How to Use a Vacuum Pump?

Introduction

Working in a laboratory requires considerable knowledge and skills. It is important to understand how things work to complete the task in an efficient way and to maintain safety as well.

Laboratory workers use various equipment. Among other devices, there is a vacuum pump.

What is a vacuum pump? It is a piece of equipment that draws gas molecules from a sealed chamber to create a partial vacuum. Such pumps are used for:

providing suction for aspiration & filtration;
controlling vapor pressure for solvent evaporation in concentrators, gel dryers, vacuum ovens, desiccators, and rotary evaporators.

There are different devices suitable for different purposes. Some applications require very deep vacuum, for instance, atomic physics, field emission microscopy, X-ray photoelectric spectroscopy, etc. Vacuum pumps are also used for the improvement of the sensitivity of the instrument in such applications as mass spectrometry.

Using a Vacuum Pump in the Laboratory

The process of using a vacuum pump in the lab is easy, you just need to follow a few simple steps.

How Does a Vacuum Pump Work?

It is important to know how your equipment works to use it properly and achieve the results you want.

Vacuum Pump + Bell Jar

Let’s see how a vacuum pump works with a bell jar.

Things you will need:

vacuum pump
glass bell jar
platform
rubber vacuum mat (on top of the platform)

Please note that inside the platform, there is a hole. Whenever you put something inside the bell jar, make sure you don’t cover the hole up. Otherwise, your vacuum pump won’t work properly.

Follow the steps below.

1. Connect the platform to your vacuum pump using a hose.

2. Put the bell jar on top of the platform.

3. Switch on the vacuum pump. The ON/OFF switch is typically located at the back of the pump.

4. Make sure the vacuum pump is working. You can raise the bell jar holding it by the top. The platform should rise with the bell jar if everything goes the right way.

5. Put the platform with the bell jar on the table again and switch off the vacuum pump.

The air is removed and there is less air pressure inside the bell jar. There is heavier air pressure pushing down. As a result, the bell jar is stuck to the platform.

6. Now you can remove the hose to release the vacuum.

Vacuum Pump + Bell Jar + Whipped Cream

Now let’s figure out how a substance will react under vacuum.

For this purpose, to the things we have just used, add a beaker with some whipped cream (or, for example, shaving cream).

1. Take a beaker and put some whipped cream inside of it.

2. Then, put the beaker on the platform and cover it with a bell jar.

3. Switch on your vacuum pump.

4. You will see that your whipped cream is inflating.

5. Remove the valve and your whipped cream will deflate again.

We hope that now you know how a vacuum pump works.

Using a Vacuum Pump for Vacuum Filtration

As we mentioned earlier, a vacuum pump can be used in various applications. Let’s take a closer look at one of them.

Vacuum filtration is used to separate solid in liquid for the mixture. This process is widely used when the solid is the product you are interested in and the liquid is waste. With the help of a vacuum, you can drive the filtration process. Vacuum filtration is effective and fast as well.

Things you will need:

electric vacuum pump (with rubber hosing)
side-arm conical flask
funnel (preferably a Büchner funnel) with a rubber bung
beaker (to contain the mixture)

1. Connect your vacuum pump to a side-arm conical flask with the help of a rubber hose.

2. Get the funnel. If you are going to collect a large amount of solid, a Büchner funnel is the best option.

3. Make sure that the rubber bung on the Büchner funnel fits snugly in the conical flask.

4. Get the properly sized filter paper and put it inside the funnel. Note that the filter paper must cover the holes of the funnel.

5. Pour in the mixture of liquid + insoluble solid. The beaker with the mixture can be rinsed once again.

6. Rinse the collected solid with distilled water.

7. When the product is dry, switch off the vacuum pump.

8. Remove the rubber hose to release the vacuum.

9. Remove the funnel from the conical flask.

10. Place the filter paper with solid on a watch glass and then scrape the solid from the filter paper.

Safety Measures

NB When working in a laboratory and using a vacuum pump and/or other equipment, make sure all safety rules are followed:

Protect your vacuum pump & hose using a trap. This way, you will prevent vapors from being released into the room. People working around as well as other equipment in the laboratory will be protected from potentially hazardous materials.
Prevent implosion, use only vacuum-rated glassware.

When subjected to vacuum, standard glassware may implode. For example, for vacuum filtering applications, consider using heavy-walled flasks. It is better to use PVC-coated glass filtering flasks or Nalgene filtering flasks (they won’t produce flying glass shards in case they fall).

Use suitable personal protective equipment. When using a vacuum pump, various hazardous situations may occur. Always use a face shield, gloves, lab coat or coverall, and other PPE. Keep your face and body covered.

Final Thoughts

Hopefully, now you understand how to use a vacuum pump. You just need to follow a few simple steps. In addition, don’t forget about safety rules.

Lab workers know that using reliable and quality equipment is important for achieving desirable results. Choose from a wide range of best-in-class vacuum pumps on our website. Get the right option for your application!