Thermo-economic analysis of a french fries processing plant at Lambert's Bay

Potgieter, Johan (2004-12)

Thesis (MScIng)--University of Stellenbosch, 2004.

Thesis

ENGLISH ABSTRACT: In the literature study energy efficiency is discussed in general, as well as certain critical areas of importance to this study. In addition, measuring and monitoring equipment, and energy inefficiencies in steam and refrigeration systems are reviewed briefly. In the energy analysis, an energy audit strategy is discussed in general. A walkthrough audit of the plant was conducted with specific focus on visible losses in the steam, refrigeration and production line systems. An energy analysis, as discussed in Chapter 3, indicates the main energy consumers, with steam being the biggest consumer of energy. The main consumers of refrigeration energy are the cold stores, flow freezer and blast freezer. Energy consumption in the cold stores can be minimised mechanically, while refrigeration energy of the flow freezer and blast freezer can be minimised through the modification of production activity. The main consumers of steam at the processing plant are the dryers, oil fryer, blanchers and steam peeler. Improved energy savings at the dryers can be obtained through optimisation of moisture and heat transfer mechanisms, while the energy of the blanchers and steam peeler can be combined by means of heat exchangers. The transfer of waste energy by means of a finned-tube heat exchanger from the steam peeler to the blanchers was investigated. The newly installed coal boiler shows capacity for improving the quality of steam, as well as efficiency, by incorporating an economiser and separator for improving steam quality, automatic TDS control and blow-down heat recovery. The product life cycle is discussed considering future automation that could lead to energy and labour savings. Lastly the utilisation of product waste as a future research subject is discussed. A confidentiality agreement was entered into with Oceana.

AFRIKAANSE OPSOMMING: In die literatuurstudie word energie-effektiwiteit oor die algemeen bespreek, asook sekere kritieke areas wat vir die ondersoek van belang is. Hierbenewens word meettoerusting vlugtig bespreek, asook energie-oneffektiwiteite in die verkoeling- en stoomstelsels. In die energie-ontleding word ’n energie-ouditstrategie in die breë bespreek. ’n Deurstapoudit van die aanleg is uitgevoer met spesifieke fokus op sigbare verliese in die verkoelingstelsel, stoomstelsel en produksielyn. Die samestelling van energieverbruik in die aanleg word uiteengesit in Hoofstuk 3, waar dan ook aangedui word dat stoom die grootste energieverbruiker is. Die hoofverbruikers van verkoelingsenergie is die koelkamers, die deurvloei-vrieskamer en die blitsvrieskamer. By die koelkamers kan verliese meganies geminimeer word, terwyl veranderinge aan produksie-aktiwiteite energieverbruik by die deurvloei-vrieskamer en die blitsvrieskamer kan verlaag. Die hoofverbruikers van stoom by die verwerkingsaanleg is die droërs, oliebraaier, blansjeerders en stoomskiller. Energie-effektiwiteit by die droërs kan verhoog word deur vog- en warmte-oordrag optimaal te laat plaasvind deur korrekte instandhoudingsprosedures. Energieverbruik by die stoomskiller en blansjeerders kan deur middel van warmteruilers gekombineer word. ’n Ondersoek na die energie-integrasie van die stoomskiller en die blansjeerders is dan ook uitgevoer. Die pas geïnstalleerde steenkoolketel toon ruimte vir die verhoging van energie-effektiwiteit deur die daarstel van ’n ekonomiseerder – ’n skeier wat die gehalte van die stoom verbeter, outomatiese TDS-beheer en afblaasherwinning. Die produk se lewensiklus word bespreek ten einde toekomstige outomatisering te motiveer in terme van energie- en arbeideffektiwiteit, asook die uitskakeling van onnodige blootstelling van die produk aan omgewingstemperature. Laastens word die herwinning van afvalstowwe as ’n toekomstige navorsingsprojek bespreek. ’n Vertroulikheidsooreenkoms is met Oceana gesluit en word eerbiedig.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/16412
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