Automatic heating and mixing process of two materials (S7-300 FBD).
This is PLC Program for automatic heating and mixing process
of two materials.
Problem Description
Two material are collected in a tank and
mixed till it achieves set temperature. Make ladder diagram logic for this
automatic process.
Problem Solution
This logic can be implemented using a simple PLC ladder diagram.
System Description:
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Level Detection:
Use two separate level switches to detect the level of two different materials (Material 1 and Material 2) inside the mixing tank.
Additionally, one empty level switch is used to detect when the tank is empty. -
Filling Mechanism:
A single-acting valve (either fully open or fully closed) is used to control the inflow of materials into the tank. -
Mixing Mechanism:
A mixer is installed inside the tank, connected to a motor shaft, to ensure proper mixing of the materials. -
Heating Mechanism:
A heater and a temperature sensor are installed to monitor and control the temperature of the mixture.
Control Logic Overview:
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When the tank is empty (as detected by the empty level switch), open the valve to start filling Material 1 and Material 2 based on their respective level switches.
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Once both materials reach their required levels, close the inlet valve.
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Start the mixer motor to begin mixing the materials.
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Simultaneously, turn on the heater and monitor the temperature using the temperature sensor.
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Continue mixing and heating until the mixture reaches the desired set temperature.
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Once the temperature is reached:
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Stop the mixer and heater.
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Open the discharge valve (Q0.4) to empty the tank.
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After the tank is emptied, the process can restart based on the empty level switch detection.
Program
Here is PLC program for automatic heating
and mixing process of two materials.
List of Inputs/Outputs
Inputs
List:-
Cycle
START button:-I0.0
Cycle
STOP button:-I0.1
Level
of material 2:-I0.2
Level
of material 1:-I0.3
Empty
level SW:-I0.4
Temp
sensor:-I0.5
Outputs
List:-
Material 1 valve:-Q0.0
Material 2 valve:-Q0.1
Agitator motor:-Q0.2
Heater:-Q0.3
Discharge valve:-Q0.4
M Memory:-
M0.0=Master
coil.
FBD diagram for automatic heating and mixing process of two materials.
Program Description
This example illustrates a simple control process divided into five logical networks. The process demonstrates a basic sequence for material filling, mixing, and discharge, using input/output devices. This application is intended for educational and learning purposes only.
🔹 Network 1: Cycle Start/Stop Control (Latching Circuit)
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A latching circuit is used to control the cycle operation.
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The cycle starts when the Cycle START push button (I0.0) is pressed.
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The cycle stops when the Cycle STOP push button (I0.1) is pressed.
🔹 Network 2: Material 1 Valve Control
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The Material 1 valve (Q0.0) is turned ON under either of the following conditions:
The Cycle START button (I0.0) is pressed.
The Empty Level Switch (I0.4) is activated.
🔹 Network 3: Material 2 Valve Control
-
When the level of Material 1 is detected (I0.3), the Material 2 valve (Q0.1) is turned ON to begin the second stage of filling.
🔹 Network 4: Heater and Agitator Motor Control
-
Once the level of the combined materials is detected by Level Sensor (I0.5):
The Agitator Motor (Q0.2) is also turned ON to begin the mixing process.
The Heater (Q0.3) is turned ON.
🔹 Network 5: Discharge Valve Control
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When the Temperature Sensor (I0.5) indicates the required condition is met, the Discharge Valve (Q0.4) is turned ON to release the processed material.
⚠️ Disclaimer
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This application is designed only for educational and demonstration purposes. It may differ from real-world applications in functionality and safety requirements.
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All parameters and graphical representations used in this example are illustrative only and may vary in practical scenarios.
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Critical interlocks and safety measures are not included in this simplified example.
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Users must ensure proper implementation, installation, and maintenance, and are fully responsible for the safe operation of any PLC system derived from this concept.
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Always follow safety standards and consult appropriate guidelines during actual deployment.