9 replies to this topic

[smrtchemengg]

Dear all

 

does have any notes or information regarding cooling of reactors using liquid nitrogen usually called cryo cooling . a process diagram of it would be helpful.

thanks in advance

smrtchemengg

[curious_cat]

What's your application? Size? Temperatures? What sort of reaction is this. 

[thorium90]

More information required. Reactions occur better at higher temperature. Even if they were exothermic, there would come a point where if it was too cold, the reaction just wouldnt happen. Some experimental reactor whose components react cryogenically?

[smrtchemengg]

sir 

 

sorry for the incomplete question. my area is related to industrial services during shutdown operations. the idea is cleaning various exothermic reactors used in petrochemical industry, before cleaning the reactors have to be brought down to normal conditions.it has been found it can also be done using liquid nitrogen for quicker cooling . but i could not find any data related to it . if possible please share.

 

thanks 

[thorium90]

Why would you want to place undue thermal stress on the reactor by quenching it from hot temperatures to room temperatures using liquid nitrogen? That's even assuming your reactor can take that kind of low temperatures? A gradual controlled cooling is definitely the way to go and not the way you suggested.

[smrtchemengg]

sir 

In steel industry they use a process called dry quenching especially in coke cooling section. i thought if this is used instead of traditional method in reactor cooling during shutdown, we provide a better safer environment for working and earlier cooling.

Edited by smrtchemengg, 10 October 2013 - 08:45 AM.

[curious_cat]

Why would you want to place undue thermal stress on the reactor by quenching it from hot temperatures to room temperatures using liquid nitrogen? That's even assuming your reactor can take that kind of low temperatures? A gradual controlled cooling is definitely the way to go and not the way you suggested.

 

@thorium: That was exactly my first impression too. But it seems quite a few (reputable) companies out there advertise a similar solution. 

 

Never used it myself though. Sounds wacky. Wonder how they deal with brittle MOCs, thermal shock, spalling, expansion etc. 

 

http://www.airproduc...or-cooldown.htm

 

http://www.buchen-ic....php?id=488&L=1

 

http://www.halliburt...plications.page

[Bobby Strain]

I encountered this in the mid '80s with Shell. They used liquid nitrogen to inject into circulating gas to cool a hydrocracker. Never got to the details, 'cause I wanted nothing to do with it.

 

Bobby

[curious_cat]

I encountered this in the mid '80s with Shell. They used liquid nitrogen to inject into circulating gas to cool a hydrocracker. Never got to the details, 'cause I wanted nothing to do with it.

 

Ha! So this has been around for a while, eh? Wonder how much time it saves that makes it worth it.

 

How long does a hydrocracker take to cool conventionally? 

[smrtchemengg]

thank you very much sir....(curious_cat) for the information.

any details or process diagrams is welcome. please can anyone provide the step by step safety procedure for cooling of reactor by air. the one used in petroleum industry where venting and removal of toxic substances is required. if possible please upload in pdf format.

thanks in advance.