When the milk arrives at the Orkney Cheese Company creamery facility, it is first pasteurised to kill any harmful bacteria. The pasteurisation process takes the milk up to a temperature of 72.6°C and keeps it there for 18 seconds. The milk then goes through a separator before entering the cheese vat at 33°C. The whole process is recorded using a four-pen ABB C1900 circular chart recorder. The C1900 records the flow rate, which should be 13,000 litres an hour to meet production schedules, and the temperatures achieved during the pasteurisation process.
The chart also records clean in place wash-downs, noting the duration and temperature of the wash water, with the resulting data being used to check that the production equipment is being properly cleaned.
Different colour pens record the pasteurisation temperatures and the length of time of washing, with each paper chart representing one day’s production – four vats worth of pasteurising plus the clean-in-place wash.
“We have always used ABB recorders and have always found them to be very reliable and easy to use.”
As well as the milk pasteuriser, additional C1900 recorders are also used on the cream pasteurizer and the milk silos to record the storage temperatures. This recorder has an input from the 60,000 litre milk silo, one from the 15,000 litre milk silo and one from the wash system.
Leigh Shearer, maintenance engineer for Orkney Cheese Company, says: “We have always used ABB recorders and have always found them to be very reliable and easy to use.”
Maintenance is also minimal, ensuring the recorders are almost constantly available to measure process parameters. Says Leigh: “The only maintenance I need to do is to replace pens and some minor components. The recorders do not get washed down but do operate in a moist environment. Because the recorders are protected to IP66, we have not had any problems with corrosion.”
“The ABB recorders have served us well because in 17 years we have had no major problems with them.”
The reliable performance offered by the recorders is particularly important given the site’s remote location, with Orkney situated 10 miles off the northern coast of Scotland. “Reliability is very important to us because we are quite isolated and spare parts can take some time to reach us. The ABB recorders have served us well because in 17 years we have had no major problems with them.”
The paper charts make it very easy to analyze production history. “We use data for analysing anomalies,” adds Leigh. “Our cheese is graded every three months – if one batch has an issue, we can check back with the charts to see the temperature records and work out what was causing it.”