We’ve just finished work at a food processing site, optimising three blast freezer tunnels. The site recently made a significant investment in VSDs to take advantage of the large energy savings potential. Unfortunately the energy savings came at a cost as reducing fan speeds increased occurrences of product temperatures missing targets. Our role has been to optimise the use of fan VSDs.
We found that occurrences of missed product temperature targets were intimately linked to the defrost-in-progress system that was used to keep the tunnels operational for longer periods of time. Load matching fan speed schedules were developed for each tunnel. The scheduling was able to offset the negative impacts of the defrost-in-progress on product temperature while achieving significant energy savings.
The results have been fantastic:
- Reduction in missed product temperature targets of 94%
- Energy savings equivalent of $86,400 per annum (0.8 GWh)
- Payback of less than 4 months
Its rarely only about energy; production, Health and Safety or Environmental improvements are a regular byproduct of efficiency projects.