CLOSED LOOP CONTROL OF COMPRESSIBLE FLUID ADDITION TO A MIXTURE OF SUCH FLUID AND A LIQUID

摘要

In reaction injection molding facilities of the recirculation type, a closed loop system controls the addition of a gas to a mixture of liquid and gas. The system takes a sample volume of the liquid and forces a plunger into the sample volume. The distance travelled by the plunger between two preset pressures of the sample is measured and compared to a reference distance to get a control signal that is used to operate a valve that controls gas admission to the mixture.