Developing devices for specific needs
With an instrument focused on removing matter from a space, the vacuum-pump industry sure creates a lot of “matter,” in terms of different devices. Vacuum pumps come in so many varieties that, well, it’s a regular vacuum-pump jungle out there. Most laboratory pumps create a vacuum with a rotary-vane or diaphragm mechanism. But some users care more about a pump’s use of oil or lack of it. Maybe it matters more to a user that a pump resists chemicals. Companies also make some vacuum pumps for industrial applications and others for labs. The options go on and on.
Despite that diversity, some trends exist in the technology. Sam Lanasa, one of the owners at New Star Environmental (Roswell, GA), says, “One trend is creating stronger pumps. If you’re using a tighter filter that creates more of a pressure drop across it, the pump needs to be stronger to maintain the flow.” He adds, “Many applications are centered on a particular flow rate and maintaining it.”
Among lab vacuum pumps, in particular, noise also matters. Lanasa says, “Our Rocker 300 operates at about 50 decibels, and that’s very quiet.” Even normal conversation is louder, reaching 60 decibels or so.
Selecting a system
Not that long ago, the options for vacuum systems seemed pretty generic. Lots of labs generated vacuums with waterjet devices, and some still do—despite the huge environmental and financial cost. Many institutions still provide central-vacuum systems. In some cases, though, a specialized system makes more sense.
A cell- or tissue-culture lab is a great example of a lab that can benefit from specialized vacuum options. “Many labs cobble together an aspiration system with side-arm flasks and tubes,” says Peter Coffey, vice president of marketing at VACUUBRAND (Essex, CT).
I’ve done that myself. In the early 1980s, I worked in a tissue-culture lab. To replace the media that sustained the cells, I used a vacuum “system” that consisted of a pipette connected by a rubber hose to an Erlenmeyer vacuum flask, which was connected to a central-vacuum line. I controlled the level of vacuum by how much I opened the valve on the central line, and that control would be called coarse at best. When you can’t control the intensity of the vacuum, it’s difficult to draw off the media without taking the cells with it. And what do you do if your lab does not have a central vacuum?
To solve that problem, VACUUBRAND developed its BVC integrated aspiration stations. “These include a vacuum pump designed for cell- and tissue-culture applications, plus a biofilter, pressure controls, and an autoclavable flask,” Coffey explains. “And the entire system is resistant to the bleach that is used so often as a disinfectant.”
Past a pump’s prime
A vacuum pump makes it pretty clear when it should be replaced. “It starts humming and gets hot,” Lanasa says. “It won’t hold the flow.”
Lab managers who take care of pumps—changing filters on schedule, for example—should get years of use from their pumps. Lanasa says, “Out of about 5,000 Rocker 300s that we’ve sold, we’ve probably had 10 returned and usually for misapplications.” He adds, “If you run a vacuum pump at its specifications, it will run.”
For additional resources on Vacuum Pumps, including useful articles and a list of manufacturers, visit www.labmanager.com/vacuum-pumps