:
1. Flow measurement range:> 1:20；
2. Measuring pipe diameter: 25~1000mm (special orders can be placed if exceeding the range);
3. Measurement accuracy: Level 0.5, Level 1.6;
4. Reynolds coefficient usage range: 300~1x108;
5. Upper limit for measuring liquid viscosity: 500MPa S；
6. Work pressure range: ≤ 6.2MPa；
7. Installation connection method: flange connection; Welding connection;
8. Working environment temperature of flowmeter:- 20-+70℃；
9. Relative humidity of working environment: 15-85%;
10. Power supply voltage: 24V DC；
11. Communication method: RS485。
7、 Classification and structural composition of wedge-shaped flow sensors:
According to the scope of product supply and different output signals, wedge flowmeters can be divided into three categories:
1. Wedge shaped sensor;
Only the forming part of the differential pressure signal (wedge device part) is provided, and the differential pressure transmitter and flow display part are not provided. The output signal is differential pressure. Users can perform other configurations themselves.
2. Wedge shaped flow transmitter;
Composed of a wedge-shaped orifice plate flow sensor and a differential pressure transmitter. There are two types of structures: split installation and integrated installation.
a、 The split type wedge-shaped orifice flow transmitter consists of a D-U vertical wedge-shaped orifice flow sensor and a differential pressure transmitter. The pressure pipe connection between the wedge-shaped orifice plate flow sensor and the differential pressure transmitter is completed by the user themselves.
b、 Integrated installation means that the differential pressure transmitter is already connected to the wedge-shaped orifice plate as a whole when the product leaves the factory. After purchasing the integrated wedge-shaped orifice plate flow transmitter, users do not need to connect the pressure pipe again when using it. But corresponding flow calculators, pressure transmitters, and temperature transmitters must be connected.
c、 Composed of a combination of shut-off valves and other components. The connection combination between each part is completed by the user themselves. There are two types: explosion-proof and ordinary.
3. Structural composition:
The integrated installation consists of an intelligent display instrument and a wedge-shaped orifice plate device to form a wedge-shaped orifice plate flowmeter. It comes with high-quality differential pressure sensors, pressure sensors, and thermal resistance temperature sensors. The intelligent display instrument not only adapts automatically within the range of the differential pressure sensor, but also calculates various compensation coefficients such as the outflow coefficient C and the beam expansion coefficient ε online, truly achieving the expansion of the range while ensuring the accuracy of measurement. Using a large LCD screen to display cumulative flow, instantaneous flow, instantaneous pressure, and instantaneous temperature values on the same screen, without the need for manual switching. 4-20mA two-wire instantaneous flow output.
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