Re: [MW:6221] PWHT of Bigger diameter & Long vessels

Thanks for the inputs.

 

We don't want internal firing to be used. All our suppliers agreed for doing PWHT in enclosed furnace before order.

 

Now they have problems in finding furnces for doing PWHT. We are trying with Cooperheat for their solution.

 

BR

Suresh

On Sat, Jul 31, 2010 at 9:58 PM, Chaitanya Purohit <chaitanya_purohit@yahoo.co.in> wrote:

Its all depends ;
- Experience of person / company responsible (carrying out) PWHT in modular furnace
- Construction of modular furnace (proper and enough insulation to prevent heat loss
- how accurately one can build furnace without any openings / leakage (except opening with damper to control the air flow / exhaust)
- Nos of burner and burner location
- Circulation of hot air (again no of burner and location and blower capacity/position is important)
- Placement and Nos of thermocouple (thin / thick parts will have variation of 20 -80 deg C difference

If all the care taken for the above points then you can considered modular furnace as good as permanent and go ahead without any hesitation.

-  Thickness of part vessel to be heat treated (as the curnace efficiency will not be same as permanent furnace, time to penetrate thickness may take more time (1-1/2 hrs for 30 -50 mm thick material
 

In my opinion, internal firing would be better option with better controls if not much internals (which may hamper the uniform heating).   


Regards.

On 30 July 2010 15:48, suresh venkat <atozsuresh@gmail.com> wrote:

Dear all,

 

we have several equipments of diameter 5mts & above & length 30 mtrs & above. Our specs calls for PWHT in an enclosed furnace.

 

some of our fabricators expressed inability due to furnace size restrictions& informed us that use of Temporary Modular furnaces will pose risk to Quality of final product.

 

I need your advice on the following

 

1. Is doing PWHT in modular furnaces will create any problems to the equipment (in terms of quality)

2. can the temperature be properly controlled

3. Pwht can be performed properly without overheating or Under heating.

 

thanks

 

Suresh

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