Procedure for burning black liquor in soda boilers and soda boiler for burning black liquor

摘要

PCT No. PCT/SE92/00134 Sec. 371 Date Aug. 27, 1993 Sec. 102(e) Date Aug. 27, 1993 PCT Filed Mar. 4, 1992 PCT Pub. No. WO92/16688 PCT Pub. Date Oct. 1, 1992.The invention relates to a method of firing black liquor in recovery boilers where the intention is to obtain fumes having a low content of nitrogen oxides (NOx). A part of the combustion air is added as a last portion at a very high level so that a reducing atmosphere will exist in a very great part of the boiler for a long time period, e.g. at least 3-5 seconds.