An external radial magnetic field and built-in stainless steel balls formed a magnetic suspended layer (MSL), as observed in this study. Under the condition of crossflow inflow, the flocculating agent and coagulant aids form a flocculated particles suspension layer (FPSL). Thus a double suspended fluidized bed reactor was constructed to treat bathing wastewater. Using a Particle image velocimetry device to detect flow patterns, analyze the flocculation conditions. The results showed that under the condition of crossflow inflow, at the same time,the flooding water was 0.023–2.101 m3/h, and the dosage of poly aluminum chloride (PAC) and Polyacrylic Amide (PAM) was 90 mg/L and 1.5 mg/L, respectively, removed rates of Turbidity, Chemical Oxygen Demand (CODCr) and linear alkylbenzene sulphonates (LAS) reached more than 99, 90,and 80%. Filtration, grid flocculation and particle interception were functions of the MSL. Meanwhile, the crossflow input created additional vortexes, increasing the likelihood of flocculation particle collision, improving the flocculation condition, and cleaning the MSL. The reactor aids in the development of the initial flocculated particles suspension layer, flocculation strengthening, chemical dosage reducting, effluent qualities improvement, and effluent stability maintenance.

The paper presents an noval N-substitution pressure fixed point iteration method under steady-state condition for hydrodynamic calculation of indoor fire hydrant system in building.The modeling bases on introduction the functions of sign,absolute value and maximum value improve intelligence and eliminate illegal computing, application of the Taylor series expansion and linear optimization.And then,according to the principle of numerical calculation,the correction pressure fixed point iteration model was obtained by a natural number N replacing the denominator. In a case, the method combining with MS Excel is applied to hydraulic calculation of building hydrant pipe network system. The results shown that, when N is 10000, only one of the 22 calculated points oscillated around the true value in the early calculation, and converged to the true value in the later calculation.But the calculation errors of the system and the pressure control points converged from beginning to end. The calculation error of the system is twice that of the pressure control point when the calculation errors of all the nodes converge. In the future, N replaces the denominator, which can also provide a reference for the hydrodynamic iterative calculation methods under steady-state condition, such as flow, equivalent flow (building domestic water supply network), temperature (building hot water supply network).

Building water supply and drainage is one of the important courses of construction engineering technology. It is a construction project that must be considered in modern building construction. It is directly related to people’s daily production and life. It has a very distinct practicality. Its teaching content is also accompanied by materials and Building technology upgrades and continuous improvement. This article discusses the problems existing in the teaching of building water supply and drainage, and proposes corresponding teaching reform measures for the problems found, in the hope that the teaching of building water supply and drainage can achieve better teaching effects.