Processing / Case Studies & Field Reports

Milk drying optimization pays off

October 4, 2012
/ Print / Reprints /
ShareMore
/ Text Size+
Trans

Processor improves operational efficiencies and increases yields by reducing moisture variability on its dryers.
 
The engineers at Murray Goulburn Cooperative are acutely aware of the complexities involved in the milk drying process. Murray Goulburn is Australia’s largest milk processor and one of the country’s largest exporters of processed foods. Two years ago, it adopted a new system to automatically monitor and precisely control the most critical part in the manufacture of powdered milk—the final drying stage.
 
Murray Goulburn’s operation near the village of Koroit (Victoria) uses four dryers with capacities from 1.2 to 7 tons per hour to process skim milk and whole milk into a variety of dairy-based powders. The dryers have steel chambers, standing up to six stories high and 66 feet in diameter. 
 
One of the critical variables that affects the quality of the powder is its moisture content. Depending on its end use, the powder should contain between approximately 3 to 6 percent moisture. The key to achieving the right moisture level is to control the temperatures of the air entering the tower, static fluid bed and vibrating fluid beds.
 
In the past, plant operators manually changed temperature setpoints to control throughput and moisture content. These decisions were based on the operator’s experience and using feedback from moisture samples taken once an hour. Tests on samples taken every hour showed the moisture would often vary by as much as 0.3 percent. To create a more consistent product, the temperature setpoints would need to be adjusted automatically, based on a predictive model of the dryer.
 
“We knew we needed an automated system to reduce the moisture variability of the powder,” says Geoff Rome, automation and utilities engineer at Murray Goulburn. “Our goal was to find a solution that would help us maintain consistent quality while increasing final product throughput.”
 
To meet its goals, Murray Goulburn selected Rockwell Automation’s dairy dryer solution, based on Rockwell Software’s Model Predictive Control (MPC) and Optimization technology. The Predictive Quality–Soft Sensors system continually collects data every 15 seconds from each dryer and uses predictive models to calculate optimum temperature setpoints for controlling and maintaining the desired moisture level during production.
 
The software manages variations in the milk solids concentrate as well as incoming air, humidity and other factors that affect drying efficiency. By reducing moisture variability, the average moisture target can be increased without compromising product quality. This allows higher yields to be produced from the same milk solids, increasing dryer capacity and reducing energy usage per ton of finished product.
 
 “The MPC solution from Rockwell Automation performs as well as your best operator, 24 hours a day, seven days a week,” Rome says. “The result is the highest-quality product—consistently.”
 
With the implementation of the model predictive control solution, the moisture variability levels in each dryer were reduced on average by 52 percent, far exceeding Murray Goulburn’s expectations of 35 percent. As a result, the company has produced on average  an extra ton of powdered milk product per day across its four dryers. 
 
For more information:
Ian Steele, 512-438-1400, isteele@ra.rockwell.com

Did you enjoy this article? Click here to subscribe to Food Engineering Magazine.

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

Fabulous Food Plant: Paramount Citrus

Learn more about this fabulous food plant in Food Engineering's article, found here.

Podcasts

Burns & McDonnell project manager RJ Hope and senior project engineer Justin Hamilton discuss the distinctions between Food Safety and Food Defense as well as the implications for food manufacturers of the Food Safety Modernization Act.
More Podcasts

What was your favorite part of FA&M 2014?

View Results Poll Archive

THE MAGAZINE

Food Engineering Magazine

Food engineering magazine 2014 april cover

2014 April

Catch a preview of the Powder and Bulk Show in this April 2014 edition of Food Engineering. Also, be sure to check out a coffee stick making a real stir and a major advancement in the the pet food industry.
Table Of Contents Subscribe

THE FOOD ENGINEERING STORE

Food-Authentication-Flyer-(.gif
Food Authentication Using Bioorganic Molecules

This text provides critical tools and data needed to augment routine food analysis and enhance food safety by aiding in the detection of counterfeit, and potentially deleterious, foods.

More Products

Clear Seas Research

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications,Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

Food Master

Food Master Cover 2014Food Master 2014 is now available!

 

Where the buying process begins in the food and beverage manufacturing market. 

Visit www.foodmaster.com to learn more.

STAY CONNECTED

FE recent tweets

facebook_40.pngtwitter_40px.pngyoutube_40px.pnglinkedin_40px.png