ABSTRACT
The knowledge of mass flow rates is necessary in combustion fuel control, in reactor recipe formulations, and in many other applications, from mining and dredging to food, pulp and paper, pharmaceuticals, and the chemical industry. The various weighing systems, solids flowmeters, and the more frequently used liquid/gas mass flowmeters are discussed. The magnetic coupling between the motor and the impeller is provided by means of a hysteresis clutch which transmits a constant torque from the motor to the impeller. One of the earliest methods of mass flow determination was to install two separate sensors—one to measure the volumetric flow, the other to detect the density of the flowing stream—and then use the two transmitter signals as inputs into a mass flow computing module. The impeller-turbine-type mass flowmeter uses two rotating elements in the fluid stream, an impeller and a turbine. Both elements contain channels through which the fluid flows.
