Loss of Guide Vane Disposition on Francis Turbine of Unit 6 of the Hydroelectric Power Plant PLTA

Hydropower is a power plant (PLTA) that is very environmentally friendly because it is clean and does not pollute the environment compared to other plants. PLTA, one of which is located in Bengkulu Province, is a power plant that utilizes the potential energy of water. Where the source of the water propulsion produced for the process of generating electricity is from the Tes lake which is sourced from the Air Ketahun river and the Air Pauh river, Lebong Bengkulu. Where this PLTA uses a Francis type turbine with a horizontal position. PLTA has 7 turbine units, with units 1 and 2 being old units producing 2 x 600 KW of power, while units 3 – 7 producing 5 x 4400 KW of power, so the total installed power is 23,200 KW. One of the problems that often occurs in PLTA is the occurrence of disposition of the guide vane on the turbine, where this time we will find out the cause of the disposition and how to overcome it so that there is no disposition and find out the loss of disposition of the guide vane on the Francis unit 6 turbine at PLTA. With this research done, the disposition occurs, it is necessary to take corrective action so that the unit will stop operating and can affect the level of profitability of the company. So that the results of the unit's work if it operates 24 hours are approximately 82 million rupiah, repairs are carried out for 16 hours with a loss of approximately 55 million rupiah. The occurrence of disposition is caused by damage to the transrack so that large waste enters the turbine section. In order to prevent disposition, it is necessary to repair or replace the transrack at the inlet

PENGUKURAN KESALAHAN GERAK SUMBU X DAN SUMBU Z BERDASARKAN HASIL CUTTING TEST MESIN BUBUT CNC INOVASI MENGGUNAKAN COORDINATE MEASURING MACHINE (CMM)

The innovation CNC lathe is one of the machine tools with two axis. The X and Y axis are very influential in producing precision products the axis on the lathe because the axis on the lathe is as a tool for driving the chisel. To determine the precision or not of the motion of the axis, it is necessary to do a cutting test (Cutting Test) then the results of the cutting test are measured for precision using a Coordinate Measuring Machine (CMM). In the cutting test, the ISO 13041-6-M4 Series is used. In this cutting test, a radius of 50 mm is used, the test object can be reused, but the programmed radius should not be more than ± 10% of the nominal radius. The circle deviation tolerance is 0.025 mm. From the measurements made, the largest error value is 1.825056 mm in the first measurement in the CW direction, while the smallest error value is 1.824025 mm in the three-way CCW measurement, the resulting deviation continues to increase along with the cutting direction. The magnitude of the deviation, and the motion between the X-axis and the Z-axis are not collaborating with each other and not constant. This is because from the starting point of the cut on the X axis to the Z axis the deviation is getting bigger. resulting in inaccurate results from the cutting test. From the cutting test and measurements made, it can be concluded that it is necessary to make improvements to the Z axis motion

CHARACTERIZATION OF WASTE PET POWDER AS ATOMIZATION PRODUCT

A nozzle of diameter 25 cm of a closed coupled type was set at an outlet gap 0,05 mm to atomize polyethylene terephthalate plastic wastes. Parameters of pressure and heating temperature were varied into 5 bar, 6 bar and 7 bar pressures, and at 275?C, 285?C and 295?C heating. A vessel to collect the product was 40 cm diametrally away from the nozzle mouth. The products were the form of powders, yarn and liquid. The powders were only 4,77%, 6,45% and 2,94% of each heating temperature aforementioned

PENYIAPAN PROSEDUR PENGUJIAN METALOGRAFI DENGAN MESIN POLES YANG DIBUAT UNTUK LABORATORIUM MATERIAL DAN METALURGI TEKNIK MESIN UNIVERSITAS BENGKULU

Di Laboratorium Material dan Metalurgi Teknik Mesin Universitas Bengkulu, telah dibuat mesin poles (polishing machine) untuk persiapan sampel bagi pengujian metalografi. Pembuatan mesin poles yang baik memberi hasil yang mendekati uji metalografi standar. Sebelum dioperasikan untuk fungsinya, prosedur yang sesuai dengan keterbatasan alat perlu dipersiapkan, sehingga penggunaanya dapat memberikan hasil yang standar sebagaimana fungsi yang diharapkan. Prosedur persiapan sampel pengujian metalografi meliputi pemotongan, pembingkaian, pengamplasan, pemolesan dan pengetsaan. Pemotongan sampel menggunakan pemotongan manual (gergaji besi) ukuran 18 jumlah gigi per inchi dengan tebal tiap sampel 25 mm kecepatan potong sekitar 40-50 strok/menit, divariasikan pada pendinginan air dengan direndam, dialiri dan tanpa pendinginan. Selanjutnya, analisis kualitatif dan kuantitatif. Metalografi kualitatif adalah membandingkan struktur mikro hasil pengujian dengan struktur mikro dari literatur untuk jenis material yang sama yaitu AISI 1045. Sedangkan metalografi kuantitatif adalah menghitung fraksi fasa ferit yang diberikan dari proses annealing dan normalizing menggunakan analisis fraksi volume dan analisis Image J untuk menganalisis kadar karbon. Gambar yang diperoleh melalui pembesaran mikroskop metalurgi 100X di atas spesimen yang dietsa dengan nital 2% memberi karakter yang sebanding dengan gambar standar. Analisis kadar karbon dari fasa ferit mendekati yang dilaporkan dalam material data sheet. Variasi cara pemotongan tidak menunjukkan perbedaan pada struktur mikro yang diamati

Recent progress on hydroxyapatite-based dense biomaterials for load bearing bone substitutes

Hydroxyapatite (HA) is the main mineral component of bone tissue, representing ca. 69 vol% in bone and up to 98 vol% in dental enamel. Its chemical composition close to the mineral phase of bone is the origin of its excellent biocompatibility to tissue bone. Hydroxyapatite has been applied in orthopaedics as block implants, porous, granules and coating material, either dense or porous. However, the application is restricted to non-load bearing application due to its brittleness and low toughness and flexural strength. With this, the development of bioactive dense HA is necessary as it has promising potential in application of load bearing bone implant. Few efforts have been made in developing many methods to produce dense HA. Some of the methods have been combined to prepare dense HA with improved properties. This paper will be discussing the recent progress on efforts which have been done in improving mechanical properties of hydroxyapatite-based dense type biomaterials for load bearing bone substitutes applications. Some recent patents related to dense calcium phosphate are also reviewed

RANCANG BANGUN MESIN POLES METALOGRAFI

Metalografi merupakan pengujian untuk melihat struktur mikro suatu logam dengan menggunakan mikroskop optik, untuk dapat mengetahui sifat logam itu sendiri. Dalam tahapan persiapan spesimen metalografi proses grinding dan polishing merupakan proses yang sangat penting untuk membuat permukaan sampel bahan menjadi benar-benar halus agar dapat dilakukan observasi. Mesin poles yang terdapat diluar memiliki harga yang mahal, untuk itu tugas akhir kali ini bertujuan untuk mendapatkan mesin poles yang murah dan optimal. Mmesin poles ini memiliki satu cakra logam, pengatur putarandan sistem pendingin. Perancangan mesin poles metalografi ini didahului dengan study lapangan terkait dengan prosedur komersial, pemilihan bahan, proses atau analisa morfologi sistem. Kegiatan tersebut meliputi pemilihan-pemilihan berupa kapasitas, dimensi, material, proses pembuatan sistem transmisi, pengaturan kelistrikan dan pendinginan air. Dari kegiatan tersebut diteapkan pemilihan dimensi 410 x 310 x 300 (mm), bahan baja profil siku 40 x 40 (mm), disambung dengan pengelasan sehingga menjadi dudukan bagi cakra baja AISI 1018 berdimensi diameter 200 x 4 (mm) di putar oleh motor Ac satu fasa model XD 330 matrik 50 Hz, dengan pengatur kecepatan yang di transmisikan menggunakan v-belt A-26 pulley diameter 1,5 inch dan 3 inch, analisa pengamatan gaya dengan metode elemen hingga terhadap bahan uji tersebut dapat dibebani sesuai dengan spesifikasi kekuatan mekanik materialny

Teknik Sortir Produk Pangan menggunakan Teknik Bio-impedansi

ABSTRAKKarakterisasi untuk memisahkan mutu-mutu yang berbeda dalam aplikasi industri dapat dipenuhi dengan menggunakan alat dengan kemampuan yang terbatas. Teknik sortir memanfaatkan sistem papan evaluasi Eval AD5933 EBZ berakurasi 0,5% dilakukan terhadap pisang kepok (musa spp) hasil perkebunan di Pulau Enggano, Provinsi Bengkulu. Sistem dinyalakan dengan sambungan listrik bertegangan 2,7 V – 5,5 V mengeksitasi gelombang dari frekuensi 4000 Hz sampai 100.000 Hz kepada tiga sampel, masing-masing tiga kali sapuan. Tanpa ada modifikasi yang diberikan, sistem mampu membedakan impedansi musa spp antara jenis-jenis mutu mentah, mengkal dan masak melalui diagram Argand yang digambar dari data impedansi masing-masing. Diagram Argand yang dihasilkan menunjukkan jenis mutu masak dari musa spp lebih besar (dalam Ohm) dari jenisj-jenis mutu di bawahnya. Sistem ini dapat membantu industri pembuatan tepung pisang yang memerlukan pemilahan jenis bahan baku bermutu tertentu. Kata kunci: sortir, mutu, buah pisang kepok, impedansi ABSTRACTCharacterization to sortir different qualities in industrial applications can be fulfilled by using a tool with limited capability. Sorting technique using a 0.5% accuracy Eval AD5933 EBZ evaluation board system has been carried out on kepok banana (musa spp) from the plantation of Enggano Island, Bengkulu province. The system powered by a 2.7 V – 5.5 V DC low-voltage excited waves from 4000 Hz to 100,000 Hz frequencies to three samples, three sweeps of each. Without any modification, the system has been able to segregate different quality types of unripe, almost ripe and ripe from their Argand diagram drawn from their impedance data. The Argand diagram characterizes that the quality type of banana ripe is more expanded (in Ohm) than the other quality types of below. The system is applicable for a banana flour manufacturing industry that requires the sorting of certain types of quality raw materials.Keywords: sorting, quality, musa banana, impedanc

Kaji sifat fisik biokomposit polylactic acid berpenguat serbuk cangkang kerang lokan

This research aimed to investigate the effect of adding lokan clam shell powder on the physical properties of polylactic acid (PLA) biocomposites. The research materials consisted of lokan clam shells obtained from the fish auction place in Pulau Baai of Bengkulu City, PLA in filament form, and chloroform. Lokan clam shells were washed with clean water, dried for 12 hours and heated at 900oC for 6 hours. The powder obtained was filtered using a 100 mesh sieve. The PLA dissolution process used chloroform for 2 hours in a closed process with a ratio of 1 g PLA to 5 ml chloroform. After that, added lokan clam shell powder and stirred for 15 minutes using a hotplate at room temperature. The biocomposite manufacturing process used a molding technique with variations in the volume fraction of lokan clam shell powder of 10%, 30% and 50%. The physical properties test includes the density test using the ASTM standard of D1622 and the water absorption test using the ASTM standard of D 570. The results of the physical properties research show that the addition of 10% lokan shell powder to the PLA biocomposite is able to reduce the density and increase the maximum water absorption by 0 .89 g/cm3 and 5.91% respectively