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storage and transportation of liquid carbon dioxide. The tank is installed on prepared
supports of road vehicle. Once installed, it is intended to be used during its operating life.
Figure 8: Transportable storage tank for liquid carbon dioxide
Technical characteristics of the tank are:
–
Maximum allowed operating pressure 2.0 MPa
–
Test proof pressure 2.6 MPa
–
Range of service temperature ± 30
°
C (
±
3
°
)
–
Working medium non-toxic, non-flammable, non-explosive
–
Capacity 21 m
3
–
Empty vessel mass 4400 kg
–
Maximum mass of loaded vessel 24840 kg
According to general and location factors, the tank belongs to pressure vessels class II.
Loadings and stresses for calculation
Loadings of movable pressure vessel, given in corresponding standards, are defined
for design, calculation and construction for liquid carbon dioxide. Depending on the type,
purpose and class of the vessel, following loading has to be taken into consideration:
1.
uniform loadings caused by internal pressure,
2.
dynamic and impact loadings including rapid pressure changes,
3.
loadings induced by static effect of working fluid,
4.
loadings by mass of vessel and the mass of working and test fluid,
5.
loadings induced by pipelines, accessories and insulation,
6.
loadings induced by wind,
7.
loadings induced by earthquake,
8.
thermal stresses,
9.
local stresses on the places of nozzles or supports,
10.
loading induced by the elevation of empty tank.
During its working life, this tank is exposed to all cited loadings, but dominant loading
are under 1, 3, 4, 9 and 10. The rest, because of their small impact on strength, toughness
and stability of the tank, are not taken for calculation.
As uniform loadings by internal pressure is taken only test proof pressure of 2.6 MPa.
Loadings by dead weight of vessel and the mass of working and test fluid of 24840 kg
(4400+20440), in addition to effect of internal pressure (2.6 MPa) are used in item 4.
Local stress distribution on the locations of nozzles or supports, item 9, is partly taken
according specific modelling concept of the tank, with possible upgrading of existing
nozzle for more accurate calculation, overcoming stress concentration effect.