Chương này bàn về các hoạt động đơn vị đo dòng chảy và lưu lượng và equalizations chất lượng. Mét dòng chảy được thảo luận bao gồm weirs hình chữ nhật, weirs hình tam giác, weirs hình thang, venturi mét, và một trong các flumes quan trọng dòng chảy, máng Parshall. | Part II Unit Operations of Water and Wastewater Treatment Part II covers the unit operations of flow measurements and flow and quality equalizations pumping screening sedimentation and flotation mixing and flocculation filtration aeration and stripping and membrane processes and carbon adsorption. These unit operations are an integral part in the physical treatment of water and wastewater. 2003 by A. P. Sincere and G. A. Sincere 3 Flow Measurements and Flow and Quality Equalizations This chapter discusses the unit operations of flow measurements and flow and quality equalizations. Flow meters discussed include rectangular weirs triangular weirs trapezoidal weirs venturi meters and one of the critical-flow flumes the Parshall flume. Miscellaneous flow meters including the magnetic flow meter turbine flow meter nutating disk meter and the rotameter are also discussed. These meters are classified as miscellaneous because they will not be treated analytically but simply described. In addition liquid level recorders are also briefly discussed. FLOW METERS Flow meters are devices that are used to measure the rate of flow of fluids. In wastewater treatment the choice of flow meters is especially critical because of the solids that are transported by the wastewater flow. In all cases the possibility of solids being lodged onto the metering device should be investigated. If the flow has enough energy to be self-cleaning or if solids have been removed from the wastewater weirs may be employed. Venturi meters and critical-flow flumes are well suited for measurement of flows that contain floating solids in them. All these flowmeasuring devices are suitable for measuring flows of water. Flow meters fall into the broad category of meters for open-channel flow measurements and meters for closed-channel flow measurements. Venturi meters are closed-channel flow measuring devices whereas weirs and critical-flow flumes are open-channel flow measuring devices. Rectangular .
