I. Product Overview:

LGX series wedge flowmeter is a new type of throttle differential pressure flow measuring instrument, it can be used in the fluid condition of high viscosity, low Reynolds number, Reynolds number, 500 can be used for high precision flow measurement, has incomparable advantages and irreplaceable role in the flow measurement of low velocity, small flow, large diameter. This flowmeter has simple structure, no moving parts, is not easy to be worn by fluid, stable performance, reliable, long service life. The structure of the measuring element and the pressure taking device is the ideal choice for high precision flow measurement under low Reynolds number conditions.

Ii. Working principle:

LGX series wedge flowmeter is a differential pressure flow meter, it is the use of energy conversion in the closed pipeline Bernoulli's law, that is, in stable fluid situations, the flow rate in the pipeline is proportional to the square root of the differential pressure. Wedge flowmeter is a new type of flowmeter that began to be applied gradually in the 1980s. Its detection part is a V-shaped wedge block (also known as wedge throttling part), and its smooth top Angle is down, which is conducive to the smooth passage of liquid containing suspended particles or viscous liquid, and will not produce stagnation on the upstream side of the throttling part. When the fluid passes through the wedge flow timing, due to the throttling effect of the wedge, a differential pressure which is square with the flow value is generated on its upper and downstream side. The differential pressure is extracted from the pressure opening on both sides of the wedge and sent to the differential pressure transmitter to be converted into electrical signal output. After the calculation of the special intelligent flow integrator, the flow value can be displayed.

Flow equation:

qv---- volume flowmeter, m3/s

C------ outflow coefficient;

----- coefficient of expansibility;

m------ throttling area ratio;

D------ Pipe diameter, m;

△p------ differential pressure, pa;

ρ------ density of measured medium, kg/m3

Wedge type flow sensor has the function of correcting flow coefficient, nonlinear error, temperature change, density change and other parameters. Measuring accuracy up to 0.5%; Can have the field display and standard current signal (4~20mA DC) output, can be easily used for automatic control system or computer networking, flow or other parameters automatic adjustment and control.

Three, application:

The LGX series wedge-shaped flowmeter enables high accuracy flow measurement in fluid situations with high viscosity and low Reynolds number (Reynolds number > 500 can be used); Mainly used for high viscosity (heavy oil, residue oil, diesel oil, oil, etc.), industrial gas (coke oven gas, blast furnace gas, producer gas, city gas), hydrogen, nitrogen, air, water steam, sewage liquid and other media flow measurement. The measured medium is as follows:

1. Gas

Gas and natural gas, including high moisture natural gas and containing other impurities unclean natural gas. Air, including air containing water, solid particles and other suspended matter.

2. Steam

Saturated steam, superheated steam.

3. Liquid

Oil, including crude oil, fuel oil, coal tar, residual oil, paraffin oil, water emulsified oil, water and sand containing sewage oil, etc. Grout, including oil pulp, iron pulp, pulp, mud, coal pulp, etc. Water, including clean water, sewage, industrial wastewater, river source water containing sediment and debris, etc. All kinds of aqueous solutions, including corrosive acid, alkali, salt solution and easy crystallization, containing more suspended matter solution.

Four, the main characteristics:

1, especially suitable for the measurement of high viscosity, low Reynolds number, medium with suspended particles or bubbles;

2, the measurement accuracy is not affected by the characteristics of the fluid dielectric constant and other restrictions;

3, wedge structure design is special, has the effect of diversion, prevent plugging;

4, with fluid viscosity changes, temperature changes, density changes and other compensation function;

5, anti-vibration, anti-impact, anti-fouling, anti-corrosion, explosion-proof;

6, wedge flowmeter with bidirectional flow measurement function;

7, high measurement accuracy;

8, simple structure, firm, high reliability, easy installation, low cost of operation and maintenance

9, no moving parts, no wear, long-term use does not need to re-calibrate.

V. Other Features:

1, suitable for measuring mud, coal tar pitch, coal water suspension and other high viscosity fluids;

2. Under very low pipeline Reynolds number (even as low as Re=500), the square root relationship between flow rate and differential pressure can still be maintained. The minimum Reynolds number of orifice flowmeter is much larger than that of wedge flowmeter.

3. The wedge-shaped flowmeter calibrated by single d.u has a high measuring accuracy (up to 0.5%), and the accuracy of the uncalibrated wedge-shaped flowmeter can also reach about 3%;

4. Simple structure, convenient installation, use and maintenance;

5, can measure corrosive media, because the differential pressure measurement is using diaphragm type double flange differential pressure transmitter, corrosive media can not enter the pressure guide tube and differential pressure transmitter, so as long as the corrosion resistant material processing wedge throttle parts, can make the instrument to measure corrosive media.

Vi. Technical parameters:

1, flow measurement range: > 1:20;

2, measuring pipe diameter: 25~1000mm (beyond the range can be special order);

3, measurement accuracy: 0.5, 1.6;

4, Reynolds coefficient range: 300~1x108;

5, measure the upper limit of liquid viscosity: 500MPa.S;

6, working pressure range: ≤6.2MPa;

7. Installation and connection mode: flange connection; Welding connection;

8, flowmeter working environment temperature: -20-+70℃;

9, working environment relative humidity: 15~85%;

10, power supply voltage: 24V.DC;

11. Communication mode: RS485.

Vii. Classification and structure of wedge flow sensor:

Wedge-shaped flowmeters can be divided into three categories according to the scope of product supply and output signals:

1. Wedge sensor;

Only the formation part of the differential pressure signal (wedge device part) is provided. The differential pressure transmitter and flow display part are not provided. The output signal is differential pressure. It is up to the user to perform other configurations.

2, wedge flow transmitter;

It is composed of wedge orifice plate flow sensor and differential pressure transmitter. There are two kinds of structure, split installation and integrated installation.

a, split wedge orifice flow transmitter is composed of d.u wedge orifice flow sensor and differential pressure transmitter. The pressure tube connection between the wedge orifice flow sensor and the differential pressure transmitter is completed by the user.

b. Integrated installation means that the differential pressure transmitter and wedge orifice plate have been connected into one when the product leaves the factory. After the user buys the flow transmitter of the wedge orifice plate, the pressure tube need not be connected again when using. But must be connected with the corresponding flow calculator, pressure transmitter and temperature transmitter.

c, the globe valve and other parts of the combination. The combination of connections between the parts is done by the user. There are explosion-proof type and ordinary type two.

3. Structure composition:

Integrated installation by intelligent display instrument and wedge orifice device a wedge orifice flowmeter. It comes with high quality differential pressure sensor, pressure sensor, thermal resistance temperature sensor. The E intelligent display instrument not only automatically ADAPTS to the range of the differential pressure sensor, but also computes various compensation coefficients such as outflow coefficient C and beam expansion coefficient ε online, which truly realizes the expansion range and guarantees the measurement accuracy. Large-screen LCD displays cumulative flow, instantaneous flow, instantaneous pressure and instantaneous temperature on the same screen without manual switching. 4-20mA two-wire system instantaneous flow output.