ERU - 1995

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Browsing ERU - 1995 by Author "De Alwis, AAP"

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    Biomethanation studies at university of moratuwa
    (Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 1995-03) sivapathasundaram, R; Wanigasekara, N; De Alwis, AAP; Dias, WPS
    Biogas generation or Biomethanation offers a viable option in simultaneous solid waste management and energy generation. The technology is quite well developed and is not only confined to developing countries as commonly perceived by many. However, the scale of practice and the objectives in developing and developed countries vary. A biogas program has been active in Sri Lanka as well, though this has not achieved the popularity or acceptance as in countries like China, India and Nepal. The Sri Lankan program however, has been successful in giving rise to a new design which is termed the Dry Batch digester. The work has been mainly done by the National Engineering Research and Design Centre (NERD). The concept is different to the two main types due to the use of an essentially ‘dry* mixture of organic waste, and the batch type operation. In urban areas biomass such as straw or animal wastes such as cowdung cannot be found in such quantities to have biogas systems of continuous nature. The NERD version of batch type could be effectively employed in institutions where organic wastes are generated, or to employ solid wastes such as market garbage. Their biomethanation kinetics favour the batch approach. The objective of the research program undertaken by the Department of Chemical Engineering was to do detailed evaluation of scientific, technological and social aspects of biogas systems as a means of pollution prevention with simultaneous energy generation. Laboratory studies have been done on various industrial waste streams ranging from food processing wastes to textile industry effluents which arc quite toxic to micro-organisms in general. This paper introduces the basic concepts and some of the methodologies followed by the research team. To support dissemination of biogas technology, a pictorial step-bystep guide detailing out all stages involved in the building and operation of a digester and a gas holder system has been prepared as part of this work.
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    Computer integration for sri lankan industries - a review
    (Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 1995-03) De Silva, S; Wijesoma, WS; De Alwis, AAP; Dias, WPS
    production and manufacturing industries employ obsolete methodologies. However with the advent of personal computers in the early 1980's the user community enlarged very rapidly. The telecommunication infrastructure has been enhanced in the last five years allowing private networks such as cellular methodology for computer interconnectivity. A good example of optimum use of these facilities is that of local private banks that open many branches on the Uni Bank principle using centralized host computer directly connected to the branches as well as ATMs at strategic locations in the city. Moreover the printing and publishing industry seems to have absorbed new computer based technology successfully where operations carried out are predominantly image acquisition, image setting and printing. This paper is an outcome of an ongoing survey carried out mainly to assess the areas of application and extent of computerization in the Industrial Sectors in Sri Lanka.
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    Ohmic heating for tropical food processing : f experimental studies on heating and nutrition effects.
    (Engineering Research Unit, Faculty of Engiennring, University of Moratuwa, 1995-03) Shantha, W; De Alwis, AAP; Edirisinghe, R; Dias, WPS
    Ohmic heating of foods is a novel food processing operation which directly utilizes electricity as the major heat source, and can be termed as an electroheat technique. The heat effect is achieved by passing an electric current through the product to be heated, the passage of current through the material obeys Ohm's law and depending upon the resistance offered by the media, heat is generated. If the objective is only heat generation, it matters little whether DC or AC is used, however, the use of AC can eliminate electrolysis. Electrolysis of food is obviously undesirable and so ohmic heaters are operated using an AC supply. Little work has been carried out with regard to this process and that it is only recently research has been started in UK, USA and France. Ohmic heating offers several important advantages over conventional food processing. It is possible to apply the technique to process many types of food materials. Some of these are beverage, dairy and vegetable products etc. Results of studies conducted on heating profiles and nutrient retention are presented. Initially a detailed picture of current fruits and vegetable production and associated problems are presented as this provides the essential back drop to this study. Basic nutrition studies have revealed some new information. Nutrition studies conducted has been for the first time and is of major importance.