| abstract |
In the process, the cooking liquor is burned, magnesium oxide and sulfur dioxide contained in the resulting combustion gases are used to produce magnesium monosulfite (MgSO3) and magnesium bisulfite (Mg (HSO3) 2), part of the MgSO3 is thermally cracked and the cracked products are obtained. In order to practically completely free the hot process gas from the MgO fine dust without significant cooling and thus to reliably avoid incrustation of parts of the system during the subsequent cooling of the process gas, the hot process gas containing SO2, MgO and H2O that is formed during the splitting of the magnesium monosulfite is used for separation the MgO dust is subjected to filtration using a random fiber fleece (5; 18) and the random fiber fleece is cleaned if necessary. The filter apparatus comprises a heat-resistant housing (1) and a filter element which can be inserted into the housing (1) in the flow of the process gas to be filtered, which filter element with a random fiber fleece (5; 18) made of a high-temperature-resistant, sintered metallic material, in particular of rust-free chrome Nickel or chrome-nickel-molybdenum steels, or is equipped with a ceramic fiber fleece, devices for cleaning being provided within the apparatus. |