METHOD AND DEVICE FOR SEMI-WET TYPE DESULFURIZATION AND DUST COLLECTION OF STACK GAS

摘要

PURPOSE:To improve desulfurization rate and to reduce the consumption of calcium hydroxide by spraying water contg. alkali materials in waste gases, capturing dust and the product of reaction with a collision type preduster then heating the gases and feeding the same to a dust collector. CONSTITUTION:After part of high temp. waste gases are branched and are introduced into a drying chamber 12, they are returned into an introduction duct 2, and are introduced together with other waste gases into a spray tower 1. Slurry of calcium hydroxide, etc. are sprayed from a spray nozzle 4 and are caused to react with S compds. in the gases and the temp. of the waste gases is reduced down to within 15 deg.C of saturation temp. The product of the reaction and the coarse particles in the dust are captured in the tower 1 and a collision type preduster 13 moving in a drying chamber 2, whereby they are dried and separated. The waste gases contg. fine dust and the product of reaction are heated by heat exchanging with the preduster 13, and are introduced through a discharge port 10 then through a discharge duct 7 into a dust collector 8.