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Perilaku Antarmuka Berdasarkan Data Beda Tekanan pada Peristiwa Kondensasi Aliran Uap Dengan Pendinginan dari Luar Searah pada Pipa Horisontal Berbasis Domain Waktu Sukamta Sukamta; Hasan Asy Ari Dwiearto; Sudarja Sudarja
Semesta Teknika Vol 21, No 1 (2018): MEI 2018
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.211214

Abstract

A two-phase flow pattern experiment on the condensation event of steam flow with external cooling based on the measurement of pressure difference within a horizontal pipe is carried out by varying the superficial velocity. Annulus pipes with inner pipe material made of copper and outer pipe made of galvanized iron (GIP) within an insulation of 10 mm thick were used in this experiment. The length of the pipe is 1.6 meters, outer diameter of 4 inch and inner diameter of 17 mm. The two-phase flow pattern was investigated based on differential pressure fluctuations between the inlet and outlet. To support the observation, flow pattern visualization was performed using a transparent pipe with a diameter of ¾ inch and a length of 1.3 meters connected to the test pipe section. The superficial vapor velocity was carried out from JG = 0.0689 m/s to JG = 1,9117 m/s. The results showed stratified flow patterns for the lowest superficial velocity and also obtained wavy, wavy-slug, and slug. Annular flow patterns can not be observed in this experiment. In general, increasing superficial velocity of steam will cause a significant increase in pressure fluctuations.
Identifikasi Pola Aliran Dua Fasa Uap-Kondensat Berdasarkan Pengukuran Beda Tekanan pada Pipa Horisontal Sukamta Sukamta; Indarto Indarto; Purnomo Purnomo; Tri Agung Rohmat
Semesta Teknika Vol 13, No 1 (2010): MEI 2010
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v13i1.728

Abstract

An experiment of two-phase flow patterns of steam-condensate based on differential pressure measurement in horizontal tube was conducted by varying the flow rate of the steam. The experiment utilised annulus pipe with inner section test pipe was made from copper and outer section was made from Galvanized Iron Pipe (GIP) wrapped with a 10-mm-thick insulation. The pipe was 1.6 meter length, and 4 inch outer diameter and 17 mm inner diameter. The two-phase flow regime was investigated based on pressure gradien between its inlet and outlet. In order to support the result, visualition was conducted using a ¾ inch diameter and 1.3 m length of transparent pipe connected with the test pipe section. Five variations of steam flow rate ranging from 0.00211361 m3/s to 0.007078511 m3/s were selected. The results show that for lowest steam flow rate, stratified flow pattern was identified while for the ot her variations, stratified, wavy, plug and slug flow pattern were observed. Wavy flow pattern occured on transition of stratified to slug or plug. Annular flow pattern was not observed in this experiment. Generally speaking, an increase in steam flow rate resulted in a more significant pressure gradient signals.
Pembuatan Alat Incinerator Limbah Padat Medis Skala Kecil Sukamta Sukamta; Andri Winata; Thoharuddin Thoharuddin
Semesta Teknika Vol 20, No 2 (2017): NOVEMBER 2017
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v20i2.3558

Abstract

Trash is one of the major problems in big cities. Trash has negative impact on the environment, because waste can cause environmental pollution, as well as hygiene and health problems. For processing the solid medical waste, it must be combusted at temperatures higher than 800 °C to reduce combustible garbage that can no longer be recycled, and toxic chemicals, to kill bacteria and virus. In energy efficient perspective, to overcome this, an incinerator has been developed. The main incenartor frame is made of iron elbow. The iron elbow is cut using an appropriate machine depending on the dimension of the design, and they are assembled by welding process. The furthure step is to complete by manufacturing of the chamber, and chimneys. The wall of he incinerator machine is made of red bricks, and glass woll for insulators. To measure and control the temperature, thermocuple and thermocontrol being put on the inner wall of the incinerator machine are used. The function of the incinerator machine was tested, and it wotked well. Commisioning test of the machine for solid medical waste i.e. infusion bottles, spets, glass bottles, baby pempers and expired medicines were conducted. It shows that the acheived temperature is of 998⁰C during 25 minutes of the opearation and all of the solid waste have become ash except needle, plastic and glass. So, this machine can be operated as a small scale solid medical waste processing equipment.
Simulasi CFD Aliran Stratified Air-Udara pada Pipa Horisontal Sukamta Sukamta; Thoharudin Thoharudin; Dedy Melianto Nugroho
Semesta Teknika Vol 21, No 2 (2018): NOVEMBER 2018
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.212227

Abstract

Two-phase flow can be found in industries, such as petroleum, electricity generation. In geothermal power plants, two-phase flow occurs from a mixture of water and steam which should be avoided in the piping system because it can cause equipment damage in the operating system. Therefore, an operator and engineer need a knowledge of flow patterns, phenomena and characteristics of the two-phase flow. One of the methods to predict the flow pattern is ud\sing the Computational Fluid Dynamic (CFD). This CFD simulation was modeled using Ansys Fluent 15.0 software to determine the changes of Stratified flow characteristics. The model used is Volume of Fluid (VOF). The fluid type is water and air. The variation of superficial water velocity JL of 0.025 m/s - 0.1 m/s while the superficial air velocity (JG) of 0.05 m/s - 1 m/s. The pipe used is an acrylic of 19 mm diameter and length of 1000 mm. The simulation results show that: (1). Stratified flow occurred for the low velocity of the liquid and gas phases. It was shown by the water and air are clearly separated. (2). Flow patterns are not stable, but it can change depending on the superficial velocity of gas and water. (3). The larger of JG causes the wave height because of Bernoulli’s effect so that it will make the stratified wavy or ripple flow pattern. (4). The frequency of stratified-wavy and ripple waves will tend to decrease when the JL increases, while the effect of JG is insignificant. Furthermore, it can be concluded that the speed of gas must be regulated so as not too large to the speed of water.
Pembuatan Alat Uji untuk Mengikat Partikel Logam yang Terkandung dalam Pelumas Akibat Gesekan Mesin Sukamta Sukamta; Sudarja Sudarja; Nurdarojat Nurdarojat; Agung Prasetyo
Semesta Teknika Vol 17, No 2 (2014): NOVEMBER 2014
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v17i2.422

Abstract

One of the factors that can affect to the quality of lubricantion is metal particle content due to friction of engine parts.  Metal particle in lubricanting oil could damage the engine parts, so it is neccessary to reduce the metal particle content which mingled in lubricant oil. The experiment was conducted in laboratory scale using power magnetic type ring neodymium possessing diameter of 19 mm and thickness of 2 mm. The experiment was conducted by flowing the lubricanting oil containing metal particle continually and put the magnets in engine so that the metal particle will be taken up by the magnets. The experiment used  three variations of time (5, 10 and 15 minutes) and three variations of valve to controlling the flow rate using. The highest  absortion of metal  particle was reached on opening valve 30 for 15 minutes. When volume the flow rate was 200 ml/s and the time was 15 minutes  the result of absortion was 7.48 % (magnet A), meanwhile for volume the flow rate 180 ml/s and the time was 15 minutes resulted in particle absortion of about 7.37 % (magnet B). When Magnet A and B used together and at the same flow rate and time, i.e. 180 ml/s time 15 minutes, resulted the particle absortion about 17.98 %.
Pengaruh Diameter Katoda pada Sensitivitas Pengukuran Gradien Kecepatan dengan Metode Polarografi Sukamta Sukamta
Semesta Teknika Vol 11, No 2 (2008): NOVEMBER 2008
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v11i2.762

Abstract

Wall velocity gradient measurement using polarography gives very accurate output due to the absence of problem in fluid flow. Therefore this experiment is highly recommended. Based on the polarogram resulted in the polarography method, the potential that has to be applied to both electrode is 0.25 – 0.75 Volt, whilst in the experiment 0.45 is applied. Calibration has been done to single phase flow, by measuring as a result of  by friction between wall and current flow through electrode at constant flow rate. The ΔP data are used to determine τ. Relation plot between τ (resulted from ΔP measurement) and current can be obtained from the data acquisition device. The result of this research shows that the value of wall shear stress (as velocity gradient) is influenced by the increase of flow rate. Whilst measurement of wall shear stress shows that the cathode area gives effect on the sensitivity of the measurement,  a small cathode results in better shear stress data measurement (more sensitive). In this research the best wall shear stress was resulted in cathode with diameter d=0.2 mm.
Analisis Unjuk Kerja Boiler Feed Pump Turbine Untuk Kapasitas Ketel Uap 2000 Ton/Jam Di PLTU Cirebon Jawa Barat Sukamta Sukamta; Sudarja Sudarja; Muhammad Mujaddid Ighna Wathon
Semesta Teknika Vol 18, No 1 (2015): MEI 2015
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v18i1.702

Abstract

Boiler feed pump turbine (BFPT) has an important role in the circulating of demin water from deaerator to the separator of  steam power plant operations (PLTU) in Cirebon. Flow rate, temperature and  pressure were important parameters in boiler feed pump process. Based on the BFPT function, it was necessary to do the analysis interpretation of the performance BFPT. Data needed for evaluation include pressure and temperature on the suction, pressure and temperature on the discharge, and flow capacity. In this study, the data were taken starting in January to December 2014. Data processing was performed using a centrifugal pump calculations, presented in tables and graphs using MS Excel. Analysis of data using qualitative interpretation of quantitative data. BFPT efficiency during operations in 2014 decreased in February - March amounted to 17.91% (BFPT A) and 18.04% (BFPT B). BFPT A highest efficiency obtained in January amounted to 73.76%, the lowest in March amounted to 55.45%. The highest efficiency BFPT B in February amounted to 72.94%, the lowest in March amounted to 54.9%. Change of Performance BFPT occur due to changes load generator power plant that led to the pressure change  and flow capacity. Other factors that degrade the performance because BFPT was operated continuously for 24 hours and the age of  BFPT sufficient old  cause decrease in pump performance.
Karakteristik Pembakaran Briket Kokas Lokal Pada Beberapa Temperatur Karbonasi Dedet Hermawan Setiabudi; Dwi Aries Himawanto; Sukamta Sukamta
Semesta Teknika Vol 9, No 2 (2006): NOVEMBER 2006
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v9i2.866

Abstract

In order to investigate the better carbonization process that used in foundry application, this research was performed the materials of this research are the local coke that usually used in Ceper Klaten. This local coke was pressed into cylindrical shape and then carbonize in the three variation  carbonized temperature i.e. 100 0C, 200 0C  and 300 0C as long as one hour then taken into furnace to find the combustion characteristics.The result shows that carbonization process has the optimal temperature.
INISIASI PRODUKSI PAKAN LENGKAP SAPI (COMPLETED FEED) BERBASIS LIMBAH PERTANIAN Sutrisno Sutrisno; Triwara Buddhi Satyarini; Sukamta Sukamta
Prosiding Seminar Nasional Program Pengabdian Masyarakat 2018: 2. Penguatan Inovasi Teknologi (Pangan, Pertanian, Energi, Transportasi) Bagi Pemerintah Daera
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (500.208 KB)

Abstract

Kegiatan ini bertujuan mengedukasi petani untuk memanfaatkan limbah pertanian berupa sisatanaman dan pengolahan hasil maupun produksi afkir yang memiliki nilai ekonomi rendah. Limbahpertanian tersebut dimanfaatkan sebagai pengganti pakan lengkap sapi (completed feed : CF)produksi pabrikan (konsentrat) yang selama ini dibeli oleh petani. Produksi pakan lengkap(konsentrat) berbasis limbah berarti peningkatan nilai tambah limbah pertanian. Pada sisi lainproduksi konsentrat secara mandiri ini diharapkan dapat menekan biaya pakan sehinggamendorong usaha peternakan sapi. Kegiatan ini dilakukan dengan metode pemberdayaan berupapeningkatan pengetahuan, ketrampilan dan manajemen produksi sehingga petani memilikikemampuan untuk mengelola proses produksi mulai dari persiapan bahan baku, persiapanperalatan dan mesin, pembuatan konsentrat, uji nutrisi pakan dan perencanaan pemasaran. Hasilakhir kegiatan ini adalah produksi konsentrat sapi berbahan dasar tongkol jagung, kulit kacang,kedelai afkir, gaplek afkir dan dedak padi. Hasil uji laboratorium menunjukkan bahwa konsentrat initelah memiliki nilai nutrisi yang layak bagi sapi setara konsentrat produksi pabrikan. Petani dapatmenghemat biaya sebesar 37 % dibandingkan jika membeli pakan lengkap atau konsentratpabrikan.
Peningkatan Pendapatan Pengrajin melalui Produksi Briket Ramah Lingkungan Sukamta Sukamta; Indardi Indardi
PengabdianMu: Jurnal Ilmiah Pengabdian kepada Masyarakat Vol 6 No 3 (2021): PengabdianMu: Jurnal Ilmiah Pengabdian kepada Masyarakat
Publisher : Institute for Research and Community Services Universitas Muhammadiyah Palangkaraya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33084/pengabdianmu.v6i3.2083

Abstract

The problems faced by coconut shell charcoal craftsmen are production capacity, product quality, and low selling prices. Low product quality is due to the absence of quality standards in the production process. This activity aims to improve the management quality and add value to charcoal products by turning them into briquettes to increase the selling price. Implementing activities is divided into two different problem areas that one partner handles: production problems and management problems (raw material management, production process management, packing, and warehousing management, shipping management, product quality assurance management, and marketing management). The output of this community service activity is that coconut shell charcoal has been produced with an increased quality than before in terms of the low water content of less than 7%. Likewise, the briquettes to those produced are of high quality. There is an increase in added value through processing shell charcoal into briquettes which have significantly increased revenue and profit.