US 5,478,544 A · Method for producing sodium perborate monohydrate

Abstract

Method and apparatus for producing sodium perborate monohydrate by dehydrating sodium perborate tetrahydrate in a fluid bed with heated air. Contact surfaces are arranged inside the fluid bed whose total area is the same as up to 500 times the area of the approach-flow bottom of the fluid bed. The contact surfaces are advantageously designed as heat exchangers whose surface temperature is adjusted to maintain 90.degree. to 110.degree. C. at the contact surfaces. The method results in a sodium perborate monohydrate with especially high abrasion resistance. In addition, the energy requirement is lower than that provided in the previously known method commonly used in the industry.

Claims20

Dependent claims

A method of producing sodium perborate monohydrate by dehydrating sodium tetrahydrate in a fluid bed with heated air which comprises:

introducing heated air so as to form a fluid bed with the heated air being between 80.degree. and 220.degree. C. and the temperature of the fluid bed being between 40.degree. and 90.degree. C.;
and
introducing sodium perborate tetrahydrate into the fluid bed and passing the heated air and sodium perborate tetrahydrate by contact surfaces arranged within the fluid bed such that the sodium perborate tetrahydrate is dehydrated to form sodium perborate monohydrate, and wherein the fluid bed has a first and a second temperature zone formed between an inlet and an outlet location of said perborate, and said first zone being cooler than said second zone such that in the first zone the introduced perborate is transformed so as to have a layer of sodium perborate monohydrate surrounding a thicker nucleus of sodium perborate tetrahydrate.

A method of producing sodium perborate monohydrate by dehydrating sodium perborate tetrahydrate in a fluid bed with heated air which comprises:

introducing heated air so as to form a fluid bed with the heated air being between 80.degree. and 220.degree. C. and the temperature of the fluid bed being between 40.degree. and 90.degree. C.;
and
introducing sodium perborate tetrahydrate into the fluid bed and passing the heated air and sodium perborate tetrahydrate by contact surfaces arranged within the fluid bed such that the sodium perborate tetrahydrate is dehydrated to form sodium perborate monohydrate, and wherein dehydration is carried out in a longitudinally extended, single-to-multi zone fluid bed dryer with said contact surfaces spaced at least within one zone of said dryer and wherein no contact surfaces are arranged in an area or zone of infeed of the sodium perborate tetrahydrate into the fluid bed or in an area wherein the supplied sodium perborate tetrahydrate still does not exhibit any sodium perborate monohydrate casing layer.

Dependencies are inferred from the claim text.

Method for producing sodium perborate monohydrate

Life of this patent

Method for producing sodium perborate monohydrate

Life of this patent

Abstract

Claims20