Abstract: An apparatus for cleaning hydraulic fluid includes a centrifugal fluid-spinning disk arranged in a housing, of which an upper portion forms a vapor chamber and a lower portion forms a fluid collecting basin. A vacuum pump is connected to the housing through an oil mist separator, such that water vapor is vacuumed away and hydraulic fluid collects in the oil mist separator to then be pumped away. The apparatus further includes preferably a single container that contains both the contaminated hydraulic fluid that is to be cleaned and the cleaned hydraulic fluid. A flexible inlet line and a flexible outlet line with respective hydraulic quick connectors are provided to connect the apparatus and particularly the oil container to a hydraulic system of an aircraft, for example. A high pressure pump connected to the outlet line pumps the cleaned hydraulic fluid into the aircraft hydraulic system and a pressure maintaining valve in the inlet line maintains the system pressure.

Abstract: An improved process for the preparation of 3,6-dichlorosalicylic acid by carboxylation of potassium 2,5-dichlorophenolate with carbon dioxide in xylene at elevated pressure, where the improvement consists of adding finely powdered, anhydrous potassium carbonate to the reaction mixture, whereby the yield of 3,6-dichloro-salicylic acid is significantly increased.