1.jack-up 和semi-sub的压载系统应该是不同的,semi-sub的Pontoon一直在水中,所以需要向上打水。它用的是self-priming ballast pump, 而jack-up 上用的sea water pump,它不需要向上打水。我这样说对吗?
answer: self-priming ballast pump is generally used in ballast system. The self-priming device is just a air driven ejector.
For jack up unit, the preload system is instead of ballast system, There will be installed a submersible pump for sea water facility using. including preload , ballast , fire fighting and sea water cooling system etc.
2. The flow rate in pipe line relies on the flow type.
For instance, the oil , sea water, fresh water, air or some folw containing solid.
Generally,
for water , velocity is 2~4m/s
for air, velocity is 20~30m/s
Further more, the velocity at pump suction side is generally lower than discharge side for avoiding cavitation.
在不同的吃水的时候用高低位海底门.
通常船舶在正常航行时,用低位的,进出港用高位的,避免泥沙吸入。
在钻井平台中的海底门和船舶的不太一样,有好多个,总的原则是保证所有海水系统和冷却设备的流量,形状也各式各样。