DASAR – DASAR STEAM TURBINE

PRINSIP KERJA TURBIN UAP

Turbin adalah pengganti sistem penggerak dasar dalam industri dan transportasi laut, di gunakan di daerah operasi yang tidak boleh terkena kontaminasi dari api atau percikkan lonjakan listrik. saat ini penggerak sistem uap sudah banyak tergantikan oleh motor listrik dengan kelas IP anti ledak tetapi di sebagian area tetap di gunakan dengan pertimbangan biaya operasional.

http://en.wikipedia.org/wiki/File:Wirnik_turbiny_parowej_ORP_Wicher.jpg

Dasar yang di gunakan untuk memutar ROTOR turbin adalah Uap bertekanan tinggi di semprotkan melewati nozzle untuk akurasi semburan, pada ROTOR TURBIN terdapat banyak sudu atau blade untuk menahan dorongan dari uap sehingga menimbulkan gaya gerak.

Skema Perjalanan Uap :

 

Gambar di atas adalah sistem turbin chiller

Sistem efisiensi turbin terbagi menjadi dua kelompok, yaitu :

1. Turbin Impulse
2. Turbin Reaksi

Skema Perbedaan Tipe Turbin

Skema diatas menjelaskan perbedaan prinsip penggerak dari turbin yang berbeda tetapi sebagian besar produsen telah menggabungkan sistem tersebut, di bagian tekanan tinggi digunakan sistem Impulse dan di bagian tekanan rendah di gunakan Reaksi agar sistem kerja menjadi berimbang.

besok kita tambah lagi………

Dual Roll Crusher System for Mining application

Roll Crushers are compression type crushers, and were once widely used in mining. They have, within the last 10 or so years, fallen into dis-favor among mining and processing companies. The probable reason is because the large mines require very large crushed product output with minimal cost, makes the roll crusher uncompetitive. The roll crushers are not nearly as productive as cone crushers, with respect to volume, and they do have a little higher maintenance associated with them. Roll crushers do, however, give a very close product size distribution, and if the ore is not too abrasive, they do not have high maintenance costs.

Roll crushers have a theoretical MAXIMUM reduction ratio of 4:1. If a 2 inch particle is fed to the roll crusher the absolute smallest size one could expect from the crusher is 1/2 inch. Roll crushers will only crush material down to a minimum particle size of about 10 Mesh (2 mm). A roll crusher crushes using compression, with two rolls rotating about a shaft, towards the gap between the rolls. The gap between the rolls is set to the size of product desired, with the realization that the largest feed particle can only be 4 times the gap dimension.

The particles are drawn into the gap between the rolls by their rotating motion and a friction angle formed between the rolls and the particle, called the nip angle. The two rolls force the particle between their rotating surface into the ever smaller gap area, and it fractures from the compressive forces presented by the rotating rolls. Some major advantages of roll crushers are they give a very fine product size distribution and they produce very little dust or fines. Rolls crushers are effectively used in minerals crushing where the ores are not too abrasive and they are also used in smaller scale production mining of more abrasive metal ores, such as gold. Coal is probably the largest user of roll crushers, currently, though. Coal plants will use roll crushers, either single roll or double roll, as primary crushers, reducing the ROM coal. Usually, these crushers will have teeth or raised forms on the face of the roll. (Roll crushers used for minerals and metal ores have smooth faced rolls.)

MODERN PUMP

ADVANCE PUMP FOR TODAY ENERGY SAVER…….

Do you need more energy or do you need to lower your cost of electricity payment. Here is solution for you :

Small pump for generate high efficiency water supply to meet your need but no need to pays more electricity cost, compact design and very reliable.

Hydra-Cell Design Advantages

· Positive displacement with smooth low pulse output.

· Heavy-duty industrial construction for long service life in harsh conditions.

· Hydraulically-balanced, unstressed diaphragms.

· Wide range of flow rates from 0.4 to 128 l/min and pressures up to 170 bar.

· Repeatable, accurate output – ideal for metering and dosing.

· Seal-less design – can pump particles in suspension.

· Flexible installation with a variety of mounting configurations.

· Minimal maintenance.  No cups, packings or seals – can even run dry!

· Wide choice of materials of construction for pump heads, diaphragms and valve assemblies..

· High efficiency – low power consumption.

· Compact construction – physically small in relation to performance.

1. Drive shaft - via electric motor, hydraulic motor, belt and pulley etc.

2. Roller bearings - rigid support, immersed in lubricating oil bath.

3. Fixed-angle cam - translates rotary motion into linear to the hydraulic cells.

4. Hydraulic cells - displace diaphragms via pressurised oil.

5. Diaphragms - hydraulically balanced, no stress during flexing.

6. Inlet valve assemblies - simple design, allow liquid into pump chamber.

7. Outlet valve assemblies - allow liquid to flow into pressure discharge line.

8. Pressure regulating valve - controls outlet pressure and prevents pump overload.

Ref : http://www.wannerint.com/Pump+Design

Jogjakarta Earthquake – 07 Sep 2009

 

Gempa telah terjadi lagi di jogjakarta, tetapi tidak seperti tahun 2006, skalanya sekarang ringan dan tidak berpotensi sunami…………….

kenapa akhir akhir ini sering terjadi gempa ?

Kutipan kata KEPSEK BMKG Yogya , Tony A Wijaya :

Gempa tektonik berkekuatan 6,8 Skala Richter (SR) mengguncang sebagian wilayah Daerah Istimewa Yogyakarta (DIY), Senin malam pukul 23:12:24 WIB, dan menyebabkan sebagian warga berlari ke luar rumah untuk menghindari hal-hal yang tidak diinginkan.

Menurut Kepala Seksi Data dan Informasi Stasiun Geofisika Badan Meteorologi, Klimatologi dan Geofisika (BMKG) Yogyakarta Toni A Wijaya di Yogyakarta, Selasa dini hari, gempa tersebut berpusat di laut dengan jarak 253 kilometer tenggara Wonosari, ibukota Kabupaten Gunungkidul, DIY.

Pusat gempa berada pada 10,33 Lintang Selatan - 110,62 Bujur pada kedalaman 35 kilometer.

Menurut dia, gempa tersebut tidak berpotensi tsunami karena berpusat di tengah laut, yang jauh dari pantai.

Ia menjelaskan gempa disebabkan oleh penunjaman lempeng Indoaustralia terhadap lempeng Eurasia.

Guncangan gempa dirasakan oleh sebagian warga di wilayah Kabupaten Bantul, dan Kota Yogyakarta. Sebagian dari mereka berlari ke luar rumah, dan menunggu beberapa saat sebelum kembali masuk ke dalam rumah.

"Di Wonosari sendiri, guncangan gempa tidak begitu terasa karena batuan di wilayah itu lebih padat," katanya.

Oleh karena itu marilah kita merenung sejenak tentang segala sesuatu yang akan kita lakukan di masa mendatang……

pelajaran berharga yang diberikanoleh alam.