English Name: flowmeter flow meter definition: indicator of flow and (or) the total amount of fluid within the selected time interval meter.
The development of flow measurement can be traced back to ancient water conservancy projects and urban water supply system. Ancient Rome Kaiser era has been used to measure the water consumption of residents of the orifice plate. The flow of the Nile River in the ancient Egypt in about 1000 B. c.. The water level of our country's famous Dujiangyan water conservancy engineering application baopingkou observation quantity etc.. Flow meter is also divided into rotor flowmeter, throttle flowmeter, slit flowmeter, volumetric flowmeter, electromagnetic flowmeter, ultrasonic flowmeter and weirs.
In seventeenth Century Tori Lee demolition lay the theoretical foundation of differential pressure flowmeter, it is the milepost of flow measurement. Since then, the prototype of the 18th and 19th century flow measurement of many types of instruments began to form, such as weir, tracer method, the pitot tube, venturi tube, volume, turbine and target type flowmeter. Twentieth Century due to the process of industry, energy measurement, urban public utilities on the demand for traffic measurement, the rapid development of the instrument, the rapid development of microelectronics technology and computer technology, the rapid development of a great impetus to the development of new instruments, new type flow meter has sprung up. So far, it has been said to have hundreds of meters to the market, many difficult problems to be solved in the field is expected to be resolved.
In our country, the work of the modern traffic measurement technology is relatively late, and the required flow meters are imported from abroad.
Flow measurement is the scientific research quality, the law of mutual change of quality and quantity is the basic law of things development, so the measurement object is not limited to traditional liquid pipelines where Master quantitative flow measurement. Flow and pressure and temperature are three main detection parameters. For a certain fluid, as long as these three parameters can be calculated with the energy, the three parameters must be detected in the measurement of energy conversion. Energy conversion is the basis of all production processes and scientific experiments, and thus the flow and pressure, temperature, as the most widely used instrument.
Application domain of flow meter:
Flow measurement technology and instrumentation applications generally have the following areas.
Industrial production process
Flow meter is one of process automation instrumentation and equipment in large instrument. It is widely used in metallurgy, electric power, coal, chemical industry, petroleum, transportation, construction, textile, food, medicine, agriculture, environmental protection and people's daily life in various fields of the national economy, is the development of industry and agriculture production, save energy, improve product quality, enhance the economic efficiency and the management level is an important tool in the national economy occupies an important position. In the process of automatic instruments and devices, the flow meter has two functions: as a process automation control system for the detection and measurement of the total amount of material.
Two energy measurement
Energy is divided into primary energy (coal, oil, coal, gas, oil and natural gas), two energy (electricity, coke, artificial gas, refined oil, liquefied petroleum gas, steam) and can work (compressed air, oxygen, nitrogen, hydrogen, water), etc.. Energy measurement is an important means of scientific management of energy, energy saving and reducing consumption, improve economic efficiency. Flow meter is an important part of energy meter, water, artificial gas, natural gas, steam and oil are used in these common energy meter, which is an indispensable tool for energy management and economic accounting.
Three environmental protection project
The discharge of waste gas, waste water, sewage and other serious pollution of air and water resources, a serious threat to human living environment. State to the sustainable development as a national policy, environmental protection will be the biggest issue in twenty-first Century. Air and water pollution to be controlled, must strengthen the management, and the management of the foundation is the quantitative control of pollution.
China is a country with coal as the main energy, and there are millions of chimneys in the country. Flue gas emission control is an important item of radical pollution, each chimney must install flue gas analysis instrument and meter, composed of even the casket discharge monitoring system. Flue gas flow water quantity is very difficult, the difficulty of chimney size and irregular shape, gas group changes uncertain. Velocity range high, dirt, dust, corrosion, high temperature, no straight pipe.
Four transportation
There are five ways: Railway highway, air, water, and pipeline transportation. Although the pipeline transport has long been, but the application is not widespread. With the outstanding problems of environmental protection, the characteristics of the pipeline transportation, people pay more attention to it. Pipeline transportation must be equipped with flow meter, which is the control, distribution and scheduling of the eyes, is also a necessary tool for security monitoring and economic accounting.
Five biological technology
Twenty-first Century will usher in the life sciences in the 21st century, the industry will be characterized by biotechnology will get rapid development. Biological technology to monitor the measurement of many substances, such as blood, urine, etc.. Instrument development is very difficult, a wide variety of.
Six scientific experiments
Scientific experiments need not only a large number of flow meter, and variety is extremely complicated. According to statistics, a large part of the more than 100 kinds of large part of scientific research, they are not mass production, in the market for sale, many research institutions and large enterprises have set up a special team to develop special flow meter.
Type of flow meter
Instrumentation for measuring the flow of fluid flow in a pipe (the volume of fluid passing through the unit time).
Flow measurement methods and instruments of a wide variety of classification method is also a lot of. Up to now, there are more than 60 types of flow meters for industrial use. The reason for this is that it has not been found in any fluid, any range, any flow state, and any use of the condition.
These 60 kinds of flow meters, each product has its specific applicability, also have its limitations. By dividing the measuring object is closed pipe and open channel; according to the purpose of measurement can be divided into the total measurement and flow measurement, the instrument are respectively called total scale and flowmeter.
Measuring the flow over a period of time by the total meter is the total amount of the total flow over a short period of time. Therefore, the strict sense of the flow meter and the total table has no practical significance.
According to the principle of measurement, the principle of mechanics, heat, acoustic principle, electrical principle, optical principle, atomic physics, etc..
According to the classification method is currently the most popular, the most widely, which is divided into: volumetric flowmeter, differential pressure type flowmeter, floater flowmeter, turbine flowmeter, electromagnetic flowmeter, fluid oscillatory flowmeter vortex flowmeter, mass flowmeter and insert type flowmeter, probe type flow meter, were described principle, characteristics, application situation at home and abroad development of various flowmeters.
According to the principle of the flow meter, there are volume type flowmeter, leaf type flowmeter, differential pressure type flowmeter, variable area type flowmeter, momentum flowmeter, impulse type flowmeter, electromagnetic flowmeter, ultrasonic flowmeter, mass flow meter, fluid oscillatory flowmeter.
