The Situation and Opportunity
Some extremely demanding applications really test the limits of high-performance blowers. The testing labs at Donaldson Filtration Solutions pushed the limits of what is possible in a vacuum pressure application challenged by extremely high particulate, high temperature and high moisture.
Donaldson is known for its solutions for a variety of industry sectors, including aerospace, agriculture, construction, food and beverage, manufacturing and transportation.
In 2019, Donaldson developed a sampling process to evaluate the life and efficiency of different flat-sheet filter media for their industrial combustion aerosol filtration systems.
“We needed a blower that could reliably and consistently pull at least 40” of vacuum through the filter media, despite the harsh environment that involved aerosol with very high moisture — sometimes with liquid water migrating into the blower — along with high temperature, corrosive gasses and combustion particulate,” explained Eliott Jorgensen, Donaldson senior engineer.
He chose an off-the-shelf Windjammer brushless DC blower from Bison.
“The Windjammer is a high-performance and reliable solution, at a reasonable cost. It gave us the ability to precisely control airflow to meet our testing protocols along with outputs for our data logging.”
However, the harsh environment eventually overwhelmed the blower.
“We called the Bison sales office, and they immediately connected us to their applications engineering team, which led to a remarkable collaboration,” said Jorgensen. “We saw this challenge as the ultimate stress test for a blower, and we worked together with Bison engineers, upgrading the blower and incorporating some state-of-the-art innovations, to engineer a solution that reliably meets our needs.”
The Solution
The complete solution necessitated a comprehensive, multifaceted approach, from the overall design of the motor and blower assembly to the materials of the various components to the mounting of the blower housing itself.
Bison recommended that Donaldson upgrade from a standard Windjammer 5.7" 2-stage Brushless Blower to the Windjammer Pro 5.7" 3-stage version, with some options for maximum performance and reliability.
Better Protection
Ideally, with electric blowers, the air should be dry, clean and filtered. In this application, the very wet air causes corrosion in the rotating parts and can wash out the grease that lubricates the bearings.
Therefore, the enhanced system incorporated corrosion-resistant materials and coatings.
- Stainless steel shaft for corrosion resistance
- Sealed bearings specially designed to prevent grease washout and contamination
- Silicone coating of control board for moisture protection
Higher Performance
Another important mitigation strategy was the addition of pre-filtering to reduce the moisture and particulate that enters the blower. The pre-filtering significantly increased airflow impedance. Therefore, more vacuum pressure was required, necessitating higher performance of the blower. This was accomplished in two ways.
First, Donaldson upgraded from a 2-stage Windjammer to a 3-stage version, which provided higher performance.
Better Cooling
The other improvement to performance came from upgrading to the Windjammer Pro to take advantage of the Pro version’s innovative design, which dramatically enhances cooling. Thermal management is the main limiting factor in restricting the performance of electric blowers.
In the development of the Windjammer Pro, Bison rethought the whole cooling process, implementing a system architecture called “reverse cooling.” Instead of the traditional design that locates the cooling air intake next to the hot motor, this new approach uses the fan impeller to draw in cooler ambient air.
Like all bypass blowers, the cooling air is isolated from the air flowing through the blower. But what is special about the reverse cooling in the Windjammer Pro is that the cool air washes over the electronics board, cooling it, before it is pulled through the motor and discharged.
This improved cooling method results in being able to drive high performance, and the lower temperatures increase the life of the brushless motors.
Custom Mounting
All these improvements came from upgrading to the Pro and 3-stage version of the Windjammer and incorporating special features such as the sealed bearings, stainless steel components and silicone-coated control board. The collaboration between the Donaldson and Bison teams also led to one additional improvement that was external to the blower itself: the mounting system.
The application engineers at Bison identified that the original mounting method was placing stress on the blower housing, hindering the rotation of the fan impeller. Bison proposed an alternative mounting configuration, which was fabricated and installed by the Donaldson team, resolving the issue.
Inspiration – What’s Next?
"Our collaboration has proven to be incredibly rewarding for both parties," said Jorgensen. "Donaldson's ability to build a reliable testing capability has been critical to our business, while Bison's deep understanding of our demanding requirements has contributed to their ability to design reliable solutions for their customers' most challenging operating conditions. Together, we have created a mutually beneficial partnership that has paved the way for continuous growth and success.”
Results
Jorgensen appreciated Bison’s commitment to Donaldson’s success.
“They even overnighted an upgraded blower to us so that we could keep our testing on track. Their commitment to our success and the reliability of their products enabled us to complete our testing process on schedule, in time to meet the high customer demand for the medias under development.
“Equally important, the high performance and reliability allow us to perform high-quality tests, evaluating how well our product can perform when pushed to their limits, under long & uninterrupted test cycles” added Jorgensen.
Bison, Donaldson Filtration Solutions
