POROS

HUBUNGAN NILAI CE DENGAN LAPISAN KULIT THIN WALL DUCTILE IRON

2023-12-11T02:16:55+00:00

The formation of skin effects in nodular cast iron produced using sand molds is a general problem. Since it can be cleaned during the machining process along with gating system removal. Skin effects become a problem when they form in nodular cast iron thin wall castings. In thin-wall castings, the skin effect becomes a problem because the cleaning process is difficult to perform. Therefore, a mechanism is needed to avoid the formation of skin effects in nodular cast iron thin wall castings. This work is carried out to see the effects of carbon equivalent (CE) as one of the important parameters during the casting process to the formation of skin effects, especially when the cast object produced is a component. Molten metals with different CE values are used to make thin wall ductile iron connecting rod components. Microstructure observations were carried out both in the I-beam and end-rod areas. Then the results obtained are compared with the previous research regarding the skin effects formed in thin-wall ductile iron plates. The result obtained is that the skin effects detected in thin-wall ductile iron connecting rods with different types of patterns and thicknesses from that formed on the plate.

SIMULASI STRESS PADA MESIN PENIRIS MINYAK BAWANG GORENG DENGAN KAPASITAS TIGA KILOGRAM

2023-10-26T06:33:31+00:00

Every food that is frequently consumed nowadays usually uses cooking oil as a frying tool. Indonesian people, both in urban and rural areas, consume fried foods in their daily lives. Therefore, by designing an oil drainer, we can overcome the problem in terms of time in draining oil from fried onions. In this oil dryer there are main components to drive the oil dryer system in the form of perforated baskets, shafts, AC electric motors, v-belts, pulleys, bearings, and table. The material used in this oil dryer uses food grade materials, for the safety and health of users of this oil dryer. The oil dryer has a capacity of 3 kg at one time the frying of fried onions is then calculated to find out which material is suitable for use in the oil slicer, then performs a simulation to determine the strength of the material selection used.

ANALISIS KINERJA HEAT EXCHANGER TIPE SHELL AND TUBE DENGAN MODIFIKASI BAFFLE

2022-08-25T05:37:11+00:00

Heat exchanger tipe shell and tube mempunyai komponen-komponen utama dalam sususannya seperti, pipa, shell, front-end head, rear-end head, sekat (baffles), dan tube sheets. Pemasangan sekat pada heat exchanger shell and tube berfungsi sebagai penyangga pipa dan mengalirkan aliran fluida melintasi antar pipa-pipa untuk mendapatkan nilai koefisien perpindahan panas yang baik. Tetapi, pemasangan sekat dapat membuat fluida tidak terdistribusi di zona atau titik sisi belakang sekat yang tidak terhantam aliran fluida secara langsung dari inlet shell sehingga tidak terjadi pertukaran panas antara fluida yang mengalir di pipa dengan shell. Oleh karena itu, dilakukan penelitian eksperimental heat exchanger shell and tube - tipe laboratorium dengan memodifikasi bagian sekat yaitu menambahkan sebuah plat atau sirip di sisi sekat yang bertujuan mengubah pola aliran fluida dalam shell dan diharapkan fluida dapat mengalir ke bagian spot atau zona yang sebelumnya tidak terjadi pertukaran panas antara kedua fluida. Dalam penelitian ini digunakan heat exchanger shell and tube tipe one pass shell, aliran counterflow, dan sekat yang digunakan tipe single segmental cut 20%. Eksperimen dilakukan dengan memvariasikan laju aliran. Hasil data eksperimen berupa temperatur, variasi massa laju alir, dan dimensi dari peralatan dikumpulkan dan digunakan untuk menghitung overall heat transfer coefficient, bilangan Reynolds, bilangan Nusselt, pressure drop dan efektivitas heat exchanger menggunakan metode ε-NTU. Hasil menunjukkan bahwa pada variasi laju alir dengan 1.8 l/min pada sisi pipa dan 7 l/min pada sisi shell mendapatkan nilai efektivitas tertinggi sebesar 87.28%.

PENGARUH PEMBESARAN DIAMETER DAN PEMOLESAN INLET PORT PADA MESIN 4 TAK 150CC SOHC TERHADAP UNJUK KERJANYA

2023-10-30T03:02:38+00:00

Porting & polishing is the process of enlarging the diameter of the cylinder head intake and exhaust duct holes, as well as smoothing the surface. This modification is carried out manually by a mechanic who has experience. This research examines changes in diameter and surface roughness on machine performance, namely power and torque. A number of samples with volume of cylinder 148,7 cc motorbikes were ported & polished manually for 1, 2 and 3 hours. Changes in diameter and surface roughness were recorded both before and after processing. Next, using a Dynoyet 250i dynamometer, power and torque measurements were carried out. A smooth surface will cause the fuel to touch the surface and evaporate, thus increasing the mixture of air and fuel because both are in the same phase and condition. Furthermore, in the diameter change range of up to 10.36% from the initial diameter, it was recorded that the increase in power and torque could reach 8.94%. In this way, porting & polishing is able to fulfill the racers' desires for competition activities

PEMBANGKITAN TEGANGAN MENGGUNAKAN KARBON AKTIF TEMPURUNG KELAPA DENGAN VARIASI PROSENTASE NACL

2024-03-15T03:09:24+00:00

Fossil fuels as energy generators have been identified as the main cause of environmental pollution, besides that their supplies are running low. Energy from fossil fuels can cause global warming and climate change due to the carbon dioxide gas emissions produced, causing a greenhouse effect. Therefore, to generate electrical energy, environmentally friendly materials are needed, one of which is coconut shell-activated carbon. This research aims to generate voltage using coconut shell-activated carbon with varying percentages of NaCl. The voltage generation model is composed of counter electrodes – electrodes – counter electrodes. The electrode used is coconut shell-activated carbon, while the counter electrode is copper. The electrolyte used was a NaCl solution with NaCl percentages of 5%, 10% and 15% respectively. The NaCl electrolyte is injected into the model between the electrode and the counter electrode, then heat is applied. An electrostatic force occurs between the ions from the NaCl electrolyte and the surface of the coconut shell-activated carbon, namely the functional groups, pores, and copper counter electrode. The results show that the higher the percentage of NaCl electrolyte, the higher the voltage produced. The resulting voltage is 0.091 volts at a NaCl percentage of 5%, 0.181 volts at a NaCl percentage of 10%, and 0.212 volts at a NaCl percentage of 15%.

PENGARUH VARIASI FLUKS TERHADAP SIFAT FISIK DAN MEKANIK HASIL SAMBUNGAN LAS GMAW (GAS METAL ARC WELDING) BAJA AISI 1018

2024-03-26T07:31:14+00:00

The aimed of this study was to determine the effect of flux variations on physical and mechanical properties of GMAW welded joints. This research uses AISI 1018 steel with a size of 300 mm x 100 mm and a thickness of 5 mm. The welding process is carried out using the Gas Metal Arc Welding (GMAW) method, ER70S-6 filler and shielding gas mixture of Argon and CO2 (50% and 50%). The flux variations used are ZnO, Al₂O₃, dan SiO₂.. The tests carried out are dye penetrant testing, chemical composition testing, microstructure observation, tensile testing, bending testing and hardness testing. The results of dye penetrant testing show that welding results with all flux variations can be well jointed. Testing the chemical composition of the welding results shows that the chemical elements of the welding results will rise according to the main chemical elements of the flux. . The highest value of tensile strength and bending strength of welds is found in welds with the addition of ZnO flux. . This is in accordance with the results of microstructure observations that show welds with ZnO flux have the most microstructures in the form of accicular ferrite compared to grain boundary ferrite and widmanstatten ferrite. Accicular microstructure will increase the strength and toughness of the material due to its small shape and random directional orientation. The hardness number of welding results for all welding variations has almost the same value, which is approximately 190 VHN.