Abstract: A process for causing gaseous trace element particles to pass from a flowing hot gas into a fine particulate material by means of water. A mixture of the hot gas and water drops is caused to flow substantially upwards at such a velocity that the water drops remain in the gas flow and for a period long enough for most of the mass of the water drops to evaporate in order to cool the gas and to increase its relative humidity. After the gases have reached their wet temperature, they are brought into a turbulent state in order to cause the dust particles and the water drops which have decreased through evaporation to impinge against each other in order to produce in the aqueous film which covers the dust particles an exothermal ion reaction between the gaseous water-soluble trace element particles and the fine particles. Thereafter, the mixture is caused to flow further in order to evaporate the remaining water by means of the heat of reaction so that a dry end product is obtained.

Abstract: The invention relates to a process and apparatus for causing the sulfur dioxide of flue gases to react to form solid sulfates and sulfites which can be separated from the flue gases. Sulfur dioxide containing flue gases (16) are directed according to the invention into one end of an oblong reaction zone (4), in addition to which pulverous calcium compounds and water are directed separately into the reaction zone at several points, and finally from the opposite end a flue gas suspension is withdrawn and directed to dust separation (5). By feeding the pulverous reagent and the water separately into the reactor 4, the problems involved in the preparing, handling and spraying of an aqueous slurry are avoided, in addition to which the retention time and the reaction conditions can be regulated easily in the oblong reactor 4.