Konstruktion av stationär komprimator

This Master’s Thesis, under the Division of Machine Design at Lund Institute of Technology, was conducted at Presona AB located in Tomelilla, Sweden during the first half of 2006. Presona AB is a leading manufacturer of equipment for handling and compression of waste. The object of the thesis is to reduce the manufacturing cost of Presona’s heavy duty stationary compactor. This is acquired by redesign of the product. Presona’s existing stationary compactor is a robust product which compresses the waste by means of a hydraulic cylinder positioned centrally in the compactor. The cylinder is dimensioned to attain a press force of 30 metric tons. The compactor consists of four major parts; the frame, the press plate, the hydraulic system and the electric system. The focus of the Master’s Thesis has been put on redesign of the frame and the press plate which have been analyzed in ANSYS Workbench [7] in order to identify redundant and over dimensioned parts and components. The thesis’ objective was to reduce the compactor’s manufacturing cost by 40 per cent. A number of primary product concepts were developed, analyzed and evaluated during the concept generation part of the project. Out of these concepts four were judged good enough to be further developed during the second part of the concept generation. These were evaluated and graded according to the methodology in Ulrich and Eppinger’s book Product Design and Development [4]. The result of the evaluation was that Presona’s current concept is to be further developed during the concept development phase. The frame and the press plate were continuously further developed and redesigned after discussions within the group and with representatives from Presona and after stress analyses in ANSYS Workbench conducted by Johannes Lind and Rasmus Juhlin [7]. During the redesign of the frame and the press plate the accessibility during service was taken into consideration and they were designed to be easy to manufacture and assemble. The final design of the compactor is made with the new designed frame and press plate together with the current hydraulic- and electric systems. Both the frame and the press plate have been lightened and the total weight of the compactor has been reduced by almost 23 per cent. Both parts are built by fewer parts than before, they are designed for manufacture and the need of welding has been reduced. The stress analyses of the frame and the press plate indicates that they will stand normal maximal press force and the uneven loads that have been analyzed. In order to further reduce the manufacturing cost of the compactor the hydraulic system and the electric system should be changed. Through minor changes in the compactor’s performance it is possible to exchange the custom-made cylinder of today to a standardized cylinder. The electric system should be PLC-controlled instead of being relay controlled as it is today. Our recommendation to Presona is to investigate these suggested changes and our estimation is that the object of the thesis is reachable if they are performed.