There are so many brands of water purifiers, and a variety of functional parameters, such as RO reverse osmosis, CTO carbon fiber filtration, and GAC carbon fiber, make people dizzy. In fact, this is the business deliberately raising the recognition threshold, giving you a high-end feeling that you can't understand, and then inducing you to buy.
In fact, these parameters are not so complicated. Today, let's look at the characteristics of mainstream products and understand the principle of water purifier.
Filter barrel parameters
PP cotton, filter large particles of impurities, such as sand, rust, etc
High-precision PP cotton, filtering small particles of impurities
Carbon fiber can absorb residual chlorine, organic matter, odor, impurities and heavy metals
Activated carbon particles can improve the taste, remove the odor, and make it sweet and delicious
(No matter what the English abbreviations of CTO, GAC and so on, the fancy information will be filtered out, and it will never change. The key of CTO activated carbon is activated carbon, not CTO)
RO reverse osmosis, the strong pressure forces water molecules to pass through the RO osmosis membrane. Except for hydrogen and oxygen molecules, other fine impurities cannot pass through.
MF filter element and UF filter element with similar functions are essentially used to filter bacteria, viruses and antibiotics
working principle
The essence of the working principle of the water purifier is filtration.
Large and small filters, layer by layer, keep unwanted impurities and odors out of the door, and get the drinking water we want. In this process, manufacturers will use these PP cotton, activated carbon, RO reverse osmosis membrane, etc.
Some manufacturers line up with multiple filter buckets to filter, first PP cotton, then activated carbon, and finally RO reverse osmosis membrane. How to make it comfortable? Some people are not sure how to use PP face and activated carbon many times, and then pinch back and forth. Because RO is too expensive, it usually only appears once.
This is the RO membrane, many layers
Some manufacturers have combined the above filter screen and used PPcotton, activated carbon and other materials together in one bucket, N in one, with the function of multiple buckets. The advantage is to reduce the number of filter buckets and save the volume.
So we can see that some products have 4-level filtration and some have 2-level filtration. It should be emphasized here that level 2 is not necessarily worse than level 4. There may be three-in-one and four-in-one filter screens in this level 2 filter. If you take it apart, this level 2 filter actually has five or six layers, which is more than that level 4 filter.
RO membrane reverse osmosis, which should be emphasized. The pore size of RO membrane is one millionth (0.0001 μ m) of the hair. The volume of bacteria and viruses is far more than this pore size, almost more than 5000 times. Only water molecules and some mineral ions can pass through, so it can isolate viruses and bacteria. Therefore, RO membrane is also called "artificial kidney" in vitro.
Because the pore size is too small, the water molecules will not easily pass through. A lot of pressure needs to be applied to turn the water pressure into small molecules through the RO membrane. The greater the pressure, the faster the penetration, and the more pure water will be produced.
[Parameters of water purifier]
Penetration specification: 400G, 600G, or 400 gallons, which means that such water purifier can produce 400 gallons of clean water a day. The higher the value, the higher the water yield. At present, the largest one is 1000G, and the 352 brand is doing it.
Terminal flow: the speed of the water flowing out of the faucet, in L/Min, which indicates how many liters are flowing out per minute. The greater the pressure, the faster the speed, and the shorter the time for receiving a cup of water.
Recovery rate/waste water ratio: under strong pressure, if there is water passing through the membrane, there will be water flowing into the waste water pipeline with waste and bacteria. The less waste water produced, the stronger the water production capacity of the product. Xiaomi's ratio is 1:1, which is not high. If you get a cup of clean water, a cup of waste water will flow out of the sewer.
The pressure of the water storage bucket can not be too high when there is a water storage bucket, and it can be pressed slowly and stored slowly. The advantages of this bucket design are cheap, but the disadvantages are that water accumulation, easy to breed bacteria and be contaminated, that is, "not fresh". Generally, the RO specification is 50G; Barrel-free design requires a lot of pressure, which has higher requirements for the pressure manufacturing of the machine and the RO membrane. Fresh water will be produced immediately when needed.
The number of filtering stages is not repeated. The quantity is the representation, which depends on the essence.
The rated net water volume is the key point. Take notes, take notes, take notes! The concept that a filter can be used for two years and three years is very false. The manufacturer doesn't know how to use water at ordinary times, and uses it every day. The filter may expire within three months; Once a half year, maybe you can use it for 10 years.
Therefore, the service life of the filter screen cannot be measured by the service life, but by the rated net water volume. 5000L represents that this filter can produce 5000L of clean water, which can be replaced after use, regardless of how many years I use it. The larger the number, the better.