A new cask racking plant at the St Austell brewery can produce 300 firkins, that is 9 gallon casks, per hour. The increased efficiency allows the brewery to switch from two-shift to one-shift operation and still have double the capacity. The plant uses drives and automation equipment throughout, ranging from controllers to efficient geared motors. The networking of the system is the key to the efficient operation of the plant.
>The brewery was a turnkey installation supplied by Microdat, a UK leader for brewery keg and cask handling systems. The racking plant is a production line that takes in empty casks, cleans and fills them and then prepares them for despatch. Incoming casks will have been returned from pubs. They are fed in to a process called deshiving where the old plugs are removed, then the casks are washed and dried. The filling process, known as racking, uses accurate Microdat peristaltic pumps driven by geared motors. The full casks are then sealed and transported ready for despatch. Microdat also supplied a CIP (clean in place) system which can automatically clean the pipes and tanks with hot detergents. The level of automation is such that only three operators are required to achieve a production level of 2700 gallons per hour. This is equivalent to more than the capacity of an Olympic sized swimming pool every month.
>Lenze drives and automation systems are used throughout the plant. The heart of the automation system is a network of five Lenze 3200C controllers that are linked by Ethernet. One controller looks after each stage of the process, handling PLC logic to IEC61131-3 languages, motion control for the geared motors plus a link for external visualisation. Plugged into the side of the 3200C controller are Lenze System 100 I/O modules, with fast data transfer achieved through an integrated backplane that allows a precise time stamp of 1µs.
>Lenze 8400 series inverters are connected over EtherCAT, which was chosen because it is fast and deterministic. The inverters have the option of Safe Torque Off so operators can perform work on the plant such as cleaning without the need to power everything down. A variety of Lenze geared motors are used. In the case of the racking pumps which have a high duty and need to deliver a precise volume, type GKR bevel gearboxes were used. These have 96% efficiency, low backlash are virtually wear free.
>The new cask racking plant was opened by broadcaster Nigel Barden assisted by head brewer Roger Ryman. Microdat had installed a VNC (Virtual Network Computing) which allows remote control of mouse and keyboard with return relay of screen updates. As VNC is platform independent, Nigel Barden was able to start the plant on an iPad.