32 Research Article International Journal of Thermal Technologies ISSN 2277 - 4114 ©2013 INPRESSCO. All Rights Reserved. Available at http://inpressco.com/category/ijtt Experimental Analysis of Steam Operated Vacuum Pump M. Mareeswaran a* , M.R.Mohammed Abubakkar Siddiq a , A.Kather Batcha a a Department of Mechanical Engineering, M.A.R.College of Engineering and TechnologyViralimalai, Tamil Nadu, India Accepted 24 May 2013, Available online 1June 2013, Vol.3, No.2 (June 2013) Abstract Based on the law of Condensation the vacuum is generated by condensing the steam inside the pressure vessel. The air inside the pressure vessel is removed by injecting the high pressure steam inside the pressure vessel. The pressure is then allowed to cool by forcing the water around the pressure vessel. The vacuum is generated when steam is converted into water. The vacuum is utilized to generate Supersonic velocity in the nozzle based on Bernoulli’s principle. Key Words: Steam, Supersonic, Bernoulli’s Principle, Vacuum pump, Wind Tunnel. 1. Introduction 1 An outline of the early history of vacuum devices (pumps and pressure gauges) is presented, from the first recorded experiments on vacuum in the 1640s to the start of the modern period of vacuum technology when ultrahigh vacuum was introduced in 1950. The first experiments to produce a vacuum were proposed in 1631 by Reneri of Leiden in correspondence with Descartes. The first recorded experiment to produce a vacuum appears to have taken place in about 1641 when Gasparo Berti experimented with a water barometer. The lead tube AB was about 11 meters long, the tube and reservoir were filled with water and the valves G, D, and B were then closed. The valve B was then opened and the water level dropped to L, a vacuum was left in the chamber above L. The experiment was not very convincing since it was assumed that sound would not travel through a vacuum yet a bell M rung in the vacuum space could be clearly heard, the sound was probably transmitted through the supports of the bell. In 1644 Vincenzio Viviani repeated Berti’s experiment using a mercury-filled glass tube which was inverted with its open end in a reservoir of mercury. The experiment was probably planned by Evangelista Toricelli who was credited by earlier historians with performing the famous experiment in 1643. The Toricellian experiments convinced most scholars at the time that a vacuum had been created. This was the time of the dual papacy and the concept of vacuum was still considered anathema, thus it was dangerous to continue experiments on vacuum in M. Mareeswaran is workins as Asst. Prof. and M.R.Mohammed Abubakkar Siddiq and A.Kather Batcha are UG students, *Corresponding author: M. Mareeswaran countries accepting the Roman pope so the experiments were pursued in the reformed countries and in France, where the French pope was inclined to ignore the opinions of the Roman pope. A few years after these initial experiments on vacuum the first vacuum pumps were created by Otto von Guericke the Burgomaster of Magdeburg; this is when the history of vacuum devices begins. In this paper we examine the development of vacuum devices, in particular vacuum pumps and gauges, from 1650 to the start of modern vacuum technology in 1950 when ultrahigh vacuum was first achieved and measured. 1.1 Vacuum for fun and science, the first two centuries, 1650 to 1850 The vacuum pump was one of the six instruments invented in the 17th century that had a profound impact on experimental science, the others were the pendulum clock, the telescope, the thermometer, the barometer and the microscope. Otto von Guericke started work on air-pumps in the 1640s and his work was first reported by Caspar Schott in 1657. Von Guericke’s first two pumps. These pumps were essentially water pumps being worked backwards. In his first experiment in the 1640s he filled a well-caulked wooden barrel with water and two strong men pumped the water out, as air rushed through the pores in the wood into the empty space a noise was heard. In the second experiment he used a large copper sphere attached to the pump; the water was omitted and the air pumped out directly. When most of the air was pumped out the sphere collapsed with a loud noise, von guericke realized that this was caused by atmospheric pressure. A more accurately spherical vessel was made and the experiment was then successful.