| 摘要 |
<p>Metering device for metering a fluid into a liquid to obtain a treatment liquid having variable physical parameters depending on the concentration of the fluid to be metered into the treatment liquid. The device comprises a container having an inlet for the liquid, an outlet for the treatment liquid and an inlet for the fluid to be metered. First valve means provided at the inlet for the liquid are effective to control the flow of the liquid into the container according to the level of the liquid in the container. Second valve means provided at the inlet for the fluid to be metered control the admittance of the fluid to the container. Means are provided for controlling the opening, and alternately the closing, of the second valve means and comprising a member responsive to the value of one of the physical parameters of the treatment liquid to alternately control the opening and the closing of the control means for the second valve means, according to the absence, or respectively presence, of a predetermined value of one of the physical parameters of the treatment liquid.</p> |
