Method and device for detecting mist entrainment in multiphase flow equipment

Abstract

The invention discloses a method for detecting mist entrainment in multiphase flow equipment, comprising the steps of: 1) receiving vibration signals or sound wave signals in multiphase flow equipment; 2) selecting the total energy and characteristics of the vibration signals or sound wave signals The energy of the frequency band or the energy fraction of the characteristic frequency band is used as the characteristic parameter; 3) Substituting the characteristic parameter into the prediction model between the pre-established characteristic parameter and the mist entrainment amount, and calculating the mist entrainment amount in the multiphase flow equipment. The method adopts a nonlinear method to process the signal, can obtain the characteristic parameters of the signal more accurately and effectively, and obtain the real-time mist entrainment amount; the method has sensitive response, small measurement error and wide application. The invention also discloses a detection device, which includes a signal receiving device, a signal amplifying device, a signal collecting device, a signal processing device, an output display device and a control device. The device is non-intrusive for ease of use and does not interfere with fluid motion or chemical reactions; no emission source is required.

Description

technical field [0001] The invention relates to the field of chemical dynamic monitoring methods and devices, in particular to a dynamic detection method and device for mist entrainment in multiphase flow equipment. Background technique [0002] There are many multiphase flow equipment in the chemical process, such as plate tower, gas-liquid two-phase or gas-liquid-solid three-phase stirred tank, bubbling bed, etc., when gas-liquid mixing is often accompanied by mist entrainment. Fog entrainment refers to the phenomenon that when the gas passes through the liquid layer from bottom to top, the mist generated by the turbulence of the liquid surface is carried away by the air flow and enters the upper device or pipeline. For the three-phase system, there will also be a small amount of solids entrained by the gas along with the mist droplets. [0003] Fog entrainment has a detrimental effect on chemical processes. In the polymerization reaction device, a large amount of mist e...

AI Technical Summary

Problems solved by technology

[0013] 1) The research object is mainly the plate distillation column, and there are few studies on other equipment, such as aeration stirring tank, bubble column, etc.

[0014] 2) The research focus is mainly on the analysis and correlation of the causes of mist entrainment and the main influencing factors, and there are few studies on the detection methods of mist entrainment

[0015] 3) The research system is mainly the gas-liquid mass transfer system, and there are few studies on the phenomenon that solids are entrained together in the gas-liquid-solid three-phase system

[0016] 4) The collection method is often used to measure the amount of mist entrainment, which has large errors and is inconvenient to operate, and cannot be applied to industrial devices

[0017] 5) There are many reports about demisters. The analysis of demister performance is mainly carried out in the laboratory. Due to the limitation of detection methods in industry, it is difficult to obtain direct results of demister effect.

However, wavelet analysis is based on Fourier analysis, so it has the disadvantage of Fourier analysis and can only give a physical interpretation of the linear case

Another problem with wavelet analysis is that it is not adaptive, once the basic wavelet is selected, it must be used to analyze all the data to be analyzed

Images