Siemer Milling Expands Flour C Mill, Adds Whole Wheat D Mill in Kentucky
Siemer Milling Co.’s largest flour mill just got bigger. Over the course of 2019 and 2020, the company added 1,500 cwts. per day of capacity to its existing C mill, which processes soft red winter (SRW) wheat into white flour, bringing it up to 7,200 cwts. Siemer Milling also added a 2,500-cwt.-per-day D mill dedicated solely to grinding whole wheat.
All of this was done without constructing any new building space at the Hopkinsville, KY mill (270-475-9990). Total capacity at Hopkinsville now stands at 21,000 cwts. per day.
“We just needed additional capacity,” says Plant Manager Mary Gleason, who came to Siemer Milling in 2017 from the General Mills Avon plant in Carlisle, IA. “We grow as customer demand grows.”
Just prior to the C mill expansion the entire plant’s software system was updated to Bühler’s Mercury operating software. Most of the plant was running on WinCos with the exception of the elevator that had been operating off the original 1995 program prior to the project.
Siemer Milling anticipated the C mill project as early as 2010 by installing steel plates in the floor for additional equipment.
As for the whole wheat D mill, Gleason says, “We were able to shoehorn that around the C mill with the space that we had. The two mills are sharing a cleaning house, which saved a lot of space.”
The Hopkinsville mill itself dates back to 1995 and was originally just one unit at 7,000 cwts. per day.
The mill expanded several times over the next quarter century and now has four separate milling units with a total capacity of 21,000 cwts. per day.
The D mill has no rollstands at all, relying on a unique all-hammermill flow that Bühler developed.
The D mill portion of the $4 million project was the first to be completed, with work begun in September 2019 and startup in December. The C mill expansion spanned the same months in 2020.
Shared Cleaning House
The project saved Siemer Milling both space and expense by reworking the C mill cleaning house to be shared by the D mill.
This was possible because the facility already had a tempering bin in place that wasn’t being used by the C mill. That bin now is dedicated to whole wheat.
Siemer upgraded to a larger Bühler MOZL dampener turbolizer, which handles all of the water management functions for both mills.
The cleaning house can swing between tempering for C mill or D mill with a simple recipe software change.
Additional upgrades to the cleaning house:
- A second Bühler Sortex three-channel color sorter was added to pick up the increased volume.
- A second Bühler MVRT aspiraton filter was added.
- Motor and drive sizes were increased throughout the cleaning house wherever needed.
Whole Wheat Mill
All of the wheat grinding for the 2,500-cwt. D mill is done on a large, heavy-duty 250-hp Bühler Multimpact- Fine hammermill.
Gleason notes that the single-hammermill flow takes less equipment and consumes less energy than a conventional roller mill flow.
“We were planning to adjust the granulation by changing screens or altering the speed through the variable feed drive (VFD) and utilizing the Bühler MYTA particle size analyzer to monitor and control the granulation,” she says. “In practice, though, we saw minimal granulation change, so we’re producing a single granulation, which is a finer whole wheat flour than we would get from roller mills. A number of our bakery customers find that attractive.”
Whole wheat kernels reach the hammermill from the cleaning house via a Bühler TUBO tubular push conveyor. This relatively new technology uses a unique mechanical conveying element made of food-safe composite materials pushing grain through a tube. Due to its design, the TUBO often is used to take the place of an elevator leg and two horizontal screw or drag conveyors. Gleason says the TUBO unit at Hopkinsville is the first to be utilized by Siemer Milling.
The only milling step following the hammermill is a single-section Bühler MPAS Seginus Plansifter, which acts as a rebolt sifter before finished flour is sent on to packaging lines or truck loadout bins.
Expanded C Mill
Adding another 1,500 cwts. of daily capacity to the C mill required the addition of two more rollstands – a Bühler MDDR Antares single-high, four-roller mill and an MDDT Antares double-high, eight-roller mill.
Gleason says the single-high mill handles first break and first sizing, while the double-high is dedicated to two third breaks and a fourth and fifth break.
Also added to the C mill:
- A Bühler MPAK four-section Sirius plansifter.
- A Bühler MQRG Polaris purifier, the first purifier on the C mill.
- Three Bühler MJZI impact machines located beneath three of the rollstands.
- A Bühler MKZH vibro duster.
- The size of the pneumatic fan was increased.
Ed Zdrojewski, senior editor
From Second Quarter 2021 MILLING JOURNAL
Siemer Milling Co. • Teutopolis, IL • 217-857-3131
- Founded: 1882
- Milling capacity: 41,500 cwts. per day at three locations
- Products: Hard red winter, soft red winter, and whole wheat flours; wheat germ, food-grade flours, millfeed, red dog, and a variety of specialty products such as heat-treated flours
- Annual sales: $240 million
- Number of employees: 175
Supplier List
- Aspirators............................. Bühler Inc.
- Blower................................. Bühler Inc.
- Bran finishers........................ Bühler Inc.
- Color sorter........................... Bühler Sortex
- Conveyors............................ Bühler Inc.
- Dampener............................ Bühler Inc.
- Electrical controls.................. McAfee Electric, Inc
- Hammermill......................... Bühler Inc.
- Impact machines................... Bühler Inc.
- Magnets............................. Bunting
- NIR analyzer........................ Bühler Inc.
- Particle size analyzer............. Bühler Inc.
- Pneumatic system................. Bühler Inc.
- Purifier.............................. Bühler Inc.
- Roller mills......................... Bühler Inc.
- Sifters............................... Bühler Inc.
