Babcock-Hitachi Kabushiki Kaisha

Ryosuke Nakagawa

Satoru Shishido

Toru Ogasahara

Hiroshi Yamakaji

Tetsurou Hikino

There is provided a denitrification apparatus capable of reducing NOx from a combustion facility and preventing evaporation of a reducing liquid in a lance and an injection nozzle in the combustion facility in operation at a low load by adjusting concentration of a reducing agent, thereby achieving complete evaporation of the reducing liquid in an exhaust gas duct. The denitrification apparatus of the present invention includes: a nozzle for spraying a reducing liquid containing a reducing agent for reducing nitrogen oxides in exhaust gas discharged from a combustion facility into the exhaust gas by using a flow of gas; a gas supply unit for supplying the gas to the nozzle; a reducing liquid supply unit for supplying the reducing liquid to the nozzle; and a concentration control unit for adjusting concentration of the reducing agent on the basis of a temperature of the exhaust gas and a supply amount of the reducing liquid by supplying a diluting liquid to the reducing liquid so that the reducing agent is not vaporized in the reducing liquid supply unit.

Denitrification apparatus

An exhaust smoke denitrating apparatus in which using an NHinjection unit, compressed air is fed from blower to ejector for extracting of exhaust gas from HRSG1, and with thus obtained mixed gas, NH-containing gas is produced from NHwater by NHwater evaporator, the NH-containing gas injected through NH-containing gas injection nozzle of the HRSG1 disposed on a front stream side of denitration catalyst layer. As any high-temperature exhaust gas is cooled and diluted by compressed air, there is no danger of oxidation of NHduring the stage of evaporation of NHwater. The moisture level of exhaust gas can be lowered, thereby enabling inhibition of any drain generation in exhaust gas extraction piping. Air warming within NHwater evaporation system can be carried out at an early stage. The temperature of NH-containing gas obtained by evaporation of NHwater can be lowered, and a lowering of thermal stress within NH-containing gas piping can be easily accomplished, so that denitration of exhaust gas can be easily accomplished. Even when sulfur oxides are contained in exhaust gas, it is feasible to avoid any problem of clogging of the NHwater injection nozzle.

Growing community of inventors

Kanagawa, Japan

Ryosuke Nakagawa