Industrial Utility Efficiency    

Tuthill Tackles Demanding Industrial Vacuum Applications

Thanks to branding, people recognize popular products and the companies behind them. Ford manufactures automobiles. Hershey makes chocolate. Dogfish Head brews some really great beer. In each example, the company and the product are nearly synonymous.

But what about the other companies that help produce those consumer goods?

There are countless tangential companies that play a key role in the multitude of processes within large manufacturing operations. Without these companies and the equipment they provide, many products would never hit the shelf. 

Tuthill Logo

  
Keith Webb, Application Engineering Manager at Tuthill Vacuum Keith Webb, Application Engineering Manager at Tuthill Vacuum & Blower Systems

 

   

Tuthill Vacuum & Blower Systems is one such company, and, despite its diverse list of high-profile clientele (none of which are mentioned here), it remains largely out of view. Tuthill manufactures industrial equipment that enables companies to mass-produce the products that people know — whether it’s an airplane, a piece of produce, or your favorite beer.

We were fortunate enough to speak with Keith Webb, the Application Engineering Manager at Tuthill, to learn about the company and its manufacturing equipment. During our discussion, we talked about the company’s blower and vacuum technologies, common markets and applications, and Tuthill’s custom-engineering capabilities. Webb even touched on some trends in energy management regarding blower and vacuum systems.

 

Blowers vs. Vacuum Pumps

The manufacturing technology that helps produce and process even the most common products can be very complex, and industrial vacuum is one of the most complicated. Where air compressors and blowers have objective standards, vacuum remains one of the more obscure, difficult-to-understand manufacturing technologies.

“Uses of vacuum in industrial and chemical process industries is very widely misunderstood even by most engineers,” Webb told us during our interview. “There are few knowledgeable end users of vacuum, and when you talk to someone, you can tell right away whether they have experience in the vacuum industry. So it’s always good to get some education about it out there for engineers who want to understand more.”

Both Webb and David Schardt, Tuthill’s new VP of Engineering, are members of the Compressed Air and Gas Institute (CAGI), one of the organizations currently creating standards for blowers. According to Webb, the blower industry seems to be more normalized when it comes to basic packages. It’s the vacuum side of the business that demands more customized packages.

“In the vacuum world, it gets more exotic. Customers want a variety of different options in the way they control the system,” Webb explained. “The blowers are basically two-lobe rotary or three-lobe rotary blowers, and they vary in seal construction. Then there may be some material construction differences. Technologies on the vacuum side are much more varied, and each has its own pros and cons for each application.”

At Tuthill’s location in Springfield, Missouri, they make an assortment of vacuum equipment in addition to their blower packages. Off the cuff, Webb cited a slew of standard product offerings on the vacuum side, including single-stage liquid ring pumps, two-stage liquid ring pumps, single-stage oil-sealed rotary piston pumps, two-stage piston pumps, dry screw pumps, and oil-sealed rotary vane pumps.

As if that exhaustive list was not enough, Tuthill also offers a line of vacuum boosters to increase flow and provide deeper vacuum levels. Theoretically, those boosters can be paired with any of the aforementioned vacuum pumps.

 

Key Market Segments and Typical Applications

Whether they are using blowers or vacuum pumps, Tuthill’s customers are all engaged in industrial manufacturing of some sort. A typical customer might be an engineering firm, or an engineering group within a large company. Tuthill’s primary markets include the chemical, food processing, pharmaceutical and aerospace industries — just to name a few.

“[Our customers] are all using blowers or vacuum equipment to make something, and so it’s typically a very vital part of their process,” Webb told us. “Reliability is very key. Because if there is no pressure or no vacuum, then production stops.”

Some of the more common processes include distillation, industrial drying and evaporative processes, each of which is done in vacuum. As an example, Webb explained a common food processing application:

“Let’s say you’re trying to dry lettuce after washing. One way to remove the water is to raise the temperature to 212°F at atmospheric pressure,” Webb said. “But no one would want to eat that lettuce afterwards.”

“In order to dry that off, you can reduce the pressure around the liquid and get it down to its saturated vapor pressure, and then add the latent heat,” he continued. “At a given temperature, the saturated vapor pressure of a substance is the pressure at which it is phase equilibrium between the liquid and vapor phases. By adding the latent heat of vaporization (the energy required to change phase), the liquid can change to the vapor phase and be removed from the product. You never actually have to change the temperature of the product in order to drive that moisture off. It’s a very effective method for drying, evaporation and distillation.”

According to Webb, there are tons of products that require this type of process. By adding latent heat and changing the phase, the product remains unaltered.

 

Custom Engineering Capabilities

Tuthill’s diverse clientele base — and the even larger pool of varying applications —creates demand for custom-engineered systems. Because no one facility or process is the same, the engineers at Tuthill adapt their standard products to unique customer needs.

“Our Application Engineers are capable of taking anything blower or vacuum related in pretty much any market, application or industry you can think of, and properly choosing one of our products,” Webb said. “Customers vary in what they want in systemization from one to the next, and that’s what we have the ability to offer here.”

Variations from system to system range from measurement devices to customizations at the PLC level. According to Webb, some customers may have a preference for a certain type of temperature or pressure transmitter, since their personnel are already accustomed to using it. That is accounted for during the quotation process, and the engineers in Webb’s group can incorporate that device in the quote. Other non-standard modifications to systems include additional sensing equipment for automatic shutdown protection and bypass lines to meet various pumping scenarios, among many others.

Before the equipment gets to the customization phase, however, Tuthill exerts a level of control over their product that is uncommon among manufacturers. Save for the bearings and soft seals, the fabrication team at Tuthill machines every part that goes into their blower and vacuum products, giving them complete control over their manufacturing process.

And, because there is not a one-size-fits-all testing requirement, Webb and his team also provide custom testing for vacuum systems. This helps them ensure the electrical and mechanical reliability of the equipment before it ever leaves the building.

 

Massive Vacuum System for Airplane Brake Pad Manufacturing

During our conversation, Webb walked us through several examples of custom-engineered systems that recently moved through Tuthill’s shop. The first was a large booster piston pump system for an aircraft component manufacturer (Figure 1).

Standing about 15 feet in height, the vacuum pumps in this system were designed to service four chemical vapor deposition (CVD) furnaces on an aircraft manufacturing line, providing 10 to 20 torr of vacuum.

 

Photo 1

Figure 1: 4500 cfm (7650 m3/hr) booster/piston system for an aircraft brake pad chemical vapor deposition (CVD) furnace.

 

The CVD process emits various hydrocarbons, along with some relatively toxic and flammable substances. To address those hazards, the systems also include large filtration units, knockout pads upstream for trapping liquid, and demisters.

 

Industrial Vacuum for Extrusion

Another custom vacuum system Webb described was a two-stage booster system designed for an extrusion company (Figure 2). The client makes large extruders for a variety of industries, including plastics, ceramics and food processing. All of their extrusion processes are done in vacuum.

The required vacuum is between 5 and 10 torr for this particular application. The booster, and the liquid ring pump positioned downstream, help to move gases that are liberated during the plastic extrusion process. These include volatile chemicals and some light aromatic gases.

 

Figure 2

Figure 2: 3000 cfm (5100 m3/hr) booster/liquid ring system for plastic extrusion degassing

 

Brewery Requires Vacuum for Degassing Process

The third system Webb discussed was a stainless steel liquid ring system for a “very popular beer manufacturer.” The client, who is undergoing capital expansion, needed four identical systems for gas removal from bottles before the filling process. The operating range for this application is 75 to 100 torr.

 

 Photo 3

Figure 3: All stainless steel liquid ring system for beverage filling process with “clean-in-place” control system

 

As a preventative measure, and to ensure a long product life, the engineers at Tuthill designed the entire liquid ring pump as 316 stainless steel (Figure 3). Additionally, the system was equipped with a knockout tank system and a full sealant recovery system. A ph transmitter enables it to manipulate valve positions based on the ph level in the liquid ring sealant. The system also has interlocking devices, like shutdown switches for high-temperature conditions.

The engineers at Tuthill also incorporated “clean-in-place” controls for the brewery’s system. The controls allow the customer to shut the system down, fill it completely with cleaning liquid, and then open drains to flush it. Once the cleaning procedure is finished, the manufacturer can resume normal operation.

 

Trends in Energy Management

Webb also shared some insights into trends across the blower and vacuum industry. On the blower side, with its larger horsepower requirements (up to 700 hp), de-centralized blower systems are becoming more common. This means that instead of having a single blower trying to supply several demand points that may or may not have a requirement, engineers are starting to use multiple units of smaller sizes to address demand points with the appropriate amount of air.

Manipulating the speed of the blower in order to better match the demand requirement is another practice becoming more common. In less efficient systems, a fixed-speed unit will run constantly, dumping the excess through a relief valve. By adjusting the speed, you can eliminate the artificial demand.

Engineers will also take advantage of soft starts to keep the demand charge of the utility bill down. Instead of hitting units with direct line voltage, leveraging soft starts helps to lessen the demand spike as the unit comes on. Facility management can then ramp the blower up at a more controlled rate.

Another trend Webb discussed involved the use of variable speed drives (VSDs). Customers have started to use VSDs to manipulate blower requirements. They mirror that on the vacuum side by utilizing a vacuum booster upstream. Both, according to Webb, are techniques used as a form of energy management.

 

Energy Management for Vacuum

Because vacuum applications are so varied, managing energy costs in those systems depends on the process. Oftentimes, a vacuum process can run on continuous duty for days at a time, meaning that a batch or cycle may last up to 72 hours. Facility management may start a vacuum pump to pull the system down to a set pressure, and a switch will activate a vacuum booster at that set point.

 To efficiently manage that type of vacuum process, the application engineering team at Tuthill makes sure to appropriately size the booster with a vacuum pump. They then size their loaded power based on the most efficient time to start that unit. According to Webb, that does a couple of things. For starters, you only invest in the capital cost of the motor that you need. Secondly, the life-cycle cost of the unit is less because you use less energy with the lower motor power.

 

Taking Tuthill to a New Level

Tuthill Vacuum & Blower Systems was formed in 2002 after a series of acquisitions and corporate restructuring. Currently, the company is the sole manufacturer of Kinney® vacuum pumps, along with M-D PneumaticsTM rotary blowers and vacuum boosters.

Several recent additions to the Tuthill team have helped to broaden the company’s engineering capabilities. The process began with the hiring of David Schardt, the new VP of Engineering at Tuthill. He then hired two additional engineers, including Wan Zhong, who has a Ph.D. in mechanical engineering, and Shraddha Jayakumar, who has a Master’s degree in mechanical engineering.

Under David’s direction, Tuthill’s team is looking at all existing products to identify opportunities for enhancement in performance and improvements in the manufacturing process. In addition, there are several blower product enhancement projects that are planned to launch later in the year. The engineering team is also focusing on new product development for both the blower packages and dry screw technology.

All of these improvements are poised to help manufacturers produce more goods at lower costs — even though the general public will only see the finished products.

 

For more information, contact Keith Webb, or visit www.tuthillvacuumblower.com

To read more about Blower & Vacuum Technology, visit www.blowervacuumbestpractices.com/technology.