agritech ltd internship report

INTERNSHIP REPORT

Pak American Fertilizer Limited Iskanderabad Presented By Muhammad Khuram (M08-CE-47) Zahid Mahmood (M08-CE-06) Aqeel Abbas (M08-PG-01) Nouman Asad (E08-CE-40) Arshad Naveed (E08-CE-40) Roman Bin Tariq (E08-PG-19)

Department of Chemical Engineering and Technology

UNIVERSITY OF THE PUNJAB

Downloaded From : http://www.ICETStudentS.com

INTERNSHIP REPORT (Pak American Fertilizer Limited) | University Of The Punjab | 2



ACKNOWLEDGEMENT

First of all, I would like to say Alhamdulillah, for giving me the strength and health to do this internship work until it done We offer our heartily respects to the HOLY PROPHET HAZRAT MUHAMMAD (SAW) who is, forever a torch of guidance and knowledge for humankind as a whole. Not forgotten to our families for providing everything, that is related to this internship work and their advice, which is the most needed for this journey. They also supported us and encouraged us to complete this task so that I will not procrastinate in doing it. Wed like to thanks our respected teachers for their moral support, their guidance in time, useful suggestions and their confidence on us that we can do this task efficiently as we are representing our Institute. Its not very easy for us to find the right words to express my gratefulness to our advisor Mr. ABDUL HASEEB, his enthusiastic interest, continuous encouragement, and kind behavior throughout my internship period. Apart from our respectable advisor, there are many other people who have been very helpful to me right from the beginning. We would warmly acknowledge the entire management of Pak-American Fertilizer Limited who provided us this opportunity to achieve this practical experience under their valuable supervision and helping suggestions to complete this report. Last but not least, my friends internship colleagues who were doing this project with me and sharing our ideas. They were helpful that when we combined and discussed together, we had this task done.



EXECUTIVE SUMMARY This report is based on our four weeks EXPERIENCE at PAK-AMERICAN FERTILIZER LIMITED as an internee from 1st June to 29th June. THE COMPANY IS a highly reputed organization. PAFL is one of the pioneers of the fertilizer industry in Pakistan. It owns and operates urea plant located at Daudkhel, Iskanderabad District Mianwali. The salient features of this report are: Pak-American Fertilizer Limited background, its vision, corporate values and goals. This report focuses its overall marketing strategies, its production and operations, and its Human Resource. The process description of the firm has been done in detail . The flue gas Analysis, water treatment plant Analysis are really a fascinating experience of mine. This report accentuates the details of my learning and observation at PAFL. It also includes the actual techniques that are used in this organization to carry out basic processes. And we were sure that this report will provide you a complete and clear image of organization.



CONTENTS_________________________ HISTORY ................................................................................................6

AMMONIA SECTION............................................................................7

UREA SECTION.....................................................................................27

UTILITIES SECTION............................................................................34



HISTORY The Plant is located at Iskanderabad, District Mianwali. It was the first nitrogenous Plant built in

Pakistan. The project when commissioned in 1957 was designed to produce 40 metric tones per

day of Ammonia to be fully converted into 150 metric tones per day of Ammonium Sulphate.

The unit underwent expansion in 1968 when the capacity was increased to 273 metric tones per

day i.e. 90,000 metric tones per annum of Ammonium Sulphate.

The Ammonium Sulphate Plant was closed in June, 1997 and a new Ammonia /Urea Complex

having capacity of 600 metric tone per day of Ammonia and 1050 metric tone per day of Urea,

started commenced production in November, 1999.

The annual production capacity of the Plant is 346,500 metric tone of urea.

Total completion cost of the Project was Rs.9, 700.060 million, out of which Rs.6, 878.119

million was in foreign currency. The authorized and paid up capital of the Company is Rs.3, 000

million, which is subscribed by NFC.

The raw material used is Natural Gas from SNGPL Network.

Today the plant is running at 1176 tone per day which is the 112% of the designed capacity 1050

tone per day of Urea and 650 tones per day of Ammonia. Both plants have been designed by

TOYO Engineering Japan. Ammonia plant is under license from Kellogg International, USA,

while urea plant is TEC's own. The plants are latest in design and most modern. The company

possesses over 11,481 Kanals of land, comprising 6,432 for Factory, 2,818 for Housing Colony

and 2,230 for experimental farm.



Ammonia Section



GENERAL OVERVIEW Ammonia is produced in a process in which nitrogen and hydrogen react in the presence of

an iron catalyst to form ammonia. The hydrogen is formed by reacting natural gas and

steam at high temperatures and the nitrogen is supplied from the air1.

Other gases (such as water and carbon dioxide) are removed from the gas stream and the

nitrogen and hydrogen passed over an iron catalyst at high temperature and pressure to

form the ammonia. The process is shown schematically in Figure 1.

The ammonia process is the low energy natural gas reforming process. Offered and

licensed by the M.W kellog company. The ammonia plant design is based on producing

6oomtd of anhydrous liquid ammonia.

Under normal operating conditions liquid ammonia is delivered to battery limits at 30 0c.

for uses feed to urea plant in the event that the urea plant is not working the ammonia

product can be delivered to the battery limits -33 0c. for offsite storage.

By product CO2 is delivered to the battery limits at 38 0c and 1.9 kg/cm2.

FEED STOCK SPECIFICATIONS:

Component gas Mole % CH4 82.6 C2H6 8.5 C3H8 3.3 C4+ higher 1.9 CO2 1.3 N2 2.4 TOTAL 100%

Pressure at battery limits: 7.5 kg/cm2 Temp at battery limits: 28 0c Lower heating value (LHV) 9609 K cal/nm3



The process is described in the following sections: Raw synthesis gas preparation: Synthesis gas purification: Purified synthesis gas compression and ammonia synthesis: Ammonia refrigeration system: Process condensate stripper: Steam system: Other utilities:



RAW SYNTHESIS GAS PREPARATION The raw synthesis gas is produced from natural gas is produced from N.G in four major

steps.

Compression. Partial reforming. Final reforming. Conversion of carbon mono oxide and steam in the reformed gas.

N.G is used for feed stock and fuel. The N.G at 7.5 kg/cm2 passes through the feed gas

knock out drum to remove suspended liquids and solids. The N.G is split up in to two

streams feed gas and fuel. The fuel gas portion is combined with recovered gas from

synthesis to provide the ammonia plant net firing requirements. The feed gas portion is

compressed to 46 kg/cm2 in a steam turbine driven two stage centrifugal natural as

compressor. A N.G pressure gas cooler and n N.G knock out drum are provided in order

to provide 2 % hydrogen level in the natural gas stream. A recycle stream of hydrogen rich

synthesis gas from 104 j pump is added to the second stage suction and a start up hydrogen

rich stream from A-103 F pump can be added to the first conditions. A-135-c is also

utilized for spill back from operation which allows all or part of the discharge gas to be

recycled back to the a-102-j first discharge line.

DESULFURIZATION The sulphur compounds contained in small amounts in the feed gas are removed by

catalytic reaction with the hydrogen in the gas over a Como catalyst followed by absorption

with ZnO. The compressed natural gas is heated to 399 0c. in the convection section of the

primary reformer A-101-B. The natural gas and hydrogen combined streams then flow

down through the hydrotreator.

A-101-D hydrogenating the organic sulfur compounds to H2S over a bed of Como catalyst.

The reacted gas then flows through the desulfurizers A-102-DA/B where zone absorbs the



H2S producing an effluent stream containing less then 0.1 ppm by volume of hydrogen

sulfide.

PRIMARY REFORMING The 3880C desulfrized gas is mixed with 44 kg/cm2 and 3900C high pressure steams, a part

of which was used to strip the process condensate before hand. The steam is added in a

ratio of 3.5 moles of steam per mole of organic carbon. The feed gas/steam mixture is then

preheated to 621 0c in the convection of the primary reformer, A-101-B, recovering heat

from the furnace flue gas. After pre heating, the mixture is distributed to the catalyst tubes

suspended in the radiant section of the primary reformer furnace and passes down through

the nickel reforming catalyst. The heat from the endothermic reforming reaction is

supplied by fuel gas burners located b/w the row of the tubes. The pressure at the outlet of

the catalyst tubes is 37.2 kg/cm2 .

The reforming furnace incorporates the use of

internal man folding at the outlet of the catalyst

section for heat conversion of the reformed gas.

The reformed gas continues to pick up the heat

in these risers and collector headers while

exciting the radiant section. This raises the gas

temp aprox to 8330C.

The reforming furnace is designed to attain

maximum thermal efficiency by recovering heat

in the convection section from the flue gases. Flue gases consist of combustion products

from the radiant section of the reformer and the auxiliary boiler.

The convection heat is used for the following services.

Process air. Steam Natural gas feed preheat for desulphurization. Steam super heating.



Reformer fuel preheats. Combustion air preheats for the reformer burners.

The super heat burners in the compression section and the boiler together with the

reformed gas waste heat boiler, A-101-C and the high pressure steam super heater will

maintain the plant in steam balance and generate export stream for the urea and utility

plants.

CH4 + H2O 3H2 + CO CH4 + 2H2O 4H2 + CO2 CO + H2O H2 + CO2

SECONDARY REFORMING The reformed gas flows from the outlet of the primary reformer through the primary

reformer effluent transfer line A-107-D to the secondary reformer A-103-D there it is

mixed with the quantity of heat and air to provide the N2 requirements of ammonia

synthesis reaction the heat librated by combustion of the part of partially reformed gas

supplies the energy needed to complete the reforming action the reformed gas temp leaving

the secondary reformer is about 1013 0C.

CO + H2O CO2 + H2 O2 + 2CH4 2CO + 4H2 O2 + CH4 CO2 + 2H2 2O2 + CH4 2H2O + CO2

The secondary reformer effluents passes directly to the reformed gas waste heat boiler

where SHP steam is generated by by hot gasses passing through the tube side. The partially



cooled gas then passes through the SHP super heater A-102-C and cooled to high temp shift

inlet temp. of 3710C this super heater provides part of steam super heat requirements with

the remaining portion fulfilled by coils in the reformer convection section a process by pass

is provided b/w these two exchangers to various steam balance requirements.

SHIFT CONVERTERS Down stream of A-102-C are high temp, and low temp. Shift converters. A-104-DA and A-

104-DB, in shift conversion step, CO reacts with steam to form equivalent amount of H2

and CO the shift reaction is reversible and exothermic. The reaction rate id favored by

high temp and maximal conversion by low temp. Two stages of shift conversion are

provided with HP boiler feed water heating between them to moderate heating the gas

temp.

CO + H2O CO2 + H2 CO + 3H2 CH4 + H2O CO2 + 4H2 CH4 + 2H2O

The heat from the HTS A-104-DA is recovered by heating high pressure boiler feed water

in the shell sides in series of HTS effluents BFW preheaters, A-103-C1 and A-103-C2.

The low temp. shift effluents provides energy for CO2 removal system with the remaining

use full heat utilized to preheat boilers feed water for the plant steam system in LTS

effluents /BFW pre heaters located down stream of the benfield exchanger in the A-106-C,

Demineralized water is pre heated before it is sent to the dearator A-101-U.

The benfield system utilizes the LTS effluents waste heat as follows:

Steam generation in the CO2 stripper over head condensate reboiler A-113-C,

Benfiled system sol. Reboilng in the CO2 stripper gas reboiler A-105-C.



The process gas is cooled below its dew point in the process gas exchanger and condensate

generated is removed from the gas in the CO2 absorber feed gas separator A-103-F. The

raw condensate is pumped to condensate stripper A-103-E to removed dissolve gasses and

any shift reaction by products so the water is reused and boiler feed make up after

treatment in the offsite polisher.

After condensate removal raw synthesis gas at 75 0C and 32.5 kg/cm2 enters the bottom of

the CO2 absorber A-103-E in the benfield system to begin the purification setup.

SYNTHESIS GAS PURIFICATION In this section synthesis gas is proceed to remove CO2 and CO, yielding a high purity H2

and N2. Bulk removal of carbon dioxide is accomplished by the use of an improved benfield

low heat process which uses the four stage flash of the semi lean sol. to minimize external

heat requirements. Final removal of residual CO2 and CO. is accomplished by catalytically

converting the CO2 to methane and water in the methenator using hydrogen.

The benfield low heat process circulates an aqueous sol. containing a nominal 30%

potassium carbonate

This potassium carbonate chemically combines with CO2 on the process gas but not

significantly with the other constituents. Additives are injected into the solvent to enhance

the CO2 absorption rate, inhibit corrosion and to control foaming.



ABSORPTION OF CO2 In the packed absorber A-101-E, removal of CO2 from the synthesis gas is carried out in

two absorption stages by counter currently

contacting the gas with the benfield sol. raw

synthesis gas enters the lower

Section of the absorber where the major

portion of CO2 in the gas is removed by

contact with partially regenerated semi

lean sol. In the upper section of the absorber

the process gas leaving the lower section is

contacted again but with more thoroughly

regenerated lean sol. resulting in an exit

gas CO2 level of 1000ppmv.

In the upper section of stripper the rich benfield sol. Is the partially stripped of CO2 . A

major portion of the sol. Is then with drawn and fed to A-117-F.

The exiting semi lean sol. is returned to the lower section of the absorber via the semi lean

sol. Circulation pumps. A-107-J, JA.

The reminder of the partially regenerated sol. is further regenerated in the stripper lower

section, where most of the remaining CO2 is removed from the solvent. The resulting

lean sol. is with drawn from the bottom of the stripper cooled to 70 0C. by preheating de

aerator feed water in the lean sol. /BFW preheater, A 107 C and by cooling in the lean

solution cooler A-108 C and then pumped by the lean solution circulation pump A-108-

J,JA to the top of the absorber.



STRIPPER The stripper is operated at conditions of 128 0C and 2.1kg/cm2 at the bottom of the column.

Heat required for stripping, available from low temp. Shift effluent, is obtained by

reboilng, benfield sol. In A-105-C by reboilng reflux condensate in A-113-C, flash cooling

of the semi lean in A-117-F lowers the required heat input to the stripper and enables the

process to operate with out need of sources except during start up. This system maximizes

reboiler heat recovery from the low temp. Shift conversion effluents by taking advantage of

the lower boiling point of the condensate compared to carbonate sol. Blow down from A-

113-C is required to the system by injection in to the lean sol flow through A-105-C.

After separation from the benfield sol. The CO2 product vapor is cooled to 38 0C, by direct

contact cooling with quench or reflux water in a packed bed above the benfield stripping

section of the tower quench water is circulated by the CO2 stripper quench pump. To the

CO2 stripper quench cooler. In this exchanger the quench water is heat is rejected to the

cooling water, water condensed from the CO2 product vapor during cooling is removed

from the cooling circuit to satisfy the water make up requirements. After being cooled the

99% CO2 product passes through the demising pad, exists the tower and is exported for use

in urea.

The absorber over head gas containing approx 1000ppmv CO2, is designed of an entrained

liquid in the CO2 absorber over head knock out drum A-103-F, and preheated to about 326 0C by the methenator effluent in the methenator feed exchanger A-190-C a by pass is

provided around the exchanger to control the inlet temp. A line is provided from A-103-F

exit to the suction of A-102-J to provide H2 for start up and low temp shift reduction.



METHANATOR The metahntorA-106-D contains a bed of nickel catalyst that promotes the reaction of CO2 and CO with H2 to form methane and water. The total carbon oxides leaving the

methanator.

Will be less than 5 ppm by vol. due to highly exothermic nature of the methanation

reactions the synthesis gas temp increase from 316 at the inlet to about 347 0C at the out let.

The heat energy in the methanator efffulent is recovered by the heat exchange against the

feed gas the purified synthesis gas is then cooled to 41 0C on the methanator effluent cooler

A-115-c and delivered to the synthesis gas compressor suction drum A-104-F to separate

condensate water a small flow is taken from

A-104-F exit to the second stage suction of A-102-J to provide the H2 for desulprization.

SYNTHESIS GAS COMPRESSION AND AMMONIA SYNTHESIS The synthesis gas is compressed in a turbine driven centrifugal synthesis gas compressor A-

103-J.the compressor consists of two casings with inter cooling , condensate removal and

molecular sieve purification b/w cases and a integral recycle wheel in the second case, after

compression in the first case to approximately 78.06 kg/cm2 the synthesis gas is cooled to 41

0c in the syn gas compressor interstage cooler A-1116-C,and then cooled to 4.4 0c with

ammonia refrigeration in the syn gas compressor inter stage chiller A-129-C,condenste is

separated from the synthesis make up gas in the syn gas compressor first stage separator,

A-105-F.



MOLECULER SEIVES

following the condensate removal , the synthesis gas passes, through one of the two

molecular sieve driers A-109-DA/DB the driers use molecular sieve absorbents which

remove water and trace amounts of CO2 to less than 1ppm by vol. while one molecular

sieve unit is in use the other is being regenerated on an 8-12 hour cycle or on stand by.

Dried gas exit the on line drier is used to regenerate the molecular sieve vessel not in

service during regeneration of the molecular sieves, the dry synthesis gas is first heated by

super high pressure steam in the molecular sieve regeneration heater, A-173-C, after

passing upward through the molecular sieve bed the refrigeration gas is recycled to the

methenator feed.

The purified synthesis gas leaving the molecular sieve unit is further compressed in the

make up gas section of the high pressure compressor case the fresh synthesis gas is mixed

with recycle gas from the synthesis lope internally with the compressor case before entering

the recycle wheel. Of the compressor, the combined flow to the synthesis lope leaves the

compressor at about 146 kg/cm2.

A syn gas kick back cooler A-175-C, is provided to protect the compressor over a vide

range of operating conditions. A A-103-J, discharge seal oil separator, A-111-L, is provide

at he compressor discharge to trap only oil from the compressor during an upset.



AMMONIA REACTOR Before going directly to the ammonia reactor synthesis gas leaving A-111-L, is preheated in

the ammonia converter feed exchanger , A-121-C, to 253 0c and sent directly to the

converter provisions has been made for by pass of the exchanger to control the temp. of the

converter feed.

N2 + 3H2 2NH3 The horizontal ammonia synthesis converter consists of a pressure shell, a removable

catalyst basket, and a ammonia converter interchangers. The converter contains 31.6m3 of

synthesis catalyst divided into three thermodynamics beds and four physical beds, each

supported on profile wire screens. The catalyst beds are arranged so that the first bed is the

smallest to limit the temperature rise. The feed gas to the converter is split into two

streams. The first feed split stream passes through an annular space between the shell and

converter basket. This helps to cool the shell and keeps the converter basket at a uniform

temperature. This feed gas stream receives some preheat prior to interchanger tube side

where it is preheated to the desired first bed temperature. The second feed split stream is

heated in the second interchanger tube side before mixing with the first preheated split

feed stream. The preheated total converter feed stream passes down through the first

catalyst bed where over 50% of the total ammonia conversion occurs. The first bed effluent

is cooled by passing through first interchanger shell side and flows to the second bed.

The cooled first bed effluent passes down through the second catalyst bed where more

ammonia conversion and temperature rise take place. The effluent from the second bed is

cooled passing through the shell side of the second interchanger before flowing down over

the third beds. The third catalyst bed is divided into two physical beds in series flow

configuration. This is to ensure uniform flow over the catalyst. Further reaction in the

third catalyst beds raises the converter outlet temperature to about 454 0C and the

ammonia concentration to 15.8 mol %.



The design feature of an intercooler horizontal ammonia converter has the advantage of

producing a relatively high ammonia concentration per pass and making the heat available

in the converter effluent at a sufficiently high temperature for high pressure steam

generation. The horizontal arrangement of the converter produces a lower pressure drop

through the catalyst beds then a vertical, axial-flow type and enables removal of the basket

and interchanger

by using a diameter that is within the fabricating limitations of full closure.

The heat of reaction from the ammonia synthesis is recovered from gas leaving the

converter by cooling it to 278 0C in the ammonia converter effluent BFW preheaters.

The cooled converter effluent is further condensed in the ammonia converter effluent

recycle exchanger. This specially designed chilled further provides for cooling of the

converter effluent through interchange of the heat with ammonia vapors returning from

the ammonia product separator and boiling ammonia liquid at four different temperature

levels ( 20.6 0C, 0 0C, -17.9 0C, -33.3 0C).

This unitized chiller consists of multiple co centric tubes which run through the boiling

ammonia compartments. Synthesis gas recycle vapors pass counter currently through the

center tube and the converter effluent flows through the annular tube. Thus, the converter

effluent is being cooled from the outside by ammonia refrigeration and from the inside by

vapor from the ammonia separator. The converter effluent is condensed at -17.8 0C in the



unitized chiller and the liquid product disengaged immediately downstream in the

ammonia product separator.

Recycle vapor from the ammonia separator, containing near 2.79 vol% ammonia, is

reheated in the unitized chiller as described above. After leaving the exchanger, a small

portion of the gas is split off to the ammonia absorber, to prevent inert gas accumulation in

the loop and recover the remaining

ammonia in the purge gas. The remainder of the recycle vapor is directed to the synthesis

gas compressor, mixed with fresh synthesis loop feed, and compressed for reuse as feed to

the converter.

Liquid from the ammonia separator is flashed into the ammonia letdown drum. The

flashed vapor, primarily inert, is mixed with the refrigeration system purge gas and sent to

the ammonia absorber. The liquid ammonia product is then split into several streams

leading to the refrigeration system and to the purge gas cooler section of the refrigerant

receiver.

AMMONIA REFRIGERATION SYSTEM A four stage ammonia refrigeration system provides refrigeration for ammonia

condensation in the synthesis loop, recovery of ammonia from vented gas, and synthesis gas

compressor make-up gas chilling. The four refrigeration levels operate at approximately

20.6 0C, 0 0C, -17.9 0Cand -33.3 0C.

The refrigeration system consists of a two-case centrifugal compressor with two

intercoolers, a refrigerant condenser, a refrigerant receiver, evaporator and a four stage

flash drum which forms an integral part of the unitized exchanger. Provision is made for

contact chilling and venting of any inert gases dissolved in the warm liquid ammonia

product.

Additional provision is made to recover a small amount of ammonia vented from

atmospheric storage to the first stage suction of the refrigeration compressor.

Ammonia vapor from the second case of the ammonia refrigerant compressor is cooled,

condensed at 38.2 0C in the refrigerant condenser and then sent to the refrigerant receiver.



Inert and uncondensed ammonia vapor from the refrigerant receiver and the refrigerant

condenser enter the contact chiller section on the top of the receiver where it is washed with

cold ammonia from the ammonia letdown drum condensing the ammonia to drain back to

the vessel. The inert gases containing ammonia vapor from---along with the flash gases

from ---- are sent to the ammonia absorber.

A major portion of the liquid ammonia from the refrigerant receiver after mixing with a

small amount of the cold ammonia from the letdown drum leaves as warm ammonia

product from the plant. It is pumped by the hot ammonia product pump to the urea plant.

The remaining liquid is flashed into the fourth stage refrigerant flash drum at 20.6 0C and

8.9 kg/cm2a. Liquid in the fourth stage drum provides refrigeration to the fourth stage

chiller section of the unitized exchanger.

Liquid from the fourth stage drum is flashed by letdown into the third stage refrigerant

flash drum at 00C and 4.4 kg/cm2. a portion of the liquid from the fourth stage refrigerant

flash drum is routed to the synthesis gas compressor interstage chiller with the vapors

delivered to the third stage flash drum. Liquid in the third stage drum provides

refrigeration directly to the third stage chiller section of the unitized exchanger.

Liquid from the third stage drum is flashed into the second stage refrigerant flash drum at

-17.9 0C and 2.1 kg/cm2a. liquid in the second stage drum provides refrigeration directly to

the second stage chiller section of the unitized exchanger. The net liquid from the second

stage drum is flashed into the first stage refrigerant flash drum at -33.3 0C and 1.0kg/cm2a.

Liquid in the first stage drum provides refrigeration directly to the first stage chiller

section of the unitized exchanger and can also be sent to the atmospheric storage tank via

the cold ammonia transfer pump.

The vapor generated in the four refrigeration drums are fed to the appropriate stage of the

two case, steam turbine driven centrifugal ammonia refrigerant compressor. The heat of

the compression is rejected to the refrigerant compressor 2nd stage intercooler and to the

refrigerant compressor 3rd stage intercooler. The vapors are compressed, condensed, and

returned to the refrigerant receiver, thus completing the refrigerant cycle.



PROCESS CONDENSATE STRIPPER Process condensate from the carbon dioxide absorber feed gas separator is recovered and

reused in the ammonia plant after treatment.

Process condensate can contain up to 1000 ppm (by weight) ammonia, 3000 ppm (by

weight) carbon dioxide, and 1000 ppm (by weight) methanol and higher alcohols. Before its

reuse, the condensate is stripped by steam in the process condensate stripper to reduce the

ammonia content to about 10 ppm (by weight) , carbon dioxide content to less than 10 ppm

(by weight) , and the combined methanol and higher alcohol content to approximately 25

ppm (by weight) . The stripped condensate may also contain up to 2.5 ppm (by weight) of

metals.

The treatment of the process condensate is carried out by steam stripping in a packed

column using a portion of the high pressure process steam. The process condensate is

preheated by the stripper effluent in the condensate stripper solution exchanger, and then

distributed to the top of stripper packing. The process condensate is stripped by the rising

counter current flow of steam. The stripper overhead is mixed with the remaining process

steam and combined with the desulphurized process natural gas and enters the primary

reformer mixed feed coil. The stripped condensate, after partial cooling in the condensate

stripper solution exchanger, is further cooled with cooling water in the stripped condensate

effluent cooler at 41 0C before being sent to water treatment plant.

AMMONIA RECOVERY SYSTEM The high pressure purge gas from the synthesis loop along with the flashed gases from A-

109-f and A-107-F are sent to the ammonia absorber via the purge gas ejector. In the

packed tower at 60.7kg/cm2a/ ammonia is absorbed by the water wash. The absorber

overhead gas is used as fuel in the primary reformer.

The solution leaving the absorber with the ammonia concentration of about is heated

about in the ammonia solution exchanger,against hot water from the ammonia rectifier,



bottoms. The heated aqueous solution enters the ammonia stripping column below the

reflux section of packing. Liquid ammonia reflux to the top of the stripper.

Column is provided from the refrigeration system via a side stream at the discharge of the

hot ammonia product pumps. The ammonia vapor from the top of the column is fed to the

refrigerant condenser, -- where it is condensed.

Stripping heat is provided by the ammonia rectifier reboiler, which uses high pressure

steam. The ammonia solution exchanger cools the rectifier bottoms which contain (weight)

to and the ammonia solution cooler, cools the stripper water to -- . a small amount of

condensate from is added to the rectifier as needed to make up for water losses in the

absorber overhead. A scrub water pump is used to pump the cooled water to the top of the

absorber.

STEAM SYSTEM There are three principle steam system in the ammonia plant. In order to effectively

recover heat efficiently from the process, a super high pressure superheated steam

system is used to drive the major movers in the plant. This super high pressure steam is

generated in the auxiliary boiler and in the reformed gas waste heat boiler and is used to

drive the synthesis gas compressor, -- and refrigerant compressor, -- turbines. Boiler feed

water for this generation system is pumped by the h. p. blew pump through the boiler feed

water heaters, --and to the steam drum. the super high pressure steam is also used in the

mathanator start up heater, and the molecular sieve regeneration heater and is let down as

well to the high pressure header when any of the above turbines is down.

The high pressure header at 44.0kg/cm2a, 390 0C is the principle distribution system in the

plant. It is supplied by the extraction steam from A-103-JT AND A-105-JT and by letdown

when the plant is not in full operation. The motive steam for the air compressor , natural

gas compressor, H.P. BFW pumps, condensate pump for A-101-JC, forced draft and

induced draft fan, semi lean solution circulation pump, and lube oil and seal oil pump

turbines is supplied from this system along with the process steam for the condensate



stripper and for the primary reformer, and the reformer air coil. High pressure steam is

also exported to the urea plant.

The low pressure header (4.5kg/cm2a, 282 0C) is the distribution system for the low energy

level users in the plant. It is supplied by the exhaust steam from the condensate pump,

forced draft and induced fans, the seal oil and lube oil pumps turbines, the seal leak-off

steam from A-103-JT and A-105JT, and also the exhaust steam from the steam blow down

drum. It supplies part of the

motive steam for the air compressor turbine and surface condenser ejectors, and the

heating steam for the dearator and various small process users.

The surface condenser is used to provide low level exhaust conditions (99 mmHga, 50 0C)

for the process major prime movers. The capability of this unit to condense steam at very

low energy conditions bears directly on the efficiency and economic success of the plant.

This condenser receives vapor from the exhaust of the synthesis gas compressor, air

compressor, natural gas compressor, and the H.P. BFW turbines and also from the urea

plant. The collected condensate is pumped out of the condenser by the condensate pump(s)

send to the secondary reformer water jackets and to water treating for reuse in the plant.



Urea Section



GENERAL OVERVIEW Urea [CO (NH2)2], also known as carbamide or carbonyl diamide, is marketed as a

solution or in solid form. Most urea solution produced is used in fertilizer mixtures,

with a small amount going to animal feed supplements. Most solids are produced as

prills or granules, for use as fertilizer or protein supplement in animal feed, and in

plastics manufacturing. Five U. S. plants produce solid urea in crystalline form.

About 7.3 million mega grams (Mg) (8 million tons) of urea were produced in the U. S

in 1991. About 85 percent was used in fertilizers (both solid and solution forms), 3

percent in animal feed supplements, and the remaining 12 percent in plastics and

other uses.

UREA MANUFACTURING PROCESS The process for manufacturing urea involves a combination of up to 6 major unit operations.

Urea plant is generally divided into following sections.

1- Compressor

2- Synthesis Section & high pressure recovery.

3- Purification & Recovery Section.

4- Concentration Section.

5- Prilling Section.

6- Waste Water Treatment Section.



PROCESS DESCRIPTION

SYNTHESIS SECTION & HIGH PRESSURE RECOVERY In the solution synthesis operation, ammonia (NH3) and carbon dioxide (CO2) are

reacted to form ammonium carbamate (NH2CO2NH4).

Typical operating conditions include temperatures from 180 to200C (356 to 392F),

pressures from 140 to 250 atmospheres (14,185 to 25,331 kilopascals) NH3:CO2 molar

ratios from 3:1 to 4:1, and a retention time of 20 to 30 minutes. The carbamate is then

dehydrated to yield 70 to 77 percent aqueous urea solution. These reactions are as

follows:

ACES21 process synthesis section consists of a

reactor, a stripper and a carbamate condenser.

Liquid ammonia is fed to the reactor via the HP

Carbamate Ejector which provides the driving

force for circulation in the synthesis loop

instead of the gravity system of the original

ACES. The reactor is operated at an N/C ratio of

3.7, 182 C and 152 bar. The CO2 conversion to

urea is as high as 63% at the exit of the reactor.

Urea synthesis solution leaving the reactor is

fed to the stripper where unconverted

carbamate is thermally decomposed and excess

ammonia and CO2 are efficiently separated by

CO2 stripping. The stripped off gas from the stripper is fed to the Vertical



Submerged Carbamate Condenser (VSCC), operated at an N/C ratio of 3.0,180C and

152 bar.Ammonia and CO2 gas condense to form ammonium carbamate and

subsequently urea is formed by dehydration of the carbamate in the shell side.

Reaction heat of carbamate formation is recovered to generate 5 bar steam in the tube

side. A packed bed is provided at the top of the VSCC to absorb uncondensed

ammonia and CO2 gas into a recycle carbamate solution from the MP absorption

stage. Inert gas from the top of the packed bed is sent to the MP absorption stage.

PURIFICATION & RECOVERY SECTION The major impurities in the mixture at this stage are water from the urea production

reaction and unconsumed reactants (ammonia, carbon dioxide and ammonium

carbamate). The unconsumed reactants are removed in three stages3. Firstly, the

pressure is reduced from 240 to 17 barg and the solution is heated, which causes the

ammonium carbamate to decompose to ammonia and carbon dioxide:

At the same time, some of the ammonia and carbon dioxide flash off. The pressure is

then reduced to 2.0 barg and finally to -0.35 barg, with more ammonia and carbon

dioxide being lost at each stage. By the time the mixture is at -0.35 barg a solution of

urea dissolved in water and free of other impurities remains. At each stage the

unconsumed reactants are absorbed into a water solution which is recycled to the

secondary reactor. The excess ammonia is purified and used as feedstock to the

primary reactor.

CONCENTRATION SECTION

75% of the urea solution is heated under vacuum, which evaporates off some of the

water, increasing the urea concentration from 68% w/w to 80% w/w. At this stage

some urea crystals also form. The solution is then heated from 80 to 110oC to

redissolve these crystals prior to evaporation. In the evaporation stage molten urea



(99% w/w) is produced at 140oC.The remaining 25% of the 68% w/w urea solution is

processed under vacuum at 135oC in a two series evaporator-separator arrangement.

PRILLING SECTION. There are 2 types of prill towers: fluidized bed and non fluidized bed. The major

difference is that a separate solid cooling operation may be required to produce

agricultural grade prills in a non fluidized bed prill tower.

The solids screening operation removes off size product from solid urea. The off size

material may be returned to the process in the solid phase or be redissolved in water

and returned to the solution concentration process.

Urea is sold for fertilizer as 2 - 4 mm diameter granules. These granules are formed

by spraying molten urea onto seed granules which are supported on a bed of air. This

occurs in a granulator which receives the seed granules at one end and discharges

enlarged granules at the other as molten urea is sprayed through nozzles. Dry, cool

granules are classified using screens.

Oversized granules are crushed and combined with undersized ones for use as seed.

All dust and air from the granulator is removed by a fan into a dust scrubber, which

removes the urea with a water solution then discharges the air to the atmosphere. The

final product is cooled in air, weighed and conveyed to bulk storage ready for sale.



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Utility section



GENERAL OVERVIEW Utilities include the following sections

Water intake facility Water treatment plant Cooling tower IGG (Inert gas generation) G.T(Gas Turbine), HRSG (Heat recovery and steam generation) Package Boiler Mitsui Boiler

WATER INTAKE FACILITY For the supply of raw water, PAFL has its own water pumping station near Indus River

(Banian Tree site/area.). The Raw water coming from Banian Tree area is used for the

following purposes:

Make up water for Cooling Tower (old +new).Normal raw water use=3000m3

Potable water at Plants.

Potable water at PAFL Housing colony.

Water Treatment plant to produce DM water.

As cooling water during emergencies.

As fire water, 1100m3.

Water intake facility comprises on the following:

TUBE WELLS 06 tube wells are in operative condition, designed capacity of these tube wells is 3.0 cusec

but due to continuous operation, capacity of old pumps (installed in 1997and before)has

dropped to 2.0 ~ 2.5 Cusec.

1. No of Tube Wells in operative condition, installed before 1997 .01

2. No of Tube Wells in operative condition, installed in 1997 .03



3. No of Tube Wells in operative condition, installed in 2004 .02

(For these two tube wells, new bores were drilled; one new pump and one old pump were

installed)

PIPE LINE 1. 24 and 3948 meters length Pipe Line from Banian Tree to PAFL plants.

12 ~ 08 and 1500 meters length Pipe Line from PAFL plants to Housing Colony.

RAW WATER ANALYSIS

pH 7.5-7.6

M. Alkalinity 120-130 ppm CaCO3

Calcium 112-125 ppm CaCO3

Magnesium 40-50

Total hardness 1 60-170

Chlori de 10-17 ppm

Sulphate 40-50

Silica 12-16

WATER TREATMENT PLANT: For the production of de-mineralized water, required for steam generation PAFL has a

water treatment plant of El-Car Company of Italy having 85-tons/hr capacity. This plant

comprises on three sand filters and two Ion Exchange Lines, each line comprising on

Cationic exchangers, de-gasifier, and Anionic exchangers, mixed bed and Auxiliaries for

the regeneration of these Ion exchangers. Operating hours of each line/train are:

Cation exchanger/Anion Exchanger = 1020 m3

Mixed Bed = 168 hrs

Following resins are being used at Water treatment Plant

a) Strong Cation resin (for Mixed bed exchanger) Amber jet 1200 Na b) Strong Anion resin (for Mixed bed exchanger) Amber jet 4200 Cl



c) Weak Acid Cation resin (for Cationic exchanger) D 113/ Dilute C 433 d) Strong Acid Cation resin (for Cationic exchanger) Amber jet 1200 Na e) Strong base Anion resin (for Anionic exchanger) Amber jet 4200 Na

For the regeneration of Cationic resins 98% H2SO4 is used and for the regeneration of

Anionic resins 50% NaOH is used.

COOLING TOWER Purpose: Cooling water is used at a plant for condensing steam, for cooling product feed gases, and

also for equipment cooling. It is considered, to beWATER and the WET BULB

temperature of the air surrounding it.

Brief Description: PAFL cooling tower is an

induced draft type-cooling

tower with Counter Flow

design. The air enter the

tower through the louvers at the

tower base, pulled upward and

comes in contact with falling

droplets of water.

In the counter flow towers, the

drift eliminators are located at the top. The eliminators are placed just ahead the fans to

prevent windage losses.

These types of towers are specially designed to minimize windage and drift losses which are

controlled at 0.005 % and 0.3 % of the water circulation rate.

The main component of a cooling water cell is.

1. A frame work i.c. outer structure of a cooling tower cell. 2. A system of fluid distribution and dispersion above the fill (fill: packing).



3. A film pack fill, which acts as a heat exchanger between the liquid and air. 4. A catchments pond or bay which provides the recooled water to various consumers. 5. A fan which induces the draught. 6. A drift eliminator is to catch the water droplets practically going out with air.

Design Data:

Item No. C-EF-3301 A-F

Service Cooling Tower

Quantity One (1) with six cells.

Type Mechanical draft - Counter flow

Design and Operating Conditions: Circulating water flow 15000 M3 / hr.

Hot (Inlet) water temperature 43 oC

Cold (Outlet) water temperature 33 oC

Wet bulb temperature 30 oC

Tower pump head 9.76 M

Total fan B.H.P 777 KW

Drift losses 0.01 % (of circulated capacity)

Evaporation losses 1.66 % (of circulating cap)

Design wind load 44.4 m / Sec.

Design seismic load 0.12 % G.

Tower site Ground level (Tower will be constructed above

ground level).

Elevation above sea level 228.5 m

Tower exposure Open

Structural Details: Number of cells Six (6)

Fan per cell One (1)



Total number of cell Six (6)

Nominal cell dimension 12.85 x 13.60 M

Over all tower dimension 78.76 x 13.96 M

Height of fan deck 12. 18 M

Fan stack height 3.2 M

Over all tower height 15.38 M

Inside basin dimension 78.16 x 15.60 M

Hot water inlet pipe points Six (6)

Nominal dia. 32 (24) Height of inlet pipe 9.26 M

Access to top of water Stairway and cage ladder

Material Of Construction: Frame work Reinforced concrete (RC.)

Casing RC

Filling Poly propylene (PP) Grid

Supports 304 SS

Drift eliminators PVC

Spacer PP

Fan stacks FRP

Louvers RC

Partitions RC

Water distribution Channel

Material RC / HD4 Steel Pipe

Splashers of spray Nozzles Poly propylene (PP)

Bolts, Nuts, washer 304 SS

Mechanical equipment support HDG steel (Supplied by Hamon)

Anchor Bolts material HDG Steel

Cold water basin RC



First Time Water Filling / Cleaning: First clean the basin toughly and fill it with raw water. The feed valves to the cells are closed and only open flushing valve. Pump the water round the circuit for some time, in order to clean the circuit. Under

no circumstance the water from the first start up be fed to the cells since this water

being dirty and is likely to block the nozzles.

Once the circuit has been properly flushed, the pumps are to be stopped, the basin emptied and cleaned out.

Fill the basin / bay again with water and start operation. Start-up the pump, to avoid water hammering open the cell feed valves slowly. Check the equilibrium of water distribution between the cells. Check the water level of each cell under normal condition. Check the flow to ensure

that the design flow is not exceeded. The Bay, Nozzles, Fill all are designed to

tolerate only 15-20 % of increased flows then design condition.

OPERATION FIRST START-UP

Checks Before The First Start Up: 1. First check fan shaft alignment maximum tolerance is 0.05 mm. 2. Check the fan pitch. 3. Check oil level in the gear box. 4. Manual check of rotation of motor / fan unit. 5. Ensure that no stray material like boards, ladders and tools are present their. 6. Check the rotational direction of motor, if not correct reverse the terminal

connection.



Start Up Of Fans: The first start up of fan is done with no water flow.

Check that power is available. Check the power requirement of fan and adjust its Pitch in accordance to power

demand / ambient temperature.

Point: It is to be noted that more power is required when fan is running without load (with no

water)

Check the bearing vibration / noise. This process of fan operation should continue far one hour. Stop after one (1) hr of running and check all bearings / oil temperature. If no overheating is found, then run for another 4 hour and check temperatures of

oil and bearings again.

No over heating of bearing is said to occur when temperature less than 40 oC.

RESTARTING AFTER A STOPPAGE

Preliminary Checks: Check gear box oil level. Check rotation of motor. Check water level in Bay. Check that vibration switch is on. Check that no other material is present in the Bay, which can cause problem during

operation.



IGG (INERT GAS GENERATION) Purpose: The linde-PSA (Pressure swing adsorption) plant works according to the principle of

Adsorptive separation of air. The use of the adsorption technique in the recovery of gases

is based on the ability of porous adsorption material. The loading capacity of gases depends

on pressure and temperature and these two parameters are used to separate gases.

About 98 % is removed from air (nitrogen) and remaining 2% oxygen is removed by

reacting with hydrogen in pressure of noble catalyst.

DESCRIPTION OF PROCESS Compression Ambient air will be compressed to a working pressure of 10 kg/cm2 by an oil free screw

compressor. The moisture in air will be drained automatically in the shape of condensate.

Adsorption Water and CO2 will be adsorbed preferentially in the inlet zone after which O2 is

adsorbed. The product N2 flows from the absorber out let to the N2 buffer vessel and then

to the deoxo system.

Adsorption After the adsorption of water, CO2 and O2, the desorption of these gasses will be done to

the atmosphere.

Pressurization After completion of the desorption process, the adsorption phase will start by pressure

equalization between the two adsorbers. Further pressure will be developed with process

air by the air compressor.

The two absorber having the following cycles.

Adsorption (N2 production) Desorption (Depressurization) Again pressures build up.



Deoxydation N2 gas from PSA unit is fed to deoxy system where the rest of oxygen is removed by

recombination with hydrogen. The gas is cooled by air and water; the condensed water will

be drained.

Drying The remaining water is removed by means of an adsorption drier. The drier consist of two

beds. One bed is in the adsorption mode and the other in the regeneration mode.

Regeneration will be done by heating-up and then purging.

Safety 1. Smoking and all naked flames are prohibited. 2. Take special measures to avoid electrostatic charges. Do not wear shoes studded

with iron nails.

3. Parts exposed to O2 must be free from inflammable materials. 4. The clothing of personnel must be free from any oil and grease. 5. The greased parts must be cleaned only with hydrocarbon chlorides or hydro

carbon fluorine chlorides.

6. The storage of combustible material in plant area is prohibited. 7. Prior to personnel entering to Nitrogen processing vessels and piping the

equipment must be purged with dry air. The laboratory analysis must be done

before vessel entry.

8. It is prohibited to work in the area where concentration of N2 is more than the recommended.

DESIGN DATA

Air Consumption Air Consumption C-1161

Air consumption 1800 m3 /hr (process Air)

Design air inlet of adsorber 1340 Nm3 / hr.

Barometric Pressure (Inlet) 0.982 bar (a)

Ambient air temperature (Inlet) + 48 oC



Relative Humidity 85 %

Outlet temperature of air 63 oC

Pressure of Air 0.982 bar (a)

Plant Capacity

1. Gaseous N2 product. 400 NM3 /hr. 2. O2 content


Design data

Volume 2.1 m3

Max. working pressure 12.0 bar ( a )

Maximum working temperature 80 oC

Diameter 1000 mm

Overall height 3930 mm. Silencer

Manufacturer LOHENNER

Design Data

Volume flow Max. 9200 NM3 /hr.

Pressure drop


Design Data

Volume flow max. 450 Nm3 /hr.

Max. permissible working press. 11.50 bar ( a )

Max. permissible working temp. 300 oC

Length 2250 mm

Width 1200 mm

Overall height 2600 mm H2 ( Hydrogen): Consumption 28 Nm3 /hr.

Pressure 9 - 12.5 bar ( a )

Temperature 45 oC

Analysis

N2 24.7 % by V

Ar 0.30 by V

CH4 0.80 by V

H2 74.2 % by V

Adsorption drier : Manufacturer ULTRAFILITER

Warm regenerated two-bed adsorber system as package unit.

Design Data

Volume flow max. 446 Nm3 /hr.

Max. permissible working press. 11.5 bar ( a )

Max. permissible working temp. 120 oC.

Length 1020 mm

Width 1150 mm

Overall height 2765 mm



PLANT OPERATION Start up: The plant operation is very simple as the unit is fully automatic as soon as we push the

button the product of N2 will be delivered with-in a few minutes.

Before starting the plant following points must be checked in detail.

1. Check that power is available. 2. Check that cooling water is available. 3. Check that hydrogen (H2 ) is available. 4. Check that instrument air is available. 5. Start air compressor unloaded by pressing button HS-1101. Then switch the

compressor to load.

6. Start PSA (pressure swing Adsorbed) by pressing button HS-2701.After some time (few seconds) the PSA-valves will work according to the start-up cycle. As

long as purity of the gases are bad, N2 will be vent through the silencer of the N2

drier via S-2780, PCV-2794 is closed.

7. Start N2 drier by pressing button HS-2727. 8. If N2 purity at QIC-2757 is higher than 98 %, start deoxo by pressing HS-

2741. Also start H2 - supply via H2 control valve -2762 simultaneously.

9. It O2 content at QIC-2792 is lower than 10VPPM, then open the product valve PCV-2794 and close S-2780.

SHUT-DOWN MANUAL SHUT-DOWN

1. Stop the deoxo by pressing HS-2741. The product valve PCV-2794 will be closed and by-pass valve S-2780 will be opened.

1. Butter fly valve 2760 will close. 2. The pressure in the deoxo and drier will be released to the atmosphere.



3. Stop the air compressor by pressing HS-1101. 4. Stop the PSA by pressing HS-2701. 5. Stop the drier by pressing HS-2727.

EMERGENCY SHUT-DOWN

If there is any danger for plant equipment or operating staff, shut-down the plant by

emergency push buttons They will become stand still within a few seconds due to its

PLC ( programmable logic controller )

TROUBLE SHOOTING

If the plant is shut OFF as per Common alarm take the following actions for resetting.

- First reset horn by push button HS-9302.

- After problem has been solved reset alarm by push button HS-9301.

TROUBLE SHOOTING OF ADSORBER SYSTEM

If the product purity is lower than designed then.

1. Check pressure rising and final pressure of each adsorber. If there is a difference in the pressure of two adsorber, check the sealing of all piping

connections and flanges for any leakage.

2. Check the correct functions of all butterfly valves. 3. If the rise in pressure and final pressure of each adsorber is identical then. o Check quantity of delivered compressed air. o Check the adjustment of product flow valve FCV-2794. Increase in product flow

means less product purity and vice versa.

o Check the drain of the air compressor. o An increase of water content in process air means a decreasing of product purity

/ quantity.

o Check the inlet temperature of compressed air into the adsorber unit High inlet temperature means low product purity.



Trouble shooting of Deoxo system.

If product purity is lower than designed then.

1. Check correct hydrogen supply.

2. Check temperature rise of the gas in the deoxo-reactor (TISA-2765). If temperature

rise is two low, insufficient reaction takes place which means decreasing product purity. If

the temperature is too high, the adsorber station is delivering gas with too much O2.

IMPORTANT REASONS FOR PERFORMANCE LOSSES

- Leakage of valves, flanges or other connections.

- Wrong switching lines of valves.

- Moisture, dust and solid particle in blow off silencer

- Fouling of adsorber molecular sieves by oil/moisture etc.

- Changing of ambient conditions (day and night drifting)

- Adsorber not completely filled up with ZMS (ZEOLITHIC MOLECULAR SIEVE)

Boiler # 1 HR&SG: Boiler No. 1 is manufactured by bibcock and Wilcox Company of U.S.A and was installed

in 1954. Initially it was designed for coal firing, but in 1972 its firing method was modified

and changed from coal burning to Natural gas burning. Its steam generation capacity is

155000 Ibs/hr and is used for supplying steam for power generation and to Phase-II for

plant operation.

Manufacturer = Babcock & Wilcox Boilers Type = Water tube Capacity = 155000 Ib/hr Steam pressure = 775 Psi (g) Heating surface = 13948 sq. ft. Fuel = Natural gas (modified) coal (design) No. of Burner = 04



Boiler water holding capacity = 96,400 Ibs (at normal level) Furnace draft = Balance draft Heat recovery system = Tubular type air pre-heater Temperature control system = Attemprator, surface contact type.

Boiler # 3 or Mitsui Boiler Manufacturer Mitsui Engineering Corporation, Japan Evaporation Capacity at peak 90,000 Kg/hr

at MCR 85, 000 Kg/hr

Design pressures 60 Kg/cm2 G. Steam pressure at super heater outlet 50 Kg/cm2 G. Steam temperature at super heater outlet 450 + 5 oC Feed water temperature drum inlet 165 oC Draft system forced draft Firing system oil & gas Fuel natural gas

Furnace oil

Heat recovery system gas air heater

The Mitsui Boiler is fitted with combination firing steam using oil and gas as fuel. Burners

firing are automatic and equipped with safety tripping devices.

The unit is equipped with wind box housing adjustable blade type air regulator for

producing the necessary turbulence, air movement, provided with manual control device,

inspection and ignition doors, stainless steel damper impeller, explosion door etc.

For fuel oil firing, complete line starting from Furnace oil receiving station to all burners.

Each burners is provided with manual shut off and electro-preumatic shut off valve

connected to flame protection devices. Steam consumption for Furnace oil atomization is

not more than 1.1% of Boiler minimum production.



Turn down ration of the Boiler is not less than 4 to 1

Package Boiler

Manufacturer HMC, Pakistan Evaporation Capacity 30000 Kg/hr Design pressures 45 Kg/cm2 G. Steam temperature at super heater outlet 395 + 5 oC Air temperature at FDF inlet 25 oC Draft system forced draft Fuel natural gas Heat recovery system Economizer

The Package Boiler is fitted with combination firing steam using oil and gas as fuel.

Burners firing are automatic and equipped with safety tripping devices. The unit is

equipped with wind box housing adjustable blade type air regulator for producing the

necessary turbulence, air movement, provided with manual control device, inspection and

ignition doors, stainless steel damper impeller, explosion door etc.

For fuel oil firing, complete line starting from Furnace oil receiving station to all burners.

Each burners is provided with manual shut off and electro-pneumatic shut off valve

connected to flame protection devices. Steam consumption for Furnace oil atomization is

not more than 1.1% of Boiler minimum production.

Instrument air/ Plant air section For the supply of plant air and Instrument air, a air compressor IGB 3601 A having

capacity of 3520 Nm3/hr is provided along with the provision of air supply from Ammonia

plant air compressor 101 J.

To meet power failure emergency air compressor IGB 3601 B and air reservoir IFA

3601 is also provided.

For Instrument air two set of air dryers are provided.




2011-06-11T12:27:19+0500ICET Students

agritech ltd internship report

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