Crane paper, exchanger
Crane paper, exchanger
(OP)
Hi, Where can I find the Crane Technical paper Nº 410?
Thanks
Thanks
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RE: Crane paper, exchanger
Type "crane technical paper 410" in that box. Click the Web radio button and click on "search".
RE: Crane paper, exchanger
Thanks.
RE: Crane paper, exchanger
http://www.cranevalve.com/tech.htm
which provides you the opportunity to buy a copy of the paper.
RE: Crane paper, exchanger
The second hit I got was the reference to the order form page for the paper: http://
TTFN
RE: Crane paper, exchanger
Thanks.
RE: Crane paper, exchanger
TTFN
RE: Crane paper, exchanger
RE: Crane paper, exchanger
Regards
StoneCold
RE: Crane paper, exchanger
Are you really trying to ask "When I'm calculating the pressure drop in a line, what K-value do I use for a heat exchanger?"
If so, the answer is "This is not found in Crane Technical Paper 410, which looks at flow through valves, fittings, and pipe. You would obtain the pressure drop across the heat exchanger from the manuafacturer's data sheet or by doing a separate calculation for pressure drop."
By the way, I recommend spending the money for the Crane manual. It comes in either English or metric units, is reasonably cheap, and is well worth it! Some companies will even pick up the tab for it.
Patricia Lougheed
Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.
RE: Crane paper, exchanger
FYI, there are some useful heat exchanger affinity laws in the GPSA Engineering Data Book under the heat exchanger tab. If you have a spec sheet (or field data) for one set of flow conditions (mass flow, density, viscosity, thermal conductivity, etc), the heat transfer performance and pressure drop can be estimated for other conditions. Relations are given for both the shell and tube side. Some geometry changes (baffle spacing, tube diameter, etc) are accomidated as well. There is even a worked out example. Obviously some judgement on applicability is required (for example if new conditions involve a phase change), but these are still very useful quick calculations.
About all Crane 410 will be useful for relative to exchanger work is as a reference for basic formulas- i.e. once the pressure drop is known at a given flow rate and density, Crane will show you how K can be calculated from your data. Of course due to the nature of heat exchangers, K may not neccessarily be a constant for other operating conditions.
best wishes and good luck,
sshep
RE: Crane paper, exchanger
RE: Crane paper, exchanger
TTFN
RE: Crane paper, exchanger
I'm doing a cooling water system evaluation, becouse there have some troubles. We doing a Visual flow simulation, in the exchanger window, the pakage need a K value wich is assosiated with pressure drop. I dont know how I can calculate this K for make a better simulation. This K factor produce a change in the pressure drop by each change in the flow.
I can do a simulation without use this K but this would be erroneous, becouse I think, that some troubles that have the plant in study, is that the pipeline have a big pressure drop and the water in not come in to the exchanger in High vacuum distillation and Delayed Coker unit.
The Visual Flow's manual say that this K factor equation is reported in the Crane Technical paper 410.
Thanks everybody.
P.D.: Here US$ 35 is a considerable amount of money and I can't buy it.
RE: Crane paper, exchanger
I understand your difficulty. However, having in hand my Crane manual, I still don't have enough information to provide you an answer. There are different formulae and values of K, dependent upon the component. For example, a full bore gate valve has a K of 8fT where fT is the friction factor. However a tapered bore gate valve has an entirely different K, depending on the amount of the taper.
The pressure drop across a heat exchangers (which is how I am interpreting "exchanger" in your posts) is not discussed in Crane. It has values for straight lengths of pipe, both gradual and sudden changes in pipes, and for various types of fittings and valves.
If you are wanting the K value for piping leading up to a heat exchanger (and not across the heat exchanger itself) then you need to get the K value for each length of pipe, each change in pipe diameter, each elbow, tee, valve, etc. This is a considerable amount of work.
I realize that US$ 35 might be a lot of money; however, I question what was spent on the Visual Flow software and how important the results are. If you are wanting more accuracy than just ignoring the K factor completely, then you need to have some basis for the values used. At least try and convince your management that this information is necessary to run the program.
Patricia Lougheed
Please see FAQ731-376 for tips on how to make the best use of the Eng-Tips Forums.
RE: Crane paper, exchanger
Hey, you, with the "asno barato" company!
If you would describe this heat exchanger in detail, and describe the fluid and flow through the side of the heat exchanger you want pressure drop estimates for, we MIGHT be able to help you!
What kind of heat exchanger is it?
Shell and tube? Plate and frame? Other?
Are you interested in the pressure drop in tube side or the shell side?
Is it 1 pass, 2 pass, 4 pass?
Describe the baffles? 20% cut? 25% cut?
Baffle pitch?
How many tubes per pass?
What size O.D. tubes? Wall thickness? I.D.?
Tube length?
What's the fluid? Water?
What's the flow rate?
Inlet T?
Outlet T?
Etc., etc., etc.?
Good luck,
Latexman
RE: Crane paper, exchanger
However i think that many publishing companies have special prices for 3. world countries and sometime the opertunity to buy issues printed with slightly lower quality at significantly reduced prices. This will however require that you investigate this locally.
Best regards
Morten
RE: Crane paper, exchanger
Interesting ethics question. If the Lblopez were to ask for someone to post or e-mail a page of the Crane paper, that would be illegal (easy ethic answer). But if he asks for the K factor for a particular fitting, I don't think that is illegal or unethical.
It is not clear what Lblopez needs yet.
If your collegue across town called on the phone, and asked for the K factor, wouldn't you give it to him? Or would you tell him to go buy his own paper?
RE: Crane paper, exchanger
K = ft*L/D, where ft is the fully turbulent flow friction factor, L is the equivalent length of pipe and D is the pipe diameter (in L units.) If you can approximate the equivalent length and the friction factor and if you know the pipe diameter, you can approximate the K value.
It seems you are looking for an overall K value for the heat exchanger. Perhaps the Wolverine Engineering Data Book II might help, it gives a compressive look at heat exchanger calculations, including pressure drop calculations.
http://www.wlv.com/products/databook/databook.pdf
MortenA,
You raise a good point regarding the distribution of illegal copies of software or books, but I think copyright law (in the US) allows for information shearing within reason:
http:/
RE: Crane paper, exchanger
For a single phase, incompressible fluid, the head loss through a fitting is directly proportional to the flow squared assuming the friction factor does not change appreciably...
dP = f(Q^2)
From Crane's TP410 or any other of your favorite fluid flow references
dP = 0.00001799 * K * rho * Q^2 / d^4
dP = head loss, psi
K = resistance coefficient
rho = density, lb/ft3
Q = flow, gpm
d = inside diameter, inches
Rearranging...
K = dP * d^4 / (0.00001799 * rho * Q^2)
Now you still need to have some data to start with such as the manufacturers's calculation results indicating the pressure drop for the designed flow rate or you will have to perform those calculations yourself unless you can actually measure the pressure drop and flow in the plant.
The only part that remains is the diameter but I would just pick that equal to the piping run where the exchanger is located which allows you to sum the resistance coefficient of the exchanger directly with the piping. Otherwise, the resistance coefficient for a given component in terms of other diameters is related by...
Ka = Kb * (da/db)^4
RE: Crane paper, exchanger
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
RE: Crane paper, exchanger
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.
RE: Crane paper, exchanger
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.
RE: Crane paper, exchanger
I'm a Junior engineer. I am learning. You're rigth, have some benefits still unknown for me.
RE: Crane paper, exchanger
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
RE: Crane paper, exchanger
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!
RE: Crane paper, exchanger
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
RE: Crane paper, exchanger
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
RE: Crane paper, exchanger
RE: Crane paper, exchanger
RE: Crane paper, exchanger
I referred to a window of simulation software.
RE: Crane paper, exchanger
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 = Δp/(ρV^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.
RE: Crane paper, exchanger