Quick Reacting Magnetic Ball Valve

A quick reacting ball valve developed for a comet lander has through the support of the European Space Agency’s Technology Transfer Programme already reached the terrestrial market even without application in the aerospace industry. The mass production for the novel ball valves is presently being started.

In 1993 planning of the Rosetta mission was started. The mission was originally aimed at sending a lander to the comet Wirtanen in order to collect from its sur-face data of considerable importance for the under-standing of the origins of our solar system as well as possibly of life on our planet earth. Initiated by the plan for the lander, the Institute of Space Simulation of the Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR) started developing quick reacting valves for dosage of the gas flow in the planned cold gas ma-noeuvering nozzles of the lander.

Although in the end another control concept without quick reacting valves was realised for the comet lan-der, the development of the valve started at that time have considerably advantaged its technique. Mean-while further developments of the valve have been effected for various applications, especially the mag-netic ball valve with a very simple design for fluid and gaseous media. For opening the valve a magnetic ball is moved from the valve seat through a magnetic field. For valve closing the flow caused by the differential pressure between valve entry and exit drives the ball back to the valve seat. The valve ball is the only mov-ing part. As it is not pressed into the valve seat by springs or suchlike, the wear-out of the valve is ex-traordinarily low. The valve can without difficulty be of noncorrosive design since the fluid or gaseous media are only in contact with the valve seat, the valve ball and a guide tube.

One of the first applications is the so-called “RRV – Rapid Reaction Valve” in the automotive industry where a viscous medium is applied within extremely short time intervals and with highly precise dosage at different points of the auto body shell. Here, the basic advantages of the RRV take effect: The dosage accu-racy is notably better than state of the art and the very low switching time of less than 2 milliseconds enables high frequency. Because of the low mass of the valve assembly the acceleration loads for the robots are reduced remarkably.

Another application of the valve is in purifying contaminated water. In a reverse osmosis system where water is pressed through membranes filtering con-taminants the valve enables a most precise control of the flow rate so that a maximum capacity is achieved at best possible utilization of the membranes. Especially for this application very low reaction times of the computer-controlled Valve are required in order to prevent damage to the cell membranes. The result is a notably improved de-gree of purification of the filtered water. Presently the com-plete system is in the process of being certified by the German Technical and Scientific Association for Gas and Water (DVGW).

The RRV will also be found in agriculture, namely in areas where pesticides such as herbicides, fungicides or insecti-cides are systematically sprayed. Against the background of a further growing sensibility for environmental and food topics the application of the RRV promises a minimisation of the applied agents and thus a considerable contribution to the limitation of the impact of these agents on the environment.

These are only a few application examples. Further poten-tial customers interested in the magnetic ball valve for ap-plication in filling technology, printing industry, aviation or sorting technology are already waiting.

Category
Reference No.
SSA0005
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