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Mesin las gesek dengan sistem pneumatik merupakan suatu proses pemesinan dimana dua batang poros digabungkan yang mana nyala las diperoleh akibat dari kombinasi antara gesekan dan tekanan. Dibutuhkan kecepatan dan nilai tekan yang sesuai agar menghasilkan mengasilkan lasan yang sempurna. Metode dalam pembuatan mesin las gesek dengan sistem pneumatik ini dimulai dengan proses perencanaan, pembuatan, perakitan dan pengujian mesin. Tahapan dalam pembuatan mesin las gesek dengan sistem pneuamtik antara lain: menggambar kerja, pemotongan bahan untuk komponen pembuatan sesuai gambar kerja, pengeboran, pembubutan, pengefraisan, pengelasan, perakitan, finishing, analisis seluruh biaya, pengujian kinerja mesin yang dibuat dan pengujian spesimen hasil dari proses mesin las gesek dengan sistem pneumatik. Hasil yang dicapai yaitu mesin las gesek dengan sistem pneumatik berjalan dengan kondisi fungsional yang baik dengan kecepatan putaran maksimum 2800 rpm dan nilai tekanan maksimum 8,5 bar, data tersebut diperoleh dari spesifikasi motor listrik dan actuator pneumatik yang digunakan. Mesin tersebut nantinya dipakai untuk keperluan laboraturium teknik mesin pada Universitas Muria Kudus Dari hasil pengujian spesimen uji stainless steel 304 didapatkan data yaitu pada kecepatan 1820 rpm, nilai tekan 4 bar dan waktu gesek 30 detik, spesimen uji stainless steel 304 berdiameter 10 mm memperoleh hasil yang paling sempurna, terlihat dari lelehan yang dihasilkan serta tidak ada tekstur retak pada lelehannya.

Bahan-bahan yang digunakan di dalam industri sering kali merupakan bahan yang berat maupun berbahaya bagi manusia. Untuk itu diperlukan device untuk membantu lalu lintas distribusi suatu barang industri. Beberapa jenis peralatan material handling yang banyak digunakan di industri antara lain, belt conveyor , chain conveyor, screw conveyor, dan pneumatic conveyor. Melihat pentingnya penyebab jenis material handling yang efektif atau efisien dan aman maka penulis berencana melakukan perancangan alat tubular conveyor.Tubular Conveyor adalah Sistem konveyor kabel tabung yang memindahkan produk dengan lembut, efisien, horizontal dan vertikal di dalam tabung agar terhindar dari debu supaya makanan tetap bersih. Bahan yang diangkut mesin Tubular Conveyor ini adalah padi atau beras, pada umumnya jenis-jenis tubular conveyor ada beberapa bentuk antara lain HVH (Horizontal Vertical Horizontal , U-shape, In-line.Penelitian ini bertujuan untuk merancang Tubular Conveyor dengan sistem berbentuk in-line .Sistem konveyor kabel tabung memindahkan produk dengan lembut, efisien, horizontal dan vertikal dalam tabung kedap debu tanpa degradasi atau deklasifikasi produk. Spesifikasi mesin ini yaitu menggunakan tabung dengan diameter 2,9 inchi atau 73 mm dengan panjang tabung 3 meter dan sistem penggeraknya menggunakan motor listrik dan bahan yang diangkut adalah padi atau beras.Kata Kunci : Material Handling, Tubular Conveyor, Perancangan Conveyor

Gedung Dinas kesehatan Kabupaten Jepara berlokasi di Jl. Kartini No.44, Kauman, Kec. Jepara, Kab. Jepara, Jawa Tengah 59417. Bangunan dua lantai yang mempunyai luas gedung (1033 m) terdiri dari 3 buah panel listrik DKK Luas gedung 283m2 (7700 VA), DKK2 Luas gedung 568 m2 (22000VA), DPRDGR Luas gedung 182 m2 (7700 VA), membutuhkan penataan ruangan yang baik dari segi daya kelistrikan. Metode penelitian yang dipakai adalah audit energi. Dengan adanya penelitian audit energi, dapat diketahui nilai Intensitas Konsumsi Energi (IKE) dan Peluang Hemat Energi (PHE). Dari hasil penelitian audit energi didapat nilai Intensitas Konsumsi Energi (IKE) untuk panel listrik DKK sebesar 66,77 kWh/m2tahun, DKK2 sebesar 56,19 kWh/m2tahun, DPRDGR sebesar 168,65 kWh/m2tahun sesuai satandar IKE ASEAN – USAID tahun 1992 untuk perkantoran 240 kWh/m2/tahun. Peluang Hemat Energi (PHE) yang di dapat sebesar 47.3 kWh/bulan. Kata kunci: Audit Energi, IKE, PHE

The understanding of the interfacial wave structure and its effect to the interfacial friction factor is important to reveal the transition from stratified to the slug flows. However, the available theoretical of models, as well as the correlations to predict the wave interfacial characteristics, is quite rare. The discrepancy among researchers is often found. In the present work, the wave characteristics of air-water stratified flow were investigated experimentally. The inner diameter was 26 mm. The liquid superficial velocity (JL) raised from between 0.02 m/s and 0.075 m/s while the gas superficial velocity (JG) ranged from 4 m/s to 16 m/s. A high speed camera was used to capture high-quality visual data which was later processed with the image processing technique. As a result, the quantitative parameters of the stratified flow were successfully determined and analyzed. Next, the dimensional analysis was carried out to develop correlation to predict the flow parameters of the wave such as the wave frequency, the wave velocity, the wave amplitude, and the wavelength. Furthermore, it is found that the ratio of gas and liquid Reynolds number and Martinelli Parameter plays important role in almost all of the proposed correlation.

Slug flow is the most prevalent problem of two-phase fluid transportation in the petroleum industries. Here, large amplitude waves lead to the pipe blockage that possible to cause the damage of the mechanical structure. The experimental investigation of gas-liquid slug two-phase flow in a horizontal pipe was carried out to investigate the initiation and flow development mechanisms. Air and water were used as the working fluids. The inner pipe diameter was 26 mm. In the present experimental study, the slug initiation mechanisms were explained by visual observation and pressure fluctuations. Moreover, the initiation frequency of slug flow and the evolution of passing slug frequency along the pipeline were also observed by using two high video cameras. As a result, several basic mechanisms of slug flow initiation in a horizontal pipe were clarified. Those were the wave coalescences, the wave growth mechanism, and the large disturbance waves. A flow initiation map was proposed to address those mechanisms. Here, the slug initiation frequency and the passing slug frequency were obtained in relation to the pipe length position. The static pressure measurement was also used to verify the image processing results on the characteristics of slug initiation mechanisms. The obtained qualitative and quantitative results from the investigation can be used to evaluate the recent available models.

Perilaku aliran stratified searah horizontal diteliti secara eksperimental dengan menggunakan metode parallel wire dan visual. Eksperimen dilakukan pada pipa akrilik berdiameter 26 mm dan panjang 9,5 m. Beberapa sub pola aliran stratified yang telah dilaporkan oleh peneliti-peneliti sebelumnya dapat teramati dengan melakukan variasi kecepatan superfisial udara (JG) dari 4 – 20 m/s dan kecepatan superfisial air (JL) dari 0,01 – 0,1 m/s. Ketebalan film cairan diukur dengan menggunakan sensor parallel wire, sementara kecepatan gelombang dihitung berdasarkan waktu delay yang diperoleh dari teknik cross correlation. Dari hasil penelitian disimpulkan bahwa ketebalan rerata film cairan menurun seiring meningkatnya JG, sementara kecepatan gelombang secara umum meningkat dengan meningkatnya JG dan JL.

Proses pengelasan melingkar banyak dijumpai pada proses manufaktur di dunia industri seperti proses pengelasan pada rangka berbentuk pipa, tabung tekan, pipa distribusi dan lain-lain. Pada proses pengelasan melingkar secara manual sering kali ditemukan cacat las karena adanya kesulitan pengelasan pada bidang yang melingkar. Untuk mengatasi permasalahan ini, perlu dibuat alat bantu pemutar benda kerja pada proses pengesahan dan dapat diatur kecepatannya. Tujuan dari penelitian ini adalah melakukan rancang bangun sistem kontrol urutan proses, kecepatan dan ketepatan penghentian proses pengelasan pada proses pengelasan pipa. Metodologi penelitian ini dimulai dengan kajian pustaka, analisa kebutuhan sistem kontrol, desain sistem kontrol, pembuatan dan pengujian alat. Sebagai hasil, peralatan bantu proses pengelasan pada benda kerja yang melingkar telah berhasil dibuat. Beberapa parameter proses manufaktur dapat ditampilkan dalam LCD. Kecepatan pengelasan benda kerja pada tampilan LCD dibandingkan dengan pengujian dengan tacho meter mempunyai persentase kesalahan berturut-turut berkisar 1,5 ~ 1,7% dan 1,75 ~ 2% pada range pengujian antara 860 ~ 400 rpm Kata kunci: kecepatan pengelasan, pengelasan pipa, sistem kontrol

The slug flow phenomena are often encountered in various industrial applications such as petroleum, process, and power plant. The presence of slug flow should be avoided as it causes structural damage due to resonance, corrosion and pipes blast. From the view point of multiphase flow, the understanding of the slug initiation mechanism is very important in pipeline design. This research is conducted using horizontal transparent acrylic pipes with diameters of 50 mm with a variation on the superficial velocity of water between 0,1 m/s and 0,77 m/s and superficial velocity of air between 0,31 m/s and 6,2 m/s. In the present experimental study, the slug initiation mechanisms was explained by visual observation by using high speed video cameras. As the results, the slug flow initiation mechanism were clarified. Furthermore, the proposed of flow initiation map was introduced.

In the operation of horizontal two-phase flow system, stratified flow should be maintained since it provides good key operational factors and pipe construction safety. Recently, the investigations of stratified flow have widely covered various aspects of the flow, such as the liquid hold-up. An image processing technique devotes numerous advantages related to the abilities of non-intrusive measurement and quantitative visualization. The aim of the present work was to implement the image processing technique to study the characteristics of the stratified flow. Here, the observations were conducted in a transparent horizontal pipe with inner diameter of 50 mm. Air and water were used as the working fluid. The liquid superficial velocity (J L ) was between 0.005 m/s to 0.05 m/s while the gas superficial velocity (J G ) was between 0.94 m/s to 6.00 m/s. The data was processed by using the image processing algorithms that have been developed in the previous study. As a result, qualitative and quantitative identifications of each stratified flow patterns (smooth, ripple, and roll) have been carried out by using an image processing technique. The effects of gas and liquid superficial velocities to stratified flow behaviors were also obtained. Moreover, this study proved that the developed algorithm has been successfully implemented in the present stratified flow case. Furthermore, it can be a promising method to be used in other cases of stratified flow and validation of the available CFD simulation models on stratified flow in horizontal pipes.

Slug is one of the most avoided flows in the piping system network. The high pressure fluctuations can cause damage to the pipes. Therefore, prevention of the slug flow is very important. To understand the phenomenon, an experimental study to investigate the pattern of stratified to slug flow transition has been examined. The present work was conducted on a 26 mm diameter acrylic horizontal pipe with the length of 10 m. Air and water are used as working fluids. Visual image capture is done using Phantom Miro M310 High speed camera on L/D 180-210 from inlet. As a supporting visual observation result, CECM method is also used to measure liquid holdup of fluid flow. The onset of slugging mechanism due to change of both gas and liquid superficial velocity will be discussed. As a result, it is found that the slug formation from stratified flow is at least divided into two basic mechanisms. At low gas velocity, the slug stability condition is created by wave growth mechanism. The increase of JG resulted in the increase of aeration and the of the liquid slug length. When the gas velocity is above 3 m/s, wave coalescence and large disturbance waves initiated the onset of slugging. The Increase of JL on the high JG makes the roll waves higher to create a pseudo slug. In addition, it is found that the formation of high aeration slug is seen at JL = 0.3 m/s when JG is maintained at 3.77 m/s.

The Liquid hold-up and the Interfacial Friction Factor on the Air-Water Stratified Two-Phase Flow in a Horizontal Pipe have been experimentally investigated using superficial gas and liquid velocity of 4 – 16 m/s and 0.02 to 0.1 m/s, respectively. The stratified flow is observed on the horizontal acrylic pipe with 26 mm inner diameter and 9 m length. This present work has utilized the various methods of observation: visual observation through high speed video camera, hold up measurement by using CECM, and pressure gradient analysis which is gathered from the Validyne pressure transducer. The pressure gradient and liquid hold-up signal are sent through amplifier than converted into digital signal by Analog to Digital Converter (ADC). As a result, the characteristics of stratified flow is successfully revealed. Furthermore, a new correlation for hold-up which is based on the gas and liquid superficial velocity, and Froude number is proposed. The R2 which reaches 0.971 and the small value of error band (around 30 %) shows that the proposed correlation produce a good performance. Similarly, a new correlation for interfacial friction factor is also proposed which is arranged as a function of liquid hold-up, gas, and liquid Reynolds number. It produces a satisfying performance which is proven by the high value of R2, 0.999. Moreover, the error band between the proposed correlation and the experimental data is quite small, around 5 % on most of all data.

The co-current air-water two-phase stratified flow is desired to occur in the application of pipelines system, such as natural gas gathering, long distance pipelines, and transmission pipelines, because this flow characteristics offers some advantages related to the safety factor of operational condition. The characteristics of pressure drop in stratified flow is considered as one of an important factor in the capital and operation costs for the simultaneous transportation of gas and liquid in various industries. The main objective of this study is to examine the effect of gas and liquid superficial velocities, and pipes diameter on the characteristics of pressure drop air-water two-phase stratified flow. Experiment has been conducted in 26 and 16 mm i.d. acrylic horizontal pipe with length 9.5 m. Air-water flow was recorded 190 D from the inlet using high speed video camera, and pressure difference was measured between 180 D and 210 D from the inlet using validyne pressure transducer. The common parameters such as visualization, pressure gradient signal in time series, probability density function (PDF), and mean of pressure gradient was analyzed. As a result the effect of gas and liquid superficial velocity, and pipes diameter on the characteristics of pressure gradient can be understood.

The two-phase flow application was commonly found in industrial processes, such as oil and gas production in wells, gas and oil pipelines, etc. The characteristic of two-phase flow had various aspects depending on its interfacial behaviour. The interfacial structures of air-water two-phase flow in a horizontal pipe were experimentally investigated by using visualization method with high speed camera. The experiments were conducted in a horizontal two-phase flow facility, total length 10 m pipe made from acrylic with 26 mm ID. To obtain the flow pattern, a total of 132 flow condition were observed. The superficial gas and liquid velocities were set to 0.31 m/s – 20 m/s and 0.016 m/s – 0.77 m/s, respectively.High Speed Camera observation successfully characterized and demonstrated two-phase flow regime in a horizontal pipe. Its also developed flow regime maps. Air-water two-phase flow is characterized by bubble breakup and coalescence in the transition from plug to slug flow. Interfacial instabilities form in stratified to wavy flow, then small waves, larger waves and the droplet entrainment in transition to annular flow. High amplitude wave was required to form the slug flow. This flow pattern maps is a two-phase flow regime transition including stratified flow, plug flow, slug flow, annular flow and sub-regime of each patterns. The influence of superficial velocity of air and water has a significant effect on the flow patterns and sub-regime types.The two-phase flow application was commonly found in industrial processes, such as oil and gas production in wells, gas and oil pipelines, etc. The characteristic of two-phase flow had various aspects depending on its interfacial behaviour. The interfacial structures of air-water two-phase flow in a horizontal pipe were experimentally investigated by using visualization method with high speed camera. The experiments were conducted in a horizontal two-phase flow facility, total length 10 m pipe made from acrylic with 26 mm ID. To obtain the flow pattern, a total of 132 flow condition were observed. The superficial gas and liquid velocities were set to 0.31 m/s – 20 m/s and 0.016 m/s – 0.77 m/s, respectively.High Speed Camera observation successfully characterized and demonstrated two-phase flow regime in a horizontal pipe. Its also developed flow regime maps. Air-water two-phase flow is characterized by bubble breakup and coalescence in the transition from plug to slug flow. Interfacial instabilities form ...

An investigation of the wetted wall fraction of gas-liquid stratified co-current two-phase flow in a horizontal pipe with low liquid loading was carried-out experimentally. The pipe length and the inner pipe diameter were 10 m and 26 mm respectively. The tested fluids were air and water. The superficial water (JL) and air (JG) velocities ranged from (0.02–0.075) m/s and (4–16) m/s respectively. In the experiments, the circumferential liquid film thickness was measured by using developed parallel wire sensor, and verified by the analyzed image of the axial view of the visual observations. At the same time, the pressure gradient and liquid hold-up data were taken in order to determine the interfacial shear stress between gas and liquid. The results indicate that (1) JL and JG significantly affect the interfacial shape of gas and liquid stratified flow in a horizontal pipe, whereas starting from JG = 8 m/s the interfacial shape changes from flat-shaped to concave-shaped interfaces, (2) a new correlation to predict the wetted wall fraction (WWF) of gas-liquid stratified flow in a horizontal pipe was also proposed, and yielded the mean absolute prediction error (MAPE) of 20.6% in comparison with the obtained experimental data from the present study and the available data in open literatures.

The interfacial wave characteristics of stratified air-water two-phase flow in a horizontal pipe were experimentally investigated by using the flush-mounted constant electric current method (CECM) sensors. The experiments were conducted in a horizontal two-phase flow loop 9.5 m long (L) consisting of transparent acrylic pipe of 26 mm i.d. (D). To obtain the stratified flow pattern, the superficial gas and liquid velocities were set to 1.02 – 3.77 m/s and 0.016 – 0.92 m/s, respectively. Several interfacial wave patterns as described by several investigators were identified. The common parameters such as liquid hold-up, probability distribution function, wave velocity and wave frequency were investigated as the function of the liquid and gas flow rates. The interfacial curvature was calculated on the basis of the liquid hold-up data from the CECM sensors and the liquid film thickness data from the image processing technique in the previous work. As a result, it was found that the mean liquid hold-up decreases with the increase of the superficial gas velocity. In the same sub flow pattern, the wave velocity increases as the superficial gas velocity increases. On the other hand, in the two-dimensional wave region, the dominant frequency decreases with the increase of the superficial liquid velocity.