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