DRY DESULFURIZING AND DENITRATING SYSTEM FOR WASTE GAS

摘要

PURPOSE:To decrease the total amt. of a treated gas while keeping the removal rate high and to desulfurize and denitrate the waste gas at a low cost by mixing the waste gas leaving a desulfurization tower into the waste gas current divided to the denitration tower side, injecting ammonia into the gaseous mixture and introducing the mixture into the denitration tower. CONSTITUTION:The waste gas 15 is divided into a denitration tower 35 and a desulfurization tower 25. The waste gas 15e leaving the desulfurization tower 25 is joined to the waste gas 15b separated to the denitration tower side at point 75b, ammonia is injected at point 75c, and the mixture is introduced into the denitration tower 35. Consequently, although a certain amt. of NOx is left, SOx is almost wholly removed, and the total amt. of treated gas is decreased. As a result, the scale of the entire system is reduced by decreasing the total amt. of treated gas, and the simple and inexpensive system is obtained without excessively deteriorating the denitrating and desulfurizing function.