Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Abstract:
Paper production has become a very important aspect of daily life. Presently, most of the paper being used in Nigeria today is imported. The Pulp Digester has been designed and fabricated to enhance the production of paper locally, thereby reducing losses to the Nigerian economy due to foreign exchange. This paper describes an improved directly heated, batch pulp digester built for laboratory use. It consists of the pulping vessel and lid, electrical components and control units, heaters, pressure gauge and timer and the vessel stand. The electrical components maintain precise controls over pulping conditions (time, temperature and pressure) for different pulp activities (pre-steaming, liquor impregnation and cooking). The geometry of the digester, including a 20 litres cylindrical vessel of 10mm thickness securely fixed with heaters and lagged with 50mm thickness of glass fibre and sealed up with a galvanized plate coated with silver colour and a number of peripheral measuring links connected to the lid. The designed capacity is 8kg/day while the maximum pulping efficiency is 62% at 180OC and 6 bar and the optimum liquor concentration used are 50% NaOH, 25% Na2S of wood chip mass for a period of 4hrs and the total cost of the equipment is $173.

Keywords: pulp digester, liquor concentration, design, efficiency, capacity.

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