Study On Degas Treatment Of Feedwater By Hollow Fiber Membrane

This essay mainly introduces the principle of the membrane contactor, the structure of equipment and the way to install degassing system efficiently. Then the flow chart of degassing system and the drawing of configuration of this system are shown in the forth part.Through the pilot scale experiment of degassing, the relations between the removal efficiency and correlative parameters are inspected. In this analysis, the significant point is focused on the effect of temperature, current velocity, mass-transfer coefficient, volume of gas-taken, surface area of membrane and vacuum degree on removal efficiency.The experiment draws conclusions to be as follows, i . Lower the pressure of gas phase is, bigger the concentration gradient which gas film forms, favoring the mass-transfer, thus it enhances the removal efficiency, ii. By the look of liquid phase, the density of the gas solubility in the liquid phase is reduced correspondingly because of temperature rising. Secondly, the trace that the rising of temperature will cause the expansion of micropores to help the gas molecule to overflow, iii. Thus the degasificate efficiency along with the current velocity increase gradually reduces. Because the increase in current velocity causes the cut of resident time of liquid phase in the membrane, leading to the reduction of contact duration between the liquid phase and the vacuum side, iv. On the condition that hollow fiber-membrane is not transformed, the increase of pumps can improve the degasification. v. Connecting membranes in parallel just plays the function of the enlarging surface area of membrane which is suitable for the situation used in the large flow; when membranes connect in series, the number of getting rid of efficiency presents geometric progression to increase which is suitable for the complexation used in the small flow to deal with.Then, choose the daily variable to set up the mathematical model of this project and imitate the mathematical model of this project with the mathematical model of the theory to compare them again. This is exactly an innovation of this thesis.Last but not least, some problems and difficulties about this pilot scale experiment of degassing are put forward, at the same time the feasible solutions are provided correspondingly.