CORROSION PREVENTING METHOD OF TOWER TOP CONDENSING APPARATUS OF EVACUATED DISTILLATION TOWER

摘要

PURPOSE:To effectively prevent the corrosion in a condensing apparatus having multiple stages of condensers, in said condensing unit, by circulating part of the collected condensed water to the condensers. CONSTITUTION:Since a neutralizing corrosion preventing agent is injected into the fluid at the inlet of the 1st stage condenser 3, it is virtually ineffective in the 2nd and subsequent stage condensers for the condenstion of the top gas of a evacuated distillation tower 1. Thereupon, in order to utilize the corrosion preventing agent entered the condensed water of the 1st stage for the 2nd and subsequent stages, part of the condensed water collected in a receiving tank 8 is recirculated to the 2nd and subsequent condensers. For example, the condensed water of around 6.5pH in which a relatively large amount of the corrosion preventing agent exists in the receiving tank 8 is circulated to the condensers 5, 7 by way of a pump 9, discharge piping 12 and circulating piping 11. Since this causes not only the pH in the water in the condensers to be increased but also the corrosion preventing agent to be introduced therein, it acts extremely effectively for prevention of corrosion.