Industrial Utility Efficiency

Expert Viewpoint: Howden America on the Importance of Blower Control Technology

One of the most exciting technologies impacting the ability of end-users to optimize blowers at their wastewater treatment plants and manufacturing operations is controls. Blower & Vacuum Best Practices interviewed Tim Hilgart, of Howden America, to get his perspective on blower controls technology and its application.

The value of controls technology to optimize blowers is only expected to increase as wastewater treatment plants and industrial operations alike look to improve production and save energy. Shown are Howden KA Single-stage turbo blowers at a major wastewater treatment plant.


Good morning! Tell us about your professional background and experience with blower control technology.

At Howden, I lead the Environmental Sales Team for North America, which covers the United States, Canada and Mexico. Environmental Sales is how we describe the side of the business involving blowers and low-pressure, high-volume air compressors in the wastewater industry, as well as various marine applications. We have another division dedicated to industrial blowers used in industrial applications, such those found in cement manufacturing, mining, and food and beverage applications among others.


Tim Hilgart

Tim Hilgart, Digital Solutions Engineer, Howden America.

I earned a Bachelor of Science Degree in Electrical and Computer Engineering from Marquette University in 1996. Since then, blower control technology has been an integral part of my career. This includes my first job out of college at Energy Strategies Corp. (ESCOR), which is  a company involved in advanced aeration controls. I later joined General Electric’s Industrial Air and Gas Technology business unit. At both companies, I spent considerable time focused on  PLC and HMI programming for blowers and various applications.


Describe a basic blower control system used in today’s treatment plants and factories.

Fundamentally, a typical blower control system is comprised of controllers used on individual blowers to modulate the airflow to the system, while a centralized Master Control Panel integrates the blowers and ensures they work to together to achieve optimum energy efficiency based on the processes involved. 

Realistically, there are three hardware and control strategies for blowers and air compressors.

The first is protection-only controls where you’re basically making sure the blower is operating safely, and if it gets out of stable range, shuts it down to protect it. The second strategy is what we call “process controls” in which we vary the speed and/or change the guide vane parameters to change the flow and pressure output of the machine. The third leg is tying the blowers in with the master control, which coordinates all blower operations, including lead/lag swapping, total volume, total pressure output, and splitting the load and integrating it into larger process control systems.

We don’t see a lot of blower packages sold with the master controls included. Instead, it’s mostly the blower being sent out with its own control panel and then integrated into the master controller, whether it’s at a treatment plant or industrial facility. Industrial customers have been integrating the blower control and integration into their Distributed Control Systems  for the better part of a decade and we are starting to see that carry over to the environmental market as well.  We’re always willing to work with the customer as a trusted advisor to accomplish their goals.


Who typically sets up and configures the blower control system? 

It’s different for the municipal wastewater treatment market than it is with factories.

A project bid for treatment plants usually includes separate sections for the blower and controls, which then opens up the controls piece of it to systems integrators who are doing the integration of the blower with the overall SCADA system. Systems integrators are okay with process control coordination, but they usually rely on us, as the manufacturer, to handle the protection part of it. They don’t want to take responsibility for a large piece of equipment like a blower. Many consulting engineers would like to see the manufacturer handle it all and take on the responsibility for controls from A to Z, but that’s typically not how it works, due to need for competitive bidding.

In the industrial side, we’re seeing more end-users taking on responsibility for all aspects of the blower controls. As an example, we work with a glass factory and they’ve got a full-time staff of control engineers running around the plant making sure the equipment is all coordinated with the plant’s master control system. Manufacturing operations are really taking on more self-responsibility for system integration.


How would you describe the comfort level of those who put blower controls into practice?

About 15 years ago everyone kind of thought control technology was voodoo and they really didn’t know what was happening with it, but it somehow worked. End-users and operators didn’t even want to touch a blower control panel. But the level of participation in the technology and the acceptance of automated controls has grown.

While the protection-only controls are usually hard wired, customers often make changes themselves to fine-tune the system as far as process control and we’ll partner with them on those types of things. We’re at the point now where operators and end-users anticipate using controls. In fact, I sometimes have to spend more time explaining how to change out an airflow transmitter than changing the settings on the control systems, which is exactly the opposite of how it was when the industry first began to adopt blower control technology.


What factors are driving this increase in acceptance of the technology?

I think it’s kind of a reflection of society with everyone having smartphones and tablets. It’s made everyone more comfortable with seeing this stuff.

Another trend we’re seeing is end-users and consulting engineers saying, “Yeah, we see how all of these different types of blower technologies work, but I also really care about who’s supplying it. Who’s doing the actual packaging of it? Who’s going to support it?” It’s putting more emphasis on the need for support from blower manufacturers and distributors.


Are there other factors driving the need for support in the field?

The short answer is, yes. While controls knowledge is expanding the mechanical knowledge is slowing down, particularly at treatment plants. A lot of those facilities don’t have the mechanical operators they used to have, which is a major concern for the field since nearly half of the professionals in the industry are retiring. You’re losing a lot of guys with an electrical background who can fix a starter, let alone a Variable Frequency Drive (VFD). I think the quality of the operations have improved on the process side, but the mechanical capabilities of the plant staffing has started to regress a little.

We don’t see this as much of this on the industrial side of blower applications. The industrial segment still has the solid base of mechanical talent in place. You still see lot of mechanical engineers at factories versus treatment plants.

I think another concern from the end-user’s perspective as far as machines has to do with them getting bombarded with efficiency, reliability and total cost of ownership and everybody’s got the best solution for it, whether it’s rotary screw blowers, geared blowers, or high-speed centrifugal technology, etc. Their question is, “How do we know what’s best and who’s going to prove it for us?”

There isn’t an easy answer. At Howden we’re trying to take on that challenge by providing the various technologies and saying, “Here’s what’s good in this application and this is what’s good over in this other application and these are the trades offs.” I think the market is looking for honesty. This is what ASME PTC 13 is designed to do. It should help level the playing field.

"Howden EasyAir"

Shown is Howden’s EasyAir™ Turbo Blower, which is a fully integrated and compact single-stage blower for use in the wastewater treatment industry.


What does a higher comfortable level with blower controls mean as far as the Internet of Things (IoT) and Industry 4.0?

To answer that question, it’s important to define these terms.

IoT describes the connection of devices and equipment in factories and the ability to transfer information over a network. IoT is about making things Internet-ready and being able to connect through the Internet. It’s an enabling pillar that supports Industry 4.0.

Industry 4.0, which is also referred to as Factory 4.0., is about the way in which you take the information now available and use it. Everybody has servers full of equipment and operational data they’ve been collecting and storing over the years, whether the information is stored on a hard drive, or to a server maintained by a cloud provider. The question is, “What do you do with it?”

I think most everyone is aware of IoT but only about half of the users of blowers and air compressors are out there doing things with the data as part of Industry 4.0.


So how can end-users put data related to blower operation to good use?

You want to be proactive rather than reactive, which is where the manufacturer comes in. I say that because we have the knowledge of knowing how that equipment is supposed to be running.

A buzzword now used is “digital twin,” which describes the ability of the manufacturer to run a theoretical blower or air compressor on its server that matches the machine at the treatment plant or factory. As a manufacturer we can see how the customer is operating it and we know what the output of the blower should be compared to what it’s actually doing. That lets us go back to the customer and work toward predictive maintenance rather than reactive maintenance, allowing them more uptime for their equipment. It also allows us to optimize the efficiency of their system so they’re spending less money on how they’re running it.


What are you seeing as far as treatment plants and factories having the manufacturer involved in leveraging equipment data?

You don’t always see blowers being applied in the right way at treatment plants, or not operating as efficiently as they could operate process-wise. As the trust between the manufacturer and treatment facilities develop it will allow companies like Howden to provide more guidance to plant operators.

The industrial side is a different story since it’s about maximizing the efficiency of the machine to increase profit. They see the value of not only having the data but monitoring it and knowing how to run the data to their advantage. We’re very busy from an industrial standpoint when it comes to the Industry 4.0 world and implementing our data driven advantages. Municipal wastewater treatment plants are typically more conservative and slower to adopt new technologies, but when they do, they tend to dive deeper than other industrial segments.


Is there anything getting in the way of having blower manufacturers assist with Industry 4.0?

Data security has caused the most headaches for users as far as protecting stored data and sharing it.

It can be a little more difficult for wastewater treatment plants that discharge into federal waters because then they feel they have to follow Homeland Security procedures. It’s less of an issue with industrial manufacturers.

But whether it’s a treatment plant or a factory, there are building blocks that can be put in place to make it very secure. Then there’s the idea of how you do it. We only do one-way communication. By that I mean we only want to gather data; we don’t send it back into the system. We’re just taking the data the plant or factory gives us to analyze. It allows security to be a lot better.

We also don’t want to go in and make changes to the blower operation. Instead, we go back to the plant and say things like, “Here’s what we’re looking at. Here’s the end of the month summary. Your blowers are getting maxed out at night, if you change your recycle pump to do this or that you could save this much energy.” We let them decide on the most responsible action. It becomes us partnering with them on things they can try and helping them make incremental improvements.


How do you see the future of blower operation unfolding at treatment plants and factories?

I think we’re going to stop seeing the use only one blower technology. More and more operations are implementing mixed technologies. We’ve got a wastewater treatment plant right now running two geared turbo blowers, six multi-stage centrifugal blowers and two rotary blowers all on the same header. They run the blowers interchangeably. I think a wider mix of blower technologies is where the world is going.

I wouldn’t be surprised if future success is based on how well you can operate different technologies at the same plant. That’s only going to increase the importance of the controls piece of it.


Thank you for these insights.


For more information, contact Tim Hilgart, email:, or visit

All photos courtesy of Howden.

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