隔离球隔离效果分析和新型隔离器的设计

为了降低成品油管道的造价,减少混油罐的投资,提高经营效益,就必须减少混油量。降低混油量的方法主要是使用隔离球。由于隔离球易被管内壁磨损,使隔离球的直径以及隔离球与管内壁间接触环的大小都随管道的长度而发生变化;隔离球与管内壁间的摩擦力使球的前后存在一个压差,在压差作用下,再加上油品粘性和管内腐蚀凹坑的影响,产生了通过隔离球与管内壁缝隙的超前渗流和落后渗流,形成混油。而它们的差值又导致了隔离球的运行速度与油流平均速度不一致,进一步加大了混油量,使现用的隔离球很难达到满意的隔离效果。新型隔离器设计了简单的接触环宽度调节结构,使其基本保持一个定值。另外还设计了超前渗流负补偿机构,使超前渗流基本等于落后渗流。采用上述二项新措施后,能最大限度地减少超前渗流量,最大限度地使隔离器的运行速度与油流平均流速相一致,从而最大限度地提高隔离效果,降低混油量。

Analysis of Seperating Effect of Separating Sphere and Design of New Type of Seperating Unit.

Mixed oil quantity should be reduced so as to reduce the cost of product pipeline and investment of slop tanks. The main method of reducing mixed oil quantity is to utilize seperating spheres. A seperating sphere is easy to show wear due to the friction on the internal pipe wall, the following parameters should change according to the length of the pipeline: the diameter of the sphere, the size of the contact rings between the pipe wall and the sphere. A differential pressure usually occurs due to the friction force between the pipe wall and the sphere. Acted on by the condition of the differential pressure, influenced by vescosity and pits (in the internal pipe wall caused by corrosion), seepage oil (before/after the sphere) from between the sphere and the pipe wall forms the mixed oil, the differential value causes the sphere and the liquid flow at different speeds , thus enlarging the quantity of mixed oil. It is hard for the seperating sphere we have been using to reach the satisfactory seperating effect. The new type seperating unit is designed to have a simple structure for regulating the width of contact rings, which basically keep one set value. Besides, a negative structure compensating seepage oil before the sphere is also designed, which makes the seepage ahead equal to what follows afterwards. If the two measures mentioned above are taken, the quantity of seepage oil ahead can be reduced to a minimum. the sphere can be made to travel as identically as possible with the average liquid speed thus reducing the mixed oil quantity to a minimum.