Analytical instrument null in order to execute manner and this manner which analyze the chloride ion which exists in underwater of the head of the distilled tower of the hydrocarbon continually

摘要

PURPOSE: To limit corrosion of a circuit and a capacitor at the head part and enhance the durability by removing hydrocarbon and suspension substances from a sample and entraining hydrocarbon and the residue thereof by blowing nitrogen to the sample. CONSTITUTION: A circuit 18a provided with a chloride analyzer 9 is coupled again with a circuit 18b provided with a pH meter 8 at a duct 19 and the condensate is fed to a processor. In order to limit corrosion for the entire circuit at the head section of a distilling tower 3, ammonia NH3 is injected by a conduit 20 and the pH of condensate at the spherical head section 7 is sustained at about 6. Injection is controlled based on a measurement of pH obtained from the pH meter 8. First injection of anticorrosives through a duct 21 and second injection through a duct 21', as required, are performed at the level of an air cooler 6 so that corrosion due to first droplet containing hydrochloric acid on the order as high as several hundreds ppm is limited. This injection supplements injection of soda for preventing corrosion.