Research Article Volume 6 Issue No. 6

Transcription

1 DOI / ISSN IJESC ` Research Article Volume 6 Issue No. 6 Design, Analysis and Development of Pressure Vessel Lug Support Vishal S. Telgote 1, Prof.G.E.Kondhalkar, Guide, (H.O.D) 2 Department of Mechanical Engineering Anantrao Pawar College of Engineering & Research vishaltelgote@gmail.com 1, ganeshkondhalkar@gmail.com 2 Abstract: The pressure vessel structural stability is mainly depends upon lug support of pressure vessels. The Cylindrical and other kind of vessels to be completely supported by different strategies. For structural stability of pressure vessel, it is important to work out the assorted loads subjected to supports. Generally the pressure vessels designed according to the operating conditions of temperatures and pressures. This present study deals with the FEA analysis of pressure vessel lug support. High pressure rise is developed within the pressure vessel and pressure vessel must withstand severe forces. Because of the potential impact of possible accidents, the design of pressure vessel safety is that the primary thought. In this paper the lug support which holds the pressure vessel is analyzed. It involves the modeling of pressure vessel in CATIA. The meshing and boundary condition application are going to be carried out by Hypermesh and Structural analysis of a pressure vessel with supporting lugs are going to be applied using ANSYS. Keywords: Pressure vessel, Lug Support, Catia V5R19, Hypermesh 12.0, Ansys 13 Introduction: Common supports of vertical columns are Skin supports: These are cylindrical or conical steel shells attached to the bottom tangent of vertical tall vessels. Bracket or lug support: These are commonly used to support vertical vessels of smaller heights with minor wind loads. The Brackets are attached to the vessels and rest on columns or beams. Bracket support can be easily constructed and attached to the vessels with a minimum weld length this is the advantage. The disadvantage of this type of support is that compressive, tensile and shear stresses are induced in the vessel wall as a result of eccentricity. Supports for horizontal Vessels: Common supports for horizontal vessels are ring supports or saddle supports. Two or more saddles may be used and if required stiffening rings are used to strengthen the vessel. Ring supports are preferred if support is required at more than two positions[5]. Problem statement: The pressure vessel structural stability is mainly depends upon lug support of pressure vessels. The Cylindrical and other kind of vessels to be completely supported by different strategies. For structural stability of pressure vessel, it is important to work out the assorted loads subjected to supports. Generally the pressure vessels designed according to the operating conditions of temperatures and pressures. This present study deals with the FEA analysis of pressure vessel lug support. High pressure rise is developed within the pressure vessel and pressure vessel must withstand severe forces. Because of the potential impact of possible accidents, the design of pressure vessel safety is that the primary thought. In this study the lug support which holds the pressure vessel is analyzed [1]. Mostly gases are admitted at high temperature and pressure in a pressure vessel. Due to these loadings (Internal temperature and pressure) there are several cracks/failure developed in lug supports and jointly of pressure vessel. These lug supports must be capable of withstanding heavy loads from the pressure vessel. Objectives: We can consider, the main objective of this paper is to study pressure vessel lug support design, failure analysis, re-design, proposing a prototype model and experimental testing that will withstand all the heavy loads acting on it [3] Literature Survey: (Parmar, Patel, Mevada) This paper presents the guideline in thermal analysis for dished end joint of the pressure vessel. In the pressure vessel through nozzle connections shell to a dished end the gases of temperature and pressure admitted. Due to these loadings (Internal temperature and pressure ) there are several cracks/failure developed in skirt dished end joint. With the help of correct techniques and analysis, whatever the stresses developed which can be determined and analyzed by (FEM). The stress parameters are noticing out that ought to be taken into account as a most parameter for this one and it may be reduced by optimizing. After optimization decrease the stresses of this joint due to modifying the weld size of skirt to end dished joint and additionally increase the pressure vessel life pressure vessel.(b.s.thakkar, S.A.Thakkar) In this paper, the design of pressure vessel are initialized with the specification necessities in terms of ordinary technical specifications along side various necessities that lay hidden from the market. It is observed that the pressure vessel parts selected on the basis of accessible ASME standards and therefore the manufactures also follow the ASME standards whereas for producing the parts.(sumit V. Dubal, S. Y. Gajjal, V. G. Patil). The structure is to be designed, analyzed, fabricated and checked as per ASME. By knowing these stresses, it is possible to work out that pressure vessel is intended for internal pressure alone and to style structurally adequate and economical stiffening for vessel that need it. (Apurva R. Pendbhaje, Mahesh Gaikwad) This International Journal of Engineering Science and Computing, June

2 technical paper presents design, and analysis of pressure vessel. In this we can say that on the basis of available ASME standards all the pressure vessel components are selected and the manufacture also follows the ASME standards while manufacturing the components. So that leaves the designer free from designing the components. This aspect implemented design greatly reduces the development time for a new pressure vessel. (Prof. P. R. Attar) Dish end and skirt assembly is carried out by Creo Elements/ Pro-E.. Due to the excess meshing full assembly was not considered; only dish, skirt and weld joint was created in assembly. Assembly was imported in ANSYS R15. The static structure analysis was carried using given data. By using FEA method simulation were carried out and compared it with allowable code values. Project overview: The whole of the pressure vessel weight is supported by lug of the vessel. So it is necessary that the lug on which pressure vessel rests has good strength to withstand all loads acting on it. Poor strength properties limit the life expectancy[1]. In this paper, we are going to work over Pressure vessel lug supports. With 3D drawing, dimensions of the pressure vessel and its support will be found out. Whatever the 3D modeling will be done in CatiaV5 R19. Then Meshing will be carried out in Hypermesh and Analysis will be carried out in Ansys. After this one we will get output in terms of Stress and deformation. Redesigning the lug if stress value exceeds the critical value. Then following the same procedure for 3D modeling some dimensional changes will be done to make the support strong, meshing and analysis of the model is to be done to ensure the new design is well below the critical value[1]. Once we get the results from numerical solutions, we fabricate prototype model of the pressure vessel lug support and carry out experimental testing on it. The experimental values should be in-line with the numerical values. Tools Used: Cad Software CatiaV5R19 CAE software Hypermesh 12.0, Ansys 13. Experimental testing UTM GENERATION OF CAD MODEL: Assembly of pressure vessel consists of a vessel, lug support on the vessel is supported and a skid frame on which whole of the vessel is mounted while transportation of the vessel from one place to another. Lug support takes up all the weight of the vessel. For calculating boundary conditions we should be required dimensions for analysis. Hence, from this we can generate a CAD model which is also necessary. The 3D drawing is generated from the 2D drawing of Pressure vessel. We use the commands in CATIA of Pad, pocket, fillet, and geometrical selections in part design module for generation of 3D drawing. In this matter to get the dimensions useful for forces calculations in static loading conditions on pressure vessel. The Parametric generation of drawings is very useful. Figure: 1 Details 3-D drawing of pressure vessel Figure : 2 Detail 2-D drawing of lug support Table 1 : Technical Speication of Pressure Vessel Design Data : Design Code : ASME VIII Div. 1 Edition 2013, BS DESRIPTION UNITS VALUE Configuration N.A Horizontal Design pressure Kg/cm Design temprature o C 55 Oprating pressure Kg/cm 2 Atmospheri c Oprating temprature AMBIENT Maximum allowable working Kg/cm pressure Hydrostatic test pressure Kg/cm Pneumatic test pressure N.A N.A Frp lining vessel internal MM 2.5 Radiography Shell/head SPOT/FUL L T joint 100% Joint efficiency (shell/head) 85% / 100% Process fluid BRINE Specific gravity of fluid 1.94 Weight Empty Kgs 2400 Full Kgs Operating Kgs Surface preparation Surface Cleaning By Grit Blasting International Journal of Engineering Science and Computing, June

3 Material of Consrtuction Main Shell IS.2062 GR B Dished End IS.2062 GR B Internal attachment IS.2062 GR B Nozzel Pipe SA106 GR B Nozzel Flange SA 105 Nozzel flange nut SA 194-2H Gasket for fange Neoprene Lifting lug IS GR B Structural members IS GR B Support Lug IS GR B Grating Bolts and Nuts IS GR B Meshed Model: Figure: 5 2D meshed model of pressure vessel Meshing of Lug support: Figure: 3 CAD model of Lug support Assembly Model: Figure: 4 CAD model of pressure vessel assembly Finite Element Analysis of pressure vessel lug support: The results of pressure vessel lug support for strengthening purpose, we are discussed and analyzed by finite element analysis. FE models are used for static analysis[3]. With the help of considering the boundary conditions the FE models are used for static analysis. For Conducting the Static Simulation a generalpurpose commercial finite element code, Hyper-Mesh and Ansys is applied. Analysis: Analysis is done by selecting appropriate methods and carrying out the operations in various stages To obtain the solution analysis is done by best appropriate method and carrying out the operations in various stages. On that occasion and particularly performing various operations in software the analysis is carried out. Stage-I In this stage, for the meshing software like Hypermesh igs. file is imported. The CAD data of the pressure vessel are imported and the surfaces were created and then we can meshed. In this the best element for meshing is the tetrahedral element. Since all the dimensions of the pressure vessel are measurable. So that, static analysis is used for analysis. Figure: 6 Meshed model of lug support The Average Element size of the Lug support is 20. Type of Element- Tetra-hedral No. of nodes No. of Elements Material properties of 210 Gpa IS 2062[9]: Young s modulus Poisson s ratio 0.3 Density 7840 kg/m³ Yield strength UTS 240 MPa 350MPa Stage-II: We can apply boundary conditions after meshing is done. In this, for calculating the results of analysis these boundary conditions are mostly preferred. For getting this, here we define and apply various loads. During analysis whatever the different load steps are created which are to be applied for analysis. Here, surrounding effect has been taken into consideration while applying loads. Properties are very useful for defining the elements. The material properties like modulus of elasticity, density, Poisson s ratio, etc. are assigned to the elements. Here, we can make proper arrangements. So that particular, we can run the analysis in solver software. After the completion of the process, the model is exported to the solver. At the bottom of the lug support it is fixed and stresses and deformation under operating weight of 18650kg i.e. a force of N is applied from the top. International Journal of Engineering Science and Computing, June

4 Figure: 7 Application of load on vessel Stage-III As on we get meshed and boundary condition, we can import to the solver. After applying all parameters, run in the solver software analysis process gets started. Firstly, Software calculates the deflection with respect to the boundary conditions applied. Then after on the basis of deflection we can calculate strain. Once the strain is calculated, we can find out the modulus of elasticity. Then after we can calculate the stress values. Then the results are viewed and accordingly modifications are suggested. Whatever, the high stress regions are obtained according to that the modification carries out. If the stresses are beyond the permissible limits, then changes are such as change in thickness of the component or the addition of ribs, change in material, etc. made according to suitability. Whatever, The calculation of stress depends upon the failure theory which is most suitable for the analysis [5] This analysis displayed for stress and deformation is the: Von-mises stress for pressure vessel lug support: Figure: 9 Deformation of pressure vessel lug support Deformation of pressure vessel lug support is mm. From the stress analysis, it is clear that stress value N/mm 2 is close to the yield value. Which means the strength of the lug support must be increased in order to support the vessel. The maximum displacement value is mm which is also very less so design is not safe. So it involves increasing the strength of the support by adding a stiffener or adding material to it (by increasing the thickness of the lug). This will be an iterative method to solve the safe design. ITERATIVE METHOD TO INCREASE THE STRENGTH OF PRESSURE VESSLE LUG SUPPORT Iteration 1: Thickness of lug support increased in order of 2mm for each: CAD model: Figure: 8 Von-mises stress for pressure vessel lug support The above figure 8 shows von-mises stresses, its value is N/mm 2 which is near to yield value of 240 N/mm 2. Hence it is not safe. Deformation of pressure vessel lug support Figure:10 CAD model of pressure vessel with 2mm increased thickness. International Journal of Engineering Science and Computing, June

5 The maximum displacement is 0.22mm. Iteration 2: Thickness of lug support increased in order of 4mm for each: CAD model: Figure: 11 Meshed model of pressure vessel lug support with 2mm increased thickness No. of nodes: No. of elements: Figure:14 CAD model of pressure vessel with 4 mm increased thickness. Following are the results displayed for stress and deformation Von-mises stress: Figure: 15 Meshed model of pressure vessel lug support with 4mm increased thickness No. of nodes: No. of elements: Figure:12 von-mises stress for pressure vessel lug support Stress value of the pressure vessel is N/mm 2 which is well below the critical value. Following are the results displayed for stress and deformation Von-mises stress: Displacement: Figure:16 von-mises stress for pressure vessel lug support Figure: 13 Displacement result for pressure vessel lug support Stress value of the pressure vessel is N/mm 2 which is well below the critical value. International Journal of Engineering Science and Computing, June

6 Displacement: Figure: 17 Displacement result for pressure vessel lug support The maximum displacement is 0.17mm Iteration 3: Thickness of lug support increased in order of 6mm for each CAD model: Figure: 20 Von-mises stress for pressure vessel lug support Stress value of the pressure vessel is N/mm 2 which is well below the critical value. Hence, design is safe. Displacement: Figure: 18 CAD model of pressure vessel with 6 mm increased thickness Figure: 21 Displacement result for pressure vessel lug support Figure: 19 Meshed model of pressure vessel lug support with 6mm increased thickness No. of nodes: No. of elements: Following are the results displayed for stress and deformation Von-mises stress: Figure: 22 Displacement result for pressure vessel lug support The maximum displacement is 0.15 mm. International Journal of Engineering Science and Computing, June

7 Results: Table 2: Sr. No Stress N/mm 2 Displacement mm Existing Iteration Iteration Iteration recorded by the data acquisition system connected to the machine. Finally a graph plot as load vs deformation is obtained Experimental Observations and results of lug support: From the above table and as per the iterations we can easily say that for finite element analysis and it is observed that stresses are minimum for case depth of 6mm thickness. It is also observed that whatever the all the analysis have stress values less than their respective permissible yield stress values as per IS So the design is safe.. Further which a prototype will be fabricated and tested. Fabricated model: The fabricated model is reduced to 2.5 times the original, so as to overcome testing constraints like specimen area and lab conditions Figure: 25Graph Load V/s Displacement Figure: 23 Actual photograph of fabricated model Experimentation: The experimental investigation is performed as fabricated prototype on universal testing machine at Praj metallurgical laboratory, kothrud, Pune. Compression test has been performed on the pressure vessel lug support. The input conditions are recreated in the lab while the component is being tested. The loading and the boundary conditions are matching the practical working conditions in which the product is expected to perform. Experimental set up: Figure: 24 Experimental Testing photographs. The specimen is mounted on the testing machine and loads are gradually applied and the respective deformed readings are From above fig. 25 we can observed the max displacement for the load applied is 0.014mm Validation: The FEA results Deformation of Lug support As the fabricated model is scaled to 2.5 times, the deformation results are divided by 2.5 factor. =FEA value/2.5 =0.154/2.5 =0.0616mm International Journal of Engineering Science and Computing, June The analysis was carried out for 4 lug support and therefore for one lug support the expected deformation becomes =0.0616/4 =0.0154mm Percentage Error = (FEA - Experimental) / FEA = ( ) / = =6.49 % Hence the result is validated with a % error of approximately 6.5. Conclusion The Lug support including the pressure vessel is analysed for the given operating conditions. The Lug support is modified by different iterations and FEA analysis is carried out over every step. The best of all the modification is chosen for the fabrication. The model is fabricated and tested for the same loading conditions as that of the conventional. From results and analysis considering induction hardening effects, it is found that the pressure vessel lug support with 6mm of induction hardening have low stresses which is having to strengthen the support for withstanding the sever high loads.this can increase the life of pressure vessel lug support and reduce the cracks and failures which is beneficial to the applicant. A comparative study of FEA and Experimental results is made. From the results it can be concluded

8 that the validation of results show close resemblance with a % error of 6.5. Hence the objective is achived References: 1. Kiran D. Parmar, Kiran A. Patel, Dinesh D Mevada, Thermal Analysis For Skirt Dished End Joint Of Pressure Vessel Using Finite Element Analysis Approach, International Journal of Advanced Engineering Research and Studies, E-ISSN B.S.Thakkar, S.A.Thakkar, Design Of Pressure Vessel Using Asme Code, Section Viii, Division 1, International Journal of Advanced Engineering Research and Studies E-ISSN Sumit V. Dubal, S. Y. Gajjal, V. G. Patil, Review on Stresses in Cylindrical Pressure Vessel and its Design as per ASME Code, International Journal of Engineering Trends and Technology, Volume 11 Number 6 - May Apurva R. Pendbhaje, Mahesh Gaikwad, Nitin Deshmukh, Rajkumar Patil, Design And Analysis Of Pressure Vessel, International Journal of Innovative Research in Technology & Science, ISSN: Mahesh C. Agiwale, Prof. P. R. Attar, Analysis of Dished Head and Skirt Joint of Pressure Vessel using FEA Method, International Journal of Science Technology & Engineering Volume 2, July 2015, ISSN (online): Amit Patil, Amol Kolhe, Finite Element Analysis: Pressure Vessel With Angular Leg Supports, international journal of mechanical engineering and robotics research, ISSN , Vol. 3, No. 3, July, Sagar P. Tiwatane, Sachin S. Barve, Finite Element Analysis of Skirt to Dished junction in a Pressure Vessel, International Journal of Modern Engineering Research, Vol. 3, Issue. 4, Jul Aug, ISSN: Vincent A. Carucci, Overview of Pressure Vessel Design, Carmagen Engineering, In Code for Pressure vessel design manual International Journal of Engineering Science and Computing, June