5 replies to this topic

[Root]

Hi All,

what is happening in my Naphtha splitter column during day time operation, COT is less than the inlet temp approximately 10^0C.
Problem:
During time operational requirement, we need to start some additional air fan coolers and the moment air fan cooler is started reflux flow increase only 3~4m^3/ hr and receiver temp decrease only 4^0C but significantly chang is coming in COT, 'ie' 10^0c less than the heater inlet. Column bottom is the feed of Reformar plant.
other information are here;
Receiver temp/ pressre=64 ^0C/ 0.7 barg.
Column top temp/ pressure= 80^0C/ 1.2 barg
Number of trays: 40 Sieve
Feed tray and temp: 20 @ 167^0C
Btm temp/ pressure: 149^0C/ 1.4 barg
Reflux flow: 90~ 105 on tray 1
Gas fired Heater COT: 156
trya 28 Temp: Design 124 and normal operating 122~124^0C
Heater out let pipe:16" and tehn 24" near clumn about 3~4 meter.
NRV:no, only on pump discharge.
Any comments and suggestion are highly appreiciated.
Thanks
Toor

[Root]

Hi All,

what is happening in my Naphtha splitter column during day time operation, COT is less than the inlet temp approximately 10^0C.
Problem:
During time operational requirement, we need to start some additional air fan coolers and the moment air fan cooler is started reflux flow increase only 3~4m^3/ hr and receiver temp decrease only 4^0C but significantly chang is coming in COT, 'ie' 10^0c less than the heater inlet. Column bottom is the feed of Reformar plant.
other information are here;
Receiver temp/ pressre=64 ^0C/ 0.7 barg.
Column top temp/ pressure= 80^0C/ 1.2 barg
Number of trays: 40 Sieve
Feed tray and temp: 20 @ 167^0C
Btm temp/ pressure: 149^0C/ 1.4 barg
Reflux flow: 90~ 105 on tray 1
Gas fired Heater COT: 156
trya 28 Temp: Design 124 and normal operating 122~124^0C
Heater out let pipe:16" and tehn 24" near clumn about 3~4 meter.
NRV:no, only on pump discharge.
Any comments and suggestion are highly appreiciated.
Thanks
Toor

Hi Art and an other seniors,
Could please shed some light on this problem.
Thanks
Toor

[Padmakar Katre]

Dear,
Please upload the scheme drawing with the parameters like temp,press and flow. Please give the Heater outlet pressure as well as the column feed tray pressure. The design and the opertaing parameters of heater will be more helpful analyse the issue. Waiting for your reply.

[Zauberberg]

It's hard to give any comments without having detailed information about design/operating parameters (at least upload the sketch with design vs. current values).

I have seen similar things in two cases: excessive pressure drop through the heater, or introduction of significant amounts of water together with the heater feed. Both factors induce excessive vaporization inside heater, which lowers the outlet temperature.

[Root]

Hi All,

what is happening in my Naphtha splitter column during day time operation, COT is less than the inlet temp approximately 10^0C.
Problem:
During time operational requirement, we need to start some additional air fan coolers and the moment air fan cooler is started reflux flow increase only 3~4m^3/ hr and receiver temp decrease only 4^0C but significantly chang is coming in COT, 'ie' 10^0c less than the heater inlet. Column bottom is the feed of Reformar plant.
other information are here;
Receiver temp/ pressre=64 ^0C/ 0.7 barg.
Column top temp/ pressure= 80^0C/ 1.2 barg
Number of trays: 40 Sieve
Feed tray and temp: 20 @ 167^0C
Btm temp/ pressure: 149^0C/ 1.4 barg
Reflux flow: 90~ 105 on tray 1
Gas fired Heater COT: 156
trya 28 Temp: Design 124 and normal operating 122~124^0C
Heater out let pipe:16" and tehn 24" near clumn about 3~4 meter.
NRV:no, only on pump discharge.
Any comments and suggestion are highly appreiciated.
Thanks
Toor

Hi Art and an other seniors,
Could please shed some light on this problem.
Thanks
Toor

Dear Padamaker & Zauberger,
I tried to upload the column PFD but failed to upload the file, the message is coming you are not authorized to upload the file and this is happen with me one more time also.
I complained to administrator and as per him you must login and then upload the file but even though now and previous attempt also I was logged in.
Any how, to understand the Naphtha splitter PFD is not difficult.
Your feed back based on your experience may help me to understand the problem.
Thanks

[Milutin]

Hi Toor,

Your description is bit unclear, when you refer heater, is it naphtha splitter column reboiler heater?
If answer is yes, it seams, when you increase reflux flow you put some light material in bottom product , get higher evaporation in heater coil and COT go down.

As dear colleagues Padmakar S Katre and Zauberberg said scheme will be great help.

Regards,

Milutin