METHOD AND EQUIPMENT FOR THE APPLICATION OF COATINGS BY THE SETTLEMENT ON THE INTERNAL SURFACES OF TANKS AND PIPELINES

摘要

Tank (1) is filled with liquid (3) containing water to which acid (10) is added. The oxide coating along the inner surfaces of the tank (1) is removed by heating and recirculation of the liquid (3) through a filter (4) which is neutralized by the addition of alkali (12), one-fifth of the neutralized liquid (3) is discharged from the tank (1) which is filled up by concentrated metal solution (15). The temperature acidity and metal concentration of the metal in the liquid (3) are maintained to values close to the permanent, by heating and the addition of acid (10) or alkali (12) or concentrated metal solution (15), respectively. Air or steam is introduced through pipeline (5) for bleeding the tank (1) and this causes mixing of the layers of the liquid (3) and the surplus quantities of liquid and gas are discharged through another pipeline (16). When a coating with the desired thickness is formed on the inner surfaces of the tank (1), the liquid (3) is cooled and is removed, and the process is discontinued.