Steam Engines

By: Michael May

Introduction

• A heat engine that uses steam to perform mechanical work

• Uses:– Stationary: rotary motion to

power machinery in places such as factories

– Transport: Steamboat, steam locomotive, steam tractor, steam car, steam shovel, etc.

History

• first practical steam-powered engine was a water pump

– Thomas Savery 1698

• first commercially successful engine

– Atmospheric engine, Thomas Newcomen 1712

– Paved way for industrial revolution

– Only pumped water, not efficient

– Used to drain mines

Watts Engine

• James Watt• 75% less coal than

Newcomen’s engine• Allowed factories to

move away from rivers

• Accelerated the industrial revolution

Pressure Steam Engines

• 1800 by Richard Trevithick

• Much more powerful

• Relied on high-pressure steam rather than a vacuum.

• Dominant source of power well into the 20th century

Components

• Two major components• Boiler

– Pressure vessels that contain water to be boiled– Mechanisms to transfer heat to water

• Water tube boiler• Fire tube boiler

• Motor– takes a supply of steam at high pressure and

temperature and gives out a supply of steam at lower pressure and temperature

– difference in steam energy to do mechanical work.

How They Work

• Fuel is burned in a firebox to obtain heat

• Heat is transferred to water in a pressurized boiler to produce steam

• Steam is transferred to the motor unit which drives pistons or turbines to power machinery or generators

• Used, cooler air is exhausted

Reference

• http://en.wikipedia.org/wiki/Steam_engine

• http://images.google.com/images?hl=en&q=steam+engine&gbv=2

• http://inventors.about.com/library/inventors/blsteamengine.htm

• http://www.howstuffworks.com/steam.htm

Questions?

Michael May