Steam Basics 2008 Armstrong International Inc Steam Basics

Steam Basics - Overview • What is Steam? • Why is Steam Used? • How Do We Create Steam? • How Do We Identify Steam Properties? ® “Expect many enjoyable experiences!” David M. Armstrong 2

This Is Not Steam! • Steam is a vapor form of water, and is colorless, tasteless, and odorless ® “Expect many enjoyable experiences!” David M. Armstrong 3

What is Steam Used For? Steam is Used to Transfer Heat Energy From One Location to Another ® “Expect many enjoyable experiences!” David M. Armstrong 4

Why Use Steam We have already developed the equipment and expertise to design and install steam systems for many different applications We have a lot of knowledge concerning steam Steam is an efficient heat transfer medium Steam is easily controlled

How We Create Steam • Steam is created by adding Heat Energy to water. • Heat Energy is expressed in Btu’s. • 1 Btu is the amount of Heat Energy required to raise the temperature of 1 pound of water by 1 F. ® “Expect many enjoyable experiences!” David M. Armstrong 6

How We Create Steam The Heat Energy required to create steam has two forms: Sensible Heat Latent Heat ® “Expect many enjoyable experiences!” David M. Armstrong 7

Heat Energy – Sensible Heat • Sensible Heat is the amount of Heat Energy required to raise the temperature of water from 32°F to the boiling point (saturated liquid) at a given pressure – Sensible Heat raises the temperature of the water and can be sensed with a thermometer ® “Expect many enjoyable experiences!” David M. Armstrong 8

Heat Energy – Sensible Heat O PSIG 212 F. 1 lb. Water HEAT 1 Lb. of Saturated Water at Atmospheric Pressure Contains 180 Btu’s of Sensible Heat ® “Expect many enjoyable experiences!” David M. Armstrong 9

Adding Heat Energy – Sensible Heat 250 F. 15 PSIG HEAT 1 Lb. of Saturated Water at 15 PSIG Contains 218 Btu’s of Sensible Heat ® “Expect many enjoyable experiences!” David M. Armstrong 10

Heat Energy – Sensible Heat 308 F. 60 PSIG 1 Lb. of Saturated Water at 60 PSIG Contains 277 Btu’s of Sensible Heat HEAT ® “Expect many enjoyable experiences!” David M. Armstrong 11

Heat Energy – Latent Heat • Latent Heat is the amount of Heat Energy required to transform water at the boiling point (saturated liquid) to steam – Adding Latent Heat does not raise the temperature – saturated liquid and steam have the same temperature for a given pressure ® “Expect many enjoyable experiences!” David M. Armstrong 12

Adding Heat Energy – Latent Heat O PSIG 212 F. 1 lb. Steam HEAT 1 Lb. of Steam at Atmospheric Pressure Contains 970 Btu’s of Latent Heat ® “Expect many enjoyable experiences!” David M. Armstrong 13

Adding Heat Energy – Latent Heat 250 F. 15 PSIG HEAT 1 Lb. of Steam at 15 PSIG Contains 945 Btu’s of Latent Heat ® “Expect many enjoyable experiences!” David M. Armstrong 14

Adding Heat Energy – Latent Heat 308 F. 60 PSIG 1 Lb. of Steam at 60 PSIG Contains 904 Btu’s of Latent Heat HEAT ® “Expect many enjoyable experiences!” David M. Armstrong 15

What is the Effect of Pressure? Increased Pressure: – Decreases the amount of Latent Heat – Increases the amount of Sensible Heat ® “Expect many enjoyable experiences!” David M. Armstrong 16

What is the Effect of Pressure? 1000 900 800 700 600 500 400 300 200 100 0 0 psig 15 pig 50 psig Latent Heat BTU/lb Sensible Heat BTU/lb ® “Expect many enjoyable experiences!” David M. Armstrong 17

What Is The Effect Of Pressure? • Increased Pressure: – Decreases the Specific Volume ® “Expect many enjoyable experiences!” David M. Armstrong 18

What Is The Effect Of Pressure? • Increased Pressure: – Increases the Steam Temperature ® “Expect many enjoyable experiences!” David M. Armstrong 19

Specific Volume Latent Heat Sensible Heat Steam Temperature Steam Pressure The Pressure / Temperature / Volume Relationship ® “Expect many enjoyable experiences!” David M. Armstrong 20

Identifying Steam Properties Steam Tables ® “Expect many enjoyable experiences!” David M. Armstrong 21

Steam tables allow us to identify all of the important properties of steam, given either the steam temperature or the steam pressure ® “Expect many enjoyable experiences!” David M. Armstrong 22

Example: Steam at 250 o. F is at 15 psig, with 945 Btu’s/lb of Latent Heat Steam at 5 psig is at 228 o. F, with 196 Btu’s/lb of Sensible Heat

Now That We’ve Made Steam What Do We Do With It ® “Expect many enjoyable experiences!” David M. Armstrong 24

Since Steam is used to Transfer Heat Energy From One Location to Another. . . ® “Expect many enjoyable experiences!” David M. Armstrong 25

It only makes sense that we take the heat energy back out and use it to do work. ® “Expect many enjoyable experiences!” David M. Armstrong 26

Removing Latent Heat 1 lb. of Steam at 212 F, with a TOTAL HEAT content of 1150 Btu/lb. – 970 Btu’s of LATENT HEAT = 1 lb. of boiling water (Saturated Liquid) at 212 F with a heat content of 180 BTU’s/lb. 1200 1000 Btu's 970 1150 800 600 400 180 212 200 32 0 212 Atmospheric Pressure ® “Expect many enjoyable experiences!” David M. Armstrong 27

Remember: The Latent Heat added at the boiler is what we have available to do work in our equipment BUT. . . When we remove Latent Heat we create Condensate ® “Expect many enjoyable experiences!” David M. Armstrong 28

Latent Heat can be removed intentionally, in a piece of heat exchange equipment, or unintentionally, from radiation heat loss in piping ® “Expect many enjoyable experiences!” David M. Armstrong 29

What does this Unintentional Heat Loss Mean to your Steam System? Condensate Steam Vapor 50. 3 psig 297. 97 F 100 psig 337. 9 F PRV Trap Trap Vent ® “Expect many enjoyable experiences!” David M. Armstrong 30

It Means: The Steam System is Constantly Being Filled With Water (Condensate) ® “Expect many enjoyable experiences!” David M. Armstrong 31

It Means: Your Steam System is Subject to Corrosion ( CO 2 + H 2 O = H 2 CO 3 ) Subcooled Condensate + CO 2 Forms Carbonic Acid ® “Expect many enjoyable experiences!” David M. Armstrong 32

It Means: Your Steam System is Subject to Water Hammer ® “Expect many enjoyable experiences!” David M. Armstrong 33

It Means: Your Heat Exchange Equipment is Less Efficient ® “Expect many enjoyable experiences!” David M. Armstrong 34

It Means: Your System Must Be Properly Piped ® “Expect many enjoyable experiences!” David M. Armstrong 35

It Means: Your Equipment Must Be Properly Trapped ® “Expect many enjoyable experiences!” David M. Armstrong 36

Armstrong Promise We provide intelligent system solutions that improve utility performance, lower energy consumption, and reduce environmental emissions. . . while providing an “enjoyable experience”! ® “Expect many enjoyable experiences!” David M. Armstrong 37

® “Expect many enjoyable experiences!” David M. Armstrong 38