The utility model discloses a sealed reaction tank, and belongs to the technical field of reaction tank sealing. The device comprises a tank body, a stirring mechanism, a sealing sleeve, a compensation
air pump, an air extracting pump, an air extracting
pipe, a second sleeve and a feeding
pipe, the second sleeve is fixedly arranged on the top face of the tank body and fixedly connected with one end of the sealing sleeve, and the other end of the sealing sleeve is fixedly connected with the stirring mechanism; the stirring mechanism penetrates through the top surface of the tank body and extends into the tank body for stirring, the stirring mechanism is rotationally connected with the top surface of the tank body, the compensation
air pump is fixedly mounted on the top surface of the tank body and is communicated with the sealing sleeve through an air supplementing
pipe, the air extracting pump is communicated with the tank body through an air extracting pipe, and a feeding pipe is arranged on the side wall of the tank body.
Pressure difference is formed in the sealing sleeve and the tank body, so that harmful gas is sealed in the tank body, the harmful gas is prevented from escaping, and meanwhile, the
retention time of the sealing effect of the reaction tank is effectively prolonged.