Desulfurization and denitrification integrated device for smoke

The utility model relates to a desulfurization and denitrification integrated device for smoke. The device comprises a draught fan, a bypass baffle door, a raw smoke baffle door, an outlet baffle door, a chimney, a flue inlet, an ammonia pump, a process water pump and an ammonia and oxygen mixed gas ventilator, and further comprises a heat exchange device, a desulfurization tower and a denitrification mixing device. The draught fan divides the flue into a raw smoke flue and a bypass flue and is respectively provided with the bypass baffle door and the raw smoke baffle door. The bypass flue is connected with the chimney. The heat exchange device is a shell-and-tube heat exchanger which is connected with inlet smoke of the raw smoke baffle door. The tube pass outlet is communicated with a flue inlet of a desulfurizing tower. The tube pass inlet is communicated with the smoke outlet of a mixing device. The heat exchanger is further connected wit the outlet baffle door. The ammonia pump and the process water pump