RU104460U1 - PHOTOCATALYTIC FILTER AIR CLEANER - Google Patents

Abstract

 1. An air purifier with a photocatalytic filter, comprising a dust filter, an aerosol charging device, a fine filter, characterized in that the photocatalytic filter includes external and internal side shells, upper and lower end caps, a photocatalytic element in the form of a filling that fills the entire space inside the shells , and ultraviolet lamps with an ultraviolet range of "A" immersed in the inner side shell, as well as a superoxide decomposition unit and a fan. ! 2. The air purifier according to claim 1, characterized in that the outer and inner side shells of the photocatalytic filter are made in the form of enclosing metal grids with cells that prevent leakage of backfill. ! 3. The air purifier according to claim 1, characterized in that the upper and lower end caps of the photocatalytic filter are made deaf to ensure the passage of the cleaned air only through the outer and inner side shells. ! 4. The air purifier according to claim 1, characterized in that the filling is made of fragments of arbitrary shape with a size of 10-50 mm, sintered from glass balls with a size of 0.8-1.5 mm ! 5. An air purifier according to claim 4, characterized in that the surface of the glass beads is coated with anatase modification powder of nanosized TiO2 particles.

Description

The utility model relates to devices designed for highly efficient cleaning of indoor air from dust, all types of aerosols, toxic molecular organic compounds, bacteria, viruses, spores, allergens and other similar microorganisms or agents, namely, an air purifier with a photocatalytic filter.

The most effective way to remove molecular organic and biological air pollutants is currently recognized technology based on the use of photocatalysis. The essence of the photocatalytic method is the oxidation of toxic organic substances, viruses and bacteria on the surface of the photocatalyst under the influence of ultraviolet radiation, while pollutants do not accumulate, but are mineralized to harmless components.

The main applications of air purifiers with a photocatalytic filter:

1. Cleaning and disinfection of air in the premises of residential buildings and office buildings.

2. Cleaning and disinfection of air in the premises of medical institutions, including rooms with a standardized class of microbiological cleanliness (operating rooms, dressing rooms, intensive care units, delivery rooms, etc.).

3. Cleaning and disinfection of air in the premises of the production of medical devices, special civil defense structures.

4. Air purification and disinfection in the premises of shops, dairy children's kitchens, school canteens, cafes, restaurants and bars.

5. Cleaning and disinfection of air in the premises of the storage facilities of museum and library collections.

6. Cleaning and disinfection of air in rooms requiring the organization of local smoking areas.

Known photocatalytic element (patent of Russian Federation No. 2151632 C1, CL. B01D 53/86. Publ. 06/27/2000) in the form of a tube or plate of a given size from five layers of sintered glass balls, on the surface of which is coated a layer of anatase-modified titanium dioxide powder with specific surface area of 100-150 sq.m. Its disadvantage is a sufficiently high resistance to air blowing, which requires sufficiently powerful ventilation devices to operate it as part of the purifiers, therefore such a photocatalytic element can be effectively used in air purifiers only with partial air blowing through the element, and the main stream of cleaned air should flow around it surface. This option is implemented in convective photocatalytic air purifiers.

A known group of fanless (convective) air purifiers with a photocatalytic porous element that acts as a filter for molecular organic pollutants, bacteria, viruses, allergens, etc., for example, US patent No. 20080131311 A1, CL. A61L 9/00, publ. 06/05/2008. Such cleaners are effective for rooms intended for people to rest at night (living quarters, hotels, hospitals, rest houses, sanatoriums, etc.). A common disadvantage of such devices is the very poor efficiency in cleaning air containing suspended liquid droplets, aerosols, odors, tobacco products, etc. in rooms of dining rooms, cafes, restaurants and bars, especially in rooms requiring the organization of local smoking areas.

Known multi-photocatalytic filter (US Pat. US No. US 2007/0251812 A1, CL. 204 / 157.15, publ. 11.01.2007), having a enclosure, inside which longitudinally-transversely placed ultraviolet lamps in quartz covers, and the entire space between the housing and lamps filled with tubular granular bodies mainly of borosilicate glass, coated with a layer of photocatalyst.

The disadvantage of this device is the very poor efficiency in cleaning air containing suspended liquid droplets, aerosols, smells, tobacco products, etc., in the premises of canteens, cafes, restaurants and bars, especially in rooms requiring the organization of local smoking places. Therefore, such photocatalytic filters to create air purifiers require additional equipment with specific capture filters or the presence of pressure ventilation duct air purification systems having a sufficiently high pressure of the cleaned air to overcome the resistance of granular filling.

Known air purifier with photocatalytic filter (patent of the Russian Federation No. 2262455 C1, CL. B60H 3/06, publ. 10/20/2005). In the purifier housing are located: a fan, a filter for trapping solid particles, a heat exchanger, a source of ultraviolet radiation from two lamps and a photocatalytic filter.

The photocatalytic filter in this device is made in the form of a bag composed of separate thin-walled plates made of porous plastic, having on their surface two-sided longitudinal protrusions located at a distance from each other with the possibility of mutual contact with their vertices in adjacent plate plates with the aim of forming flat-slot channels for passage purified air with the possibility of artificial turbulization of the flow. The surface of the plates in the bag is coated with active photocatalytic titanium dioxide powder, which, when exposed to ultraviolet radiation from lamps, decomposes and neutralizes harmful gaseous impurities (carbon monoxide, saturated and aromatic hydrocarbons, chlorine compounds, phenol, aldehydes, alcohols, ketones) when exposed to ultraviolet light from lamps turning them into harmless substances.

The disadvantages of this photocatalytic filter are:

1. Low efficiency in the oxidation and disinfection of air due to the small depth of penetration of ultraviolet rays into plane-slot channels with a sufficiently large curvature.

2. Isolation of products of incomplete oxidation of the material of plastic plates due to the photocatalytic effect on plastic, and, as a result, destruction and corresponding resource limitation of their continuous operation.

3. Insufficient adhesion of the active photocatalytic powders to plastics, as a result of which the catalyst is carried away from the surface of the plates of the photocatalytic filter by the cleaned air stream, which also reduces its service life.

Known air purifier with a photocatalytic filter (patent of the Russian Federation No. 2259850 C1, CL. A61L, publ. 09/10/2005), in which air purification includes the following components:

1. The fan.

2. Filter coarse air from large contaminants.

3. The filter of thin air purification from small pollution.

4. Filters absorbers of various odors.

5. Ozone-free ultraviolet irradiator to remove microorganisms from the air.

6. Photocatalytic filter for the oxidation of gaseous chemical pollutants contained in the cleaned air.

To increase the oxidation state of molecular pollutants in this device, first, by means of mechanical filtration, they purify the air from large and small particles and various odors, after which part of the purified air is taken out of the device into the room, and the remaining part of the air is irradiated with an ozone-free ultraviolet bactericidal lamp to suppress microorganisms and cleaned of molecular pollutants by oxidation in a photocatalytic filter.

The photocatalytic filter in this device is a quartz tube with a layer of photocatalytically active titanium dioxide deposited on their inner surface, irradiated with an ultraviolet lamp in the long wavelength range of the ultraviolet. The disadvantage of such a photocatalytic filter is the low oxidation rate of molecular pollutants, due to the underdeveloped contact surface of a flat unfiltered layer of the photocatalyst on the surface of quartz tubes with a stream of purified air and, as a result, the overall low efficiency of air purification from molecular chemical pollutants, provided that part air flow is generally discharged from the purifier, bypassing the photocatalytic filter.

Known air purifier with a photocatalytic filter (US patent No. 2008/0112844 A1, CL. A61L 9/20, publ. 15.05.2008), designed for duct ventilation systems. This device has a photocatalytic filter, a panel for connecting to the ventilation duct and a control unit. The photocatalytic filter is made in the form of flat mesh panels with a layer of photocatalytic titanium dioxide deposited on them. Photocatalytic lamps with a wide range of ultraviolet radiation, mainly bactericidal, are installed next to the panels. The main disadvantage of this photocatalytic filter is the low efficiency of the process of oxidation of organic pollutants, due to the disproportionate amount of air flow through the photocatalytic filter, the volume of which from the fan does not agree with the maximum rate of the photocatalytic process of oxidation of molecular pollutants, which is determined by the power of the used UV lamps. In this case, the so-called "hardening" of intermediate products of oxidation reactions by free air flows is possible.

Closest to the set of essential features of this utility model is an air purifier with a photocatalytic filter (US Pat. No. 2352382 C1, Cl. A61L 9/20, publ. 04/20/2009). In figure 1. a diagram of an air purifier with a photocatalytic filter according to the patent of the Russian Federation No. 2352382 C1, Cl. A61L 9/20, publ. 04/20/2009 (prototype).

The composition of the known air purifier includes: 1 - dust filter; 2 - aerosol charging device; 3 - fine filter; 4 - photocatalytic filter; 5 - ultraviolet lamps; 6 - block decomposition of superoxides; 7 - power supply and control unit; 8 - fan; 9 - case.

All these elements of the air purifier are mounted in a metal casing, allowing the air purifier to move over the entire area of the cleaned room. This air purifier uses a comprehensive air purification scheme based on a combination of electrostatic, sorption, chemisorption, catalytic and photocatalytic methods.

In this air purifier, a cylindrical photocatalytic filter is made on the basis of a coarse-porous fibrous lavsan with a fiber packing density not exceeding 5%. When applying the catalyst to the filter surface in an ultrasonic bath, a deionized aqueous suspension of titanium dioxide (powder with a particle size from 0.005 to 0.1 μm) with a pH value of 5.5–8.0 was used. The catalyst was activated by boiling in a dilute aqueous solution of sulfuric acid (0.1-10% H ₂ SO ₄ ) or in an autoclave at elevated temperature and pressure in an alkaline medium. A 36 W soft lamp (Phillips PL-L 36W, 400 mm long) was used as a source of ultraviolet radiation. The power of ultraviolet radiation with a wavelength of 0.3 to 0.46 μm was about 9 watts. Such a photocatalytic filter showed good results when purifying air from acetone vapors with a concentration of about 10 ^-4 -10 ^-3 % by volume. The disadvantages of this photocatalytic filter are:

1. The low efficiency of the process of oxidation of organic pollutants, due to the disproportionate amount of air flow through the photocatalytic filter, the volume of which from the fan is not consistent with the maximum speed of the photocatalytic process of oxidation of molecular pollutants, which is determined by the power of the used UV lamps. In this case, the so-called "hardening" of intermediate products of oxidation reactions by free air flows is possible.

2. Low service life, since the synthetic fiber (lavsan) from which the filter is made, during operation of the air purifier, is eroded by the photocatalytic oxidation of synthetics, which leads not only to the gradual destruction of the filter and the limitation of its service life, but also to pollution of the cleaned air products of incomplete oxidation of lavsan.

The objective of the utility model is to develop a new purifier with increased efficiency for air disinfection and its purification from molecular chemical and biological pollutants.

The problem is solved by the proposed air purifier with a photocatalytic filter containing a dust filter, an aerosol charging device, a fine filter, a superoxide decomposition unit and a fan, in which the photocatalytic filter includes external and internal side shells, upper and lower end caps, a photocatalytic element in the form of filling that fills the entire space inside the shells, and ultraviolet lamps with a range of ultraviolet "A", immersed in the inner side shell. The outer and inner side shells of the photocatalytic filter are made in the form of metal enclosing grids with cells that prevent leakage of backfill. The upper and lower end caps of the photocatalytic filter are made blind to ensure the passage of cleaned air only through the outer and inner side shells. The filling is made of fragments of arbitrary shape with a size of 10-50 mm, sintered from glass balls with a size of 0.8-1.5 mm. The surface of the glass beads is coated with anatase-modified TiO ₂ powder with nanosized particles in the specific surface area range of 100-400 m ² .

The essence of the claimed utility model is as follows.

In figure 3. presents a diagram of a utility model of an air purifier with a photocatalytic filter for this application:

1 - dust filter; 2 - aerosol charging device; 3 - fine filter; 4 - photocatalytic filter; 5 - ultraviolet lamps; 6 - block decomposition of superoxides; 7 - power supply and control unit; 8 - fan; 9 - cleaner body; 10 - the outer side mesh shell of the photocatalytic filter; 11 - photocatalytic element in the form of a bed of fragments of arbitrary shape, sintered from glass balls coated with TiO ₂ ; 12 - inner lateral mesh sheath; 13 - upper end cap; 14 - lower end cap.

The implementation of the claimed utility model is characterized by the following examples.

Example 1

An air purifier with a photocatalytic filter (FIG. 1) is manufactured according to the patent of the Russian Federation No. 2352382 C1, Cl. A61L 9/20, publ. 04/20/2009 (prototype).

The prototype air purifier includes a dust filter (1), an aerosol charging device (2), a fine filter (3), a photocatalytic filter (4), ultraviolet lamps (5), a superoxide decomposition unit (6), a power and control unit (7 ), fan (8) and housing (9). The cylindrical photocatalytic filter (4) is made of fibrous lavsan with a fiber packing density not exceeding 5%. A powder of photocatalytic titanium dioxide with a particle size of 0.005 μm was deposited on the surface of the filter. As a source of ultraviolet radiation, lamps (5) of soft ultraviolet radiation A with a power of 36 W (Phillips PL-L Cleo 36W, 400 mm long) were used.

This device according to the prototype was tested on a stand, a diagram of which is shown in figure 2:

1 - sealed glass box with a volume of 10 m ³ ; 2 - photocatalytic device; 3 - dispenser model pollutants; 4 - a device for measuring the concentration of CO ₂ Klimalogger KL 201; 5 - personal computer. The efficiency of the device was estimated by the rate of accumulation of CO ₂ formed as a result of photocatalytic oxidation of acetone vapor. To measure the rate of accumulation in a sealed chamber (1) with a volume of 10 m ³ was placed the device assembled according to the prototype (2). Using dispenser (3), 5.8 g of acetone was introduced into the chamber, then the device under test was turned on, and the process of increasing the concentration of carbon dioxide (CO ₂ ) resulting from the photocatalytic oxidation of acetone vapor was observed at room temperature. To measure the concentration of CO _{2, we} used the Klimalogger KL 201 instrument (4) connected to a personal computer (5). The CO ₂ formation rate measured for 1 hour for the device under test was 17.9 · 10 ^-5 mol / min.

Example 2

Similar to example 1, with the difference that acetone was not introduced into the chamber. The CO ₂ formation rate measured for 1 hour for the device under test was 0.7 · 10 ^-5 mol / min.

Example 3

Similar to example 2, with the difference that in addition to measuring the concentration of CO ₂ , the concentration of formaldehyde was controlled. The formaldehyde concentration measured after 1 hour for the test device was 182 · 10 ^-6 μg / m ³ .

Example 4

An air purifier with a photocatalytic filter assembled according to the scheme (Fig. 3) of this application includes a dust filter (1), an aerosol charging device (2), a fine filter (3), a photocatalytic filter (4), ultraviolet lamps (5), a unit decomposition of superoxides (6), power and control unit (7), fan (8), purifier body (9), external side mesh shell of the photocatalytic filter (10), photocatalytic element in the form of a backfill from fragments of arbitrary shape, sintered from glass balls with photocatalytic powder coating titanium dioxide having a particle size of 0.005 micrometers (11), an inner side retina photocatalytic filter (12); the upper end cap of the photocatalytic filter (13); bottom end cap of the photocatalytic filter (14).

The test procedure for the air purifier with a photocatalytic filter according to this application was similar to Example 1. The CO ₂ formation rate measured for 1 hour for the claimed utility model of an air purifier with a photocatalytic filter was 17.3 · 10 ^-5 mol / min.

Example 5

Similar to example 3, with the difference that acetone was not introduced into the chamber. Measured in 1 hour the rate of formation of CO ₂ for the tested device was less than 5 · 10 ^-7 mol / min.

Example 6

Similar to example 2, with the difference that in addition to measuring the concentration of CO ₂ , the concentration of formaldehyde was controlled. The formaldehyde concentration measured after 1 hour for the device under test was less than 10 · 10 ^-6 μg / m ³ .

As can be seen from a comparison of the obtained test results, the efficiency of the proposed utility model of an air purifier with a photocatalytic filter from filling fragments sintered from glass balls is approximately the same compared to the known prototype with a photocatalytic filter from coarse fiber lavsan. But at the same time, no formaldehyde is released and no traces of any interaction of the photocatalyst with the material of the photocatalytic filter are detected. A new utility model of an air purifier with an advanced photocatalytic filter can be used in the production of this class of air purifiers.

Example 7

Tests of air purifiers made according to the prototype and according to this application in terms of air disinfection were carried out in a box with a volume of 10 m ³ (1), shown in figure 2. Before each new test, accompanied by a change in the air purifier, the box was treated with a 0.33% analyte disinfectant solution and irradiated with open type portable bactericidal lamps for 1 hour. Tests began 1 hour after completion of the preparatory work.

An aerosol of Escherichia coli bacteria was used as a model pollutant. Spraying of this pollutant was carried out using a replaceable sprayer RJ-4M (3). In order to slow down the settling of the aerosol of bacteria on the walls of the box, a portable fan was used to maintain the initial high concentration of bacteria in the air for at least 100 minutes at the level of 3000 CFU / m ³ (CFU - colony forming units), which was confirmed by preliminary measurements.

To determine the quantitative content of bacteria in the air during the operation of the test device in the box, an impactor for sampling air (Flora-100 model) was used in automatic mode with the selection of a given volume of air of 33 liters and the deposition of microorganisms contained in it on a Petri dish with a dense nutrient Wednesday. The table shows the comparative results of the prototype (figure 1) and the device proposed in this application (figure 3) for air disinfection using the model bacterial contaminant as an example.

Table.
Comparative data on air disinfection. Photocatalytic device The effectiveness of disinfection (%) Prototype device 66.7 Suggested device 99.9

As can be seen from the table, the proposed air purifier device with a photocatalytic filter can be used in a new series of photocatalytic purification and disinfection devices for air and other gases to solve a wide range of domestic and technical problems.

The technical result of this utility model is expressed:

1. In improving the efficiency of the purifier for air disinfection and its purification from molecular chemical and biological pollutants.

2. In increasing the resource of continuous operation of the photocatalytic filter.

The essential features of the proposed utility model, ensuring the achievement of a technical result:

1. The photocatalytic filter includes the following main parts:

outer shell, photocatalytic element and ultraviolet lamps in a quartz case.

2. The outer shell of the photocatalytic filter is made in the form of a protective metal mesh with cells that prevent leakage of backfill.

3. The photocatalytic element is made in the form of a filling that fills the entire space inside the shell.

4. The filling is made of fragments of arbitrary shape with a size of 10-30 mm, sintered from glass balls with a size of 0.8-1.5 mm.

5. The surface of the glass beads is covered with anatase-modified TiO ₂ powder with nanosized particles in the specific surface area range of 100-400 m ² .

6. Ultraviolet lamps, each in a quartz case, are immersed in the backfill.

The proposed photocatalytic filter instead of the coarse-fiber dacron filter is equipped with the well-known prototype air purifier, while the components in the proposed utility model of the air purifier with the new photocatalytic filter are arranged not only in the floor version, but also in the wall and ceiling versions. A new utility model of an air purifier with an advanced photocatalytic filter can be used in the production of this class of air purifiers.

Claims (5)

1. An air purifier with a photocatalytic filter, comprising a dust filter, an aerosol charging device, a fine filter, characterized in that the photocatalytic filter includes external and internal side shells, upper and lower end caps, a photocatalytic element in the form of a filling that fills the entire space inside the shells , and ultraviolet lamps with an ultraviolet range of "A" immersed in the inner side shell, as well as a superoxide decomposition unit and a fan. 2. The air purifier according to claim 1, characterized in that the outer and inner side shells of the photocatalytic filter are made in the form of enclosing metal grids with cells that prevent leakage of backfill. 3. The air purifier according to claim 1, characterized in that the upper and lower end caps of the photocatalytic filter are made deaf to ensure the passage of the cleaned air only through the outer and inner side shells. 4. The air purifier according to claim 1, characterized in that the filling is made of fragments of arbitrary shape with a size of 10-50 mm, sintered from glass balls with a size of 0.8-1.5 mm 5. An air purifier according to claim 4, characterized in that the surface of the glass beads is coated with a powder of anatase-modified nanosized particles of TiO ₂ .