DA Radial Blower Control System

The DA blowers are provided with microprocessor-based control systems. For example, if there are four blowers installed in one plant, three blowers are equipped with SLAVE control systems designed to provide the following functionality:

protect the blower against:

• low oil pressure below a permissible level;
• high oil temperature above a permissible level;
• impeller shaft bearings overheating above a permissible level;;
• excessive relative vibrations of the impeller shaft;
• exceeding the maximum pressure for the specific position of controls;
• low oil level below a permissible value

control the blower's operation:

• prepare the blower for operation (keep the blower ready for a quick start);
• start and stop the blower, either upon the command from the MASTER system or locally by using the START/STOP buttons on the SLAVE control cabinet panel;
• alter the capacity, either upon the command from the MASTER system or locally by using the buttons on the SLAVE control cabinet panel;
• control the bleed valve on the pressure pipeline.

monitor the following variables:

• oil pressure downstream of the slide bearings;
• oil temperature upstream of the bearings;
• impeller shaft bearings temperature;
• impeller shaft relative vibrations;
• control valve positions;
• compressed air pressure;
• active electric load.

The fourth blower is provided with the MASTER control system which provides the normal SLAVE functionality for the blower it is installed on, and additionally manages the operation of the other three blowers by:

• controlling the capacity of the blower plant;
• controlling air distribution to each active sedimentation chamber via the distribution dampers on the pressure pipeline;
• balancing the power consumption;
• balancing the volume of air being forced through;
• protecting against starting all blowers simultaneously;
• displaying alarm messages and warning messages;
• performing other functions programmed on customer request.

The MASTER/SLAVE controllers are interconnected via a local bus. The MASTER controller can be interfaced to the main plant control system e.g. to the control system of a sewage treatment plant .