Analysis and Measurements from a Prototype In-Line Thermal Solids Mass Flowmeter in an Industrial Scale Dilute Phase Pneumatic Conveying System

Abstract

The in-line measurement of solids mass flow rate in a prototype industrial scale pneumatic conveying pipeline by a thermal method has been investigated over a range of dilute conveying conditions. A thermal method of determining solids mass flow rate should, in principle, be capable of achieving a reliable measurement regardless of; inhomogeneities in solids' distribution, irregularities in velocity profile and variations in particle size or shape. The instrument described in this article operates by the injection of heat energy into the pipeline by way of a heated section and measuring the resultant change in solids' temperature using infrared sensors. Initial results from the thermal instrument are compared with measurements from a gain in weight system showing good correlation. The importance of sensor window condition and temperature on measurement is discussed.

Development of a Particulate Solids Thermal Mass Flowmeter

“…Using the energy balance method (McGlinchey et al, 2013), the following equation was used to calculate a factor corresponding to the mass flow rate of solids measured by the thermal instrument. The rate at which heat is transferred to the system is given by:…”

“…The experimental system is the same as that described in a previous publication (McGlinchey et al, 2013). The pipeline is of mild steel nominal bore 50 mm, with a total length of about 50 m, of which 5 m is vertically up, the remainder in the horizontal plane, and included five 90-degree standard radius bends.…”

“…The operation of the thermal mass flow meter was further investigated with experiments conducted under dilute phase flow conditions, conveying ordinary Portland cement on an industrial-scale pneumatic rig (McGlinchey et al, 2010;McGlinchey et al, 2013). Using an energy balance approach between the heat entering the system and the heat taken by the gas-particulate mixture, a measure of the mass flow rate was obtained which was then compared to measurements obtained from load cells.…”

Concentration measurement with thermal probe for pulverized coal in the pneumatic pipeline of power plant

“…The capacitive method [3][4][5][6], electrostatic method [7], electromagnetic method [8], optical method [9], acoustic method [10,11] and radiometric method [6,12] are volume-dependent ones. The Coriolis method [13], pressure drop method [6,14], gravimetric method [15,16], and thermal method [17][18][19] belong to the mass-dependent category.…”

“…Consequently, the thermal probe is developed for the powder concentration measurement in pneumatic pipes. Due to the wear problem in pneumatic pipes, all the thermal sensors concerned are nearly non-intrusive types in the published literature [2,[17][18][19]. The non-intrusive thermal method generally operates by the injection of heat energy into a fluid field and measuring the resultant temperature difference [19].…”