The benefits of industrial filter recycling for metal manufacturers
Oct 22, 2023
Henk Hulshof / iStock / Getty Images Plus
Metal fabricators likely don’t think about saving the world on a regular basis, but they do like to save money. If they can do the latter and the former is a byproduct, then that sounds like what business consultants call a “win-win” scenario for both the fabricator and the earth.
Mike Wright, CEO, Wisdom Environmental Inc., Greenfield, Ind., sees opportunities in industrial recycling where others see headaches. He has spent the last several years of his life running a business that recycles manufacturing byproducts, helping companies get the most of their investments and keeping these byproducts out of landfills.
“We’re very big into abrasives recycling—spent steel shot, spent steel shot dust, and basically any type of surface treatment byproduct that’s generated,” Wright said.
Large, used steel shot that is collected from manufacturers is cleaned, reprocessed, and sold back into industry as smaller-sized abrasive shot. It keeps being recycled until it turns to dust.
At that point, the dust is recycled into concrete products, made at one of Wright’s other businesses. Wisdom SteelCrete recycles the steel shot dust into things like security barriers, retaining wall blocks, and counterweights.
Then about five years ago, Wright got a call from a customer.
“The customer said, ‘Hey! You’re recycling my dust and recycling my shot. What are you going to do with my filters?’” Wright recalled. “Well, I said, ‘What’s going on in the filter world?’ And it turns out that there was not recycling options there.”
Presented with the challenge, Wright began investigating what could help him offer industrial filter recycling to manufacturers. He found an answer with a machine used to clean diesel air filters on trucks.
The technology was designed to extend the life of expensive diesel filters found on industrial trucks, such as the million-dollar vehicles used in mining. Such dirty and dusty environments can quickly clog up a filter, and just throwing those filters away can get very expensive.
Wright discovered that the machines could accommodate the very familiar circular and oval filters that are found in thousands of industrial fume management systems across the U.S. Wisdom Filter Clean now has two of the machines. They accommodate filters that are 42 in. tall or smaller and have a minimum 3.5-in.-dia. middle opening.
Wisdom Filter Clean is proving that a used filter from a dust collection system can be cleaned and reused, sometimes up to 10 times. Images: Wisdom Filter Clean
The machines use air streams to clean both the inside and outside of the filters. To provide the customer with an idea of just how effective the cleaning was, the filters are physically inspected for potential damage before they are placed in the machine, and a flowmeter is used to determine the filter’s overall ability to capture dust. When the filter is cleaned and removed from the machinery, it’s checked again with the flowmeter to provide a performance metric, a number that gives the customer an indication of where that filter is in its lifecycle.
“We can then track the life and performance of that filter,” he said. “It can get a little bit technical, but you just need to know that eventually the filter reaches a point where they’re not able to be cleaned in a way that will perform like a new filter.”
This is where the company’s business model expands just beyond offering a cleaning service. When Wisdom Filter Clean receives 10 filters from a customer, for example, a technician might find that two of the filters are no longer capable of operating at original OEM specifications. The company notifies the customer that they need to purchase two more filters to replace the unusable ones. Instead of just ordering new filters every time they are pulled from the fume collection equipment, in this hypothetical case, the customer only has to purchase two new ones.
“Believe it or not, we’ve done studies on filter failures, and the rate of filter failures is less than 2% of the filters that we receive,” Wright said. “And of that 2%, it’s usually physical damage that is the reason the filters fail.”
Wright said industrial filters might run anywhere from $90 to $400. Companies that purchase a lot of filters might get price discounts that are unavailable to the shop only buying a handful of filters at a time.
With recycling, an industrial filter can be reused from two to 10 times. The type of material being filtered obviously affects a filter’s ability to be reused. Welding and laser and plasma cutting dust are considered not to be too aggressive when it comes to affecting filter life.
“The cost of filters keeps going up every single year. It’s a real cost,” Wright said. “But not a lot of people are thinking about cleaning filters. They’ve always seen them as disposable items, like coffee cups. You just throw it away.”
When it comes to pricing, Wright said Wisdom Filter Clean generally charges 50% of what a company was paying for a new filter. The manufacturer has to ship the filters to Wisdom Filter Clean, who then cleans, tests, packages, and sends the filters back. The service usually takes about two weeks from receiving the filters to sending them back to the customer, Wright said.
All sorts of filter types are candidates for cleaning and reuse, according to Wright. That includes basic cotton filter media, web or nanofiber material, and spun bond media.
“We have found that the spun bond material can be cleaned many times. It’s just a tougher filter,” Wright said.
This type of dust collection system is common in welding and metal fabrication shops across the U.S. That’s a lot of industrial filters that are simply thrown away and destined for a landfill. Cleaning those filters can keep them out of landfills and more money in the pockets of metal fabricators, who might be able to reduce the number of filters they buy.
Many customers that have been using the company’s filter cleaning service have worked the service into their own maintenance programs. Either after testing air flow and finding poor test results or just sending the filters out because a specific time period has passed, maintenance personnel send the filters out to be cleaned and replace them with a second set that they have on hand. That way the customers have a fully functioning duct collection system even when the filters are out to be cleaned.
So what happens to the filters when they aren’t usable any longer? They are recycled, like everything else.
The filters usually have a metal cap and a metal bottom. The cage in which the filter material sits also is metal.
“We actually compress those filters in a machine,” Wright said. “That crushes it down and we send it to a local scrapyard. They melt it down, and the metal is used for other things. The paper media burns off in the process.”
One more filter diverted from the landfill.