Manufacturing drinking water is a process with different steps. The last step is called disinfection, used to destroy microorganisms in water. To achieve it, systems inject chlorine. This technique is called dosing. Dosing is the technique for controlling the addition of a substance to a flowing liquid or gas. Dosing systems are designed to achieve the required dosing level by maintaining the control signal as a proportion of the fluid flow rate. In this post we are going to develop a chloride dosing system based on Arduino.
Dosing control equipment consists basically of the following elements:
- A controller, in this case we will use an M-Duino PLC.
- A flowmeter.
- A dosing pump.
- A dosing level sensor.
The following figure shows the general arrangement of the dosing control system: The dosing concentration measured by the dosing level sensor is used to stop the pump if a there is high concentration in the tank. The flowmeter provides the input of the control loop, which is connected to the pump (as the output).
Software and code
In this example, dosing level and flowmeter are configured as a 0-10V analog input. The pump works with a frequency driver. As we have to develop a control loop, we have created a PID controller linked to the specified input, output and setpoint. You can find the code to be uploaded here:Key Benefits
The main benefits of the Opiron – Industrial shields proposed solution are:
- Flexibility: This application note describes how the Open source based hardware can be used to control the dosing level of a chlorine system. However this same architecture can be used with any liquid or gas using the PID algorithm.
- Freedom to modify your software: You aren’t limited to what one company believes you need.
- Easy to be integrated: No matter if you already have an automation system. The Arduino hardware is easy to integrate into your system..
Do you have a process to be automated? Contact Industrialshields to implement the entire solution and to buy the proper hardware.