In Plant Training Report

In FACT

Submitted by: Guided by:

C V Bhargava,

EEE,

Gitam University

Visakhapatnam. Joy Ukkan Manager

Training, FACT

Acknowledgement

I would like to take this opportunity to thank FACT for giving me such a

wonderful opportunity. I would like to express my sincere gratitude to all the

people who helped me along the way - Mr.T K.Unnikrishna Prasad, (Addl. Chief Engineer(Electrical Maintenance), Mr.Shajan (Elect Maintenance), Mr.Thampi Luther(Manager Maintenance), Mr.Anil Kumar (Chief Engineer,E&I, Petrochemical Division), Mr.Binny (Dy Chief Engineer(Electrical) Mr.Rajendran, Dy Chief Engineer(CPP), Mr PJ Mathew, DyChief Engineer(CPP) and Mr.Joy Ukkan(Manager,Training centre) - for their excellent guidance and support.

I would also like to thank all the other staff members of FACT who have directly or indirectly, helped me in this journey.

Contents

a) Introduction about FACT……….. 1

b) 110 KV substation………………. 6

c) Lightning arrestor……………….. 6

d) Electrical Isolator……………….. 9

e) Circuit Breaker………………….. 10

f) Current Transformer…………….. 11

g) Transformer……………………... 12

h) Captive Power Plant…………….. 14

i) Brief Chemical Processes………... 18

j) Motors……………………………. 19

k) Conclusion……………………….. 21

Introduction About FACT

Fertilisers and Chemicals Travancore Ltd. (FACT), a fertiliser and chemical

manufacturing company in Kochi, Kerala, India was incorporated in 1943. In 1947,

FACT started production of Ammonium Sulphate with an installed capacity of 50,000

MT per annum at Udyogamandal near Cochin. It is one of the largest chemical

manufacturing facilities in Kerala. The company has 2 production units - Udyogamandal

Division (UD) and Cochin Division (CD) .The Caprolactam plant was commissioned in

1990. Main products of the company are Factamfos (NP 20:20), Ammonium Sulphate

and Caprolactam. It also manufactures, as intermediate products, Ammonia, Sulphuric

Acid and phosphoric acid. Gypsum, Nitric acid and Soda ash are the major byproducts.

The factory commenced production of ammonium sulphate in 1947 at the dawn of Indian

independence using wood as the raw material for production of ammonia. With the

passage of time, wood gasification became uneconomical and was replaced with naphtha

reforming process. Through a series of expansion programmes, FACT soon became the

producer of a wide range of fertilizers suited for all crops and all soil types in India. It

became a Kerala State public sector enterprise in 1960 and in 1962, it came under the

Government of India. Diversification into full-fledged engineering services in the

fertilizer field and allied areas followed in the form of establishment of FEDO (FACT

Engg and Design Organisation) and FEW (FACT Engg Works). The next major step

forward was the diversification into petrochemicals, an important milestone in the growth

of the company. FACT has also formed a Joint Venture Company with Rashtriya

Chemicals & Fertilizers Limited for manufacturing load bearing panels and other

building products using phosphogypsum.

FACT Udyogamandal Plant, the oldest division of FACT, which started production of

Ammonium Sulphate in 1947 using the firewood gasification process, has during the last

few decades undergone several stages of expansion and diversification, giving up old and

obsolete technology and installing new and sophisticated plants making use of naphtha as

raw material. Today, the Udyogamandal Plants have an installed capacity of 76,050

tonnes of N and 29700 tonnes of P2O5. Apart from fertilisers like Ammonium Sulphate

and Ammonium Phosphate Sulphate (FACTAMFOS 20:20:0:13) FACT Udyogamandal

Plants also manufactures chemicals as intermediate products like Sulphuric Acid,

Anhydrous Ammonia, Sulphur Dioxide, Oleum, etc. Ammonium Sulphate liquor

obtained as a by product from the Caprolactam Plant is crystallised as a useful fertiliser

product in a New Ammonium Sulphate Plant of 2,25,000 TPA capacity put up in October

1990, at a cost of Rs.35 crore.

As a replacement to the old high energy consuming old Ammonia plants at

Udyogamandal, a new 900 TPD capacity Ammonia Plant at a cost of Rs.642 crore was

put up in March 1998. FACT Udyogamandal plants received ISO 14001 certification in

March 2000 for conforming to the Environmental Management System standard.

FACT’s Products:

a) Straight Fertilisers :

Ammonium Sulphate is a nitrogenous fertilizer containing 21% nitrogen, entirely in

ammonical form. It has excellent physical properties- crystalline and free flowing. It

is ideal as a straight nitrogenous fertilizer and also as an ingredient in fertilizer

mixtures. It is the most widely preferred nitrogenous fertilizer for top dressing on all

crops. Another unique advantage is that it contains 24% sulphur, an important

secondary nutrient.

b) Complex Fertilizer :

Factamfos 20-20-0-13 is a chemical blend of 40 parts of ammonium phosphate and

60 parts of ammonium sulphate. It contains 20% nitrogen and 20% P2O5. The entire

N is in ammonical form and P is completely soluble in water. In addition, Factamfos

contains 13% sulphur, a secondary plant nutrient which is now attaining great

importance in the agriculture industry.

c) FACT mix :

FACT prepares on a large scale all the standard NPK mixtures under the brand name

“FACTMIX” for different crops for Kerala as stipulated by the Department of

Agriculture. In addition, FACT prepares special tailor made fertilizer mixture of any

required grade for plantation crops like coffee, tea etc.

d) Caprolactam :

Caplrolactam is the raw material for nylon-6 which in turn is used in the manufacture

of tyre chord. The product quality of FACT’s caprolactam is among the best available

in the world.

e) Gypsum :

A by product of phosphoric acid production, gypsum is an ingredient in the

manufacture of Portland cement, plaster of paris, Gypcrete etc and also is used as

inert filler in Pharmaceuticals, paper, paints etc.

f) Imported Fertilizer :

FACT imports Urea and Potash from the gulf and Russia for the consumption in all 4

southern states as per requirement.

g) Bio Fertilizer :

Three types of bio fertilizers namely Azospirillium, Phosphobacter and Rhizobium

are produced and marketed as “BIO FACT”.

h) FACT Organic :

FACT is also marketing organic manure produced from city compust, in brand name

FACT Organic.

i) Zincated FACTAMFOS :

This special product containing 0.3% Zinc in FACTAMFOS has been launched to

address the wide spread deficiency of zinc in most soils in South India.

j) Zincated Gypsum :

This soil amendment and ameliorant contains 2% zinc in addition to 16% Sulphur and

22% Calcium for rectifying alkaline soils and improving soil fertility and physical

properties.

110 KV SUBSTATION

A substation is a part of an electrical transmission and

distribution system. Substations transform voltage from high to low, or the

reverse, or perform any of several other important functions. Between the

generating station and consumer, electric power may flow through several

substations at different voltage levels. Substations may be owned and

operated by an electrical utility, or may be owned by a large industrial or

commercial customer. Generally substations are unattended, relying on

SCADA for remote supervision and control.

A substation may include transformers to change voltage

levels between high transmission voltages and lower distribution voltages, or

at the interconnection of two different transmission voltages. The word

substation comes from the days before the distribution system became a

grid. As central generation stations became larger, smaller generating plants

were converted to distribution stations, receiving their energy supply from a

larger plant instead of using their own generators. The first substations were

connected to only one power station, where the generators were housed, and

were subsidiaries of that power station.

The layout or the outline of the 110 KV substation here is as shown.

A brief description of the components follows.

LIGHTNING ARRESTOR

A lightning arrester (in Europe: surge arrester) is a device used on electrical

power systems and telecommunications systems to protect the insulation and

conductors of the system from the damaging effects of lightning. The typical

lightning arrester has a high-voltage terminal and a ground terminal. When a

lightning surge (or switching surge, which is very similar) travels along the

power line to the arrester, the current from the surge is diverted through the

arrestor, in most cases to earth.

Operation:

A potential target for a lightning strike, such as a television antenna, is

attached to the terminal labeled A in the photograph. Terminal E is attached

to a long rod buried in the ground. Ordinarily no current will flow between

the antenna and the ground because there is extremely high resistance

between B and C, and also between C and D. The voltage of a lightning

strike, however, is many times higher than that needed to move electrons

through the two air gaps. The result is that electrons go through the lightning

arrester rather than traveling on to the television set and destroying it.

A lightning arrester may be a spark gap or may have a block of a

semiconducting material such as silicon carbide or zinc oxide. Some spark

gaps are open to the air, but most modern varieties are filled with a precision

gas mixture, and have a small amount of radioactive material to encourage

the gas to ionize when the voltage across the gap reaches a specified level.

Other designs of lightning arresters use a glow-discharge tube (essentially

like a neon glow lamp) connected between the protected conductor and

ground, or voltage-activated solid-state switches called varistors or MOVs.

Lightning arresters built for power substation use are impressive devices,

consisting of a porcelain tube several feet long and several inches in

diameter, typically filled with disks of zinc oxide. A safety port on the side

of the device vents the occasional internal explosion without shattering the

porcelain cylinder.

Lightning arresters are rated by the peak current they can withstand, the

amount of energy they can absorb, and the breakover voltage that they

require to begin conduction. They are applied as part of a lightning

protection system, in combination with air terminals and bonding.

ELECTRICAL ISOLATOR

Isolator is a mechanical switch which isolates a part of circuit from

system as when required. Electrical isolators separate a part of the system

from rest for safe maintenance works. So definition of isolator can be

rewritten as Isolator is a manually operated mechanical switch which

separates a part of the electrical power system normally at off load

condition.

Types:

There are different types of isolators available depending upon system

requirement such as:

a) Double Break Isolator

b) Single Break Isolator

c) Pantograph type Isolator

Depending upon the position in power system, the isolators can be

categorized as:

a) Bus side isolator – the isolator is directly connected with main bus

b) Line side isolator – the isolator is situated at line side of any feeder

c) Transfer bus side isolator – the isolator is directly connected with

transfer bus

Operation:

As no arc quenching technique is provided in isolator it must be operated

when there is no chance current flowing through the circuit. No live circuit

should be closed or open by isolator operation. A complete live closed

circuit must not be opened by isolator operation and also a live circuit must

not be closed and completed by isolator operation to avoid huge arcing in

between isolator contacts. That is why isolators must be open after circuit

breaker is open and these must be closed before circuit breaker is closed.

Isolator can be operated by hand locally as well as by motorized mechanism

from remote position. Motorized operation arrangement costs more

compared to hand operation; hence decision must be taken before choosing

an isolator for system whether hand operated or motor operated

economically optimum for the system. For voltages up to 145KV system

hand operated isolators are used whereas for higher voltage systems like 245

KV or 420 KV and above motorized isolators are used.

CIRCUIT BREAKERS

A circuit breaker is an automatically operated electrical switch designed to

protect an electrical circuit from damage caused by overload or short circuit.

Its basic function is to detect a fault condition and interrupt current flow.

Unlike a fuse, which operates once and then must be replaced, a circuit

breaker can be reset (either manually or automatically) to resume normal

operation. Circuit breakers are made in varying sizes, from small devices

that protect an individual household appliance up to large switchgear

designed to protect high voltage circuits feeding an entire city.

The type of CB used here is SF6 CB.

A sulfur hexafluoride circuit breaker uses contacts surrounded by sulfur

hexafluoride gas to quench the arc. They are most often used for

transmission-level voltages and may be incorporated into compact gas-

insulated switchgear. In cold climates, supplemental heating or de-rating of

the circuit breakers may be required due to liquefaction of the SF6 gas.

Operation:

All circuit breakers have common features in their operation, although

details vary substantially depending on the voltage class, current rating and

type of the circuit breaker. The circuit breaker must detect a fault condition;

in low-voltage circuit breakers this is usually done within the breaker

enclosure. Circuit breakers for large currents or high voltages are usually

arranged with pilot devices to sense a fault current and to operate the trip

opening mechanism. The trip solenoid that releases the latch is usually

energized by a separate battery, although some high-voltage circuit breakers

are self-contained with current transformers, protection relays, and an

internal control power source.

Once a fault is detected, contacts within the circuit breaker must open to

interrupt the circuit; some mechanically-stored energy (using something

such as springs or compressed air) contained within the breaker is used to

separate the contacts, although some of the energy required may be obtained

from the fault current itself. Small circuit breakers may be manually

operated; larger units have solenoids to trip the mechanism, and electric

motors to restore energy to the springs.

CURRENT TRANSFORMER

A current transformer (CT) is used for measurement of alternating electric

currents. Current transformers, together with voltage transformers (VT)

(potential transformers (PT)), are known as instrument transformers. When

current in a circuit is too high to directly apply to measuring instruments, a

current transformer produces a reduced current accurately proportional to the

current in the circuit, which can be conveniently connected to measuring and

recording instruments. A current transformer also isolates the measuring

instruments from what may be very high voltage in the monitored circuit.

Current transformers are commonly used in metering and protective relays

in the electrical power industry.

Operation:

Like any other transformer, a current transformer has a primary winding, a

magnetic core, and a secondary winding. The alternating current flowing in

the primary produces an alternating magnetic field in the core, which then

induces an alternating current in the secondary winding circuit. An essential

objective of current transformer design is to ensure that the primary and

secondary circuits are efficiently coupled, so that the secondary current bears

an accurate relationship to the primary current. A current transformer works

on the same principle as that of a simple transformer however it steps down

the high current into a low level so that it can be measured using an ammeter

of a suitable range. In some current transformers extra cores are provided.

This is done in order to prevent the faulty currents i.e. the over currents,

earth faults, differential protections. The extra cores of a C.T. gets saturated

as soon as the faulty currents starts flowing and thereby does not harm the

main core of the transformer and the ammeter connected. The C.T. is always

connected in the line carrying current. It first steps down the current to a

measurable form and further gives this current to the ammeter.

TRANSFORMERS

A transformer is a static electrical device that transfers energy by inductive

coupling between its winding circuits. A varying current in the primary

winding creates a varying magnetic flux in the transformer's core and thus a

varying magnetic flux through the secondary winding. This varying

magnetic flux induces a varying electromotive force (emf) or voltage in the

secondary winding. Transformers range in size from thumbnail-sized used in

microphones to units weighing hundreds of tons interconnecting the power

grid. A wide range of transformer designs are used in electronic and electric

power applications. Transformers are essential for the transmission,

distribution, and utilization of electrical energy.

Transformers are used to increase voltage before transmitting electrical

energy over long distances through wires. Wires have resistance which loses

energy through joule heating at a rate corresponding to square of the current.

By transforming power to a higher voltage transformers enable economical

transmission of power and distribution. Consequently, transformers have

shaped the electricity supply industry, permitting generation to be located

remotely from points of demand. All but a tiny fraction of the world's

electrical power has passed through a series of transformers by the time it

reaches the consumer. Transformers are also used extensively in electronic

products to step-down the supply voltage to a level suitable for the low

voltage circuits they contain. The transformer also electrically isolates the

end user from contact with the supply voltage. Signal and audio transformers

are used to couple stages of amplifiers and to match devices such as

microphones and record players to the input of amplifiers. Audio

transformers allowed telephone circuits to carry on a two-way conversation

over a single pair of wires. A balun transformer converts a signal that is

referenced to ground to a signal that has balanced voltages to ground, such

as between external cables and internal circuits.

Substation Operation:

The 110n KV supply from KSEB (Kerala State Electricity Board) is stepped

down to 11 KV in this substation. A further step down from 11 KV to 3.3

KV and to 433 V also occurs for the use of various loads.

There are two incoming feeders from the KSEB, one for main line and one

for standby. The bus is thus separated into two parts using a bus isolator or a

bus coupler. There are 4 main transformers, 2 for each feeder. For feeder

one, the transformers used are old and are of 15 MVA capacities each. For

the second feeder, the transformers are new and have on load tap changing

facility, and are of 20 MVA capacities. The 15 MVA transformers are oil

cooled whereas 20 MVA ones have forced air cooling facility.

For the distribution purpose, there are 3 switchboard panels as shown,

namely Jyoti panel, Alind panel and NGEF panel. Jyoti and Alind panels are

11 KV boards whereas NGEF panel is of 3.3 KV rating. Transformers 1 and

2 are connected to Jyoti as shown, and 3 and 4 to Alind.

There are 2 more transformers rated 11 KV/ 3.3 KV each with a capacity of

5 MVA. Two outlets, one each from jyoti and alind are given to these

transformers and the other ends are given to NGEF panel. From here, the

supply is distributed to various 3.3 KV motors. For the 11 KV loads, the

outgoings are from Alind panel.

Mainly 3.3 KV motors are used. Only one 11 KV motor is used, in ammonia

plant.

CAPTIVE POWER PLANT

Captive Power Plant in FACT is basically a Thermal Power Plant. As it is

working for the smooth functioning of Ammonia plant, it is known as a

Captive Power Plant. A thermal power station is a power plant in which the

prime mover is steam driven. Water is heated, turns into steam and spins a

steam turbine which drives an electrical generator. After it passes through

the turbine, the steam is condensed in a condenser and recycled to where it

was heated; this is known as a Rankine cycle. The greatest variation in the

design of thermal power stations is due to the different fossil fuel resources

generally used to heat the water. Some prefer to use the term energy center

because such facilities convert forms of heat energy into electrical energy.

Certain thermal power plants also are designed to produce heat energy for

industrial purposes of district heating, or desalination of water, in addition to

generating electrical power. Globally, fossil fueled thermal power plants

produce a large part of manmade CO2 emissions to the atmosphere, and

efforts to reduce these are many, varied and widespread. In FACT the main

fuel used is Furnace oil. As it is not that economical now they are modifying

the plant so that it can use Liquefied Natural Gas (LNG) as its fuel.

There are two captive plants. One producing a power of 16MW and other

producing a power of 6MW.Their voltage rating is 11kV and current rating

comes to around 1050Amps.

The 6 MW power plant is for ammonia plant and the 16 MW one is for the

petrochemical division (PD). There are two boilers for ammonia CPP and 3

for PD CPP.

In the Ammonia CPP, the turbine has a rated speed of 9000 rpm and the

generator is a 6 MW one with a synchronous speed of 1500 rpm.

Ammonia CPP :

WORKING:

Layout:

The CPP is basically used to provide supply to the critical equipment in the

plant. If KSEB supply was to be given to such equipment, in case of any

fluctuations, a tripping of the equipment could occur. This may trip the

whole plant. Restarting the plant would incur a lot of loss. Thus, to avoid

such fluctuations, a CPP actually acts as a UPS to the respected plant. The

whole working of the CPP is as discussed below:

The CPP used here is a steam power plant. This means that the turbine is

actually turned with the help of steam. This steam is produced from water.

The water is taken into DM tanks and de mineralized. This is done because

the water may have various minerals in it which may go on and contaminate

the boiler. Thus, the minerals and salts are removed from the water in the de

mineraliser.

The steam is now taken to the de aerator where the oxygen is removed from

it. This is because the oxygen may corrode the inner walls of the boiler.

Thus, it is necessary to remove the oxygen from the steam before letting it

into the boiler.

From the de aerator, the steam is sent to the economizer through 4

centrifugal pumps. The centrifugal pumps increase the pressure of the steam

as it goes through them. This is done so as to create a pressure difference

between the steam and the inside of the boiler, thus enabling the steam to

pass through. On its way to the boiler, the steam is heated in the economizer

and the pre heater. The economizer uses the heat from the flue gases and

heats the steam, thus utilizing the waste heat.

2 of the pumps are motor driven while the other two are steam driven.

There are 2 boilers in the Ammonia CPP and 3 in PD CPP. Inside the boiler,

the steam is pressurized to 110 atm, and 5250C. From the boiler, the steam is

sent to the turbine. But the steam isn’t let out all at once. The steam may

come at high pressure or may have moisture, either of which may result in

pressure building in the pipe and may result in the bursting of the pipe. Thus,

an isolator valve is used to let the steam out in steps and this maintains the

flow of steam into the turbine.

There are two other important valves that the steam has to pass through

before entering the turbine. The High Pressure Valve closes if the pressure in

the turbine goes too high and stops the steam from proceeding. The

Emergency Stop Valve closes and stops the steam if there is any difference

in the speed of the turbine or in the generator. The current in the generator is

actually converted to hydraulic pressure and this valve operates based on this

pressure.

The turbine used is both impulse as well as reaction turbine. Its volume is

gradually increased so as to decrease the pressure. Thus, in the first turbine,

there is one impulse blade and 11 reaction blades whereas in the second part,

there is 1 impulse blade and 9 reaction blades.

It is important to note here that the pressure of the steam is brought down

from 110 atm to 41 atm and the difference in the enthalpies between 110 atm

steam and 41 atm steam is used for producing electricity. This is becaue 41

atm steam is needed for various purposes in the CPP as well as in the

Ammonia plant.

The steam from the turbine is directed to the condenser where it is cooled

and collected in the hot well just below it. The pressure in the hot well is

maintained constant with the help of two centrifugal pumps, of which,

usually only one operates. The other pump operates only in case the pressure

deviates from the normal values.

Vaccum is created in the condenser so that it can absorb more steam from

the turbine and thus increase its efficiency. This vaccum is created in the

condenser using an ejector which sucks out the air/water from the condenser.

The condensed steam from the condenser and the ejector is sent to the DM

tank to be used again.

The turbine rotates at a synchronous speed of 9000 rpm as stated above. This

turbine is connected to a gear box of ratio 6:1 and reduces this speed to 1500

rpm and is connected to the generator shaft.

The generator is a synchronous generator. The field excitation is given to the

rotor which rotates and produces flux which induces an emf in the stator.

The power supply of 11 KV, 6 MW is taken from the stator.

To excite the rotor, we need a pilot exciter. The pilot exciter is nothing but a

permanent magnet generator ( 6 pole, 75 Hz, 220V ac). The supply from the

pilot exciter is given to an AVR (Automatic Voltage Regulator). The AVR

has a thyristor bridge rectifier which converts this 220 V ac to 120 V dc and

gives it to the ac exciter. The AVR checks for the voltage, pf, and current

and correspondingly increases or decreases the excitation, thus changing the

supply with respect to the load.

The ac exciter is another generator whose rotor is connected to the generator

rotor. The supply from the AVR is given to this rotor. The supply is given to

the armature and through induction, this supply is fed to the rotor of the

main generator. Thus, the rotor being excited and carrying current, induces

an emf in the stator and through the stator, we collect the supply using

tappings.

Protection System:

Oil is used for two main purposes here.

The first is the basic lubrication purpose. The oil is supplied to the bearing

and the rotating parts of the generator.

There are 3 main pumps here that are important to note, namely: The Main

Oil Pump (MOP), Auxiliary Oil Pump (AOP) and the Emergency Oil pump

(EOP).

The Main Oil pump is the only one among the above 3 that operates usually.

The MOP pumps the oil to the generator bearing etc and maintains the

pressure for the control of the steam entry to the turbine.

As we have seen earlier, the control of the pressure is actually through

hydraulic means in which, the control oil is fed to the servomotor which

converts it to electrical impulses which are again converted to hydraulic

pressure.

All these pressures are thus maintained based on the oil levels. If there is a

decrease in the pressure of oil, the AOP supplies the excess oil needed along

with the MOP. If in case, the AOP also fails, the turbine would come to a

stop. If this happens, the generator bearing would come to a sudden stop.

But this shouldn’t happen as it would result in the bearings getting burnt.

Thus, to prevent this, the EOP supplies oil to the bearings and thus they keep

rotating and do not come to an abrupt stop.

If in case the KSEB supply fails, all the equipment are run on the supply

from the t-g set. If the t-g set also fails, the power for the lights as well as for

the EOP is given from the Diesel Generator (DG) set. This is used only in

case of emergencies.

In case the DG also fails, there is an overhead tank that stores oil initially.

This tank provides oil to the generator bearings so that they do not come to

an abrupt stop.

Coupling of supplies:

Before the different supplies are coupled, we need to make sure that the

frequency, voltage and the phase sequence of both the supplies are the same.

If there is any change in any of the parameters, there could be burn out of the

grid.

PD CPP:

The main difference between the generators of the Ammonia CPP and the

PD CPP is that the PD CPP has a self exciting generator. It completely

avoids the pilot exciter.

Here, the rotor is excited through slip rings. Initially, the KSEB supply is

used to excite the generator. But once it starts producing power, some of its

own power is used to excite the rotor. This may add complexity to the circuit

by using a series compounding transformer and a neutral point, but it avoids

using the pilot exciter.

Also, the use of slip rings is not recommended since the brushes get burnt

after some uses. Thus, excitation through slip rings is disadvantageous.

A Brief description about the chemical process in the

manufacture of Ammonia:

A typical modern ammonia-producing plant first converts natural gas (i.e.,

methane) or LPG (liquefied petroleum gases such as propane and butane) or

petroleum naphtha into gaseous hydrogen. The method for producing

hydrogen from hydrocarbons is referred to as "Steam Reforming". The

hydrogen is then combined with nitrogen to produce ammonia via the

Haber-Bosch process.

Starting with a naphtha as feedstock (which will shortly be replaced with

liquefied natural gas), the processes used in producing the hydrogen are:

The first step in the process is to remove sulfur compounds from the

feedstock because sulfur deactivates the catalysts used in subsequent steps.

Sulfur removal requires catalytic hydrogenation to convert sulfur

compounds in the feedstocks to gaseous hydrogen sulfide:

H2 + RSH → RH + H2S (gas)

The gaseous hydrogen sulfide is then absorbed and removed by passing it

through beds of zinc oxide where it is converted to solid zinc sulfide:

H2S + ZnO → ZnS + H2O

Catalytic steam reforming of the sulfur-free feedstock is then used to form

hydrogen plus carbon monoxide:

CH4 + H2O → CO + 3H2

The next step then uses catalytic shift conversion to convert the carbon

monoxide to carbon dioxide and more hydrogen:

CO + H2O → CO2 + H2

The carbon dioxide is then removed either by absorption in aqueous

ethanolamine solutions or by adsorption in pressure swing adsorbers (PSA)

using proprietary solid adsorption media.

The final step in producing the hydrogen is to use catalytic methanation to

remove any small residual amounts of carbon monoxide or carbon dioxide

from the hydrogen:

CO + 3H2 → CH4 + H2O

CO2 + 4H2 → CH4 + 2 H2O

To produce the desired end-product ammonia, the hydrogen is then

catalytically reacted with nitrogen (derived from process air) to form

anhydrous liquid ammonia. This step is known as the ammonia synthesis

loop (also referred to as the Haber-Bosch process):

3H2+ N2→ 2NH3

The steam reforming, shift conversion, carbon dioxide removal and

methanation steps each operate at absolute pressures of about 25 to 35 bar,

and the ammonia synthesis loop operates at absolute pressures ranging from

60 to 180 bar depending upon which proprietary design is used.

A Brief description about the chemical process in the

manufacture of Caprolactum:

Caprolactam (CPL) is an organic compound with the formula

(CH2)5C(O)NH. This colourless solid is a lactam or a cyclic amide of

caproic acid. Caprolactam is the precursor to Nylon 6, a widely used

synthetic polymer.

Caprolactam is synthesised from cyclohexanone

(1) which is first converted to its oxime

(2) Treatment of this oxime with acid induces the Beckmann rearrangement

to give caprolactam.

The immediate product of the acid-induced rearrangement is the bisulfate

salt of caprolactam. This salt is neutralized with ammonia to release the free

lactam and cogenerate ammonium sulfate. In optimizing the industrial

practices, much attention is directed toward minimizing the production of

ammonium salts.

The other major industrial route involves formation of the oxime from

cyclohexane using nitrosyl chloride. The advantage of this method is that

cyclohexane is less expensive than cyclohexanone. In earlier times,

caprolactam was prepared by treatment of caprolactone with ammonia

MOTORS

There are two kinds of motors:

a) Synchronous motors

b) Induction motors

Only the Induction motors are used here. The generators used in CPP are

synchronous generators.

An induction motor is an asynchronous AC motor where power is

transferred to the rotor by electromagnetic induction, much like transformer

action. An induction motor resembles a rotating transformer, because the

stator (stationary part) is essentially the primary side of the transformer and

the rotor (rotating part) is the secondary side. Polyphase induction motors

are widely used in industry.

There are two kinds of Induction Motors :

SQUIRREL CAGE INDUCTION MOTORS:

SCIMs have a heavy winding made up of solid bars, usually aluminum or

copper, joined by rings at the ends of the rotor. When one considers only the

bars and rings as a whole, they are much like an animal's rotating exercise

cage, hence the name.

Currents induced into this winding provide the rotor magnetic field. The

shape of the rotor bars determines the speed-torque characteristics. At low

speeds, the current induced in the squirrel cage is nearly at line frequency

and tends to be in the outer parts of the rotor cage. As the motor accelerates,

the slip frequency becomes lower, and more current is in the interior of the

winding. By shaping the bars to change the resistance of the winding

portions in the interior and outer parts of the cage, effectively a variable

resistance is inserted in the rotor circuit. However, the majority of such

motors have uniform bars.

Slip Ring Induction Motors:

Slipring Induction motors have high starting torques. Their rotor is in the

shape of a slip ring connected to external resistance, varying which, the

speed can be controlled, hence the name. Slip ring induction motors are

costly and hence, nearly all the motors used in FACT are squirrel cage

induction motor.

Usually, for motors above 150 KW, we use star delta starters and for motors

below 150 KW, we use DOL (Direct Online starter). This is because DOL

starters are easy and less expensive to use. But the major disadvantage that

prevents it from being used for high power motors is that when it is started,

there is a dip in the line voltage. This happens because the starting current

drawn by the motor is high and hence, a large amount of voltage is needed.

Since this is supplied by the main supply, which is again connected to other

loads, the fluctuations caused may damage the other loads. Thus, for high

power motors, above 150 KW, we use star delta starters. For motors above

625 KV, we use auto transformer starter.

FEDO (FACT Engineering And Design

Organisation)

FEDO, a division of FACT, designs and selects the equipment for

purchasing depending upon the needs of the plants.

The Electrical wing of FEDO is given the list of motors or loads needed by

the mechanics. Depending upon this load, they select the equipment such as

the transformers, circuit breakers, motors, cables etc.

To design any electrical system, it is foremost important to know the load.

Once the load is provided, we get an idea on the capacities required for the

various equipment mentioned above. We also need to calculate the fault

level and make sure that the system is safe and has minimum losses possible.

Fault level:

The fault level is of great significance. The fault level is nothing but the

product of the system voltage and the fault current. The fault current is

calculated for various different faults to get the fault level.

The fault level is required to get an idea of the cables to be laid. When we

lay the cables, we make sure that they are able to sustain the current passing

through them. The current that normally passes is the Normal current. This

current rating is important for obvious reasons. But along with this, we need

to know that fault current. In case a short circuit occurs somewhere, a fault

current of a greater magnitude passes through the line. The line has to be

able to carry this current without breaking till the relay trips the trip circuit.

Thus, while laying the cables, we need to calculate the fault level.

The fault current is limited by the line impedance as well as the transformer

impedance. The impedance of the transformers used here is 12%.

One more important use for the fault level is the reduction in losses. Any

cable or line will have certain impedance. This causes a voltage drop in the

line. The higher this impedance, the higher the voltage drop. But this is not

good as it may cause fluctuations. Thus, we need to limit this impedance. To

do this, we need to reduce the length of the line or increase the cross section.

Since it is economical to reduce the length than increasing the cross section,

we place substations wherever possible. This helps to avoid these

fluctuations as well as is economical.

Design of motors:

Along with the transformers and cables, the motors also have to be designed.

The push buttons for the motors are to be placed in the switchboards and the

connections must be given to the motors from there. Since the actual

switching on and off of the motors takes place only at the location, an

ammeter has to be provided there for noting the load current.

The cables also have to be laid from the push buttons to the motors.

Interlocking systems have to be used sometimes. These are used in

conditions when the operation of one motor has to be dependent on another.

If one motor has to be switched on or off based on another motor,

interlocking system is used. This could be electrical or mechanical system.

Electrical systems consist of Boolean algebra and complex circuits. Here,

simpler mechanical systems are used.

Relays and Circuit Breakers:

Various relays have to be used for the protection of the generators and

motors. These relays are provided in the switchboards and have to be

provided with dc supply. The various relays are provided with code names

indicating their functions. Under voltage relay, over current relay, definite

time relay, negative sequence relay, under frequency relay are some

examples of the relays used here.

Various circuit breakers also have to be provided. The ammonia CPP uses

SF6 CBs whereas the 110 KV substation uses the new and more compact

Vaccum CBs. The old panels use the huge and large air CBs while in come

cases, like in PD CPP, Minimum Oil CBs are used.

CONCLUSION

The whole of generation, transmission and distribution of Electric Power for

the operation of various motors in plants was thoroughly studied. The

synchronous generators are coupled with the KSEB supply, matching the

frequency, phase sequence and the voltage of both the lines and then

distributed to the various parts.

The critical equipments in the plant are driven by the power from CPP

whereas all the other equipments are driven by the power from KSEB. The

billing aspects of KSEB have also been studied and it has been learnt that

FACT comes under the bulk consumer part.

An in depth study has been made about the various aspects involved in

distribution from the substation. Different kinds of CBs are used depending

upon when the section of the plant was established or the needs of the place.

The theory learnt at the classroom level has been well complemented in the

training. Under the guidance of the respected sirs, it has been a rich learning

experience as a student and a thoroughly enjoyable one.