VISVESVARAYA TECHNOLOGICAL UNIVERSITY

Jnana Sangama, Belagavi-590018, Karnataka, India.

INTERNSHIP PRACTICE REPORT

Submitted in Partial Fulfilment for the Award of Degree of

Bachelor of Engineering
in

Electronics and Communication Engineering

SUBMITED BY
Ms. PRANEETHA V.NAYAK 2KL16EC053

Internship Carried out at

Grasim Industries Limited, Karwar

Internal Guide External Guide

Shewta Madiwalar Umesh C. Nayak
Professor HOIC
KLE Dr.MSSCET Grasim Industries Ltd

SEMESTER: VIII
(2020)

K. L. E. Dr. M. S. SHESHGIRI COLLEGE OF ENGINEERING AND TECHNOLOGY DEPARTMENT OF

ELECTRONICS AND COMMNUNICATION ENGINEERING 2019-2020
 K. L. E. Dr. M. S. SHESHGIRI COLLEGE OF ENGINEERING
AND TECHNOLOGY, BELGAVI – 590008.

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

ENGINEERING

CERTIFICATE

This is to certify that the “Internship/Professional Practice Report” submitted by

Ms.PRANEETHA V. NAYAK 2KL16EC053, bonafide students of K.L.E. Dr. M. S.
Sheshgiri College of Engineering and Technology, Belagavi, in partial fulfilment for the
award of Bachelor of Engineering in Electronics and Communication Engineering of
Visvesvaraya Technological University, Belagavi, during the academic year 2019-20.It is
certified that all corrections/suggestions indicated for internal assessment have been
incorporated in the report. The report of internship/Professional practice has been approved
as it satisfies the academic requirements in respect of internship prescribed for the said
degree.

Signature of Guide Signature of H.O.D (Prof.Shewta

Madiwalar) (Dr.Rajashri Khanai)
Acknowledgement
I take this opportunity to express my sincere gratitude to the people who have been helpful in the successful
completion of my industrial training and this project. I would like to show my greatest appreciation to the
highly esteemed and devoted technical staff, supervisors of the Grasim Industries Limited, Karwar. I am
highly indebted to them for the tremendous support and help during the course of my training.

I am grateful to Mr. S.K. Bhatt Sir, Head of HR and Mr. Jaganivas Raghavan Sir, HR Manager who granted
me the permission of industrial training in the company. I would like to thank Mr. Umesh Nayak Sir, H.O.D
(Instrumentation dept.) for personally being my mentor, Mr. Uday Naik Sir, Dept. Manager (Instrumentation
Dept.) and Mr. Vinod Patil , Asst. Manager ( Instrumentation Dept.) for their valuable guidance and
knowledge they shared without which it would have been difficult for me to complete my training. I would
also like to express my gratitude to Mr. Chandan Nayak, Mr. Aushutosh Diwedi and Mr. Ravi Saini who
helped me a lot in understanding the various processes and concepts involved. Also I wish to extend my
sincere thanks to all those who directly or indirectly helped and guided me to complete my training
successfully. It was an immensely informative experience having training in Grasim Industries Limited,
Karwar and learning fr88om such experienced engineers.

I also thankful to my college guide Prof.Shewta Madiwalar ma’am for giving valuable inputs and guiding
through the path for this Internship.
VISION OF THE INSTITUTE

To be an organization of excellence, leveraging human potential in engineering and

Management for a better tomorrow.

MISSION OF THE INSTITUTE

1. To nurture scientific temperament through the process of intellectual stimulation.

2. To excel in academic and research endeavors.
3. To facilitate employability, entrepreneurial ability along with social responsibility.
4. To inculcate a sense of life-long learning.
5. To collaborate with institutions and industries for excellence.

VISION OF THE DEPARTMENT

To impart quality education in the field of Biomedical science by applying engineering

principles.
MISSION OF THE DEPARTMENT

1. To achieve academic excellence by applying biomedical engineering knowledge.

2. To adapt emerging technologies in biomedical engineering through continual learning.
3. To acquire the knowledge of medical instrumentation through engineering and related R & D
activities.
4. To work with hospitals and healthcare industries to enhance practical knowledge.
5. To develop competencies for employability and entrepreneurship in core and interdisciplinary areas.
Program Educational Objectives (PEOs) of Department

1. Apply the engineering concepts to maintain biomedical equipments and develop

medical software.
2. Exhibit technical competence by upgrading their knowledge in Biomedical Engineering.
3. Inculcate the sense of social responsibility and practice ethics to work with varied groups.

Program Specific Outcomes (PSOs) of Department

1. Acquire proficiency in the field of medical instrumentation, signal & image

 processing and hospital management.
2. Attain employability in Biomedical engineering and associated fields.
3. Exhibit professional communication and team building skills through seminars, projects, workshops,
hospital survey and internships.
Program outcomes (POs)
PO1. Engineering knowledge: Apply the knowledge of mathematics, science, engineering fundamentals, and an
engineering specialization to the solution of complex engineering problems.

PO2. Problem analysis: Identify, formulate, review research literature, and analyze complex engineering problems
reaching substantiated conclusions using first principles of mathematics, natural sciences, and engineering sciences.

PO3. Design/ development of solutions: Design solutions for complex engineering problems and design system
components or processes that meet the specified needs with appropriate consideration for the public health and
safety, and the cultural, societal, and environmental considerations.
PO4. Conduct investigations of complex problems: Use research-based knowledge and research methods
including design of experiments, analysis and interpretation of data, and synthesis of the information to provide valid
conclusions.
PO5. Modern tool usage: Create, select, and apply appropriate techniques, resources, and modern engineering
and IT tools including prediction and modeling to complex engineering activities with an understanding of the
limitations.
PO6. The engineer and society: Apply reasoning informed by the contextual knowledge to assess societal,
health, safety, legal and cultural issues and the consequent responsibilities relevant to the professional
engineering practice.
PO7. Environment and sustainability: Understand the impact of the professional engineering solutions in
societal and environmental contexts, and demonstrate the knowledge of, and need for sustainable
development.
PO8. Ethics: Apply ethical principles and commit to professional ethics and responsibilities and norms
of the engineering practice.
PO9. Individual and team work: Function effectively as an individual, and as a member or leader in diverse
teams, and in multidisciplinary settings.

PO10. Communication: Communicate effectively on complex engineering activities with the engineering
community and with society at large, such as, being able to comprehend and write effective reports and design
documentation, make effective presentations, and give and receive clear instructions.

PO11. Project management and finance: Demonstrate knowledge and understanding of the engineering and
management principles and apply these to one’s own work, as a member and leader in a team, to manage
projects and in multidisciplinary environments

PO12. Life-long learning: Recognize the need for, and have the preparation and ability to engage in independent and
life-long learning in the broadest context of technological change.

`Table of Contents
 Sl.no Contents Pg.no

1. Executive Summary 1
2. About the Company 2
3. Instrumentation and Control 4
4. Internship Objective 5
5. Tasks/Activities Performed 6
6. Conclusion 18
7. Bibliography 19

1.Executive Summary
Grasim, the flagship company of the $48.3 billion Aditya Birla Group, is a global player with solid presence
across the globe. Grasim Industries was ranked 154th in a list of the world's best regarded firms compiled by
Forbes.The company initially belonged to the Solaris ChemTech Industries Limited. Later the Aditya Birla
Group took over the Karwar chemical division to make a strong foothold in the southern region in
production of phosphoric acid and caustic soda. The company is mainly engaged in the production of two
chemicals-caustic soda (NaOH) and phosphoric acid (H3PO4). The entire plant is thus divided into two —
Phosphoric acid plant and caustic soda plant. Hydrochloric acid and hypo are some of the by-products which
is also sold.

The whole process of caustic soda and was explained then. The raw materials required for the preparation is
NaCl and water. A brine solution is prepared by mixing the two. This brine solution is then sent to the
electrolysers where membrane cells are present having nickel as cathode and coated titanium as anode.
When current is made to pass, the sodium ions comes out as catholyte and gives out 32% caustic chlorine
gas at anode. This way 32% caustic soda is obtained. The electrolysers are provided approximately 560 dc
voltage. This leads to breaking of Na + ions which mixes with the water molecules to form NaOH and
chlorine is released. This caustic soda is further concentrated to 48% in CCU unit.

Chlorine is further washed, cooled by chilled water and dried using H 2SO4. Then it is compressed and
liquefied using Freon as refrigerant. The chlorine produced is further used in manufacturing of HCl which is
another product used in phosphoric acid plant too as a raw material. It is prepared in a furnace by burning
hydrogen and chlorine at high temperatures. As a result 38% HCl acid is obtained.

Hypo is another product made here using caustic soda and chlorine. Caustic soda is sprinkled on chlorine
which results in hypo sodium hypo formation (NaClO). It is a critical product and is thus directly
transported.

2.About The Company:Grasim Industries Limited

In 1972, Grasim’s chemicals business was set up to manufacture caustic soda for the company’s VSF unit.
Today, it is one of India’s largest caustic soda producers and is a market leader in the chlor-alkali segment. 
Over the years, Grasim’s chemicals business has created a strong foothold in the industry and offers a wide
range of products from chlorine derivatives to epoxy.

Chlor-alkali
In 2016, Grasim’s merger with Aditya Birla Chemicals India Ltd. (ABCIL) helped catapult the company’s
caustic soda capacity from 452 KTPA to 884 KTPA making it the largest producer of caustic soda in India
back then. Today, Grasim’s total caustic soda capacity is 1,147 KTPA. In FY19, the chlor-alkali business
achieved 1 million tonnes of caustic sales entering the ivy league of top 10 businesses in the sector globally. 

The business uses cost-effective membrane cell technology and is largely self-sufficient in power. For
gainful utilisation of chlorine, the business has portfolio of chlorine derivatives like Stable Bleaching
Powder (SBP), Polyaluminium Chloride (PAC), Chlorosulphonic Acid (CSA), Chlorinated Paraffin Wax
(CPW), Calcium Chloride (CaCl) and Aluminium Chloride (AlCl).

Tasks Performed
The raw materials required for the preparation is NaCl and water. A brine solution is prepared by mixing the
two. This brine solution is then sent to the electrolysers where membrane cells are present having nickel as
cathode and coated titanium as anode. When current is made to pass, the sodium ions comes out as catholyte
and gives out 32% caustic chlorine gas at anode. This way 32% caustic soda is obtained. The electrolysers
are provided approximately 560 dc voltage. This leads to breaking of Na + ions which mixes with the water
molecules to form NaOH and chlorine is released. This caustic soda is further concentrated to 48% in CCU
unit.
Chlorine is further washed, cooled by chilled water and dried using H 2SO4. Then it is compressed and
liquefied using Freon as refrigerant. The chlorine produced is further used in manufacturing of HCl which is
another product used in phosphoric acid plant too as a raw material. It is prepared in a furnace by burning
hydrogen and chlorine at high temperatures. As a result 38% HCl acid is obtained.
Hypo is another product made here using caustic soda and chlorine. Caustic soda is sprinkled on chlorine
which results in hypo sodium hypo formation (NaClO). It is a critical product and is thus directly
transported.
All the pipelines carrying the chemicals have been colored as per the colour code of the chemical they are
carrying. The colour codes are as follows
 DM Water- Green
 Process water/ chilled water- Deep green
  Brine- cyan
 Instrument air/ plant air/ nitrogen- blue
 Chlorine- yellow
 Hydrogen- red
 Steam- brown
 Caustic soda 32%- magenta
 HCl/ H2SO4- orange
 Hypo- yellow
 Furnace oil- black

2.1:Values of the Company

3.Department:Instrumentation and Control

Instrumentation is used in managing, maintaining, controlling, modifying existing system, automation of
instruments for the effective working of the plant
The main two things done by the department is — i) Measurement and ii) Control. The need of
instrumentation in plant is due to following reasons:

 Minimise energy and maximise quantity

 Supremacy of product depends on the market quality of the products maintained by automation used in
the industries. There is no automation without control system without automation.

The main physical parameters to be measured are as follows-

1. Pressure
2. Temperature
3. Flow
4. Level
5. Conductivity and ph
6. Turbidity

The various field control elements present are ON/OFF valves, linear and equal percentage valves, variable
frequency drives (VFD), solenoid valves and many more. The basic works involves

 Installation
 Electrical wiring
 Termination of I/O panel
 Configuration of DCS as well as transmitters
 Logic check
 Loop check
 Calibration

4.Internship Objective
The objective of the internship in the Instrumentation and Control Department in the Chemical Industry was
to understand the installing, managing, calibrating and maintaining equipment and also configuration and
automation of the systems which is used to monitor and control engineering system in the industry.

5.Tasks/Activities Performed
My internship was focused on instrumentation and control of the company where it plays a major part on
working of a multitier company.

Instrumentation and measurement

The measurement of various parameters being one of the most important thing to be done is accomplishes
using transmitters. The various transmitters used are pressure transmitters, differential pressure transmitters,
flow transmitters, level transmitters, temperature transmitters, and others. The transmitters used are bought
from Rosemount, Yokogawa, ABB and others. These transmitters are periodically calibrated using HART
hand held calibrator. These transmitters give out 4-20 mA as output which corresponds to 0-100% output.
Indicators are also present to give local indications of the parameters. E.g. pressure gauges, temperature
gauges, rotameters etc. There are various detectors also installed for critical conditions such as chlorine
detectors, H2 detectors and flame detectors. These automatically initiate alarms when in critical situations.

Temperature measurement and control

We started with measurement of temperature. The process temperature to be measured is done using
thermocouples, RTDs and pyrometers. Temperatures with normal temperature range, i.e., below 300° C are
measured using RTDs and for higher temperature ranges thermocouples are used. RTDs can be made of
three material- i) copper, but it can easily oxidised, ii) nickel RTDs which is used when measuring
temperatures below 100°C , iii) platinum RTDs for higher ranges. Platinum RTD pt-100 is the widely used
RTD due to its linear response and faithful output.

Widely used thermocouples are J type, K type, R type, S type or T type. In case of RTDs, the output is
varying resistance with the temperature. In thermocouple, output is in millivolts.

RTD gives output via 3-wire communication while in case of a thermocouple 2-wire communication is
there. These temperature measuring devices cannot be made to have direct contact with the process fluids
and so a thermowells are used inside which they are kept. These thermowells are made up of stainless steel
or tantalum which can withstand high corrosive and temperature conditions and not let the RTDs or
thermocouples to get damaged. The thermowells are filled with glycerine so that water doesn’t get inside it.
The temperature gauges have bimetallic strip which works on the principle of expansion and compression of
metals with varying temperature. Where only local indication is required, gauges can be used.

The RTDs and thermocouples are connected to the transmitters which convert the resistance and millivolts
input to 4-20 mA output. This output is next sent to the DCS system where the values are shown and
controllers are next given required signal to achieve the required set point.
 Resistance Temperature Detector (RTD)

Calibration of RTDs and Thermocouples

It is done using HART hand held calibrator. A RTD or thermocouple is connected to a transmitter via 3-wire
and 2-wire connection respectively. A calibrator is connected to the supply connection of the transmitter and
the calibrator initiates with showing the information about the transmitter. Various parameters such as the
unit in which the measurement is to be shown, the lower and upper range, the name of the transmitter and
manual calibration etc. can be done using the calibrator. The calibrator used here is of yokogawa. The output
value shown will be in 4-20 mA values which will correspond to 0-100%. Calibration is done at fixed values
for span adjustment, i.e. , at 4, 8, 12, 16 and 20 mA for 0, 25, 50, 75 and 100% reading of the measuring
device. If values deviate from these values then calibration is done and again the same procedure is repeated
until proper readings obtained. After calibration, a tag is attached to the transmitter showing the calibration
date and time.
The certification of calibration consists of:
 Calibration organisation
 Certification title
 Item identification
 Requestor
 Calibration due date
 Calibration no.
 Signature

And thus we can get the information about the calibration of any particular device by looking at the tag.

Pressure and differential pressure measurement

Pressure measurement can be done using various devices such as bourdon tube, diaphragm gauges, bellows,
manometers and many more. For local indication of pressure, pressure gauges with diaphragms or bourdon
tube may be used. Differential pressure can be measured using orifice plates and the two tapping values can
be given to a smart transmitter. The transmitter shows the differential pressure values in the form of 4-20
mA for 0-100% span value. This transmitter output is sent to the DCS where a control signal using the
controller can be send in order to obtain the desired output.
For obtaining pressure reading, only one tapping can be used and connected to a transmitter. A siphon is
used protect the pressure sensor from high-temperature media, such as steam. It is also used to reduce the
potentially damaging effects of rapid pressure changes. It is filled with liquid which prevents the direct
contact with high temperature steam.

Calibration of pressure gauges and transmitters

The most accurate device for calibrating all the pressure gauges to the accurate values is a dead weight
pressure tester. The transmitters are calibrated by giving known pressure pneumatic signal to the inlet of the
transmitter and observing if the output shown is in correspondence with the signal. If not so, it can be
calibrated using a HART hand held calibrator. And similarly all the pressure measuring devices can be
calibrated.

Flow measurement
Flow measurement in the plant is undergone using rotameters, vortex flowmeters, magnetic flowmeters,
mass flowmeters and orifice plates etc. Rotameters are of two types- glass tube and metal tube. The metal
tube rotameters are accompanied with contact switches which open/close on reaching a desired flow rate.
These switches send a signal to the DCS and thus the operator is alerted about the flow rate. This can thus
send a feedback to control valve in order to vary the opening of the valves to control the flow rate. The
magnetic flowmeters are basically used to measure the flow rate of conducting liquids. 110V supply is given
to the flowmeter to create a flux around the pipe. As per the flow rate of the fluid, emf is induced which is
measured and given output in terms of 4-20 mA. Vortex flowmeters are used in liquids which on coming in
contact with an obstacle creates vortices. These vortices created vary as per the flow rate of the liquid and a
piezoelectric transducer converts this mechanical force to 4-20 mA. Thus flow rate can be measured. In
mass flowmeters works on the principle of Coriolis force. Fluid is made to pass through uniformly vibrating
pipe. As per the flow rate, it bends slightly and the rotation is not uniform. As the amount of twist is
proportional to the mass flow rate of fluid, it is measured to give output reading in electrical form. Orifice
plates provide an obstruction to the flow of liquids and works on the principle of Bernoulli’s theorem. The
differential pressure obtained by taking pressure readings from two tapings gives us the flow value. The
tapings are always placed at the beta ratio which is at distances D and 0.5D where D is the diameter of the
pipe containing the liquid. The shape of the orifice plate varies as per the liquid flowing. For normal fluids,
concentric plates are used. For heavy liquids, syrups and slurries, quadrant type plated are used. Other types
of plates are eccentric and segmental. Orifice plate is usually used for liquids that are corrosive.
 Vortex Flow Meter Magnetic Flow Meter

Calibration Of Flow Meters

The smart transmitters to which the differential pressure readings are given can be easily calibrated by
giving differing pneumatic supply and setting the output reading to the appropriate values using HART hand
held calibrator.

Level Measurement
For level measurement devices such as magnetic level meter, float type level meter, radar type level
transmitter, flash mounted level transmitter, dip tube level transmitter and ultrasonic level meter. Level of
sludge or liquids which is having high corrosive nature can be measured using radar type level transmitter.
For open tanks, flash mounted level transmitters can be used. Magnetic level meter contains magnetic reeds
that flip when comes in vicinity of magnetic float suspended in the liquid and thus gives reading of the level.
Radar type transmitter makes use of the microwaves which are reflected back when comes in contact with
the liquid surface and the time taken by the wave to come back is counted using a timer an gives output in
the form of 4-20 mA. Thus liquids whose level is to be measured without contact, radar type can be
installed. In flash mounted, at the empty point, transmitter is mounted which gives the level reading. The
level is measured by measuring the pressure and density of the liquid inside it. In a dip tube level
transmitter, air purging system is used. It is used for corrosive liquids where the fluid can harm the
transmitter. It consists of an AFR (air filter regulator), an air purge system and a transmitter. Purge air is sent
through a pipe to the fluid and thus a back pressure is created as per the pressure of the liquid and gives
reading to the transmitter. The transmitter gives 4-20 mA reading to the DCS. The H 2SO 4 tank makes use of
this level meter as it is corrosive. The effluent plant where the slurries’ level is to be measured makes use of
the radar type level meter. In the chlorine filling status, magnetic float type level indicator is used. For most
of the non corrosive liquids, rotameters are used.

pH meters and conductivity meters

Measuring the pH of the liquids especially the DM water is necessary and is done using a pH meter. It
basically measures the potential of the hydrogen ions. It consists of electrodes which is a glass electrode and
a reference electrode. The electrode consists of KCl and a silver suspended wire. The H +
ions from the
electrode and the ones generated by the ions of the solution creates a potential difference and gives reading
in mV. This helps in getting the pH values. Here the pH meter used are from FLEXA which simultaneously
gives the temperature reading too. Conductivity meters are meant for measuring the conductivity of the
liquid which is the reciprocal of the resistivity. It can be measured by measuring the conductance of the
liquid and finding the product with the cell constant which depends upon the electrodes area and distance
between them. It is measured in µ Siemens. More the no. of ions more will be the conductivity of the fluid.
It is used for measuring the conductivity of the caustic soda (NaOH).

Positioners

A positioned is a device put into a valve to ensure that it is at a correct position of opening as per the control
signal. In caustic plant, everywhere smart Positioners are being used which has the auto tuning facility and
contains integrated I/P converter inside it. They give feedback too of the opening of the valve in 0-100%.
Siemens Positioners are mostly used here. They are calibrated by giving known controller input and
measuring the feedback signal and setting the output pneumatic to required levels.

Photocell amplifier

In the furnace, H 2 and Cl2 are burnt at high temperatures to give out HCl. H2 being a highly flammable gas if
catches flame could lead to accidents. Thus a flame detector is installed in the furnace which on finding a
flame receives UV rays and thus initates the NC/NO logic as per the settings. This opens the valve of the
nitrogen to purge the flame. Thus the process can be monitored.

Load cells

Load cells are used to measure the weight or pressure exerted by a body. It is utilised at the chlorine filling
station in the plant to measure the weight of the chlorine cylinders. It consists of strain gauges. It consists of
resistance foil and ceramic metal membrane. Four strain gauges are aligned at the four corners and are
connected in a Wheatstone bridge form. On application of pressure on the gauge, its resistance changes as it
expands and thus the voltage across the two ends vary which gives reading for weight of the object.

Variable frequency drive

It acts a final control element to vary the speed of motors. It varies the frequency of the signal keeping the
other parameters constant. The signal obtaining from the control room which is 4-20 mA varies the
frequency likewise. This signal from the control room is obtained via Profibus communication.

Relays

Relays are switches that open and close circuits electromechanically or electronically. Relays control one
electrical circuit by opening and closing contacts in another circuit. When a relay contact is normally open
(NO), there is an open contact when the relay is not energized. When a relay contact is Normally Closed
(NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to
the contacts will change their state. Relays are generally used to switch smaller currents in a control circuit
and do not usually control power consuming devices except for small motors and Solenoids that draw low
amps. Nonetheless, relays can "control" larger voltages and amperes by having an amplifying effect because
a small voltage applied to a relays coil can result in a large voltage being switched by the contacts. 
Protective relays can prevent equipment damage by detecting electrical abnormalities, including over-
current, undercurrent, overloads and reverse currents. In addition, relays are also widely used to switch
starting coils, heating elements, pilot lights and audible alarms. 

CURRENT TO PRESSURE CONVERTER (I/P CONVERTER):

A “current to pressure” (I/P) converter converts an analog signal (4 to 20 mA) to a proportional linear
pneumatic output (3 to 15 psig). Its purpose is to translate the analog output from a control system into a
precise, repeatable pressure value to control pneumatic actuators/operators, pneumatic valves, dampers,
vanes, etc.
WORKING OF I/P CONVERTER:

If the current is more, then the power of magnet will get increased. The Flapper of the  Flapper-
Nozzle instrument is connected to Pivot so that it can move up and down and a magnetic material was
attached to other end of flapper and it is kept near the electromagnet. As the magnet gets activated .The
flapper moves towards the electromagnet and the nozzle gets closed to some extent. So the some part of 20
P.S.I supplied will escape through nozzle and remaining pressure will come as output.
If the current signal is high, then power of the magnet will increase, then flapper will move closer
to the nozzle, so less pressure will escape through nozzle and output pressure increases .In this way the
output pressure will be proportional to the input current .For the input current of 4-20 mA we can get the
output pressure of 3-15 P.S.I

How to convert 4-20mA current into voltage?

If we want to convert 4-20mA current into voltage then ,according to Ohm’s law we V=IR .Therefore by
multiplying the current with some resistance we can convert current to voltage .Here we are multiplying
current with 250ohm resistance.

HIGHWAY ADDRESSABLE REMOTE TRANSMISSION (HART):

 It is an important tool in instrumentation. HART is a two way communication device. Using
this device we can adjust some of the values in the devices as desired.“HART” is an acronym for
Highway Addressable Remote Transducer. The HART is used to superimpose digital communication
signals at a low level on top of the 4-20mA. This enables two-way field communication to take place
and makes it possible for additional information beyond just the normal process variable to be
communicated to/from a smart field instrument.

The HART Protocol provides two simultaneous communication channels: the 4-20mA analog
signal and a digital signal. The 4-20mA signal communicates the primary measured value (in the case
of a field instrument) using the 4-20mA current loop - the fastest and most reliable industry standard.
Additional device information is communicated using a digital signal that is superimposed on the
analog signal. 

The digital signal contains information from the device including device status, diagnostics,
additional measured or calculated values, etc. Together, the two communication channels provide a
low-cost and very robust complete field communication solution that is easy to use and configure.  

PID CONTROLLER (PROPORTIONAL-INTEGRATION-DERIVATIVE):

A proportional-integration-derivative controller is a control loop feedback mechanism widely used on

industrial system .A PID controller continuously calculates the difference between Set-point and the
process variables and applies the correction based on proportional-integral-derivative terms .In this
plant only proportional and derivative is used .Firstly some random value of P and D is selected and
then the trend is observed ,then the value of P and D is again varied and trend is observed comparision
will be done between these two and based on it the values are adjusted until very low fluctuation is
observed

The Control System

DIGITAL CONTROL SYSTEM: Digital control system uses microprocessor to do the control function. In
a digital control system the parameter are measured by transmitter. The transmitter generates 4-20mA
current signal corresponding to 0-100%.This signal is converted by signal converter into voltage
signal .Analog to digital converters are used to convert analog signal to digital signal .This digital signal is
given to microprocessor for processing .Digital control system use microprocessor to do the control
functions. The DCS system here for monitoring and controlling is Yokogawa Centum VP. It’s the latest
DCS system of Yokogawa. The communication is through Vnet/IP. The speed of communication is 1GBps.
The hardware consists of

 Power supply
 Controller (CPU)
 Analog I/O
 Digital I/O
 Communication module

The different types of panels are:

i. Auxiliary cabinet
ii. PDB cabinet
iii. DCS system cabinet (having controllers)
iv. Marshalling cabinets
v. Digital marshalling cabinets

The software can be accessed by two segments: control builder and graphic builder. The graphic designer
provides the HMI to the program while the control builder can build the interlocks required. There are three
types of user: ON, OFF and ENGG.

The ON users which are the operators can only view the graphics and change certain parameter values. The
OFF users can only view the graphics. The ENGG can change the parameter values, modify the programs
and interlocks and also change the graphics. The connection of the transmitters to the DCS panel is via a 2-
wire communication. All the 4-20 mA signals are sent through a multicore cable to a junction box. These
output of the transmitters is sent to the panel. This signal is next sent to the YBNC through which it is sent
via prefab cable to a module where indications are seen if the device is active. Then the signal is converted
to analog signal and sent to the controller where the set value is given. The signal is then again send to the
module after which the analog converted signal is sent to the final control element. Thus this is how a DCS
works. In case of digital signal, relays are used for controlling purposes.

There are various interlocks prepared in the DCS, i.e., when a particular condition is true/false, another
action is to be performed. It is a critical procedure as most of the working of the processes is due to the
interlocks and the whole plant might trip by just one interlock activation. Thus it is prepared with utmost
care.

Here in caustic soda plant, three modules are present:

 ADV151- for digital input

 AAB841- for analog i/o
 ADV551- digital o/p

The readings of the voltage of cells in the electrolyser and also the voltage between two cells are
continuously monitored in an excel sheet. Three operator consoles are present, one for specifically
monitoring the electrolyser voltage. Thus this is how the controlling procedure is carried out.

DISTRIBUTED CONTROL SYSTEM(DCS):In Distributed Control System, the control is distributed,

but the monitoring is still centralized. All the n field inputs are not fed to a single CPU. Instead they are
distributed among multiple CPU’s .In DCS terminology, CPU’s are referred as Field Control Stations (FCS)
Advantages of DCS:

 Control function is distributed among multiple CPU’s (FCS).Hence failure of one FCS doesn’t affect
the entire plant.
 Redundancy is available at various levels.
 Maintenance and troubleshooting becomes very easy.
 Cost effective in the long run.

BASIC COMPONENTS IN DCS:

ENGINEERING/OPERATOR STATION :From which the operator controls the plant and the
same component can also be used to do configuration changes .The operator station or the Man
Machine interference (MMI) is called the Human Interference Station(HIS).While the components
used for configuration are called the Engineering station(ENG station is PC loaded with engineering
software).
THE FIELD CONTROL STATION (FCS):It is the interface between the Field instruments and
the control room .This is the component where all the control functions are executed and hence is a
very important and critical component in the overall system.
COMMUNICATION BUS: The above two components connected via real time control network
which communicates all the parameters to and from the Field Control Station to the Human
Interference Station.

HUMAN INTERFERENCE STATION(HIS):HIS acquires process variable , events ,alarms from the
Field Control Station (FCS) and send set points and output to the FCS .This monitoring and control
operation is done using user-defined Graphics panels. The number of HIS is decided based on the number of
operators required to control the process plant

DETAILS OF FIELD CONTROL STATION(FCS):

The FCU consists of two processor cards, two power supply units along with battery units and two
bus interference cards .Additionally ,the FCU also consists of power I/O terminal to connect the main power
to the FCU .Power distribution panel is used to distribute the power to the Power supply units .Fan units to
maintain FCU temperature and air filters to filter the dust.

Processor card: There two processor cards .It is nothing but CPU it consists of the programs that are
required for controlling the process .The processor card itself contains a battery if incase the power supply is
not available then this battery will provide backup of 72 hours. Up to 72 hours whatever programs that is
coded will be retained.

Battery unit: The type if battery used here is Cadmium Lithium .There are two battery units .The life time
of the battery changes according to the ambient temperature .As for battery output, the left battery unit
backups the left CPU and the right side of the battery unit the right CPU .In a single unit the battery unit is
installed on the left side .It provides a backup of 72 hours and charging time is 72 hours.

Power Distribution Board: The Power Distribution Board receives a specified power supply at the power

supply input terminals ,and the outputs it through a noise filter to the power supply output connector(CN1
and CN2).To turn off the power to the cards ,disconnect the power supply output connectors on the power
distribution board.

Node Units: Are the signal processing units which convert and transmit analog or digital process I/O signal
received from the field devices to the FCU for FIO .In order to connect node to I/O modules of FCU
ESB(Extended Serial Backboard) Bus coupler can be used.
6.Conclusion
The experience of my vocational training at the Aditya Birla Chemicals (India) Limited has been immensely
informative and helping. I have learned many new technical subjects, acquired a no. of new technical skills
and improved the existing ones too other than those gained at the university laboratories. What I liked most
about my training is that it is very strongly related to academic materials and laboratories we studied in the
university. However, I had learnt a great amount of new things too which is surely going to turn out
beneficial. I am immensely satisfied by the guidance and cooperation I received from all people working in
the plant. They enlightened me with all the technical knowledge they could possibly teach and the plant
visits have been tremendously informative. To summarise with, the main technical skills that I learned here
are as follows:
 The complete process of the production of the caustic soda and phosphoric acid and the criticality of
the processes
 Various instruments used in each process as per the requirement
 The calibration methods of the instruments
 The working and connection details of the DCS system
 The tagging procedure of the instruments.
 Develop communication and management skills.
 Learnt how to approach the problem and solve it in a plant where simultaneous activities will be
going on.
 I was given to analyse the problem and give solution which was positively considered and corrected.

In the end, I would like to state that the 4 week internship training has been a really enlightening and I am
grateful to all for helping me to complete my training successfully.
7.Bibliography
 https://www.grasim.com
 https://www.adityabirla.com/grasim
 https://www.instrumentationtoolbox.com