53668_LM_Vacuum Pumps_eBOOK_JL V1 (1)
? Questions to Ask When Buying a Vacuum Pump
? Picking the Right Vacuum Pump for Today and Tomorrow
? Ultra-High Vacuum and Precision in Measurement
? The Benefits of Automated Vacuum Pumps
? Vacuum Pumps to Replace Your Water Aspirator
? Simple Tips to Keep Your Lab Vacuum Pump Running at Its Best
VACUUM PUMP
RESOURCE GUIDE
Questions to Ask When Buying a Vacuum Pump
There are many different types of vacuum pumps to choose from, including rotary vane, dry diaphragm, hybrid, dry scroll, and turbomolecular pumps
by Lab Manager
Purchasing Tip
Choosing the appropriate vacuum pump for the application is essential and prevents
damage later on. Some applications require extremely deep vacuum (10-3 to 10-9 mbars) necessitating a diffusion pump, ion pump, or turbomolecular pump. For applications that require standard pressures from 200-10-3 mbars, rotary vane, dry scroll, and diaphragm pumps are good options
Vacuum pumps are suitable for a wide range of applications, including aspiration, freeze drying, rotary evaporation, solvent degassing, tissue culture, and numerous others. There are many different types of vacuum pumps to choose from, including rotary vane, dry diaphragm, hybrid, dry scroll, and turbomolecular pumps. Vacuum pump technology is also becoming more environmentally friendly, with many oil-free and energy efficient options. Over the past 25 years, ven-
dors have made significant improvements to vacuum pumps with automated vacuum pumps providing more benefits and features to accommodate the diverse needs of research and industrial laboratories alike.
7 Questions to Ask When Buying a Vacuum Pump:
What depth of vacuum is required for the intended appli- cations? There are many options for low, medium, high, and even ultra-high vacuum.
What is the pumping capacity at the intend- ed vacuum level?
Is a dry (oil-free) pump suitable? They do not require oil changes and have lower overall maintenance costs.
What types of solvents will be used? Will the pump re- quire a corrosion-resistant flow path?
Are any other supplies or accessories required?
How much noise does the vacuum pump generate?
What are the ongoing costs of operation (maintenance costs, energy consumption)?
Vacuum Pump Resource Guide
Maintenance Tip
Vacuum pumps may be exposed to organic solvents, water vapors, acids, and particulate matter that can cause damage. Using a vacuum pump inlet trap can capture these and other contaminants before they enter the pump. A vacuum inlet trap with replaceable media can absorb organic solvent vapors, neutralize acids, or remove particulates or oils, and some vendors offer transparent trap housing so users can visually inspect the media
Vacuum Pump Resource Guide
Picking the Right Vacuum Pump for Today and Tomorrow
There are many options for scientists requiring a vacuum for their applications, and it’s a more complicated process to pick the best vacuum pump for a lab.
by Mike May
Scientists started using some form of vacuum centuries ago. This technology has evolved extensively since Arabic
engineer Al-Jazari invented the suction pump (a predecessor to the vacuum pump) in 1206. As a result, there are many op- tions for scientists requiring a vacuum for their applications, and it’s a more complicated process to pick the best vacuum pump for a lab.
Selecting the correct type of vacuum pump is a challenge. If the pump isn’t big enough it will won’t be able to perform at the level needed for the required results. If the pump is
over-powered, it will be too expensive and possibly too pow- erful for your needs.
Rotary evaporation, for example, depends on a pump that provides optimal flow for the system volume and provides the depth of vacuum that is appropriate for the vapor pressure of the solvents being used. If it is under-sized, it won’t create the
vacuum quickly enough or it simply won’t be strong enough to do the job. If the pump is over-sized, it can cause bumping or you can lose samples.
Filtration applications also depend on the right pump size. A smaller pump than recommended will take too long to func- tion and there may be too little vacuum depth to pull out the liquid from the particulate fraction. If the pump is too strong, filter papers can be torn, ruining the entire process.
Futuristic features
Scientists can consider some options that go beyond a typical vacuum pump. Instead of putting pumps everywhere vacuum is needed, for example, a lab can install a modular system.
Here, a single vacuum pump serves more than one worksta- tion in a lab, similar to a vacuum system in a woodworking shop. The modular approach can significantly reduce the energy that a lab uses for creating vacuums.
Other vacuum pump features are also changing. Newer pumps will be equipped with DC motors, which are more robust, energy efficient, quiet, and have better control over the speed of the vacuum process.
For any kind of vacuum pump, the device must meet the needs of the expected applications. To match up your application with a pump, call in an expert or use an online selection tool.
From Al-Jazari’s 13th century suction pump to the vacuum devices of tomorrow, scientists and engineers keep developing new ways to reduce the pressure in a space. For a lab running multiple, similar applications, a modular approach can be an energy-saving option. If a lab runs a variety of processes, it might need more than one vacuum pump. Plus, older pumps could be replaced to benefit from technological advances.
Surprisingly, it takes a lot of thinking to create nothing.
Vacuum Pump Resource Guide
41t
Ultra-High Vacuum and Precision in Measurement
Ultra-high vacuum replicates conditions some- where between the stratosphere and the most immediate reaches of outer space
by Brandoch Cook
Ultra-high vacuum (UHV) systems are essential tools for research- ers and engineers to achieve extremely low pressures in contained environments. They are powerful enough to accurately measure and alter the smallest semiconductors, or to unravel some of the mysteries of the vastness of space-time. Units of pressure can be as confusing as units of British currency. If you live at sea level, you can reasonably assume a pressure of roughly one atmosphere, unless you decide to climb a mountain, or the weather turns foul. One atmosphere cor- responds to 760 millimeters of mercury (mmHg), a unit your doctor uses when recording blood pressure. Scientific and engineering litera- ture regularly report pressures in Torr, which are roughly equivalent to mmHg, although the international standard (SI) unit is the Pascal (Pa). For every Torr there are 133.3 Pa, so that one atmosphere equals about 101,300 Pa, which is also 1013 millibar (mbar). For Americans filling the tires of your minivans, this is also about 14.7 pounds per square inch, or a little less than half of what you need. Do you follow?
If you dive in the ocean, the pressure increases one additional atmo- sphere for about every 10 meters you descend. Conversely, in the long line to reach Mount Everest’s death zone, the atmospheric pressure drops to less than 20 percent of what it was at sea level, a precipitous decline related to a molecular gradient in which the majority of
mass in Earth’s atmosphere occupies the bottom few kilometers of it. Pressure trends more slowly toward an asymptotic lower limit within the stratosphere. Gas molecules become much more widely dispersed, and hence less likely to collide.
Ultra-high vacuum replicates conditions somewhere between the stratosphere and the most immediate reaches of outer space, achiev- ing pressures in the range of 10-7 to 10-12 Pa. Reaching pressures this low is necessarily a stepwise process. First, the receiving chamber has to be baked at high temperature, and so is most often made of high-quality stainless steel, or of alloys that promote the exclusion of gases. A rough vacuum obtains 10-3 Pa, then a turbo molecular pump
reaches about 10-8 Pa. In the final step, a specialized pump with metal- lic seals and gaskets and a dedicated gauge brings it to its target. Like dust in a seemingly empty room, under ordinary high vacuum, resid- ual gases will settle on chamber surfaces in a monolayer in millisec- onds. Under UHV, monolayer deposition takes days, with the hypo- thetical remaining molecules needing to travel about 50 kilometers to find each other. This becomes very important for multimillion-dollar particle physics experiments that might best be described as quantum existentialism, which depend greatly on the predictability of the path of a proton or ion beam through a long, sealed chamber. A lot is riding on ensuring the beam is not scattered by remnant gases.
In the comparatively humble laboratory space, UHV is broadly applicable to many fields of measurement and materials science. Notable among these are various iterations of electron and atomic force microscopy, and the production and manipulation of nanoscale constructions, for instance in the development of thin film-based semiconductors for high-fidelity electronics. The combination of these fields enables the alteration of graphene- or transition met-
al-based two-dimensional nanomaterials, while characterizing those changes at the atomic level using transmission electron microscopy. Microscope companies offer transmission electron microscope platforms, however the upgrade to UHV requires customization with specialized pumps and gauges. Additionally, there are a wealth of con- tractors that can customize UHV builds to the ideal specifications of a given research goal.
Vacuum Pump Resource Guide
The Benefits of Automated
Vacuum Pumps
by by Mike May and Ajay Manuel, PhD
Vacuum pumps play a role in many lab applications, and sometimes it helps to automatically control this piece of equipment. Applications that involve separating components of a mixture in a precise and repeatable way are good candi- dates for automatically controlled pumps.
One of the most common applications of automatically controlled vacuum pumps is rotary evaporation. They are also handy with distillation columns, fluid aspiration, and vacuum ovens.
Improving efficiency
Adding automation delivers many advantages. Using a rotavap, oven, or distillation column with an automatically controlled vacuum pump gives you the ability to evaporate one component at a time. This can maximize yields while minimizing process times. The advantages extend to a range of applications. With fluid aspiration used with cell cul- ture, for instance, controlling the vacuum keeps the suction consistent when changing media. Automatic control can help prevent aspiration of low adherent cells that can be lost if too much suction is applied.
Environment
Water aspirators are lacking when it comes to environmental impact. Intense use of water is a major concern with water
aspiration processes. Daily moderate use of an water aspi- rator device can waste an estimated 50,000 gallons of water per year. As such, water aspiration has become subject to increasing regulation. Water aspiration also leads to water contamination due to drawing up volatile solvents. Altogether, water aspirators leave a significant environmental footprint, especially in terms of wasted water and pollution.
Features to find
In looking for an automatic controller for an existing vac- uum pump, the first priority is compatibility. The material in the controller and the flow path need to be compatible. The controller must also match the required parameters of an application, such as the required level of vacuum and the pump’s flow.
Then a user must decide between a two-point controller, which is basically on or off, or an adaptive controller, which adjusts the speed of the pump to match the current needs of an application. It is important to note that an adaptive
controller only works with a speed-controllable pump. A two- point controller is a little older technology and therefore less expensive. With rotary evaporation, for example, an adaptive controller prevents bumping, or violent boiling. Bumping can waste some of the sample.
As with other equipment in a lab, scientists want a vacuum pump to be easy to use. Ideally, you want a pump that just requires you to press the start button and then runs your pro- cess to completion. You don’t want a controller that requires
a complicated setup or programming procedure or that needs to be supervised during the process to be sure it is advancing as expected.
Vacuum Pump Resource Guide
Vacuum Pump Resource Guide
Minimizing maintenance
Adding an automatic controller can reduce pump mainte- nance. Pumps that automatically adjust the motor speed usu- ally run at much less than full speed. The lower speed makes a pump quieter and reduces wear.
Also, the controller itself needs only minimal care. It may require cleaning at some point if you’re pulling wet vapor through it, but it usually won’t require maintenance.
So, adding a controller makes vacuum pumping easier to use and more effective, all without much trouble.
Vacuum Pumps to Replace
Your Water Aspirator
Why it’s time to replace your water aspirator with a vacuum pump
by Erica Tennenhouse
Water aspirators, once a staple in many biology and chemistry labs, are becoming an increasingly uncommon sight. These devices connect to a lab faucet, and as water flows through
a narrowing tube inside the aspirator, its velocity increases, creating a vacuum in the connected sidearm. Their historic popularity stemmed mainly from their low purchase price. But a closer look at the performance, environmental impact, and lifetime cost of a water aspirator may help convince lingering aspirator enthusiasts that it’s time to switch to a vacuum pump.
Performance
Water aspirators are capable of producing a moderate vacuum, in some cases reaching as low as 10 torr. While suitable for use in rotary evaporation or filtration systems using funnels or solid-phase extraction cartridges, water aspirators do not reach the deep level vacuum required for certain applications, such as evaporating high-boiling-point solvents. Another drawback of water aspiration is that the end vacuum depends on the water pressure of the faucet and the water temperature. A water aspirator might produce good
vacuum when used alone but may not be sufficient when used in a lab with other simultaneous users. As well, variable
water temperatures between seasons may mean that naturally warm water in the summer will produce less vacuum than with cooler water in the winter. With an inconsistent vacuum, experiment replication becomes a challenge.
Environment
Water aspirators fall short when it comes to environmental impact. Intensive water use is a major concern with water aspiration, which requires a continuous flow of water from the tap. With moderate daily use of the device wasting an estimated 50,000 gallons of water per year, water aspiration is subject to increasing regulation. Water aspiration often leads to water contamination, as these devices can draw up volatile solvents, which then get carried through the device and down the drain. Combined, there is a significant environmental im- pact, in terms of both wasted water and pollution when using water aspirators.
Cost
A simple aspirator can be purchased for as little as $50. But the real cost lies in the cost of ownership—the copious use of running water and having to dispose of hazardous waste. Ad- ditionally, water aspirators run the risk of causing lab flooding if a sink drain gets blocked during use, which could result in an enormous cost.
The alternative
Vacuum pumps solve many of the problems associated with water aspirators. An environmentally friendly alternative, vacuum pumps completely avoid the issues of water waste and contamination. And by eliminating the water use and treatment costs associated with an aspirator, the initial cost of a vacuum pump potentially can be recovered in a few years.
Vacuum Pump Resource Guide
Vacuum Pump Resource Guide
Where water aspirators fail to provide a deep enough vacuum for certain uses, vacuum pumps deliver. A simple dry lab pump can reach about 1 torr, which is deep enough to handle most lab applications. And an oil pump can achieve a substan- tially deeper vacuum; however, oil pumps also require more
maintenance and can become contaminated. Use of a vacuum pump provides the user with greater control over the vacuum, which leads to improvements in key lab applications; for ex- ample, a vacuum pump reduces bumping during evaporation.
Product Spotlight
Next-Generation LABOPORT® Vacuum Pumps— Unique Design for Lab Life
A new series of three KNF diaphragm pumps expands upon the proven LABOPORT pump innovations of oil-free, non-contaminating, chemically-resistant construction with a modern look and added benefit of speed-controlled DC motors for greater versatility. The new pumps also feature exceptionally small footprints (10 – 20% reduction) and lighter weight (5 – 30% reduction) for improved portability.
A color display indicates pump status at a glance. Smooth rounded surfaces enable easy, thorough cleaning. An integrated gas ballast valve in the two larger models facilitates short process times, even for high-boiling solvents.
Lab Manager 10
These two models are also expandable with optional separator and/or condenser modules. This approach provides a cost-efficient way to expand pump functionality as needs grow.
Maximum flow rates for the new series ranges from 7 – 34 L/min with ultimate vacuum levels from 97.5 – 4.5 torr. Applications include rotary evaporation, degassing, filtration, SPE, fluid aspiration, gel drying, centrifugal concentration, vacuum ovens, and more. (PDXO) tumor
models and patient-derived organoids (PDO) organoid models.
LEARN MORE
Simple Tips to Keep Your Lab Vacuum Pump Running at Its Best
Because vacuum pumps are such a crucial part of many labs, it’s essential to keep this equipment in top shape
by Aimee O’Driscoll and Ajay Manuel, PhD
A vacuum pump is a vital piece of equipment in most labs. There are various types of vacuum pumps, but many are impacted by com- mon issues, such as exposure to solvents or wearing of parts. These problems can lead to an inefficient process and shorten the lifespan of your pump. Here, we provide simple tips to keep your vacuum pump running at its best for as long as possible.
Follow the manufacturer’s instructions for maintenance and use
As vacuum equipment and instruments that depend on vacuum technology can cost tens of thousands if not hundreds of thousands of dollars, proper maintenance and use of vacuum equipment, by following the manufacturer’s recommendations, is recommended by many experts. By taking advantage of the feedback the components provide by logging operating parameters, and service actions to de-
liver optimal performance, reliability, and longevity, a pump’s critical operating parameters can be monitored carefully to provide optimal performance.
By consulting the user’s manual, contacting the manufacturer for additional guidance, reaching out to the sales rep, and reviewing in-
structional videos and online resource, common mistakes such as not properly installing replacement parts and incorrectly reassembling pump components, can be avoided. Manuals will provide advice spe- cific to the type of pump you’re using. For example, oil pumps require warm-up time to achieve the best performance, and oil should be inspected regularly to ensure no solvent has accumulated. Meanwhile, for diaphragm pumps, the membranes must be kept dry to increase their longevity and offer best performance.
The maintenance cycle is also important, and this is dictated by the type of pump and is dependent on the conditions of the application, including temperature, pressure/vacuum, and chemical compatibility.
Protect the pump from solvent vapors
A common issue with several types of pumps is exposure to solvent vapors. This can cause premature wear and seriously damage the pump, so measures should be taken to minimize the chance of vapor exposure and buildup. One way to do this is to ensure ample cooling of the solvent.
Experts suggest that for systems handling solvent vapors, having a suitable cooling source, and applying appropriate vacuum without setting the pressure too low, will help condense vapors before reach- ing the pump. Furthermore, in-line condensers or solvent traps can provide increased surface area for heat exchange to remove thermal energy from vapors, collecting them before they come in contact with the pump.
These steps are even more crucial to avoid exposure when dealing with corrosive solvents. In these cases, an acid neutralizer is recom- mended to be placed in the vacuum line to reduce direct exposure in the pump.
Regular maintenance and checks is advised on any parts attached to a pump, such as tubing, filters, and liquid traps, to avoid any form of liquid or particulate ingress into the head, and to be aware of damage or wear and tear, which may potentially lead to issues in the future.
Vacuum Pump Resource Guide
KNF Neuberger, Inc. is a leading manufacturer of reliable oil free laboratory vacuum pumps,
systems, and controllers; liquid dosing/metering and transfer pumps; and rotary evaporators. All KNF laboratory prod- ucts offer compact design, long service life, and dependable performance. Contact KNF Neuberger today to
discuss your specific laboratory needs.
www.knf.com
Vacuum Pump Resource Guide
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