Wedge flowmeter
Description
I. Product Overview:
LGX series wedge flowmeter is a new type of throttle differential pressure type flow measuring instrument, it can be in high viscosity, low Reynolds number, Reynolds number, the 500 can be used fluid to flow measurement with high resolution, small in low flow velocity, flow rate, pipe diameter of the flow measurement occasions have incomparable advantages and irreplaceable role. This flowmeter has simple structure, no moving parts, is not easy to be fluid wear, stable performance, reliable, long service life. The structure of its measuring element and pressure taking device makes it an ideal choice for high precision flow measurement at low Reynolds number, because the special fluid passes through without retention or blockage and the pressure loss is small.
Ii. Working principle:
LGX series wedge flowmeter is a differential pressure type flow meter, it is using Bernoulli's law of energy conversion in closed pipelines, that is: in stable fluid occasions, the flow rate in the pipeline is proportional to the square root of differential pressure. Wedge-shaped flowmeter is a new type of flowmeter gradually started to practice in the eighties, its detection piece is a V-shaped wedge (also known as the wedge throttling part), its smooth tip Angle is downward, so that it is conducive to the liquid containing suspended particles or viscous liquid through, not in the upstream side of the throttling part stagflation. Fluid through the wedge flow timing, due to the wedge throttling action, in its upper and downstream side produced a square relationship with the flow value of the differential pressure, the differential pressure from the wedge on both sides of the pressure outlet is sent to the differential pressure transmitter into electrical output, and then by the special intelligent flow integrator calculation, the flow value can be displayed.
Flow equation:
Qv ---- volume flowmeter, m3/s
C------ outflow coefficient;
ε----- coefficient of expansibility;
M ------ throttle area ratio;
D------ pipe diameter, m;
△ P ------ differential pressure, Pa;
ρ------ Density of the measured medium, kg/m3
Wedge type flow sensor has the function of flow coefficient, nonlinear error, temperature change, density change and other parameters correction; The measurement accuracy can reach 0.5%; Can have the field display and standard current signal (4~20mA DC) output, can be easily used in automatic control system or computer network, flow or other parameters of automatic adjustment and control.
Three, application:
The LGX series wedge flow meter can be used in high viscosity, low Reynolds number (Reynolds number > 500 can be used) for high precision flow measurement; Mainly used for high viscosity (heavy oil, residual 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 measurement medium is as follows:
1, gas,
Gas natural gas, including high moisture natural gas and non-clean natural gas containing other impurities. Air, including water, solid particles and air containing other suspended matter.
2, steam
Saturated steam, superheated steam.
3, liquid
Oil, including crude oil, fuel oil, coal tar, residual oil, paraffin oil, water-containing emulsified oil, water-containing and sand-containing dirty oil, etc. Grout, including oil pulp, iron pulp, paper pulp, mud, coal pulp, etc. Water, including clean water, sewage, industrial waste water, river source water containing sediment and debris, etc. All kinds of aqueous solutions, including all kinds of corrosive acid, alkali, salt solution and easy to crystallize, containing more suspended matter solution.
Iv. Main Features:
1, especially suitable for high viscosity, low Reynolds number, with suspended particles or bubble medium measurement;
2, the measurement accuracy is not affected and limited by the dielectric constant and other characteristics of the fluid medium;
3, wedge structure design is special, has the function of flow diversion, prevent clogging;
4, with fluid viscosity change, temperature change, density change compensation function;
5, vibration resistance, impact resistance, dirt resistance, corrosion resistance, explosion-proof;
6, wedge flow meter with two-way 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 be re-calibrated.
Five, other features:
1, suitable for measuring mud, coal tar pitch, coal water suspension and other high viscosity fluids;
2. In the case of 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 orifice flow meter can be the minimum Reynolds number is much larger than the wedge flow meter;
3, the single d.u calibrated wedge flowmeter has a high measurement accuracy (up to 0.5%), the accuracy of the uncalibrated wedge flowmeter can also reach about 3%;
4, simple structure, easy installation, use and maintenance;
5, the corrosive medium can be measured, because the differential pressure measurement is the use of diaphragm double flange differential pressure transmitter, corrosive medium can not enter the pressure tube and differential pressure transmitter, so as long as the corrosion resistant material processing wedge throttles, can make the instrument to measure corrosive medium.
Vi. Technical Parameters:
1, flow measurement range: > 1:20;
2, measuring pipe diameter: 25~1000mm (over the range can be special order);
3, measurement accuracy: 0.5, 1.6;
4, Reynolds coefficient range: 300~1x108;
5, the upper limit of liquid viscosity measurement: 500Mpa.s;
6, working pressure range: ≤ 6.2mpa;
7, installation connection: flange connection; Welding connection;
8, flow meter working environment temperature: -20-+70℃;
9. Relative humidity of working environment: 15~85%;
10, power supply voltage: 24V.DC;
11. Communication mode: RS485
Seven, wedge flow sensor classification and structure composition:
According to the range of product supply and output signal, the wedge flowmeter can be divided into 3 categories:
1, wedge sensor;
Only the forming part of 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. Other configurations are made by the user.
2, wedge flow transmitter;
It consists of a wedge orifice flow sensor and a differential pressure transmitter. There are two kinds of structures: split installation and integrated installation.
A. Split wedge orifice flow transmitter is composed of a wedge orifice flow sensor and a differential pressure transmitter. The connection between the wedge orifice flow sensor and the differential pressure transmitter is completed by the user.
B, integrated installation is the product factory has differential pressure transmitter and wedge orifice plate connected into one, users buy integrated wedge orifice plate flow transmitter, use without connecting the pressure tube. But must be equipped with the corresponding flow calculator, pressure transmitter and temperature transmitter.
C, stop valve and other parts of the combination. The connection combination between various parts is completed by the user himself. There are two types of explosion-proof type and ordinary type.
3. Structure composition:
Integrated installation by intelligent display device and wedge orifice plate device a wedge orifice plate flow meter. It comes with high quality differential pressure sensor, pressure sensor, thermal resistance temperature sensor. The e - type intelligent display instrument not only ADAPTS automatically in the range of differential pressure sensor, but also calculates all kinds of compensation coefficients such as outflow coefficient C and flow beam expansion coefficient ε on line, which can expand the range and ensure the measurement accuracy. It adopts large LCD screen to display cumulative flow, instantaneous flow, instantaneous pressure and instantaneous temperature without manual switching. 4-20mA two wire instantaneous flow output.