| Technological and hydraulic designs are the two aspects in the water treatment engineering. Technological design researches are performed far and wide both in domestic and abroad. The information on hydraulic computation is very scarce after it had been consulted.Background and significant of the thesis are narrated first. Some factors that influence the efficiency of Upflow Anaerobic Sludge Blanket (UASB) are pointed. Unification of the water distributor and the effect of separation of three-phase separator are more important. Considering the hydraulics, the thesis aims to improve the water distributor and uncover the flow character in UASB through analyzing the whole flow zone. It also can provide foundation for reasonable design. Development situation and new forms of UASB are summarized.There are two main parts in the paper. The one is the hydraulic computation of water distributor in UASB. Linear algebra equations are founded by finite element method and Seidel iteration method is used for computation. In order to reach the unification, the fluxes of each hole are assumed to be same so as to calculate the water head of each orifice. Then the diameter of each pipe segment is computed by orifice outflow formula According to the computational method of network, diameters of pipes are determined with finite element method when the fluxes of wastewater is known, as concerning the local resistance, in order to achieve uniformity in the first part. The water distributor on the bottom of UASB is often jammed, when operating in practice. So that uniformity of water distribution is destroyed. In order to improve the efficiency of water treatment, the lack of this construction is put forward in the paper in the light of the characters of the water distributor in engineering. Local resistance should be concerned at the same time, according to the principle of hydraulic computation of the gridiron in the municipal engineering. Hydraulic computation is performed by finite element method. Design references and more reasonable structure dimensions about water distributors are provided for water treatment engineering.The second part is the numerical computation of flow zone in UASB related to this type of water distributor. This part is on the basis of the first one. Some kinds of numerical computation methods are recommended systematically including finite volume method, finite analysis method, finite element method and self-fit mesh method. The history of finite differential method and application in environmental engineer are represented. The initial conditions that include both steady flow and unsteady flow are expounded. The ways of linear equation groups are referred. Boundary treatment fundamentals and measures are illustrated. Especially, vortex boundary condition on solid wall is emphasized. Plotting mesh is also a keystone in computational fluid dynamics. Method of mesh plotting of UASB is presented after analyzing some ways. Foursquare mesh can meet with precision. Cylindrical coordinates are selected according to the unique character. The basic equations become more complicated, but the problem can be simplified by reducing dimensions from three to two. So it can lighten the load. Then, stream function and vortex are adopted as the basic variables. Thus, stream function and vortex equations can be achieved. At last, the equations that disperse with finite differential method can be solved by super relaxation iteration.Vortex on the solid walls is the most difficulties. The nods on walls Taylor outspread, formula that is used to calculate vortex on wall can be deduced.The basic math model is as followsThe two formulas are dispersed by center differential format.The formulas of vortex on wall are follows(r direction)(z direction)Solution process can be divided into three steps. The first step is to calculate stream function with vortex and stream function that is gained from last time iteration. The second step is to compute vortex from last time iteration and stream function fr...
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