I like the way you said “it’s simple physics” followed by a completely unsubstantiated and plainly erroneous claim. Although dry ice/acetone or LN2 would be much better and not really expensive anyway - again, with adequate thermal insulation. When placed in a thermally well insulated container, it can easily maintain −20 ☌ for quite a while for a penny. Speaking of hacks, you could make a cold trap using a cooling bath of ice and table salt. But I agree that with a closed-loop system your compounds will be floating in the loop, which is sorta why you never see such systems in real use. The older ones often pulled crappy vacuum, but newer ones would provide something like 15 Torr, which is all you can really expect. And they had little back-stop valves built in to stop water from entering the rest of the apparatus if water flow should suddenly stop (saved me at least once, when a piece from the water mains blocked the pump). Moreover, aspirator pumps I was using were completely made of glass, so there were no vulnerable plastic parts. Well you could always use a drying tube to protect against water vapour. Even liquid nitrogen isn’t that expensive if you can buy it from your local welding store. Nurdrage is great, but he doesn’t always do things the right way, which in this case could be either an aspirator or it could be any vacuum pump that doesn’t upstream water vapour protected by a cold trap cooled by dry ice. The chemistry department drains smelled strongly of ether and chloroform. Some of them pulled a very crappy vacuum. Some solvents attack the plastic of the aspirator but the ones I used at university looked like that hadn’t been replaced in a long time. If it’s not water sensitive then part of your dangerous compound will be dissolved or floating in the water loop or flushed down your drain. If your dangerous compound is water sensitive it’ll be ruined by the water vapour. This is not a good way to work with something dangerous. You get a very wet vacuum and when running them off a tap, if the water pressure drops, or you turn the tap off it sucks back water. Posted in chemistry hacks Tagged aspirator, guide, lab, pump, usage, vacuum Post navigationĪspirators are useful and cheap but it’s not always the right tool for the job. It also seems like a really useful device for other hacking tasks outside of home chemistry. The video is really good and provides a lot of useful information. It can pull enough vacuum to boil water below room temperature. We looked it up and the one he is using costs ten US dollars on fleabay. These devices are cheap because there are no moving parts. is saving water by using a fluid pump and a reservoir to drive his aspirator.Īspirator pumps use the Venturi effect to create a vacuum. School pumps generally use flowing tap water to produce the vacuum. You might remember something similar from high school chemistry. demonstrates the proper usage of a much cheaper option: an aspirator vacuum pump. For the home chemist who’s already having enough trouble just buying the chemicals needed for neat experiments, this is not an option. You just drop three grand on a Teflon diaphragm pump or a liquid nitrogen trap. If you’re a big university or a commercial lab this is no problem. They are primarily designed for atmospheric gasses and tend to melt when exposed to solvents. However, there’s a problem with just going to the local import store and buying the first vacuum pump on the shelf. For example, a potentially dangerous chemical can be boiled and distilled at a much lower temperature than at atmospheric pressures. For the home chemist it is occasionally desirable to pull a vacuum. Puts out a lot of neat videos, mostly about home chemistry.

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