DESCRIPTION

Technical Description

The supply of processes with media such as water and compressed air in industry is usually provided from a separate, centralised supply unit. Control and monitoring of the processes are also centralised from a control station. RT 590 enables familiarisation with a practical scenario of this nature.

The trainer includes a water circuit with a pump, collecting tank and graduated tank. In this circuit, the flow rate and level are controlled by way of pneumatic control valves. The level control can also be executed under counter pressure or as cascade control. An additional tank can be connected to facilitate learning with a second-order level controlled system. 

Compressed air is used in the control of pressure. The level of liquid in the tank can be varied to give time-varying response of the controlled system. 

The temperature control takes place in the collecting tank. Warm water flows into the tank. Cold water is mixed in using a control valve, thereby regulating the temperature in the tank. Three delay sections are used to set different dead times.

The separate control station includes the controllers and line recorders for monitoring and control of the control processes. The controllers have a Profibus DP interface. This enables the trainer to be controlled by using a process control software. The software also permits recording of the process variables and parameterisation of the controllers using the PC. Pushbuttons on the control station are used to simulate typical faults such as failure of sensors or cable breaks. The separate supply unit supplies compressed air and warm and cold water.

Learning Objectives / Experiments

- familiarisation with industrial process engineering plant
- flow rate control
- level control with and without counter pressure
- level control with second-order controlled system
- cascade control of level and flow rate
- pressure control with time-varying response of the controlled system
- temperature control with time-varying response of the controlled system
- fault finding