Bigget indirect heater

[CLINDU]

Dear Sirs:
What is biggest and ecnomical scale of indirect heater? So far I've seen 10 mm Btu/hr. My customer need 25 mmbtu/hr. I think the size will be too huge to ship.

Clindu

 

[speco]

Clindu,

It depends on the manufacturer and the style of heater. Often, refinery heaters are well over 100 Million BTUs per hour. You might want to check Jack Hardie's webpage for info. It's at

http://www.jehar.com

Speco

 

[CLINDU]

Speco,
thanks for you help, but after I checked the web site. I found all of them are direct heaters. I knew direct heaters can be much large than 10 mm btu/hr, but my question is about the INDIRECT heater. anyway, thank you much.

Clindu

 

[rosbrugh]

clindu,

We can build a 25 mm indirect water bath heater. The size would be approximate 12ft diameter x 40 foot long depending on coil requirements. Give me the particulars and I will size it for you. Sandy

 

[CLINDU]

Rosbrugh,
Thanks a lot. The problem is the heat media is hot oil. The heater is used to heat crude oil from 25 DEG C to 45 DEg. C. And the oil burner will be used.
I think the size will be much large than that, isn't it?
please size it per firetube duty 25MM btu/hr.
Clindu

 

[glorycloud]

If you are truely wanting a indirect fired heater then the bath will be glycol/water mix. The crude oil will flow through the process coil that is immered in the bath. If you will go to mohawkprocess.com
you can see a picture of a indirect heater. I will be happy to provide you a size if you will give me the mass flow rate of the crude oil and the average temp viscosity(API).Also what allowable pressure drop can you handle through the coil?

 

[GenB]

Can you be more specific: some wanttobuild you a glycol-mixandyou are asking for oil, so if you detail your your design will be better.
are you heating the oil in a re-boiler or other heating fired/unfired vessel?
I imaging a fired re-boiler heating theoil and sending the heated oil through a coil/heat exch inside the crude tank/vessel, but it may be different.
If the design get too-big, it can be shipped disassembled or in sections.
Please let us know.
ER

 

[tickle]

Clindu

It seems strange that the client has come to you for heaters and you have come to ENG-TIPS to get a solution instead of having either of you having a search on the internet.

Anyway, 25 MMBTU/hr is 7.5MW. I have designed 10MW indirect fired heaters, and the sizes that rosbrugh mention are not unrealistic. Try

http://www.kccprocess.com,

but there are 100's of other companies out there.

As for shipping size, it all depends on where is has to go. If it is on the coast then it can be lifted straight on to a barge or a ship at the manufacturing site.

Have you considered using a direct fired heater and a pump around system. Have you considered using two off or three off heaters in parallel. These may work out cheaper and offer the client more flexibility.

 

[CLINDU]

thanks, tickle,
I am sorry I did not make the it clearly. The indirect heater is used fire to heat hot oil bath and then heat thick crude in coils. Thus the U is far less than water bath. This why the heater volume needs to be much bigger.

Thanks for your kindly reply.

Clindu

 

[tickle]

Sorry, I did not look at or remember the changes in U and therefore have been a little quick in my response. The heaters I designed were crude heaters and the company I worked for at the time was making two off 10MW crude heaters as well. So talk to one of the wbh/obh designers/manufacturers.

But, you can still use a pump around system, that would increase the heat transfer rate to the heating oil mediumn and crude oil.

Also, I still stand by the investigation of using 50% or 33.3% heaters to keep the cost down(?) and the flexibility up.

 

[glorycloud]

Why are you using a hot oil bath? With a 45deg C outlet on the crude oil, your LMTD is not that bad and the U is better. Using a heat medium oilbath can produce coking of the firetube if the maximum film temperature of the oil is exceeded. Just a word of caution on that matter.

 

[CLINDU]

GLRYCLOUD,
the purpose to use hot oil is to increasing the temp diffrential between bath and crude. Since the crude is very sticky and heavy, this mothed can increase overal U of heat trandfer. If ues water bath, the heat transfer in bath side is not problem, but crude side will controll overall het trafering. To scrifice some heat trander in bath side and increase in crude side, U will be increase a lot.

Thnaks for your comments

CLINDU