anna 2003 transformation of an/can prilling plant into...
TRANSCRIPT
ANNA 2003
Transformation of AN/CAN prilling plant into
granulation plant with Kaltenbach- Tuering FDG
Pan & Dimitri Orphanides
ANNA 2003
•AZOMUES SA operates in Tirgu Mures/ Romania since 1972 among
others one Stamicarbon design, prilled Ammonium Nitrate (AN) 33.5% /
Calcium Ammonium Nitrate (CAN) 27% plant. Design capacity 1400
MTD AN and 1600 MTD CAN. Prilling tower, building and all equipment
are in good condition.
•ORPHANCO from 1999 to middle of 2002 was involved as Technology
Consultant of the privatised Company new Owner.
The new Owner decided in 1999 to improve quality of produced
AN/CAN prills and to replace the prills by granular products : better
sales chances in international markets at higher sales price
A new granulation unit based on proven designs (UHDE pug mill, H-A Fluid
Bed Granulation, Kaltenbach (K-T) Fluid Drum Granulator, and Grande-
Paroisse Fattening Drum – Spherodizer) have been considered
Final decision in favour of revamping of existing unit based on K-T’s
Fluid Drum Granulator Fattening unit
ANNA 2003
Melt 99%
M t/h 34,7%
Recycle R t/h 1000 C
(fines)
Filler F t/h
Dolomite
100%<03mm
Seeds d 50%
p t/h , 34.7%
Fluid
Drum
Granula-
tor
FDG
Slurry
tank
Envelop
E= M+F t/h,
X% Filler
Cooling air
Recycle
Loop
Fig.1 Fattening
Loop
Crushed oversized
product 1% of P
P t/h D50%
Fattening mass rate mr=P/p = D 350% / d 350%,
Air & Dust
Scrubber
Air to atm
Solution to
evaporation
ANNA 2003
Ex X+ px 0.347 = Px 0.27 (CAN), E + p = P
For seeds d50% = 2.2 mm and D50% = 3.0 mm
mass ratio mr is 2.5, X = 22% (means CAN 22%!) R = 1.8p = 0.6P, E= 2p , p= 0.33P For 1400 MTD - AN 33.5%, that means: 510 MTD - 34.7% seeds to FDG, 890 MTD melt plus the required filler. Recycle R about 900 MTD .
For seeds d50% = 2.5 mm and D50% = 3.2 mm mass ratio mr is
2.1, X=20%. Prills and melt quantities are balanced. Filler in
melt slightly higher. R low
For seeds d50% = 2.4 mm and D50% = 3.3 mm mass ratio mr is
2.5, X = 22%. R = about 790 MTD
Optimum conditions for good quality granules
It is important to look for prilling device producing uniform
prills with max. possible d50% !! ANNA 2003
WHY K-Ts FATTENING?
• For final product of D50% 3.0- 3.3 mm,almost half of melt is needed in Granulator. Size of equipment in granulation loop is smaller, resulting in reduction of operating and investment cost
• Fed solids to the FDG are by 35% round prills. Only small fraction recycled fines & product: final product is spherical and its flow characteristics improved.
Fattening plant could be housed in existing building:
• a) civil work cost reduced: FDG to be housed in existing building,
• b) main equipment, reused without relocation,
• c) el. equipment MCC, cables, transformers, lighting etc. reused,
• d) existing control room reused,
• e) engineering & erection work reduced
• f) Completion Time & Investment substantially reduced.
• Granulation control very efficient and easy for AN and CAN 27%
• Low recycle process
• Prilling tower emission substantially reduced
• Flexibility in production for local- (prills) and export- markets (granular)
ANNA 2003
Induced draft
Prilling Tower I
700 MTD AN, or 850 MTD CAN
1000 MTD AN max.
Final
Evaporators
Homogenizer
Hopper for Filler
Hopper for Filler
Spinning
bucket
Stamicarbon
Hot air final evaporator
MP Steam
Remelting
tank
AN solution
95%
AN fines and off-
spec product
Fig.2 Original Prilling Tower System
Homogenizer
AN 99.8%
NH3
MP Steam
To remelting tank
Twin PTs
16.5m ID &
36 m FFH
ANNA 2003
Prilling
Tower
II
Most of AN solution is supplied from the Nitrophosphate NPK plant and contain silica, P2O5 salts (DCP) and higher than usual Calcium nitrate. Sometimes also urea!!! These impurities affect adversely quality of produced prills and cause excessive erosion to the Stamicarbon design spinning bucket, limiting its life to about 2000 h. Original spare bucket with precision perforation holes being very
expensive, replaced by a thin wall self made bucket, limiting further its
lifetime. Produced prills contained excessive amount of fines, shells and clusters,
resulting in a relatively low prill quality with 15% fines separated by screening
and re-melted, increasing production cost.
Quality of prills was not suitable for high final product quality and
following actions have been undertaken to improve the prill quality: • Several additives have been considered to improve the quality
(strength, thermal stability, narrow prill size spread, excellent storage
properties). Aluminium Sulphate was finally selected. • New, adapted to the severe melt composition & to the need for
coarser prill size, Vibrating Prilling device has been selected
ANNA 2003
To melting tank
B 08
Fluid bed cooler 35x 2.2 m
Dedusting
System
Final
product to
storage
Remelting tank
B08
From
prilling
tower
bottom
Screens
Crusher
200m3
Storage
Bin
Liq. NH3
Gas. NH3
Steam coils
6 FBC Blowers, M 03/8 75000 Nm3/h
M11 Blower
164000 Nm3/h
Air conditioning unit
Fig. 3 Original Prill
Conditioning unit
Elevators
2x65 t/h AN fines
Prilling
Tower
I
Induced draft
Prilling Tower
II
idle
Final Evaporators
Homogenizer
Hopper
Additive
Additive
Hopper (SB)
New
Vibrating
granulator
Hot air final
evaporator
MP Steam
Remelting
tank
AN solution
95%
Fig. 4 Revamped Prilling Tower System for the AN/CAN Fattening
Homogenizer
AN 99.%
New line to FDG
Homogenizer
NH3
BL
99.0%
ANNA 2003
AN 99.5%
Aluminum
Sulphate
Fluid bed cooler system
Final product to
storage Remelting tank
B08
From prilling
tower bottom Screens
Crusher
Liq. NH3
Gas. NH3
Steam coils
Air conditioning unit
Fig.5 Revamped unit
KT Fattening Process
Dedusting
System
FDGranulator
AN melt 99%
New
Scrubber
Existing equipment
New equipment
Filler
Homogenizer &
feed pumps
Distributor
To BL
HNO3 H2O
AS (for CAN)
NH3(for AN)
Fig 6a. Side View of Fattening AN/CAN unit – KT Technology
ANNA 2003
Fluid Drum Granulator
Fig 6b. Sectional View of Fattening AN/CAN unit – KT Technology
Fluid Drum Granulator
new
Elevator New
Scrubber new
Fluid Bed Cooler
ANNA 2003
Aluminium Sulphate Dosing Filler Dosing System
ANNA 2003
Homogenizer Top Homogenizer bottom
FDG
Melt
Filler
ANNA 2003
2x50 +1SB Melt Pumps
Suction filter
ANNA 2003
ANNA 2003
Reinforcement of building structure Reinforcement for coating drum ANNA 2003
Scrubber separator
Scrubber blower
Vibrating priller
FDG rolled in to its position ANNA 2003
Conclusion
The plant is producing high quality granular product, meeting all quality
requirements imposed by traders and final clients in many export markets
Control of granulation very efficient and easy, simply by regulating supply of seeds
Problems during commissioning: high reaction temperature & foaming in the
homogenizer, overloading of FBC. Resolved quickly & with minimum cost, by
efficient co-operation between Owner staff & Designer. Remaining problems:
high CN content in CAN (AS addition needed), pH control in final concentrator
due to Al-Sulphate addition, increased abrasion wear when producing CAN.
Investment cost remained within budget limit representing about 45 to 50% of a new granulation unit investment cost
Project completion time was relatively long, mainly due to decisions taken by
Plant Owner and due to local regulations concerning building stability
New vibrating /rotating prilling device contributed substantially to final product very good quality
ANNA 2003
Bulk Flow Cooler could be more suitable for switching production campaigns of Granular - Prilled AN/CAN and for coping with dust load from existing FBC
Last Word
This presentation reflects interpretation of facts, as per
Consultant’s judgment
Plant Owner’s and/or Plant Designer’s opinion possibly differs
at some points
Due to Plant Owner’s product delivery obligations (mainly AN),
Performance Guarantee Tests have to be postponed until the
end of October 2003
Thank You