Milk cooling tanks maintenance advice

2007-07-10 11:41
Sales manager

Milk cooling tank is an essential part of the milk process. Badly kept, it will be less efficient, with a higher electricity consumption and damages milk quality.

Daily maintenance :

1) For the first milking turn cooling on when the volume of milk is sufficient to be agitated correctly (wait until blade is submerged).
Starting refrigeration too early will cause some problems : ice development at the bottom of the tank, which blocks the blade/agitator and breaks the engine. It also increases lipolysis, and damages the compressor due to the circulation of the freon in a liquid state (freon stays as cold as at the beginning of its circuit).

2) After emptying the tank the inside needs to be cleaned right away. The exterior of the tank needs to be kept clean (do not use steel whool). You particularly need to clean the tank outlet after each milk collection, interior and exterior, in order to avoid milk contamination risks when pumping from the bottom of the tank.

3) Do not store anything (bags, boxes, cans,...) in front of the condensing unit. It has to be totally clear in front of it. A big quantity of air needs to circulate around the condensing unit. In fact, for a 600 litre tank, you need 1500 m3/h at 18°C.

Once a month :

1) Make sure the holes of the spray head inside the tank are not clogged up.

2) Make sure that your are using hot water for the CIP (65°C minimum, fats dissolve from 55°C), and alternating the acidic soap and chlorinated alkaline, with the right doses. Be careful not to adjust water too hot, it would buckle the stainless steel and some soldering (connecting exchange plate and circulation tube) could be damaged. You also need to be careful about the type of water used for cleaning the milk cooling tank (non-drinkable water from a well for example). If water is not treated correctly, it could cause settling or corrosion. It is recommended to use drinkable water. In any case, the last rinsing needs to be done with drinkable water.

3) Check that there is no settlings inside the tank.

4) Check that the agitator rotates 2 minutes every 13 minutes (cycle of 15 minutes) when milk is already cooled down.

5) Check that the CIP drain valve (selenoid valve) is not leaking.

Once a semester :

1) Clean up the radiating plates of the condensing unit (radiator) with a dry brush (water would clog it, and do not use a wire brush) or with compressed air. If condensing unit is clogged, it will cause :
- overheating of the refrigerating compressor, leading to the problem of a fan which will burn out.
- a longer time of cooling milk, which means germ development and electricity overconsumption
This goes with the proper aeration of the parlour : heat needs to evacuate correctly. It needs to have an entrance (at the bottom) and a way out (at the top). If it is very hot during summer, the ideal would be to create a draught while the tank is cooling the milk.

2) The thermostatic control can be defective or bad adjusted. Make sure the milk temperature is situated between 2 and 4°C. Cooling needs to be finished 1h30 to 2 hours maximum after the end of milking.

Once a year :

1) The solenoid valves of the CIP water arrival are equipped with filters. It is useful to clean those once a year.

2) Check the right levelling of the tank, otherwise the measured quantity of milk woulb be wrong. This is a quick way to loose money !

Once in the tank's life :

1) Take a copy of the calibration sheet and shelter the one in the parlor from dirt.

2) The condensing unit needs to be placed far from :
- the exhaust of the milking machine's vacuum, otherwise oil would plug up the radiating plates
- the stocks of flour or cattle's aliments which provides a lot of dusts when manipulating. 

3) Place the tank in order to be able to clean around it.

4) The ground needs to be slightly slope in order to avoid water stagnation under the tank. A manhole situated underneath the tank outlet is better, it will facilitate cleaning and draining.

Dernière modification par charriau (2009-02-18 08:56)