| 摘要 |
In an arrangement for controlling the fibre concentration of a fibre suspension in an installation, dilution water is fed to the concentrated suspension via a line (17) from a tank (1) via an adjustable valve (11, 12) which is controlled by a concentration controller (15) which is fed, in addition to the set value, with the actual value of the concentration, measured by the instrument (13, 14) downstream of the point where the dilution water is introduced into the line (17). According to the invention, measuring elements (26 or 28, 29) are provided which emit a measured signal (27 or 30) for the concentration in a suspension tank (1) or at the outlet thereof. This measured signal is fed forward to the concentration controller (15) via the signal line (31) in such a way that, when the measured signal (27, 30) changes, the valve (11, 12) for the dilution water is adjusted in the direction opposite to that of the measured concentration change, even before a change in the concentration is detected by the measuring element (13, 14) of the concentration controller. A corresponding feeding-forward of the measured concentration value obtained at the tank (1) can also be fed forward to the controller (10) for a flow control, which may be present, for rough dilution of the suspension. The response sensitivity and stability of the control arrangement are substantially increased by the invention. <IMAGE>
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