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Steam

February 06, 2023

This article is about water as a gas. For the video game distribution platform, see Steam (service). For other uses, see Steam (disambiguation).

Steam is a substance containing water in the gas phase,[1]: 7  and sometimes also an aerosol of liquid water droplets, or air. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Steam that is saturated or superheated is invisible; however, wet steam or water vapor, a visible mist or aerosol of water droplets, is often referred to as "steam".[1]: 6 

Liquid phase eruption of Castle Geyser in Yellowstone Park
A temperature-versus-entropy diagram for steam
A Mollier enthalpy-versus-entropy diagram for steam

Water increases in volume by 1,700 times at standard temperature and pressure; this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines, which are a sub-group of steam engines. Piston type steam engines played a central role in the Industrial Revolution and modern steam turbines are used to generate more than 80% of the world's electricity. If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapor pressure, it can create a steam explosion.

Types of steam and conversions

Steam is traditionally created by heating a boiler via burning coal and other fuels, but it is also possible to create steam with solar energy.[2][3][4] Water vapor that includes water droplets is described as wet steam. As wet steam is heated further, the droplets evaporate, and at a high enough temperature (which depends on the pressure) all of the water evaporates and the system is in vapor–liquid equilibrium.[5] When steam has reached this equilibrium point, it is referred to as saturated steam.

Superheated steam or live steam is steam at a temperature higher than its boiling point for the pressure, which only occurs when all liquid water has evaporated or has been removed from the system.[6]

Steam tables [7] contain thermodynamic data for water/saturated steam and are often used by engineers and scientists in design and operation of equipment where thermodynamic cycles involving steam are used. Additionally, thermodynamic phase diagrams for water/steam, such as a temperature-entropy diagram or a Mollier diagram shown in this article, may be useful. Steam charts are also used for analysing thermodynamic cycles.

 
 
 
Enthalpy-entropy (h-s) diagram for steam. Pressure-enthalpy (p-h) diagram for steam. Temperature-entropy (T-s) diagram for steam.

Uses

Agricultural

In agriculture, steam is used for soil sterilization to avoid the use of harmful chemical agents and increase soil health.[8]

Domestic

Steam's capacity to transfer heat is also used in the home: for cooking vegetables, steam cleaning of fabric, carpets and flooring, and for heating buildings. In each case, water is heated in a boiler, and the steam carries the energy to a target object. Steam is also used in ironing clothes to add enough humidity with the heat to take wrinkles out and put intentional creases into the clothing.

Electricity generation (and cogeneration)

As of 2000 around 90% of all electricity was generated using steam as the working fluid, nearly all by steam turbines.[9]

In electric generation, steam is typically condensed at the end of its expansion cycle, and returned to the boiler for re-use. However, in cogeneration, steam is piped into buildings through a district heating system to provide heat energy after its use in the electric generation cycle. The world's biggest steam generation system is the New York City steam system, which pumps steam into 100,000 buildings in Manhattan from seven cogeneration plants.[10]

Energy storage

 
Fireless steam locomotive
Despite the resemblance to a boiler, note the lack of a chimney and also how the cylinders are at the cab end, not the chimney end.

In other industrial applications steam is used for energy storage, which is introduced and extracted by heat transfer, usually through pipes. Steam is a capacious reservoir for thermal energy because of water's high heat of vaporization.

Fireless steam locomotives were steam locomotives that operated from a supply of steam stored on board in a large tank resembling a conventional locomotive's boiler. This tank was filled by process steam, as is available in many sorts of large factory, such as paper mills. The locomotive's propulsion used pistons and connecting rods, as for a typical steam locomotive. These locomotives were mostly used in places where there was a risk of fire from a boiler's firebox, but were also used in factories that simply had a plentiful supply of steam to spare.

Mechanical effort

Steam engines and steam turbines use the expansion of steam to drive a piston or turbine to perform mechanical work. The ability to return condensed steam as water-liquid to the boiler at high pressure with relatively little expenditure of pumping power is important. Condensation of steam to water often occurs at the low-pressure end of a steam turbine, since this maximizes the energy efficiency, but such wet-steam conditions must be limited to avoid excessive turbine blade erosion. Engineers use an idealised thermodynamic cycle, the Rankine cycle, to model the behavior of steam engines. Steam turbines are often used in the production of electricity.

Sterilization

An autoclave, which uses steam under pressure, is used in microbiology laboratories and similar environments for sterilization.

Steam, especially dry (highly superheated) steam, may be used for antimicrobial cleaning even to the levels of sterilization. Steam is a non-toxic antimicrobial agent.[11][12]

Steam in piping

Steam is used in piping for utility lines. It is also used in jacketing and tracing of piping to maintain the uniform temperature in pipelines and vessels.

Industrial Processes

Steam is used across multiple industries for its ability to transfer heat to drive chemical reactions, sterilize or disinfect objects and to maintain constant temperatures. In the lumber industry, steam is used in the process of wood bending, killing insects, and increasing plasticity. Steam is used to accentuate drying of concrete especially in prefabricates. Care should be taken since concrete produces heat during hydration and additional heat from the steam could be detrimental to hardening reaction processes of the concrete. In chemical and petrochemical industries, steam is used in various chemical processes as a reactant. Steam cracking of long chain hydrocarbons produces lower molecular weight hydrocarbons for fuel or other chemical applications. Steam reforming produces syngas or hydrogen.

Cleaning

Used in cleaning of fibers and other materials, sometimes in preparation for painting. Steam is also useful in melting hardened grease and oil residues, so it is useful in cleaning kitchen floors and equipment and internal combustion engines and parts. Among the advantages of using steam versus a hot water spray are the facts that steam can operate at higher temperatures and it uses substantially less water per minute.[13]

See also

References

  1. ^ a b "steam". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  2. ^ Taylor, Robert A.; Phelan, Patrick E.; Adrian, Ronald J.; Gunawan, Andrey; Otanicar, Todd P. (2012). "Characterization of light-induced, volumetric steam generation in nanofluids". International Journal of Thermal Sciences. 56: 1–11. doi:10.1016/j.ijthermalsci.2012.01.012.
  3. ^ Taylor, Robert A.; Phelan, Patrick E.; Otanicar, Todd P.; Walker, Chad A.; Nguyen, Monica; Trimble, Steven; Prasher, Ravi (2011). "Applicability of nanofluids in high flux solar collectors". Journal of Renewable and Sustainable Energy. 3 (2): 023104. doi:10.1063/1.3571565. from the original on 2022-12-02. Retrieved 2022-06-14.
  4. ^ Taylor, Robert A.; Phelan, Patrick E.; Otanicar, Todd; Adrian, Ronald J.; Prasher, Ravi S. (2009). "Vapor generation in a nanoparticle liquid suspension using a focused, continuous laser". Applied Physics Letters. 95 (16): 161907. Bibcode:2009ApPhL..95p1907T. doi:10.1063/1.3250174.[permanent dead link]
  5. ^ Singh, R Paul (2001). Introduction to Food Engineering. Academic Press. ISBN 978-0-12-646384-2.[page needed]
  6. ^ "Superheated Steam". Spirax-Sarco Engineering. from the original on 2007-03-04. Retrieved 2009-03-23.
  7. ^ Malhotra, Ashok (2012). Steam Property Tables: Thermodynamic and Transport Properties. ISBN 978-1-479-23026-6.[page needed]
  8. ^ van Loenen, Mariska C.A.; Turbett, Yzanne; Mullins, Chris E.; Feilden, Nigel E.H.; Wilson, Michael J.; Leifert, Carlo; Seel, Wendy E. (2003-11-01). "Low Temperature–Short Duration Steaming of Soil Kills Soil-Borne Pathogens, Nematode Pests and Weeds". European Journal of Plant Pathology. 109 (9): 993–1002. doi:10.1023/B:EJPP.0000003830.49949.34. ISSN 1573-8469. S2CID 34897804. from the original on 2022-04-12. Retrieved 2022-06-14.
  9. ^ Wiser, Wendell H. (2000). "Energy Source Contributions to Electric Power Generation". Energy resources: occurrence, production, conversion, use. Birkhäuser. p. 190. ISBN 978-0-387-98744-6. from the original on 2023-01-23. Retrieved 2016-02-22.
  10. ^ Bevelhymer, Carl (November 10, 2003). "Steam". Gotham Gazette. from the original on January 23, 2023. Retrieved June 14, 2022.
  11. ^ EP Patent Publication 2,091,572
  12. ^ Song, Liyan; Wu, Jianfeng; Xi, Chuanwu (2012). "Biofilms on environmental surfaces: Evaluation of the disinfection efficacy of a novel steam vapor system". American Journal of Infection Control. 40 (10): 926–30. doi:10.1016/j.ajic.2011.11.013. PMID 22418602.
  13. ^ "Why Steam?". Sioux Corporation Website. Sioux Corporation. from the original on 31 December 2017. Retrieved 24 September 2015.

External links

 
Wikimedia Commons has media related to Steam and Water vapor.
 
Look up steam or steamed in Wiktionary, the free dictionary.
 
Wikivoyage has a travel guide for Steam power.
  • Thermophysical Properties of Fluid Systems, Steam Tables & Charts by National Institute of Standards and Technology, NIST

  Wikiversity has steam tables with figures and Matlab code

February 06, 2023
steam, this, article, about, water, video, game, distribution, platform, service, other, uses, disambiguation, substance, containing, water, phase, sometimes, also, aerosol, liquid, water, droplets, this, occur, evaporation, boiling, where, heat, applied, unti. This article is about water as a gas For the video game distribution platform see Steam service For other uses see Steam disambiguation Steam is a substance containing water in the gas phase 1 7 and sometimes also an aerosol of liquid water droplets or air This may occur due to evaporation or due to boiling where heat is applied until water reaches the enthalpy of vaporization Steam that is saturated or superheated is invisible however wet steam or water vapor a visible mist or aerosol of water droplets is often referred to as steam 1 6 Liquid phase eruption of Castle Geyser in Yellowstone Park A temperature versus entropy diagram for steam A Mollier enthalpy versus entropy diagram for steam Water increases in volume by 1 700 times at standard temperature and pressure this change in volume can be converted into mechanical work by steam engines such as reciprocating piston type engines and steam turbines which are a sub group of steam engines Piston type steam engines played a central role in the Industrial Revolution and modern steam turbines are used to generate more than 80 of the world s electricity If liquid water comes in contact with a very hot surface or depressurizes quickly below its vapor pressure it can create a steam explosion Contents 1 Types of steam and conversions 2 Uses 2 1 Agricultural 2 2 Domestic 2 3 Electricity generation and cogeneration 2 4 Energy storage 2 5 Mechanical effort 2 6 Sterilization 2 7 Steam in piping 2 8 Industrial Processes 2 9 Cleaning 3 See also 4 References 5 External linksTypes of steam and conversions EditSteam is traditionally created by heating a boiler via burning coal and other fuels but it is also possible to create steam with solar energy 2 3 4 Water vapor that includes water droplets is described as wet steam As wet steam is heated further the droplets evaporate and at a high enough temperature which depends on the pressure all of the water evaporates and the system is in vapor liquid equilibrium 5 When steam has reached this equilibrium point it is referred to as saturated steam Superheated steam or live steam is steam at a temperature higher than its boiling point for the pressure which only occurs when all liquid water has evaporated or has been removed from the system 6 Steam tables 7 contain thermodynamic data for water saturated steam and are often used by engineers and scientists in design and operation of equipment where thermodynamic cycles involving steam are used Additionally thermodynamic phase diagrams for water steam such as a temperature entropy diagram or a Mollier diagram shown in this article may be useful Steam charts are also used for analysing thermodynamic cycles Enthalpy entropy h s diagram for steam Pressure enthalpy p h diagram for steam Temperature entropy T s diagram for steam Uses EditAgricultural Edit In agriculture steam is used for soil sterilization to avoid the use of harmful chemical agents and increase soil health 8 Domestic Edit Steam s capacity to transfer heat is also used in the home for cooking vegetables steam cleaning of fabric carpets and flooring and for heating buildings In each case water is heated in a boiler and the steam carries the energy to a target object Steam is also used in ironing clothes to add enough humidity with the heat to take wrinkles out and put intentional creases into the clothing Electricity generation and cogeneration Edit As of 2000 around 90 of all electricity was generated using steam as the working fluid nearly all by steam turbines 9 In electric generation steam is typically condensed at the end of its expansion cycle and returned to the boiler for re use However in cogeneration steam is piped into buildings through a district heating system to provide heat energy after its use in the electric generation cycle The world s biggest steam generation system is the New York City steam system which pumps steam into 100 000 buildings in Manhattan from seven cogeneration plants 10 Energy storage Edit Fireless steam locomotiveDespite the resemblance to a boiler note the lack of a chimney and also how the cylinders are at the cab end not the chimney end In other industrial applications steam is used for energy storage which is introduced and extracted by heat transfer usually through pipes Steam is a capacious reservoir for thermal energy because of water s high heat of vaporization Fireless steam locomotives were steam locomotives that operated from a supply of steam stored on board in a large tank resembling a conventional locomotive s boiler This tank was filled by process steam as is available in many sorts of large factory such as paper mills The locomotive s propulsion used pistons and connecting rods as for a typical steam locomotive These locomotives were mostly used in places where there was a risk of fire from a boiler s firebox but were also used in factories that simply had a plentiful supply of steam to spare Mechanical effort Edit Steam engines and steam turbines use the expansion of steam to drive a piston or turbine to perform mechanical work The ability to return condensed steam as water liquid to the boiler at high pressure with relatively little expenditure of pumping power is important Condensation of steam to water often occurs at the low pressure end of a steam turbine since this maximizes the energy efficiency but such wet steam conditions must be limited to avoid excessive turbine blade erosion Engineers use an idealised thermodynamic cycle the Rankine cycle to model the behavior of steam engines Steam turbines are often used in the production of electricity Sterilization Edit An autoclave which uses steam under pressure is used in microbiology laboratories and similar environments for sterilization Steam especially dry highly superheated steam may be used for antimicrobial cleaning even to the levels of sterilization Steam is a non toxic antimicrobial agent 11 12 Steam in piping Edit Steam is used in piping for utility lines It is also used in jacketing and tracing of piping to maintain the uniform temperature in pipelines and vessels Industrial Processes Edit Steam is used across multiple industries for its ability to transfer heat to drive chemical reactions sterilize or disinfect objects and to maintain constant temperatures In the lumber industry steam is used in the process of wood bending killing insects and increasing plasticity Steam is used to accentuate drying of concrete especially in prefabricates Care should be taken since concrete produces heat during hydration and additional heat from the steam could be detrimental to hardening reaction processes of the concrete In chemical and petrochemical industries steam is used in various chemical processes as a reactant Steam cracking of long chain hydrocarbons produces lower molecular weight hydrocarbons for fuel or other chemical applications Steam reforming produces syngas or hydrogen Cleaning Edit Used in cleaning of fibers and other materials sometimes in preparation for painting Steam is also useful in melting hardened grease and oil residues so it is useful in cleaning kitchen floors and equipment and internal combustion engines and parts Among the advantages of using steam versus a hot water spray are the facts that steam can operate at higher temperatures and it uses substantially less water per minute 13 See also EditElectrification Food steamer or steam cooker Geyser geothermally generated steam IAPWS an association that maintains international standard correlations for the thermodynamic properties of steam including IAPWS IF97 for use in industrial simulation and modelling and IAPWS 95 a general purpose and scientific correlation Industrial Revolution Live steam Mass production Nuclear power and power plants use steam to generate electricity Oxyhydrogen Psychrometrics moist air vapor mixtures humidity and air conditioning Steam locomotive Sterilization microbiology References Edit a b steam Oxford English Dictionary Online ed Oxford University Press Subscription or participating institution membership required Taylor Robert A Phelan Patrick E Adrian Ronald J Gunawan Andrey Otanicar Todd P 2012 Characterization of light induced volumetric steam generation in nanofluids International Journal of Thermal Sciences 56 1 11 doi 10 1016 j ijthermalsci 2012 01 012 Taylor Robert A Phelan Patrick E Otanicar Todd P Walker Chad A Nguyen Monica Trimble Steven Prasher Ravi 2011 Applicability of nanofluids in high flux solar collectors Journal of Renewable and Sustainable Energy 3 2 023104 doi 10 1063 1 3571565 Archived from the original on 2022 12 02 Retrieved 2022 06 14 Taylor Robert A Phelan Patrick E Otanicar Todd Adrian Ronald J Prasher Ravi S 2009 Vapor generation in a nanoparticle liquid suspension using a focused continuous laser Applied Physics Letters 95 16 161907 Bibcode 2009ApPhL 95p1907T doi 10 1063 1 3250174 permanent dead link Singh R Paul 2001 Introduction to Food Engineering Academic Press ISBN 978 0 12 646384 2 page needed Superheated Steam Spirax Sarco Engineering Archived from the original on 2007 03 04 Retrieved 2009 03 23 Malhotra Ashok 2012 Steam Property Tables Thermodynamic and Transport Properties ISBN 978 1 479 23026 6 page needed van Loenen Mariska C A Turbett Yzanne Mullins Chris E Feilden Nigel E H Wilson Michael J Leifert Carlo Seel Wendy E 2003 11 01 Low Temperature Short Duration Steaming of Soil Kills Soil Borne Pathogens Nematode Pests and Weeds European Journal of Plant Pathology 109 9 993 1002 doi 10 1023 B EJPP 0000003830 49949 34 ISSN 1573 8469 S2CID 34897804 Archived from the original on 2022 04 12 Retrieved 2022 06 14 Wiser Wendell H 2000 Energy Source Contributions to Electric Power Generation Energy resources occurrence production conversion use Birkhauser p 190 ISBN 978 0 387 98744 6 Archived from the original on 2023 01 23 Retrieved 2016 02 22 Bevelhymer Carl November 10 2003 Steam Gotham Gazette Archived from the original on January 23 2023 Retrieved June 14 2022 EP Patent Publication 2 091 572 Song Liyan Wu Jianfeng Xi Chuanwu 2012 Biofilms on environmental surfaces Evaluation of the disinfection efficacy of a novel steam vapor system American Journal of Infection Control 40 10 926 30 doi 10 1016 j ajic 2011 11 013 PMID 22418602 Why Steam Sioux Corporation Website Sioux Corporation Archived from the original on 31 December 2017 Retrieved 24 September 2015 External links Edit Wikimedia Commons has media related to wbr Steam and wbr Water vapor Look up steam or steamed in Wiktionary the free dictionary Wikivoyage has a travel guide for Steam power Thermophysical Properties of Fluid Systems Steam Tables amp Charts by National Institute of Standards and Technology NIST Wikiversity has steam tables with figures and Matlab code Retrieved from https en wikipedia org w index php title Steam amp oldid 1135296243, wikipedia, wiki, book, books, library,

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