|WikiProject Chemistry||(Rated Start-class, High-importance)|
|WikiProject Energy||(Rated Start-class, High-importance)|
- 1 Half-Life
- 2 steam engines
- 3 Steam, Mist, and Water Vapor
- 4 counter strike source
- 5 wear vs erosion
- 6 Steam invisible?
- 7 Article split into "steam" and "water vapor"
- 8 Clouds
- 9 New steam technology
- 10 the Mist or Gas edit
- 11 Those phase diagrams
- 12 Expansion volume
- 13 Correct use of language
- (heading added later)--Tunheim 15:24, 16 January 2007 (UTC)
Anything about the Valve Half-Life add on here? Mark Richards 22:15, 10 Jun 2004 (UTC)
- Put that in the disambiguation page if you want. 188.8.131.52 22:34, 16 June 2006 (UTC)
"atmospheric engines" use the contraciton of the condensation of steam, not its expansion.
To a physicist there's a fair amount of pseudo-science here - eg power produced by steam - hmm hardly - via steam perhaps. And the reason for the attractiveness of steam as a working medium surely lies in the fact that it's condensible so the pumping power at the cold reservoir temperature cen be very low. There should probably be some link out to the Rankine cycle (eg Zemansky, Heat & Thermodynamics, p224). Linuxlad 23:26, 20 Nov 2004 (UTC)
Er, why isn't steam a 'fluid', please? All the standard texts I was brought up on, treat is in the same classification as air... Linuxlad 19:53, 3 Jun 2005 (UTC)
On abzisse you must have für Entropie kJ/kg K. Now its without Kelvin.--184.108.40.206 09:44, 12 Jun 2005 (UTC)
- Thanks for that, I fixed it
Steam, Mist, and Water Vapor
If I understand correctly, steam is gaseous water and when it mixes with air, it's called water vapor. But the "steam" you see above a pot of boiling water is actually liquid water that has condensed when the steam/vapor hit the cooler air above the pot. IF this is correct... then this paragraph is a little misleading:
- In common speech, steam most often refers to the white mist that condenses above boiling water as the hot vapor ("steam" in the first sense) mixes with the cooler air. After gaseous steam has intermixed with air, it is no longer properly called steam and is instead referred to as water vapor.
That makes it seem like the stuff you see is water vapor instead of condensed, liquid water.
- You're right, and I fixed that. This page seems to have a lot of lying-to-children, but the topic has a both a complicated technical understanding, and a wide set of common ideas. There are a lot of common misconceptions about phases of matter and water. I've tried to fix up this page by putting the simple explanations first and the more complicated ones later. 220.127.116.11 22:34, 16 June 2006 (UTC)
I see that this issue has been brought up before with regard to both this page and the water vapor page, so I'm almost afraid to ask, but I can't help it, so here goes: what the hell is the difference between steam and water vapor? I've wondered this for years, and haven't found the answer here, even after reading both pages and a lot of the discussion on the talk pages. Unfortunately neither page even attempts to answer this oft-posed riddle. Xezlec 20:48, 6 August 2006 (UTC)
I think that below the critical point we talk of vapours (i.e. condensation may be brought about by the application of pressure without needing cooling as well), whereas above the critical point we talk of gases. So I'd refer to the invisible material close to a spout as steam or water vapour (but not gas), and to the white mist as 'condensed steam'. I regard 'steam' as a colloquialism rather than a scientific term. --18.104.22.168 (talk) 16:22, 21 August 2010 (UTC)
- The difference between steam and water vapor is that water vapor is an invisible gas and steam is a visible mist of liquid droplets. :-) — Omegatron 01:15, 26 October 2006 (UTC)
- I believe your definition is incorrect Omegatron.
- Steam is "odourless, invisible gas consisting of vaporized water. It is usually interspersed with minute droplets of water, which gives it a white, cloudy appearance." (Encyclopædia Britannica (EB) on steam). So steam in itself is invisible.
- Water vapor is steam mixed with air or other gases (EB http://search.eb.com/eb/article-9074829)
- What you see when you puff a small cloud from your mouth in cold weather is neither. It is tiny suspended water droplets, and depending on where they are found can be called fog or cloud. I am not aware of a good general term for water droplets suspended in air.
- --Tunheim 15:35, 16 January 2007 (UTC)
- I believe your definition is incorrect Omegatron.
- I realized my above statement was somewhat blunt and categorical. It wasn't meant that way :P (long day...) --Tunheim 15:44, 16 January 2007 (UTC)
It is tiny suspended water droplets, and depending on where they are found can be called fog or cloud. I am not aware of a good general term for water droplets suspended in air.
- I think the word you're looking for is "steam". Definition: "A mist of cooling water vapor." :-) — Omegatron 16:11, 16 January 2007 (UTC)
- My impression is that steam is 100% water while a puff of breath is mainly nitrogen and such does not qualify as steam. Do you have a reference for your definition? --Tunheim 10:57, 8 February 2007 (UTC)
Discussion continued in the "Article split" section. Nurg 04:31, 24 February 2007 (UTC)
counter strike source
Shouldnt there be a direction type page because I was looking for a Steam page as in counter strike source and day of defeat, not this. —The preceding unsigned comment was added by Aushog (talk • contribs) 23:43, 15 December 2006.
I'm no expert on this, but the WP article on erosion is specifically about the action of the weather on geological formations (inc. soil), and hence is not appropriate here. I looked around and found that wear was much closer to the intended meaning, since that article describes the action of both 'solid on solid', but also 'liquid or gas on solid', as intended here.
EdJogg 15:14, 5 January 2007 (UTC)
- Try 'wet steam' and erosion together in Google. Bob aka Linuxlad 20:54, 5 January 2007 (UTC)
I do not dispute that 'erosion' is the correct term to use. However, the WP article on erosion, good as it is, does not mention erosion of metal, only the various geological processes, and therefore is not an appropriate link with regard to steam. (And I should know now, as a result of this discussion I've just spent two hours tidying-up that article! Who'd be a WikiGnome?))
The article on 'wear', which is in a much poorer state, is much closer to the meaning of 'erosion' intended here. However, I think the safest course of action for now is to unlink it entirely...so I'll do just that!
EdJogg 01:50, 6 January 2007 (UTC)
- Well I'd have thought it more logical to disambiguate erosion into the term (often called erosion/corrosion IIRC) as used by engineers for nigh on a hundred years. Bob aka Linuxlad 09:38, 6 January 2007 (UTC)
I agree completely – linking the word to the WP article corrosion (which is an engineering article) would be much more appropriate than erosion (which is a geology article). Please check out both articles and see which you think is more appropriate... ...and if you decide that corrosion is more appropriate, I will not complain! :o)
EdJogg 10:24, 6 January 2007 (UTC)
Uhh, what? Steam is invisible? I was not aware of this.
Edit-Read the part about steam unmixed with air/in a vacuum. Nevermind.
I'm not so sure a picture of a geyser should be on the steam page. Yes, geysers are associated with steam, but the visible cloud shown consists of liquid water droplets that have formed as the water vapor mixes with the cold air, and portrays an incorrect idea of what is happening. -22.214.171.124 03:25, 29 January 2007 (UTC)
Article split into "steam" and "water vapor"
No reason for the split suggestion was given so I removed it. --Tunheim 15:42, 16 January 2007 (UTC)
- The reason given was "the stuff about water vapor doesn't belong here; it already has an article. this article is about the condensed mist". — Omegatron 16:09, 16 January 2007 (UTC)
- Sorry, I didn't see that one. I thought it was common to provide the rationale of a clean up template at the discussion page that the template in use points to. But I'm rather new to Wikipedia. Could you enlighten me on this? --Tunheim 10:51, 8 February 2007 (UTC)
I agree this should not be split. That would just make 2 stubs. Prep111 15:21, 9 February 2007 (UTC)
- The word "steam" has at least 2 meanings. I'm not a physicist or chemist but it seems to me they are:
- H2O as a gas, ie, the molecules are independent. The gas is invisible. This seems to be the scientific and technical use of "steam". Synonymous with "water vapour" and "dry steam".
- H2O as hot droplets of liquid suspended in air and visible. Invisible gas molecules of H2O will also be present. This is the common or popular use. Similar to "wet steam". (Seems to me the difference between wet steam and clouds/fog/mist is just temperature.)
- Maybe the answer is:
- I am not expert in the subject so maybe there is a better arrangement.
- OED has for steam: "6. a. The vapour into which water is converted when heated. In popular language, applied to the visible vapour which floats in the air in the form of a white cloud or mist, and which consists of minute globules or vesicles of liquid water suspended in a mixture of gaseous water and air. (Also sometimes applied to the vapour arising from other liquids when heated.) In modern scientific and technical language, applied only to water in the form of an invisible gas. The invisible ‘steam’, in the modern scientific sense, is, when its temperature is lowered, converted into the white vapour called ‘steam’ in popular language, and this under continued cooling, becomes ‘water’ in the liquid form. dry steam, in Steam-engine working, steam containing no suspended vesicles of water: opposed to wet steam." Nurg 04:31, 24 February 2007 (UTC)
- I've never heard the term "wet steam", but it sounds like a pretty good proposal. — Omegatron 06:17, 24 February 2007 (UTC)
- Referring to the suggested course of action above:
- 'Move info about the gas...' Support and provide a clearer top-of-page link to water vapour
- 'Make steam ..article about hot suspended liquid...' support
'...and rename as wet steam' strong oppose – the fact that 100s of pages link to this one is a consideration, but more important is the general WP principle that pages should have the name most commonly identified with the subject. I can imagine many people searching for 'steam', but very few for 'wet steam'.
- Create a DAB page oppose. Steam (disambiguation) already exists, making 'steam' a DAB page too seems rather unnecessary.
- Steam should include something about 'what steam is' but also cover the practical uses of steam and how it occurs in nature. Water vapour can cover the scientific aspects of the gas. Curiously, this is pretty much the case already. (I checked the two articles AFTER I wrote that, so maybe not much needs to be done after all... :o) )
- EdJogg 10:10, 24 February 2007 (UTC)
- Referring to the suggested course of action above:
- Nurg, the definition you provided from the Oxford English Dictionary (OED) was very enlightening and makes much sense. However, this doesn't fully clarify the situation of steam vs. water vapor. Would you, or someone else with access to the OED, be able to post the definition of water vapor? --Tunheim 12:10, 28 February 2007 (UTC)
- OED: "water-vapour, the invisible aqueous vapour present in the atmosphere" Nurg 03:14, 24 March 2007 (UTC)
Yeah. I agree with EdJogg. A disambig link at the top of the Steam article is sufficient. It is the term most commonly associated with the suspended droplets. — Omegatron 19:29, 28 February 2007 (UTC)
- 'Wet Steam' seems to be causing some confusion. It is a mixture of the liquid and gaseous phases of H2O (necessarily at boiling point). 'Dry Saturated' steam is pure gaseous phase H2O at boiling point, and as such is more of a theoretical concept than something it is easy to make, as steam is likely either to contain some liquid on the one hand or to be superheated on the other, and dry saturated steam exists only on the infinitesimal boundary between the two. For example, a steam engine is described as either 'superheated' or a 'wet steamer'. Bill F 23:07, 28 March 2007 (UTC)
Just want to point out (sorry to belabor the point) that currently, the first paragraph in the steam article states "steam refers to vaporized water. It is a pure, completely invisible gas (for mist see below).", and the words "vaporized water" are a link to the "water vapor" page. The water vapor page then states "Water vapor, also aqueous vapor, is the gas phase of water." This suggests that the two concepts are precisely identical. Can everyone agree that this is incorrect? Xezlec 03:26, 9 April 2007 (UTC)
I am a physicist, and I have to wonder what the hell is wrong with you people. Steam and water vapor are completely distinct. There is no overlap, at all, ever. "Wet steam" is a tautology on the order of "sugary glucose". I have to question the motives and ethical outlook of a group of people who are willing to redefine words in the English language to obfuscate the difference between two different phases of matter. When you have a kettle on the stove, and you can see steam shooting out of it, that's liquid. The water vapor is invisible to the naked eye. --126.96.36.199 03:48, 9 October 2007 (UTC)
- I fail to see what what this discussion has to do with motives and ethical outlook although I have to wonder what the hell is wrong with a Texan physicist who hasn't the courtesy to sign in. Anyway to my knowledge, "wet steam" in common usage is synonymous with saturated steam. --John of Paris 21:35, 9 October 2007 (UTC)
Sheesh there, physicist- no need to get so touchy. Can't you see that while what you are saying is correct, the word "steam" has more than one meaning and usage? That is the essence of the entire controversy. I myself have to question the ethics of someone who shows up to a discussion like this and speaks down to people who, whether he likes it or not, are his peers.
Anyway, I edit and write science books for kids. We use the term water vapor to mean the gaseous form of H2O (the SLG forms being ice, liquid water, water vapor) Since I communicate with children, I explain that the steam they see coming out of the kettle is actually when some of the water vapor condenses in the air and forms tiny droplets. I point out that right at the base of the kettle you dont "see" steam, and that is the water vapor right there. I have to point out however that I have engineer friends who tell me how all elementary and secondary educational publishing is incorrect on this. They "are" physicists as well, and they have a different view of this because of steam tables and the like. TheMetalChick (talk) 15:57, 29 January 2009 (UTC)
I have also always been taught that water vapour is the gas formed when water is heated, and that steam is a suspension of liquid water droplets in air. These definitions were introduced to me at the age of 11 when I started high school, and perpetuated through GCSEs, A-levels, and four years of an engineering degree - but, only in verbal use. The reference tables engineers use in calculating energy transfers made using heated water are called "steam tables", and in this context steam clearly refers to what we were always taught was "water vapour" at least part of the time. There is an ambiguity in this which should be discussed, but my view is that the definitions we were given in school were probably given so consistently in an effort to remove this ambiguity from the terminology.
Having looked at the OED entry for "steam", I would suggest that their definition, being apparently written by non-scientists, and citing no references in the last hundred years or so, might not be as accurate or reflective of the newer attempt in current education to draw a division between "steam" and "water vapour" as it perhaps could be? Perhaps though, the easiest solution from an engineering perspective would be to rename the steam tables and call them "heated water tables" or similar, since they actually refer to water in a variety of states. Redcore4 (talk) 11:36, 19 February 2009 (UTC)
- I hope this doesn't cause more confusion but discussion on Water vapor ("Scientific Discrepancies, Confounding factors and limits of knowledge" section) may indicate that this definition problem is known, and conveniently ignored / side-stepped by many others. A subsection of the Water Vapor article has been completely removed without explanation, the section included the phrase "this remains a particularly tricky and sometimes controversial factor in many fields of science". A lack of citation has been suggested as justification for the non-inclusion. But, surely, citation would be impossible (a bit like trying to prove a negative), if in fact the problem is regularly side-stepped, or put it another way worked around, as long as the results or outcome are good enough, nobody gets concerned, and nobody gets hurt. Except, that is, those trying to understand the subject, those who haven't been told about the work-arounds and fudges and approximations 188.8.131.52 (talk) 19:22, 20 February 2009 (UTC)
Distinction btw "Steam" & "Water vapor" articles is not clear
Would someone be kind enough to explain to me why this is a separate article from water vapor? I understand that "water vapor," i.e. invisible H20 gas, is different from what we know colloquially as "steam," i.e. microscopic liquid droplets of H20 that have accumulated into a white mist that resembles a gas but actually is a liquid. But this article is very confusing. The lede seems to say that steam is water vapor. Perhaps, they are technically the same. But if there are to be two articles, then this one must be about the gas, and the other must be about the accumulation of tiny liquid droplets that resembles gas but actually isn't.
And, if I'm right in this distinction, then it must be made clear in this article's lede. The lede must say something like: "Steam is technically water vapor, but, colloquially, it's actually accumulated droplets of liquid water that form a visible gaseous-looking substance. This article is about the latter, colloquial meaning of 'steam.'" Something like this must be written in the beginning of the introduction to make the distinction between these two articles clear. Cause, as it stands, readers are going to have no clue why articles on gas-form water are split up. I certainly don't understand why -- after all, the intro flat out says "steam is water vapor."
Also, if there are to be two articles, this one must avoid overlapping with the other. In other words, the "steam" article should not talk about steam as water vapor at all, anywhere (reasonably speaking). That's for the "water vapor" article, not this one. Sure, as aforementioned, the intro should state that steam is technically vapor, but that statement should amount to one clause or sentence in that paragraph. And it should make clear that the content of this article isn't at all about steam as water vapor.
I don't know if I'm getting this right. I know I'm coming to this discussion very late, and, therefore, I'm not totally up to speed. So please do inform me of why these three articles have been split up. Thanks. Cheers, ask123 (talk) 04:32, 7 August 2009 (UTC)
I was re-reading the article and noticed that it refers to steam as "invisible." First of all, I don't believe that the word "invisible" is one that is scientifically valid. Something can be "transparent" or "not visible to the naked eye," but that's not the same as being "invisible." Second, and more to the point, the distinction I was thinking of above clearly doesn't apply. Now it seems to me that this article is about "water vapor," and, therefore, I don't see why these articles shouldn't be merged. ask123 (talk) 04:39, 7 August 2009 (UTC)
- No. — Omegatron 22:58, 14 May 2007 (UTC)
- Agreed, no. - HRS IAM 01:58, 30 July 2007 (UTC)
New steam technology
- Perhaps new steam technology (steam production via the blending of methanol and hydrogen peroxide, instead of simple heating) might again propell steam cars. The technology has been produced by Tiancun Xiao and picked up by Oxford Catalysts
- See also: * Oxford Catalysts Portable Steam
- The above comment may well have been a bit of 'self-promotion' on the part of Oxford Catalysts, but for those interested in the subject it is certainly worth a look. The reaction they have discovered is little short of 'magic'!
- Also available from their site is a Press Release (?) apparently written by a freelance science writer. This gives a better idea about the practical applications of this technology. However, I can't help feeling that a spray applicator for domestic cleaning, that operates at room temperature, and produces a jet of steam at 800degC might be a tad dangerous!! (Their website demo video shows steam igniting a piece of paper!!)
- The technology is too new to add anything on this page, but if suitable refs can be found, would be a good addition to the steam page...
- EdJogg 17:14, 4 September 2007 (UTC)
the Mist or Gas edit
I adjusted to convoluted introduction that chose to emphasise the less-common meaning of the term without making it clear that it's actually ambiguous [as per webster dictionary 1913]. It was easy to do this, without resorting to lying-to-children. 184.108.40.206 (talk) 11:08, 31 May 2010 (UTC)
- That's definitely an improvement --Old Moonraker (talk) 12:18, 31 May 2010 (UTC)
Those phase diagrams
The h-s & T-s diagrams are very interesting, but of limited use for ignorant pedestrians without definitions of some of the superimposed curves, if possible right in the associated captions. "X" in particular is obviously important, but no clue is given as to its meaning except that it must be a fraction of something, <100%. Can this be provided somehow, if not in the captions then in the text? thanks -- Wwheaton (talk) 19:57, 2 July 2010 (UTC)
The volume increase when water evaporates is stated as 1600 times but if you do a calculation based on the ideal gas law it works out at 1699.47. Either the 1600 should be a 1700 or there is some reason why there is this disparity and the 1600 figure is a measured property. Also, the 1600 isn't referenced. I think the figure should either be corrected to 1700 or explained. — Preceding unsigned comment added by 220.127.116.11 (talk) 18:56, 24 October 2011 (UTC)
Correct use of language
Is "Steam" really the technical term for "water vapor", and not vice-versa? It would be sane to think that the fact that "steam" is actually vaporized water needs some understanding of science and therefore technical knowledge. It is only a suggestion. --18.104.22.168 (talk) 22:55, 7 June 2013 (UTC)
- "Steam" has something of an implicit nature of not just being water vapour, but also of being at a raised temperature and pressure over atmospheric, whilst vapour is indeed water in gaseous form, but it's also in equilibrium with the normal atmospheric conditions. When only one of these holds, most obviously above a kettle, it's a bit less clear which is more appropriate to use. Andy Dingley (talk) 23:51, 7 June 2013 (UTC)
My understanding of the ambiguity is: 1. "Steam" is used colloquially to mean the white mist you see from a boiling kettle or from your breath on a cold day. It is not vapor, but tiny droplets of condensed liquid water. 2. Physicists and chemists are usually happy for "steam" to be used colloquially in this way, and to prefer the term "water vapor" to mean water in its vapor phase. Water vapor is colorless, and may, but need not, be mixed with other gases. It does not have to be in equilibrium with anything, it is simply the vapor phase of water. 3. Engineers use "steam" to mean water vapor, usually under pressure. This is the source of the confusion, because there are many practical uses of pressured water vapor, so the word is quite widely used in this sense. One might prefer it if engineers didn't use the word like this, but engineers are busy people, and I never met one who would use six syllables where one would suffice. Dezaxa (talk) 15:46, 27 July 2013 (UTC)