Cleanliness is Quality

FROM THE APRIL ISSUE: Ignoring proper bin maintenance, such as cleaning and full material removal, reduces storage capacity and product quality.
By Tim Albrecht | March 19, 2018

Bridging, plugging, buildup, chaffing, funneling, doming, etc. They’re all common problems in grain and DDGS storage silos. Maintaining those silos is an important step in ensuring plants are getting full efficiency from their materials, says Dan Bruenderman, project manager/engineer for Mole Master Services Corp.

“What we’ve found early on, with the ethanol industry especially, is most plants basically ignored those bins at startup and went several years before they addressed the issue. Once they realized what kind of severe problem they were having, it reduced storage capacity in those bins and the product quality. They figured out they needed to maintain those bins just like any other piece of equipment they maintain.”

Mole Master specializes in cleaning of silos and equipment, also offering ancillary services such as water blasting, vacuum services, media blasting, carbon dioxide blasting and dry ice blasting, Bruenderman says. “We provide both the service and the equipment for plants to do it themselves, as well.” The company’s main service, the Big Mole System, negates the need for human entry into silos, making cleanup safer and more efficient. The Big Mole System uses a dry process, eliminating water damage to the material or facility during the service, and preventing expensive cleanup. The Big Mole System uses air to break loose hardened material stuck in bins, aerating and moving material to allow flow to the discharge point, Bruenderman says.

Mole Master breaks cleaning projects into three categories based on difficulty: low, medium and high. About 60 percent of projects fall into the medium degree of difficulty category, with the other 40 percent split evenly between low and high degrees, he says.

“There are projects that are fairly simple and straight forward, which we can just make a phone call to the customer, understand their situation and provide a solution. Other times, there is quite a bit of involvement where site visits are required so we can get a good understanding of the scope of the problem. It can be a difficult solution at times.”

According to Bruenderman, a variety of reasons dictate difficulty level, including design of the storage vessel, layout of the plant, weather conditions and material. “Moisture intrusion can turn flowable material into a solid mass,” he says. “Add in freezing or extremely hot factors and normally flowable material turns into rock hard material that may require the use of our Safe-T-Shot Co2 blasting system to break it up into chunks small enough to discharge.”

Seneca Companies Inc. has been doing a lot of bin cleaning—both grain and DDGS—recently, as a result of maintenance issues in some of the plants it services, says Chris Biellier, vice president of the environmental and waste solutions division at Seneca. “What we’re seeing with bin cleaning is either the plant’s delivery system is broken down and they have bridged corn within it, or in order to make some of the mechanical repairs, they need to get the material out of the vessel. This could be for a variety of reasons, such as materials being too dry or wet.”

The company offers spill response, scheduled and nonscheduled shutdown maintenance, and cleaning. “That maintenance includes any component of the plant that requires cleaning, water blasting, grain bin cleaning, elevator pit cleaning and dry ice blasting.”

Seneca predominately performs water blasting at plants, but services vary at some plants depending on the type of shutdown in place. “It depends on if they’re doing a full shutdown or smaller component shutdowns,” Biellier says. “We’re seeing that the industry is trying to maximize the productivity of their plants with partial shutdowns, so we may just go out and clean up evaporators only.”

The process for water blasting can vary depending on the plant and the level of the problem, but Seneca maintains a constant line of communication with the plant to fit its specific needs and timeframe, Biellier says. “We’ll go look at the particular areas a plant may want cleaned, especially if it isn’t a plant we’ve worked with before. Then we’ll work with the plant in identifying a timeline to get it done, the number of people necessary to perform the work, and whether it will be a 24-hour per day job with multiple shifts or getting as much done as they would like in a single shift. Each plant is going to be unique.”

Silo Reclaimer
Primary to keeping a silo clean is ensuring efficient removal of all materials stored inside. “In any storage vessel, distillers dried grains can get sticky and hard, and if it’s allowed to sit for a long time it can create bridging problems,” says Mike Schuster, vice president of sales at Laidig Systems Inc. Laidig offers a custom-engineered system to reclaim materials from the bottoms of silos. “Our solution is very niche. It’s called a silo reclaimer. Our reclaim device is an auger that rotates 360 degrees around the bottom of a silo. It’s installed in concrete in the bottom of the silo and the auger assists in unloading the distillers dried grains.

“We’re always trying to achieve a first-in, first-out inventory pattern where the stuff on the bottom is the first to go out.”

A track drive reclaimer is used for bins with diameters of 55 feet or larger. It’s a more robust system, Schuster says, supported around the exterior by a track that’s mounted to the concrete floor, for full support during the 360-degree swipes.

“If you don’t have a Laidig or something that’s really aggressive in the bottom of the silo to get that material out, you can have problems.”

Adherence to Maintenance
Biellier says Seneca’s cleaning services are performed routinely, as well as when incidents arise. “I would say it’s 50-50,” he says. “Some of the places we work at is routine maintenance scheduled months in advance. The other half of our customers use it on an as-needed basis, which can occur throughout the year as the plant operates. They may have a breakdown and make immediate repairs to allow them to run at optimum efficiency.”

Conversely, Bruenderman says Mole Master’s specialized bin cleaning work is done mostly on a routine basis when shutdowns are scheduled. “There’s a lot of plants that really adhere to a maintenance program with their bins now. … If they become aware there is a problem, that’s when they call us in. Kind of a ‘if it’s not broke don’t fix it’ type of attitude.

“What we found is those plants that actively manage their bins and maintain them, it becomes a less difficult project and subsequently costs a lot less to take care of.”

Author: Tim Albrecht
Associate Editor, Ethanol Producer Magazine