This project analyses the simulation strategic considerations of PLC based mini cement plant system by developing ladder diagrams using the addressing modes of Allen Bradley PLC. This project presents comprehensive simulations of the performance of the different electrical actuators such as stepper motor, solenoid valve etc., the position sensor and the conveyer belt. Program execution status can also be monitored by the PLC. It scans memory, inputs and outputs in a deterministic manner. The user can access the logic, counting and memory functions easily by using this adopted simulation strategy with good performance and more reliability. The design is for the production of large volume high quality dry powdered cement with PLC used as its controller, which implements ladder diagram logic to monitor the output signals from the different input sensors.

1. MINI CEMENT PLANT USING PLC
Alik Saha*, Sushil kundu*, Apurba Ghosh**
* B.E. Final year student, ** Reader / Assistant Professor
Department of Applied Electronics & Instrumentation Engineering,
University Institute of Technology, Burdwan University, Burdwan – 713 104, W.B., India.
Email: alik.saha4001@gmail.com
sushilkundu143@gmail.com
apurbaghosh123@yahoo.com
Abstract- This paper analyses the simulation study of PLC based mini cement plant system by
developing ladder diagrams using the addressing modes of Allen Bradley PLC. This paper presents
comprehensive simulations of the performance of the different electrical actuators such as stepper motor,
solenoid valve etc., the position sensor and the conveyer belt. Program execution status can also be
monitored by the PLC. It scans memory, inputs and outputs in a deterministic manner. The user can
access the logic, counting and memory functions easily by using this adopted simulation strategy with
good performance and more reliability.
Keywords- Ladder diagram, stepper Motor, conveyer belt, position sensor, solenoid valve, PLC
I. Introduction
Industrial automation is the use of control systems to control industrial machinery and processes, reducing the
need for human intervention. If we compare a job being done by human and by automation, the physical part of
the job is replaced by use of a machine, whereas the mental capabilities of the human are replaced with the
automation. PLC [1 – 5] is the abbreviated form of Programmable Logic Controller. Historically a PLC forte
was in discrete control of manufacturing processes. Most of the inputs and outputs for discrete control are
binary, meaning they have only two states i.e. on and off, like a switch. Little processing power is needed for
computing on/off signals and hence PLC tended to be very fast and are used in machine tool and other
industries. PLCs started becoming popular in the 1970s they were often called "relay replacers", since the logic
for on/off type operations was done with relays arranged in a digital logic format. Manufacturers of the most
popular PLCs include Allen-Bradley, Siemens, Modicon and a bunch of others. The design is for the production
of large volume high quality dry powdered cement with PLC used as its controller, which implements ladder
diagram logic to monitor the output signals from the different input sensors[4].
Fig. 1 Block diagram of mini cement plant.

2. II. System description
The gypsum and clinker are fed in a subsequent manner depending on the time adjusted on the timer into a
dump hoper and then it is collected into a crusher as shown in the Fig. 1. After crushing for some time, the
material is sent to bucket elevator-2 used for clinker via conveyer belt-2 using the motor-2. When gypsum is
crushing over, it is fed to bucket elevator-1 through conveyer belt-2 and conveyer belt-1 with the help of both
the motors M-2 and M-3. Further the crushed products of clinker is again sent to the bucket elevator-3 using the
conveyer belts 1 and 2 with the help of motors M-2 and M-4. The crushed gypsum is stored in the tank(GYP)
using motor, M-5. The crushed clinker is deposited in the tanks , CLH-1, CLH-2, CLH-3 and CLH-4 by running
the motors M-6 and M-7. Then the gypsum and the clinker from the respective storage tanks are fed to the
millfed bucket elevator operating the motors, M-8, M-9, M-10, M-11, M-12 and M-13. The materials are then
sent to the cement mill using motor, M-14. Once the production of cement [6] is complete, the finished product
is transferred using bucket elevators, motors (M-15& M-16) and solenoid valve(V-1) to large storage silos
(SILO-1 & SILO-2) in the shipping department. The final product is then transferred for packing and loading
using the motors, M-17, M-18, M-19, M-20, M-21 and M-22.
III. Explanation of ladder diagram
The logic implemented in PLCs is based on the three basic logic functions (AND, OR, NOT). These functions
are used either singly or in combinations to form instructions that will determine if a device is to be switched
ON or OFF.
The complete ladder diagram can be thought of as being formed by individual circuits, each circuit having
one output. Each of these circuits is known as a rung. Therefore, a rung [3] is the contact symbology required
to control an output in the PLC. A complete PLC ladder diagram program [2] then consists of several rungs,
each controlling an output interface which is connected to an output field device.
Here sensor (I:1/0) is implemented as start switch normally open (NO). If I:1/0 gets high value then the
motor-1(M1) of crusher starts crushing for some time which is run by timer T4:0 as shown in Fig. 2. Motor2(M2), motor-3(M3), motor-4(M4) are made on by using timer T4:0, T4:1 and T4:2 respectively having
addresses of O:2/1,O:2/2,O:2/3 respectively. The output address of O:2/4, O:2/5 and O:2/6 are used for
running of motor-5(M5), motor-6(M6) and motor-7(M7) respectively with the help of timer T4:3. Then the
motors, M8, M9, M10, M11, M12, and M13 are connected in the different addresses with the help of timer
T4:4. When T4:5/TT goes high then the motor -14(M14) connected in the address of O:2/13 will start. The
motor-15(M15) would be running when T4:6/TT goes high. The solenoid valve(valve-1) of cement mill is made
on when T4:7/TT high and T4:8/DN low. If T4:8/TT gets high then the M16 starts operating. M17 and M18
are on when T4:9/TT gets high. When T4:9/DN, I:1/4 or O:4/3 are high and C5:0/DN (here C5:0 is
implemented as counter) , T4:10/DN are low then the motor-19(M19) connected in the address of O:4/3 and the
motor-21(M21) connected in the address of O:4/4 are on. If T4:9/DN high, I:1/5 or O:4/5 high, C5:1/DN
low,T4:10/DN low are connected in cascade then the M20 and M22 runs. Here the NO switch (I:1/1) is used for
the system stop. Once system stop gets high then overall system will shutdown.

4. Fig. 2 Ladder diagram.
IV. Conclusion
This Paper has discussed an application of PLC for the mini cement plant system. The results of simulation
study were presented as far as the steps of process progress. All of our personal sketches and drawings of the
setup and prospected design of the mini cement plant were saved for reference for the actual design process. A
simple decision logic scheme on receiving the input signals was used to process the outputs of the mini cement
plant system to indicate the status of the process.
The study also indicates the condition of the motor of the conveyer belt and the status of the solenoid valve.
Further work is requested to indicate the use of on-line parameter identification to improve the performance of
the decision logic.
Hence, it can be concluded that the system designed and developed set up works satisfactorily and can be used
for demonstrating an application of PLC.
V. References
[1] Gray Dunning, Introduction to Programmable Logic Controllers, Delmar Thomson Learning, 1998.
[2] Programmable Logic Control : Principles & Applications, NIIT, PHI, 2004.
[3] John W. Webb, Ronald A. Reis, Programmable Logic Controllers, principles & Applications, 5th Edition, PHI; 2003.
[4] Madhuchanda Mitra, Samarjit Sen Gupta, Programmable logic controllers & industrial automation.
[5] L.A. Bryan,E.A. Bryan, Programmable Controllers Theory and Implementation, Second Edition, 1997.
[6] J. P. Saxena, Refractory Engineering and Kiln Maintenance in Cement Plants, 2003