31-07-2014, 02:28 PM
Research on design of roof and bottoms for flat bottom cylindrical vessel
Research on design.pptx (Size: 203.03 KB / Downloads: 13)
Dome roof
Objective:
To checked the possibilities to use steel dome roof as cover of aboveground cylindrical tank with V=70000 m3 capacity and diameter D=64 m.
Conclusions :
Steel dome roofs can be used successfully to cover tanks with diameter of the shell D ≤ 64 m, e.g. capacity V ≤ 70 000 m3.
Considering the higher requirements for decreasing of vapor leaks in the atmosphere, this type of roofs can work under increased internal pressure as well as with the mounted internal floating roof in the tank. So they are better solution than supported cone roofs of the tanks with big diameters.
Buckling analysis of large scale oil tanks with a conical roof subjected to harmonic settlement
The buckling behaviour and the critical harmonic settlement of the tank with the conical roof for different wave numbers are analyzed.
The results show that buckling occurs on the roof when the wave number is small, while it changes to the shell when the wave number is large.
WIDTH OF ANNULAR BOTTOM PLATES
During the exploitation empty steel tanks could be exposed to loads that can provoke overturning or sliding. Usually tank’s movement do not leads to destruction but it could tear shell in connections with external pipelines. Therefore all steel tanks should be assured against uplift, overturning or sliding.
Peripheral part of bottom with its thickness, width and yield strength participates in forming of stabilizing forces that hold the tanks in design condition.
Conclusions:
Calculated width L of the assisting part of the bottom does not have permanent value. When the loading upon it is fixed, it depends on the yield strength Ry and width te of the annular bottom plates. Changing these parameters we can provide total stability of the tank when bigger quantity of the product is engrossed. In this way we do not need to increase the thickness of the shell and/or anchoring the tanks.