1. 2011
CO2 STRIPPER
(T-1101)
Problems, Solutions & Suggestions
Report contains stripper history in detail and advanced
technologies introduced for stripper tubing. Style of report is
absolutely different from traditional styles as it gives an
excellent & immediate review of stripper.
SYED ETIZAZ HASSAN
U.E.T LAHORE
8/25/2011
3. [T-1101] [INTERNSHIP 2011]
CONTENTS
x CO2 STRIPPER
x HISTORY OF CO2 STRIPPER(TURN AROUNDS)
x T/A 2009 ,AN EXAMPLE
x CURRENT ISSUES
x SOLUTIONS SUGGESTED
I. TUBES
II. TUBESHEETS
III. DISTRIBUTION TRAY
IV. SWIRLS
GASKETS
V.
x T/A 2012
x PREVENTIVE MEASURES
x MY SUGGESTIONS
WHAT I HAVE LEARNT?????
What I DID FOR ALL OF IT????
THINGS IMPRESSED ME HERE @ ENGRO
ENGRO FERTILIZERS Page 3
4. [T-1101] [INTERNSHIP 2011]
T-1101 in ACES
• A ADVANCE
• C COST
• E ENERGY
• S SAVING
T-1101 Installation
(October-1998)
ENGRO FERTILIZERS Page 4
6. [T-1101] [INTERNSHIP 2011]
CO2 STRIPPER (UREA STRIPPER T-1101)
Stripper in ACES synthesis loop consists of tray part and stripping
part with vertical tubes. The solution from Reactor is fed to tray
part contacting with mixed gas from stripping part. NH3 and CO2
molar ratio is reduced from 4.0 to 3.0 at tray part to achieve
suitable composition for CO2 stripping. Solution from side down
comer of tray part enters on distribution plate. At the
distribution plate, solution is distributed on tube sheet through
holes of distribution plate equally with keeping liquid level
around 100-200mm on the distribution plate.
On the tube sheet, the solution makes liquid level higher than
swirl’s holes by 60-70mm. And the solution enters to swirls’ holes
tangentially to make uniform thin falling film on the internal
surface of tube. CO2 gas introduced at the bottom of tubes as
stripping medium contacts with the solution in the tubes under
the falling film condition. The solution is heated from tube
outside by 20kg/cm2g steam during contacting with CO2 gas.
Carbamate is decomposed and NH3 is removed and separated
from the solution by CO2 gas under the high-pressure condition.
Finally, NH3 content in the solution from the bottom of Stripper
is reduced to 13-14%.
ENGRO FERTILIZERS Page 6
7. [T-1101] [INTERNSHIP 2011]
T-1101 Design by Toyo Engineering
SHELL SIDE
Operating Temperature
417°F(214 °C)
Design Temperature
464°F(240 °C)
Operating Pressure
284 psig
Design Pressure
355 psig
TUBE SIDE
Operating Temperature
356°F/374°F(179/190°C)
Design Temperature
428°F(220 °C)
Operating Pressure
2490 psig
Design Pressure
2613 psig
ENGRO FERTILIZERS Page 7
8. [T-1101] [INTERNSHIP 2011]
METALLURGY
Outer Shell CS Tube DP-12
Internal Lining DP-12 Sieve Tray DP-12
Distribution Tray DP-12 Swirl DP-12, SUS-329, J4L, DP28W
Stay Rod DP-12 Gasket Tombo 9007-SC & Comp Graph
IMPORTANT DATA
Internal diameter top 2600 mm Length top 3060 mm
Internal diameter middle 2500 mm Length after tubes 1000 mm
Tube Length 5963 mm Length bottom 900 mm
No. of Tubes 3100 diameter of Tube 31.8 mm
Thickness of tube 2.9 mm Weep Holes 69
Number of Trays 3 No. of holes per tray 4508
Lining thickness 6mm Corrosion allowance 1.5 mm (tube)
Weight of shell 197000 kg
ENGRO FERTILIZERS Page 8
9. [T-1101] [INTERNSHIP 2011]
HISTORY of T-1101
TURN AROUNDS’ SCHEDULE
1 TURN AROUND 2000(MARCH)
2 TURN AROUND 2001(APRIL)
3 TURN AROUND 2002(OCTOBER 15)
4 TURN AROUND 2004(MARCH-APRIL)
5 TURN AROUND 2005(APRIL)
6 FORCED OUTAGE 2006(OCTOBER)
7 TURN AROUND 2009(MARCH)
ENGRO FERTILIZERS Page 9
10. [T-1101] [INTERNSHIP 2011]
T/A 2000
10 % swirls were swinging & loose
Uneven liquid level on distribution plate
Seal weld leakage testing
ENGRO FERTILIZERS Page 10
11. [T-1101] [INTERNSHIP 2011]
T/A 2001
High bottom temperaturev
100% ECT
Short circulation of liquid from bottom tray
Bottom tray sagging
‘o’ rings damaged
All the swirls were swinging
Stay rods damaged
T/A 2002
Swirls inspection
33% ECT
IPRL arrange adequate inventory of stay rods
IPRL plan repair /replacement of swirls based on
TOYO analysis
Steam side PSV flange gasket replacement
Distribution holes on the distribution plate had been
enlarged
Sample point valves relocation required
ENGRO FERTILIZERS Page 11
12. [T-1101] [INTERNSHIP 2011]
T/A 2004
Lube oil filters Replacement
Swirls holes diameter increased from 2.8 mm to 3.1
mm
60 % ECT
Gaskets and swirl "o" rings damaged
Stay rod damaged
Bare wire for welding (Pak American)
Bottom temp raised to 192 deg C
Ammonia concentration raised to 21.19 %(NH3
rec. system overloaded )and NH3 vapors increased
to 50%
Distribution holes on the distribution plate have
been enlarged
ENGRO FERTILIZERS Page 12
24. [T-1101] [INTERNSHIP 2011]
PREVENTIVE MEASURES
New swirls purchase
Tombo sheets for gaskets and 'o' rings
Stay rods replacement required
Bare wire DP 3T
Prepare for 100 % ECT
Man holes gaskets replacement
Weep holes cleaning and lining judgment
Proper arrangement for seal welder & seal weld cutter
Proper testing of methyl red solution for weep hole testing
UT for shell lining
Distribution plate needed to be replaced
ENGRO FERTILIZERS Page 24
25. [T-1101] [INTERNSHIP 2011]
MY SUGGESTIONS
Tubes replacement (FFC)
2RE69(Cr & Ni ) by Sand vick
Zr layering Omega Bond technology (ATI Wah
Chang) (waiting for quotation)
Seal welding machine & grinder (Ar cooling)
Distributor plate plugging and boring more holes
Thermo vision of stripper lines
ECT report should be sent to TOYO
Experienced persons’ involvement in T/A s
A/C cooling during shutdown
ENGRO FERTILIZERS Page 25
26. [T-1101] [INTERNSHIP 2011]
OTHER THAN MY PROJECT
UREA II
C2E Shutdown
NH3 Line tracing
NH3 Reservoir (D-261)
NH3 Condensers (E-264)
MP 262 A/B
URACA’S Pumps(P 201’S)
ACES Tower visit (Thermo vision)
Prill Tower visit
OVER ALL PLANT
GT startup @ URUT
Packing leak in ST @ enven
Piston repairing @ workshop
Visited skill shop
ENGRO FERTILIZERS Page 26
27. [T-1101] [INTERNSHIP 2011]
Shut down @ urea ii (c2e)
SHUT DOWN @ UREA II (C2E)
ENGRO FERTILIZERS Page 27
30. [T-1101] [INTERNSHIP 2011]
WHAT I HAVE LEARNT?????
Technical data handling
T/A planning
Equipment Order & purchase for T/A
Total maintenance procedure
Collaboration of Operation ,Process, Maintenance ,Inspection ,I& E and Safety section
Non-destructive techniques
Permit protocol
Seniority protocol
Crisis management
Rapid decision making
What I DID FOR ALL OF IT????
Spent most of the time in plant premises
Read all history files and job cards
Visited inspection, planning ,process ,projects
Met the technicians of FM
Coordinated with operators & board men in CCR
Met senior persons worked here before
ENGRO FERTILIZERS Page 30
31. [T-1101] [INTERNSHIP 2011]
THINGS IMPRESSED ME HERE @ ENGRO
Safety and importance of life
Line of protocol
Team work
Qualified staff
Well equipped offices
Ethics & moral values
Well mannered workers
Seniority honor
ENGRO FERTILIZERS Page 31