When it comes to acquiring a laboratory vacuum pump, it's crucial to understand that you have numerous options for selecting the ideal vacuum pump for your needs. Vacuum pumps come in a variety of shapes and sizes, each with its own set of displacement limitations and maximum vacuum levels.
There are four main types commonly for vacuum pumps.
Diaphragm Vacuum Pump
Diaphragm Vacuum Pumps are dry pumps that move the air by opening and closing valves in a pulsating pattern. Oil is not required with this setup. The valves are frequently composed of polytetrafluoroethylene, enabling the pump more immune to corrosion inhibitors and vapor degradation.
Although they may be more expensive upfront, they do not consume oil, therefore their service & maintenance expenses are substantially lower than pumps that do. Diaphragm pumps can manage very viscous liquids and a huge spectrum of samples, but their uses are constrained to those that require higher ultimate vacuum levels.
Diaphragm pumps are among the most chemically and corrosion-resistant pump varieties. As a result, these pumps can handle practically any type of sample, including ones made from a variety of solvents and acids, making them an excellent alternative for both evaporation and concentration.
Pros and Cons
Pros:
Rotary Vane Vacuum Pump
Traditional Rotary Vane (RV) Vacuum Pumps are commonly utilized because they are less expensive upfront, lighter than other types, and may be employed for a wide range of applications. Oil is used in RV pumps to guarantee a tight seal, lubricate moving parts, and dissipate heat from the rotors.
Solvents that aren't stuck or regained before entering the RV Laboratory vacuum pump can compress in the pump oil and cause significant damage to the pump's interior. The dissipated vapors must be collected upstream of the RV pump when operating it. To capture these vapors and preserve the pump, condensers or cold traps are typically utilized.
Rotary Vane vacuum pumps, on the other hand, attain deep ultimate vacuum levels and have a large displacement capacity. As a result, they're ideal for freeze-drying. RV pumps are particularly useful for watery samples and solvents with high boiling points, as the vapors are easily contained before reaching the pump.
Common Uses
-
Rotary evaporation
-
Freeze drying
-
Vacuum filtration
Scroll Vacuum Pump
Scroll vacuum pumps condense air and vapors and transport them toward the exhaust using two spiral scrolls. While they may have greater upfront expenses, they have drastically lower lifetime operating costs since they do not use oil and require minimal maintenance.
The scrolls should be replaced every 40,000 hours of use, according to the manufacturer's recommendations. The hydrocarbon-free design eliminates the need for oil, making these pumps environmentally sustainable. Scroll pumps are more efficient at handling water vapor than other types of pumps and produce substantially less noise when in use.
Also because scrolls are constructed of metal, only specimens with acids below 20% are advised, including on chemical- or corrosion-resistant variants. Scroll pumps have greater movement capacity and can achieve deeper maximal vacuum values than diaphragm pumps.
Finally, one of the most crucial things to understand about vacuum pumps, regardless of the sort of pump you're using, is that whatever goes into the pump will come out! When samples contain potentially dangerous compounds, you must take further care even using filters. When exposed to hazardous specimens, you must use a fume hood.
