摘要 |
PCT No. PCT/FR91/00532 Sec. 371 Date Feb. 26, 1992 Sec. 102(e) Date Feb. 26, 1992 PCT Filed Jul. 2, 1991 PCT Pub. No. WO92/00492 PCT Pub. Date Jan. 9, 1992.The installation serves to adjust the flow rate of air in a network of ducts such as a mine. It comprises a fan (10) provided with an electric motor (16) powered at a variable frequency. The installation also includes a converter having an adjustable output frequency and measuring means (12, 22) for measuring the flow rate and the total pressure supplied by the fan. It also includes a processor (20), a memory (26) for storing in digital form at least one total-pressure/flow-rate characteristic curve, and optionally a pressure/flow-rate characteristic curve of the fan at at least one predetermined speed; means (30) for displaying said curves; and data input means enabling a reference value (Qc) to be given to the flow rate to be conveyed by the network, the central calculation unit (14) being designed to calculate the resistance (R) of the network and the flow rate (Q) flowing therethrough at a given instant on the basis of signals provided by the measuring means, and being designed to calculate the speed to be given to the fan by interpolation on the basis of the results of the preceding calculation and of the reference value for the flow rate.
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