In many respects, the $21 million updating of the ConAgra Mills flour mill in Oakland, Calif., seems to be taken straight from the mill modernization playbook — state-of-the-art equipment with double high rollstands, greater automation and enhanced sanitation. But a deeper look into the project, with investments oriented toward ever higher food safety requirements and energy savings, shows ways ConAgra and its customer base are adapting to a new century.
In addition to the company’s first flour packaging line replacing multi-wall paper bags with low-density polyethylene packaging, the ConAgra Oakland mill features a large swing mill (alternating between whole wheat and enriched flour), light-emitting-diode (LED) lighting, the elimination of wood from the A mill flow and a fleet of highly efficient diesel trucks.
The project raised daily capacity to 14,000 cwts of flour from 10,000. The increase was installed within the A mill, which was completely redone, raising its capacity to 10,000 cwts. Improvements to the B mill included the replacement of filters and a number of sanitation enhancements. Automation was notched up considerably at both units as were centralized energy controls.
Bühler Inc., Plymouth, Minn., supplied equipment and provided engineering for the Oakland project as well.
“They are our preferred milling equipment provider,” said Bradley T. Allen, vice-president of manufacturing at ConAgra Mills.
A number of other companies were involved, including Interstates Companies, Sioux Center, Iowa, which was responsible for the control system and electrical overall. Interstates worked with Nelson Rathert, manager of plant engineering at ConAgra Mills, in connection with automation and electrical. Ebmeier Engineering L.L.C., Glenwood, Iowa, was responsible for the considerable structural work done at Oakland.
Throughout the expansion project, which began in 2009, the flour mill was kept running.
“The longest downtime in the project was 18 hours,” Mr. Allen said. “That’s really tough to accomplish. I don’t have enough credit to communicate about those who were able to complete a project of this size, scale and scope. To be able to do these on the run makes things much easier for our customers.”
Jesse N. Higgins, superintendent at Oakland, added, “We were able to get through the project without any customer complaints.”
A central player in the execution of the “on the run” approach, Mr. Allen said, was SCA Construction, Inc., Independence, Kas., responsible for equipment installation.
“You have to have someone who is a partner when you sequence these on the run,” Mr. Allen said.
The project was the fourth of what Mr. Allen described as a “complete refurbishment” of a flour mill by ConAgra Mills in recent years, following major work done by the company in Saginaw, Texas; Commerce City, Colo.; and in Puerto Rico. Also in recent years was a significant project in Alton, Ill., in which ConAgra updated the roll floors and made a number of structural enhancements.
As is the case with a number of U.S. flour mills, the site at Oakland originally was a grain elevator (dating to the 1920s) and only later was a flour mill added or, in this case, repurposed.
Built as a Farmers Coop elevator, a three-story feed mill was installed in 1946. The facility was converted in 1965 by Montana Flour Mills, which added another two floors as part of installing the A Mill. The mill was acquired by ConAgra Mills in 1967. The B mill was installed in the mid-1980s.
Even beyond the Oakland mill, milling industry investment in California is nothing new. Over the last 25 years, there has been more mill construction in California than in any other state. New mills have been built in Colton, Fresno, San Bernardino and Stockton. As a result, California has the largest flour milling capacity in the United States with 123,800 cwts of daily milling capacity, according to the Grain & Milling Annual, published by Sosland Publishing Co. Kansas ranks second at 112,400 cwts.
R. Michael Veal, vice-president of marketing at ConAgra Mills, said the reason for this investment is hardly a mystery.
“The California economy is huge,” he said. “If California were a country, it would have the ninth largest economy in the world. It’s larger than Russia.”
Comparing California with the rest of the United States is similarly impressive. Its population of 38 million is equal that of the 22 least populous U.S. states combined.
Not only is California large, it is getting larger, Mr. Veal said.
“It is growing post recession, leading the U.S. recovery,” he said. “Unemployment is declining. Incomes are increasing. There are more people, more dollars, more disposable income. The population of the state is growing at a rate of 350,000 per year.”
As part of the project, structural additions were made at Oakland both to handle the heavier equipment installed in the mill and for earthquake protection, Mr. Higgins said.
The mill has endured a number of earthquakes over the years, including a major Bay Area earthquake in 1989 that registered 6.9 on the Richter scale and was responsible for 63 deaths and left up to 12,000 people homeless.
Following that quake, which damaged the Oakland Bay Bridge and required a six-year repair project for the Oakland City Hall, the ConAgra Mills facility in Oakland (4 miles from city hall) was operating again within 24 hours, Mr. Allen said.
In its latest project, a seismic detector was designed and installed at the mill by Mr. Rathert and connected to the control system to offer further protection.
“The key is to get a mill shut down quick when a quake hits,” Mr. Allen said. ”That’s where Nelson’s innovations are so key. You don’t want to tear up the sifters.”
The new milling capacity was installed over the same footprint within the A mill. This was accomplished in part through the installation of double high Bühler rollstands (only on first and second break), Mr. Allen said. Rollstands with 40 inches of milling surface were replaced with 50-inch rollstands. More generally, milling equipment is being designed to be more space efficient, he said.
Another significant source of space savings was the installation of more efficient Bühler filters, reducing the number at the mill to 4 from the 13 sprinkled across the building previously.
Drag conveyors were supplied by Tramco Inc., Wichita, Kas., and blowers by Blower Engineering Inc., Aurora, Ont.
Among the most innovative introductions in connection with the project was the installation of a new packaging system from Premier Tech Ltd. The system has the capability to package flour in poly bags.
Matthew C. Huelsman, mill manager, explained that the shift was anything but simple.
“Flour is not an easy material to handle,” he said. “There are issues of dust residue and compaction, getting rid of the air within the package. To get volume, you need to remove air in order to fill it. There was a lot of engineering around getting the air out and the flour in.”
Mr. Huelsman estimated 70% of the mill’s output is shipped bulk with the balance in packages of 25-lb or 50-lb bags.
Mr. Veal noted that sustainability benefits of the shift to poly include the ability to bring in twice as many bags per load into the mill than was the case with paper bags. The new bags are delivered in giant rolls rather than being stacked on pallets.
“The material has to be breathable, but you have to keep flour from leaking,” he said. “You have to be sure condensation does not form.”
Also part of the packaging system is a palletizer supplied by Packaging Specialists, Inc., Plumas Lake, Calif.
At Oakland and across all of ConAgra Mills’ facilities, an integrated pest management approach toward sanitation is used with general fumigation essentially eliminated from the company’s tool box.
Examples of steps taken by the company at Oakland to enhance sanitation include the installation of structural steel at 45 degree angles to lessen harborage and the hanging of equipment whenever practical. Spouting features multiple inspection points to allow easier cleaning.
Even beyond procedures that clearly enhance sanitation, Mr. Allen said ConAgra Mills insists that its mills be maintained through an approach that goes one or even several steps further.
“We talk about ‘pristine 24-7,’” Mr. Allen said. “We want the mills to be ready at any point in time with the idea that a customer could walk through the door.”
An example of the above-and-beyond steps the company takes is the use of special aviation wax used to help keep equipment clean, Mr. Allen said. The key, he said, is to be sure the equipment is waxed as it goes in.
“If you had a $100,000 car you’d wax it,” he said. “You need to wax your $100,000 rollstand.”
Mr. Higgins added, “It helps prevent buildup of residue of grain dust or flour, but more generally it provides good ownership.”
The cleaning house for the new A mill is situated on three floors rather than as many as five in other mills. Mr. Allen said this was accomplished by beginning the cleaning process within the adjacent grain elevator. New equipment in the cleaning house includes two Bühler MTRB separator classifiers and two MVSQ aspirators.
Bulk storage at Oakland was not expanded as part of the modernization (it remains 27,000 cwts), but the loadout systems were upgraded.
In terms of automation, handheld technology has been deployed to replace push button systems that had been utilized. The new system allows operatives to connect to the control system from wherever they are in the mill.
Mr. Allen said when problems come up the handhelds are useful for lock, tag and try processes used to safely shut down equipment, signaling the motor control center to do so.
“You can go up to the piece of equipment and hit ‘try’ and see whether the equipment starts,” he said. “It helps ensure that the operative has accurately identified the source of a problem right there, rather than going into the control room.”
The handheld technology also helps with power management challenges that allow ConAgra Mills to keep a lid on costs at the mill. While minimizing the number of startups and shutdowns at mills was a principal objective of operative millers in the past, Mr. Allen said two key factors diminish that importance at Oakland.
“Pacific Gas and Electric has power issues — blackouts, brownouts,” he said. “They bid out industrial downtime on high demand days. On any given day, the weather in Oakland may be cool, but Modesto (80 miles away) may be very hot. Matt receives an e-mail about a possible shutdown. Matt will make a bid. Jess has the ability to determine what part of the complex is shut down to avoid causing disruptions for customers. P.G.E. will send a signal to the mill and shut down the A mill, the B mill or loadout. It goes down in a controlled manner.
“With automation, startups are not as expensive as you may think, and there are rebates from cooperating with P.G.E., which helps keep our costs under control. At a traditional flour mill where you need to run around and hit every button, get the line shaft going and then engage the rollstands. It may take 45 minutes to an hour to start up.”
Mr. Higgins added, “Here, it is three minutes on the A side. Bringing A up or down doesn’t cause headaches. The new systems also help eliminate the previous problem that you didn’t have all the control points. You didn’t know if you had a choke.”
The mill is designed to run lights out but generally has no less than two employees on hand. Overall, there are approximately 40 employees at the mill.
While certain new technologies are firmly established at the ConAgra Mills Oakland mill and through much of the industry, others are still evolving. For example, LED lighting has been installed through the mill, replacing 175 metal halide bulbs with 30 watt LEDs.
“We’re still experimenting,” Mr. Higgins said. “Lighting is really changing fast. It’s a critical point. When I’m slicking a flour stream, I don’t want yellow light.”
The B mill is a whole wheat swing mill in a technology that brings all the components of the flour back together at the end of the milling process.
“The San Francisco area overindexes in whole wheat demand versus the entire state of California, and the state overindexes versus the entire United States,” Mr. Veal said. “It is a very good market for whole wheat flour.”
Within a large, rapidly growing state with plenty of flour milling capacity, the Oakland facility of ConAgra Mills is positioned as a community mill, Mr. Huelsman said.
“The vast majority of the flour we mill here is shipped within a 400-mile radius,” he said. “Growing with our customers is a key. They are growing, and we want to be part of it.”
Together with the state’s large size and rapid growth come significant challenges for companies looking to build or modernize industrial buildings in California.
ConAgra Mills is no stranger to such challenges. In the late 1990s, the company tried for an extended period and eventually gave up on an effort to build a new flour mill in Fullerton, just outside of Anaheim. In the end, ConAgra acquired a Capitol Milling Co. flour mill, which the latter company had just built in Colton, about 50 miles northeast of Fullerton.
In the case of the Oakland project, Mr. Allen said the effort went well but was not without challenges.
“California has higher, very unique standards,” Mr. Allen said. “It is very environmentally conscious, which lengthened the timeline. But there were things we could do while waiting on the various permits.”
Difficulties with the project were a result of a budgetary crisis hitting the state government of California even more than a restrictive regulatory environment, said Ted Korolchuk, director of milling at ConAgra Foods.
“Documents would stack up on people’s desks, and they would get to them when they could,” Mr. Allen said.
“You would go to get a permit, and the office would be closed,” Mr. Korolchuk added. “I can’t tell you how many times that happened.”
Asked about other regulatory issues associated with operating in Oakland, Mr. Allen said the mill works hard to be a good citizen even as the neighborhood around the mill shifts from a purely industrial area to a mixed use neighborhood that includes residential subdivisions not far from the mill.
“We work to be good in the community,” he said. “When there is a noise complaint, we work to resolve it. We move things or enclose them.”
Noise issues may range from blowers and reverse fans to rail car switches during the night.
Mr. Veal noted the local business community in Oakland was very supportive of ConAgra Mills’ plans to expand the mill. Jean Quan, the mayor of Oakland, has been part of the positive response, he said.
“The mayor referred to the mill as an Oakland ‘Hall of Fame’ institution,” he said. “She participated in the ribbon cutting ceremony.”
Oakland, the nation’s 47th largest city, has made great progress toward reducing blight (and crime) in a community that has struggled for many years, Mr. Huelsman said.
The National Venture Capital Association recently named Oakland one of the top cities in the country for v.c. startups.
“It used to be that when someone transferred here, the first warning was — ‘Live anywhere in the area other than Oakland,’” Mr. Huelsman said. “My wife and I moved into Oakland a year ago, and we love it.”
“More generally, the Bay Area is a leading culinary center,” Mr. Veal said. “There is a very diverse culture, and our flour goes into a wide range of products — from wontons to tortillas. It also goes into Boudin, which is the gold standard for sourdough bread. They use our flour exclusively. San Francisco is a food centric city.”
Together with its wide ranging base of end uses, flour from the Oakland mill mostly will go into traditional products — bread and buns baked in the San Francisco/Oakland areas as well as Sacramento, Stockton, Sonoma/Napa and San Luis Obispo.
In addition to shipping locally, the Oakland mill sources a significant proportion of its wheat from the Golden State.
“We love California wheat,” Mr. Huelsman said. “It has great milling characteristics and great baking characteristics.”
Outbound shipments represent another area in which the ConAgra Mills Oakland facility is focusing on sustainability. Partnering with Carry Transit, ConAgra Mills has converted its fleet of bulk trucks to high efficiency, low emission diesel engines. Currently, the fleet includes 18 trailers and 8 tractors.
Another energy saving addition within the mill is an air monitoring compressor unit that tracks the amount of air being consumed and loads the compressors accordingly.
Mr. Allen and his colleagues said many smaller steps have been taken with an eye toward food safety. For example, within the A mill, no equipment at all is made from wood.
“The flow is 100% wood free, meaning there is no wood in the sifters or frames or dusters,” Mr. Allen said. “We’re in the brand protection business, something that is evolving in different areas. We supply many $100 million brands, and they have high standards that we’re proud to uphold.”