METHOD OF MEASURING FLOW RATE AND CALORIFIC VALUE OF STREAM OF POWDERED COAL AND DEVICE FOR REALISING SAID METHOD

摘要

FIELD: physics. ^ SUBSTANCE: powder stream being measured is passed inside three tubular electrodes 4, 5, 6 separated by insulation inserts. Measurement is carried out by applying two different voltage values across electrode 5 from a power supply 2 and determination of conductivity of the stream from the difference in corresponding current values in the electrode circuit. Voltage values from the power supply are switched at the same phase angle value of the voltage sinusoid of the mains. Storage of corresponding current values in the circuit of the middle electrode 5 after switching voltages is done with delay which is greater than or equal to duration of the transient process of measuring current caused by capacitance of the cable connecting the middle and the outermost electrodes 4, 6 with the power supply and measuring circuit 3. Calorific value (ash content) is measured at constant mass flow rate of the powdered coal. ^ EFFECT: increased reliability and accuracy of determination. ^ 2 cl, 2 dwg