UCS Automation will design, assemble and test a complete control system solution for the above project.
The control system will consist of a floor standing IP55 control panel suite, to contain all control gear for 7-off Chamber Dryers. The control panel suite will consist of a Distribution section, a MCC section and a PLC section. The suite will be fully bayed c/w a divider panel separating the PLC section from the 3phase MCC section. The PLC section will be fitted with a touch screen HMI and door-mount Ethernet port to allow connection to the PLC.
Each Dryer will comprise of the following control elements:
Additionally common to all Dryers will be the following control elements:
The new Dryer system PLC will be connected to the Kiln PLC via the existing Profibus network, with the connection being made at the nearest possible point to the dryers, likely to be in the control room where the ‘Don Controls’ panel is located. This will provide the communication connection required to enable UCS to modify the existing WinCC Scada system to monitor the new Dryer control system PLC. Currently the Dryer control system is very fragmented comprising of various distribution board supplies located on the Roof of Dryer no.7 and the ‘Don Controls’ panel located at a lower level in the Control Room. The intention is to completely de-commission the existing collection of panels, with the exception of the Door panels and the Comtherm Burner panels, replacing them with a new single control panel suite, to be located between Dryers 4 & 5. The new system will be equipped with 8 safety circuits, one per Dryer and an overall Emergency stop system. The individual Dryer safety circuits will monitor the safety door limit switches, to be fitted to detect that the Dryer door is fully lowered. If this circuit is broken, the Burner, Dalek movement and all fans associated with the Dryer are disabled. The Emergency stop circuit is used to disable this equipment on all 7 Dryers.
Each Dryer will be capable of controlling 2 separate 16 Segment profiles, Temperature and Volume, with Humidity purely being monitored. The Waste Heat damper control will be triggered on an event during the cycle. When selected, if sufficient Waste heat is available, the Waste heat damper will take priority over the Burner control. If there is enough Waste heat to satisfy the Dryer requirements the Burner will disable, however if the Waste heat damper cannot satisfy the Dryer’s requirements when fully open, the Dryer Burner will be used to provide the supplementary heat. Each Dryer will be equipped with an independent Overtemperature instrument, such that in the event of an Overtemperature condition, the associated Burner will be disabled and an alarm will be raised.
The operator will have the facility to select a Dryer setpoint Temperature and Ramp rate for each segment of the Temperature profile. For the Volume control the operator will enter the Recirculation fan speed setpoint as a ‘%’ for each segment of the profile.
Profiles can be saved as a ‘Recipe’ and will be stored in the PLC logic, allowing them to be accessed via the panel mount HMI or the Tunnel Kiln Scada system. The panel mount HMI will also provide the operator with the facility to monitor all the Dryer plant status, via animated mimic’s, together with alarm handling and trending of all Dryer Waste heat duct temperature, Dryer temperatures, Dryer Humidity’s and Waste heat duct pressures. At Engineering level the operator will have the facility to enter PID settings, alarm deviation setting etc.
The existing Siemens Winn CC Kiln Scada system will be modified to include all the additional Dryer screens as provided on the HMI. The exact screen formats will be agreed prior to commencement of the project. Please see supplementary information showing example screen designs from previously installed 5 Dryer systems with full humidity control.
What was developed?
UCS developed a bespoke automated control system for use in the brick drying process. The aim was to dramatically improve the efficiency of the system and the quality of the product.
What previously existed in this field?
Outdated instrument control, with inefficient gas control.
What are the advance / appreciable improvement?
Lower manufacturing costs & a simplified operator interface. More efficient heating, with reduced emissions.
What were the technological uncertainties?
The implementation of a bespoke high accuracy Temperature, Pressure and Humidity profiling software to provide control loop setpoints working to the required tolerances.