| 摘要 |
<p>The method includes comparison of the measurement error with a step error revealing a blockage in or loss from the transport pipe and the trigger of an alarm signal if the measured error greater than the step error. A first value of the specific flow is produced from the following: Qi = ( DELTA P -bT) divided by a, where 'a' is a parameter determined from each calibration and 'b' is a constant determined at startup. The calibration operation consist of emptying a predetermined volume of material and to determine the apparent specific flow (Qm) at the material output from the variation in weight of the volume as a function of time. The speed of extraction of the material volume is regulated so as to maintain a constant load loss ( DELTA P) in the pipe. Determine the mass volume of the material (p) and determine the parameter 'a' as a function of the mass flow, loss of load and temperature measured. Method of continuos measurement of a specific flow of a pulverized material circulating in the presence of air in a pneumatic transport pipe: (a) continuously (24,26) determine the load loss ( DELTA P) and the temperature (T) of the air in the pipe (18), a first value (Q1) of the specific flow is deduced (27); continuously determine (25) the flow volume (Qv) of the material, a second value (Q2) of the specific flow is deduced (28) from the flow volume taking into account the mass volume (p) of material; compare the first and second values and if a difference is measure is detected (30) carry out a calibration operation (32) for the specific flow so as to determine a new value of mass volume for the material (p) an a parameter (a) for calculation of the mass flow as a function of the load loss ( DELTA P)</p> |
