PRESENTED BY
V.Prudhvikumar
V.Trivendra
V.Veerabhadra Rao
G.Phanidhar

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ABSTRACT
The main aim of this project is to design a system for oxygen enrichment in the cold blast airlines of a Blast Furnace at Visakhapatnam steel plant using a Programmable Logical Controller (PLC).
The rate of oxygen injection is controlled from the PLC based on the set oxygen percentage at the blast furnace control room, through the Flow Control Valve.
Percentage of oxygen shall be set manually; rate of oxygen flow to the flow of cold blast will get adjusted automatically.
This enrichment system is provided to increase the rate of production. The maximum injection capacity is 1.9%.
OXYGEN ENRICHMENT SYSTEM
System Architecture
System Description
Control System Description
PLC software structure
OVERVIEW OF OXYGEN ENRICHMENT
PROCESS PARAMETERS
The system design is based on the following process parameters
Oxygen inlet pressure at PRS 20-38Kg/cm2
Oxygen outlet pressure at PRS 5-6Kg/cm2
Inlet flow of Oxygen in each stream 3000-7000Nm3/min
Flow of cold blast air in each stream 4000-5700Nm3/min
Pressure of cold blast air 2.5-3.7Kg/cm2
Moisture in cold blast air 60gm/m3
INSTRUMENTATION INVOLVED
ACTUATORS USED:
Pneumatic actuator
Electrical actuator
CONTROLLERS USED:
PID controllers
Programmable Logic Controllers
BF CONTROL ROOM
The rate of oxygen into cold blast can be arrived from the following formula.  0.785 x O2 FLOW  Y = ________________ X 100 COLD BLAST FLOW Where Y = % oxygen enrichment. 
Introduction to PLC
A Programmable Logic Controller is a digitally operated device that uses a programmable memory for intermediate storage of instructions that implements specific functions such as:
Logical
Sequential
Timing
Counting
Arithmetic
functions to control machines and processes.
BLOCK DIAGRAM OF PLC
PROGRAMMABLE LOGIC CONTROLLER
PLC PROGRAMMING
PLC programming is done by Versapro software.
The basic notations used in programming are:
1. Digital input: %IXXXX
2. Digital output: %QXXXX
3. Analog input: %AIXXX
4. Analog output: %AQXXXX
5. Registers: %RXXXX
6. Flags: %MXXXX
7. Temporary bits: %TXXXX
8. System bits: %SXXXX
9. Global bits: %GXXX
LADDER PROGRAMMING
Ladder program is one of the methods of programming the PLC’s. the flow of the program is “Left to right top to bottom”
Basic ladder logic symbols are:
Contacts: Normally open -| |-
Normally close -|/|
Boxes:
Coils: -( )-
SAMPLE LADDER PROGRAM
Advantages
Reduced space when compared to hardwired controller.
Energy saving compared to relay logic control.
Easy maintenance.
Economical.
Greater life and reliability.
Tremendous flexibility.
Easier storage and documentation.
Short project time.
CAPABILITIES
Logic control.
PID control.
Coordination and communication
Operator control.
ONLINE and OFFLINE programming is possible.
High processing speed.
APPLICATIONS OF PLC
• Manufacturing Industry - Lead acid battery plant, complete manufacturing system. - Extruder factory, silo feeding control system • Travel Industry - Escalator operation, monitored safety control system. - Lift operation, monitored safety control system. • Aerospace - Water tank quenching system • Printing Industry - Offset web press print register control system. - Multi stage screen washing system. . 

• Hospitals - Coal fired boiler fan change-over system. • Film Industry - Servo axis controlled camera positioning system. • Agriculture - Glasshouse heating, ventilation & watering system. • Foundry - Overhead transportation system from casting process to shot blasting machine. • Leisure - Roller coaster ride and effects control system. - Greyhound track 'Rabbit' drive system
CONCLUSION
By the implementation of this system, the production rate is increases.
The operation and maintenance is made easy by using this system. Now the system will work effectively without any complications.