AEROVENT CASE STUDIES

Air Handling System Turns Hangar into Paint Spray Booth

Overview

Interjet Airlines is one of Mexico’s first regular low-cost airlines. The company operates from its headquarters at Mexico City International Airport and from Toluca International Airport.

The airline was founded in 2005, but despite its youth, Interjet is quite progressive. In 2007, it began development of its 864,000-square-foot Aircraft Maintenance and Repair Center at the Toluca Airport. This maintenance facility offers major repair and painting services for large aircraft.

Working through its Mexico City-based engineering firm, DIIN Ingenieria, Interjet set out to build its maintenance facility from scratch. And when it came to ventilating the area where large aircraft would be painted, DIIN Ingenieria selected Aerovent representative Fred P. Heinzmann Co. of Houston, Texas to supply the air handling system. DIIN Ingenieria worked closely with Fred P. Heinzmann’s outside sales engineer, Andy Freeman. “We received a bid invitation from Interjet’s engineering firm,” said Freeman. “The airline wanted to build a new hangar to spray paint its own planes as well as planes from other airlines. They wanted to make a large hangar the spray booth—the whole hangar.”

Challenge

Stand-alone paint booths can be purchased. However, Interjet wanted its new paint booth to be comprised of an entire hangar bay with the ability to prevent overspray and fugitive pollutant emissions while maintaining close proximity to its maintenance shop.

For its painting hangar, Interjet wanted custom air handling units with a small footprint, quiet fan package, good filtration, and low velocity filtered supply air with laminar flow. “They wanted small, quiet, dependable, fairly priced units that could run every day,” Freeman said.

Laminar airflow was important to the success of this project. “Interjet wanted straight-line airflow,” said Freeman. “They didn’t want the air swirling as it came out of the duct because that could lead to overspray.”

Interjet also wanted the capability to scrub the air before it left the building. This meant that the paint hangar’s exhaust air needed to filter out particulates and paint and/or solvent-based hydrocarbon compounds. To accomplish this, Aerovent engineers had to design a high-volume, low-velocity air handling unit with inline filtration capable of maintaining lightly positive pressure within the painting hangar and less than a 1-inch differential across the filters. In addition to these specifications, Interjet also required its new facility to comply with U.S. codes and standards for this type of facility.

Solution

Fred P. Heinzmann Company supplied a custom-designed air handling system including three centrifugal Filtered Air Supply units, three centrifugal Filtered Air Exhaust units, system controls, VFDs, and the interface that drives the system, all from Aerovent. The Aerovent design team worked with Interjet and DIIN Ingenieria to design the entire air handling system.

On one side of the hangar, three Air Supply units pull in outside airthrough filters that remove airborne particulates, such as dirt, dust, and pollen. Each of these double width, double inlet, VFD controlled 44.5-inch centrifugal blowers run at a top speed of 657 RPM to produce 44,000 CFM at 1-inch of pressure for a total of 132,000 CFM of supply side air. Fabric duct socks connected to a common supply plenum disperse the air from the top of the hangar. The air travels toward the floor, picking up paint spray along the way.

On the other side of the hangar, three Air Exhaust units pull air through grate-covered ducts located in the floor. The air passes through a series of filters disposable pre-filters that capture paint and particulates and two stages of carbon filters that remove hydrocarbons—through the centrifugal blowers, and is discharged to the outside. Each of these single width, single inlet, VFD controlled 55-inch diameter centrifugal blowers run at a top speed of 720 RPM to pull 44,000 CFM for a total of 132,000 CFM of exhaust side air.

With the supply and exhaust units operating as a cohesive system to provide ceiling-to-floor laminar airflow, the VFDs for both supply and exhaust units are adjusted to maintain a slightly positive pressure (less than 0.1 inch W.C.) within the hangar. “If there’s too much positive pressure, it will force the dirty, contaminated air to the outside before it is adequately filtered,” said Freeman. “There needs to be a certain differential across the filters for them to be effective.”

Maintaining the ideal pressure inside the hangar is challenging because of the large door where aircraft enter and exit. Therefore, the door must remain closed while planes are being painted. “The system handles 132,000 CFM on the supply side and 132,000 CFM on the exhaust side,” Freeman said. “It’s almost neutral, pressure-wise. We created an envelope of fresh filtered air around the plane.”

A quiet system with a small footprint was also important to Interjet. “These units were engineered to run at lower speeds for quiet operation and used belt-driven blower to make the fan package as compact as possible,” Freeman said.

Interjet personnel set the speed of the fans. In addition to temperature and humidity conditions, the pressure differential across the filter system is closely monitored. When this pressure exceeds 1 inch, an alarm indicates that a filter change is necessary. “When the filters are new and clean, the blowers can operate at lower speeds because there’s less resistance to the airflow,” said Freeman. “But as the filters load up, fan speeds need to be increased to recover the pressure lost across the dirty filters.”

Results & Benefits

Aerovent supplied the custom air handling equipment, supporting system components, and the engineering expertise to create Interjet’s air handling system. However, the fan company’s involvement in this project transcends merely manufacturing and supplying equipment. Not only did Aerovent design Interjet’s entire paint hangar air handling system, the company overcame challenges to do so. While the original request for bid specified extremely unique requirements, Aerovent worked with Interjet to overcome these challenges and meet their exact needs.

“Interjet needed a custom-designed air handling system,” Freeman said. “We feel we were successful on this project. We were able to meet Interjet’s noise/sound criteria as well as to maintain a small system footprint. The fact that the system efficiency is high is an added bonus..”

According to Freeman, Interjet was extremely happy during the bidding stage, the building process, and is “extremely happy with the final product because it performs very well and exceeds expectations.” he said. “Aerovent has been building custom air handling units for many, many years,” said Freeman. “I consider Aerovent to be an authority in the fan industry.

And that translates to satisfied customers in any language.

Overview

The University of Windsor in Ontario, Canada installed two new wind tunnels in its recently constructed Ed Lumley Centre for Engineering Innovation. The large tunnel, made by Aldon Sheet Metal, Windsor, Ontario, is more than 57 feet long. The small tunnel, made by Industrial Metal Fabricators, Chatham, Ontario, is nearly 40 feet long. The test areas of both wind tunnels are oriented horizontally. However, the small tunnel operates within a closed loop, which has vertically oriented sections.

Wind tunnels are used in many types of research to study the effects of air moving past solid objects. Dr. Shaohong Cheng, associate professor, Department of Civil and Environmental Engineering at the university, is responsible for the large tunnel. According to Dr. Cheng, this tunnel will be used to study wind-induced environmental, automotive, and structural issues. Both tunnels will help engineering researchers develop renewable energy sources, improve automotive efficiency, reduce air pollution, and design sustainable infrastructure.

Although the university brought in two different contractors, both Industrial Metal Fabricators and Aldon Sheet metal insisted on working with Larry Mills, sales engineer at Ironross Price Sales, an Aerovent representative located in

Sarnia, Ontario. “Both contracting firms know me and my company well,” said Mills. “Both firms had experience with Aerovent fans over the years, and both wanted to use them for these projects.”

Challenge

Typically, wind tunnels require relatively high airflow at relatively low static pressures. The University of Windsor’s two new wind tunnels are no different. In addition, the tunnels required streamlined airflow as well as a way to change the flow and pressure characteristics on location if necessary.

The actual size of the fan for the large tunnel was the main challenge. “The large amount of airflow within a small room requires special consideration,” Mills said. “The wind tunnel is a major machine. It’s critical to communicate the importance of room design as well as proper safety procedures.”

The university wanted the fan motor for the large tunnel to be a direct-drive unit, and the fan motor for the small tunnel to be belt driven. The small wind tunnel presented a specific challenge because the university wanted it to duplicate an existing tunnel. However, there were no nameplates on the equipment; therefore determining its parameters and characteristics was difficult, but not impossible.

“I was called in to check the existing tunnel to try to determine the airflow,” Mills said. “Without a nameplate, no one seemed to know the tunnel’s rating. I worked with the university to come up with an estimate of what it would do.”

Fortunately, based on the company’s experience in calculating airflow, Industrial Metal Fabricators was able to establish a mock-up, which helped with the tunnel’s performance estimate. “We collaborated on a redesign of the ductwork to make the new small tunnel a little more streamlined,” said Mills.

Solution

Ironross Price Sales provided two Type VW vaneaxial fans, both from Aerovent. The 60-inch, 60-HP, 1,180 RPM fan for the large wind tunnel is a direct-drive unit capable of supplying up to 110,000 CFM and up to 0.7 inch static pressure.

The 48-inch, 30-HP, 1,322 RPM fan for the small tunnel is a belt-driven unit capable of supplying more than 40,000 CFM and up to 2.75 inches static pressure. Fan motor speed for both tunnels is controlled through variable

frequency drives. If it becomes necessary to change the flow and pressure characteristics of either tunnel, both fans are equipped with adjustable-pitch blades.

Streamlined flow is a primary wind tunnel requirement. “A vaneaxial fan should be used when the application requires high air flow and low pressure,” said Mills. “So the Aerovent Type VW was the right fan for this job.”

The Aerovent vaneaxial propeller is specially designed to work with guide vanes. The overall mechanical efficiency of vaneaxial fans is typically higher than other axial-flow fans. The guide vanes improve efficiency and pressure characteristics by converting rotational energy at the propeller discharge into useful work.

Results and Benefits

Aldon Sheet Metal, Industrial Metal Fabricators, and the university wanted to use Aerovent fans because of their high quality and reliability, according to Mills. “Aerovent is very well known for vaneaxial fans,” he said.

When the small tunnel was commissioned, feedback from Industrial Metal Fabricators indicated that the fan ran smoothly throughout the motor’s frequency range. During proof of performance testing, air velocity reached 7,000 feet per minute (FPM), or 43,750 CFM, which is well above the design rating of 6,000 FPM, or 37,500 CFM. The tunnel it replaced could only attain 4,600 FPM, or 28,750 CFM. At the recommended full speed, the 30 HP motor current is only 18A. The university is very pleased with the fan’s performance because it

exceeded their expectations.

Although the size of the large tunnel could potentially limit its use within a relatively small room, steps were taken to emphasize proper and safe operation. Instead of just delivering a high quality fan, Mills took the time to explain the special considerations that accompany equipment of this size and ways to deal with them to get the most from the investment.

Because of the performance, quality, efficiency, and reliability of Aerovent’s vaneaxial fans, the University of Windsor’s new wind tunnels will provide engineering professors, researchers, and students with improved and expanded

testing capabilities.

Power generation is a complex process. It takes an act of congress (figuratively and literally) to build, operate and maintain a power generation facility. Ventilation equipment should not add to this complexity. Rather, the equipment should be tough enough to avoid operational failure and to minimize installation and repair work. The rugged, high-performance fans Aerovent provided to a state-of-the-art hybrid energy center, were ideal for the task. Aerovent was chosen for this project because of their reputation for building large custom fans for extreme industrial applications.

THE CHALLENGE

The energy center’s primary requirement was that its chosenvendor be able to des ign and build a set of the most rugged, efficient roof ventilators within budget. Most roof ventilator fans last between 10 and 20 years when properly maintained. Because of the permits and cost involved in performing maintenance work on the roof of a power plant, they wanted their fans to have a longer life span (up to 40 years). This lifespan requirement meant that the fans had to be constructed using industrial grade materials and components.

THE AEROVENT SOLUTION

Aerovent’s solution was to build twenty-six 96” diameter Tu-Way roof ventilators, driven by premium-efficient severe-duty motors. The energy center wanted the larger- diameter fans to reduce the total number of roof openings,

thereby reducing construction costs and the risk of future leakage. Aerovent’s experience with custom-manufacturing large roof ventilator fans made it the perfect choice. To ensure the fans’ ruggedness yet keep them lighter-weight for rooftop placement, most parts were made out of galvaneal, a special paintable metal dipped in molten zinc. A protective coating was applied on top of the painted galvaneal surface to make it even more corrosion resistant.

THE CHALLENGE

Another important requirement of the power company was to achieve 128,000 CFM exhaust flow, along with the ability to run the fans in supply mode as well. The high CFM was required to keep the cavernous turbine and boiler buildings tolerable for workers during the summer months. In the event of air contamination or any other hazard, the power plant needs to be able to reverse the fans in a hurry in order to supply fresh air into the buildings.

THE AEROVENT SOLUTION

Aerovent’s fan propellers provide equal airflow in both directions. Other companies’ fans have a standard-exhaust one-direction propeller and are run backwards for the supply mode, producing about 40 percent of exhaust-mode airflow. Aerovent fans produce 100 percent airflow in either direction. Aerovent also produced an integrated electrical control system guaranteed to work with its fans instead of the power plant having to acquire a separate system from another source. The system features an onboard starter- disconnect switch, which boosts the motor’s start and can be easily disconnected.

THE CHALLENGE

Fire safety is a challenge in any environment, and especially so in a power plant. In case of a fire, the first priority is to ensure the safety of employees. Another goal is to be able to salvage expensive equipment in the building. With ventilation fans, if the motor fails during a fire, it is more beneficial if the fan’s dampers automatically fail in the “open” position, and allow smoke to escape.

THE AEROVENT SOLUTION

Aerovent’s expertise in custom-building fans for complex applications, like this energy center, allowed them to design and construct a special fire damper for the fans. When the motorized damper is activated, a metal linkage arm attached to the damper blades moves to open or close the damper. Aerovent’s custom-made damper features a fusible linkage arm with a “soft metal” section in the link. When temperatures reach 212 degrees (as in the case of a fire), the soft metal plate fails, breaking the linkage, and a heavy counter weight swings the damper into the “open” position.

Overview

The Beauharnois Hydroelectric Power Station on the Saint Lawrence River in Quebec, Canada is one of the largest hydroelectric power plants in the world. Located 25 miles southwest of Montreal, the main building containing the power station is constructed atop the Beauharnois Dam.

Hydro-Quebec, owner and operator of the dam, brought in Dessau, one of Canada’s largest engineering-construction firms, to revamp and modernize the power plant which stretches nearly a half mile across the Saint Lawrence River and contains 38 hydroelectric turbines capable of generating up to 1,903 MW of electrical power.

A major part of the Beauharnois Hydroelectric Power Station renovation involved placing the existing ventilation fans, which were installed on the roof of the building in the 1950s. The key was to provide more than twice the existing CFM without adding a significant amount of weight to the structure. The building could not be modified because of its Canadian National Historical Site status. Dessau produced designs and coordinated much of the work, ensuring that the rehabilitation activities had minimal impact on operations; that part of the station continued to function during renovations; and that the integrity of the art deco architecture was preserved.

Dessau turned to VDDO Inc., an Aerovent representative located in Delson, Quebec, to help them meet the fan replacement criteria. VDDO engineers and representatives help clients evaluate and select air movement and air quality equipment such as fans, coils, controls, dampers, and diffusers.

Challenge

The structural requirements of the historical building limited the total weight of the fan, which could not exceed 3,800 pounds. In addition to the weight restriction, Hydro- Quebec required the new fans to have a projected service life of 25 years.

Hydro-Quebec also required fans that could be taken off the roof in one piece. Normally, the fan hood would be removed first, followed by the rest of the fan. In this case, Hydro-Quebec wanted to be able to unbolt the fan base plate and remove the entire fan from the roof – with hood attached – in the event a fan needed to be serviced or replaced without spending unnecessary disassembly time.

The new fans also had to achieve strict noise criteria: 78 dBA at 5 feet. Hydro-Quebec didn’t want the new fans generating noise because of the people working in the building. They wanted the fans to be as quiet as possible.

Solution

VDDO supplied 14 model VJ direct-drive, adjustable-blade, vaneaxial fans and fourmodel HD53 direct-drive, hooded, upblast roof ventilation fans – all from Aerovent.The VJ-type fans produce 55,000 CFM, while the much smaller HD53-type fans produce 7,000 CFM.

Standard fan hoods are made of steel, which makes them heavy – too heavy for this application. Aerovent made the custom hoods for this project out of aluminum to reduce the weight. While the weight restriction was 3,800 pounds, the VJ fans weighed only 775 pounds.

Because Hydro-Quebec specified fans that could be taken off the roof in one piece, Aerovent designed the special aluminum hoods to be part of the integral structure of the fan. Not only did the custom hood have to be light, it had to be strong as well.

“The VJ fan is fairly quiet,” said Eric Routhier, engineer and partner at VDDO. “That’s the reason it was chosen. It allowed Hydro-Quebec to meet all the performance criteria – including the low noise level. Plus, the fan blade is adjustable, so if at any point in the future, they need to modify the performance, Hydro-Quebec can adjust the blade angle to fine tune the system and obtain the necessary flow.”

Whereas the adjustable blade feature is standard on the VJ fan, much of what Hydro- Quebec specified required customization. Not only was the integral hood a special item, the fans used a special 20 HP motor to accommodate Hydro-Quebec’s 25-year life requirement. These motors are built to the IEEE 841 specification. IEEE-841 identifies the recommended practice for severe duty induction motors in order to enhance their reliability and maintainability.

To ensure longevity of the fans, the fan casings were constructed of hot-dipped galvanized steel. The lubrication and relief lines were customized as well. Instead of copper, Hydro-Quebec specified stainless steel.

Results & Benefits

VDDO and Aerovent provided the right mix of axial fans with the capabilities to meet the desired airflow, noise level, and weight requirements. Hydro-Quebec received quiet, long-lasting fans that provide better ventilation than the ones they replaced and require virtually no maintenance other than routine lubrication.

Many of the older turbines are air cooled, and had to more than double the CFM to extract the heat produced by the turbines to maintain the desired building temperature.

Upon seeing the requirements, Aerovent quickly knew they were able to meet them. “We represent many different fan lines,” Routhier said. “But with all the changes and customizations, we couldn’t have done this project without the help of the people at Aerovent. They made it happen; in my book, they did what needed to be done.”

According to Routhier, Hydro-Quebec has started work on a similar building 60 miles away. The company must be pleased with the solutions that VDDO and Aerovent provided because they are including the same types of fans in the specification – definitely a good investment.

Overview

New Mather Metals, a manufacturing plant that produces heat-treated metal products (including automotive components) commissioned Aerovent to provide unique solutions for their facility needs. Two separate projects were required for this particular application – both involved examining a process that used an oil-quenching cooling system to cool automotive suspension bars that were dipped in hot oil. The contractor on the project, Alex Buchner of Profab Metals, along with Ted Ogle of Ogle Equipment Sales worked together to assess and develop a plan with proposed solutions. In the end, the result of the two projects was a much-improved work environment with cleaner, fresher air for the employees.

Challenge

The oil-quenching cooling system at New Mather Metals was a significant challenge. The course of dipping the heated bars into the oil produced tremendously hot, oily vapor that dispersed into the air, coating the ceiling, walls and machines. Not only did it make an extremely dirty environment, but the vaporized oil created a blue haze around the lights and built up on surfaces within the plant. Project #1 involved finding a solution to containing and cleaning the air. This required developing a system to capture the large oil particles, isolate the remaining hot oily vapor and then exhaust the air out of the building.

Project #2 at the plant required forming a method to cool the heated suspension bars so that employees could efficiently handle them with thinner gloves. The process that was currently in place involved removing the suspension bars from the oil at 1,700 °F, where they became hard and brittle. To strengthen the bars and give them flexibility, they were put into another oven and heated again, to 1,000 °F. Afterward, the bars were sent through a cooling station which used outdoor air to cool the metal. Personnel then handed the bars using thick, cumbersome gloves. At the request of the engineer, cooling the bars further would allow the workers to wear thinner gloves resulting in increased efficiency from easier handling.

Solution

Project #1 involved a two step plan for resolving this problem. The first step was to capture the larger oil particles through an exhaust system, which would then extract the oil with an oil mist collector and then return the oil to a reservoir. The second step required enclosing the area to capture the remaining, smaller oil particles to keep them from infiltrating the plant.

A solution was devised to enclose the fifteen feet high, eighteen feet wide, and thirty-six feet long steel beam support structure. Twelve inch strip curtains with a three inch overlap were draped from the structure to isolate the area, which effectively blocked the cross drafts in the factory and helped to contain the dirty air. In two areas strip curtains could not be used because a robot and a transporting conveyor were in the way, so instead, air curtains were added to maintain the integrity of the enclosure.

Next, three (3) eight feet wide by twelve feet long canopy hoods were installed on the structure. The twenty-five inch diameter Aerovent Vaneaxial fans were mounted on each hood and their ducts extended out through the roof. Each fan exhausted 10,000 CFM of the dirty air, which totals about 100 FPM per hood, successfully ventilating the area.

The solution to Project #2 was straightforward. To meet the challenge, one VTBD exhaust fan and two VTBD supply fans were mounted on a platform with the purpose to blow plant air over the bars. This effectively cooled them an additional 100°F, which successfully allowed personnel to handle the bars with thinner gloves.

Benefits

Aerovent fans provided the ideal solution for this application. In addition to their ability to operate with oil buildup on the props, they were selected because they could provide the necessary velocity to pull the air through the enclosure. New Mather Metals wanted an enduring solution, and they knew they could depend onAerovent fans to function reliably for the next 20 to 30 years.

Aerovent VTBD Vaneaxial belt-driven fans are characterized by their ability to handle airflow to 81,200 CFM and static pressure to 4.5" w.g. These fans are regularly used in applications such as in-duct space ventilation, roof mounted

ventilation, industrial fume exhaust, and high temperature process ventilation. An A240 high temperature aluminum alloy propeller and high temperature lubrication are available to make this fan suitable for airstream temperatures up to 600°F. In addition, a belt-driven design makes the Aerovent VTBD particularly well-suited for applications where the motor needs to be kept out of the airstream because of dirt-laden, hot air. Its belts and sheave are enclosed in a metal tube to protect them from the airstream, and the motors are totally enclosed and drip-proof, allowing for continuous operation.

Summary

New Mather Materials wanted to provide a better work environment for their employees by cleaning up the oil-filled air in the plant. This challenge was met by the ingenuity of Profab Metals and Ogle Equipment – and solved using high-quality, durable Aerovent fans.

Overview

Wastewater treatment plants must be good urban neighbors by ensuring that odors from their processes are minimized. Hydrogen sulfide, or H2S, forms in the early processing stages, and is typically the primary cause of odor emissions. Large urban wastewater plants have a growing number of odor treatment options from which to choose - many of which require the use of robust and reliable air moving equipment.

The wastewater treatment facility operated by Lakehaven Utility District, Des Moines, WA, controls odor by pulling the air from the plant’s headworks, primary clarifiers, and sludge processing areas; filtering it through packed-bed chemical scrubbing towers; and exhausting it to atmosphere. Make no mistake: applications like this require the use of high quality industrial grade fans.

The fans on the odor control system at the Lakehaven plant had been in place for nearly 30 years. Over the course of time, they had corroded severely because of the H2 S as well as the chemicals used to eliminate it. The treatment facility was in need of new fans – corrosion resistant fans. Lakehaven turned to Aerovent representative, Ron Beyersdorf, David P. Wilson Company, Bellevue, WA, to specify the proper fans for the system.

Challenge

The facility’s primary concern was controlling odor. “We are required by ordinance to not emit any odors,” said John Barton, wastewater operations supervisor at the Lakehaven treatment plant. “The plant is one block off the beach in an extremely affluent area.

”Because the 30-year-old fans were so corroded, it was imperative for their replacements to be highly corrosion resistant. “The existing fans were stainless steel,” said Beyersdorf. “The process was corroding them. They were being eaten away.”

Replacement fans would have to fit into the existing space. “We were replacing another manufacturer’s fans,” Beyersdorf said. “Because of that, we had space and ductwork configuration constraints to work around.”

The older fans had 100 HP motors. Replacement fans could not exceed this rating because doing so would require Lakehaven to change most of the electrical components and the wiring that supplies power to the fans.

Noise was also an issue. “They wanted the fans to be as quiet as possible while allowing adequate access for maintenance,” Beyersdorf said. “One of the fans is installed in a relatively small concrete-walled room. Previously,

they had blankets hanging from the walls to attenuate the sound.”

In addition to increased corrosion resistance, form factor, horsepower rating, and low noise, other fan requirements included:

• Volume of at least 23,000 CFM

• Static pressure of at least 18 inches

• Quiet, smooth operation

• Efficiency

• Ease of installation

• Ease of maintenance

• High reliability

Solution

David P. Wilson Company supplied two BCF 330 fiberglass fans from Aerovent. The 33-inch, centrifugal, backward curved, high pressure fans are designed for handling corrosive or caustic air in high pressure applications where conventional steel and stainless steel fans are not suitable. The BCF’s carbon-fiber-reinforced wheel is designed for maximum efficiency, quiet operation, minimal weight, and optimum strength. It features a wide wheel and housing, which produce high volume, low velocity air movement.

Competitors’ fans would have to use a fiberglass and stainless steel combination to obtain the required speed and performance. “But Aerovent fans were able to exceed the performance requirements with fiberglass and

carbon fiber wheels,” said Beyersdorf.

Noise was also an issue at the Lakehaven treatment plant. “They wanted the fans to be as quiet as possible while allowing access for maintenance,” Beyersdorf said. “The backward curved wheels are quieter than other blade

designs. They don’t impact the air the way straight radial blades would.”

According to Beyersdorf, these backward curved fans met the pressure and flow requirements and they’re more efficient than other blade designs. He also said that the two BCF fans are identical, except for rotation. “One fan has a clockwise rotation and the other has a counter-clockwise rotation,” he said. “Because of the space and ductwork configuration constraints, one of the fans had to have an opposing rotation to fit the existing duct layout.”

The 100% wheel width of the BCF fans easily produces the required 23,520 CFM at 18 inches of static pressure. The speed of each belt-driven fan is around 2,200 rpm. “A speed of 2,200 rpm is not a good fit for direct drive,” said Beyersdorf. “You either have to over-speed an 1,800 rpm motor, or you have to run a 3,600 rpm motor slower, which would require a larger motor because it would have to be derated.”

Results & Benefits

The Lakehaven wastewater treatment facility can continue being good urban neighbors by controlling odor emissions. Because the plant’s odor control system uses Aerovent’s corrosion-resistant fiberglass/ carbon fiber fans, clean air is exhausted to the atmosphere.

In addition to exceeding all performance requirements, the new fans are more efficient. “We were at the point where we had to run the old fans at 100% all the time,” said Barton. “Now, we’re able to turn them down to about 50%. We would have odors if we ran the older fans at less than 100% because we weren’t moving enough air. These two fans are evacuating air from two 30-foot-tall bio-towers. They have to move a certain amount of air across those towers. It takes less energy to move more air with the new fans.”

According to Barton, the BCF fans from Aerovent are cleaner electrically and have much less vibration. “The new fans are definitely superior to the ones we had,” he said. “They are much smoother, much cleaner electrically–less harmonics–they’re really good fans.”

Barton is also pleased with the support that the David P. Wilson Company provided. “Ron was extremely helpful with the technical aspects of the fans themselves, and also the installation,” he said. “He was here for the startup, but he was also here to answer questions about the actual installation.”

“For this application and performance requirements, the BCF is the best fit,” Beyersdorf said. “Aerovent is the only fan company that could meet all the requirements the customer needed.”

Water rationing and raging wildfires during summer months, along with strict health department regulations, lead regional water treatment facilities to Aerovent to help them

operate safely and efficiently.

Running a water and wastewater treatment facility can present many challenges, especially when the facility is faced with the added burdens of water rationing plans, raging wildfires that must be quickly extinguished, and

strict health department regulations that must be met to receive an operating permit.

The Challenge

Gases and chemicals present in water and wastewater treatment facilities can cause corrosion, equipment failures, unsafe working conditions (even explosions), plant shutdowns, and increased maintenance and operation costs.

The air handling systems and ventilation equipment used in these installations must be designed to meet this challenge. Generally, standard commercial grade HVAC equipment is not suitable for these types of corrosive environments.

The Aerovent Solution

Aerovent’s fiberglass axial TF fans are ideal for forced draft aeration and dilution ventilation. A 2-million gallon ground reservoir with six Aerovent 43” TF fans can exhaust a total of 120,000 CFM. The TF fans are sized to exhaust one air change per minute, based on average high and low water levels inside the tanks. Fresh air is drawn through screened aerators and overflow vents. Large volumes of fresh air mix with the aeration process to dilute and substantially reduce corrosive gas levels. In addition, fans can be staggered to distribute air and eliminate condensation and corrosion on interior tank surfaces.

THE CHALLENGE

A second challenge is strict health department requirements that must be met for the plant to receive an operating permit. One of these requirements is that tank vent fans must be “insect-proof ” since insects can introduce disease into the water. Fans must also be rust resistant to ensure structural integrity and to avoid rust streaks on the facility’s exterior.

To meet the insect-proof requirement, fan curb base and exhaust damper specifications require continuous, insect-proof neoprene gaskets mechanically fastened with 316 stainless steel hardware to pass inspection. Adhesives are not acceptable because gaskets have fallen off and into tanks in the past. Aerovent fans meet these specifications and also include a special insect- proof gasket arrangement.

THE AEROVENT SOLUTION

To ensure rust resistance, Aerovent fans are constructed of all fiberglass with type 316 stainless steel shaft, motor pedestal, motor slide base, lube lines and hardware inside and out. Other commercially manufactured products use coated or encapsulated steel, which can cause rust to occur more quickly and cause exterior rust streaks.

For easy access to the fan’s propeller, shaft seals and bearings for maintenance and repair, Aerovent uses Type 316 stainless steel collar washers and bolts to secure the propeller. This construction isolates the bearings from the corrosive exhaust air and maintains its “insect-proof ” integrity. It also avoids the problem of cracked fiberglass, fan imbalance and corrosion that can occur when resin coatings must be removed or a hub has to be pulled away from a shaft to gain access.

Agricultural-Sugar Beets

More than half of the sugar produced in the U.S. comes from sugar beets. Annually, more than 25 million tons of sugar beets are produced on 1.5 million acres yielding 4 million tons of refined sugar. In the Upper Midwest, sugar beets have a growing season about five months long. Harvested beets are stored outdoors where the cold winter months act as a freezer until the beets can be processed. But heat can still build up inside the piles and cause excessive spoilage. Looking to reduce their spoilage rates, a major beet processing plant turned to Aerovent for a customized ventilation system that could help it maximize production, profitability and customer satisfaction.

THE CHALLENGE

Beets are harvested in autumn and early winter then transported to a processing plant. They are stored in outdoor piles where the cold winter air helps preserve them. In the Upper Midwest, sugar beets are processed around the clock between October and April. However, even when stored outdoors in frigid temperatures, the beets can start to ferment and generate heat within the piles, which can quickly rot entire mounds. To reduce spoilage rates, the core of the beet piles need to be cooled down–or ventilated.

THE AEROVENT SOLUTION

To extend the storage life of its sugar beets, the processing plant invested in an extensive cold-air ventilation system. Aerovent engineered the solution using 128 VP Vaneaxial fans. The fans were custom-fit with elbows that connected to a series of ductwork that ran through the beet piles. The ductwork, provided by the customer, was set up around the pile site with holes drilled into it to capture the cold air blown into the interior of each pile. By directing naturally refrigerated air throughout the beet piles, the processing plant was able to keep its sugar beets at a consistent temperature longer, letting it process almost the entire harvest and keeping spoilage to a minimum.

THE CHALLENGE

Aerovent’s VP Vaneaxial fan is designed for high-capacity applications requiring straight-line air discharge. The fan is installed vertically while the chilled air must be blown horizontally into the centers of the beet piles. In addition, the piles, fans and ductwork are constantly exposed to outdoor elements. The vertical fan needed to fit with the horizontal ductwork distributing the air, and the fan––and especially its propeller––needed to drain properly if exposed to rain and snow.

THE AEROVENT SOLUTION

To fit the vertical fan to the horizontal air-distribution ductwork, Aerovent created an easily attached 45-degree elbow that allowed air to be blown throughout the horizontal ductwork on the ground. Aerovent also drilled holes into the hub of the fan propeller to allow for drainage of rain and snow that could cause alignment or other problems (a common modification made in vertical installations). A final customization included the creation of a metal lid that closes up the fan unit during the off-season to help keep moisture out.

THE CHALLENGE

Each type of fan is designed to accommodate a certain amount of air pressure. In most applications, the exact pressure that will be generated can be easily predicted. But with an outdoor application, unpredictable factors can make it hard to know exactly how much energy is being generated inside the beet pile and can affect the static pressure of this application.

THE AEROVENT SOLUTION

Aerovent’s VP Vaneaxial fan was ideal for this application with many unpredictable factors. Performance features of this type of fan include airflow from 800 to 102,500 CFM and static pressure to 5” w.g. This gives the fan a high tolerance for pressure variations so it can accommodate the unpredictability inherent in such an application. Specifically, the VP’s propeller better accommodates pressure buildup, making it easier to handle the pressure and air performance requirements.

Overview

For manufacturers of paint spray booths, profitability comes from developing booth designs that minimize costs while maximizing quality and reliability. For one large spray booth manufacturer, this meant replacing the ventilation fans used in their existing booths. Because the manufacturer was disappointed with the performance and cost from their existing suppliers, the company turned to Aerovent with a challenge to provide a low-cost, highly reliable fan solution. Aerovent was awarded an opportunity to work with the company to establish customer expectations, design specifications, and goals to meet its ventilation requirements.

Challenges

When designing, developing, and producing their products, manufacturers must keep their costs low without sacrificing product functionality, quality, and reliability. While these criteria are no different for paint booth manufacturers, this company had specific additional requirements that Aerovent had to meet.

Because fans used in paint spray booth applications may be required to run continuously, they must be robust and reliable. They need to have a low profile to fit into tight spaces and to accommodate multiple design configurations. The fans also need to meet the intent of the National Fire Protection Association (NFPA) standards. Specifically, NFPA 33 which is the standard for spray applications using flammable or combustible materials.

Further challenges included fan size and performance. To maximize versatility, the number of fan sizes and propeller configurations had to be minimized. The

airflow requirements ranged from 1,500 CFM to 35,000 CFM. Static pressure requirements ranged from 0.5 inches w.g. to 1.25 inches w.g. The fans also needed to operate at a very low noise level due to the fact that operators are frequently working inside the booths.

Solution

Aerovent developed the BTABD paint spray exhaust fan, which not only met, but exceeded the established requirements. A notable feature of the BTABD exhaust fan is the special BackSweptTM propeller profile that minimizes turbulence and noise emission while providing optimum airflow. Because of its factory-set adjustable pitch blades, Aerovent BTABD fans easily provided the required airflow and static pressure. The fan housing’s belt-driven configuration also keeps the motor out of the air stream.

 Along with rugged, robust construction, permanently-lubricated and sealed bearings ensure maximum reliability. The bearing assembly also features a shorter design to minimize the fan housing size. A shorter housing enables the BTABD to be used in more booth types because they accommodate space-

sensitive designs.

 The BTABD’s adjustable-pitch blades, shortened bearing assembly and housing

work together to enable paint spray booth manufacturers to consolidate fan sizes while achieving a wide range of airflow requirements. For example, one fan size can be used in a variety of booth sizes, and can accommodate different airflow rates and static pressures by adjusting the motor size and the pitch of

the sheaves.

By understanding the needs of spray booth manufacturers, Aerovent designed

versatility and application flexibility into one robust fan. They are designed to reliably provide airflow in either horizontal or vertical directions and is available with propeller diameters from 12 inches to 42 inches. The BTABD has airflow capacities from 1,295 CFM to 36,100 CFM, and can provide static pressures up to 1.25 inches w.g. Motor sizes range from 0.75 HP to 10 HP. The fan’s shaft and bearing assembly are also mounted within an inner cylinder isolated from the airstream. The V-belt drive assembly is enclosed in an aerodynamically designed belt tube, which maximizes fan efficiency, minimizes air blockage, and reduces noise generation.

Benefits

Exceeding one large paint spray booth manufacturer’s expectations enabled

Aerovent to develop the low-cost, highly reliable BTABD paint spray exhaust

fan. Because of its responsiveness and customer focus, Aerovent turned what

was initially a custom order into a standard product line.

From small industrial open front to large units for painting vehicles or even railroad cars, all paint spray booths must be ventilated, which means they all must have ventilation fans. Because Aerovent rose to one company’s challenge, paint spray booth manufacturers now have a low-cost, versatile, robust, and

reliable fan solution that’s designed specifically for their industry.

Overview

Whether making container board or high grade deinked paper, airflow is critical to the manufacturing process. Exhausting the gas from a paper machine requires a high level of detail and engineering. Typically, hoods for a paper machine’s drying section are situated within sheet metal enclosures to conserve heat. In most of these facilities, a series of roof-mounted exhaust fans positioned above the dryer section remove the hot, moist, and often caustic exhaust from the process.

When paper machine exhaust fans don’t operate properly, it’s difficult to exhaust these fumes adequately. A leading producer of container board, corrugated, and consumer packaging paper products was dealing with issues associated with removing exhaust from one of its paper machines at a particular facility. After experiencing frequent maintenance issues and persistent bearing failures, the plant decided to pursue a more reliable solution. That’s when management at the plant turned to Aerovent representative Glenn Tripp, Industrial & Marine Air Products, Powhatan, VA for help. When it comes to fans, he is one of this facility’s “go-to” resources.

Challenge

The hood exhaust system at the container board facility consists of multiple exhaust fans mounted along the roof. The ducts from the paper machine’s drying section penetrate the roof vertically, turn 90 degrees, and come to a dead end at the edge of the roof.

The previous design was inadequate by today’s standards. Each of the existing 72-inch axial fans was mounted on one side of the 8-foot square horizontal duct section. A 10-foot jack shaft passed through, and protruded from, the opposite side of the duct where a sheave, V-belt, and motor provided the necessary rotation for the shaft and fan. There was a flange-type bearing and seal on the drive side of the duct, and two bearings within the fan housing.

When using a shaft of that length, “It starts to bow.” said Tripp. “It’s hard to keep bearings on them. It’s hard to get in for maintenance when the paper machine is running and all that heat and moisture is coming through the exhaust duct. You can’t go in the duct to work on it, so it’s extremely difficult to maintain.

There’s no question that going back to previous design would shorten the life of their exhaust system. “The guys were very frustrated,” Tripp said. “Bearing alignment was very difficult. There were three bearings that had be kept in direct alignment. Two of the bearings are very close together, but one was 11 feet away.”

If the exhaust system does not operate properly, the steam and heat from the paper machine drying section are not removed and the paper won’t dry. “They need these fans to get the exhaust out of the hoods and keep the moisture out of the building,” Tripp said. “In a paper mill, you don’t want the steam in the building because it gets up to the ceiling, condenses, and drips down on everything: the people, motor control centers, motor starters, the motors, and the paper. It’s extremely important to keep all the exhaust fans running. If you can’t keep the fans running, you can’t keep the moisture down in the building.”

Solution

Industrial & Marine Air Products supplied a Model TABD tubeaxial fan from Aerovent. The 72-inch, 15 HP, 900 RPM fan for the paper machine exhaust system is a belt-driven unit capable of supplying up to nearly 60,000 CFM at 0.75 inch static pressure, depending on system design and ductwork configuration. In this application, the fan is rated at 50,000 CFM at 0.50 inch static pressure. “It has to be the right fan for the right application,” said Tripp. “The static pressure is extremely important.”

When designing any type of fan system, the ductwork comes first. “In a closed system such as this one, the ductwork determines the static pressure,” Tripp said. “Before a fan can be selected, the resistance of the system must be known because the fan must overcome that resistance. Then the fan can be selected for the right amount of flow against that static pressure, and it will deliver the required CFM.”

Tripp had to convince the team at the container board plant that a different approach would work. Tripp proposed:

• Eliminating the trans-duct jack shaft

• Removing the old fan

• Installing the new TABD Aerovent fan where the old fan was removed

• Locating the fan motor on the same side of the duct as the new fan

• Sealing the hole where the bearing protruded on the opposite side of the duct.

 “We were successful in convincing them that this new design would greatly reduce downtime and labor cost,” said Tripp.

 After persuading the managers at the container board facility, Tripp worked with the Aerovent team to ensure the new fan matched the performance of the old fan. Aerovent designed a special belt-driven short-case fan to match the ductwork opening height and mount on the existing structure. The new fan is equipped with a 304 stainless steel propeller to inhibit corrosion.

Results & Benefits

Industrial & Marine Air Products supplied a high quality Aerovent tubeaxial fan that reliably removes exhaust from the container board facility. “The TABD is an axial flow fan,” Tripp said. “Axial flow fans deliver a tremendous amount of air for a relatively small amount of money.”

In other words, the Aerovent TABD tubeaxial fan provided the best performance for the money in this application. In addition to robust performance, the plant received a highly reliable industry-leading fan, an up-to-date system design that eliminates the reliability and maintenance issues associated with running a jack shaft through ductwork, and the assurance that the high quality of the container board products it manufactures will be maintained.

 “Our customers expect us to select the fan that provides the best performance for the lowest horsepower. Performance and efficiency are very important,” said Tripp.

 And the container board facility is happy with the Aerovent fan and Tripp’s design. “They’re thrilled,” Tripp said. “They know they received the best fan performance for the money.” Working with Aerovent is great because “they are good to work with,they stand by their products, they are flexible, and they do what they say they will do,” he said.

Overview

A steel plant located in the Midwest produces carbon, stainless, and electrical steels; hot and cold-rolled steel; as well as aluminum-coated stainless steel. The plant’s hot strip mill building is a large facility where slabs of steel are rolled into steel coils. The building is currently ventilated with upblast roof exhaust fans. Access for routine maintenance is difficult, and consequently, the roof exhaust fan bearings are beginning to fail.

Instead of replacing the roof ventilators with newer units, which would have the same accessibility problems, the steel plant decided to place fans through the side of the building instead of along the roof. The plant also wanted to access these fans from the outside of the building to facilitate installation and maintenance. The plan was to procure one fan to prove the concept, and purchase more if the fan satisfied the requirements.

The steel plant turned to Scott Zimpher at Zimpher Kyser Inc., an Aerovent representative located in Piqua, Ohio to help select the right fan to satisfy the building’s ventilation requirements.

Challenge

The steel plant required ventilation fans that could remove fumes, heat, and moisture from the building. “The existing roof ventilators are being scrapped,” said Zimpher. “Because of the years of hard usage in a steel mill, they haven’t held up to the exposure to heat and moisture. The plant needed a fan that would withstand the rigors of operating in a tough steel mill environment.”

The plant originally intended to have a contractor build a box to house a fan and have it hinge away from the outside wall of the hot strip mill building where it would be mounted. Although the box and fan would be nearly 50 feet in the air, a swing-out design would allow personnel to work on the fan from the outside of the building using a lift bucket.

Zimpher explained that Aerovent could custom design a fan to meet their needs. “We can furnish a mounting adapter with a hinged door that will allow access to the fan,” Zimpher said. “The plant said ‘That’s exactly what we want.’”

 After discussing the ventilation, installation, and fan requirements, Zimpher concluded that the plant needed a custom-designed swing-out panel fan with a wall box, inlet screen, and outlet damper. The custom design required the damper to be mounted outside the mounting adapter, which needed to be split into two pieces and hinged to allow access. The damper would be located on the outside of the assembly and the fan was designed to be mounted rigidly inside the wall mounted section of the hinged mounting adapter. The entire assembly would be installed about 50 feet high through the side of the building.

 The fan was to have few removable parts. However, those parts had to be removable from the outside of the building so the main fan components could be easily accessed using a lift bucket. Other fan requirements included a direct drive motor, heavy duty construction, corrosion resistance, and easy installation.

Solution

Zimpher Kyser Inc. supplied a DDPRC direct-drive, reverse-construction panel fan from Aerovent. “Reverse construction means that the propeller is mounted to the outside of the fan assembly,” Zimpher said. “The main reason for choosing this fan is access. They can work on this fan from outside the building. When they lost motors on the roof ventilators, the only way they could get them off the roof was by helicopter and that was very expensive.”

The 48-inch 5HP fan exhausts 35,000 CFM of air at 0.125-inch static pressure, which allows for the mounting adapter and louvers. The heavy duty fan has a solid cast aluminum propeller, and a corrosion resistant epoxy coating to withstand the harsh conditions.

Results & Benefits

Aerovent provided a custom-designed swing-out panel fan to help ventilate the steel plant’s hot strip mill building. Zimpher worked with the company and their installing contractor to custom design a fan solution to satisfy the ventilation requirements while overcoming the accessibility issue. The plant can now access the new fan to perform preventive maintenance or make repairs if they become necessary.

In addition to reliability, easy access, and ease of installation, the company wanted a fan that’s easy to maintain. “They also wanted the fan to have a direct drive configuration,” Zimpher said. “There’s no belt, sheaves, or extra bearings to worry about with this fan. Combining that with the all-welded solid construction and solid cast aluminum propeller makes this the best type of fan for this application.”

Zimpher recognized the need for what the plant wanted to accomplish. And Aerovent was open to building what the customer needed. “Our biggest advantage over other fan companies is that Aerovent is open to building fans for special applications,” said Zimpher. “Being adaptable to customers’ needs pays dividends later on. People appreciate that.”

The plant is very happy with the fan from Aerovent because it’s the right fan for the application and they have ordered several more. The plan is to install nearly 40 fans like this one to accomplish the required amount of ventilation needed for this application. “Aerovent is one of the only fan companies that would say, ‘Yes, we can build the mounting adapter like that. We can do that.’ They designed it within a couple of weeks without having done anything like that before. Aerovent pulled it off. Many other fan companies don’t do specials anymore. That’s our ace in the hole. Aerovent is willing to consider specials. It’s their niche it always has been.”