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HEPA filtration and electrostatic technology
HEPA filtration and electrostatic technology
We all know that in the air filtration industry, there have always been objections to HEPA filter filtration and electrostatic ash filtration and two technical routes. The application of electrostatic ash removal air filtration products has been promoting "no need to replace consumables" as an "advantage" and "product selling point" to customers. So the "no consumables" they often say is really "no consumables"? First master the physical filtration of HEPA filter and electrostatic ash filtration.
1. HEPA high-efficiency filtration technology, good filtration efficiency
HEPA is an internationally recognized and best high-efficiency filter material. The HEPA filter screen is composed of a stack of sub-glass fiber membranes (PP and polypropylene materials are common in purifiers) that continuously stretch back and forth. Placement and support point filter boundary mass. There is a positive correlation between the area between the filtration efficiency of the HEPA efficient particle filter and the filter efficiency. At this stage, the HEPA-efficient particle filters of the HEPA air filtration equipment are all double-layer expansion and contraction, and the total area is increased by ten to dozens of times compared with the expansion, and the filtering efficiency is very good.
Cleaning principle: the principle of particle inertial force and the principle of external diffusion.
HEPA clean technology advantages:
The actual effect of filtering fine particles is more outstanding! The ability to capture particles is strong, the diameter is small, the adsorption volume is large, the cleaning efficiency is high, and it has the ability to absorb water. The cleaning rate for 0.3μm particles is 99.97%. If it is used to filter thick tobacco smoke, the actual effect of filtering can basically be 100%. For particles above 2.5μm, only F8 filter can be used, and the actual filtering effect is above 99%.
HEPA clean technology flaws:
In my country, the dust situation is serious, and the service life of HEPA is likely to be relatively reduced, which means that the HEPA filter must be replaced frequently and the application cost will increase.
2. Electrostatic dust collection technology, no consumables for ash removal
The electrostatic dust collection technology uses the principle of high-voltage electrostatic adsorption to filter the air pollutants in the air. It is also used as a basic cleaning technology and is widely used in household fresh air systems.
Cleaning principle: The effect of high pressure electrostatic field, fine particles are adsorbed on the negative plate or positive plate, and different positive charges are attracted to each other.
Technical advantages of electrostatic dust collection:
A. High-efficiency removal of particulate air pollutants in the air, such as dust, soot, bee pollen, tobacco smell and kitchen exhaust.
B. No consumables, cleaning can be reused many times.
Technical defects of electrostatic dust collection:
A. It is very easy to cause reactive oxygen species, and it only has practical effects on large-particle vapors such as fine particles. The key is to remove ash, and it is basically unrealistic to remove organic chemical environmental pollution caused by building decoration such as formaldehyde, volatile phenol, and TVOC. The effect is equivalent to the middle-efficiency filter.
B. The essence of cleaning also belongs to physical cleaning, and the harmful substances are not dissolved by organic chemistry.
Application suggestion: Note that the electrostatic dust collector should have a cleaning reminder, so it is better to use it.
Do you know the dangers of ozone?
In 2007, the Seattle government department of the United States announced that it would discourage the sale of air purifiers containing reactive oxygen species and electrostatic dust removal equipment. This is because electrostatic ash removal will inevitably cause reactive oxygen species in the whole process of work, and ozone is harmful to the human body. Health has adverse effects!
Internationally, there are established requirements for the concentration of active oxygen in the air. When the concentration of carbon dioxide is lower than 0.05PPM, that is, 0. mg/m3, it is safe, and when the concentration of carbon dioxide in the air per cubic meter is not running, it reaches 0. mg At this time, your throat, nostrils and other human organs will feel irritation. When this concentration value reaches 0.1mg/m3, respiratory diseases will be aggravated, and the eyes will feel irritation.
No consumables", the advantage is the defect
Cleaning frequency is high. Although the air purifier using electrostatic dust removal does not need to replace the filter, the dust collection equipment must be cleaned on time, and the electrostatic dust collection is faster than the saturation of the HEPA filter, and the high filtration efficiency varies with the dust collection on the pole piece. reduce. If it continues to start under heavy haze pollution, the dust collection equipment needs to be cleaned once after 1 to 2 weeks of high toughness application. The difficulty of cleaning is high, and the manholes must be pre-buried. Cleaning the dust collection equipment is not as simple as washing the sheets or brushing the dishes. The dust collection equipment is all grooved, and the fine particles are adhered to it after being carbonized by high pressure, and it is difficult to remove after accumulation. With a secondary cleaner, it is difficult to brush out the inside without a soft bristle brush. Therefore, the specific consumables of the electrostatic dust collection method are low-cost and the maintenance labor is large and complicated, and the general customer consumes a large amount of electricity. Electrostatic ash removal must be additionally plugged in to cause high-voltage static electricity. Generally speaking, it is 1-2 times the power consumption of HEPA filter. Moreover, because of the working principle, you can hear a crackling sound, much like an electric mosquito killer. Mosquitoes, kind of scary, but not that loud.
In fact, in terms of the dust holding capacity of the HEPA filter, it can be guaranteed to be replaced once a quarter or half a year. In general, the electrostatic dust collectors promoted and planned on "Keppu Raw Materials" do not need to change the filter screen, and the advantages of saving consumables in the circulation system are not obvious. On the contrary, it is a defect because it takes hard work to remove it frequently.
The other real defect of electrostatic dust collection seems to be in the removal of dust, specifically in the removal of ozone
"No consumables" is a partial generalization, and the cost of specific consumables increases. If the dust collecting equipment is not cleaned after it is saturated, the surface air pollutants will be easily removed, and the carbonized fine particles will be fluttered with the wind and sprayed out again, which will cause secondary pollution (the walls around the vents will turn black). To deal with this problem, it is also necessary to modify a medium-efficiency filter screen in the final layer to block it. Therefore, we can see here that electrostatic ash removal cannot replace everything. In order to better ensure the actual effect of filtration, the front-end development of electrostatic should add a coarse filter screen, and the back-end development should add activated carbon and vertical filters. The filter screen, absorbing carbon powder, and absorbing active oxygen, to put it bluntly, "no consumables" is actually a partial generalization, and the cost of the specific consumables that must be replaced is comprehensively high.
Because the electrostatic type has a fixed dust collector and touches the cost of the construction cost, the cost of making small and medium models cannot go down. And its characteristics of a lot of wind cannot be fully utilized in small indoor spaces. More importantly, in a small indoor space, the carbon dioxide concentration is too high to cause harm to the body.
In general, in a small indoor space, the carbon dioxide concentration is too high to cause harm to the body! Therefore, when purchasing household fresh air system products, it is recommended that many customers choose the household fresh air system with HEPA filter!
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