Classification of differential pressure Venturi flowmeter
I. Characteristics of differential pressure Venturi flowmeter differential pressure Venturi flowmeter is a kind of differential pressure flowmeter, which is compared with traditional flow measuring instrument.
Its Measurement stability is good, accuracy can basically meet the demand, and it has certain application in reservoirs and a few water companies. The Venturi flowmeter consists of a Venturi tube (Save pieces)
And the flow rate is calculated by measuring the differential pressure before and after flowing through the saving part.
The savings of this kind of flowmeter have almost not improved, and have now reached the level of perfection and standardization. Second, the classification of Venturi Flowmeters: venturi flowmeters are divided into pipeline Venturi flowmeters and puncture Venturi flowmeters according to their different equipment methods. Pipeline Venturi flowmeters can be divided into standard Venturi flowmeters (General pipeline)
And rectangular Venturi flow meter. Rectangular Venturi flow meter is a built-in Venturi tube. It is mainly about measuring the flow of large pipe diameter, low flow rate and large flow of various gases in industrial enterprises, and has a common structural plan, real flow calibration was carried out in the national large-scale key wind tunnel laboratory.
It can be widely used in the operation and measurement of large-diameter fluids in petroleum, chemical industry, metallurgy, electric power and other professions.
Piercing Venturi flowmeter is mainly used for field application with too large caliber, short straight pipe of equipment or limited equipment position and low demand for flow measurement accuracy. It has convenient equipment debugging and does not need to cut pipe sections, low cost and other characteristics are currently commonly used to replace rectangular Venturi and wing wind measuring equipment for wind flow measurement.
According to different processing and manufacturing methods, it is divided into standard Venturi flowmeter for rough casting shortening section, Venturi flowmeter for mechanical processing shortening section and Venturi flowmeter for rough welding iron plate shortening section.
Three, Venturi flowmeter's primary characteristics: 1, simple structure, durable, stable function, not easy to block.
2. The pressure loss is small, which saves the power required for Flow Transportation, and can be used for measuring messy flow such as two-phase flow, mixed flow, low flow rate, large pipe diameter, special-shaped pipe, etc.
3. High accuracy, good repeatability, small pressure loss and short straight pipe. 3, in the diameter of 50-Within the scale of 1200, real flow calibration is not required. Beyond this scale, it is possible to compare planning and production.
When high precision is required, real flow calibration can be carried out.
4. The scale of the body equipment is relatively large. As for the appearance of large diameter, it is not convenient to transport the equipment. Standard orifice plate or piercing double Venturi flowmeter can be considered.
4. Principle of Venturi flowmeter: Venturi flowmeter is also called Classic Venturi tube and classic Venturi tube. It is used to be called Venturi tube and standard Venturi tube.
It is a kind of standard saving equipment, which is developed according to Venturi effect. At 50-
Real flow calibration is not required within the 1200 caliber scale, because of its high precision, small pressure loss and not easy to wear, it is often used as an external surface of transaction settlement flow for accurate measurement of steam, natural gas and petrochemical media.
Its planning and production are planned and produced according to the national standard GB/T2624-93 or ISO5167, and are verified according to the national standard JJG640-94.
It is used to measure the flow rate of single-phase stable fluid in closed pipelines, and is often used to measure the flow rate of air, natural gas, gas, water and other fluids.
In the standard saving equipment, the upper and lower straight pipe sections it requires are short, the lasting pressure loss is small, the function is stable, and the protection is convenient.
Because of its accurate accounting and low energy consumption, it has been widely used in petroleum, chemical industry, electric power and metallurgy.