Patent ID: 6340410
Filing Date: 2002-01-22
Classification: C01B,D21C

Abstract:
Method for supplying hydrogen peroxide having a predetermined concentration to a bleaching vessel which consumes hydrogen peroxide at a variable rate which comprises:generating hydrogen peroxide having a concentration, which is greater than or equal to the predetermined supplying concentration, on the site of the bleaching vessel or in the immediate proximity of this site wherein a generation rate varies from a minimum generation rate and a maximum generation rate; temporarily storing the hydrogen peroxide thus generated in at least one holding tank; and drawing the hydrogen peroxide from the holding tank and, when the generating concentration of said hydrogen peroxide is greater than the predetermined supplying concentration, diluting said hydrogen peroxide with water to the predetermined supplying concentration, the drawing of said hydrogen peroxide being carried out at a variable rate which corresponds to said variable consuming rate, and feeding said hydrogen peroxide to the bleaching vessel wherein the consuming rate varies from a number greater than 0 to a maximum consuming rate, and the difference between the minimum and maximum generation rates is smaller than the maximum consuming rate and, wherein the liquid level in the holding tank varies between a highest level and a predetermined low level, and as soon as the liquid level in the holding tank in the holding tank becomes the predetermined low level, hydrogen peroxide having a concentration equal to or greater than the predetermined supplying concentration is drawn from a back-up tank and diluted with water to the predetermined supplying concentration when the back-up tank concentration is greater than the predetermined supplying concentration, and fed to the bleaching vessel.