| 摘要 |
<p>1,071,823. Controlling the mixing ratio of liquids electrically. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V Aug. 4, 1964 [July 23, 1963], No. 30677/64. Heading G1N. The mixing ratio of two liquids being mixed is maintained constant by periodically or continuously measuring and comparing the liquid levels in each of two supply tanks as the liquids are respectively drawn therefrom. In Fig. 1 liquid level meters 9, 10 are electrically or mechanically coupled to the moving contact arms 14, 15 of variable resistors R 1 , R 2 in a bridge network so as to move the arms in accordance with the liquid level or reduction in level from a predetermined value. The mixing ratio is preset by adjustment of the values of R 3 to R 4 by a contact arm 13. Any deviation from a desired ratio unbalances the bridge and the unbalance voltage operates a controller 12, which adjusts a valve 8 to increase or decrease the rate of withdrawing liquid from tank 1, through pipe line 5 until the bridge is rebalanced. The liquids mix in pipe 7. Instead of continuous movement of the contacts 14, 15 they may be adjusted at intervals (e.g. every sec.). If more than two liquids are to be mixed there would be more than one bridge. Instead of using a bridge as a control device a double potentiometer circuit Fig.2 (not shown) may be used, which has the advantage that zero setting of the control device is independent of the initial level in the tanks.</p> |
