FINITE ELEMENT ANALYSIS: PRESSURE VESSEL WITH ANGULAR LEG .
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014ISSN 2278 – 0149 www.ijmerr.comVol. 3, No. 3, July, 2014 2014 IJMERR. All Rights ReservedResearch PaperFINITE ELEMENT ANALYSIS: PRESSURE VESSELWITH ANGULAR LEG SUPPORTSAmit Patil*1 and Amol Kolhe2*Corresponding Author: Amit Patil amitpatil1984@gmail.comThe objective of the pressure vessel is to have production of phenol and acetone. Cumeneprocess is an industrial process of producing phenol (C6H5-OH) and acetone (CH3-CO-CH3)from benzene (C6H6) and propene (C3H6). The term stems from isopropyl benzene or cumene(C6H5-CH (CH3)2), the intermediate material during the process. With the help of this processtwo relatively cheap materials, benzene and propene are converted into two more valuableproducts such as phenol and acetone. For this process other required reactants are oxygenfrom air and small amounts of a free radical initiator. The pressure vessel is being designed toimplement the cumene process. The process is extremely sensitive to pressure and temperatureconditions and requires a lot of control systems to monitor it. These control systems are to beplaced below the vessel for effective monitoring.Keywords:Non-linear, Supports, Stability, Vessel, FEAINTRODUCTIONequidistance from each other. However, acustom made pressure vessel has beenordered for the cumene process. The custommade vessel has to have a lot of controls forthe cumene process; hence 8 legs are notfeasible. Six legs support with a nonsymmetric distribution was tried out initially.However the current requirement is to havemore floor space.Type of support used depends on theorientation and pressure of the pressurevessel. Support from the pressure vesselmust be capable of withstanding heavy loadsfrom the pressure vessel, wind loads andseismic loads. Pressure on pressure vesseldesign is not a consideration in designingsupport. Temperature can be a considerationin designing the support from the standpointof material selection for the different thermalexpansion. The current range of PressureVessels in the market of AZ’series, comeeither in skirt support or supported by 8 legs1OBJECTIVE OF WORKTypically most of the pressure vessels areeither skirt or leg supported and observationis that legs are primarily vertical. However inAsst. Professor Department of Mechanical Engineering, Pad. DR D Y Patil Institute Engineering & Technology, Pimpri, Pune, India.533
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014case vertical expansion of the vessel eitherdue to thermal expansion or due to verticalloading the legs are susceptible to buckling.Hence, objective of this work is to determinewhether creating an angle in the legs incombination with unsymmetrical distributionaffects the structural stability of the system.support from end of the vessel to the lengthof vessel have been outlined. This paper hasbeen a basis for deciding the support lengthand total length of vessel.LITERATURE SURVEYN EI-Abbasi et al. (2000). A three-dimensionalfinite element analysis is made of a pressurevessel resting on flexible saddle supports.The analysis is carried out using a newlydeveloped thick shell element and accountsfor frictional contact between the support andthe vessel. The seven-parameter shellelement is capable of describing the variationof the stress and the strain fields through itsthickness. A variable inequalities basedformulation is utilised for the accuratedescription of this class of frictional contactproblems. Different pressure vesselconfigurations are considered and theresulting contact stresses are examined. Theeffect of saddle radius, saddle width, plateextension, and support overhang on theresulting stress field in both the vessel andsupport are evaluated and discussed. Sincewe are having leg supports for our pressurevessel and for constant single pressurevessel analysis is done.Three Dimensional Finite ElementAnalysis of Saddle SupportedPressure VesselsAfter going through various literatures onpressure vessel supports some of theselected papers are cited below and whichare considered as basis for developingstructural analysis methodology for verticalpressure vesselsFlexible Saddle Support ofHorizontal Cylindrical Pressure VesselK Magnucki et al. (2003) have reported thatthe pressure vessel was treated as anintegrated system, including the deformablesupport with stiffness adjusted to minimizethe stress concentration in the vessel shell.The support should be of appropriate shape.Simple design and suitable thickness relativeto thickness of vessel shell. The use ofsupports of high stiffness was certainlyunfavourable taking into account the strengthof vessels.Stress Distributions in a HorizontalPressure Vessel and Saddle SupportsAnalysis of Axisymmetric ShellStructures in Axisymmetric Loadingby the Flexible MethodShafique M A Khan (2010) has mentionedthat the analysis of stress distribution inhorizontal pressure vessels and saddlesupports. A quarter of pressure vessels havebeen modelled with realistic details of saddlesupport. Physical reasons for favouring ofparticular value of ratio of the distance ofTroy Alvin Smith (2008) has presented thatthe method developed for the static stressand deformation analysis of axisymmetricshells under axisymmetric loading byreduction of the shell to ring sections. The534
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014Here design challenge inclined nature ofvessel as, ASME code enables design ofHorizontal or a Vertical vessel but there wasno provision for an Inclined Vessel in it. Theabove paper suggests structural analysis forinclined pressure vessel which is close withour vessel having inclined leg supports whichare under consideration.distribution of stresses in the meridionaldirection of the ring element is assumed tobe linear with each element. By using thederived influence coefficients, the unknownforces at the juncture of the ring elementsare found by the standard flexibility methodof indeterminate structural analysis.Subsequently, the displacements and internalstresses.Stresses in Large HorizontalCylindrical Pressure Vessels onTwo Saddle SupportsStability of Thin Walled HighPressure Vessels Subjected toUniform CorrosionL P Zick (1951) has presented thatapproximate stresses that exist in cylindervessels. Supports on two saddles at variousexist in cylinder vessels supported on twosaddles at various locations knowing thesestresses. It has possible to determine whichvessels may design for internal pressurevessels and to design structurally adequateand economical stiffing for the vessels whichrequire it. As far as vertical pressure vesselis considered the stress at each leg and shellcontact will decided the stability of vessel.E Gutman et al. (2000) have addressed thatthe stressed state in real metal constructionchanges in the process of operation evenunder permanent external loading. It takesplace due to changes in the cross section ofthe loaded elements resulting from thesurface corrosion. This paper presented amethod for determine the critical time ofstability loss in thin walled high pressurevessels subjected to uniform shell. Since ourpressure vessel is supported with I sectionbeam and uniform shell structure resultinginto stability and safe design.Support Leg Stress in PressureVessels Mounted on Arbitrary LegsSubjected to Lateral LoadingsStructural Analysis of InclinedPressure Vessel Using FEMCai Zengshen and Lin Jun (1966). A pressurevessel mounted on arbitrary leg-typesupports forms a complicated support systemwith respect to lateral loadings such as windloads and horizontal seismic motion whichdo not have a predefined direction of actionand this problem has not been solved exactly.In the present paper an exact solution is firstlyproposed which is derived from an arbitrarynumber of legs with the leg inclined at anarbitrary angle with the horizontal. Thesolution showed that: (1) in the general caseR M Tayade et al. (2012) have presentedinclined pressure vessel (IPV) study usingfinite element analysis using ANSYS to findout stresses in the vessel for its structuralstability was done in this paper. Inclinedpressure vessel was used for production ofnitrous oxide by ammonium nitrate pyrolysisreaction by passing the steam at around200 C and 1.37895 MPa over the ammoniumnitrate contained in the cylindrical vessel.535
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014VIII division 2 and IBR (Indian BoilerRegulations) standards. The stress analysiswas carried out for this support using ageneral purpose FEM code, ANSYS macros.The coupled field (Structural and Thermal)Analysis was carried out for skirt support tofind out the stresses in the support. Theanalysis results were compared with ASMEcode allowable stress. The above paper givesanalysis for skirt support and resulting stressinduced in the support with ASME section VIIIdivision 2 and IBR (Indian Boiler Regulations)standards. With similar approach analysishas been performed on inclined leg supportswith the help of FEM method.as to the support systems, the mostvulnerable direction of the horizontal loadingwhich maximizes support leg stress is not inthe symmetrical plane of the system (2) themost vulnerable direction is independent ofthe number of the legs in the system and (3)it is not the best case for the system that theangle between the legs and the horizontaldirection should be 90 . By numerical results,when the angle is about 87 the support legstress level is near to its lowest value. Sincethis paper features about the stress inducedin the legs due to lateral loading which willgive exact idea about possible values ofstress as in case of pressure vesselsupported by angular positioning of legs.DESIGN CONSIDERATIONSStress Analysis of Conical ShellSkirt Support for High PressureVessel Using Finite Element MethodDesign PressureA vessel must be designed to withstand themaximum pressure to which it is likely to besubjected in operation. For vessels underinternal pressure, the design pressure isnormally taken as the pressure at which therelief device is set. This will normally be 5 to10 per cent above the normal workingpressure, to avoid spurious operation duringminor process upsets. When deciding thedesign pressure, the hydrostatic pressure inthe base of the column should be added tothe operating pressure, if significant. Vesselssubjected to external pressure should bedesigned to resist the maximum differentialpressure that is likely to occur in service.Vessels likely to be subjected to vacuumshould be designed for a full negativepressure of 1 bar, unless fitted with aneffective, and reliable, vacuum breaker. Thepressure inside our vertical pressure vesselis taken as 150 Mpa.K Tamil Mannan et al. (2009) Pressure vesselis a closed cylindrical vessel for storinggaseous, liquids or solid products. The storedmedium is at a particular pressure andtemperature. The cylindrical vessel is closedat both ends by means of dished head, whichmay be hemispherical, ellipsoidal. Thepressure vessels may be horizontal orvertical. The supporting system of this verticalvessel plays an important role in theperformance of the equipment. Propersupporting system gives better efficiency. Thebottom supports are critical componentssince they are to be designed with much careto avoid failure due to internal pressure withtemperature. In this analysis, skirt support forvertical vessel was analysed as per theguidelines given in the ASME (AmericanSociety of Mechanical Engineering) section536
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014Design Temperaturesubjected to high temperature the designstress is based on the yield stress (or proofstress), or the tensile strength (ultimatetensile stress) of the material at the designtemperature. For materials subjected toconditions at which the creep is likely to beconsidered, the design stress is based on thecreep characteristics of the material.The strength of the metal decreases withincreasing temperature so the maximumallowable design stress will depend on thematerial temperature. The designtemperature at which the design stress isevaluated should be taken as the maximumworking temperature of the material. Thetemperature inside our vertical pressurevessel is taken as 120 C.FINITE ELEMENT ANALYSISPROCEDUREMaterialsSelection of MaterialPressure vessels are constructed from plaincarbon steels; low and high alloy steels, otheralloys, clad plate, and reinforced plastics.Selection of a suitable material must take intoaccount the suitability of the material forfabrication (particularly welding) as well asthe compatibility of the material with theprocess environment. The pressure vesseldesign codes and standards include lists ofacceptable materials, in accordance with theappropriate material standards. The materialis selected as Structural Steel for analysispurpose.As per the ASME code for manufacturing ofpressure vessel numbers of materials arespecified but the selection depends purelyupon nature of application. In accordancewith number of material selection factors andrules and regulation led down by ASME codespecifications material need to be decided.Since this work primarily focus on the analysisof vertical leg supports. Finally end user willdecide which material to be used. Thematerial used for this vessel is structural steeland its properties are listed below.Table 1: Material PropertiesDesign Stress (Nominal DesignStrength)For design purpose it is necessary to decidea value for the maximum allowable stress(nominal design strength) that can beaccepted in the material of construction. Thisis determined by applying a suitable factor ofsafety to the maximum stress that thematerial could be expected to withstandwithout failure under standard test conditions.The design stress factor allows for anyuncertainty in the design methods, theloading, the quality of the materials, and theworkmanship. For those materials notSl.No.MaterialStructural Steel1Young'sModulus (Mpa)2e52Density (Kg/m3)78503Poissions Ratio0.34Yield Strength (Mpa)2505Tensile Strength(Mpa)460Geometry CreationThe vessel geometry modelling has beendone in Ansys 12.01 workbench itself.MeshingMeshing has been done by using the methodof Tetrahedron. The accuracy of results will537
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014largely depends upon the extent of correctmeshing. In Tetrahedron method thecomponent is been divided into small triangleon its surface which gives no of nodes andelements of that component. The meshinghas been done by changing the mesh size ofthe various component of the pressurevessel. Due to change in the density of themeshing, it results in the variation of the noof nodes and elements of the meshed parts.The result of this mesh density change affectsthe value of the stress and deformation ofthe component. For fine meshing that is forsmall mesh size the values of no of nodesand elements are high but as the elementsize is gradually increased it result in increasein the value of no of nodes and elements.For small variation in mesh size that is of 1E03 m the values are showing small variationin no of nodes and elements and also it showsthe same amount of variation in the valuesof stress and deformation for the given meshsize. But for large variation in mesh size thevalues of no of nodes and elements are alsovary in large amount.Boundary ConditionDefining correct boundary conditions isprimary requirement for all the FEA analysis.The boundary condition applied for particularanalysis must be correct or it may causemisleading results. The nature of analysis willdecide the boundary conditions need to beapplied. As in this work the leg supports aremore important from analysis point of viewand sine pressure vessel is vertically standingon ground the following boundary conditionswere applied.1. Wind load acting on the vessel2. Internal pressure of the vessel3. All the supports need to be fixed to thegroundStructural AnalysisThe Ansys 12.01 workbench will give theresults in terms of the maximum deformationas well as the stress subjected by thepressure vessel assembly. Here, in this workthere will be small increment in the angularpositioning of legs by 1 degree up to 30degree. This increment will result in theconsiderable amount of deformation as wellas stress in the leg supports. The nature ofthis analysis is based upon Section VIIIDivision I for the targeted compliance of thestress values in the pressure vesselassembly.Steps Involved in Meshing PressureVessel Assembly Creating CAD model in CATIA V5R20.Repairing CAD geometry dataImport geometryCreating simplified partsMeshing the partAfter performing the meshing it is equallyimportant that the connectivity associatedbetween the element and each node of theelement will be smooth and it will not resultinto the formation of triangular elements. Andthus we are getting desirable mesh patternfor different element.FUTURE SCOPEThe analysis is mainly focused on the amountof maximum deformation and Von MissesStress. The further study may be carried outin terms of the amount of bending stressesinduced in the leg supports for given load.538
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014CONCLUSION3. H G Willschuttz (2003), “Simulation ofScaled Vessel Failure Experiments andInvestigation of Possible Vessel SupportAgainst Failure”, Journal of NuclearEngineering and Design, Vol. 228, pp.401-414.As per the solid structural analysis performedabove it is found that the values of stress anddeformation are safe for all the values of theincrement in the angle. The analysis showsthat even though varying angle from 0 to 30degree the optimum value of stress anddeformation will be achieved for 18 degreemodel for the given boundary conditions. This18 degree model is also satisfying the projectobjective that even though creating theunsymmetrical distribution in the leg supportswill be resulting into the structural stability.Also, important consideration for this work isthe increased floor space which also can beachieved for the optimum value of stress anddeformation. So considering all above thingsthis above model is also simulated for thevarious positions of angular wind load. Thepressure vessel assembly is rotated from 15to 180 degree. This will show that the valuesof stress and deformation within this modifiedboundary condition are also within limitingvalues.4. K Magnucki, P Stasiewicz and W Szyc(2003), “Flexible Saddle Support of aHorizontal Cylindrical Pressure Vessel”,International Journal of Pressure Vesselsand Piping, Vol. 80, pp. 205-210.5. K Tamil Mannan, Rakesh Saxena, RMurugavel and P L Sah (2009), “StressAnalysis of Conical Shell Skirt Supportfor High Pressure Vessel Using FiniteElement Method Multidiscipline Modelingin Materials and Structures”, Vol. 5, pp.355-362.6. L P Zick (1951), “Stresses in LargeHorizontal Cylindrical Vessels PressureVessels on Two Saddle Supports”, TheWelding Journal Research Supplement,pp. 959-970.7. N EI-Abbasi, S A Meguid and A Czekanski(2000), “Three-Dimensional FiniteAnalysis of Saddle Supported PressureVessels”, International Journal ofMechanical Sciences, Vol. 43, pp. 1221242.REFERENCES1. Cai Zengshen and Lin Jun (1966),“Support Leg Stress in Pressure VesselsMounted on Arbitrary Legs Subjected toLateral Loadings”, International Journalof Pressure Vessels and Piping, Vol. 68,pp. 13-22.8. R M Tayade, Vinay Patil and Imran MJamadar (2012), “Structural Analysis ofInclined Pressure Vessel Using FEM”,International Journal of EngineeringResearch & Technology (IJERT), ISSN:2278-0181.2. E Gutman, J Haddad and R Bergman(2000), “Stability of thin - Walled HighPressure Vessels Subjected to UniformCorrosion”, International Journal ofPressure Vessels and Piping, Vol. 38, pp.43-52.9. Shafique M A Khan (2010), “StressDistribution in Horizontal Pressure Vessel539
Int. J. Mech. Eng. & Rob. Res. 2014Amit Patil and Amol Kolhe, 2014and the Saddl
vessel as, ASME code enables design of Horizontal or a Vertical vessel but there was no provision for an Inclined Vessel in it. The . Skirt Support for High Pressure Vessel Using Finite Element Method K Tamil Mannan et al. (2009) Pressure vessel is a closed cylindrical vessel for storing
Finite element analysis DNV GL AS 1.7 Finite element types All calculation methods described in this class guideline are based on linear finite element analysis of three dimensional structural models. The general types of finite elements to be used in the finite element analysis are given in Table 2. Table 2 Types of finite element Type of .
pressure vessel using a handbook is troublesome and not interactive. In this Paper further improvement achieve using following steps, Design Pressure Vessel as per Problem statement Geometrical model of Pressure vessel is created using CATIA V5 R19. Optimization analysis of pressure vessel is carried out for optimum wall thickness.
DESIGN ANALYSIS OF PRESSURE VESSEL USING PV ELITE A. Design of Pressure Vessel A pressure vessel horizontally placed on saddle supports was designed according to the design data input. SRAAC industry was planning to design a pressure vessel, as in need of a pressure vessel for storing chemical. As chemical storing
Toroidal Pressure vessel and Filament wound Pressure Vessel used to store CNG. The Toroidal Pressure vessel and Filament wound Pressure Vessel are modeled in 3D modeling software Creo 2.0. Theoretical calculations and analysis is also carried to determine stress and displacement values for toroidal pressure vessel.
Figure 3.5. Baseline finite element mesh for C-141 analysis 3-8 Figure 3.6. Baseline finite element mesh for B-727 analysis 3-9 Figure 3.7. Baseline finite element mesh for F-15 analysis 3-9 Figure 3.8. Uniform bias finite element mesh for C-141 analysis 3-14 Figure 3.9. Uniform bias finite element mesh for B-727 analysis 3-15 Figure 3.10.
FINITE ELEMENT ANALYSIS OF COMPOSITE REACTOR PRESSURE VESSEL By Tejas Vasant Mhetre, MS The University of Texas at Arlington, May 2018 Supervising Professor: Dr. Andrey Beyle Reactor Pressure Vessel is the container designed to hold gases or liquids above atmospheric pressure.
Table 4.1: Analytical results for stresses on pressure vessel SR. NO. Type of stress Magnitude (MPa) 1 Table 6.2. Stress Analysis of Pressure Vessel with Two 10 Hoop Stress 50.52 2 Longitudinal stress 25.26 V. MODELING AND ANALYSIS OF PRESSURE VESSEL The 3D model of pressure vessel is created using a CAD software Creo Parametric.
THE AMERICAN REVOLUTION AND CONFEDERATION, 1774-1787 87 . Thomas Paine, a recent English imntigrant to the colonies, argued strongly for what until then had been considered a radical idea. Entitled Common Sense, Paine's essay argued in clear and forceful language for the colonies becoming independent states and breaking all political ties with the British monarchy. Paine argued that it was .
