Soot blower

A soot blower in which a heat transfer tube of a heat exchanger is arranged inside a pressure vessel, and gas for cleaning is injected toward the heat transfer tube from an injection pipe that is provided to be movable into and out of the pressure vessel, the soot blower comprising:

• a cylindrical casing provided to surround an insertion hole on the pressure vessel side into which the injection pipe is inserted, and to extend outside the pressure vessel, the injection pipe being inserted into an inside of the casing;
• and
• a support part provided inside the casing to guide movement of the injection pipe and to ensure airtightness between the casing and the injection pipe, wherein
• the casing includes a connecting pipe that communicates with an inside of the pressure vessel and a seal box that is connected to a side, away from the pressure vessel, of the connecting pipe,
• airtightness between the injection pipe and the seal boxes on a rear end side and a distal end side of the seal box is ensured by a gland packing and the support part, and
• the soot blower comprises
• a first gas supplying device arranged inside the seal box between the ground packing and the support part to cause the injection pipe to generate a jet stream so that deposit adhering to a surface of the injection pipe is blown off;
• and
• a second gas supplying device arranged inside the seal box between the ground packing and the support part to supply gas with a pressure higher than a gas pressure inside the pressure vessel, wherein
• the first gas supplying device supplies gas with a pressure higher than the pressure of the gas supplied by the second gas supplying device.