Milk Pipe Research

The Challenge

In preparation for future development, it has become more common for dairy farmers to put their milk storage at the entrance of their farm and away from their milking parlor. This can create distances of 100 yards (91.4 meters) or greater for delivering milk. Transferring milk over a long distance generates a concern that the milk could become warm and damage fat globules. If these globules are damaged, you will see more free fatty acids, which would threaten the quality of your milk.

The Journey

Paul Mueller Company partnered with Dairy Campus in the Netherlands and FrieslandCampina to investigate this concern. We researched the quality of the milk after it traveled through a 220-meter-long delivery pipe.

The study begins by running milk from the buffer tank through a plate cooler, before it enters a 1.6 inch (40mm) stainless steel pressure pipe. The plate cooler brings the milk down to 38.5ºF (3.6ºC) with ice water and then enters the pipe. After traveling more than 218 yards (200 meters), the milk is transferred to the silo tank. As the milk arrived, it was measured at 38.8ºF (3.8ºC), just slightly rising from its original temperature. The milk was below the required 39.2ºF (4ºC), and therefore was delivered cold.

The Solution

Pumping deep-cooled milk long distances does not have to be detrimental to the milk quality. Developing a smart and efficient milk cooling system will ensure that the distance between the milking parlor/milking robot and the milk cooling tank will not matter.

The plate cooler and chiller cool the milk to 38.5°F (3.6°C), which releases a lot of (low-value) energy. A water-cooled chiller can completely convert this energy into hot water, which can be used for cleaning. The heat from the milk can also be used to heat offices or homes, which saves energy in the long run.

The Results

Pumping hot milk over long distances can damage fat globules, as measured by the increased free fatty acids. However, when cooling the milk first and then transferring it, the free fatty acid levels stayed constant at 0.2 to 0.3 meq per 100 grams of milk fat, below the required national average. See the full research results from Dairy Campus and understand how cleaning the pipe plays a role here.

The milk's direct cooling and cold pumping positively influence the free fatty acids. This research helps ease farmer concerns, proving that with the proper cooling system in place, long delivery pipes do not threaten the quality of their milk. With this information, dairy farmers can extend their piping, allowing for more flexibility in their farm designs.