Structured packing in air distillation

An economic analysis has been performed to establish when it is advantageous to use structured packing in air separation plant. A model of a low pressure cycle was developed to calculate the power saved when packing is used, and cost models were developed for the columns and cold box. The rate of return was calculated on the extra investment required for a packed plant based on the annual power saving. Structured packing was found to be economic only in larger plants, where economies of scale mean that the increased capital cost becomes less significant compared with the power saved. It was also found that different sized plants favour different packings. The analysis identified that the packing variable with the biggest impact on the economic balance was the efficiency and that increasing the efficiency of current packings could enhance their balance in air distillation. A new packing was therefore developed to have a higher efficiency than conventional ones. The vapour phase resistance was targeted for reduction, since most packing models predict this to be dominant. The final shape was chosen as the easiest and most economic to make. It has converging and diverging channels and was manufactured in two specific areas and with two block heights by Tianjin University Packing Factory. A 0.3 m diameter distillation column test rig was designed, built and commissioned with the standard Sulzer Mellapak 500YW. It was then used to test the new packing alongside some standard ones. Because the packings had different specific areas, correlations of published results were developed to allow a true comparison to be made. The test results show that, unexpectedly, the packings with 0.1 m high blocks have an efficiency about 8% greater than the standard 0.2 m blocks. The new shape as implemented in the 350Y packing shows an additional 7% greater efficiency, so it is 15% better than a standard packing with the same area. It has a better efficiency than the Mellapak 500YW and the higher capacity associated with its lower area. The new 500Y did not show a significant advantage.

Capability development in Chinese manufacturing:a quasi-biotic perspective of knowledge evolution

A quasi-biotic model of knowledge evolution has been applied to manufacturing technology capability development which includes product design and development and manufacturing process/workflow improvement. The concepts of “knowledge genes” and “knowledge body” are introduced to explain the evolution of technological capability. It is shown that knowledge development within the enterprise happens as a result of interactions between an enterprise’s internal knowledge and that acquired from external sources catalysed by: (a) internal mechanisms, recources and incentives, and (b) actions and policies of external agencies. A matrix specifying factors contributing to knowledge development and types of manufacturing capabilities (product design, equipment development or use, and workflow) is developed to explain technological knowledge development. The case studies of Tianjin Pipe Corporation (TPCO) and Tianjin Tianduan Press Co. are presented to illustrate the application of the matrix.

International technology transfer and development of capabilities in Chinese state-owned manufacturing enterprises:lessons from 20 years of case research

Technological capabilities in Chinese manufacturing have been transformed in the last three decades. However, the extent to which domestic market oriented state owned enterprises (SOEs) have developed their capabilities is not clear. Six SOEs in the automotive, steel and machine tools sectors in Beijing and Tianjin have been studied since the mid-1990s to assess the capability levels attained and the role of external sources and internal efforts in developing them. Aided by government policies, acquisition of technology and their own efforts, the case study companies appear to be broadly following the East Asian late industrialisation model. All six enterprises demonstrate competences in operating established technology, managing investment and making product and process improvements. The evidence suggests that companies without foreign joint venture (JV) collaborations have made more progress in this respect.

Editorial

This time of year we look back at the year that has passed and make plans for the next year. I like to reflect on things that I have learnt and people that I have met, especially those who facilitated that learning. In 2009 I went to various conferences, The BCLA conference in Manchester, The Romanian Optical Society meeting in Brasov, Transylvania (where the university is actually on Vlad Tepes Street), The European Council for Optometry and Optics (ECOO) in Brno, Czech Republic, The American Academy of Optometry (AAO) in Orlando USA, The International Association of Contact Lens Educators (IACLE) meeting in Tianjin China and finally The Vereinigung Deutscher Contactlinsen-Spezialisten (VDCO) meeting in Jena. All were interesting places and thoroughly all were enjoyable conferences with their own highlights but I wanted to focus on Jena and one person I met there and his inspirational search for knowledge and the contributions he made in the field of contact lenses. Jena itself is a fascinating place and should be on the ‘must visit’ list of anyone involved in eye care. It is the birth place of Carl Zeiss of course and where he started his company. It is also the birth place of Ernst Abbe (physicist and optometrist and expert lens maker), and Otto Schott (chemist and technologist who made high quality glass. There are many road signs bearing witness to these famous pioneers. The optical museum is worth spending a few hours looking around too. I was invited to speak at the VDCO at the kind invitation from colleagues at the Jena School of Optometry, Professor Wolfgang Sickenberger and Professor Sebastian Marx. At this meeting I met 87-year-old Willi KAUE who was being awarded the Adolf Wilhelm Müller-Welt prize by the VDCO for contribution to contact lenses over his 60-year career. At the age of 15 Willi Kaue took up an apprenticeship to become an Optician in Germany in 1937. At this time he first heard about the scleral glass lenses made by the Carl Zeiss Company in Jena. This started his lifelong fascination which was to become his passion but not yet his career. During the war he was enlisted into military service but immediately after was back to his former career. In 1950 Willi corrected his own 3.5 dioptres of myopia with a plastic scleral lens. His fascination strengthened as for the first time he himself could experience a wider field of view than his spectacles gave him, less aberrations and less retinal minification. He also appreciated the fact that contact lenses did not cause pressure on the nose or ears and did not slide down his nose plus remained optically centred with his eye movements. He decided that form now on he would make fitting contact lenses his career. He travelled to London to learn more about contact lenses and how to fit them but initially did not find many willing teachers and to start with became largely self-taught. He wanted to know how to make scleral lenses. So far he only knew that pulverized polymethyl methacrylate (PMMA) was pressed and moulded. In 1951 he met Berlin optician Otto Marzock. He made his only scleral lenses from using military PMMA windshields. His process involved lathe cutting the lenses and resulted in lenses that were thinner than moulded ones. Willi developed a manufacturing method, using a rotary diamond drill, starting form the outer edge and towards the centre at a constant cut speed. This enabled him to make more reproducible lenses and in less time. His enthusiasm in the field was clear from the travels he made in the pursuit of advancement - travelling around Europe, South America, North America and Asia. In 1963 he visited George Nissel in Hemel Hempstead, England. Constantly thriving towards innovations Willi came across the new Naturalens from the USA made from HEMA at a congress in Marseille in 1969. Amongst his contributions to the field, was his own technique of fitting ocular prosthetics, using an alginate impression of the orbit. I was fortunate enough to have dinner with Willi Kaue and learnt more about his fascinating career through the patient interpreting skills of Hilmar Bussacker (the 2008 winner of the same award and the 2007 winner of the European Federation of the Contact Lens and IOL Industries Award). I look forward to 2010 with eager anticipation as to what I may learn and who I might meet!!! Copyright © 2009 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.