When Missy Morrison, plant manager at Star Milling says, “we want to avoid injury at all costs,” it’s a legitimate objective, not a safety slogan.
Morrison and maintenance manager, Keith Williams, attend safety seminars throughout the year and keep up on OSHA news. “We are in a high risk industry,” says Williams. “Many people don’t understand that grain milling is high risk. It’s an extremely flammable industry.”
Star Milling, in Perris, California, brings in raw grains and other ingredients to produce wholesome feed for a wide variety of animals. In addition to producing its feed labels, which include “Integrity,” “Kelley’s,” “Ace Hi” and “Ultra Balance,” the company does private-label services and delivers its feed in bulk tankers to farms. Operating based on core operating values and principles for more than 40 years, the feed mill is still family-owned and operated. It’s said to be the largest in southern California.
Facility equipment includes an extruder, two pellet mills, a grain cleaner, roller mills for making rolled barley grains, a mixer for pigeon and wild bird feed, a fully automated bagging system that uses a robot to palletize sacks and a small bagging line for small packaging flexibility. To continue growing by making best use of capacity, new electrical and computer systems facilitate increased facility automation.
Setting the stage
With increasing production, manual cleaning methods were becoming cumbersome. “As plant manager, the vision for me is a clean mill. I want to look up high and not see any webs or dust,” says Morrison. “I feel that a clean environment makes it easier to be at work and that creates a happier, more productive team.”
Knowing that combustible dust is one of OSHA’s increasingly hot topics, “especially with feed mills,” says Williams, he and Morrison researched alternatives to manual cleaning methods, like sweeping or compressed-air use.
“Compressed-air use is something to get away from,” says Williams, “it just blows the dust around into hard-to-reach areas.”
Although vacuum cleaners are the preferred method of removing fugitive combustible dust, the mill had previously used an agricultural vacuum which Williams says, “is great on the farm, but not for an application like ours. We tried to use it for years but it just wasn’t working.”
Another alternative would be a central vacuum system, which Williams says, “would be expensive to set up and require more piping, which actually would increase the areas where dust could settle. This is a big facility, and getting a vacuum that can pull from one end to the other would require something huge and the cost would be crazy. So we had to figure out how to combat an expensive problem cost-effectively.”
Typically, central vacuum systems require a bag house with either a chemical-suppression system or an explosion-venting system to meet NFPA and OSHA standards.
Both Williams and Morrison researched products that met OSHA requirements for a combustible dust vacuum.
Where we landed
Celebrating 60 years of intrinsically safe vacuum cleaners for production lines and other dust-intensive areas, Belleville, NJ-based VAC-U-MAX, the pioneer of heavy-duty industrial vacuum cleaning systems, has field-proven equipment that creates a safer and cleaner environment for both capital equipment and employees.
After researching available options, Morrison set up meetings with a European industrial vacuum cleaner company, as well as with Air Cleaning Technology (ACT), which represents Belleville, New Jersey-based VAC-U-MAX, a provider of heavy-duty industrial vacuum cleaning systems. In the air cleaning business for 37 years, Santa Ana, California-based ACT is a full-service pollution control company.
During the initial discussion between ACT Sales Engineer Randy O’Halloran and Star Milling, the option of dust collection equipment was considered. However, during a walk-through, when O’Halloran saw the problem areas in the mill, including rafters, beams and pits, coupled with a desire to quickly clean spills, the picture became clearer. “When it comes to that type of application, it’s not just collecting fine dust, it’s collecting a little bit of everything and it naturally lead itself to be a vacuum cleaning application.”
After receiving quotes from both companies, Williams used spreadsheets to ensure they compared apples to apples. They even spelled out every type of hose and connection involved; “everything side by side,” both Williams and Morrison say in chorus.
At the end of the day, the price points were pretty close.
When asked, then, what the tipping factor in making a choice, Williams says two points come readily to mind. “The VAC-U-MAX 1020 has much higher suction and that made me happy; and, the European brand was metric and I prefer to keep everything in the shop standard if I can.”
Reasons for this
The cause for the higher suction on the USA model is a result of the positive displacement pump (PD pump) vacuum producer. PD pumps generate high vacuum and excellent airflow so they have the ability to pull massive amounts of material over distances. The 15 horsepower model that the feed mill employs can move 10,000 pounds of powder in an hour from 30 feet away, if needed.
Regenerative blowers can be a vacuum source in central vacuum systems that have the airflow but not the simultaneous vacuum. Regenerative blowers seem appealing because they show significant airflow for a given horsepower, but they don’t generate enough vacuum to move material over distances in tubing; when vacuum pressure goes up, i.e., when the job gets tough, performance is lost.
Williams says, “I like being able to do whatever I want with one vacuum. It is a dual-purpose machine that maximizes ROI. It is a cost-effective alternative to what could have been very expensive.”
For its customers, VAC-U-MAX says, creating a breakaway vacuum system with several smaller tubing networks is often a good answer. For instance, if a user is working in a 100 x 200 square foot area and there are two more areas in another building, individual tubing networks are created and the 1020 broken away from one tubing network and rolled to the next network; and so on and so forth.
A stationary central vacuum system to suit Star Milling’s plant layout would be large and require an explosion-protection system. That would have meant an outdoor installation, leading to other challenges such as construction and air permits. The breakaway system avoids costs and delays, has the convenience of a multi-inlet central vac, with the flexibility of a portable vacuum.
Star Milling installed several fixed-tubing networks itself. “I have two fabricators, on-staff electricians and programmers — we only bring in contractors for very large jobs. Randy from ACT told me how to do it, sent me diagrams, and told me where to get the pipe and that was that.”
Performance that followed
Once the system was in place, supervisors and operators and operators were taught how to use the machine. “It’s pretty much plug and play, but the suction is powerful and we wanted to be sure everyone was using the vacuum safely,” says Williams.
“We did have a bit of a learning curve with the intercept drum before we got it to the mill,” he says. “We kept collapsing drums and turning them into perfect triangles. I had to call ACT to make sure we were using the system correctly and find out why it was out-performing what we talked about.” Intercept drums need to be a minimum of 16-gauge steel with a rolled-top rim, two reinforcing chines and no dents or dings.
VAC-U-MAX sells drums, but since Star Milling had a wealth of drums on site, they decided to use one they already had and Williams just had to find the right one.
Cleaning the upper area of the Pellet Mill was one of Morrison’s first projects. “Before we purchased the vacuum, we used to clean that area every three months and it took one person all day to clean it,” she says.
It was difficult because elevated and had tough-to-reach places, and it was messy, knocking everything to ground level and then cleaning from there, which “of course, created dust that landed where it landed,” she says.
“With what we have now, all the dust and cobwebs are sucked into the vacuum system,” says Morrison. “Now we are working on a detailed cleaning of the entire facility, which if you can imagine, would be like cleaning every inch of a large wooden roller coaster. There are lots of high rafters, pipes, ledges, beams and equipment.”
A three worker crew works eight hours over the weekends to do it. “After we get there, we’ll have a better understanding if we’ll need someone full-time to vacuum or if the operators can do it during their shift rotating days for different areas,” says Morrison.
Confined spaces consideration
The elevator pits are confined spaces. Dust accumulates there “because it’s hidden and you have to go looking for it,” she says. “Now we have vacuum extension tubes that give us the ability to clean there without anyone entering the confined space, which is a big deal for us. Every time someone enters the confined space you should have a three-person team monitor the air,” says Morrison.
And, Williams adds, “The extensions don’t reduce vacuum suction.”
Before Morrison and Williams scheduled cleaning the pits, operators began doing it on their own — getting the vacuum from the shop and bringing it to their area. The unit is designed for one-person maneuverability with 14-inch diameter wheels, but Star Milling chooses to move the vacuum from area to area with a forklift.
Because the 1020 filter separator and collector are less than 8 cubic feet, it does not need an explosion vent to use it in Class II, Div 1 & 2 areas, per NFPA standards and OSHA regulations. Even so, Williams has set up the tubing network so the machine operates in a non-dusty environment. “I just prefer it that way,” he says.
To learn more about VAC-U-MAX vacuum cleaning solutions, or combustible dust vacuums, write to them at 69 William Street, Belleville, NJ 07109; call 1-800-VAC-U-MAX (800) 822-8629 or (973) 759-4600; e-mail firstname.lastname@example.org; or visit their website.