The average person rarely stops to think about filtration technology, but it actually has a huge impact on our daily lives. Most water treatment processes depend on it, but it also plays a role in a huge number of industries and even in cooking. There are a lot of different filters out there that are designed for specific purposes, but they all run on the same basic methods. That makes it fairly easy to understand how they work.
1- Size Matters
A filter is essentially a piece of material with a bunch of tiny holes passing through it. Many of those holes with be microscopic, and they can vary in their precise size. The substance that is being filtered passes through the holes in the filter, but all of the contaminants in it get stuck.
That means that the size of the holes is the factor that determines the effectiveness of the filter. The holes need to be big enough to allow the main substance to pass through them, but they also need to be small enough to catch all of the contaminants. That means that filters sometimes need to be specialized for specific purposes to make sure that they do not let anything through that should have been caught.
2- It Takes Time
Fluids can only flow at a limited speed. While it is possible to make the process go faster by pumping the fluid through a filter rather than letting it flow naturally, the substance will still need to take the time to get through the filter.
The speed can even vary depending on the quality of the filter, especially for the ones that people use at home. In those cases, replacing an old filter can make the process go much faster. The type of filter and the substance that is going through it are also important variables for determining how quickly the filtration process will occur. Most people can’t do much to change how fast their filters work, so it pays to be patient and plan ahead when using them.
3- The Conditions Matter
Many filtration techniques require that the substance to be filtered is at a specific temperature, or even in a vacuum. That is because the behavior of chemicals can change based on the conditions that they are experiencing at the time. For example, the filtration apparatus can be heated before it filters a hot substance to make sure that crystals do not form while the filtration takes place.
4- Filter Types
Filters can be grouped into two broad categories, the surface filters and the depth filters. Both have their place, but they fill different roles.
Surface filters rely on a solid, porous material. Some of them may have a layer of filter paper on top, but that is not always necessary. These filters are useful because they make it possible to trap the contaminants that get filtered out of the fluid. That is valuable in laboratory environments, or in any industry where the contaminants are valuable.
A depth filter is more like a layer of gravel. It has a lot of little pieces that trap solids as a fluid passes through them. That makes it very hard to collect the solids that have been filtered out, but it works much better when there is a risk of clogging.
5- Advantages and Disadvantages
Filtration is not the only way to get solids out of a fluid, although it is one of the most common. People like to use it because it is fairly cheap, easy to do, and relatively efficient. The big downside to relying on filtration is time. It is much slower than most of the other methods, and that can make it less useful in some industrial settings.
That generally is not a problem for the average person, which is why water filters are so popular in the home. That is why many of the alternatives, such as centrifuges, are likely to stay restricted to laboratory or industrial use for the foreseeable future. Filters are simply more practical for the vast majority of roles, and technological changes are unlikely to change that fact for domestic purposes any time soon.