Spiral Freezers & Chillers.
In a typical frozen foods manufacturing facility, and many ambient baked goods sites, there are various types of industrial refrigerators and chillers employed to maintain consistent quality, texture, and temperature of products.
Spiral freezers and chillers are one means of refrigeration that are popular with food processors, given their compact spiral belt and their ability to freeze or chill large numbers of products with longer dwell times.
Spiral blast-freezing of food products is the most energyintensive process in a typical frozen foods manufacturing facility, with air temperatures regularly in the range of +5C to -40C depending on the type of product to be frozen or chilled.
Unlike tunnel freezers, which require a long, linear wiremesh belt to convey products through a sub-zero blastfreezing room, spiral freezers use self-stacking, multitiered belts to maintain product quality and minimize the refrigeration space required in the plant. Most modern spiral freezers offer a high level of customizability and are generally fairly easy to install on the plant floor.
What We Monitor.
ROI
22%
Energy
-10%
Operations
Better Operational Data
12 months
Payback Period
Maintenance
Avoid breakdowns
Sustainability
Reduce emissions
Monitoring.
Energy
The cooling process is typically supplied by a centralised ammonia refrigeration compressor, distributed either directly as ammonia, or indirectly through a glycol system.
- Energy transfer from the cooling fluid to the chiller is measured by monitoring the flow rate & temperature of the cooling fluid.
- Energy consumption for the belt drive motor is measured from the inverter drive or using CT clamps on the power line
Operations
Where the chiller is controlled by a local PLC, this data can be collected to enrich the energy & maintenance data, providing vital operational context for different operating modes such as production or defrost.Maintenance
Monitor leading indicators of failure:
- Current & Torque: Drive and chain loadings
- Vibration: Gearbox lubricant condition at low temperatures
- Ultrasound: Bottom bearing wear
Indicative Savings.
Energy
A 500kg/hour freezer, operating at -20C typically consumes circa 250kW of cooling. Assuming the fridge has a CoP of 3, this represents about 80kW of electricity, or around
£100,000/annum cost (at June 2022 prices).
Improving heat transfer by 10% will save around £10,000 per annum.
Operations
These items of equipment are such that, from an operational perspective, there is limited opportunity to improve.
Maintenance
A typical failure could take 24 to 48 hours to fix and lead to a shutdown of the line. At an operating value of around £1,000 per hour, together with the scrapping of all the product currently on the line, the consequence of failure could easily be in excess of £50,000.
Indicative Costs & Payback
22% ROI Payback within Twelve months.
Year 1 cost - £12,300
Annual Monitoring Cost - £1,800*
Hardware costs - £8,500
Commissioning - £2,000
* This represents the chiller's share of the annual monitoring fee.
Hardware
Required hardware will depend on type of data collected and variables monitored:
- Temperature sensors at key points in cooling system, if not available from process control data.
- Vibration sensors—monitoring chain drives, gearboxes and
any fans
Commissioning
Our specialists configure the system and run end-to-end testing prior to go-live.
Monitoring Cost
Annual service fee, based on the total number of parameters measured on a specific site. The values used in this illustration are based on monitoring 13 parameters for this asset type.
Actual implementation may use more or fewer parameters than this example, depending on requirements.