Feature: Boosting canning line efficiency

The best canning line SCADA system in the world? Probably. Doug Woodbridge of Dickinson Control Systems looks at the implementation of SCADA at Carlsberg Tetley's Northampton plant

The ultimate measure by which efficiency is measured within the brewing industry is the cost per barrel. This is determined by the efficiency, effectiveness and flexibility of the packaging department, as it is through the means of kegging, canning and bottling that the product ultimately is delivered to the consumer.

But how can you achieve significant improvements in this area? Clearly, newer and faster packing technology provides one part of the solution, but for Carlsberg Tetley Northampton's Packaging Team, on-line access to the right information is the ultimate key.

Carlsberg Tetley decided to overhaul and modernise all aspects of the Northampton site packaging department and chose Dickinson Control Systems as its systems integration partner to help select and implement a site standard SCADA/MIS system.

Packaging manager Mick McKeown explains: "We needed a partner fully capable of helping us through this task: Dickinson's proactive approach made them the ideal candidate."

The first decision that had to be taken was selection of the SCADA package that was to be used as the basis of the new system. Decisions of this kind are never easy, but in this case the latest version of Siemens WinCC SCADA was chosen, according to packaging manager Mick McKeown, largely owing to the perceived all-round flexibility and technical competence of the package. Unlike most, it features an in-built relational database at its core, allowing complex queries to be performed directly on the SCADA data. Additionally, large quantities of Siemens equipment were employed already on-site and were fully supported by the package. To achieve a common look and feel across all systems, site standards were then jointly developed by Carlsberg Tetley and Dickinson Control Systems, setting out guidelines for all future SCADA and HMI configuration.

The first Northampton packaging SCADA/MIS project to be engineered using WinCC was for the new high speed (1400 can/minute) canning line supplied by Elson Projects. In order for this implementation to succeed, the Carlsberg Tetley Packaging Team concentrated on the operational perspective, working closely with Elson on the custom packing line engineering perspective, while Dickinson worked on integration, and Siemens provided technical product support as required.

In simple terms the outline design brief for the canning line SCADA/MIS was to provide a system capable of:

• Gathering data from machines on the canning line
• Monitoring and displaying current machine status
• Logging performance and generating production reports
• Providing a means to measure machine performance and record faults
• Querying logged data to produce custom reports.

High speed canning The high speed lager canning process at Carlsberg Tetley Northampton follows a conventional pattern. Empty cans are delivered at a lorry unloading station. The cans are then taken off the pallets at a bulk can depalletiser and travel on the empty can conveyor system to the filler/seamer. Filled cans are then transported on conveyors to the pasteuriser. The cans are finally checked at fine level inspection, where under filled cans are rejected. There are then two packaging lanes where can packs are made up and placed in trays and shrink wrapped, following which the packs are conveyed to the transfer table and on to the palletiser for despatch.

In total there are 19 Siemens PLCs controlling the individual machines comprising the canning line. The machines are from various manufacturers, the line having been custom designed by Elson utilising equipment components from the appropriate best-of-breed machine vendors. This in itself posed a major co-ordination challenge, both in obtaining the necessary detail and developing the necessary interface to each machine vendor's PLC. This problem was solved using a dedicated Siemens S7-414 Data concentrator PLC, standardising on common data exchange tables and utilising a common TCP/IP communication highway.

The system architecture designed by Dickinson Control Systems is shown in Figure 1, and comprises a dual redundant WinCC SCADA system, (with three view-nodes) interfacing with new Siemens S7 PLC subsystems via a new TCP/IP Ethernet communications backbone. High-visibility Dataliner displays provide an excellent solution for line performance data annunciation whilst operators are walking around the plant, being readable from over 25m across the huge new canning hall.

Status information The individual machine PLCs determine canning line status. This status information is collected by a 'data concentrator' PLC which in turn is read by the SCADA system. All status changes are logged to a database.

Database information is summarised each shift, the shift data each day and daily data each week.

Considerable work has gone into refining the ways in which management data can be obtained from the SCADA/MIS. Dickinson has developed advanced database query tools for interrogation of line performance statistics and operational events and alarms. Both graphical and tabular SCADA screens provide the views of the canning line and access to the on-line database. Navigating between screens and queries is achieved using menu soft buttons along the top of the screen, drop-down menus and hot spots which take the operator to the selected view. All main views are accessible by this method.

Now, all levels of staff, from operators through managers to director levels use the system. Machine availability and line utilisation (against predicted targets) are measured by the system and actually form the contractual measure for acceptance of all the new canning line machines. According to Carlsberg, the system first proved its worth assisting with and highlighting problems during the canning line commissioning process by identifying the faults that were causing the majority of downtime. Even packing machine vendors can regularly be found using the system to monitor performance of their own equipment against their contractual obligations.

These fault reporting and trending tools allow operators and managers to home in on reasons for lost production, whilst ranking relative machine performances against target criteria enables focused maintenance attention on least performing items, thereby leveraging the overall line performance. Shift-related reports and the historical archive of data complement these functions. Production reports per machine and total volumes produced can also be measured at will and are actively used to optimise throughput.

In-built maintenance tools are increasingly being used and the individual hours run of each individual machine are also recorded. INOC

• Dickinson Control Systems
  Email b111@industrialnetworking.co.uk
  
• Siemens
  Email b112@industrialnetworking.co.uk
  
• Elson Projects
  Email b113@industrialnetworking.co.uk
  

C1: Figure 1: The system architecture for the plant. A dual redundant WinCC SCADA system interfaces with Siemens S7 PLC subsystems via a new TCP/IP Ethernet communications backbone