Fabricated denitration reactor

The invention relates to the technical field of denitration reactors, in particular to an assembly type denitration reactor. The technical problem that when the fluctuation value of the flue gas amount is large, the fed flue gas cannot be subjected to complete reaction denitration through the constantly fed reaction gas is solved. An assembly type denitration reactor comprises a supporting frame, a first fixing shell is detachably installed on the upper side of the supporting frame, a reaction shell is detachably installed on the upper side of the first fixing shell, a second fixing shell is detachably installed on the upper side of the reaction shell, and the second fixing shell is fixedly connected and communicated with a mixing pipe; the mixing pipe is fixedly connected and communicated with a first storage tank communicated with the second feed port, and a first cylindrical plug is slidably connected in the first storage tank. According to the invention, the first cylindrical plug is pushed when the flue