Heavy Clay – Ibstock, Birtley – 2013

Dryer Control System Upgrade

The Project

Ibstock, a leading brick manufacturer in the UK, tasked UCS with providing an upgrade for a dryer control system for the existing seven brick drying chambers on site.

The existing power and control systems installed were very fragmented, power supplies were in hard-to-reach areas, making isolation difficult and the control systems were mostly outdated instruments with the only system monitor away in the control room across the factory.

This project required UCS Automation to have a good understanding of the requirements of the brick drying process, and methods to achieve the correct drying results. We also had to understand the reuse of waste heat within the drying system and burner control method. It also required an integration of some of the existing system into the new control build, such as the door panels Comtherm burner panels, Siemens WinCC SCADA. The requirements found on survey as detailed below in Understanding the Process.

Surveying the Project:

The main concern with this project was whether a temperature, pressure and humidity profiling software could be implemented to provide the needed setpoints, whilst keeping the drying chambers within required tolerances. There was also a concern regarding compatibility of existing equipment and the new controller

To future-proof the project, it was decided that the existing power and control systems would be removed and relocated to a single IP55 rated enclosure on floor level between the dryer chambers. This would give better access for maintenance and easy isolation when required, whilst protecting the equipment from environmental factors.

The existing SCADA system in the control centre was also modified to incorporate the new screens available on the dyer HMI, allowing visibility across the factory.

In 2013, UCS Automation delivered, installed and commissioned the dryer control system upgrade. The result was an overall increase in the dryer’s overall equipment effectiveness and operating efficiency. The new profiler system allowed maximised use of waste heat, using less gas to operate whilst maintaining the humidity of the kiln to decrease drying defect. The concerns we had with the project at the start were overcome by working with the client throughout the project resulting in a successful implementation.

Our Services

We provided the following services for this project:

• Electrical AutoCAD design drawings. See our Design page
• Control Panel Manufacturer. See our Manufacture page
• PLC & HMI Software design. See our Software Design page
• SCADA Modification
• Disconnection and removal of the existing mechanical system
• Installation, Testing and Commissioning of the system. See our Installation and Commissioning pages

Control System:

Control of the entire system was handled by Siemens S7-300 line of PLCs. A S7 315-2DP PLC, MP277 HMI and ABB ACS550 inverters were utilised on this project. The interconnections were a mixture of Profibus communications and direct wired control.

The MP277 HMI was a 10.4” colour screen, allowing the operator to monitor the machine status and adjust the profiler settings, storing and loading as recipes, making product changes much quicker.

Understanding the Process:

As part of the process UCS Automation needed to learn and fully understand the operation of the dryer process. The plant was grouped into several, smaller functions, for the development process.

A) Existing SCADA & Kiln PLC

The existing SCADA was a Siemens WinCC machine with communication via a Profibus network. Existing controls were hardwired, and very little monitoring was available from the SCADA. The Kiln PLC was also a Siemens system, so PLC communications was straightforward

B) Power Supply & Distribution Panels

Existing power supply very fragmented, no common connections available. Power supply was rerouted, and all existing distribution points removed, replaced with IP55 panel at floor level.

C) Safety Circuits

Safety system were added to the existing process, eight circuits in total, one for each of the seven dryers and an overseer for the emergency stop system. These detect the door closures for each dryer and prevent starting of burner ignition and fans on specific dryer in case of open door or safety failure. PLC monitored each safety and reported faults back to the HMI and SCADA. E-Stop shuts down all dryers simultaneously.

D)  Profiler

Each dryer uses two 16-segment profiles, one for temperature and one for air volume. Operators can tune each profiler per dryer as required and store settings as a recipe, to be saved/loaded when required. Ramp times for the profile are also able to be set by the operator The PLC will monitor the Waste heat pressure and establishes if it can be used to maintain the profiler setpoints, if able it feeds the dryer with the waste heat, if not the burners are enabled to reach the target setpoint.

E) PID Settings

Operators can adjust the PID loop settings to tune the profiler response. This is locked to Engineer mode, as changes are very infrequent.

F) Overtemperature

Each dryer has an overtemperature instrument, independent of the PLC system. When this is triggered, the burner locks out and the PLC is notified of a fault.