Tank Control at Klawer
In 2005, ANA-DIGI SYSTEMS and Adroit Technologies teamed up for the Klawer project to ensure Klawer remains one of the leading producers of quality wines in Cape Town.
Klawer, located in southern Namaqualand, 260 km from Cape Town, needed a reliable, easy-to-use solution for its wine tank control system, along with world-class support and backup. It was decided to use the LS GM4 PLC and LS iG5 inverters as the foundation for a flexible and dependable control system. Adroit SCADA was chosen as the preferred operator interface for its ease of use, flexibility, good graphics, and expandability. As Adroit Technologies is based in South Africa, the client was assured of ongoing service and support.
Background
In 2005, Klawer Wine Cellars had virtually no fermentation or maturation tanks. It functioned as a receiving depot for grapes from the region, but after crushing, the grape juice had to be pumped into container vessels and trucked to Trawal Wines, a sister winery 20 km away, for further processing.
The decision was made to process wine under the Klawer Wine Cellars name. A refrigerated hall was built, and an order was placed for 12 maturation tanks and 10 fermentation tanks. The expanding local wine industry required innovative solutions to handle the increasing grape yields from the Klawer area, presenting an opportunity for Klawer Wine Cellars to become a significant player in the region’s wine processing and sales.
Fermentation Tanks
The 10 main fermentation tanks are primarily used for white wine processing or temporary wine storage. Six additional fermentation tanks were later added to meet the growing needs of the plant. All fermentation tanks are equipped with temperature probes and solenoid valves to control the wine’s temperature. Cold glycol is circulated through the jacketed walls for cooling, with temperature set-points entered via the Adroit SCADA system.
Maturation Tanks
The 12 maturation tanks are mainly used for processing red wine, which requires more attention and longer processing times than white wines. These tanks are equipped with additional equipment, such as stirrers on the bottom and pumps to recirculate the wine. Sprayer nozzles at the top ensure an even distribution of recirculated wine.
The maturation tanks are also cooled by glycol pumped through the walls. Temperature probes and solenoid valves allow for temperature control, while pressure transducers at the tank’s bottom monitor the level and ensure pump low-level safety.
Critical Temperature Control
During maturation, temperature control is critical as the fermentation process generates significant heat. A cake of grape skins and husks forms at the top of the tank and can solidify if not properly managed, requiring forceful breaking up. To prevent this, the solution involves continuously stirring the wine and cyclically recirculating it. The recirculation wets the cake by spraying the wine back onto the top of the tank.
Pumps, fitted with LS frequency inverters, vary the pump speeds, ensuring uniform spray coverage of the cake. Critical parameters such as temperature set-points, pump cycle times, and variable pump speeds are managed through the Adroit SCADA system. Once configured, the system operates automatically day and night during the wine processing season.
Klawer Wine Cellars’ Growth
Klawer Wine Cellars has quickly become a leading wine producer in the region. It not only produces its own wine but also matures wine for neighboring wineries. The streamlined handling process has attracted farmers from across the area to deliver their grapes to Klawer. In some cases, farmers can choose to be paid based on grape tonnage or yield quantities after crushing. The tank level control is used to determine wine yield quantities.
Support and Expansion
Support and backup are provided by ANA-DIGI SYSTEMS of Cape Town. The system’s flexibility allows for easy expansion, with up to 32 remote stations possible. The remote GM6 PLC, required for the new fermentation tanks, is connected via an LS F-Net bus system—an LS fieldbus network that is fast, reliable, and simple to set up. The user-friendly Adroit SCADA interface allows relatively unskilled workers to operate the system. The seamless expansion of the SCADA package and version compatibility have been vital over the last four years.
The control system was recently expanded. The Adroit SCADA package was upgraded from 150 to 300 scan points, and the LS GM4 PLC was expanded to include a remote GM6 slave rack when six new fermentation tanks were added at the end of 2007.
Ongoing Collaboration
The partnership between Adroit Technologies and ANA-DIGI SYSTEMS has delivered a trusted, proven solution for many clients. The support and backup provided by Adroit Technologies are highly valued by both ANA-DIGI SYSTEMS and its clients. In the future, this combination of Adroit SCADA and LS PLC equipment will continue to provide users with peace of mind, knowing their automation needs are fully met.