Siemer adds a 'showplace'

by Arvin Donley
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Siemer Milling Co. has found practically everything that a producer of wheat flour could want in Hopkinsville, Kentucky, U.S.

"We’ve had great success here since we first turned on the mill in 1995," Richard Siemer, president of Siemer Milling, told World Grain. "We came here because of a relationship with a major customer. Within three years, another company that has become a very major customer re-located in the area. We’ve had great support from the community. We’ve had great support from the (wheat) producers in the area. This is one of the great soft wheat growing areas in the country."

So it’s not surprising that after completing a search for potential sites to expand its flour milling capacity, which included a look at several locations outside of Kentucky, Siemer Milling’s management concluded there was no place like home.

"We decided the best opportunity was here," Richard Siemer said. "Our major customers here were also expanding. We have an excellent workforce, and all the infrastructure was in place."

Siemer Milling added a "C" mill with an additional 5,000 cwts of capacity at Hopkinsville, bringing total capacity at the complex to 16,000 cwts.

Even before the expansion, the Hopkinsville mill was the larger of Siemer’s two mills. The company’s mill in Teutopolis, Illinois, U.S., has 10,000 cwts of daily capacity.

The C mill began producing flour in March and a grand opening was held on June 17. Among those attending the ceremony were several longtime Siemer Milling customers as well as officials from the three companies that worked together to complete the 12-month project: milling equipment manufacturer and engineer Buhler Inc., Plymouth, Minnesota, U.S.; construction engineering firm Todd & Sargent, Inc., Ames, Iowa, U.S.; and Sioux Center, Iowa, U.S.-based Interstates Electric, a designer and installer of electrical systems.

"I don’t know if we could have picked a better team for the project," said Vernon "Red" Tegeler, vice-president of production for Siemer Milling. "Everybody was on board with what was going on. We met all of our target deadlines. It just went very well."

And just as important as getting the construction and installation completed on time, the mill has performed in a highly efficient manner with very few problems since the day it opened, Richard Siemer said.

He noted that the mill reached its targeted yield by the second day of the startup.

"At this point, having had the mill in operation for about three months, as we look forward another 18 months to two years, it appears the decision was an even better one than we imagined at the time," he said.

Tegeler said the company had specific goals it wanted to accomplish with the addition of the C mill. Besides the obvious goal of adding capacity, Siemer Milling wanted the mill to be highly automated, easy to operate, energy efficient, to feature the highest level of sanitation and to operate without additional manpower.

"And we wanted to use the newest and most proven technology," Tegeler said.

Richard Siemer said he believes the C mill is the first in the U.S. to incorporate all of the three elements in the latest generation of Buhler milling technology: the Antares roller mill, the Sirius plansifter and the WinCoS.r2 control system.

"Above all else, we wanted this mill to be a showplace," Richard Siemer said with a smile. "We wanted anybody familiar with flour milling to be stunned when they walked into this plant, both by its appearance and its efficiency."


One of the first things those touring the facility at the grand opening noticed was the mill’s state-of-the-art cleaning house section.

A chain conveyor moves wheat from two "dirty" bins into the cleaning house where it is processed through separators, scourers, aspirators and sterilators before flowing through Buhler Sortex Z3 and Z1 optical sorters. Tegeler noted that 100% of the wheat runs through the Z3 optical sorter and the rejects are sent through the Z1 to be re-sorted. The optical sorters have done a good job of rejecting wheat infected with vomitoxin, the company said.

"So far, from what we’ve seen, it’s been working very well," Tegeler said of the Sortex equipment. "We’re able to get the job done with less equipment and more energy savings, and we’ve taken less of the good product out; we’re doing a better separation."

The wheat not rejected by the color sorter is collected by a chain conveyor and moved into three tempering bins, each with a 100-tonne capacity. The bins are monitored by the Buhler Win-CoS.r2 control system

"With the WinCoS.r2 program we have the capabilities of tempering wheat into all three bins so the tempering time is the same," Tegeler said. "We are able to layer the wheat into each bin and pull the tempered wheat out equally so we get a uniform mix all the time."

For a second cleaning, the wheat comes out of the tempering bin through flow balancers onto a chain conveyor and back up the leg where it goes through a second temper and is then passed through a magnet, scourer, sterilator and aspirator before arriving in the first break bin.

The wheat then passes through Buhler’s Antares roller mills, including two double-high roll stands and 10 single stands.

"The roll stands are working remarkably well," Tegeler said. "It’s amazing how quiet they are compared to other roll stands we’ve had, and they are designed for ultimate sanitation."

Also featured in the milling section are Buhler Sirius sifters with a stainless steel design, pneumatic receiving cyclones and stainless steel spouting.

Tegeler declined to give an exact flour extraction rate for the C mill, but he noted, "Our goal was to produce high extraction flour, and we’ve definitely accomplished that."

Flour storage bins with a total capacity of 200,000 cwts are located on the top floor of the mill along with bins that are designed for 200,000 cwts for storage for bran and millfeed.

Before going to the six loadout bins, which are on load cells and each have 120,000 pounds of storage capacity, the finished product passes through a foursection rebolt sifter with Novapur sieves as well as an inline NIR, a metal detection unit and sterilator. The loadout bins are located over a driveway for both rail and truck loading.

Richard Siemer noted that there is space in the new building for future expansion.


Making the C mill one of the most highly automated mills in the U.S. has helped Siemer Milling accomplish two important goals: it is able to produce more flour at its Hopkinsville facility without adding labor costs and it is able to operate using less energy than it would have otherwise.

"We wanted this mill to be very energy efficient and we wanted to run it even more automated than the original mill, because our intentions were to set this unit up for longer runs, to be able to run it somewhat lights out," Tegeler said. "Even though we always have millers on duty operating the other two units, our intention was that we weren’t going to have them going back and forth into the new unit as much."

At the heart of this "somewhat lights out" approach is the Buhler WinCoS.r2 computer control system.

Tegeler said all the equipment in the mill is connected to a Profibus (Process Field Bus) data highway so there is highspeed information constantly being gathered on each piece of equipment.

"We can put all the job cues in and pretty much let the mill run," Tegeler said.

Many of the energy-efficient features in the mill are also tied to the WinCoS.r2 system, he said.

"We have frequency controllers on the pneumatic fans to maintain the air velocity we need, but yet not too much," Tegeler said. "The lighting in the facility is also more energy efficient since we are now using fluorescent lights."

With food safety regulations becoming stricter with each passing year, it’s not surprising that Siemer Milling made sanitation a point of emphasis in its new mill.

"We definitely looked at the different opportunities with different technology available to make sure we would be producing a product that adhered to all the food safety regulations, especially regarding the big issues of microbes," Richard Siemer said.

"We wanted to do a better job of cleaning the wheat, so we really focused on using the best technology in the cleaning system. Also, in the milling process we went with stainless steel in the spouting, the roller mills and the new sifter technology with the Novapur sieves."


In addition to increasing its milling capacity, Siemer Milling added a corrugated steel grain bin with a storage capacity of 530,000 bushels. The new bin sits next to a 740,000-bushel steel bin that was installed in 2008.

With the Hopkinsville facility sitting in the middle of one of the most productive soft wheat growing areas in the U.S., Siemer Milling typically has no trouble filling those bins.

In a typical year, about 95% of the wheat used by the Hopkinsville mill is sourced within a 75-mile radius of the plant.

Richard Siemer credited the wheat producers in the area with being innovative and willing to adopt new technologies very rapidly.

"We have a very reliable source of raw material near this plant," he said. "Fifteen years ago people around here would have been thrilled to have 65-bushel-per-acre wheat yields. Now everybody is disappointed with that. All of us have grown together and it has brought us to a new plateau as well as them."

Unlike most other parts of the country, wheat hasn’t been losing the acreage battle to genetically modified corn and soybeans in the Hopkinsville area.

"In this case, we define success by acreage not having decreased over the last 10 years," he said. "Any place that’s been able to maintain wheat acres is pretty impressive."