MOORHEAD, Minn. - American Crystal Sugar Co. is completing a $44 million sugar dome warehouse near Chicago - a new sales and marketing tool ready just in time for the holidays.
American Crystal is building and will own the transload facility, with its 160-foot-tall, 1.3-million-hundredweight dome. It is designed to bring sugar closer to the customer in the greater Chicago market, cutting costs and time.
United Sugars Corp. will lease it from American Crystal and will maintain it. The marketing and sales company held a grand opening for customers on Nov. 16, and the first loads are staged and expected to start running through the facility in mid-December, officials say.
Based in Bloomington, Minn., United Sugars is the biggest sugar marketing company in the country. It sells sugar for American Crystal of Moorhead, Minn.; Minn-Dak Farmers Cooperative of Wahpeton, N.D.; and U.S. Sugar Corp. of Clewiston, Fla.
Sugar is one of the signature crops of the Red River Valley, boasting what is now about a $5 billion economic impact in the region. It is the quintessential value-added enterprise, where farmers own processing facilities.
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American Crystal is the largest beet sugar producer in the U.S., and its cane-producing marketing partner, U.S. Sugar Corp., is the largest producer of sugar cane in the U.S. It is owned by its employees and charitable foundations.
Matt Wineinger, president and CEO of United Sugars, says Chicago is by far the largest distribution point for sugar coming out of the Red River Valley. "It's going to account for 20 to 25 percent of the sugar we ship from this area," he says.
Cutting risk
The intent is to avoid the risk in logistics. In 2014, the company had to idle three of its processing factories for two weeks because they were full and couldn't get rail service to pull the production away from the factories.
The new facility means American Crystal and its allies will be able to move sugar out of the valley, at a time when they have rail capacity and the company is full on sugar. In the past, the company has put sugar in box totes in warehouses rather than leaving it in bulk storage.
Aaron Bjerke, American Crystal's business development manager, is trained as a construction engineer. "United Sugars had been looking at this for a number of years," Bjerke says. "They had been looking for locations where BNSF would have the ability to supply a new customer with the number of cars we needed - roughly up to 24 cars a day."
The company considered various building styles, including the Weibull structures at American Crystal facilities in Hillsboro, N.D., and elsewhere. They also considered a slip-form concrete structure, familiar to farmers as grain elevators, but the dome came out on top for building and equipment costs. A set of silos would require four sets of conveyors and sweeps.
"With the dome, we have one set of screw conveyors coming to and from it, and one sweep inside."
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Track record
Domes have been built for almost 30 years around the world. Initially, they were built for non-food materials. Now, with new coating technologies, they've been able to make them for food use. This is the third sugar dome made by Dome Technology of East Idaho Falls, Idaho. The company has built similar sugar domes next to refineries in Guatemala and Hungary.
The American Crystal dome started with an AirForm - tough, multi-layered fabric form that is plastic on the outside - which takes about 30-member crew to inflate it. They stretched the material across a 185-foot-diameter base and inflated it overnight under calm winds on March 29. The AirForm includes 75,000 square feet of interior surface and weighs 25,000 pounds - or about 12.5 tons.
The crews pre-positioned rebar and a 70-ton crane inside. Construction took about six months.
First, they sprayed about 2 inches of foam for insulation around the inside of the form. Then, they started erecting rebar - one-inch diameter reinforcing steel bar - and sprayed it with a high-velocity "shootable" concrete, he says. "The amount of rebar in the project, just inside the dome, was equal to 27 truckloads," Bjerke says.
The inflators were taken off around July 4, when the concrete cured enough to hold the dome up.
The dome's concrete is about 12 inches thick at the base and about 8 inches thick at the top. Near the top there is a circle of six, 500-square-foot "explosion vents" - about the size of a two-garage car, each. In the case of an explosion, the vents would pop off.
"It's an incredibly efficient structure for load," Bjerke says.
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Highly efficient
The sugar comes into the facility in train cars and is conveyed up and across in "bridge tube." The bridge puts 75,000 pounds on the top of the dome, but it's designed to take up to 500,000 pounds.
The dome includes an air lock on the top, which prevents air from passing through the screw conveyors to the air lock below it. Everything that handles sugar has dust collection explosion suppression equipment.
The new dome has temperature sensors on the bearings, alignment switches in bucket elevators, dust collection on everything, and sodium bicarbonate (baking soda) cannons equipped with pressure sensors. "If a bucket elevator were to have a hot spot that would create a combustible dust explosion, it senses an explosion wave,"Bjerke says. "Those cannons are like fire extinguishers that shoot a baking soda-like product on to stop a chain of explosions."
The walls of the dome are equipped with heat-trace cables. "The dome has about 50 circuits of heat-trace cable embedded in the concrete of the walls to keep the walls warm, so we don't have any condensation," which makes sugar clumpy and hard, Bjerke says. The air above the sugar in the dome is conditioned to 55 percent relative humidity and cooled or heated to 70 to 80 degrees Fahrenheit.
The dome base has an access door for maintenance. The door weighs 11 tons and is opened with a forklift for maintenance, as needed.
The dome is built without foundation pilings.
"In the Red River Valley, it would be more of an issue because we have 150 feet of clay under us, while this facility had 35 to 40 feet of sand and gravel underneath it.," Bjerke says. "The dome can settle and will settle."
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A large screw conveyor lies at the bottom of the dome - 85 feet long and 5 feet tall - designed to retrieve product that doesn't naturally flow through the floor hoppers.
Ironically, American Crystal has a lot of experience in moving sugar, but has never before had to unload a bulk rail car before, Bjerke says, so customers have offered advice.
Rail-to-truck
The unload capacity is 24 rail cars of bulk sugar a day. "We'll be able to bring in 12 cars, twice a day, and unload one car per hour," Bjerke says. "We'll fill the dome in about five weeks at that unload rate, which is 650 rail cars of sugar. One specialty foods rail car holds about 2,000 hundredweight of sugar.
The unload system includes special "boots" that detach and seal off the rail car bottoms into the basement "pit" below. The pit is 35 to 40 feet deep with three-foot thick walls to keep the ground water out. They're below the water table, but have a high-capacity sump system that takes 200 gallons per minute.
Sugar comes from the bottom of a rail car. A screw conveyor takes it across a trans-load facility. Finally, the sugar goes into a bucket elevator that is 205 feet tall. From there, it drops into a screw-tube that goes through the gangway - a 12-foot diameter tube that leads to the top of the dome. Crews installed the 140,000-pound tube with a 600-ton crane.
The sugar goes through a 30-by-30 foot head house structure at the top of the dome, which includes a magnet to ensure the sugar is pure before going into storage. It is distributed into the dome with five spouts.
On the outgoing side, the transload facility handles six trucks parked inside. Two are in a pre-load condition - two are on top of the scales, and two are in an exit position. The facility has the ability to bypass the dome and take sugar from a rail car to a truck, but that would be an exception.
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Filling time
Filling time is from Nov. 1 through Feb. 28. "We will fill it and hold it at capacity - putting as much in as we take out - from February through May, when slice closes up here," Wineinger says. "We'll ship out of that facility to about zero until time when the new crop starts shipping in the fall of the following year."
"The dome can be filled and emptied multiple times a year, if necessary to feed customer demand," he says.
Bjerke says that, as a cooperative, American Crystal has done most of what it can do internally to save costs in its operations back home. The co-op also looks back to the farm level to save costs, through cooperation with grower-shareholders. This move helps the company extend efficiency toward its customers.
"How can we increase revenue? Increase customer supply and satisfaction and save some costs on the marketing and distribution side," he says. "That's really what this does."
Additionally, Bjerke says the property is organized so that they could build a second dome, if it works as well as planned.
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