Vaibhav Dhok, Dhiraj Baurasi ,Vaibhav Gudadhe,Suraj Bawne
Department of Electronics and Telecommunication
Jhulelal Institute of Technology, Nagpur, India
E-mail:-dhok.vaibhav007@gmail.com
Contact no:- 8551954690
ABSTRACT
Nowadays, the application of PLC is widely known and used in this digital world. PLC application is obviously applied at the industrial sector. Normally, the PLC’s that have been used at the industrial field is usually used to control a mechanical movement either of the machine or heavy machine in order to create an efficient production and accurate signal processing.
INTRODUCTION
AUTOMATION is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. In the scope of industrialization , automation is a step beyond mechanization .whereas mechanization provides human operators with machinery to assist them with the muscular requirements of work, automation greatly decreases the need for human sensory and mental requirements as well. Automation plays an increasingly important role in world economy and in daily experiences.
Different tools of automation
- DCS- Distributed Control Systems
- HMI- Human Machine Interface
- Field Instruments Applications
- It is used in industries like power plants, steel plants, cement plants, water treatment plant, etc.
- It is used in elevator.
- It is used in traffic control
- It is used in domestic electronic systems like, alarm system, etc.
PLCs are used in many machines and in many industries. PLCs are designed for multiple arrangement of digital and analog inputs, outputs, extended temperature ranges and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed-up. A PLC is an example of a “hard” real-time system since output results must be produced in response to input conditions within a limited time, otherwise unintended operation will result. PLC programs are typically written in a special application on a personal computer, then downloaded by a direct-connection cable or over a network to the PLC.
Definition:A digitally operating electronic apparatus which uses a programming memory for the internal storage of instructions for implementing specific functions such as logic, sequencing, timing, counting and arithmetic to control through digital or analog modules, various types of machines or process.
AIM
Water system consists of raw water treatment. Raw water treatment plant are controlled & monitored from PLC based control system located in MCC panel room near to raw water treatment plant
Detail of PLC panel
RO SYSTEM
- Cabinet size : 1300(H) X 800 (W) X 300(D)
- Pre treatment Stream ON/ OFF indication to be provided on panel Door
UF SYSTEM
- Cabinet size : 1100(H) X 800 (W) X 300(D)
- Pre treatment Stream ON/ OFF indication to be provided on panel Door
- 24V DC indication
What is PLC?
A PROGRAMMABLE LOGIC CONTROLLER (PLC) is an industrial computer control system that continuously monitors the state of input devices and makes decisions based upon a custom program to control the state of output devices.
Almost any production line, machine function, or process can be greatly enhanced using this type of control system. However, the biggest benefit in using a PLC is the ability to change and replicate the operation or process while collecting and communicating vital information.
Another advantage of a PLC system is that it is modular. That is, you can mix and match the types of Input and Output devices to best suit your application.
PLC which we are using :
A. RO SYSTEM ON LOGIC
START LOGIC
- Select Ro start from Panel
- Flushing /Reject Valve ( Auto Valve 2)(AV02) Should be open Time Delay – 30 Second
- Ro Feed Pump Should start ( Ro feed Pump 1 Or 2) Time Delay 5 Second
- SMBS Dosing Pump (DP02)Should start. Time Delay 120 Second after Feed pump start.
- Antiscalent dosing Pump (DP01)Should Start Time Delay 5 Second
- Acid Dosing Pump (DP03) Should start Time Delay 5 Second .
- Ro High Pressure Pump Should start Time Delay 2 Minutes
- Auto Reject valve Shall Close ( Auto Valve 2 )
Piping and Instrumentation Diagram(P&ID):
- Piping and instrumentation diagram (P&ID) is a diagram in the process industry which shows the piping of the process flow together with the installed-equipment and instrumentation.
P&ID of RO Plant
- P&IDs play a significant role in the maintenance and modification of the process that it describes. It is critical to demonstrate the physical sequence of equipment and systems, as well as how these systems connect.
- A diagram which shows the interconnection of process equipment and the instrumentation used to control the process. In the process industry, a standard set of symbols is used to prepare drawings of processes.
- The instrument symbols used in these drawings are generally based on International Society of Automation(ISA).
P&ID of UF Plant
- During the design stage, the diagram also provides the basis for the development of system control schemes, allowing for further safety and operational investigations.
- In this P&ID, two pumps are shown for each dosing pumps and feed pumps. The first pump is the active pump or the pump in action, whereas the second pump stays in standby mode. If the first pump malfunctions for any reason then the second pump which is in standby mode will become active.
- This is done to ensure the continuity of the system even if any fault occurs in the system.
- To Stop the Ro cycle , Select Stop from Panel
- Auto Reject Valve ( auto Valve 2) should open Time Delay 30 Second
- Ro High Pressure Pump Should stop Time Delay 30 second
- Two Dosing Pump (Antiscllant / Acid ) Should stop Time Delay 120 Second After delay time Ro feed Pump and SMBS dosing Pump Should stop and close
Advantages:
- They are fast and designed for the rugged industrial environment.
- They are attractive on Cost-Per-Point Basis.
- These Devices are less Proprietary ( E.g.. Using Open Bus Interface.)
- These Systems are upgraded to add more Intelligence and Capabilities with dedicated PID and Ethernet Modules.
- Reduced space , energy saving, ease of maintenance ,economical ,greater life & reliability ,tremendous flexibility, shorter project time.
- Easier storage, archiving and documentation.
Applications:
- It is used in industries like power plant, steel plant, cement plant, water treatment plant, etc.
- It is used in elevator.
- It is widely used traffic control lights.
Future Scope:
- The existing drinking water treatment plant capacity will increase.
Reference:
- Watertech Services Pvt.Ltd.
- Wikipedia
