| 摘要 |
The cleaning system is for a steam generator, e.g. as used in a nuclear power station. An upright casing contg. a pipe bundle of inverted-U section. The bundle is accessible via two or more opposite apertures above the bottom, through which a high-pressure lance, sliding lengthwise and turning about its lengthwise axis, is inserted. A head fixed to the lance end has transverse spray openings and inserted between the pipes, while a suction pipe is inserted through one aperture, leading to near the bottom. - Between the sliding movement of the lance to and fro, it and the head are turned to and fro round its axis while a mean output of 200 litres per minute is sprayed. Liquid is sucked up from the bottom at a considerably faster rate than this. USAB- US4620881 A U-type steam generator is cleaned by introducing high pressure lances carrying spray heads through two accesses opposite one another above the bottom of the generator between pipes in the bundle. - The lances are simultaneously intermittently moved inwards or outwards, and swing to and fro over 180 deg. - During swinging liq. is sprayed through the heads at a pressure above 200 bars at a flow rate of over 200 (pref. 250-360) l per min.
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