| 摘要 |
<p>Apparatus for projecting a flexible lance selectably through a tube forming one of an array of said tubes in a heat transfer unit (6) while said heat transfer unit (6) remains in service, said apparatus comprising storage means (1) for said lance whereby said lance is extended from or withdrawn back to said storage means (1), guide means (3, 5) extending from said storage means (1) through which said lance moves during extension or withdrawal, positioning means connected to a distal end of said guide means to position said distal end selectably in line with the tube through which the lance is to be projected, said apparatus being characterised in that at least said positioning means and at least a portion of said guide means is located within a header space of said heat transfer unit (6), said portion of the guide means located within said heat transfer unit including at least one flexible zone, and that the said storage means (1) and a second portion of said guide means is located within a substantially sealed housing (4), and fluid communication means (9) is provided to enable fluid from said header space to be circulated through said substantially sealed housing (4).</p> |
