How to Use Vacuum Filtration?

In the laboratory vacuum filtration experiment, customers often filter some samples with a lot of particles or are very viscous. When these samples are filtered, they often fail to pump. This situation is generally due to the liquid in the liquid. It is caused by the solids completely blocking the microporous filter membrane. In this case, the following methods are generally recommended, how to do vacuum filtration, how to set up vacuum filtration and how to use vacuum filtration.

1. Dilute the sample: In the detection and filtration of suspended solids, it is often the case that the high particle content in the water sample blocks the microporous filter membrane and can not move. You can dilute the sample that needs to be filtered and then filter it.
2. Increase the filtration area: now the common vacuum filter bottle on the market can be placed with a 50mm diameter microporous filter membrane. Replace a set of filters that can place a larger diameter filter membrane, so that the solids in the sample are not so easy to block the filter. membrane.
3. Increase the vacuum degree: replace a vacuum filter pump with a higher vacuum degree. The suction filter pump with a higher vacuum degree has more force during suction and may alleviate the phenomenon of the inability to filter to a certain extent.

Hawach 300ml vacuum filter set
300ml glass solvent filters/ 500ml glass solvent filtration apparatus to suck out the solvent and it will evaporate. The loss of solvent pressure filtration is to squeeze out the solvent. Generally, there will be more solvent residue in the filter cake. It is better to use a centrifuge to separate the material, fully enclosed it, and automatically unload it. Both environmental protection and low labor intensity. If you don’t care whether the loss of solvent and residue is the same as pressure filtration and reduced pressure filtration, both can be used.

How to use vacuum filtration?

1. How to set up vacuum filtration? The filtration apparatus consists of a filter flask, a Buchner funnel (or other filter types), a vacuum pump, and a rubber stopper or adapter to connect them all. Install the instrument and vacuum filtration setup, and check whether the connection between the Buchner funnel and the suction filter bottle is tight and whether the connection port of the suction pump is leaking.

2. Trim the filter paper to be slightly smaller than the Buchner funnel but cover all the holes, add distilled water dropwise to wet the filter paper, and slightly open the exhaust valve to make the filter paper and the funnel tightly connected.

3. Connect the vacuum pump, and connect the vacuum pump to the sidearm of the filter flask using vacuum tubing, making sure that the connection is tight and secure.

4. Start the vacuum pump (Standard Vacuum Filtration Pump, Anti-Corrosion Diaphragm Vacuum Pump), turn it on the vacuum pump, and adjust the pressure to the desired level for the specific application. The vacuum will pull the liquid through the filter paper and leave the solid material behind.

5. Slowly pour the liquid to be filtered into the filter funnel, and pour the solid-liquid mixture, making sure not to overfill it. Start suction filtration. Try to keep the material to be filtered in the center of the Buchner funnel to prevent it from flowing directly through the gap between the funnel and the filter paper without being filtered. The liquid will pass through the filter paper and be drawn into the filter flask.

6. Once the filtration is complete, first remove the suction filter bottle to take over, turn off the vacuum pump and remove the rubber stopper or adapter. Carefully remove the filter paper with the solid material from the funnel and collect the solid material in a container.

7. When taking out solids from the funnel, remove the funnel from the suction filter flask, hold the funnel tube in your left hand, turn it upside down, and “slap” the left hand with your right hand to make the solids fall onto the clean paper or watch glass together with the filter paper. Remove the filter paper and dry the solid. The solution in the suction filter bottle should be poured out from the upper mouth.

8. Clean the filtration apparatus, clean the filter funnel, filter paper, and filter flask thoroughly after use to prevent contamination and maintain its performance.

Overall, it is important to handle the filtration apparatus and the filtered material with care to ensure safe and accurate results. The vacuum filtration technique is widely used in many applications, such as in chemistry, biotechnology, and environmental science.

Precautions
1. When installing the instrument, the inclined surface of the lower end of the funnel tube should face the branch nozzle. But not too close to avoid the filtrate being pumped away.
2. When the filtered solution has strong acidity, strong alkalinity, or strong oxidation, glass fiber should be used instead of filter paper or glass sand funnel should be used instead of the Buchner funnel.
3. It is not suitable to filter the colloidal precipitate or the precipitate with too small particles.
4. In the process of suction filtration, when cracks appear in the solid layer in the funnel, use glass plugs or the like to compress them to block the cracks. If it is not compacted, the suction efficiency will be reduced.
5. When stopping suction filtration, first unscrew the cock on the safety bottle to restore normal pressure, and then close the suction pump.