Silencer for sealed pipeline

The invention discloses a sealed pipeline silencer applied to the technical field of pipeline silencing equipment, and the device can drive a sealed rotating pipe and a discharge pipe to rotate through the gravity of a counterweight transverse block when the silencing performance is reduced due to the fact that impurities in the air are attached to the inner surface of a silencing switching piece, so that a reminding assembly is inverted after the discharge pipe rotates, and the silencing performance is improved. When the sound attenuation switching piece needs to be replaced, light of the reminding lamp is turned on, nearby personnel are reminded, workers are prompted to replace the sound attenuation switching piece in time, meanwhile, when the sealing rotating pipe rotates, the sealing plate rotates together, the auxiliary sound attenuation cotton is driven to rotate through the fixing rod, and due to the fact that the contact face between the main sound attenuation cotton and air is the largest when the ma