Design of Material Removal Arrangement Required During Various Stages of Pressure Vessel Manufacturing

Abstract

Grinding is one of the major processes in any manufacturing industry which plays vital role in production cycle and quality of the product. In manufacturing of pressure vessel, plates are rolled and joined by longitudinal weld to form shell and then different shells are joined by circumferential weld and longitudinal weld to form the vessel. There are some stages in pressure vessel manufacturing process in which grinding is necessary. There are requirement for weld edge preparation, Surface finish for some NDT test and for back gouging or chip back of welding. Manual Grinding is always an option in grinding but it is dangerous for worker and also at some stages it is not accurate and it takes more time. Another option is to buy costly grinding machines. Therefore it is required to design material removal arrangement which will be beneficial for the company. Present work contains design of Grinding head and design of column boom for that grinding head.. Whole arrangement is column beam type arrangement with several motions, so that all grinding point can be achieved by grinding head. The grinding machine has eight degree of freedom. It is possible to achieve all the necessary point for grinding operation with the help of these motions. Grinding head has vertical and horizontal motion with the help of pneumatic force. Vertical motion is for applying pressure required for grinding. The movable grinding head is mounted on slewing ring. Grinding head with slewing ring can be rotated using slew drive and the complete arrangement is mounted at the boom end with the help of linear guide ways and ball screw. Boom can slide on slide ways provided on column with the help of carriage assembly. Column has slewing ring at the base with motor and gear box for rotation. Operator can adjust pneumatic force by pressure regulator. For each Degree of freedom, components are designed and available components are selected from the manufacturer company's catalogue. The structural parts are designed as per requirements and analysis is carried out in software NX 7.5.