H4CV-13-C gh speed shaft observe oil supply and heat genera Helical speed reducer H4

Flender/Flender Gear Units/Helical speed reducer H4

hate process, the main process used for annuals, most of this silicic acid ends up in the black liquor and severely limits the chemical recovery process at various stages. These difficulties become apparent every day in some pulp mills which process bagasse or reed. In this context, however, the lime sludge containing silicate has to be disposed of by dumping, due to the fact that reburning is not feasible. There has not yet been any success in economically recoverin chemicals during the proces- sing of rice straw. This means that the cookin chemicals are stif being lost in several thousand pulp mills of this kind around the world anjthe natural waters severely contaminated as result. The purpose of this project is to test the apparently romising rocess steps on semi-indus- trial scale in continuous desilicification process ungr practicarconditions, and to compile the knowledge required to desigriand operate large-scale installation. process and thus keep the environment clean at the same time. _- 2. Working steps In order to carry out semi-industrial desilicification experiments on rice straw waste liquor, pilot lant was installed by the ,,RAKTA pulp and paper factory in Alexandrta/Egypt, in which the stcicacid was to be precipitated using two different methods and removedfrom the liquor with the help of different separation devices The two precipitation methods were ) Treatment of the liquorwith flue gas containing COz to reduce the pH value and precipitate silicic acid as 9, ) Treatment of the liquor with quicklime to precipitate silicic acid as Cas1 The precipitant was separated on vacuum filters, pressure filters and centrifugal separators In addition, two-sta vacuum evaporator was connected, with which experiments on the concentration of the jesilicified black liquor were to be carried out 3. Results With the knowledge gained from this tnvesti ation, it is nowalso possible to build and operate an installation for the desilicific