Industry new

Vortex flowmeter development overview description

In the natural world, there are many fluid vibration scenes. For example, the flag is recruited in the wind; the sound of the overhead aerial wires retracted in the wind; the small stream makes the water grass, the seedlings, and the small trunks in the water frequently swing, etc., which are detailed expressions of the fluid vibration scene. In the hydrodynamic oscillation scene, there is a correspondence between the fluid vibration frequency and the flow velocity. The instrument that uses this principle to measure flow is important to include a Vortex Shedding Flowmeter, often referred to as a vortex flowmeter; a Vortex Precessing Flowmeter, often referred to as a vortex flowmeter; a fluid flowmeter (Fluidic Flowmeter) ).
Since the beginning of the mid-1960s, scientists from the United States, Europe, and Japan have invested in fluid vibration flowmeters in different ways. By the end of the 1960s and early 1970s, the above three flowmeters had emerged. Due to the causes of manufacturing, operation and promotion, the three flowmeters have different deployment conditions. The characteristics of the vortex flowmeter are fully contrasted and received by the user earlier and expanded most agilely. The other two instruments are definitely slower to expand, but they have gradually been promoted in recent years.
In ancient times, people paid attention to the fact that the wind can make the tensioned strings retract different sounds. In the middle of the night, the self-sounding piano hanging on the wall of the bed was blown back by the night wind, and the guest was awakened from the dream. In the mid-16th century, the famous painter and scientist Da Vinci described the vortex columns emerging in front of the bluff body in his works.
The first person in the world to study the vortex scene was the Hungarian physicist Strouhal. In 1878, in his experiment, he invented: Under the action of the wind, the tone of a thin string sound is inversely proportional to the wind speed and inversely proportional to the diameter of the string.
In 1879, Rod Laret (playing rd.R five deight) was invented: when the vortex caused fluid vibration, the direction of vibration was perpendicular to the direction of motion; he also observed that the natural tone of the strings and the tone of the wind When they match, the sound will suddenly increase.
In 1908, Bernard (Ben Nai) pointed out that the periodicity of the wake in front of the cylinder is related to the formation and arrangement of the vortex.
In 1912, the German physicist Von.Kallnan conducted a small number of experimental inspections, studied the stability of the vortex street, and announced a well-known paper on the stability conditions of the vortex in the infinite average flow field. . Mathematically confirmed the stability condition of the vortex street caused by the upstream of the cylinder. This argument by Kaman laid the foundation for the development and application of the vortex flowmeter.
However, the important goal of people studying the vortex scene in the late stage is to prevent disasters. With the development of the industry, especially the development of the aviation industry, the vortex street was invented to cause damage to consumption and construction equipment, such as high-rise buildings, bridges, towers, port equipment, ship masts, cables, drilling platform supports, etc. The breeze is destroyed; the boiler tube, the manifold in the heat exchanger, and the damage or breakage of the temperature measuring casing in the pipeline are all related to the vortex street. Therefore, in a long time, scholars are inspecting and delving into the law of vortex street, exploring the causes of the violent disruption of vortex, and finding ways to avoid such damage. In the mid-20th century, some scholars claimed that the compromise between human and vortex damage has been going on for nearly half a century.
There are always two sides of things. When some people are studying the role of avoiding vortex destruction, others are discussing how to use vortex scenes and principles to do useful tasks. Using Kaman vortex to measure the fluid flow rate. It is one of them. This kind of imagination was first seen in the US patent of 1935. In the 1950s, American scientist Roshko proposed the ability to measure wind speed using the Karman vortex street and conducted experiments. In 1960, on the Japanese Shibo ship, an experiment was conducted to measure the ship's speed using the Karman vortex principle.
All the above experimental research tasks are carried out under the condition of two-dimensional average flow field with infinity. In the three-dimensional flow field, the vortex measurement flow is drilled. It will be postponed until the mid-1960s. In this era, scientists from countries such as Japan, the United States, and the former Soviet Union have successively launched research and development tasks for vortex flowmeters.
In 1967, Japanese scholars Tsuchiya Hiroyuki and Yamazaki Hiroshi studied the vortex principle to measure the flow of a circular tube. A cylinder was placed vertically in the circular tube, and a metal flag that was rotatable around a fixed axis was placed upstream of the cylinder. When the fluid is active, the action of the vortex street causes the flag to swing to the left and right, thereby detecting the vortex signal and performing a flow measurement experiment.
In 1969, Yamazaki Hiroshi and others studied the vortex flowmeter for the victory hot wire detection method. The vortex episode (hereinafter referred to as the episode) is a cylinder. This effect was finally led by the Yokogawa Manufacturing Corporation to introduce a commercial vortex flowmeter. At the same time, ‘East-ech Company of the United States developed the vortex flowmeter for the successful thermistor detection method. This flowmeter adopts a triangular column and was originally introduced by OVAL Corporation of Japan.
These two instruments have become the forerunners of vortex flowmeters and have been used in steel, petroleum, chemical and other industries. Its characteristics have attracted attention from all quarters, and it has also predicted to the world the dark future of vortex flowmeters.
In the 1970s, the vortex flowmeter entered the era of rapid development, and various new detection methods and new products came out, making people dazzling. In the 1970s, the new products of vortex flowmeters introduced by national instrument companies were
(United States) Westing House (Westing House) uses ultrasonic testing techniques to introduce ultrasonic vortex flowmeters;
(Day) Beichen Motor Factory uses strain detection techniques to develop a successful strain vortex flowmeter;
(US) Easttech Corporation (Eastech) introduced the second type of vortex flowmeter, which is a vibrating body vortex flowmeter using magnetoelectric detection technology;
(English) Kent Corporation used capacitor detection techniques and rectangular body to provide users with capacitive vortex flowmeters;
(US) Ficher & Porter uses strain detection techniques to contribute enhanced strain vortex flowmeters to users;
(US) Foxboro Company adopts piezoelectric detection technology and uses T-shaped episodes to bring vortex flowmeters with piezoelectric elements and diaphragms as detection elements to the market.
(Day) Yokogawa has been developing for nearly 10 years, using piezoelectric detection techniques and ladder-type episodes, following the hot-wire vortex flowmeter, launched the company's second vortex flowmeter product, a stress-type vortex street. Flow meter.
In the 1980s, the development of the vortex flowmeter was as strong as ever, the new products were inherited, and the old products have been improved and improved.
(US) Fishercont Gong 1 Island Company developed a double-onset stress-type vortex flowmeter;
(German) E+H Company and (English) Kent Company used piezoelectric detection technology to break up the vortex flowmeter of the rear detection type of the detection component and the detection component.
(US) Rcher 诬 ner company opened the double attack body and double detection component stress vortex flowmeter, and first provided the customer with dry calibration technology indicators in the device application book;
(Day) Tokyo Metropolitan Equipment Co., Ltd. developed the Victory Photovoltaic Vortex Flowmeter; by the early 1980s, the United States, Europe and Japan’s Hangzhou moving company prices had broken up and about 10 companies to consume various vortex flowmeter products. According to the introduction of relevant materials, 1987. World vortex
The output of street flowmeters is close to 40,000 units.
An important milestone in the development of vortex flowmeters is that the standardization of products has attracted the attention of all countries. The prosperous countries such as the United States, Japan, and Germany have successively formulated and announced their own vortex flowmeter product standards. In 1987, the United States upgraded the machinery industry standard to the national standard AS plus ANsl MFC ‘M-1987; in 1989 Japan published the industrial standard JIS 2 8766-1989; Germany also announced the product standard for vortex flowmeter. After the standards were announced in various important countries, the domestic standardization organization (Qiao 0) set out to develop the domestic standard for vortex flowmeters, and in 1993 it was announced in the draft standard (Qiao 0/CD12764). The development, manufacture and application of these marked vortex flowmeters have entered the era of standardization.

PREVIOUS：Direct turbine mass flow meter introductionNEXT：How to complete the heat metering introductio