Design, development and construction of Hall effect-based turbine meter type to measure flow in low-cost lithium bromide salt: Proposed flowmeter and first results

Abstract

Abstract The objective of this work is the design, construction and testing of a conventional turbine-type flow meter for liquids, especially for low-cost lithium bromide (LiBr) saline solution. This meter is directly coupled to the piping, through flanged connections where the fluid flows by driving a turbine that rotates freely in the casing mounted axially inside the meter. The turbine speed is proportional to the speed of flow of the fluid in the process. A Hall effect sensor W1305347 coupled to the meter has its magnetic field changed each time one of the turbine blades passes through it, thus generating an electric pulse. The amplification is applied to the pulses that are then treated as frequency and/or current by a microcontroller that interprets the signal and provides the visualization of the instantaneous flow in the digital indicator, as well as its total in time. The proposed meter, aims to overcome difficulties encountered in measuring flow of fluids in absorption systems since the working fluid is a crystalline salt that can present formation of solid phase crystallizing at moderate values of concentration, as well as low values of working pressure and high values of viscosity of the solution. This study describes all aspects of design, construction, operation, equationing and analysis of the characteristics of the volumetric flowmeter (MedyFlow). The validation of the meter (MedyFlow) proved to be effective since the results were very close to those obtained by the ultrasonic meter with errors of less than 4% statistically proven by F-TEST.