@article{oai:sucra.repo.nii.ac.jp:00012626, author = {佐藤, 勇一 and 長嶺, 拓夫 and 永井, 純一 and 片山, 圭一}, issue = {690}, journal = {日本機械学會論文集. C編}, month = {}, note = {A soot blower is used to blow off soot on tubes in a tubular heat exchanger, or a gas heater. The soot blower has a long flexible tube, that is, a lance tube, 8 m long and 76.2 mm in diameter, which is put slowly into/out of a gas heater. Steam flows through the lance tube and is discharged at the free end to blow off soot. The lance tube, rotating slowly about its axis at about 12 rpm, is supported at an intermediate position by a support bearing, that is, a lance bearing. Vibrations and noises occurred in operation while a lance tube is being put into a gas heater slowly. They are considered self-excited vibrations due to friction between the lance tube and the lance bearing. From frequency analysis dominant frequencies of the observed vibrations are the eighth to tenth natural frequencies. Experimental study is done to clarify the mechanism of the vibration. Accordingly, backward whirling motion of a shaft is observed. As the clearance between the flexible shaft and the circular support is reduced, higher modes appear., text, application/pdf}, pages = {356--362}, title = {摩擦力の作用する柔軟回転軸の振動 : 実験(機械力学,計測,自動制御)}, volume = {70}, year = {2004}, yomi = {サトウ, ユウイチ and ナガミネ, タクオ and ナガイ, ジュンイチ and カタヤマ, ケイイチ} }