Application Of Micro-displacement Method In Gas Holdup Measurement And Flow Regime Discrimination In A Bubble Column

Direct coal liquefication technology obtains more and more attention in our country as the energy situation becoming more and more serious. The basic research has been completed on the whole, and researchers have mastered certain intellectual property technology. But the technical enlargement research is at the initial stage actually. The direct coal liquefication process is carried on under the severe environments such as high temperature and high pressure, etc, so the developing of effective parameters test method become the essential key to promote liquefication enlargement research.In order to solve the problem, all kinds of chemical equipment supporting frames are summarized. Tensile deformation, compressive deformation and flexural deformation under static load and dynamic load are discussed, respectively. Based on the linear relationship of load-deformation in elastic range, a micro-displacement method is proposed to test fluid dynamic parameters in reactors by measuring supporting frame's microdeformation. This method can test the mass and flow load interrelated parameters, such as gas holdup and flow regime.1:1 cold model experiment setting was established by referring to the 0.1t/d experimental device of NEDOL coal liquefaction process. The finite element analysis and experimental calibration results validate the feasibility of micro-displacement method. The gas holdup datas of bubble column were obtained under different superficial gas velocity, different liquid viscosity and different surface tension for the nitrogen-water system, and the results were verified by using shutdown method. The dynamic displacement signal of bubble column was collected in different flow regime, and the data was performed by using statistic analysis, fourier analysis, wavelet analysis and multi-scale analysis. These analyses show good agreement in the transformation scale of small bubble and big bubble. The experimental study supports the assumption that micro-displacement signal can be regarded as one effective judging criterion of flow regime.These experimental results show that the novel micro-displacement method has many advantages such as high precision, low testing cost, convenient operation and maintenance, and so on. The measurement process has instructive function for solving the testing problem of multiphase flow, and can not be affected by reaction condition such as high temperature, high pressure and high causticity for it measuring external parameter, instead of internal parameter.