OSHKOSH, Wis. — For laundries looking to upgrade wash equipment, a continuous batch washing system (CBW®), also called a tunnel washer, might be an attractive option. But how is a tunnel system different from open-pocket washers, and how can a company’s operations benefit from this technology?
In Making Sense of the Tunnel, a recent webinar hosted by the Association for Linen Management (ALM), Seth Willer, national sales manager for Girbau Industrial, discussed the technology behind these systems and the advantages they can have over other systems in certain situations.
Willer also addressed the main driver for many companies looking to upgrade to tunnel washing systems: skyrocketing labor costs.
“I promise you the minimum wage will go up and I promise you labor will get more expensive if you choose to operate your laundry in the U.S.,” he says.
Willer also points to the historical trend of replacing labor with technology.
“Technology is just increasing and increasing and the laundry business is no different,” Willer comments. “We’ve always had new technology emerging.”
FEATURES
Willer listed a number of features that are typically associated with tunnel washing systems: wash flow meters; auto-level drain valves; automatic chemical injection; automatic steam injection; computer controlled operation; on-board water reuse systems; and drain water heat recovery.
The method of water removal is another key element of a tunnel washer system. Willer says there are two main ways to extract water after washing: a press extractor or a centrifugal extractor. A press extractor uses a large hydraulic cylinder to literally squeeze the water out of the linen.
“It’s a lot like stepping on a sponge,” he says.
A centrifugal extractor, on the other hand, spins at 300 G-force, or 1,000 rpm, to extract the water.
Willer says the key difference between the two types of extractors is cycle time, with a press extractor getting the job done in 90 seconds or less, and a centrifugal extractor taking roughly 2-3 minutes. After extraction, a shuttle transfer conveyor transports the laundry to the dryers.
ADVANTAGES
“The two biggest advantages are labor and energy efficiency,” says Willer. He compares the production performance of a tunnel washer system to a split-pocket, side-load washer, which relies on manual loading of linen into the washer.
With a split-pocket washer, an operator can typically process anywhere from 250 to 400 pounds of laundry per hour, Willer says, but thanks to automation, a tunnel system has a pounds-per-operator-hour rate of 1,500 to 3,000.
“If you talk to operators that have switched from open-pocket to tunnel washing systems, the labor savings are astronomical,” Willer says, adding that the payroll costs for washrooms using a side-pocket washer can be as much as four times higher than those using a tunnel system.
There’s potential for significant water savings as well, Willer says, because of the way that a tunnel reuses water for various cycles.
“Your water comes into where your linen is going to be the cleanest. It comes in your final rinse,” Willer explains. Then the water flows “backwards” from later modules to earlier ones in the sequence. With the help of storage tanks, water that is still fairly clean can be pumped to other parts of the system and used in the pre-wash or wash cycles.
A tunnel system will use anywhere from 400 to 1,200 pounds of fresh water per 1,000 pounds of linen, according to Willer, while an open-pocket washer might require 1,800 to 3,000 gallons for the same amount.
“That’s a massive savings, especially if you’re in an area where water is scarce,” he says.
Operating with a tunnel system can also result in hot-water and detergent savings, and it also allows for thermo-recovery options, according to Willer.
IS A TUNNEL SYSTEM RIGHT FOR YOUR OPERATION?
With any serious investment comes serious considerations, and Willer urges those looking into acquiring a tunnel system to take several factors into account.
For one, how tall is the facility’s ceiling? Tunnel systems need a minimum 12-foot ceiling clearance for installation, though 14 feet is preferable, he says. And a plan for redundancy is also important. What will happen if a tunnel washer goes down?
The goods that will go through the system should be considered carefully, since upping production could mean bottlenecking in the flatwork area. Also, load type should not be overlooked.
“If you have water from a load of red tablecloths, you’re not going to be able to use that bath to wash white sheets,” Willer says. “So if you have small specialty loads, a tunnel washer or CBW® might not be right for you.”
Finally, consider the capital it would take to purchase such a large, complex piece of equipment.
“It’s a big piece of machinery, and it’s not something that you can just go out and write a check for,” Willer says. “It’s a big investment.”
He advises that companies do plenty of research before making a purchase, and be sure to benchmark production and decide on an acceptable return period for the investment.
“Find a dependable vendor. Visit their references,” he says. “I cannot stress that enough.”
Have a question or comment? E-mail our editor Matt Poe at [email protected].