For this application, LEWA developed a metering system with intellidrive technology:
To test whether oil components in liquefied gas have harmful effects on gas combustion engines, extremely small amounts should be guided to oil in a corresponding test stand. To do so, LEWA developed a metering system consisting of an ecoflow piston pump on a support frame, a LEWA intellidrive drive system, a storage container and the associated piping. In addition, a switch box with a control system and all required operating elements were contained in the scope of delivery.
The metering system works according to the principle of adaptive masses or volume flow control. For this purpose, a so-called h0 provision is carried out in the compression phase during continuous operation, i.e. the piston is moved to the rear dead center after the suction phase beginning at the point where the inner pressure is the same as the outer system pressure. Based on this point (h0), the calculation of the necessary stroke frequency needed to achieve the specified target volume flow (e. g. Qtarget = 1 ml/h) is carried out.
The change to the h0 value, i.e. the change in pump efficiency, that occurs due to small air bubbles, for example, is recorded for each individual pump stroke and corrected by recalculating the stroke frequency correctly (adaptive mass or volume flow control). No flow meter is used. Different parameter settings can be set on the provided operating panel.
In applications which require addition of smallest amounts of a fluid, LEWA can provide different solutions: In addition to the intellidrive technology, we offer more microflow metering pumps for different requirements such our pump series MAH, MBH, and MLM as well as the FC series. With our microflow metering solutions, you can always realize flow rates from 1 ml/h to 65 l/h at conveying pressures from 1 to 560 bar.
We will be happy to advise you on the best solution for your application!