The cost of owning, operating, and maintaining vacuum equipment increases every year. This is, in part, because the equipment hasn’t seen much in the way of technological advancements in the past four decades.

That’s a long time given that the average food plant can contain hundreds of vacuum pumps. They’re commonly used on tumblers to lower pressure in the container, with vacuum stuffers to ensure no air gets into products as they’re packed into a skin or casing, and on vacuum packaging machines to improve shelf life.

Fortunately, the R&D stagnation is coming to an end. Leybold, the oldest vacuum pump company in the world (169 years and counting!), is bringing new vacuum pump technology to the food industry that can dramatically cut down on costs by reducing energy consumption and maintenance requirements, improving production uptime, and enhancing cleanability.

To learn more about the application of dry screw pumps in the food industry, we spoke with Jim Hupp, the Product Sales Development Manager for Leybold USA.  

A solution for the rising costs of operation and maintenance

“The number of vacuum pumps in a food plant adds up very quickly,” Hupp says. “And as they do, so do the costs of operating and servicing all that equipment.”

Hupp estimates that over 90% of all the vacuum pumps used in food processing and packaging applications use the same pump technology that's been around for the last 40 years. This technology consists of oil sealed, rotary vane vacuum pumps and water sealed liquid ring vacuum pumps. “Oil sealed rotary vane  pumps have a limited life and require routine maintenance,” Hupp says. “Depending on the maintenance, they may need to be repaired as often as once a year, even sooner in some cases.” Water sealed pumps can have high operating cost due to the high usage of water, and their performance can vary seasonally depending on the temperature of the incoming water supply.

Dry screw pumps provide a solution for taming these escalating costs.

Unlike traditional pumping systems, dry screw pumps don’t require oil or water to create a vacuum. They work with two internal screws, or rotors, in the pump housing that rotate, so the inside of the pump cavity remains dry. Liquid-based vacuums can draw water vapor or food materials into the pump, leading to downtime and costly repairs. “The dry screw technology will move product through the pump and out the exhaust, so you don't have the maintenance and repair cost associated with the older technology.”

Saving valuable energy

Another way dry screw pumps cut costs is through reduced energy consumption. “Every pump has a motor on it, and every pump requires energy and power to run it,” Hupp says.

Oil sealed and liquid ring pumps generally require larger horsepower motors compared to dry screw pumps, which means they also require more energy to operate. Dry screw technology doesn’t have to move water or oil, and that alone makes it more energy efficient than its predecessors. “Also, many dry screw pumps are run with variable frequency drives. When the pumps are in an idle mode, you're able to slow the pumps down, which reduces consumed energy. You can speed them back up again when you need to.”

Hupp says that it’s not just the pumps themselves that use energy. Traditional pumps are usually air-cooled, which means they radiate heat. Production areas are typically kept at roughly 40°F. So, while pumps are continually producing and radiating heat, the facility’s HVAC system has to work even harder to maintain proper production area temperatures.

Dry screw pumps are usually water-cooled. “The advantage of a water-cooled pump is it removes the heat compression from the vacuum pump,” Hupp explains. “The heat is carried away through the water.” This means it’s not releasing all that heat into the room and overworking the cooling system.

To increase the energy efficiency even further, Leybold developed an energy-saver mode.

Hupp says they were able to reduce energy consumption drastically on the dry screw pumps by using a mechanism that lowers the consumed energy significantly when pumps are in an idle mode or running on processes where pressure levels are below 5 torr. This is a new feature, one that’s not possible with oil and water sealed pumps. “We're already the most energy efficient to start with,” Hupp says, “and we found a way to improve our energy efficiency by another 50% in certain applications.”

Addressing cleaning and sanitation issues

It’s always a win for food manufacturers when they can clean their equipment with minimal downtime. Unfortunately, this hasn’t always been the case with vacuum pumps.

Employees have to be vigilant when it comes to equipment components that are welcoming environments for bacteria. Hupp says oil and water sealed pumps, pull in and accumulate food materials over time. This creates not only problems with functionality, but also the potential for contamination. And if a problem arises with one of these traditional pumps, the company typically has to pull it off the production line, send it out for disassembly and diagnosis, and wait for its repair and return.

To enable easier and, most importantly, on-site cleaning, Leybold gave one of its dry screw pumps a cantilever design. “If you do pull product into the pump,” Hupp says, “you can take the pump housing off, expose the inside of the pump, manually clean it, and put the housing back on. It will be fully operational again.” This whole process takes less than an hour and is straightforward enough for the plant’s maintenance employees to handle, rather than having to send the equipment out for repair. “That's a big advantage in the process industry, due to the high potential of product carryover in the vacuum pumps.”

Dry screws pumps may soon inspire sanitary designs and procedures that have not been possible previously. Hupp notes that there are growing concerns about the piping between the pump and the food processing equipment because the piping on traditional pumps can’t be sanitized without risking damage to the pump. “With the dry technology,” Hupp says, “some people see an avenue that will allow them to sanitize vacuum lines and pumps. As dry pump technology becomes prevalent in the food industry, I think they'll start developing new sanitary procedures for this equipment.”

Ahead of the competition

Leybold isn’t the only company manufacturing dry screw pumps, but they are the first to bring this equipment to the food industry. So far, the results have been very promising. “What we're finding is that customers are getting the same or better performance that they had with the old technology, but they're doing it with less horsepower, fewer pumps, and lower cost.” Hupp says.

Hupp is looking forward to sharing these findings with PROCESS EXPO attendees later this year. “We keep coming back to PROCESS EXPO because of the wide variety of people we get to interact with. For us, it’s exciting to talk to processors and share new technologies, especially when those technologies can help them address their current concerns.”

If you’re interested in improving your efficiency and reducing the total cost of ownership of your vacuum pumps, stop by Booth #4068 to talk with Hupp and the Leybold team.