Claim Missing Document
Check
Articles

Found 3 Documents
Search
Journal : Jurnal technoscientia

UNJUK KERJA ALAT PENGERING GULA SEMUT DUA BELAS SUSUN MENGGUNAKAN BAHAN BAKAR LPG Johanes, Susanto; G., Sukartono,; S., Soeadgihardo
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 7 No 2 Februari 2015
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (215.788 KB) | DOI: 10.34151/technoscientia.v7i2.205

Abstract

Modified dryer is used as an alternative methodfor drying the production of coconut sugars (gula semut / gula merah) or coconutcrystal sugars for farmers or micro entrepreneurs, especially when production is increased or in the rainyseason. This study aims to determine the performance of drier gula semut own design, with LPG fuel. Construction drier consists of a framework to support stainless steel pans as the container of sugars, measuring 78 cm x 74 cm x 4 cm, which is composed of twelve level, with a gap distance of 5 cm. The pans arranged vertically, so that the bottom of the pan gets hot either by radiation, conduction, and convection by the flow of hot air that is exhaled by the blower, while the pans that is above it also will get heat by conduction and convection by hot air which flows through it. The tests of dryers are conducted in two methods: with load and without load. The weather conditions are dry bulb temperature of 30°C and 27°C wet bulb. In the no-loaded testing, to achieve a working temperature of the drying chamber at 60 °C, it takes approximately 40 minutes. While testing with load is drying 8 kg / pan and 10 kg / pan sugars. On this burden, to reduce the water content of about 6% to between 2-3%, required 5.5-7 hoursdrying time, and required the consumption of fuel (LPG) between 1.15 to 1.35 kg. The rate of the average water content decreasedis 0.66% per hour, and the total efficiency of the dryer (ηT) is 23%.
KARAKTERISTIK MENARA PENDINGIN DENGAN BAHAN ISIAN TALI IJUK Johanes, Susanto
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 4 No 1 Agustus 2011
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (921.464 KB) | DOI: 10.34151/technoscientia.v4i1.494

Abstract

In this study the characteristics of a water cooling tower with palm fibre as the packing material have been investigated experimentally. The experiments were carried out in a rectangle glass tower of 81 cm2 cross sectional area and 100 cm height. The packing used was constructed of 8 palm-fibre ropes (of about 0,6 cm diameter), zigzag and cross of water flow, and then it placed above the stainless steel support on the tower bottom. There were two type of packing i.e. 21,7.10-4 and 28,3.10-4 kg weigh of rope every m3 volume of the packing. The experimental results show that the increasing of the water inlet temperature and packing height causes the increasing of the tower characteristic . Mean while the increasing of the water/air mass flow rate ratio causes the decreasing of the tower characteristic.The tower characteristics is as a function of the investigated variables which expressed as: NTU = 165,24.10-3 (mw/ma)-0,999 (Z)0,5343 (Twi)0,1429 . It is for 21,7.10-4 kg/m3 of the specification of the packing material, with the relative error of 6,1 %, and NTU = 3,35.10-3 (mw/ma)-0,995 (Z)0,5050 (Twi)1,1643. It is for 28,3.10-4 kg/m3 of the specification of the packing material, with the relative error of 5,5 %.These equations are valid for the range variables, they are mw/ma of 4,46 – 9,48, Z of 30 – 90 cm, Twi of 50 – 60 oC. The mean effectiveness of the heat transfer were calculated to be 24,8 % and 25,9 %, respectivally for 21,7.10-4 and 28,3.10-4 kg/m3 of the specifications of the packing material.
KAJIAN EKSPERIMENTAL TERHADAP KONDUKTIVITAS DAN DIFUSIVITAS TERMAL BUAH SEMANGKA Johanes, Susanto
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 5 No 1 Agustus 2012
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1594.91 KB) | DOI: 10.34151/technoscientia.v5i1.525

Abstract

In the tropics, when the fruit is going to be cropped, the fruit temperature is same as the ambient temperature. It could reach more than 40 degree Celcius. One of the methods to make the fruit not easily damaged at the post-harvest is by applying the pre-cooling method. It aims to retard the respiration, minimize the vulnerability from the attack of micro-organisms, reduce the loss of water, and reduce the cooling load on the carrier and also the storage system. The fruit thermal conductivity and diffusivity values become the first important data to be recognized in order to determine the precooling time pro-cess to the desired temperature.The research is aimed to recognize the watermelon thermal conductivity and diffusivity values. Modeled as a ball shaped object, the water-melon is chilled in the cooler by natural convection. In the cooling process, the changing temperature in its fruit was recorded in the computer by using IC LM 35 sensors, every 5 minutes. The sensor was set in the ambient, on the fruit surface and in it’s inside with five different radius. There were three of watermelon by weight as 2,590 kg, 3,925 kg and 5,195 kg had been observed.In this research, the calculation of the watermelon thermal conductivity and diffusivity was based on the thermal resistance and capacity formulation. By numerical method, the average value of watermelon thermal conductivity was calcu-lated as 0,438 W/moC. Meanwhile the average value of thermal diffusivity was calculated as 1,137x10-7 m2/s.