- Everything from a single source
- Fulfilment of directives and ATEX standards
- Low space and installation requirements
- Fewer downtimes
- Better process reliability
As part of a modernization programme, Bürkert’s fluidics experts were commissioned to design a decentralized solution for controlling process valves with a view to replacing the old valve control systems for Huntsman. The Huntsman textile chemicals company manufactures finishing chemicals for clothing, home textiles, technical textiles and digital textile printing at its factory in Langweid am Lech. Bürkert and Huntsman have been working together closely for many years, a cooperation that began in 1982 when this location was constructed.
Focus on safe technology
Production facilities in which flammable and explosionrisk materials are used require comprehensive maintenance. Safety-related technology is at the focus here. At Huntsman, plant modernisation is carried out in rotation and according to the planned overhaul intervals. To this end, individual plant sections such as reactors, tanks and pressure vessels are taken out of operation and reconditioned to make sure that they are technically up to date. Special chemicals are produced in batches, so overhauls can only be scheduled between batches.
The first Bürkert products were installed at Huntsman as early as 1982, and some of them are still in operationtoday. In 2004, Huntsman and Bürkert cooperated once again to equip four new systems with intrinsically safe solenoid valve cabinets and valves. Finally, a plant producing 30 different products was modernized in 2015 and provided with a new enamelled boiler. At this point the outdated control technology was also replaced, and a new, decentralized process control system and a new PLC level were introduced.
More than just a control cabinet
The control cabinet system solution for the pneumatic automation system of the process-related plant sections means that, in combination with the newly introduced Emerson DeltaV process control system and the WAGO PLC level, the plant engineering is now state of the art. As part of the modernization programme for the boiler plant, a completely prefabricated, ready-to-connect and ATEX certified control cabinet system solution for the field automation was installed, including failsafe and intrinsically safe signals.
This system solution comprises the Type 8616 control cabinet (ATEX Zone 1 approved), with a Siemens decentralized ET 200iSP peripheral system and a Type 8640 valve block with Type 6518 safety valve and the Type 8650 valve island. This solution takes up considerably less space and is easier to install. In addition, the customer commissioned Bürkert to set up a safety-related switchover system using pneumatic step chains that allows the system to switch over to an external pressure accumulator if the compressed air or electricity supplies fail.
Hot Swap without downtimes
The signal inputs and outputs of the ET 200iSP and the valves used in the control cabinet are intrinsically safe. This means that maintenance can also be carried out during operation and under ATEX conditions. The high plant availability is optimized through the pneumatic P-shut-off in the base valve block. So in addition to the electrical Hot Swap, it is also possible to carry out a pneumatic hot swap.
Flexibility in the control cabinet
The Type 8650 valve island is used for controlling the pneumatic functions and is also ATEX certified. Thanks to the modular design of its pneumatic and electrical interfaces it is capable of coping with complex control tasks. By apposing the pneumatic modules with varying numbers of valves it is possible to set up 4 to 64 valve functions on a valve island.