Hammer mills and roller mills offer two different solutions for grinding in feed mills, but which is best? The choice of equipment affects costs and final product quality, so selecting a roller mill or a hammer mill for animal feed is important.
RMS’ Territory Manager, Luke Zebroski, talked to Jim Voigt about the issues many feed mills face when considering upgrading from grain hammer mills to roller mills. Known as Grain Guy Fifty, Jim has 50 years of experience in grain and animal feed, and chatted with Luke about the need for mills to evolve and update as technologies change.
What’s the Difference Between a Roller Mill and a Hammer Mill?
Particle reductionis an essential aspect of feed production. It enhances the nutritional value of the feed, provides a more homogenous mix, and improves pellet durability. There are two primary types of equipment feed mills use for this processing step:
- Hammer Mill: A hammer mill uses hammers to smash grains against a screen. The particle size is dictated by the screen size.
- Roller Mill: Roller mills use pairs of corrugated rolls that shear the grains. Particle size is dictated by the spacing between the rolls.
Many facilities use one or the other, but some use both. There is room in the market for both types of machines, depending on need. Roller mills offer control over more variables. There are also important differences in the final product, energy efficiency, and costs:
Final Product
Both machines can hit specific particle size targets. Roller mills offer more consistency in achieving the desired particle size range. The range is tighter because, as Luke explains, “How we’re able to control that tight particle size distribution is because we’re taking small bites all the way down that machine, small controlled bites and not trying to overprocess the grain,” which is what happens in a hammer mill.
It’s also important to note that the spread in particle sizes gets larger over time with hammer mills, as the hammers and screens wear down.
Efficiency
A roller mill is more efficient to operate, which means that, ultimately, it costs less to run than an animal feed hammer mill.
Maintenance Costs
Automation and newer technologies have helped extend the life of rolls, requiring less downtime and maintenance, but a hammer mill for feed grinding is still cheaper to maintain. The parts don’t need to be changed out as often.
How Do Installed and Operating Costs Compare?
These are all important differences, but as Luke says, “With customers, where the light bulb really comes in is when you start looking at what I call total cost of ownership, your upfront cost of the piece of equipment, the maintenance, and the energy, over the next 10 years.”
A lot of customers fail to consider this important factor. They look at the initial project and installation costs and ignore what the setup will cost over 10 years of operations, a vital consideration with such a big investment. Over the years, a roller mill offers a lower total cost of ownership.
Does Frequent Commodity Switching Favor One Machine Over the Other?
As Jim brought up the issue of changing grains, or commodities, in a feed mill, “When I compare the two machines as far as changing back and forth on commodities, obviously, with the hammer mills I’m changing screens, and I couldn’t change the speed.”
The roller mill is the clear winner for changing between different grains. You can stop the feeder on the fly, make a small adjustment, and start up quickly again with a new grain. Hammer mills require up to an hour of downtime to make the necessary adjustments.
A fully automated roller mill setup can include up to 16 different recipes, including both roll gap and roll speed, allowing for easy switches between several different commodities and particle sizes.
If Roller Mills Are Often the Better Fit, Why Do Mills Hesitate To Switch?
If roller mills are superior, it’s important to understand why some mills still hesitate to make the upgrade. As Luke explains, “A hammer mill is a legacy piece of equipment.” It can be hard for companies to make the switch from a machine they’ve depended on for so many years. As Jim put it, “People are afraid of change. We don’t like change, and most of us try to avoid change.”
The other important reason mills hesitate is the initial cost. The price difference between the two technologies is significant, and not everyone sees the bigger picture of the total cost of ownership.
What Does RMS Do Differently to Overcome That Hesitation?
RMS shows suppliers the data, and we make the case for a roller mill, but many still hesitate. We do several things to help customers overcome the hesitation and to make the change more comfortable, and it’s what sets us apart from competitors.
We go on a journey with our customers from start to finish with an end goal and target results in mind on day one. According to Luke, “You cannot be a successful machine manufacturer without service after startup.” RMS keeps coming back onsite for hands-on, repetitive training, often quarterly. With turnover, we continue providing training for new employees.
Success in the feed industry requires change and updates, relying on the newest technologies that offer efficiency, lower cost of ownership, and better final products. Those who refuse to change don’t stay in the industry.
At RMS, we’re excited to be at the forefront of change. If you’re thinking about making the upgrade to roller mills, contact us to discuss your questions.
