During standby periods without active loading, heat-treating plants continue to require, among other things, electrical energy, cooling water and, if necessary, natural gas and/or other process gases. However, this not only causes costs, but also has an impact on CO2 emissions.
If a plant will be shut down for an extended period of time, standby scenarios such as weekend or holiday routines should be activated. Auxiliary equipment such as washing machines, generators, and re-cooling and exhaust systems must also be taken into account.
These scenarios include reducing the furnace and oil bath temperatures or “degassing” the system. It depends on whether and when the respective situation makes sense. With an unregulated generator, it makes little sense to degas the furnace and burn off the excess endogas on the generator. Smaller savings measures like switching off individual oil circulators in standby or reducing the speed to the necessary minimum can be implemented in the short term.
The circulators can be operated in “rotary cycle” so that there are no permanently unmoved zones. In the case of heating the oil bath, it must be ensured that there is an even flow around the heating elements. Frequency control can also be implemented in hot gas circulators and air compressors. This control technology can be retrofitted, but additional control cabinets may be required.
For all energy-saving measures such as standby and weekend automation, care must be taken to ensure that the peripherals are suitable for this. For example, water re-cooling should only be switched off if the manufacturer provides for such operation. Cooling water circuits must be flushed appropriately before shutdown, and water tanks in washing machines should be emptied or treated to prevent undesirable changes in the cooling water.
With any shutdown, it is important to consider the time it takes to restart – the more components that are shut down, the longer it takes. Therefore, minimizing consumption while maintaining operational readiness is often the most efficient method.
Want to learn more? Our experienced Ipsen team will be happy to advise you on the implementation of energy saving measures. Contact Matthias Rink at +49 2821 804 287 or Energy@Ipsen.de.