CN2778371Y - Plasma and light catalyzing combined air purifier device - Google Patents

Abstract

The utility model discloses an air purification device. The method utilizes the synergistic effect of plasma purification technology and photocatalytic purification technology to eliminate toxic and harmful gases and achieve the purpose of purifying air. The device is mainly composed of a filter screen (1), a low-temperature plasma generator group (2), an electrostatic filter screen group (3), and a photocatalytic unit composed of photocatalytic nets (4) and ultraviolet lamps (5) arranged at intervals And blower fan (6) is formed. The utility model can effectively purify toxic and harmful gases produced in municipal sewage treatment facilities, industrial production, commercial places, entertainment places, hotels, office buildings and living rooms, and has the characteristics of broad spectrum and high efficiency.

Description

A plasma and photocatalytic composite air purification device

technical field

The utility model belongs to the technical field of environmental protection, in particular to an air purification device. More specifically, it relates to a device that converts volatile organic compounds and other harmful gases generated in municipal sewage treatment facilities, industrial production, commercial and entertainment venues, hotels, office buildings and living rooms into harmless substances and then discharges them.

technical background

With the improvement of people's requirements for environmental quality, the treatment of toxic and harmful gaseous pollutants (such as H ₂ S, SO ₂ , NH ₃ , NO _x , VOCs, etc.) discharged from municipal facilities and industrial production is the key to improving environmental quality. The key point is that these pollutants have no recovery value, but also endanger the ecological environment and people's health. Therefore, how to purify these toxic and harmful gases has become an urgent problem in the field of environmental protection.

In order to improve air quality, people have done a lot of work, such as using activated carbon adsorption purification method, chemical reaction method, catalytic purification method, biological purification method, etc., but these methods have certain limitations. For example, although the purification speed of the activated carbon adsorption purification method is fast and has the effect of adsorption and purification on many pollutants, there is a saturated adsorption capacity for the adsorption of pollutants by activated carbon; when the adsorption is closer to saturation, the adsorption speed is slower. When the adsorption reaches When the adsorption capacity is saturated, the purification effect will be lost. At this time, the activated carbon must be regenerated to partially restore its adsorption performance; from the perspective of system environmental pollution, the process of adsorption, purification and regeneration of activated carbon is the process of transferring pollution, so it can be It is not considered a thorough method of air purification. The chemical reaction method uses various chemical substances to react with pollutants to achieve the purpose of air purification, such as using ferrous sulfate or hydrated ferrous oxide to remove hydrogen sulfide in the air, and using iodic acid to oxidize aldehydes, etc. These can be combined with Substances with which pollutants chemically react (also known as deodorizers or deodorizers) are continuously consumed during the purification process, and a deodorizer is only effective against a limited class of pollutants. The catalytic purification method usually uses catalysts such as noble metals to catalyze at a certain temperature to oxidize or reduce pollutants to non-toxic substances, and usually requires an additional heating device. The biological purification method uses microorganisms to purify the air. Due to the wide variety of pollutants in the air, it brings difficulties to the cultivation of bacteria.

Low-temperature plasma technology and photocatalytic technology are new advanced air purification technologies that have emerged in recent years. Low-temperature plasma technology uses active groups generated by corona discharge at normal temperature and pressure to decompose harmful components in the air to purify the air (such as CN1515840A), while photocatalysis technology uses ultraviolet light or visible light to excite titanium oxide semiconductor ultrafine particles to produce Holes and electrons, these holes and electrons migrate to the particle surface, interact with the adsorbed water or hydroxyl groups on the surface of the photocatalyst to generate active groups (such as hydroxyl radicals OH and HO ₂ ^-etc .) to decompose pollutants to achieve air Purification (such as CN1456357A, CN1463754A). Both of these two technologies have the advantages of mild reaction conditions, thorough reaction, and the ability to treat almost all pollutants in the air. Studies have shown that there is a certain synergy between low-temperature plasma technology and photocatalytic technology, so how to combine the two through some technical means to further improve the purification efficiency has become a research hotspot.

Mainly be divided into two classes in the existing plasma-photocatalysis composite technology: (1) photocatalyst is directly attached on the plasma generating device, as in the tube wall coating photocatalyst film of plasma generating tube (CN 2660374, EP1249265), this composite method has the disadvantages of low photocatalyst surface area and increased difficulty in the preparation of plasmonic devices. (2) The electromagnetic wave generated by the plasma is used as the excitation light source of the photocatalyst (JP 2000325447). The biggest problem in this composite method is that the intensity of the light generated by the plasma that can be used to excite the photocatalyst is weak, which is not enough to trigger a large number of photocatalysts. Photocatalytic degradation reaction.

Contents of the invention

The purpose of this utility model is to provide a device for air purification, more specifically to make full use of the respective purification effects of plasma technology and photocatalysis technology, while taking into account the synergy between them, to provide a device suitable for most gaseous pollution It is an air purification device for objects to effectively control toxic and harmful gases generated in municipal facilities, industrial production, business and entertainment venues, hotels, office buildings and living rooms.

The air purification device provided by the utility model is composed of a filter screen 1, a low-temperature plasma generator group 2, an electrostatic filter screen group 3, a photocatalytic unit composed of a photocatalytic net 4 and an ultraviolet lamp 5 arranged at intervals, and a fan 6. ; Its structure is shown in Figure 1. Among them, the filter screen 1 is located at the air inlet, the low-temperature plasma generator group 2 is placed behind the filter screen 1, and the electrostatic net group 3 is located between the low-temperature plasma generator group 2 and the photocatalytic net 4 and the ultraviolet lamp 5 arranged at intervals. Between the photocatalytic units, the fan 6 is located at the outlet of the device.

In this device, there can generally be 3-10 plasma generators in the low-temperature plasma generator group 2, which are arranged in a spatially dislocated manner, such as arranged in the shape of "product", so that the plasma concentration distribution in the device can be compared. uniform. The above-mentioned low-temperature plasma generator generally adopts a pulsed corona discharge with a base voltage of 4-15kv and a high voltage of 30-50kv.

In this device, the electrostatic net group 3 generally consists of 3-5 stainless steels arranged in parallel, the meshes are 40-120 mesh, and the distance between two nets is 10-40cm.

In this device, the photocatalytic net 4 is a multi-layer structure composed of polyester foam net, activated carbon particles, and nano-titanium oxide photocatalyst. Among them, the particle size of nano-titanium oxide is 20-100 nanometers, the porosity of the polyester foam net is 10-40pis, and the activated carbon is granular carbon, specifically high-iodine value coconut shell carbon or fruit shell carbon with a particle size of 60-400 mesh . For its preparation method, please refer to the CN116211 patent. The specific steps are: firstly, the granular activated carbon is bonded on the polyester foam net, and then the nano-titanium oxide photocatalyst is loaded by spraying and other processes. The power of the ultraviolet lamp 5 is 20-40w; the photocatalytic net 4 and the ultraviolet lamp 5 are arranged at intervals. Generally, the photocatalytic unit is composed of 2-5 groups of photocatalytic nets 4 and ultraviolet lamps 5 .

In this device, the air volume of the fan 6 is generally 200-8000m ³ /h.

Utilize above-mentioned air purification device to purify the air step as follows:

(1) By means of the fan 6, the air to be purified is passed through the filter screen 1 to remove particulate matter therein;

(2) The filtered air passes through the low-temperature plasma generator group 2, and the active groups (OH, HO ₂ ^- , O ^- ) and ozone generated by the plasma generator are used to eliminate toxic and harmful substances in the air;

(3) The air passing through the plasma generator passes through an electrostatic filter group 3, on the one hand filters the charged dust in the plasma unit, and simultaneously annihilates the charged substances produced by the plasma generator, especially the positively charged holes. The negative ions that act to eliminate its negative impact on the photocatalytic unit in the next step;

(4) The air passing through the electrostatic filter screen passes through the photocatalytic unit composed of the photocatalytic net 4 loaded with nano-titanium oxide and the ultraviolet lamp 5 arranged at intervals, and utilizes the photocatalytic action of titanium oxide to further purify pollutants in the air;

(5) Utilize fan 6 to discharge the purified air.

The utility model combines the plasma technology and the photocatalysis technology together, and by rationally arranging the arrangement of the plasma generation unit and the photocatalysis unit, it not only makes full use of the respective purification effects of the two, but also takes into account the synergy between the two . Compared with the prior art, the utility model has the following advantages and beneficial effects:

(1) There is a certain synergy between the low-temperature plasma purification technology and the photocatalytic purification technology, and the plasma can promote the photocatalytic reaction; The respective purification effects of the two also take into account the synergy between the two, and the purification efficiency is higher;

(2) The ultraviolet light in the plasma can excite the photocatalyst, and substances such as ozone in the plasma can promote the photocatalytic reaction, but the negative ions produced by it will combine with the reactive holes on the surface of the photocatalyst, thereby inhibiting the photocatalysis Function; the utility model adjusts the distance between the plasma unit and the photocatalytic unit, and places a filter material between the two, so as to fully drown out the negative ions generated by the plasma unit and eliminate its negative impact on the photocatalytic unit;

(3) The method and device have a broad spectrum, and have a good purification effect on almost common toxic and harmful gases, so that they can meet the emission standards.

Description of drawings

Fig. 1 is a device schematic diagram of the air purification method provided by the utility model.

Numbers in the figure: 1 is a filter screen, 2 is a low-temperature plasma generator group, 3 is an electrostatic net group, 4 is a photocatalytic net, 5 is an ultraviolet lamp, and 6 is a fan.

Detailed ways

Below in conjunction with accompanying drawing and embodiment further illustrate the utility model.

The air purification method provided by the utility model makes full use of the respective purification effects of the low-temperature plasma technology and the photocatalytic technology, and takes into account the synergistic effect between the two to degrade sewage treatment municipal facilities, industrial production, commercial entertainment venues, hotels, office buildings and The poisonous and harmful gases produced in the living room and other places, in order to achieve the purpose of purifying the air, the steps are as follows:

(1) By means of the fan 6, the air to be purified is passed through the filter screen 1 to remove coarse particles therein;

(2) The filtered air passes through the low-temperature plasma generator 2, and the active groups (OH, HO ₂ ^- , O ^- ) and ozone generated by the plasma generator are used to decompose the toxic and harmful substances in the air;

(3) The air passing through the plasma generator passes through a set of stainless steel mesh 3 to drown out the positive ions produced by the plasma generator to eliminate its negative impact on the photocatalytic unit in the next step;

(4) The air passing through the stainless steel mesh passes through the photocatalytic unit formed by the photocatalytic mesh 4 loaded with nano-titanium oxide and the ultraviolet lamp 5 arranged at intervals, and further purifies the air by utilizing the photocatalytic action of titanium oxide;

(5) Utilize the fan 6 to discharge the purified air.

The above-mentioned low-temperature plasma generator 2 adopts a pulsed corona discharge with a base pressure of 4kV-15kV and a high voltage of 30kV-50kV; there are several groups of low-temperature plasma generators. In order to make the plasma concentration distribution in the purification device more uniform, the plasma The volume generator groups are arranged in the shape of "pin" in space.

Above-mentioned stainless steel mesh 3 is 40～120 meshes, in order to make the positive ion that plasma generator produces fully submerge, stainless steel mesh can be installed 3～5 groups, between 10～40cm between two groups.

The above-mentioned photocatalytic net 4 is prepared according to the method described in patent CN162211. The net is a multi-layer structure composed of polyester foam, activated carbon particles and nano-titanium oxide. The particle size of nano-titanium oxide is 20-100 nanometers.

Each of the above-mentioned ultraviolet lamp tubes 5 has a power of 20-40W, and a group of ultraviolet lamp tubes is placed between each two groups of catalytic nets.

The air volume of the fan 6 is 200-8000m ³ /h.

Example

This device is used in a pumping station of a sewage treatment plant, with an air volume of 3000m ³ /h. The low-temperature plasma generator group 2 is composed of 4 generators, the stainless steel mesh group is composed of 3 meshes (30cm apart), 2 groups of photocatalytic mesh, ultraviolet 1 group of lamps, 2 lights in total, the hydrogen sulfide inlet concentration is 0.21mg/m ³ , and the outlet concentration is 0.03mg/m ³ , reaching the national first-class emission standard, and the degradation rate is 81%.

Claims (5)

1, a kind of air cleaning unit is characterized in that by screen pack (1) one low-temperature plasma generator group (2), a static filter screen group (3), is spaced photocatalysis unit and the blower fan (6) formed by photocatalysis net (4) and uviol lamp (5) and forms; Wherein, screen pack (1) is positioned at the air intlet place, low-temperature plasma generator group (2) places screen pack (1) afterwards, static net group (3) is positioned at low-temperature plasma generator group (2) and is spaced between the photocatalysis unit of forming by photocatalysis net (4) and uviol lamp (5), and blower fan (6) is positioned at the exit of device.

2, air cleaning unit according to claim 1 is characterized in that the low-temperature plasma generator in the described low-temperature plasma generator group 2 has 3-10, spatially becomes dislocation to arrange.

3, air cleaning unit according to claim 1 is characterized in that described static filter screen group (3) is made up of the stainless (steel) wire that 3-5 is arranged in parallel, and mesh is the 40-120 order, and the distance between two stainless (steel) wires is 10-40cm.

4, air cleaning unit according to claim 1 is characterized in that photocatalysis net (4) is organized by 2-5 in described photocatalysis unit and uviol lamp (5) is formed.

5, air cleaning unit according to claim 1, it is characterized in that photocatalysis net (4) by the polyester form net, on foam web bonding activated carbon granule, the nano titanium dioxide photocatalyst of load is formed; The porosity 10-40pis of foam web, active carbon be particle diameter at 60-400 purpose high iodine number coconut husk charcoal or fruit shell carbon, the particle diameter of nano-titanium oxide is 20～100 nanometers.

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