Kurzfassung: 〈 p 〉 〈 strong 〉 Engineering of solar collector and LPG-burner for curing Virginia tobacco 〈 /strong 〉 〈 /p 〉 〈 p 〉 Indonesia produces 30 tones of Hue cured tobacco every year. Curing Virginia tobacco needs I 29 I kerosene per I kg cured leaves, thus lo process 30 tones cured leaves, it needs 38.7 liter kerosene with a value ol Rp 1 5.5 billion per year Kerosene as a source of energy is used for house hold in Ihe village and it is highly subsidized by the government. For such industries as tobacco processing other sources of energy are available, including gas oil, diesel oil and fuel oil, solar energy, coal, and liquid petroleum gas This study was aimed at designing solar collector and LPG buner suitable lor Virginia tobacco flue curing. Tobacco leaves were cured in a curing barn with LPG as a fuel, while the solar collector was installed on Ihe roof of Ihe barn. The size of the curing barn was 4 m x 4 m x 7 m with a capacity of iwo tones fresh leaves. The LPG-burner used was BA'I'/Baliltas-I, with was specially designed for lobacco curing barn ('nring method followed Ihe standard method practiced by farmers The experiment was conducted al IT Sadhana Arif Nusa. Has! Lombok. NTR from Angus! lo September 1997 The rcsull of experiment was evaluated holh from technical and economical aspects. The used of LPG combined with solar collector as the source of energy could reach Ihe required temperatures (J0-70°(.) during curing phases LPG consumption was 0.86 kg/ kg cured leaves, and solar energy contributed 6.48% of total energy required for curing process From economical view, the used of LPG and solar energy was not profitable. This was mainly due to Ihe high prices of LPG (Rp I 000 /kg) LPG-lank (Rp 1 600 000/unit) and roof- solar collector (Rp I 500 000 per unit). 〈 /p 〉

Kurzfassung: 〈 p 〉 〈 strong 〉 The use of diesel-oil and solar energy as an alternative energyfor Virginia tobacco curing 〈 /strong 〉 〈 /p 〉 〈 p 〉 The use of diesel oil and solar energy in the curing on Virginia tobacco was studied in two steps, i.e., the laboratory experiment al Ihe Research Institute for Tobacco and fiber Crop Malang and ield experiment (economic scale) in East Lombok, NIB. The study was conducted from July to September 1998. The laboratory experiment was aimed at evaluating the effect of diesel oil on (he aroma of cured leaves. Results showed that there was no Strange aroma of Ihe cured-leaves, as the effect of diesel-oil burning Ihe experiment using economic scale curing-bani indicated that the diesel-oil consumption was 0 76 l/kg krosok and if flat-plate solar collector was constructed as a roof, consumption decreased 7.84% which was equal with 0.06 l/kg krosok or 2.574 kJ/kg krosok. Economic analyses showed that using diesel-oil and flat-plate solar collector as a energy source gave a proit chance and an ability to pay the 18%/year of the capital interest, with B/C ratio -1.74, NPV=Rp 45 340 131, and IRR-52 93%. If only diesel-oil was used, it gave a lower proit with B/C ratio=l.77, NPV=Rp 46 425 215. and IRR=53.19%. The increase in the diesel-oil price up to Rp I 500/1 would give a profit chance and an ability lo pay the capital interest, with the B/C ratio = 1.487 and 1 .490. with IRR = 52.67% dan 52 99%, for curing the tobacco leaves with diesel-oil and solar collector, and with diesel-oil only, respectively. 〈 /p 〉

Kurzfassung: 〈 p 〉 Oven portabel-horisontal (4m x 8m x 4m) untuk pengovenan daun tembakau Virginia menjadi krosok fc (flue-cured) telah direkayasa di Balai Penelitian Tanaman Tembakau dan Serat, Malang, Indonesia. Konstruksi oven terdiri alas komponen dinding oven berisolasi (80cm x 200cm), kerangka dari besi siku dan bcsi U, kolektor surya datar (solar flat- collector) yang dipasang pada atap oven. Sistem pcmanas kompor Bros dengan pemanasan tidak langsung. Pengujian dilakukan pada bulan Agustus sampai dengan Oktober 2002 di Lombok Timur, Nusa Tenggara Barat. Model oven portabel-horisontal ini diharapkan dapat menghasilkan suhu niang oven yang seragam sehingga dapat digunakan untuk mengoven daun tembakau yang persentase masak optimalnya tinggi (90- 95%), hemat bahan bakar, dapat dipasang mendekati areal tanaman sehingga hemat ongkos angkut dan dapat menekan kerusakan pasca panen. Hasil penelitian menunjukkan rata-rata selisih suhu ruang atas dan ruang bawah, serta ruang sebclah kanan dan sebelah kiri, masing-masing 2.53°C dan 2.30°C sedangkan selisih kelembaban udara pada posisi yang sama masing-masing hanya 4.55% dan 3.64%. Kadar gula krosok yang dihasilkan berkisar antara 17.19-19.47% dan nikotin 3.16-3.73%. Konsumsi minyak tanah 1.09 l/kg krosok atau 1.16 l/kg krosok jika tanpa kolektor surya dan hanya 40.92% dibanding oven biasa yang memeriukan 2.39-2.80 l/kg krosok. Kolektor surya datar menyumbang 952 625 kJ setara 28.24 I minyak tanah atau 5.80% dari konsumsi minyak tanah, meskipun alat ini memeriukan 17.16% dari total investasi oven. Panas yang hilang melalui dinding karena konduksi hanya mencapai 3.57%, lebih rendah dibanding kehilangan panas pada dinding bata yang mencapai 12.7% - 16.0%. Hasil grading krosok menghasilkan harga jual rata-rata Rp. 12.275/kg kosok, sedangkan hasil analisis ekonomi menunjukkan rasio BC = 1.29; NPV = Rp. 41 962 590 dan IRR = 51.83% atau masih membei peluang keuntungan dan pengembalian kredit. Hasil perhitungan simulasi jika digunakan oven horisontal sederhana dengan harga Rp. 8 000 000 tiap unit, harga krosok Rp. 10 000, Rp. 12 500, dan Rp. 15 000 tiap kg dan harga minyak tanah Rp. 1 000, Rp. I 250 dan Rp. I 500 tiap liter masih memberi indikasi peluang keuntungan dan pengembalian kredit. Konstruksi oven akan lebih sederhana jika digunakan kerangka kayu dan tanpa kolektor surya. 〈 /p 〉 〈 p 〉 Kata kunci : Nicotiana tabacum, L, tembakau, prosesing, oven, portabel- horisontal, kolektor surya, analisis energi, mutu krosok, aspek ekonomi 〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉 〈 strong 〉 ABSTRACT 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 Engineering of horizontal-potabel curing-barn of Virgi¬ nia tobacco curing 〈 /strong 〉 〈 br / 〉 〈 br / 〉 Engineeing of the horizontal-portable curing-barn (4m x 8m x 4m) of Virginia tobacco curing lo produce Virginia fc (flue-cured) tobacco conducted in Indonesian Tobacco and Fibers Crops Research Institute, Malang, Indonesia. The curing-bam construction consisted of portable isolation wall, metal frame from L and U iron-bar and flat solar collector which was installed in curing-bam roof. Bros buner and air indirect heating system were used. This curing-bam was tested in East Lombok, West Nusa Tenggara on virgina tobacco harvested in August to October 2002. This horizontal-portable curing-bam was expected to be able to 〈 br / 〉 〈 br / 〉 96 〈 br / 〉 〈 br / 〉 produce the homogen temperature and humidity in all space of the curing- bam so that it is suitable for curing the harvesting tobacco leaves which high percentage of mature leaves (90-95%), fuel efficienct and liable to be constructed near tobacco plant area, so that it can decrease the transpotation cost and postharvest damage. The result of the research showed that there were significant difference between above-space and lower-space, let-space and right-space, even it was only 2.53°C and 2.30°C, respectively. The same position for air humidity, 4.55% and 3.64%, respectivelly. Kerosene fuel consumption 1.09 I each kg cured- leaves or 1.16 I each kg cured leaves if without lat solar collector, lower than farmers conventional curing-bam which consumpt 2.39-2.80 I each kg cured-leaves. Flat solar-collector contributed 952 625 Id only or 5.80% of kerosene consumption or equal lo 28.24 I kerosene, even though this equipment needed 17.16% of total curing-bam in vestal ion Heat conduction lost through the portable wall only 3.57%, lower than brickwall conventional curing-bam which reach 12.7-16.0%. Result of the cured-leaves grading gave the average price Rp 12 275,- each kg cured- leaves and economic analysis showed that BC-ratio-1.29, NPV-41 962 590 and IRR=51.83% or still gave the profit chance and ability to pay the capital interest. Result of simulate calculation by simple construction curing-bam, Rp. 8 000 000 price each unit, still gave BC-ratio above one percent. This indicated the profit chance and ability to pay the capital interest. In this simulate calculation three price of cured-leaves and kerosene was used, as followed Rp. 10 000, Rp. 12 500, and Rp. 15 000 each kg cured leaves, and Rp. I 000, Rp. 1 250 and Rp. I 500 each liter of kerosene, respectivelly. The construction of the curing-bam will be simpler if using wood frame and without lat solar collector. 〈 /p 〉 〈 p 〉 Key words : Nicotiana tabacum, L., tobacco, processing, oven, horizontal- portable curing-bam, lat solar-collector, energy analysis, cured-leaves grade, economical-aspect 〈 /p 〉

Kurzfassung: 〈 p 〉 Pcrekayasaan instalasi pemanfaatan udara panas buang pada pengolahan daun tembakau Virginia menjadi krosok fc (flue-cured) telah dilaksanakan di Balai Penelitian lanaman lembakau dan Serat, Malang, Jawa Timur. Pengujian alal dilakukan di lombok Timur, Nusa Tcnggara Barat, pada musim panen antara bulan Agustus sampai dengan Oktober 2000 di sentra produksi tembakau Virginia Hasil penelitian ini diharapkan dapat mendukung efisiensi penggunaan biaya bahan bakar sekaligus mengurangi subsidi bahan bakar minyak dari Pemerintah Konstruksi instalasi pemanfaatan udara panas buang terdii atas pipa penghubung (d~ 15.24 cm) dua oven dan blower 0 75 TK untuk mcngalirkan udara panas buang dari oven pertama ke oven kedua. Kapasitas oven pertama yang digunakan 3 547 kg, sedangkan oven kedua 2 617 kg daun lembakau. Hasil penelitian menunjukkan bahwa. pemasangan instalasi udara panas buang dapat menekan konsumsi bahan bakar oven kedua 12 39% yaitu dari 1 352 liter minyak tanah tiap kg krosok menjadi 1.141 liter tiap kg krosok. Analisis ekonomi pada harga minyak tanah Rp 700/1 penggunaan alat tersebut belum memberikan keuntungan yang bcrati karena nilai rasio BC ■ 1.29. NPV ■ Rp 99 835 885 dan IRR - 52 73%, dibandingkan tidak memasang instalasi tersebut dengan nilai rasio BC 1.29, NPV Rp 98 547 176, dan IRR 52 78%. Namun bila harga minyak tanah Rp. 1 000/1 maka pemasangan instalasi udara panas buang membeikan nilai rasio BC 1.25, NPV Rp. 88 246 683 dan IRR -52 58%. lebih baik dibanding tidak memasang instalasi tersebut (rasio BC 1 24. NPV Rp. 85 977 099 dan IRR - 52 63%) Peluang keuntungan rclatif makin besar jika harga minyak lanah makin linggi. Keuntungan lain pemasangan instalasi ini adalah menekan subsidi bahan bakar minyak. 〈 /p 〉 〈 p 〉 Kata kunci : Nicotiana tabacum 1. , oven, instalasi udara, panas buang, mutu, aspek ekonomi 〈 /p 〉 〈 p 〉   〈 /p 〉 〈 p 〉 〈 strong 〉 ABSTRACT 〈 /strong 〉 〈 /p 〉 〈 p 〉 〈 strong 〉 Utilization of waste heat-air installation in Virginia tobacco curing 〈 /strong 〉 〈 /p 〉 〈 p 〉 Installation of me waste hcal-air utilization in Virginia tobacco curing to produce flue-cured tobacco has been conducted in Indonesian Tobacco and fiber Crops Research Institute. Malang, Indonesia. The equipment test was taken place in Virginia tobacco production centre. East lombok. West Nusa Tcnggara Province on harvesting-time between August and October 2000 Ihe result of the research was expected to suppot fuel efficiency, and decrease the government fuel-oil subsidiary. Construction of Ihe waste hcat- air installation consisted of connecting-pipe (d 15.24 cm) between two eunng-bams. and 0 75 HP blower for blowing the waste heat-air to the second cunng-barn The capacity of the irst curing-barn was 3 547 kg tobacco leaves and second curing-bam was 2 617 kg tobacco leaves. The results of the experiment showed that the installation of the waste hea(-air equipment could reduce 12.39% of fuel consumption of second curing-bam, from 1.352 I kerosene per kg to 1 141 I kerosene per kg of the cured leaves The economic analysis of the equipment al kerosene price Rp 700/1 was that equipment did nol give meaning-full benefit, because the value of B'C ratio 1.29, NPV Rp 99 835 885 and IRR 52.73%, compared to those without waste heal air installation, with BC ratio 1 29, NPV Rp. 98 547 176 and IRR 52.78%. Nevertheless al Rp I 000 1 kerosene price the installation of waste heal-air equipment gave the B'C ratio -1 25. NPV ■ Rp. 88 835 885 and IRR 52 58%, was better than those without equipment installation (BC ratio I 24. NPV Rp. 85 977 099 and IRR' 52 63%). Relative beneit chance would be beter if there was higher kerosene price. Ihe other benefit from the installation of Ihe equipment was to reduce government fuel subsidiary. 〈 /p 〉 〈 p 〉 Key words Nicotiana tabacum I... curing-bam. waste heat-air, installation, quality, economic aspect 〈 /p 〉