Talk:Flow process

created this article

I created this article as a suitable home for some engineering material that was carefully supplied in the past, but I think to an unsuitable home. I am not very interested in this topic, and I hope someone else may like to look after it. This article replaces a redirect page, linked to Process flow diagram.Chjoaygame (talk) 18:00, 9 December 2015 (UTC)

I'm not seeing the relevance of this name to the content added though.

We still need an article for flow processes, in the sense of continual chemical manufacturing processes. That seems a better scope for content at this page title. Andy Dingley (talk) 02:10, 10 December 2015 (UTC)

Thank you for this comment. I moved the material from a section that was headed Flow process. I could see some work had gone into it, and assumed that its originator thought that was a suitable heading. I have no prejudice on the question.

As for its future: be my guest!Chjoaygame (talk) 02:17, 10 December 2015 (UTC)

Presumably from Thermodynamic system#Flow process. It would still seem to be necessary there. Andy Dingley (talk) 02:21, 10 December 2015 (UTC)

Thank you for this comment. With respect, I am not sure that I agree that it is necessary in the article Thermodynamic system. I think it would not be a good idea to extend the scope of that article too far. I read 'thermodynamic system' as a term of classical equilibrium thermodynamics, and perhaps of 'classical non-equilibrium thermodynamics'. Perhaps the material might more suitably have a place in Thermodynamic process? As I read it, its flavor is in the direction that you indicate, towards continual chemical manufacturing processes, rather than the more theoretical one shown in that article. Its approach seems more along practical or engineering lines than theoretical lines. It would be very difficult, I think, to marry the two approaches in one article. Do you think that there is a close connection between 'flow processes' and 'continual chemical manufacturing processes'? Perhaps not?Chjoaygame (talk) 03:06, 10 December 2015 (UTC)

The problem I see is this: Conceptually, it is essential in theoretical equilibrium thermodynamics that the overall motion of the system as a whole is separated from its internal state. Mostly, then, theoretical equilibrium thermodynamics focuses on systems with zero flow internally. For practical engineering, this kind of narrow focus is far too restrictive and gravely lacking in adequate generality. Non-zero flow is essential to flow processes.

It is difficult to fit both approaches into one article. Trying to do so, one has to word every sentence so that almost contradictory viewpoints are both catered for. The wording has to concentrate on contradictions instead of on main lines of thinking.

It is a sad fact that the concept of entropy is not the subject of agreed valid definition outside thermodynamic equilibrium. There are very grave theoretical difficulties in the way of desires for such definitions.

Of course, many optimistic physicists feel 'oh, that's just obsolete pedantry'. Engineers and non-equilibrium thermodynamicists are not on the whole held back by such difficulties. For example, many non-equilibrium thermodynamic approaches happily discuss entropy production as a thermodynamic quantity. Very often this results in excellent approximations. But it is not easy in a Wikipedia article to say in every sentence that 'this sentence applies in one way to pure theory and in a different way to useful approximations'. Ultimately, of course, the facts are the facts, and conceptual difficulties are mere conceptual difficulties: no real contradictions; but not easy to fit into one and the same Wikipedia article.

So I favour separate articles for different approaches.Chjoaygame (talk) 04:44, 10 December 2015 (UTC)

My point is that the content here is Thermodynamic system#Flow process. It is a description of how the concept of a Thermodynamic system is applied to processes with a continuous flow in and out. This is different to an article on bulk chemical production, where ingredients flow continuously through a reaction vessel (the subject described by a process flow diagram), the primary topic being their reaction and the design of the reactor, with their thermodynamic modelling being just a subsidiary section or footnote. Andy Dingley (talk) 10:35, 10 December 2015 (UTC)

Fair enough. Amongst other things, you are indicating that the material is general and somewhat theoretical, as opposed to specifically about an industrial topic. I suppose that is a reason why an article with some title such as perhaps continual chemical manufacturing processes would have this material, if at all, as a subsection or footnote. If someone decides to write such an article, they would exercise their judgement about that. On the other hand, this material doesn't fit easily into an article headed thermodynamic system that seeks to expound the classical theory. This material isn't presented and structured with that purpose in mind, as I read it. As I read it, the present material was originated with an intent to expound as a special topic some particular results that are of some practical interest. If someone wants to exercise his mind and make it clear how it fits with classical thinking, I say let him do so. I think it would take some care to do it. But until then, I think the present material is near enough adequately housed here with the present title.Chjoaygame (talk) 12:05, 10 December 2015 (UTC)