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Drying their best

Regular upkeep and frequent inspections can protect owners from debilitating dryer malfunctions.

July 02, 2012
KEYWORDS dryers / ducts / RO / spot-free
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If early carwash cave paintings existed, there’s little doubt that the portraits would include primitive car-pulling chains and scads of employees donned in soapy mitts. From the dawn of the first tunnels to the high noon of today, the carwash industry has made many cosmic leaps forward. In fact, modern computer-controlled tunnels and in-bay automatics would appear to be sci-fi fantasy to the carwashers of a few decades back.

This rapid evolution of carwash tunnels and bays has pushed many locations to new heights of automation — today an entire express tunnel can be operated by a single employee. And, when thinking about all of the carwash advancements, functional dryers may be one of the most financially beneficial. Drying a vehicle was once a task that took three or four scurrying employees a couple of minutes to finish. Now the service is completed on-line in just seconds by different types of mechanized units.

Due to the importance of dryers, owners and operators must always be “on-call” when it comes to inspecting dryers and repairing any mechanical problems. Put off procrastinating until tomorrow, and follow the steps below to keep your dryers completely clean and fully functional.

First things first

First, an operator should develop an inspection check list so little problems can be found before they become big problems, according to Archie Johnson, owner of The Dryer Pros. The best place to start a list is with the dryer’s manufacturer. A representative can help create a preventative maintenance program aimed at extending the maximum performance of the system. “Remember, dryers are a major investment, so make sure a preventative maintenance program is in place and followed regularly,” he suggested.

Safety is also an important concern with dryer inspections. Some problems, particularly with the air producers, should be addressed immediately after discovery for safety reasons, Johnson noted.

Employees should remember safety as part of the inspection process as well. “Prior to inspecting any drying system, lockout all power to ensure the safety of the inspector,” J. R. Klemmer, vice president and general manager of Proto-Vest Inc. said.

Minding the motors

Although motors are one of the key components of any dryer system, they usually receive little or no preventative maintenance. That’s mainly because their moving parts are inside and out of view. Johnson stated that motors usually do not get much attention until they stop running due to their circuit breaker tripping. But, by that point, serious and sometimes expensive repairs are needed. Below are a few suggestions to help prevent this problem.

Check the temperature: An owner or employee can feel the temperature of the motor simply by placing his or her hand on it. Johnson said it should be warm to the touch but not excessively hot.

Also, a regular visual inspection should be done on the motor’s cooling fan and cover. This is an easy way to ensure there are no blockages that would cause poor airflow over the cooling fins, Klemmer revealed.

Listen for vibration/noise: If an unusual noise or vibration is felt in the motor it should be shut down and carefully inspected to properly diagnose the cause. Klemmer said there can be a number of causes for these vibrations, such as:

  • Bearing failure;
  • Impellor balance issues;
  • Dirt and wax buildup; and
  • Foreign material attached to an impellor blade.

Especially listen for unusual noises when the motor is shut down and it comes to a stop. Grinding or squeaking sounds usually indicate that the bearings need to be replaced soon to avoid more serious problems, Johnson explained.

Grease bearings: Most motor manufacturers recommend replenishing or replacing the bearing grease every 5,000 hours, but other motor manufacturers use sealed bearings so no greasing is required, Klemmer said.

Measure the FLA: “Occasionally measure the full load amps (FLA) of each motor to make sure it’s operating within manufacturer’s specifications,” Johnson recommended.

Fixing the fans

Next up are the drying systems fans. Johnson warned that there is nothing more dangerous to employees and customers than being near an air producer when the fan disintegrates. In almost all cases, this can be avoided by following a simple monthly inspection checklist.

Clear inlets: Operators should check frequently to make sure the inlet screen is always clear and unrestricted, Johnson said.

A blower assembly with an impellor should be regularly inspected to be kept free of debris, Klemmer said. Also, the screen should be securely fastened to the unit to prevent the accidental ingestion of foreign objects.

Clean fan blades: Any accumulation on fan blades can cause an out-of-balance condition that can ultimately cause fan failure, according to Johnson. Thus, any accumulated debris should be removed from the fan blades.

Beware of vibration: “In the event that any unusual noise or vibration is detected, the unit(s) should be shut down and carefully inspected to determine the cause,” Klemmer said. “Most dryers today have impellors that run at 3,600 rpm. Ignoring or delaying inspection can lead to very dangerous situations and the repairs can become costly if ignored.”

Johnson described the process of running each motor separately to identify the one with the vibration. Here, to be safe, each should be shut down at the breaker panel until the problem can be identified and corrected.

Ducts, bags and exteriors
Look for leaks:
Dryers are designed to discharge air only at the intended outlet or discharge area. If a leak is discovered in a dryer’s duct or bag, corrective actions should be taken to optimize performance, Klemmer said. Left unchecked, a leak will compromise drying performance, and the motor can climb out of FLA range causing overheating and possible motor failure.

Keep it clean: Accumulated film can form on dryers, and it is usually caused by dirt or other materials blown up from open pickup beds, Johnson noted. Another contributor is airborne reclaimed water and chemicals from the wet section of the carwash. Though exterior dirt may not affect the dryer’s operation, it does make a statement about how well a carwash is maintained.

“What the customer sees at the end of the wash will weigh heavily on how they remember the entire operation,” Klemmer said. “That’s why keeping your dryers clean and in good service is just as important as maintaining any other aspect of a facility’s appearance.”

Realistic expectations

When dealing with dryers, operators should have common-sense expectations for their dryers. While some dryers perform better than others, none will remove 100 percent of the water from 100 percent of vehicles, Johnson said. A list of things that can affect dryer performance includes:

  • The number of nozzles;
  • Motor horsepower;
  • Positioning;
  • Conveyor speed;
  • Amount of drip space;
  • Type of rinse additive used; and
  • Air temperature.

“When looking at a new or existing dryer, operators must keep in mind a realistic expectation of what a drying system can accomplish,” Klemmer said. “The events that occur prior to a vehicle reaching a dryer will affect the overall performance regardless of the dryer’s engineering.”

Often a dryer may have been undersized when it was installed. The two most obvious reasons a smaller dryer may have been chosen are the amount of line space and the electrical power available. Sometimes additional air producers can be installed on an existing dryer if the electrical service will allow it, but Johnson noted that there is no simple, inexpensive solution to correct an undersized system.

Easing back on energy

Johnson said there are a few methods that may help older drying systems use less energy during their operation. One of the biggest users of energy with any dryer is the surge of power that occurs when the motors are started. A control circuit called a “look back” helps reduce power usage during motor startup by keeping motors running if another vehicle is approaching the dryer.

Also, dryers with multiple motors should have a “step-start” circuit, Johnson stated. This circuit starts motors in sequence so the in-rush of current never exceeds the level of a single motor.

Another option is installing a Variable Frequency Drive (VFD), which will keep the energy in-rush down. Under the right conditions, a VFD can reduce electric bills substantially by bringing motors up to operating speed slowly. “Before installing a VFD, operators should spend some time comparing the energy savings to how long it would take to pay for this sometimes expensive equipment,” Johnson recommended.

Pesky spot-free

The introduction of spot-free water to the industry during the 1990s gave many manufacturers new challenges, Klemmer said. Reverse osmosis (RO) or spot-free water creates problems for dryers since the water has a tendency to want to bond to the vehicle surface or “sheet” making it much more difficult to remove.

Prior to RO water, carwash operators were able to apply a simple cold wax or cheater wax to the surface and get a break that released surface tension. Water would run off the vehicle leaving large dry surface areas, and dryers were then able to remove the remaining water. Klemmer explained that it is much more difficult to achieve that same break of water and release of surface tension with RO water.

Instead what can be seen in today’s carwashes are much more highly developed drying agents that attempt to shed the water from the vehicle’s surface. The end result is the water beads up like rain drops instead of breaking, leaving a greater amount of water that adheres to the vehicle’s surface. Klemmer pointed out that, to overcome this, some dryer manufacturers developed more powerful, more efficient systems while others simply increased horsepower.

Drying agents, when used properly with RO water, can help dryers meet the challenge of removing the water. “However, most operators will agree that the benefits of spot-free water far outweigh the problem of removing it,” Johnson stated.

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