Venturi Flowmeter

Venturi Flowmeter

8 month ago

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Jiangsu Leitai Automation Instrument Co., Ltd.

 8 month year

Product details

The Venturi tube flowmeter is used in the measurement of combustion air, cold air, and gas (blast furnace gas, coke oven gas, converter gas) in hot blast furnaces in steel plants, and in the measurement of large diameter and low flow rate pipes for boiler primary air and secondary air in thermal power plants. Achieved good results.

Solve the problem of accurate measurement of various gas flows in current industrial enterprises with low pressure, large diameter and low flow rate. Fluid measuring device with wide measuring range and easy installation. The unique structural design and data processing methods are based on strict fluid mechanics, and are calibrated for real flow in a large national key wind tunnel laboratory. It can be widely used in the control and measurement of large-diameter fluids in petroleum, chemical, metallurgy, electric power and other industries.

Features

1. The requirements for installing straight pipe sections are low, which can effectively avoid or reduce the additional measurement uncertainty of the measurement system;

2. Can be used in various dirty media such as liquid, gas, steam and two-phase flow;

3. Small pressure loss, saving energy;

4. It has strong adaptability to media and can measure high-pressure and low-pressure fluids, high-humidity gases and various dirty fluids;

5. Simple structure, easy to install and maintain;

6. The Venturi flow meter is a standard throttling device designed and manufactured in accordance with the national standard GB/T2624 and calibrated in accordance with the national standard JJG640, and does not require calibration;

7. In the standard throttling device, it requires the shortest upstream and downstream straight pipe sections and the smallest pressure loss;

8. Stable performance and high reliability;

9. High measurement accuracy, equipped with a high-precision differential pressure transmitter to achieve accurate flow measurement

10. The measurement range (range ratio) is wide and can reach more than 10:1 without secondary meter software correction.

Technical parameters

Nominal diameter (mm): DN50 to DNl200 (~2600)

Nominal pressure (MPa): 0 25～4 0(～6 3)

Accuracy (uncertainty): ±01% ~ ±15%

Structural form

The axial section of the Venturi is shown in the figure. It consists of an inlet cylindrical section A, a conical constriction section B, a cylindrical throat section C, and a conical diffusion section E. The diameter of the cylinder section A is D, and its length is equal to D; the contraction section B is conical and has an included angle of 21o ± 1o; the throat C is a circular cylinder section with a diameter d, and its length is equal to d; the diffusion section E It is conical in shape and has a diffusion angle of 7o-15o.

5. Technical conditions

(1) Applicable industrial pipes: Nominal diameter of circular cross-section pipes:

DN=500~4000mm circular cross-section pipe: W×H=600×600~3600×3600mm and rectangular pipe with different width and height.

(2)Nominal pressure: PN≤6.4MPa

(3) Working temperature: below 400℃ (when it is above 400℃, please specify when ordering)

(4) Differential pressure value: 0~1.0, 1.6, 2.5, 4., 6.3, 10, 16, 25 and 40KPa

(5) Repeatability error: ±0.5%

(6) Stability: ±10Pa

(7) Accuracy level: 0.5 level, 1 level, 1.5 level, 2 level

(8) Sensor connection size: welded steel pipe G3/4", M20×1.5 or 1/2NPT

(9) Measuring medium, metallurgy: blast furnace gas, cold air, combustion air, flue gas, recycled gas, mixed gas

Electricity: primary air, secondary air, coal wind, etc.

Chemical industry: corrosive gases, air and other media

The principle of the Venturi effect is that when wind blows through a barrier, the air pressure near the port above the leeward side of the barrier is relatively low, resulting in adsorption and air flow. The principle of the venturi is actually very simple. It changes the air flow from thick to thin to speed up the gas flow rate, so that the gas forms a "vacuum" zone behind the outlet of the venturi. When this vacuum zone is close to the workpiece, it will produce a certain adsorption effect on the workpiece.

A-Compressed air inlet B-Nozzle C-Adsorption chamber inlet

The compressed air enters from the inlet A of the venturi tube, and a small part is discharged through the nozzle B with a small cross-section. As the cross-section gradually decreases, the pressure of the compressed air increases, and the flow rate also increases. `At this time, a vacuum is generated in the inlet of the D adsorption chamber, causing the surrounding air to be sucked into the venturi tube. Along with the compressed air, it flows into the diffusion chamber to increase the gas flow rate, and then the air flow oscillation is reduced through the silencer device.

Our main products are: Electromagnetic flowmeter, Energy meter, Vortex flowmeter, Pressure transmitters, Level gauge, Magnetic flap level gauge.