Study On Inner Gas-liquid Coupling And Pressure Fluctuation Characteristic Of Self-swash Dust Separator

Dust separator is a kind of device which is widely used in process industries to separate and collect dust from airflow containing dust, and it is the core equipment of dust control project. With more and more demanding requirements on environment of people, dust separator applied in industrial production is drawing more and more attention by people. As one kind of many dust separators, Self-swash dust separator has the advantage in simple structure, low cost, convenient operation and maintenance, and it is suitable for high temperature, flammable and explosive environment. So it has great significance to carry out theoretical and experimental research to improve the performance of self-swash dust separator.This paper relies on the project of National Natural Science Fund—droplet formation mechanism and micro regulation of self-swash dust separator—to analyze and research the coupling process of gas and dust removal liquid in the working process of self-swash dust separator, using a model of self-swash dust separator as study object and by theoretical derivation, experimental study and verification experiment.Through the theoretical analysis, the working process of self-swash dust separator is divided into two phases as inertial dedusting and droplet dedusting according to different mechanism. In the stage of inertial dust removal, it depends on the centrifugal force at the arc flow channel to dedust, and this stage is only for the size of over 100μm with the dust removal efficiency of 90%, and the dust which smaller than 100μm mainly depends on the droplet dedusting. These parameters—the ratio of liquid to gas, gas-liquid relative velocity, size of droplet and so on—are the main influence factors to dust removal efficiency of droplet dedusting, but the premise of these factors is the fully coupled gas-liquid contact.Through the experimental study, it suggests that properly installed dehydrator is the essential condition to ensure the re-impact of airflow to liquid curtain and promote the contact of gas stream and dust removal liquid. In the experiment, five kind of typical gas-liquid model were observed. They are weak fluctuation model, static liquid level difference model, air-hammer flow model, shear liquid curtain model and entrainment of air bubble model, which occur at the condition of different initial level h0 and different gas flow, and they represents the working condition of self-swash dust separator.In the working process of self-swash dust separator, throttling velocity Uj shows different variety law with the variation of Q under the condition of full throttling, strong throttling and weak throttling. For the flexible throttling effect of throttling plate, according to different degree of gas-liquid coupling, inner pressure of self-swash dust separator shows obviously distinguishing fluctuation characteristic including low mean and high frequency pulse area, double wave superposition area, and high mean and high frequency pulse area. And these fluctuation characteristic can qualitatively describe the characteristic of the gas-liquid coupling state.The initial liquid level h0 and gas flow Q determine the inner gas-liquid coupling state. With higher initial liquid level h0, it is more easy to form throttle level difference and conducive to the inertial dedusting. And higher gas flow Q will lead to more intense gas-liquid coupling. But it is not the highest initial liquid level and maximum gas flow for the optimal dedusting liquid curtain. The experimental results suggest that the initial level of 0~20mm height is appropriate, and the optimal air flow varies depending on the initial level. And the dust removal efficiency of self-swash dust separator increase with the increase of initial liquid level or gas flow.