COMPARISON OF MASS FLOW RATE SENSORS FOR GINNING STRIPPER-HARVESTED COTTON

Abstract

Real time mass flow sensors are needed at various locations in the cotton gin if process control is to reach itsfull potential. Several devices, including belt scales, light array bars and a microwave flow meter, were evaluated for theirsuitability in detecting the flow of cotton and the mass flow rates of stripper harvested cotton. The readout from the truckscales was used to provide the lot weight for the study. Although equipment problems prevented us from testing theaccuracy of the scale units under varying rate conditions, these units should provide the most accurate method ofmeasuring mass flow. The mechanical nature of the scale units, however, limits their usefulness in commercial gins whichuse primarily pneumatic systems to convey the cotton. The microwave-based sensor was unsuitable for measuring massflow but did provide an excellent indication of the presence of flow in the pneumatic pipes. The signal from the light bararray correlated very well with the mass flow rate of the cotton through the pipes (R 2 = 0.98) and requires only minormodifications to the pipes used to convey the cotton. All devices need estimates of moisture and trash content to improveaccuracy.