Before the cap and gown: The capstone

Resource,  Feb 2003  

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How much can you learn in four years? Take a look...

These capstone projects are just a sampling of the types of problems senior students are capable of solving.

Screen designed to fitter soybean flakes

The South Dakota Soybean Processors plant at Volga may be running more smoothly today thanks to three agricultural systems technology majors at South Dakota State University (SDSU).

Travis Arends, Beau Wisness, and Justin Van Veen, all seniors at SDSU, say their capstone project was a chance to put their textbook knowledge to use in a real workplace.

Van Kelley, head of SDSU's Department of Agricultural and Biosystems Engineering, says it is common practice for students in his design management experience course to tackle actual problems from industry.

As it turns out, the soybean-- crushing plant at Volga had one -- design a screen to filter soybean flakes from the soybean oil with the capability to run 2,271 liters (600 gallons) a minute, year round, without plugging. The plant had experienced problems with flakes gradually blocking the flow of the oil/hexane mixture in the distillation columns and occasionally had to shut down to clean them out.

John Prohaska, a graduate of SDSU's Ag and Biosystems Engineering Department, worked with the SDSU students to let them know what the company needed.

"The company basically said, here is a problem, go fix it," says Arends, who works part-time at the plant while continuing his studies.

The screen had to have absolutely no moving or electric parts to avoid any chance of sparks. That is because the Volga plant, in its process of removing oil from the soybeans, uses a highly flammable chemical called hexane.

South Dakota Soybean Processors also gave a mandatory deadline. The screen had to be ready to install by the first week of May, when the plant was shut down for maintenance. Otherwise, it would have to wait another year.

"Procrastination wasn't an option," Wisness says.

"It was a good experience," Van Veen says. "We started with nothing, basically, and just began brainstorming about possible solutions."

He adds that there was a lot of hands-on work involved, too. Arends, Van Veen, and Wisness built their own test apparatus and took it to the plant to experiment with various design features.

"They had to come up with design parameters: what size screen to use, the flow it could handle, the angle at which it should be placed," Kelley says. "And they had to be pretty close to right You only get one stab at it."

Arends adds that the three talked to plant personnel for additional input about design features that could make it easier to service and maintain the screen.

Once they had tested a model, they drew up plans for the actual tent screen that would be used in the plant. They sent those plans to a fabricator in Sioux City, Iowa who built the screen to required specifications. Thanks, in part, to a large investment of time outside of class, the screen was designed and ready to be installed in May, just as the company ordered.

"It's on line and working very well," says Prohaska, the engineering coordinator for the company. "We use it every day to help keep our process working efficiently."

Prohaska says this was at least the fourth year South Dakota Soybean Processors has worked with Kelley's students. In past years the students have helped design meal sifters, a new conveyance system, and a new storage system.

"It's a great working relationship for both SDSU and the company," Prohaska says. "We get dividends in the long term. If we can capture the interest of just one student, it will benefit our entire industry."

Food waste composted from residence halls

ASAE member Nathan Rice and Kerry Trambaugh developed a plan for collecting and transporting food waste from residence halls for their senior capstone project at Purdue University.

Rice and Trambaugh's objective was to estimate the volume of waste produced from serving more than 3 million meals yearly and developing a plan for collecting and transporting the waste from Purdue's residence halls to the compost site.

Organic food waste, when combined and composted with other feedstocks such as leaves, woodchips, and manure, makes a great soil additive. Composting these wastes also reduces landfill fees and could possibly produce a marketable product.

Data was collected to quantify the amount of food waste generated at each dining hall. The information gathered included volume, weight, and density samples. The average density after pulping was determined to be 240 kilograms per cubic meter (15 pounds per cubic foot) of waste. The average moisture content was 76 percent. A formula was developed to predict the volume of waste based on the number of meals served.

The analyses showed that the volume of waste from the residence halls varied from about 11 to 100 liters (0.4 to 3.5 cubic feet) per day. Annually, the residence halls at Purdue University are expected to generate slightly more than 145 metric tons (160 tons) of organic food waste. If this much waste were diverted from the local landfill, approximately $5,600 would be saved.