Time Estimation of Onion Leaf Drying

The main process of the onion post harvest treatment is drying proces. High moisture content of onion leaf and outer layer of onion must be reduced up to moisture content 12% or below (wet basis). This level keeps onion being still fresh. The conventional drying with direct sunlight still has been widely used because of the cheap process. However, this technique needs too long drying time as well as climate dependency. This research evaluated convective dryer for onion leaf drying. The mass transfer coefficient, and moisture diffusivity was estimated to predict effective drying time. Results show that the drying time was shorter as the temperature and air velocity increased. For example, at 60oC and air velocity 0.5 m.s-1, the drying time was about 19 hours. The drying time can be can be 5hours shorter at higher air velocity. In addition,with increase of air velocity, the drying time can be also speeded up, significantly. Here, the air temperature must be kept at maximally 60oC in order to avoid onion degradation. Therefore, the increase of air velocity is a good option to shorten drying time and retain the quality

Time Estimation of Onion Leaf Drying

The main process of the onion post harvest treatment is drying proces. High moisture content of onion leaf and outer layer of onion must be reduced up to moisture content 12% or below (wet basis). This level keeps onion being still fresh. The conventional drying with direct sunlight still has been widely used because of the cheap process. However, this technique needs too long drying time as well as climate dependency. This research evaluated convective dryer for onion leaf drying. The mass transfer coefficient, and moisture diffusivity was estimated to predict effective drying time. Results show that the drying time was shorter as the temperature and air velocity increased. For example, at 60oC and air velocity 0.5 m.s-1, the drying time was about 19 hours. The drying time can be can be 5hours shorter at higher air velocity. In addition,with increase of air velocity, the drying time can be also speeded up, significantly. Here, the air temperature must be kept at maximally 60oC in order to avoid onion degradation. Therefore, the increase of air velocity is a good option to shorten drying time and retain the quality

Paddy Drying in Batch Fluidized Bed and Scale-up Simulation in Continuous Operation Mode

The objective of this research is to develop the industrial-scale fluid bed dryer for paddy by scale-up of lab-scale experimental data. The developed dryer was conducted by simulation using a two phase model. Firstly, the experimental works by using lab-scale batch fluid bed dryer, was conducted to determine the drying curve of paddy (Xin 0.32 kg/kg dry base). In the experimental works,the inlet air temperature was varied (°C): 40; 50; 60. The drying rate curves as a function of moisture content showed only decreasing drying rate period. Then, a very good agreement between the measured and simualtion results of the profile of moisture content in solids was produced by simulator. Finally, asimulated continuous fluidized bed dryer for paddy with dimension 5 m of length and 1.5 of width was succesfully performed, in which the influence of mass solid flow rate 0.1; 0.2; 0.4 tons/h, height of bed 0.25; 0.50; 0.75 m, and air temperature 50; 70; 100 °C on drying process were studied. Keywords: Paddy; fluid bed dryer; batch, contonious;  modelling; simulatio

Shell and Tube Heat Exchanger Fouling Factor via Heat Transfer Research Inc (HTRI) Software

One of the factories for manufacturing Carboxymethyl Cellulose (CMC) uses a shell and tube-type heat exchanger as a condenser. The shell and tube (HE) heat exchanger consists of small diameter tubes arranged in a cylindrical shell. In the tube and shell sections, hot (ethanol) and cold (water) fluids will flow so that heat transfer occurs directly. The use of heat exchangers regularly will reduce the performance of the tool. Due to the increasing fouling layer inside the HE, the device will work harder, and the heat process could be more optimal. It is necessary to analyze the performance of the heat exchanger using the parameter value of the fouling factor (Rd). The fouling factor can be calculated using the manual calculation method (via the Kern method) and the HTRI program. The involvement of the mathematical equation in the first method will be configured for the calculation results through process simulation in the HTRI software. Both ways are used for calibration between manual calculations and the HTRI software for the Rd values obtained. The fouling factor can be calculated using the manual method and HTRI software. The two methods used for calibration are manual calculations with HTRI software. The results from this analysis give a decrease in tool performance with a fouling factor of 0,01 Btu/(h.ft2.℉). ABSTRAKSalah satu pabrik pembuatan Carboxymethyl Cellulose (CMC) menggunakan heat exchanger tipe shell and tube sebagai kondensor. Heat exchanger (HE) shell and tube terdiri dari sekumpulan tube berdiameter kecil yang disusun di dalam shell berbentuk silindris. Pada bagian tube dan shell akan dialirkan fluida panas (etanol) dan dingin (air) agar terjadi proses perpindahan panas secara tidak langsung. Penggunaan heat exchanger secara berkala akan mengurangi kinerja alat. Hal tersebut disebabkan oleh adanya lapisan fouling yang terus meningkat di bagian dalam HE sehingga alat akan bekerja lebih berat dan proses perpindahan panas tidak maksimal. Untuk mengatasi fenomena tersebut maka perlu dilakukan analisis kinerja heat exchanger menggunakan parameter nilai fouling factor (Rd). Fouling factor dapat dihitung menggunakan metode perhitungan manual (melalui metode Kern) dan penggunaan program HTRI. Keterlibatan persamaan matematis pada metode pertama akan dikonfigurasi hasil perhitungannya melalui simulasi proses pada software HTRI Kedua metode digunakan untuk kalibrasi antara perhitungan manual dengan software HTRI atas nilai Rd yang didapatkan. Hasil analisis perhitungan dengan kedua metode tersebut menghasilkan penurunan kinerja alat dengan nilai fouling factor sebesar 0,011 Btu/(jam.ft2.℉).

Development of A Novel Energy-Efficient Adsorption Dryer Using Activated Natural Zeolite for Carrageenan Production

Drying is a significant step in the production of carrageenan. However, current drying process still deals with low energy efficiency (40-45%), high operational cost, and low product quality. The drying with air dehumidified by activated natural zeolite has a potential for drying carrageenan. In this concept, air as drying medium will be contacted with zeolite to reduce its relative humidity. Hence, the driving force of drying increases and the process can be conducted at moderate temperature (30-50oC) to retain carrageenan quality. This research looks into the effectiveness of adsorption dryer with zeolite for drying carrageenan. The natural zeolite is activated by heating 300-400oC for 2-3 hours. The zeolite is then used to dehumidify the ambient air as drying medium. In this work, the effect of air flow, and drying temperature, on energy efficiency, as well as drying time, is observed. Results showed with air velocity 1.0-1.5 m/sec, weight of wet carrageenan in dryer 1.0 kg, and temperature 40oC, the drying time can be 1.5 hours (0.5-1 shorter than that of conventional dryer), and improvement of energy efficiency can be 5-10% higher than the conventional dryer. This result is very promising to develop the dryer for industrial application

APLIKASI SPRAY DRYER UNTUK PENGERINGAN LARUTAN GARAM AMONIUM PERKLORAT SEBAGAI BAHAN PROPELAN

Ammonium perchlorate ( AP ) is an inorganic oxidizer that is widely used as a component of rocket propellants. In this research, spray drying was used to produce crystalline AP from its saturated solution. A method of spray dryer is viscous liquid or paste contacted with thot air co-currently. Fluid is passed at a nozzle and came out into the form of fine granules ( droplet . Drying method was conducted to run4 variables change, such as the inlet temperature (80, 90, 100, 110, 120oC), flow rate air dryer (9,1 and 16.3 m/s), the material flow rate (5.5 and 5.8 ml/s) and material concentration (5, 10, 15, 20, 25% salt). The drying process lasts for 13 minutes and divided into 3 minutes of time spraying and 10 minutes for residence time in a spray dryer column.At a temperature of80° C, the concentration of20%, materialflow rateof 5.5ml/sand aair flow rate of9.1m /sobtainedsaltparticlediameterof67.144µmthen calculatesimilarityusingWebernumber, obtainedAPdiameter of42.79µm.While ata temperature of 100° C, the concentration of20%, with asame material and air flow rate,obtaineddriedsaltparticle diameterof23.433µm.Afterwards,similaritycalculationusing theWebernumberobtainedAPdiameter13.877µm. It can be seenthatthe result ofAPdiametersmaller than thediameter of theparticlesinLAPAN (National Aeronautics and Space Institute), rangedbetween100-170µm. We can conclude that the higher concentration of salt solution, then the diameter of products are also getting bigger. The higher temperature then the diameter of products are getting smaller. Calculation of similarity both ammonium perchlorate and salt with the weber number has the same graph trends

Optimization foam mat drying of roselle (

In this study, foaming condition of roselle was optimized using response surface methodology (RSM) and the effect of drying characteristic was investigated. Roselle extract was foamed by addition of 1-5% w/w foaming agents (ovalbumin). The foaming stabilizer, glycerol mono stearate (0-1% w/w) was used to remain mechanic and thermodynamic stability of foam. As the response foam density and drainage volume was determined. The optimum foam variable was then dried at various drying temperatures (50-70°C). The moisture content was observed by gravimetry every 10 minutes for 90 minutes. Result showed that optimum formulation was 3.31% egg albumin and 1% GMS. The constant rate of the foam mat drying (temperature 50°C) was 3 times higher than non foam mat drying. Higher drying temperature can speed up the driving force but lead to color degradation

RANCANG BANGUN PENGERING SEBAGAI UPAYA MEMPERBAIKI KUALITAS TEH BUNGA ROSELA PADA ASPETRI (Asosiasi Pengobat Tradisional Ramuan Indonesia) CABANG SEMARANG

Khalayak sasaran kegiatan pengabdian program Vucer berlokasi di Kota Semarang, Kecamatan Pedurungan yang berjarak sekitar 15 km dari Universitas Diponegoro Tembalang yang merupakan kelompok usaha tanaman obat dan khususnya teh bunga rosela yang tergabung dalam ASPETRI (Assosiasi Pengobat Ramuan Indonesia) Cabang Semarang. Metode pendekatan yang digunakan adalah didasarkan pada analisis situasi kelompok sasaran (masalah, potensi dan peluang), model sistem pengeringan yang ada pada literatur, dan karakteristik bahan yang akan dikeringkan. Kegiatan program vucer Mi bertujuan merancang dan membuat alat pengering bunga rosela yang digunakan sebagal teh kesehatan. Peralatan ini dirancang secara mekanis yang digunakan untuk menggantikan teknik pengeringan secara Marra yang dilakukan dengan pemanasan langsung dari sinar matahari di tempat terbuka. Peralatan ini selain dapat menjaga keberlangsungan proses produksi teh bunga rosela terutama pada waktu musim hujan juga menjaga higienitas produk teh bunga rosela karena dilakukan pada tempat tertutup (ruang pengering) dan mempercepat proses pengeringan menjadi 0,5 jam. Alat tersebut dapat meningkatkan kapasitas produksi pengeringan dari 3 kg/hari menjadi 5 kg/hari yang dikerjakan oleh 1 prang. Nat pengering menggunakan teknik pengeringan tidak langsung dengan menggunakan udara panas yang dihasilkan dari generator panas dengan sumber dari kompor gas. Bagian utama alat pengering terdiri dari tiga unit, yaitu unit transport udara, unit pemanas udara dan ruang pengering. Udara panas dengan suhu 600 C masuk almari pengering dengan bantuan blower. Udara mengalir melalui pipa besi yang kemudian disalurkan masuk almad pengering menggunakan pipa karat yang ileksibel. Temperatur dijaga stabilitetap pada suhu 60°C yang dapat dilihat dad termometer yang terpasang yang dikontrol dengan pengaturan kontrol kompor gas dan pompa vakum. Komponen utama alat pengering dirancang secara terpisah sehingga dapat dibongkar pasang dengan mudah. Perawatan, pengawasan dan perbaikan komponen apabila mengalami gangguan dapat dilakukan secara sederhana dan mudah

Aplikasi Spray Dryer Untuk Pengeringan Larutan Garam Amonium Perklorat Sebagai Bahan Propelan

Ammonium perchlorate ( AP ) is an inorganic oxidizer that is widely used as a component of rocket propellants. In this research, spray drying was used to produce crystalline AP from its saturated solution. A method of spray dryer is viscous liquid or paste contacted with thot air co-currently. Fluid is passed at a nozzle and came out into the form of fine granules ( droplet . Drying method was conducted to run4 variables change, such as the inlet temperature (80, 90, 100, 110, 120oC), flow rate air dryer (9,1 and 16.3 m/s), the material flow rate (5.5 and 5.8 ml/s) and material concentration (5, 10, 15, 20, 25% salt). The drying process lasts for 13 minutes and divided into 3 minutes of time spraying and 10 minutes for residence time in a spray dryer column.At a temperature of80° C, the concentration of20%, materialflow rateof 5.5ml/sand aair flow rate of9.1m /sobtainedsaltparticlediameterof67.144µmthen calculatesimilarityusingWebernumber, obtainedAPdiameter of42.79µm.While ata temperature of 100° C, the concentration of20%, with asame material and air flow rate,obtaineddriedsaltparticle diameterof23.433µm.Afterwards,similaritycalculationusing theWebernumberobtainedAPdiameter13.877µm. It can be seenthatthe result ofAPdiametersmaller than thediameter of theparticlesinLAPAN (National Aeronautics and Space Institute), rangedbetween100-170µm. We can conclude that the higher concentration of salt solution, then the diameter of products are also getting bigger. The higher temperature then the diameter of products are getting smaller. Calculation of similarity both ammonium perchlorate and salt with the weber number has the same graph trends