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All Journal International Journal of Renewable Energy Development Jurnal Keteknikan Pertanian Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan (Journal of Natural Resources and Environmental Management) agriTECH Agrokreatif Jurnal Ilmiah Pengabdian kepada Masyarakat Warta IHP (Warta Industri Hasil Pertanian) Jurnal Ilmiah Rekayasa Pertanian dan Biosistem Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Jurnal Teknik Mesin Indonesia International Journal of Renewable Energy Development
Nelwan, Leopold Oscar
Departemen Teknik Mesin Dan Biosistem, Fakultas Teknologi Pertanian, Institut Pertanian Bogor, Kampus IPB Dramaga, Bogor, 16680
Aerospace Engineering Agriculture, Biological Sciences & Forestry Automotive Engineering Chemistry Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Mechanical Engineering

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Sebaran Suhu pada Sistem Hidroponik Substrat dengan Pendinginan Terbatas Daerah Perakaran Nurul Choerunnisa; Herry Suhardiyanto; Leopold Oscar Nelwan
Jurnal Keteknikan Pertanian Vol. 6 No. 3 (2018): JURNAL KETEKNIKAN PERTANIAN
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1664.512 KB) | DOI: 10.19028/jtep.06.3.233-240

Abstract

AbstractHigh environment temperature in humid tropical lowland can cause vary physiological problems for plants. Zone cooling system for substrate hydroponics was built to maintain root zone temperature of the plants. The objective of this research was to predict temperature distribution in substrate hydroponicssystem root zone with root zone cooling which is important parameter in evaluating root zone cooling system. The distribution of root zone temperature was simulated using computational fluid dynamics (CFD) approach. The simulation result showed uniformed temperature distribution in the planting medium for hydroponic substrate with minimum, maximum, and average temperature of 12.60oC, 39.90oC, and32.00oC, respectivelly. The comparison between simulated and measured root zone temperature using linear regression analysis resulted in gradient value of 1.01, coefficient of intercept value of 0.39, and coefficient of determination value of 0.98. Hence, the developed simulation model with CFD approach can be used to predict root zone temperature of substrate hydroponics system with root zone cooling.AbstrakSuhu lingkungan yang tinggi di dataran rendah tropika basah dapat mengakibatkan berbagai masalah fisiologis pada tanaman. Sistem pendinginan terbatas untuk hidroponik substrat telah dibangun untuk menjaga suhu daerah perakaran tanaman. Tujuan dari penelitian ini adalah untuk memprediksi sebaran suhu daerah perakaran pada sistem hidroponik substrat dengan pendinginan terbatas daerah perakaran yang merupakan parameter penting dalam mengevaluasi sistem pendinginan terbatas daerah perakaran. Sebaran suhu daerah perakaran tanaman disimulasikan dengan menggunakan pendekatan computational fluid dynamics (CFD). Hasil simulasi menunjukkan sebaran suhu media tanam yang tidak seragam dengan suhu minimum, maksimum, dan rata-rata secara berurutan sebesar 12.60oC, 39.90oC, dan 32.00oC. Perbandingan antara suhu daerah perakaran hasil simulasi dan pengukuran dengan analisis regresi linear menghasilkan nilai gradien sebesar 1.01, nilai koefisien intersep sebesar 0.39, dan koefisien determinasi sebesar 0.98. Oleh karena itu, model simulasi dengan pendekatan CFD yang telah dikembangkan dapat digunakan untuk memprediksi sebaran suhu daerah perakaran sistem hidroponik substrat dengan pendinginan terbatas daerah perakaran.
Desain dan Uji Kinerja Alat pengering Hybrid Dengan Efek Cerobong Tipe Tumpukan untuk Pengeringan Biji Kopi Arabika Irwansyah Irwansyah; Leopold Oscar Nelwan; Dyah Wulandani
Jurnal Keteknikan Pertanian Vol. 7 No. 3 (2019): JURNAL KETEKNIKAN PERTANIAN
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1816.889 KB) | DOI: 10.19028/jtep.07.3.163-170

Abstract

Artificial drying method for arabica coffee beans requires a large consumption of electrical energy. Electricity is needed to rotate the blower which functions to circulate hot air to the dryer so that it can evaporate some of the water contained in the coffee beans. Most of the arabica coffee producing areas in Aceh province have not been reached by the electricity network so the use of artificial dryers cannot be used. To overcome this obstacle, the air flow circulation system with chimney effect can be used to drain dry air. The aim of this research is to design a chimney effect hybrid dryer which is heat source from solar and biomass energy, to test the performance of the dryer and compare it with the sun drying method. Parameters observed were temperature, moisture content and specific energy consumption of solar radiation and biomass. Dryer capacity is 5 kg of arabica coffee beans. The results showed that the chimney effect hybrid dryer can be used to dry 5 kg of coffee beans. The drying show that drying temperature on the dryer chamber ranged between 37.3-60.9°C. To reduce the moisture content of coffee beans from 52.5 to 12.8% bb, it was take 16-17 hours, while the sun drying method takes up to 46 hours (6 days). The total specific energy consumption of hybrid dryer was 57.1 MJ/kg of water vapor, while the specific energy consumption of the drying method was 59.4 MJ/kg of water vapor.
Analisis Teknis Kolektor Surya Tipe Pelat Datar Glazed dan Unglazed pada Berbagai Laju Aliran Debit dan Suhu Inlet Rustam Efendi; Leopold Oscar Nelwan; Dyah Wulandani
Jurnal Keteknikan Pertanian Vol. 7 No. 1 (2019): JURNAL KETEKNIKAN PERTANIAN
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1241.32 KB) | DOI: 10.19028/jtep.07.1.113-120

Abstract

AbstractResearches on glazed and unglazed flat plate type solar collectors have been carried out previously for the purposes of water heaters and air heaters. However, studies related to the comparison of glazed and unglazed solar collectors especially to heat air suitable for rice drying have not been carried out yet. The purpose of this study was to compare the performance of glazed and unglazed solar collectors in the same weather conditions to heating the water for various water flow rates and inlet temperatures. The research approach used in this study is the experimental approach. Parameters measured include inlet temperature, outlet temperature, ambient temperature, flow rate, wind speed, and irradiation. The collector test uses four collectors (two unglazed and two glazed). The test results show that the highest efficiency is shown bythe glazed collectors, which is 63%, while the unglazed collector efficiency is 54%. Both of the efficiencies occured at a flow rate of 3 liters/minute, inlet temperature of 40°C and at noon time. The cost per watt (useful energy) of glazed flat plate solar collector was less than unglazed flat plate solar collector.AbstrakSalah satu cara untuk memanfaatkan energi surya adalah dengan menggunakan kolektor surya sebagai alat untuk mengubah energi matahari menjadi energi panas. Penelitian tentang kolektor surya tipe plat datar glazed dan unglazed telah dilakukan sebelumnya untuk keperluan pemanas air dan pemanas udara. Namun, studi yang terkait dengan kombinasi kolektor surya glazed dan unglazed khususnya yang akan digunakan untuk pemanasan udara yang sesuai dengan gabah belum dilakukan. Tujuan dari penelitian ini adalah untuk membandingkan kinerja kolektor surya glazed dan unglazed dalam kondisi cuaca yang samauntuk memanaskan air pada berbagai laju aliran air dan suhu inlet. Pendekatan penelitian yang digunakan dalam penelitian ini adalah pendekatan eksperimental, dimana data diperoleh dari proses pengukuran di lapangan. Parameter yang diukur meliputi suhu inlet, suhu outlet, suhu lingkungan, laju aliran, kecepatan angin dan iradiasi surya. Pengujian kolektor menggunakan empat buah kolektor (dua glazed dan dua unglazed). Hasil pengujian menunjukkan bahwa pada kolektor glazed, efisiensi tertingginya adalah 63%, sedangkan kolektor unglazed adalah 54%. Kedua efisiensi tersebut terjadi laju aliran 3 liter/menit dan suhuinlet 40°C dan waktu tengah hari. Biaya per watt (energi berguna) kolektor surya pelat datar glazed lebih rendah daripada kolektor surya pelat datar unglazed.
Proses Pembuatan Manisan Kering Ubi Jalar (Ipomoea Batatas L.) dengan Dehidrasi Osmotik dan Pengeringan Oven Winny Purnama Sari; Leopold Oscar Nelwan; Sutrisno .
Jurnal Keteknikan Pertanian Vol. 7 No. 1 (2019): JURNAL KETEKNIKAN PERTANIAN
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1168.64 KB) | DOI: 10.19028/jtep.07.1.33-40

Abstract

AbstractSweet potato (Ipomoea batatas L.) is a local food group that has the potential to be developed in order to support the program of diversification of non-rice food for food security, one of sweet potatoes product is sweet potatoes candied. The purpose of the study was to develop sweet potato manufacturing processfor osmotic dehydration and oven drying. Each sweet potato treatment is weighed 1000 grams, then immersed with citric acid (C6H8O7) 2% solution for 1 hour, the next step is sweet potatoes boiled 10 minutes at the concentration of sugar solution 32.8°Brix, 37.4°Brix, and 40.5°Brix, and then drying usingan oven at 50°C and 60°C for 5 hours. Parameters tested in this research were: Water content, total dissolved solid (TDS) Brix, water loss, solid gain. The water content of sweet potatoes as raw material from each treatment ranged from 70.03%-74.61%, the water content after boiling 10 minutes ranged from57.58%-72.64%, and the moisture content after drying for 5 hours ranged from 19.99%-20.58%. Total dissolved solids (TDS) after booiling for 10 minutes ranged from 24.8-26.0°Brix, and TDS after drying for 5 hours ranged from 67.2-74.0°Brix. Sweet potato water loss after boiling the osmotic solution for 10 minutes ranged from 1.21- 8.20%, sweet potato solid gain after boiling the osmotic solution for 10 minutes ranged from 2.25-17.06%.AbstrakUbi jalar (Ipomoea batatas L.) merupakan kelompok pangan lokal yang berpotensi untuk dikembangkan yang menunjang program diversifikasi pangan non beras menuju ketahanan pangan, salah satu produk olahan ubi jalar adalah manisan kering ubi jalar. Tujuan penelitian adalah untuk mengembangkan proses pembuatan manisan ubi jalar (Ipomoea batatas L.) terhadap dehidrasi osmotik dan pengeringan konvektif. Pada setiap perlakuan ubi jalar ditimbang beratnya yaitu 1000 gram, selanjutnya dilakukan perendaman dengan larutan asam sitrat (C6H8O7) 2% selama 1 jam, seterusnya ubi jalar direbus 10 menit pada konsentrasi larutan gula 32.8°Brix, 37.4°Brix, dan 40.5°Brix, selanjutnya dilakukan pengeringan menggunakan oven pada suhu 50°C dan 60°C selama 5 jam. Parameter yang dianalisis pada penelitian ini yaitu meliputi parameter proses kadar air, total padatan terlarut, water loss, solid gain. Kadar air ubi jalar sebagai bahan baku dari setiap perlakuannya berkisar antara 70.03%-74.61%, kadar air setelah perebusan 10 menit berkisar 57.58%-72.64%, kadar air setelah pengeringan selama 5 jam berkisar antara 19.99%-20.58%. Total padatan terlarut setelah peebusan dalam larutan osmotik selama 10 menit berkisar 24.8-26.0°Brix. Total padatan terlarut setelah pengeringan selama 5 jam berkisar 67.2-74.0Brix. Water loss ubi jalar setelah perebusan larutan osmotik selama 10 menit berkisar 1.21-8.20%, Solid gain ubi jalar setelah perebusan larutan osmotik selama 10 menit berkisar 2.25-17.06%.
Kajian Pengeringan Bak Gabah Secara Intermittent Terhadap Mutu Beras Achmad Fitrah Maulidin; Leopold Oscar Nelwan; Rokhani Hasbullah
Jurnal Keteknikan Pertanian Vol. 7 No. 3 (2019): JURNAL KETEKNIKAN PERTANIAN
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (984.448 KB) | DOI: 10.19028/jtep.07.3.171-178

Abstract

Grain drying with bed dryer is generally effective with high temperatures, but this can increase fissured rice percentage. This can be overcome by combining drying method with tempering. These study were aim to examine drying temperature and duration on bed dryer using intermittent high temperature dryer, and its effect on quality variety of Ciherang with 20-22% moisture content. These research method consists of drying treatment without tempering using 35°C, 60°C and 80°C temperatures to 14% moisture content. Drying treatment with tempering consists of initial drying process-initial tempering-second drying- second tempering or without tempering, where the first drying temperature were 80°C for 20 minutes, 60°C for 30 minutes and second drying temperature were 60 °C and 35°C to 14% moisture content. The tempering duration used was 90 minutes. Results showed the grain drying method without tempering 35°C gave the highest percentage of head rice. However, the use of tempering had significantly reduced cracking and increased head rice percentage compared without tempering at the same temperature. Initial drying of 60°C for 30 minutes-tempering for 90 minutes-drying both temperatures of 35°C to 14% moisture content had been able to produce high head rice and low fissured rice percentage respectively 81.41% and 10%.
Performance Analysis of Vapor Compression Heat Pump Dryer for Zedoary Drying (Curcuma zedoaria (Berg.) Roscoe) Hayatri Sali Setia; Leopold Oscar Nelwan; I Wayan Astika; Rokhani Hasbullah
Jurnal Keteknikan Pertanian Vol. 10 No. 2 (2022): Agustus 2022
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19028/jtep.010.2.123-132

Abstract

Zedoary (Curcuma zedoaria (Berg.) Roscoe) drying in simplicia form requires a proper treatment because the moisture content is high about 80–90 % that have perishable properties. Temperature, relative humidity and air flow rate are influential factors in drying medicinal plants then proper drying conditions need to be known. Dryer with vapor compression heat pump (VCHP) system is one of mechanical dryers as an alternative drying method to shorten drying time and maintain the quality. In this system, the environmental air flow is passed through the evaporator and condenser. The configuration of air flow passing through these two components is assessed in proportion to increase its effect on drying air conditions. The study aims to find the best configuration of air flow rate from VCHP which produces drying air conditions that are suitable for zedoary drying then analyze the performance of VCHP. The research was conducted by configuring the air flow and analyzing dryer performance of VCHP system. The results obtained the best configuration of air flow for zedoary drying are: (i) the air inlet before evaporator is given an inhibitor, (ii) the air inlet before condenser is closed. This configuration provides the highest sensible heating effect and the highest decrease in drying air humidity. VCHP performance test results for zedoary drying are: (i) COPhp is 3.11, (ii) STEC value is 4.066 MJ/kg, (iii) SMERT value is 0.870 kg/kWh, and (iv) SMERTot value is 0.449 kg/kWh. The STEC, SMERT and SMERTot values obtained are affected by drying time.
The Study of Paddy Dryer Using Basalt Stone As Heat Storage Media From Biomass Combustion M Ridwan Dwi Astanto; Leopold Oscar Nelwan; Edy Hartulistiyoso
Jurnal Keteknikan Pertanian Vol. 10 No. 3 (2022): Desember 2022
Publisher : PERTETA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19028/jtep.010.3.305-318

Abstract

The objectives of this research were to study the characteristics of thermal storage basalt rock by using biomass combustion with respect to manual adjusted airflow, combustion rate and the gap distance between the storage base and the furnace base as well as to evaluate the performance of the heat storage system for paddy drying. The heat storage characteristics experiment was carried out in two stages, namely heat charging and discharging. The tests were carried out with two gap distances, namely 23 cm and 30 cm. In general, the closer distance (23 cm) gives better performance, where at the targeted outlet temperature of 40˚C, an average discharging time of 664 minutes and a discharging efficiency of 73.5% were obtained. At the targeted outlet temperature of 45˚C, an average discharging time of 452 minutes with an average discharging efficiency of 65.75% were obtained. Furthermore, the heat storage system was applied for paddy drying. The drying experiment was carried out twice, each using an average outlet air temperature of 45.5˚C and 41.4oC with an initial grain moisture content of 22.82 and 13.88 %w.b., respectively. Drying time of 360 minutes for the first experiment and 420 minutes for the second experiment with specific energy consumption of 5.45 MJ/kg evaporated water and 5.31 MJ/kg evaporated water, respectively were obtained. Even though it uses direct heating by using coconut shell combustion, this drying method did not affect the aroma of the rice produced.
Thermal Characteristics of Coconut Shells as Boiler Fuel Muhamad Yulianto; Edy Hartulistiyoso; Leopold Oscar Nelwan; Sri Endah Agustina; Chandra Gupta
International Journal of Renewable Energy Development Vol 12, No 2 (2023): March 2023
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2023.48349

Abstract

Agricultural waste products, such as wood, rice husk, corn waste, and coconut shells, are abundantly available  and can potentially be used as an energy source, particularly  for direct combustion in boilers. Because coconut production increases every year, it would be useful to find an alternative use for coconut shells, which are a type of coconut waste. As coconut shells can be used as fuel in boilers, the aim of this study was to evaluate the thermal characteristics of coconut shells in this regard. This study used experimental results to evaluate the performance of a boiler when coconut shells were used as solid fuel. The variations in feed rate were 5, 7.5, and 10 kg/h, and the water flow rates varied between 1 litre per minute (lpm), 2 lpm, and  3 lpm. Temperature data were collected every second via data acquisition , and the mass flow rate of the flue gas was collected every 5 min using a pitot tube equation. One of the parameters evaluated in determining the success of coconut shells as boiler fuel is the thermal efficiency of the boiler. The results showed that the maximum thermal efficiency reached approximately 62.04%, and the maximum flue gas temperature was approximately 500 ℃ for a biomass mass flow rate of 7.5 kg/h. The maximum water temperature of the boiler was 99 ℃, which was reached at a minimum water flow rate of 1 lpm. The results showed that coconut shells are suitable for use as boiler fuel. 
Pengaruh Tinggi Tumpukan dan Proses Tempering Terhadap Mutu Gabah yang Dikeringkan dengan Fluidized Bed Dryer Devi Tanggasari; Leopold Oscar Nelwan; Muhamad Yulianto; I Wayan Astika
Warta Industri Hasil Pertanian Vol 39, No 2 (2022)
Publisher : Balai Besar Standardisasi dan Pelayanan Jasa Industri Agro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32765/wartaihp.v39i2.5434

Abstract

Salah satu pengeringan mekanis yang dapat diterapkan untuk mengeringkan gabah yaitu fluidized bed dryer (FBD), namun penggunaan suhu tinggi yang terlalu lama dapat mempengaruhi kualitas gabah yang dihasilkan sehingga diperlukan proses tempering. Tempering dilakukan diantara pengeringan pertama dan pengeringan selanjutnya untuk mencegah terjadinya keretakan. Tujuan penelitian ini adalah menguji kinerja pengeringan FBD dua tahap dengan dan tanpa tempering, serta menguji mutu beras berdasarkan persentase beras kepala dan beras patah hasil pengeringan menggunakan FBD dengan dan tanpa tempering yang dilanjutkan dengan pengeringan pada suhu udara lingkungan. Secara garis besar gabah dikeringkan menggunakan alat pengering FBD hingga kadar air ±20% basis basah dengan tinggi tumpukan 10 dan 15 cm, kemudian dilanjutkan dengan proses tempering dan dikeringkan menggunakan udara lingkungan. Fluidisasi dapat berlangsung dengan baik pada kisaran kecepatan superfisial 3,963-3,946 m/s di tinggi tumpukan 10 cm dan 3,640-3,623 m/s pada tinggi tumpukan 15 cm. Persentase beras kepala yang paling tinggi terdapat pada perlakuan yang menggunakan tempering selama 2 jam dan dilanjutkan dengan kering angin lingkungan sebesar 96,38+0,180% pada tinggi tumpukan 10 cm dan 92,38+0,333% pada tinggi tumpukan 15 cm, sedangkan perlakuan tempering yang dikeringkan kembali menggunakan FBD menghasilkan persentase beras kepala yang lebih tinggi dibandingkan dengan perlakuan tanpa tempering yaitu sebesar 86,23+0,201% pada tinggi tumpukan 10 cm dan 84,41+0,279% pada tinggi tumpukan 15 cm.
Pengaruh Laju Umpan Bahan Bakar dan Laju Aliran Udara terhadap Kinerja Pembakaran Tungku Fixed Bed Tamaria Panggabean; Tineke Mandang; Leopold Oscar Nelwan; Wawan Hermawan
agriTECH Vol 43, No 1 (2023)
Publisher : Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/agritech.70508

Abstract

Penelitian ini dilatarbelakangi kelemahan pembakaran tungku yang menghasilkan pembakaran yang tidak sempurna dikarenakan kurang optimalnya rasio bahan bakar dan udara serta waktu tinggal pembakaran yang singkat. Penelitian ini bertujuan untuk memperoleh laju umpan bahan bakar dan laju aliran udara yang menghasilkan pembakaran sempurna. Makalah ini menjelaskan pengaruh laju umpan bahan bakar dan laju aliran udara terhadap kinerja pembakaran tungku fixed bed sebagai sumber energi panas pengering. Pengukuran efisiensi tungku dilakukan pada berbagai laju umpan sekam dan laju aliran udara. Penelitian ini dilakukan pada 3 laju umpan sekam yaitu 12, 15, dan 18 kg/jam, dan pada 5 laju aliran udara yaitu 86,4; 120,96; 114,84; 108 dan 154,8 kg/jam. Perlakuan optimum diperoleh pada laju umpan sekam 15 kg/jam dan laju aliran udara 114,84 kg/jam dengan efisiensi tungku sebesar 73,99%, panas yang dihasilkan 41,55 kW dan dan % abu/arang yang diproduksi 17,89%. Suhu gas buang bervariasi dari 99,78-474,23°C pada berbagai laju umpan sekam dan laju aliran udara. Analisis gas buang menunjukkan pelepasan panas maksimum terjadi ketika tungku diberi kelebihan udara berlebih 100% yang dibutuhkan untuk pembakaran sempurna.
Co-Authors Achmad Fitrah Maulidin Ali Usman, Ali Bandul Suratmo Budi Rahardjo Chandra Gupta Damawidjaya Biksono Devi Tanggasari Dwi Setyaningsih Dyah Wulandani Dziyad Dzulfansyah Edy Hartulistiyoso Eko Heri Purwanto Emmy Darmawati Erlanda Augupta Pane Hayatri Sali Setia Herry Suhardiyanto I Nengah Suastawa I Wayan Astika I Wayan Budiastra Irwansyah Irwansyah Kudang Boro Seminar M Ridwan Dwi Astanto Mila Siti Amalia Mohamad Solahudin Mohammad Aftaf Muhajir Muhamad Yulianto Muhamad Yulianto Nurul Choerunnisa Omil Charmyn Chatib Putri Ayu Ira Distriani Ranti - Ranti Rokhani Hasbullah Rustam Efendi Samsudin Samsudin Sigit Triwahyudi Siregar, Gokma Ampetua Sofyan Sjaf Sri Endah Agustina Sulikah . Sutrisno . Syahputra, Sufri Yanto Tamaria Panggabean Tineke Mandang Tri Yulni Tya Lestari Usman Ahmad Wawan Hermawan Winny Purnama Sari Y. Aris Purwanto Yogi Sirodz Gaos Yusnita Oni Napitu