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Fine-tuning the Overall Drying Process (Part 1)

Effective use of technology, drying formulas

CHICAGO — Every step is important when it comes to processing linens.

But a weak drying process can impact and laundry/linen service in many ways, such as increased linen loss due to over drying, more employee handling and higher labor costs, a decrease in quality, and more.

How can an operation fine-tune its drying process?

American Laundry News contacted several equipment manufacturer representatives for their thoughts on how laundry/linen services can make their drying processes more effective and efficient.

TAKE ADVANTAGE OF, MAXIMIZE SENSING TECHNOLOGY USE

One factor most of the experts pointed to in fine-tuning the drying process is preventing over drying, and that means making use of moisture- and temperature-sensing technology.

“Quite simply, over dry prevention technology is the most important feature in tumble dryers today,” says Bill Brooks, national sales manager for UniMac. “If on-premises laundry staff isn’t utilizing this technology, the operation likely is not running at peak efficiency.”

He says the first step in removing this inefficiency is selecting a tumbler that has an extremely accurate moisture-sensing system that has a large sensing area (not just one spot) and offers constant measuring. 

“Accuracy means staff will trust that when the tumble dryer stops, it has achieved the desired dryness level,” points out Brooks. “However, operations that want to ensure staff isn’t overriding the technology or performing their own ‘checks’ by opening the door frequently, will want a laundry management system.” 

“By having employees manually open the dryer and feel the load to determine if it is dry, it often leads to over drying of the linen,” adds Keith Ware, vice president of sales for Lavatec Laundry Technology. “Most linen damage will occur in the last 10% of a dry cycle. If the linen is over dried, it leads to fiber damage, rough linen and the potential to scorch the product.”

Kevin Hietpas, director of sales for Dexter Laundry agrees that moisture detection is an underused technology, which can result in higher operating costs for a laundry service, beyond damaged goods. He says that with roughly 50% of the cost of running a laundry operation being of labor, the time saved with moisture-detecting dryers can add up to big savings in labor.  

“For example, saving only eight minutes per load in dry time can save almost $5,000 a year in labor cost,” he says. “In just one year, that savings is many times the cost of upgrading from a non-moisture detecting dryer. In addition to the time savings, moisture-detecting dryers will also save wear and tear on linens, as well as save on utility costs.”

Most of today’s dryers include microprocessors that monitor multiple sensors and allow the user to adjust parameters such as temperature and dryness level, shares Joe Carrita, customer relations manager for ADC representing Whirlpool Corp. Commercial Laundry.

“Taking advantage of the offered computer technology may allow properties to effectively create cycles that are specific to the loads they are processing,” he says. “Doing so, may help prevent over drying, help prevent utility wastes and help against increased machine wear.”  

TAKE ADVANTAGE OF DRYING PROGRAMS/FORMULAS

Gabriel Camacho, president of Consolidated Laundry Machinery (CLM), sees many operators not taking advantage of the different types of drying programs offered on dryers. 

“The usual setup is drying by time and temperature, but many do not take advantage of which temperature the program uses to control, i.e., inlet or outlet,” he says. “Normal operators use outlet temperatures for the set point, which works for most cases, as it’s the temperature of the air after the goods. 

“However, when maximum dry capacity (max load) is required or sensitive materials are being dried, inlet temperature set points should be used. This will limit the temperature before the goods, giving your max load or sensitive products time to reach temperature without being exposed to excessively high temperatures during ramp up.”

Steve Wilbur, director of engineering and product development for G.A. Braun Inc., says fine-tuning a dryer formula for each good’s type is the only way to ensure goods are not being over dried or under dried. 

“The use of differential temperature is the best way to dial-in each formula to leave just enough moisture so the goods do not become completely dried out as they travel through the remaining processes prior to being shipped to the customers,” he says. “If product is being conditioned prior to going to the ironers in finishing, the goods can be checked to ensure they have the proper moisture content left.”

Darrell Redler, marketing director-systems for Pellerin Milnor Corp., says drying formulas need to be evaluated for optimal performance—is the laundry getting as many loads per hour as it can without sacrificing quality? 

“With the dryers in good working order, further refinements to the drying formulas may help improve performance,” he says. “With few exceptions (such as timed formulas for conditioning only), dryers are usually programmed to leverage the particular technology used by the manufacturer to determine when drying is completed so that the cool-down step can begin.” 

“It should be ensured that the dryer precisely stops the drying process at the optimum linen temperature, depending on the type of laundry, and automatically cools down to the optimum temperature for the laundry before the finishing process,” Thad Southwick, project manager for VEGA Systems USA, shares.

Redler goes on to says that it’s important to note that in dryer systems programming changes affect all dryers. Start with all dryers on a level playing field, and implement changes one step at a time. 

Bob Fesmire, president of Ellis Corp., recommends experimenting with each dryer.

“For example, if your dryers are in a line, they will or can have slightly different airflow and/or slightly different pressure,” he shares. “Really analyze and experiment if you have the capability, such as changing basket speed, blower speed, inlet temperature if you can do it on your dryer. Some dryers have automatic algorithms that can help dial these in for you.” 

It’s also important to have the right number of dryers, according to Ware. 

“We often see customers wanting to purchase a large tunnel system but skimp on the number of dryers,” he says. “Accurately projecting your dryer capacity is important to a well-designed system.”

Redler says the ultimate goal is to understand what normal performance looks like in terms of loads per hour and moisture content requirements so that if something goes wrong, the laundry can, hopefully, eliminate programming as the culprit. 

“Normalize, optimize, then set expectations for standard performance,” he says.

Once the drying formulas are set, Redler suggests that they should be left alone, unless a situation arises that wasn’t initially considered, such as the best way to treat partial loads or unusually small loads or even seasonal differences in dryer performance. 

“The best advice then is to be as familiar as possible with the troubleshooting technology in the dryer or system controls and to avoid programming changes to fix human error or some other mechanical issue with the dryer,” he shares.

Check back Thursday to learn about proper loads, washer function and maintenance.