Device and method for even distribution of pneumatic flow field

The invention relates to a device with a pneumatic flow field in uniform distribution and a method; the device comprises an inlet gas flue communicated with the top of an reactor, a curved conduit, a vertical gas flue and a diversion component arranged in the curved conduit; the diversion component is a group of curved arc guide plates which are arranged successively along with the radius of the curved conduit from the inner side to the outer side of the curved conduit; a gas for a smoke gas passage is arranged between the adjacent curved arc guide plates; the end of the smoke gas passage, into which the smoke gas enters, is an air inlet; the end of the smoke gas passage, from which the smoke gas overflows, is an air outlet; space between the air inlets is larger than the space between the corresponding air outlets; and the space between the air outlets is increased gradually from the inner side to the outer side of the curved conduit; the both ends of the curved arc guide plates are connected with the inwall on the both ends of the curved conduit. The diversion device of the invention has the advantages of simple structure, cheap fabrication cost and easy adjustment, and is capable of improving the uniform distribution of the smoke gas in a SCR smoke gas denitration system so as to notably increase denitration efficiency.