7 replies to this topic

[IonCube]

I am attaching x2 pages from a book in which mixing & exothermic heats encountered is given as an example. I believe there is an error in calculation which I have annotated in pdf. Can anyone review?

Attached Files

•  Pages from Heat Transfer Applications for the Practicing Engineer.pdf   93.03KB   128 downloads

[breizh]

Hi,

You may want to use the document attached to review your calculation.

Good luck

Breizh 

[IonCube]

@breizh

Thanks, I know the calculation but the procedure I am understanding. The procedure is straightforward & if my understanding is correct there is a typo error in calculation. I just want someone to review it

[breizh]

Hi,

Yes there is a Typo , you should read -110 Btu/lb.

Breizh 

[IonCube]

@breizh

Thank you, your time meant a lot for me. Thanks again

[gigrosia]

@breizh

Thank you, your time meant a lot for me. Thanks again

Calculate the heat, Q, that needs to be transferred to return the mixture to 77 оF 

Mixture - 60% w/w H2SO4

 

enthalpy 60% H2SO4 at 144 oF - (-86)

enthalpy 60% H2SO4 at 77 oF -(-121)

 

Were is the error?

[breizh]

Hi,

No error on the textbook. The confusion comes from the OP showing a 50% solution on the graph instead of 60%. My bad. 

Sorry about that.

 

Another brochure to support (page 13). example with dilution with water.

 

 Breizh

[IonCube]

 

@breizh

Thank you, your time meant a lot for me. Thanks again

Calculate the heat, Q, that needs to be transferred to return the mixture to 77 оF 

Mixture - 60% w/w H2SO4

 

enthalpy 60% H2SO4 at 144 oF - (-86)

enthalpy 60% H2SO4 at 77 oF -(-121)

 

Were is the error?

 

 

Thanks for correcting us. So if I explain it in words: The 60% solution [the final product via mass balance] is assumed to be adiabatically heated [heat comes from dilution] from 77F to 144F

Edited by IonCube, 27 June 2023 - 09:28 AM.