“Another way to keep the cost of engine exhaust removal systems down is to increase the volume of air moved by the fan,” Jefferson continues. “The fan can be oversized to draw room temperature air into the system, which mixes with the hot exhaust gases to keep the overall temperature to a level where cost-effective components can be used,” he suggests.
Adding to the discussion, Monoxivent national sales manager Erik Swanson endorses the idea of adding more ambient air into the system in order to keep it cool, while suggesting other VE system changes, as well. “We may also add high-temperature accessories to the exhaust fan such as heat slingers, high-temperature paint and other suggestions,” Swanson explains.
“In an extreme case, where the vehicles may go into regeneration mode while attached to the vehicle exhaust system, we could possibly recommend utilizing a 2,000 F flex hose,” he adds.
Toward a Safer Work Environment
Monoxivent’s Swanson looks to overall safety as part of the VE system improvements that can enhance the working environment. “We can put heat-resistant handles on our tailpipe adaptors to help prevent the mechanics from getting burned,” he suggests. “Mechanics have to keep in mind that today’s engines are running hotter, which creates more heat in the vehicle exhaust system. They must exercise care when removing the VE system from the vehicle, because it may be hot, especially right after the vehicle is shut down,” Swanson adds. He even suggests that vehicles be pulled outdoors to conduct certain engine tests that will definitely create high exhaust gas temperatures, and that the vehicle be disconnected from the VE system to do so.
Combining Old Engines with New Engine Maintenance Ops
“For the time being, service managers could designate one or two work bays of their facility for the service of new vehicles,” Swanson suggests. “These bays could be outfitted or retrofitted with higher temperature, higher air volume exhaust extraction equipment and leave the rest of the facility as is,” he reasons. “As more of the higher temp engines are introduced into the fleet, more bays can be retrofitted with high-temperature exhaust hoses and equipment,” Swanson concludes.
VE System Design Refinements Sense Load Capacity
Shawn Smith, vice president of Operations at Plymovent, Cranbury, N.J., urges a thorough understanding of usage capacity for the VE system, including considering the percentage of drops that will be in use at a given time. “Service managers need to get a clear snapshot of all types of vehicles that move through the service area,” he recommends. “Planning should include a temperature monitor at each of the extraction points to ensure that no vehicle in maintenance reaches or exceeds an approved temperature level,” Smith says.
Outsourcing Regeneration Servicing
Car-Mon’s president, Fred Imming, points to an industry trend that is influencing maintenance of higher temperature bus engines: outsourcing maintenance services to engine manufacturers. The Chicago Transit Authority (CTA) designates two bays in at least one of its bus barns for regeneration and subcontracts the maintenance work out to engine companies, he says. “Normally, they have two people from Cummins designated to come out and evaluate the catalytic convertor maintenance,” Imming says. “You have to plug regeneration by laptop link to a computer program,” for scheduled maintenance, he explains. Otherwise, catalytic converter regeneration can occur on the road, he adds.
All the more reason to have VE systems checked for extremely high-temperature performance ability in those bus bays where regeneration maintenance is scheduled, Imming suggests. In a world where technical improvements in engines are taking place, engine service managers need to review the basics and ante up for vehicle exhaust systems that will match the oncoming requirements while providing improved safety and security in their operations.
Management of exhaust is one of the key components to any service function. New VE systems solve a practical problem and they are affordable and available today.