Soap film flowmeter capable of automatically wetting soap tube and adjusting liquid level speed and testing method

Abstract

The invention provides a soap film flowmeter capable of automatically wetting a soap tube and adjusting the liquid level speed and a testing method, and belongs to the technical field of soap film flowmeters. The flow meter comprises a soap film speed measuring module, a liquid soap buffering module, a liquid level sensing and measuring module and a gas circuit integrated control module, the soap film speed measuring module is installed on the left side of the upper portion of the liquid soap buffering module, the gas circuit integrated control module is installed on the right side of the upper portion of the liquid soap buffering module, and the liquid level sensing and measuring module is installed on one side of the bottom of the liquid soap buffering module. According to the soap film flowmeter, the purpose that the liquid level in a soap tube of the soap film speed measuring module rises and falls rapidly is achieved by controlling the pressure intensity of gas in the gas circuit integration module and through temporary storage buffering of the liquid soap buffering module. The soap film flowmeter can automatically complete the functions of soap tube wetting, liquid level monitoring, liquid level lifting speed control and the like.

Description

technical field [0001] The invention relates to the technical field of soap film flowmeters, in particular to a soap film flowmeter and a testing method for automatically wetting a soap tube and adjusting the liquid surface speed. Background technique [0002] The soap film flowmeter calculates the gas flow by measuring the time difference between the soap film passing through two photoelectric sensors in turn, and is mainly suitable for the measurement and verification of small gas flow. The traditional soap film flowmeter has deficiencies in wetting, film production, accuracy, etc. The main manifestations are as follows: [0003] (1) Wetting problem [0004] The soap film flowmeter needs to be wetted before use. The soap liquid evenly attached to the inner wall of the soap tube forms a liquid film with a lubricating effect, which reduces the rising resistance of the soap film. Remove the soap tube and re-wet it, which affects the measurement process; the prior art disclo...

AI Technical Summary

Problems solved by technology

[0004] The soap film flowmeter needs to be wetted before use. The soap liquid evenly attached to the inner wall of the soap tube forms a lubricating liquid film, which reduces the rising resistance of the soap film. As the measurement time prolongs, the liquid film becomes thinner under the action of gravity and evaporation. Remove the soap tube and re-wet it, which affects the measurement process; an electronic soap film flowmeter and a test method for automatically and continuously wetting the soap tube are disclosed in the prior art. The automatic wetting device blocks the space at the upper port of the soap tube, the gas flow is not smooth, the resistance increases, and the soap film rises slowly, resulting in a small measurement result; the path of the wet soap liquid flowing down the inner wall of the soap tube is uncertain and easy to form Trench flow impacts the rising soap film, and wets to form a thin and uneven liquid film that affects the surface tension of the soap film, resulting in soap film rupture; when the downflowing soap liquid reaches the bottom, the liquid surface oscillates due to the impact , a large number of small bubbles accumulate on the liquid surface and are difficult to eliminate. When the liquid level in the soap tube rises again to form a film, a soap film with agglomerated bubbles is formed, the resistance increases, and the measured gas volume is relatively small

The above factors will affect the accuracy of the measurement process and experimental data

[0005] (2) Film production problem

[0006] When the liquid surface of the soap liquid is in contact with the upper apex of the gas inlet of the soap tube to be tested, a single soap film will be produced under the action of the airflow, but in the actual measurement process, the phenomenon of continuous and non-film formation often occurs. The soap film blocks the flow of gas in the soap tube, increases the pressure in the tube, and forms resistance to the soap film below. The gas flow value is too small, which affects the measurement accuracy

The prior art discloses an electronic soap film flowmeter that automatically produces foam. The electromagnet drives the weight to dip into the liquid storage tank to raise the liquid level in the soap tube to generate a soap film, but the soap can be splashed from the gap between the weight and the tank wall. As a result, the liquid level difference between the liquid storage tank and the soap tube decreases, causing the liquid level in the soap tube to drop slowly when the weight is lifted, and presents wave vibrations under the disturbance of the air flow to be measured, and contacts with the upper apex of the gas inlet to be tested many times, resulting in Multiple soap films; the repeated impact of the heavy hammer causes the amount of soap liquid in the liquid storage tank to decrease, and the liquid level difference generated in the subsequent measurement cannot cause the liquid level in the soap tube to rise beyond the upper apex of the gas inlet to be tested, and the soap film cannot be produced; Airbag soap film flowmeter (Automation Instruments, 2019, 40(10): 70-75.) Inflates and deflates the airbag to cause a rapid change in the pressure in the soap liquid storage tank, and controls the rise and fall of the liquid level in the soap pipe, but due to the airbag itself Characteristics, the pressure change caused by inflation and deflation is first acute and then slow. The liquid level in the soap tube rises (decreases) rapidly and then rises (decreases) slowly. The liquid level is uncontrollable and cannot ensure that the liquid level is at the inlet of the gas to be tested. The upper apex drops rapidly; and the material of the airbag is mostly rubber. After repeated flow measurements, the elasticity of the rubber weakens, and the airbag becomes loose. Membrane phenomenon is inevitable

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