Vapor heat

[Freddy Martinez]

Has anyone ever tried or heard of the use of superheated steam to preheat a Coke drum rather than the standard “vapor heat”.

[Anonymous]

i have MP steam at 14 kg/cm2f and 290 deg C. Would like to use the same for preheating of empty coke chamber prior to feed in to a temperature of about 260 deg C.
Aim is to recover the hydrocarbon used for conventional vapor heating and thereby increase the liquid yield. Views solicited.

[Claus Graf]

In the last coker I worked, we only used steam to warm up an empty coke drum for start-up. While running, we would warm the empty drum with the hot vapors of the “coking” drum.
 
I’m guessing here, but your coker probably doesn’t have a “coke condensate drum”. This is where we would recover the hydrocarbon liquids from the drum being warmed. From this drum, we would then pump the liquids back to the fractionator, entering below the heavy coker gas oil draw pan and above the the sheds.
 
Regards
 
CG

[SURAJIT ROY]

Thanks for your prompt response.
We do have coke condensate drum followed by a blowdown tower and blowdown settling drum. My idea is to introduce steam at a controlled rate thru the drum bottom section and route the same from the top (via drain between SP 4 and SP 8 – Foster Wheeler design) to the Blowdown Settling Drum which has been provided with Air Cooler. The steam condensate from the coke settling drum may be pumped to coke cutting water tank for reuse/ top up. I am not sure about the heating rate of the drum as compared to the normal vapour heating and any disadvantages as I am new to this idea. View solicited please.

[Anonymous]

Yes this can be done but it will have the following difficulties,
 1.To line up the coke drum in blowdown tower with MP steam (14 Kg/cm2 g pressure) any mis-operation can lead to pop up the PSV of coke drum.
 2.If the PSV’s lined up to fractionator then it can upsate the fractionator.
 3.This will also generate the more sour water treatment of this will be another headach.
 
I hope this will clarify the issues.
 
 

[Author]

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