Wet-type gas flowmeter with high measurement accuracy, metering drum swing mechanism and metering indication mechanism

Abstract

The invention discloses a wet-type gas flowmeter with high measurement accuracy, a metering drum swing mechanism and a metering indication mechanism. The wet-type gas flowmeter is composed of a shell sealing supporting assembly, the metering drum swing mechanism and the metering indicating value indication mechanism. The shell sealing supporting assembly is composed of a sealing shell, an air inlet connector, an output air pipe, an air outlet connector and a supporting seat, the metering drum rotating mechanism is composed of a metering drum, a sleeve, an inner magnetic disc, a shaft, a ball bearing and a universal ball head, and the metering indicating value indication mechanism is composed of a pointer, a mandrel, a bearing, a bearing seat, a mounting support and an outer magnetic disc. According to the invention, the measured gas pushes the metering drum mounted in the shell to rotate, and then the metering value is transmitted to the metering indicating value indication mechanism outside the shell through magnetic coupling; meanwhile, the manufacturability of the whole machine structure is improved, and interchangeability of all large components of the flow meter is achieved. The rotating stability of the metering drum is improved, and the influence of liquid level fluctuation on the metering precision is reduced.

Description

technical field [0001] The patent of the invention relates to a metering instrument for gas volume measurement, in particular to a high-accuracy wet-type gas flowmeter, a metering drum rotation mechanism, and a metering indicating mechanism. [0002] technical background [0003] The wet gas flowmeter is a volumetric gas flowmeter that relies on the sealing liquid to completely isolate the gas inlet and outlet of the metering drum. It has the characteristics of no leakage and stable measurement. High-accuracy wet gas flowmeters are required to have a measurement expansion uncertainty of 0.5%, 0.2%, and are often used as standard devices. [0004] The wet gas flowmeter is mainly composed of a rotatable drum that is divided into 3 to 5 metering gas chambers by spiral blades. The drum is supported in a sealed liquid with a certain liquid level and rotated by the pressure difference between the incoming and outgoing gases. , the metering chamber leaves the liquid surface to infl...

AI Technical Summary

Problems solved by technology

[0005] Due to the unreasonable structural design of the wet gas flowmeter in the industry, when the gas flow rate tested by the wet gas flowmeter increases, the pressure difference between the metering chamber and the outside becomes larger, and the liquid level difference of the sealing liquid increases accordingly, which increases the volume of the metering chamber. , the indication error has obvious deviation, so that the indication error in the actual test process is generally within a large range of ±1% to ±1.5%.

[0006] In addition, when the same flow rate is measured continuously for several times under the same environment and working conditions, the measurement error is a random error, and the random error is mainly affected by the stability of the metering drum rotation process. Therefore, in the measurement process , to improve measurement repeatability, the stability of the support bearing rotation of the metering drum must be well guaranteed

However, due to the requirement for the portability of the flowmeter, the welded and assembled components of the shell are manufactured by welding thin-walled metal materials. During the welding process, the position accuracy of the support bearing mounting hole used to support the metering drum mandrel is difficult to guarantee. As a result, the smoothness of the metering drum rotation process is affected

[0007] In the existing wet gas flowmeter, the shaft supporting the metering drum and the installation hole of the supporting bearing are sealed with an oil seal. However, the oil seal is a vulnerable part, which is prone to wear and failure, and thus there is a hidden danger of sealing fluid leakage; At the same time, when the oil seal wears and fails, the friction will increase, which will affect the rotation stability of the metering drum, resulting in poor metering accuracy

[0008] In summary, the accuracy of existing wet gas flowmeters is easily affected during actual use. Therefore, a high-accuracy wet gas flowmeter with good repeatability is urgently needed

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