Patent ID: 7300000

Claim:
An internal cleaning apparatus comprising: a rotary shaft having a liquid flow passage and being axially rotatable; a revolving rotary shaft having a liquid flow passage connected to the liquid flow passage of the rotary shaft, being provided in a direction substantially perpendicular to the rotary shaft, and being revolvable about the rotary shaft and axially rotatable; a nozzle being provided at a leading end of the revolving rotary shaft for ejecting a liquid, which is supplied from the liquid flow passage of the revolving rotary shaft, while revolving around the revolving rotary shaft; and a gas flow passage being provided along the liquid flow passage of each of the rotary shaft and the revolving rotary shaft from a gas inflow opening provided in the rotary shaft, wherein the nozzle comprises a smooth nozzle which is flattened in a direction parallel to the revolving rotary shaft, and nozzle comprising: an ejection tip being provided at a tip of the liquid flow passage for ejecting the liquid; and a communication path communicating with the gas flow passage, and wherein a gas-liquid mixture flow, having a gas supplied from outside an object to be cleaned mixed with the liquid ejected from the ejection tip in the nozzle, is ejected from the nozzle.