Branston has been suppling high quality potatoes since 1968. The company has sites in Lincoln, Scotland and Seavington near Ilminster and it is here that a new method of water treatment has produced both operational savings and enhanced environmental credentials. The project was undertaken by MSE Systems in conjunction with InControl Systems using manufacturing automation software products from Wonderware, provided by SolutionsPT
On the face of it cleaning and packaging potatoes for retail sale is a simple operation. However, water usage has significant economic and environmental issues. In today’s markets all aspects of processing are placed under scrutiny and Branston knew that its water usage needed to be improved, not only for its own benefit but to meet the stringent requirements of supplying a major retailer.
Water in large volumes is needed to process the potatoes and this was causing significant cost and environmental concerns to Branston. The company has a borehole on site, with water abstraction undertaken with a regulated licence from the Environmental agency. Mains water is also available to the site but with some supply restrictions. Branston needed a safe method to recycle the water rather than continuously drawing water and contacted MSE Systems for a solution.
Membrane BioReactor
MSE Systems supplied a complete water treatment plant, called a Membrane BioReactor (MBR), which has met the customer’s requirements. MBRs combine activated sludge treatment with a membrane liquid-solid separation process. The membrane component uses low pressure microfiltration and eliminates the need for conventional clarification techniques and tertiary filtration.
The process of recycling the washing water is complex as the water has to be purged of both the inevitable soil content and the nitrogen and phosphorus from fertilisers and organic contamination. Other aspects of repeated water use such as chemical build up were anticipated and these were dealt with through granulated activated carbon absorption. The filtering and treatment process includes solids separation, aeration, carbonaceous oxidation and nitrification, final membrane filtering, granulated activated carbon absorption, ultra-violet treatment and chilling to 10°C for reuse. Branston has laboratory equipment to monitor the system and to analyse the water which confirms environmental compliance and provides data to operate the plant. This equipment is located at Branston’s South West site where the analysis for this site and the Lincoln site is carried out. Up to 90 per cent of water at the South West site is now recycled, with any waste being safe to return to the public system.
Visualisation and automation
The control and automation of the plant was undertaken by InControl Systems using Wonderware technology. At the Seavington site this uses Wonderware InTouch SCADA and data collection, with PLC control using a Rockwell CompactLogix. The automation system has 25 closed loops and 50 analogue monitoring points. The InTouch SCADA which visualises the entire system was used in plant tuning as well as continuous monitoring of plant operation. However, this system was already applied at the Lincoln site so the South West site was integrated to the county-wide automation architecture which uses a centralised system (located at InControl Systems) and thereby keeps the IT infrastructure requirement at ‘client sites’ to a minimum.
Integrated information service
MSE Systems knew that its MBR water treatment installations would require monitoring for optimum performance and in particular to ensure that the membrane filter system was running to specification. This requirement, as well as numerous other monitoring and remote access requirements, was integrated by InControl Systems to produce the ‘MyMSE’ Server Architecture. MyMSE is based on Wonderware System Platform technology which has allowed master objects to be developed for such applications. In use these well developed and tested objects are simply deployed repeatedly to produce the particular application. This has the effect of reducing project development and commissioning time thanks to thorough master object development and subsequent use of multiple instances of each object. PLC programming is also pre-specified by each master object, bringing standards to bear at the PLC level and allowing PLC control and Supervision to become tightly integrated.
Access control is managed by Microsoft Active Directory. Detailed trend displays are available to all users, centrally, at client site, and remotely via ‘zero-touch’ web browsers. The trends offer in depth insights into the process and have been of particular use both in process tuning and in on-going monitoring.
Geo-SCADA
The use of Wonderware System Platform creates a library of tested master template objects which are held centrally within the ‘System Platform Galaxy Repository’. Instances of these templates are deployed to each site as required. Additional clients and their site deployment are thus readily facilitated. This also helps with ‘Continuous Improvement ‘as master template objects can be updated and the resultant changes deployed remotely.
A further development of the core central system will allow extended Geo-SCADA functionality. This will display each client site on a map with an instant indication of status and of any alarms. This feature will ensure that any problems are dealt with immediately. MSE and InControl will also be able to respond to any client site plant and control problem by instantly being aware of an issue and also by periodically monitoring particular aspects of the plant from a long term view of availability.
Jan Hemper, InControl Systems says: “Wonderware System Platform was the ideal solution for this geographically spread project owing to its functionality and also to its efficiency in application development engineering.”
Customer benefit
Branston’s general manager at the South West site, Ian Wait, says: “The system provided by MSE and the information technology from InControl takes care of management expectations for the water treatment plant.” Wait adds that he has web access to the system at any time and from any location. Remote access information has been augmented by the use of advanced diagnostics developed by InControl which utilises Wonderware Information Server ‘Web Parts’ in conjunction with Microsoft SharePoint. This allows authorised users to automatically obtain their required selection of reports by email.
The system also records use of the site’s borehole water abstraction and produces reports and readings that are used to ensure that the site is within Branston’s Environmental Agency licence. Furthermore a complete overview of water inputs and outputs to the site, which is measured by flow meters, is automatically maintained in the site’s history and corresponding trend displays.
