Talk:Mass balance

message: Can someone provide a mathematical statement of the conservation of mass, in the form of partial derivatives or some kind of governing equation? Maybe what I'm looking for is a continuity/conservation type of equation. Problem is, I don't know what I don't know! User 202.156.6.54 January 1, 2006
I've added a link to Continuity equation but hesitate to add much in the Mass balance article: I haven't looked to closely, but I think the following equation is still lacking in wikipedia:
 {\partial C_A \over \partial t} + v \nabla C_A = D_{AB} \nabla^2 C_A + R_A
which relates the derivative of substance A ( {\partial C_A \over \partial t} ) with the convection ( v \nabla C_A), the diffusion of substance A in substance B ( D_{AB} \nabla^2 C_A ) and the reaction rate at which substance A is produced ( R_A). I hesitate, not because I think it shouldn't be in wikipedia somewhere, but because I don't know  where to put it. If the equation above is to be included, I think it would be only proper to explain what it means, e.g. how to interprete it in different coordinate systems e.g. the cylindrical
  {\partial C_A \over \partial t} 
+ v_r   {\partial C_A \over \partial r} 
+ v_\theta {1 \over r}  {\partial C_A \over \partial \theta} 
 + v_\phi  {1 \over r \sin\theta }   {\partial C_A \over \partial \phi}
= 
D_{AB} \left( {1 \over r^2}    {\partial \over \partial r}        \left(r^2 {\partial C_A \over \partial r}\right) + {1 \over r^2 \sin \theta } {\partial \over \partial \theta} \left(\sin \theta {\partial C_A \over \partial \theta }\right) + {1 \over r^2 \sin^2 \theta} {\partial^2C_A \over \partial \phi^2}\right) 
+ R_A
one might then continue to explain different simplifications, e.g. steady-state, no convection, etc. How to make this into  a wikipedia entry rather than a wikibook entry is somewhat beyond my imagination though… Saittam Jan 3, 2006 19:14 CET
If you really want a mathematical statement, then a mass balance is a Taylor expansion of mass ignoring all higher orders than the first order derivative (with respect to time) of mass. (Saittam (talk) 21:46, 17 March 2010 (UTC)
thread_title: Mathematical statement of conservation of mass

message: In Petroleum Engineering, the term "Material Balance" represents Volume Balance. It primarily used to estimate volume of Hydrocarbon in-place in the subsurface reservoir. 203.146.126.2 07:05, 18 May 2007 (UTC)
thread_title:  The use of material balance in Petroleum Engineering 

message: Think this article should relate to information on the CSTR itself not modelling work related to the CSTR. I wanted to have something that described the anaerobic CSTR with diagrams of the digester design instead. Think this article should be renamed and or moved with a new article on CSTRs completed--Alex 10:23, 22 October 2007 (UTC)
replies: text: I think this article requires information on mass balance as a concept, as well as its importance in an engineering context. I don't think that the article should be on CSTR modelling nor CSTRs themselves. For modelling and details surely this information should go under the CSTR article. User A1 14:11, 22 October 2007 (UTC)

text: Mass Balance is a much wider reaching topic than its application to CSTRs.  I would oppose the merger, but inclusion of a paragraph discussing its application to CSTRs with a main article link to CSTRs would be good.Thewellman (talk) 05:35, 1 July 2011 (UTC)
thread_title: Merge and comments

message: If aA+bB->cC+dD then rA = a*r − 1 − a*r1  —Preceding unsigned comment added by 129.16.49.113 (talk) 13:35, 18 December 2008 (UTC)
thread_title: rA = r <sub>− 1</sub> − r<sub>1</sub> seems to be wrong, if I'm not misstaken

message: The ice sheet example makes a lot of hidden assumptions and is probably wrong. Some of them are: 
* I would be suprised if the ice is transported only top-bottom. I would assume a mixed mode transport. 
* The snow will surely be compacted under 3km. It is also ice not snow, is it?
* These two alone would make it a mixed-flow, non constant volume thing, which cannot be handled like this.
LGreiner (talk) 12:16, 17 April 2013 (UTC)
thread_title: Ice sheets, probably wrong and to short to be helpful, deleted

message: There is a lot of good information here, but this article is devoid of reference citations.  It shouldn't be difficult to pull reference citations from Perry's or any mass transfer text.  Some more line diagrams would also help.  I'm on a once-through pass of unassessed articles at the moment, but I hope to be back if no-one else picks it up first.Thewellman (talk) 05:35, 1 July 2011 (UTC)
thread_title: Assessment for WikiProject Engineering

message: This page has not been updated in quite some time.  The material is strongly focused on a particular set of physical systems and has limited new material otherwise.  The pages on continuity equation and conservation of mass seem like they should suffice to cover the topic.  The core material here could be moved to those pages, particularly with the addition of a "Mass Balance" section within the conservation of mass page.  The bulk of this page, devoted to wastewater treatment, should either be absorbed by the many pages on that topic, or deleted.  I'm not very familiar with wastewater matters, but a perusal of some of the pages definitely indicates everything here on the topic could have a new, better home there.  Tfocker4 (talk) 15:11, 10 May 2017 (UTC)
thread_title:  Proposed disassembly & merger 

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thread_title:  External links modified (January 2018) 

message: The introduction has a text piece about the human body and how mass balance applies to it. This section is hard to read, due to the inline quotation of sources and the long paragraph, but this may be because English is not my firswt language. I am not sure if it makes sense to have such a specific example right in the introduction. Also, the human body is basically a chemical reactor, so it should not be a "recent" discovery that it is subject to the law of conservation of mass. I am sure these papers cover some reasonable research and they have been put into a misleading context here. Should this information be removed or perhaps be moved to a sub-section a few pages down? --156.67.180.182 (talk) 15:00, 30 July 2021 (UTC)
thread_title:  Awkward Introduction/ Human Body