Crane paper, exchanger 5

[Lblopez]

Hi, Where can I find the Crane Technical paper Nº 410?
Thanks

 

[MortenA]

Of course i dont object to exchanging advice here - wheater this is quotes from Crane or any other textbook or not. Im referring to distrubting e.g. photocopies of Crane (or any other textbook) or copies of computersoftware.

I may have misunderstood the question. Even quoting from a limited section seems fine to me instead of buying the whole book just for one paragraph.

Best regards

Morten

 

[Lblopez]

Thanks to everybody. You are the best.

MortenA,

I don´t looking for an illegal copie of Crane or Visual Flow. In my company we have the Process Engineering suites (SimSci-Esscor) License. My trouble is that my company will do not give me money (Here in Venezuela US$ 35 is a considerable amount of money) to buy crane's book only to obtain the K factor to supply Visual Flow requirement.
We have very amount of bibliography of mechanical fluids and they do not will buy another.

Thank you.

LbLópez.

 

[Montemayor]

Lopez:

I understand your situation in Venezuela and I empathize with you. I worked and lived in South America for some years and I am very familiar with what it is like to practice engineering there. However, being a Venezuelan and doing engineering design there may have some benefits unknown to you. I've had 5 copies of Crane's Tech Paper #410 in my 46 years as an engineer - and all of them were received free from pipe and equipment suppliers here in the USA. The last one I got was from Vinson Supply Company, out of Dallas.

I don't know what company you work for, but perhaps if you got together with your purchasing department or buyers you might get an idea if they can obtain some free copies for you through their purchasing contacts either here in the USA or there in Venezuela. There is a lot of fluid flow design being done in Venezuela today; I'm presently working on 2 projects related to projects there. So I'm very familiar with the quantity and size of B31.3, B31.8, and API 5L piping that is going to be installed. There are megatons and megasizes in question and consequently there should be some bargaining or leverage position for you and your engineering buddies there to obtain complementary copies through cooperation with your purchasing department.

Buena Suerte y Exito.

 

[Lblopez]

Thank you Montemayor,

I'm a Junior engineer. I am learning. You're rigth, have some benefits still unknown for me.

 

[Latexman]

Lblopez,

Es un cambiador de calor de la cáscara y del tubo? Está usted interesado en el lado del tubo o el lado de la cáscara?


Good luck,
Latexman

 

[Lblopez]

Latexman,

Is a shell and tube heat exchanger. Really, the cooling water system have many heat exchangers (40 approx).

I have all information that you ask me in your past post, in the heat exchangers data sheet, I did a simulation in HEXTRAN to obtain the pressure drop.

I have the pressure drop in both sides, but I need K factor to Visual Flow simulation. I know that is related with pressure drop but I dont have the equation (formulae)
I'm looking for this K factor. ¿You Know how can I calculate it?

Thank you!

 

[Latexman]

Lblopez,

Did you check the "Help" section of Visual Flow for their definition of K? In their documentation they should have an equation for pressure drop with K defined. If not, call the person in your company that gives technical support for that software or call Visual Flow's technical support or search their website.

If not, EGT01 did an excellent job above. Be careful with units (SI or English)! Different units will change the value of K.

You can estimate the pressure drop (dP) of a heat exchanger with HEXTRAN. Let's say you want to calculate K for the tube side of a particular exchanger. For example, let's say HEXTRAN calculates the dP of the tube side of this particular exchanger at 5 psi. Now you need to take the dP (5 psi) from the heat exchanger evaluation and use it to characterize the heat exchanger as a fitting or pressure drop element in Visual Flow with a K factor. So, use EGT01's equation for K:

K = dP * d^4 / (0.00001799 * rho * Q^2).

dP = 5 psi
d = the inside diameter of the water piping to and from the tube side of this particular exchanger used in Visual Flow
rho = the density of the water to and from the tube side of this particular exchanger used in Visual Flow, lb/ft3
Q = flow of the water to and from the tube side of this particular exchanger used in Visual Flow, gpm

Take the calulated K and use it in Visual Flow.

*IF* the flow and density of the water to and from the tube side of this particular exchanger used in Visual Flow CHANGES as your simulations in Visual Flow approach reality, you'll need to re-calculate a K for the tube side of this particular exchanger. It may take a few iterations to a converged solution.



Good luck,
Latexman

 

[Latexman]

LBlopez,

Be sure you use the correct units in each equation. Convert the values and units of each variable into the correct units for an equation before you substitute it into the equation!


Good luck,
Latexman

 

[srfish]

On 19 Jan you mentioned an "exchanger window". If you meant the shell side baffle window you could retrieve an article by Dale Gulley. It was in the June 2004 issue of Hydrocarbon Processing. The title is "More Accurate Exchanger Shell-Side Pressure Drop Calculations". There is an equation for the K factor for the baffle window.

 

[Lblopez]

Thank you Latexman!

 

[Lblopez]

srfish,

I referred to a window of simulation software.

 

[abeltio]

perhaps i did not understand correctly lblopez...

what i understood is:
1.you did the HE pressure drop calculations...
2.you need a K to use in a flow simulation program

if 1 and 2 are correct interpretations of your problem...

you can calculate a "equivalent" K for your HE doing the following calculation:

K = [Δ]p/([ρ]V^2/2g)

use V corresponding to the pipe diameters connected to the HE...
this will replace the HE with a "virtual length of pipe" that has the same pressure drop as the HE at design conditions...
for small variations of flow (10%~15%), and temperatures this will still give a good approximation.

espero que esto te sirva chamo.

saludos.
a.

 

[XELR8]

Why don't you just install a pressure gage on the inlet to the exchanger and one on the outlet of the exchanger and measure the pressure difference and then calculate the K factor from that measurement.