Chill milk, save money, meet regulations

Chill milk, save money, meet regulations

30 October 2017

A dairy farm near Rotorua proves it is possible to cool milk quickly, save money and meet regulations.

Meeting the new milk cooling standards and saving money on power can be done. Just ask Lachlan McKenzie. He and farm manager Andrew Grant achieve both on their Kaharoa 900-cow farm, thanks to a PROMAX insulated 30,000 litre (l) tank.

On June 1st 2018, new milk cooling regulations come into effect for the cooling of milk from the cow to the collection tanker. In the vat at collection time, milk now has to be chilled to six degrees within two hours of completion of milking.

Lachlan’s farm has been retrofitted to meet the new rules and he saves $350 a month on his cowshed electric bill, which he says is all down to the Promax Tank.

At the heart of the system is the ‘double bank plate cooler.’ This lets milk flow through each side of the cooler unit. On the left it is chilled from the cow at around 37 degrees, by ordinary spring or tank water at around 14 to 16 degrees, as in most farm dairy sheds. That brings the milk down to around 16 to 18 degrees. The milk continues its journey around the plates (this time on the right-hand side), that run to and from the insulated tank with the water at six degrees. This brings the milk into the collection vat at around eight degrees, sometimes less. So, all the collection vat has to do is lower it by another two degrees at most.

This not only saves money but it is also incredibly quick.

“What I really like,” says Andrew “is its simplicity and automatic operation.”

The fully automatic operation of the new system means little training is needed to have it working optimally.

“The system is quick because the Promax tank water is chilled overnight on low rate power. It means we are not spending time and energy on chilling liquid after milking, other than the cow’s milk,” says Andrew.

Partially burying the tank by just over a metre was also used to good advantage as it both helps to keep the chilled water cold and also cools the returning water from the double bank plate cooler.

“When I undo the tank lid and feel the temperature of the water at around midday, in full sun it is shockingly cold. The temperature gauge on the PROMAX tank read two degrees after milking and yet there is no condensation on the outside of the tank,” says Andrew.

To chill this water down again following milking Andrew uses the same 25 kilowatt (kw) chiller hooked up to the milk vat through which the insulated tank water is pumped, using off peak overnight power. Then the 30,000 litre tank easily copes with the daily production from the 900 cows.

The tank is so efficient at keeping the milk cool that even absorbing 10 degrees off the cow’s milk does not really alter the water temperature much.

Andrew says the retrofit to meet the new regulations was easy in terms of downtime in the shed and space required.

For more information on Promax insulated tanks, talk to your local Technical Sales Rep or visit your local Fonterra Farm Source store.

Article supplied by Promax Plastics