Implementing an agitator with a soft starter controlled by a new HMI

Abstract: When an agitator is in commission for an extended period of time the impellers can become clogged. In order to clean the impeller, the agitator is runned backwards. This is one of the main functions for a product that CG Drives & Automation is developing for a customer in the agitator business. The purpose of this bachelor thesis is to develop and test this product for CG Drives & Automation. The product is an automated smart agitator control system. The heart of the product is a B&R PLC that is connected to a soft starter, a panel that runs a HMI as well as various digital outputs for external alarms and actions. By using a soft starter, the mechanical stress in starts and stops will be reduced. The soft starter is built and manufactured by CG Drives & Automation. The HMI is presented through a touchscreen panel where an operator can get a good overview of the process and, if necessary, manually run cleaning sequences or acknowledge alarms. The components are built into a cabinet by Rittal which is installed on site near the agitator. These functionalities, with minimized mechanical stress, improved safety features along with alarms, will lead to a decrease in maintenance as well as an increase in uptime. And long term, the advantages will lead to revenues for companies using this product. The soft starter is connected to the PLC both through hard wires (IOs) and Modbus TCP/IP. The hard wiring is used for crucial commands that are not allowed to fail, such as start and stop. Modbus handles the communication of other data and functions, such as the current and power percentage that is displayed on the screen. The PLC code and HMI were made in B&Rs Automation Studio software. The languages used for the PLC code were ladder, function block, and structured text. Despite the numerous amounts of technical difficulties that arose during the project, it was completed on time and according to the specification. However, the setup has not been tested in the correct environment because a suitable agitator was not accessible. A smaller electrical motor was used as a substitute for the real agitator.