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发表于 2010-5-27 21:44
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来自: 中国上海
BV规范,Pt E, Ch 8, ICE Class,the ballast tanks are to be provided with suitable devices to prevent the water from freezing, which shall be so designed as to avoid any ice formation in the tank which may be detrimental to the tank. For that purpose, the following may be accepted:
- heating systems by heating coils within ballast tanks
- internal circulating/pumping systems
- bubbling systems
- steam injection systems.
Where bubbling systems are applied, following shall be complied with:
- sufficient number of air nozzles is to be distributed along the shell side bottom
- the maximum air pressure induced in the tank is not to exceed the design pressure of tank structure
- exposed vent pipe and vent heads shall be protected from possible blocking by ice
- if the bubbling systems is not supplied by a dedicated compressed air plant, the general service air system may be used for that purpose if justified that its capacity takes into account the air consumption of the bubbling system.
Where ballast water exchange at sea is accepted as a process for the treatment of ballast water, ship side ballast discharge valves are to be protected from freezing.Suitable protection shall be provided also for ballast tanks vent heads, as well as for ballast overflows where existing. |
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