WO2005075000A1

WO2005075000A1 - Reactor unit for air-purifying and air purifier comprising the same

Info

Publication number: WO2005075000A1
Application number: PCT/KR2005/000348
Authority: WO
Inventors: Ba Do Lee
Original assignee: Ba Do Lee
Priority date: 2004-02-09
Filing date: 2005-02-04
Publication date: 2005-08-18
Also published as: KR20050080240A; CN1917907A

Abstract

The present invention relates to a reaction unit for air cleaning and an air cleaner comprising the same. It provides a reaction unit for air cleaning comprising a main body having pluAral longitudinal passages therein or consisting of a core having pluaral longitudinal passages therein and a casing covering the outer wall of the core; optionally catalyst deposited on the wall of the passages; and an air supplying means connected to the open inlets of the passages for supplying air to the passages. It, also, provides an air cleaner for removing contaminants in the air by adsorption, oxidation, and/or oxidation-reduction comprising the above-mentioned reaction unit, supporting or housing means for the reaction unit and electric power supplying means for the air supplying means. The air cleaner according to the present invention has a compact structure but can remove effectively ozone, aldehydes, volitile organic compounds, hazardous organic compounds, carbon mono-oxide and/or nitrogen oxides as well as microorganisms indoor.

Description

Description REACTOR UNIT FOR AIR-PURIFYING AND AIR PURIFIER COMPRISING THE SAME Technical Field

[1] The present invention relates to a reactor unit for purification of indoor air and an air purifier comprising the same. More particularly, the present invention relates to a reactor unit impregnated with a catalyst which is suitable for use in purifying indoor air or in providing purified air for air conditioning equipments, and an air purifier comprising the same. Background Art

[2] As indoor activities increases, more attention has been paid to indoor air contamination. It has been reported in various publications that contamination of indoor air is far more serious than that of outdoor air.

[3] Contamination of indoor air is partially attributable to incoming of polluted outdoor air. For example, official warnings of ozone, mainly caused by automobile exhaust gas, are often made in metropolises. Microorganisms, such as fungi, mites, bacteria, viruses, etc., acting as pathogens to humans, particularly old and feeble persons, are big factors to contamination of indoor air. In addition, contamination of indoor air is aggravated by HOCs (hazardous organic constituents) and VOCs (volatile organic chemicals) caused by living environment. Serving as a principal cause of sick house syndrome, formaldehyde is air contaminant attracting public attention recently. Allergies, such as child asthma, atopic dermatitis, etc., which are widespread nowadays, have been found to be caused by indoor air.

[4] Of air purification methods, filtering methods are the most popular. However, even HEPA filters for filtration of fine particles, cannot remove move microorganisms. In addition, none of the filters developed thus far provides a function of killing microorganisms. Still worse, if not frequently replaced with a fresh one, a filter used in an air purifier becomes a breeding ground for microorganisms. Further, filtering methods cannot treat ozone.

[5] Besides, air purification using silver particles, photocatalysts, UN light, etc., although frequently advertised in various media, have yet to be proven effective beyond lab conditions in practical use in which contact time is short in a continuous airflow. In addition, the air purification methods have no way of coping with pathogenic viruses such as SARS, influenza, etc.

[6] In contrast, a heat radiation method in which air is brought into to contact with a refractory material heated to a high temperature has the longest history. Indeed, this method successfully removes microorganisms by heat radiation. Modifying the conventional methods, U.S. Pat. No. 4,877,990, issued to Alintor Fiorenzano, disclosed an air sterilizer which comprises a block of refractory material having therethrough a plurality of small diameter ducts provided with axially disposed resistive heating elements which generate high thermal gradients within the ducts to eliminate microorganisms passing through the same.

[7] U.S. Pat. No. 5,874,050, issued to Carlos Matias, suggests a device comprising at least one ceramic elongate member, each member containing a plurality of narrow, parallel passages structured to permit air to flow therethrough, and at least one heating wire disposed within each of the passages, in which the air passing through the passages is heated to be sterilized and exits the passages due to convection.

[8] Matias' patent is different in some non-essential aspects from the Fiorenzano's patent, but is based on the same principle. For example, a difference is that the ceramic members used are somewhat longer, and are thus produced by extrusion, and are disposed in an abutting, tightly clustered arrangement with one another to form a bundle. Other differences are found in the inner space defined by the housing supporting the ceramic members 15 and in the air inlets and outlets formed in the housing. However, Matias'patent, despite being improved in use and has more complex structure than does Fiorenzano's.

[9] The airflow in the above conventional patents depends only on the convection of heated air, which utilizes a large temperature difference between upper and lower portions of the ceramic members. Thus, air contacts the ceramic walls heated to appropriate temperatures only for a short time period. The ceramic heat radiation methods, although more reliably removing microorganisms, especially viruses, require heating to a temperature higher than the combustion temperatures of contaminants such as VOCs, and are thus disadvantageous in energy efficiency and in that they increase the indoor temperature. Disclosure of Invention Technical Problem

[10] An object of the present invention is to provide a reactor unit which is suitable for use in purification of indoor air contaminants including pathogenic microorganisms, by adsorption.

[11] It is another object of the present invention to provide reactor unit, which is used to purify indoor air contaminants including pathogenic microorganisms by heat radiation.

[12] It is a further object of the present invention to provide a reactor unit, which is used to purify indoor air contaminants including pathogenic microorganisms by oxidation and/or oxidoreduction. [13] It is still a further object of the present invention provide an air purifier of a new type which can remove air contaminants including pathogenic microorganisms, ozone, HOCs, VOCs, CO, NO and/or formaldehyde causing sick house syndrome. Technical Solution

[14] In order to accomplish the above object, the present invention provides a reactor unit for air purification, comprising:

[15] a monolithic main body having a plurality of longitudinal passages therein, or a main body consisting of a core having a plurality of longitudinal passages therein, optionally a thermally insulating member wrapping the core and a casing for housing the insulating member; an air intake means including a fan directly or indirectly connected to an air inlet end of the main body at a upstream position from the main body in an air stream; optionally, a filter cartridge, directly or indirectly connected to the air intake means at a upstream position from the main body in the air stream; and optionally, an anion generator, directly or indirectly connected to an air inlet end of the main body at a upstream position from the main body in the air stream.

[16] The heater is installed in front of the fan, that is, downstream of the airflow caused by the fan. Preferably, the heater is directly connected to the fan. Also, the heater may be formed integrally with the fan.

[17] As a material for the monolithic main body or core, which has a plurality of longitudinal passages therein, ceramic is used, but the present invention is not limited thereto. The main body or core may be made from various materials, such as metal, wood, carbon, glass and plastics, depending on working conditions such as temperature. In addition, the material for the main body may be porous aerogel made of metal or quasi-metal oxides.

[18] The longitudinal passages are not specifically restricted in their shape if they afford smooth airflow and sufficient contact area with the airflow therethrough. For instance, the passages are formed as a honeycomb structure in which each cell, having a hexagonal or rectangular cross section, is defined by thin walls so as to increase the contact surface area, or as a three-dimensional network structure. Alternatively, each of the longitudinal passages may have a circular cross section. The term "longitudinal" used herein, means the direction in which air flows, not a longer direction.

[19] As described above, it is preferred that the main body or core be monolithically made from ceramic. Ceramic honeycomb with thin partition walls made by extmsion is disclosed in U.S. Pat. No. 3,790,654 and U.S. Pat. No. 3,824,196 issued to Benbow, et al. Alternatively, a molding method may be employed in which rods or inserts are inserted at the positions for the passages, thereby making it possible to prepare far more complex and precise structures. Also, a technique disclosed in U.S. Pat. No. 3,112,814, issued to Hollenbach, may be used to make honeycomb structure. According to the technique, corrugated organic or inorganic films or weaved tapes are laminated so as to form honeycomb. It is coated with ceramic slurry, dried and sintered. Recently, catalyst-impregnant purifiers for automobile exhaust gas have been prepared by constructing a honeycomb with a tape made from metal, ceramic or glass fibers durable at the usage temperature and by coating a certain ceramic and/or precious metal as a catalytic ingredient on the inner walls of the longitudinal passages of the honeycomb.

[20] In terms of durability and heat efficiency, ceramic material preferably has a balanced combination of strength and heat insulation properties. The ceramic material for the main body and a sintering method therefor are well known in the art. The ceramic material may be selected from a broad range of materials. For instance, a ceramic material (feldspar+sand) is mixed and kneaded with a binder (clay) and the mixture is molded in a mold under pressure. After being dried, the molded article is glazed, baked and sintered. Optionally, primary baking may be conducted at 600-900°C, followed by secondary baking at higher than 900°C.

[21] When the ceramic main body itself is used as a catalyst support, primary baking or heating at a relatively low temperature is preferable since ceramic particles are sintered at high temperatures with result of decrease in surface area. Since the ceramic main body may determine the appearance of an air purifier in the present invention, a glaze may be applied to the surface of the ceramic main body.

[22] Relatively low working temperatures (at most 400°C) make it possible to use usual ceramic materials for the ceramic main body. Ceramic materials suitable for use in the main body include various metal or quasi-metal oxides, nitrides and/or carbides. The ceramic main body may be made from a c omposite of various materials. In order to realize a ceramic main body which is of high strength and has many passages so as to have high heat efficiency, fine ceramics of high purity, such as alumina, silica, etc., may be used. Also, a complex ceramic, such as cordierite, mullite, or aluminosilicate, may be used. These techniques are well known in the art of honeycomb production.

[23] When a ceramic main body is an aerogel, a sol, which may be prepared according to one-step method disclosed in U.S. Pat. No. 2,249,767, issued to Kisler, U.S. Pat. No. 3,672,833, issued to Teichiner et al., U.S. Pat. No. 402,927, issued to Dardel, which improves transparency by addition of a base catalyst, or U.S. Pat. No. 4,610,863, issued to Tewari et al., which replaces a solvent alcohol with CO2, or two-step method disclosed in U.S. Pat. No. 5,409,683, issued to Tillotson et al., may be used. This sol is inserted into a mold and heated at a reduced pressure and a temperature that are above the critical point of a solvent used, followed by extracting the solvent to yield a porous aerogel main body. [24] The main body may be also made from carbon and its analogues. Articles may be formed of active carbon according to the methods of Japanese Pat. Laid-Open Publication Nos. 49-115110 and 3-42039 and Korean Pat. Laid-Open Publication No. 2002-64170 in which mixtures of active carbon powder and a phenol resin, a melamine resin or methylcellulose are used. Upon molding, inserts are disposed in a mould to form a plurality of longitudinal passages. Wood charcoal may be also used. In this case, mechanical work such as drilling is conducted to form longitudinal passages of circular section.

[25] Also, the main body may be a fabricated zeolite. A method of producing a fabricated zeolite from a mixture of zeolite powder and a metal or quasi-metal oxide is disclosed in DE3738916A.

[26] During the intake of air in a cool wind mode, the carbon or zeolite article can be used as an adsorbent of contaminants. When the adsorbent is saturated with contaminants, it can be periodically regenerated by oxidizing the contaminants in a hot wind mode.

[27] A main body without incorporation of catalysts is also included within the scope of the present invention. This is because the inner walls of the longitudinal passages of the ceramic main body, including the longitudinal passages, are heated by a blower (heater with a fan) and still function to purify air by their combustion effect.

[28] On the inner walls of the longitudinal passages of the main body, a catalyst may be coated using various methods. The kind of catalyst depends on the usage temperature of the catalyst, and the kind of contaminants. A low temperature-active catalyst system is preferable in terms of energy efficiency and durability.

[29] A number of catalysts capable of removing VOCs, aldehydes, and mercaptans from room temperature to a relatively low temperature (250°C or less) are known.

[30] In Korean Pat. No. 336963, zeolite impregnated with palladium ions, together with copper, manganese, nickel, chrome and cobalt ions, is calcined to produce a powder. This powder is slurried with an inorganic binder and the slurry is coated on a support which is then used to remove VOCs at 200°C.

[31] Japanese Pat. Laid-Open Publication No. 6-210721 disclosed air purification at 150°C by catalysts of a precious metal and a metal oxide, such as ceria, zirconia or titania, are deposited in combination.

[32] U.S. Pat. No. 6,492,298 suggests a catalyst comprising a precious metal-mounted metal or quasi-metal oxide, which is able to remove aldehyde mercaptans at room temperature.

[33] U.S. Pat. No. 5,538,931 describes a catalyst active at relatively low temperatures, which has a transition metal and a chelating agent comprised in an aerosol.

[34] Catalysts containing precious metals, manganese dioxide, or copper oxides as catalytic ingredients are found to convert ozone to oxygen.

[35] According to the present invention, a precious metal selected from the group consisting of Pt Group metals, Ag, Au, Mn and St, and preferably from the group consisting of Pt, Rh and Pd, and/or a metal or quasi-metal oxide selected from the group consisting of iron oxides, ceria, zirconia, copper oxides, rare earth metal oxides, manganese oxides, vanadium oxides, and chrome oxides are preferably deposited on the inner walls of the longitudinal passages through the main body. The precious metals may be coprecipitated with the oxides or mounted on the oxides, ceramic materials, or zeolite. Pd or Pt, and manganese oxide are Preferable. A manganese oxide and a Pd- or Pt-mounted ceria or zirconia are the most preferable.

[36] Methods of depositing catalytic ingredients on the ceramic main body are well known. For example, the ceramic main body is immersed in an aqueous solution of metal or its water-soluble salt such as palladium chloride and the catalytic ingredient is dried and reduced. Coating of ceramic materials, such as metal or quasi-metal oxides, may be achieved by wash-coating 20 the main body with a slurry comprising an inorganic or organic binder through immersion or spraying, and baking the slurry, or by immersing the ceramic main body in a solution of metal or quasi-metal, drying and calcining.

[37] In the case that the main body is formed of active carbon or zeolite, a powder impregnated with catalysts may be made before molding, as described in Korean Pat. No. 336963.

[38] Since air introduced into the main body needs to be heated when the deposited catalyst is active at room temperature or when the main body itself serves as an adsorbent, a reactor unit employing a fan not provided with a heater, instead of a heat blower, is also included within the scope of the present invention. Except for this special case, the air intake means according to the present invention comprises a fan, directly or indirectly connected to an inlet of the longitudinal passages, for supplying air to the longitudinal passages, and a heater, connected to the fan directly or indirectly, for heating the supplied air in front of the fan. Accordingly, the heater is typically positioned in front of the fan, that is, downstream of the fan in airflow. Preferably, the heater is directly connected to the fan or integrally formed with the fan. In the present invention, a fan provided with a heater is called a heat blower.

[39] The heater may comprise a coil heating wire or a strip heating wire. The structure of the heat blower is similar to that of a hair drier. The heat blower has a blowhole, which directly or indirectly communicates with an end of the main body so as to supply air to an inlet of the longitudinal passages.

[40] Featuring the present invention, the air intake means plays an important role in the air purification. In an initial working stage, the heat blower accelerates heating the inner walls of the longitudinal passages of the main body or the core to a desired reaction (e.g., oxidation) temperature. After reaching the desired point, the temperature within the longitudinal passages of the main body is maintained. The air taken into the main body is treated and purified. Only by varying the power output of the heater or the speed of the fan (more briefly, just the speed of the fan), the air purification process can be controlled.

[41] The temperatures of the walls of the passages depend on the activation temperatures of the catalysts deposited thereon and are preferably in a range from room temperature to 400°C, with the air from the upper outlet maintained at 150°C or less.

[42] In accordance with the present invention, the reactor unit may further comprise an anion generator. As well known, an anion generator is structured to allow air to pass through a discharging area formed by applying 5 to 100 KV across a cathode and an anode. In order to generate as many anions as possible using a relatively low voltage, the anion generator preferably has a structure in which a perforated plate having a plurality of 15 holes therethrough is positioned in a discharging gap away from another perforated plate having a plurality of corresponding discharging needles formed thereon, rather than a simple structure. In addition to the two opposite polar plates, the anion generator comprises an electric circuit, a controller, and a voltage converter.

[43] Together with anionic air, ozone is generated by the anion generator. The amount of ozone generated is proportional to the voltage applied. Ozone, although serving to block UV rays in an upper portion of the stratosphere, is known to be hazardous to the human body. The FDA has set a limit of 50 ppb for ozone in a room. As air passes through the longitudinal passages of the reaction unit, the ozone generated by the anion generator is efficiently removed. Pt Group metal or manganese dioxide is known to catalyze a change from ozone to oxygen. It is preferable that the anion generator be positioned between the blowhole of the air intake means and the air inlet of the main body.

[44] In accordance with the present invention, the reactor unit may further comprise a filtering means. The filtering means may be a single filter or may consist of a prefilter and a HEPA filter. Preferably, the filtering means is a cartridge structure to be simply disassembled and assembled and to be combined with the air inlet of the heat blower.

[45] In accordance with the present invention, the reactor unit may be used in combination with an air conditioner, located before the inlet or after the outlet of the conditioner. Particularly, the reactor unit of the present invention is suitable for use as an air supply unit in an ultrasonic humidifier. When applied to an ultrasonic humidifier, the reactor unit of the present invention can prevent the proliferation of microorganisms in the non-heating tank.

[46] The present invention also provides an air purifier comprising: the reactor unit; an electric unit comprising a power supply means, including a transformer and a high voltage converter, for supplying power to the reactor unit, and a controlling means for controlling the power supply means; and a housing means for accommodating and supporting the reactor unit and the electric unit is provided. A casing of the reactor unit

[47] may be incorporated into the housing means.

[48] In addition to the power supply means and the controlling means, the electric unit may optionally further comprise a display means for indicating the working state of the reactor unit and/or a sensing means for measuring the temperature, humidity, and/or degree of contamination tamination of air. The power supply means may comprise a plug, a conducting wire, a transformer, and a high voltage converter. As a simple display means, a combination of LEDs in parallel can display the working state of the reactor unit. The simplest controlling means performs a function of switching on and off. With a more complex structure, the controlling means can automatically control the operation of the fan and/or the heater in response to the outlet temperature monitored by a sensor.

[49] According to operation modes selected with a control knob 23, included in the controlling means 22, or according to the outlet temperatures monitored by the sensor, the rotation speed of the fan and/or the power output of the heater can be changed by the controlling means so as to subject the contaminants to oxidation or oxido-reduction or to recover the air purification ability of the reactor unit. For example, in an initial stage just after switching on, the controlling means 22 may lower the rotation speed of the fan and/or elevate the power output of the heater to accumulate heat in the main body 30 or the core 30'. After a lapse of a predetermined time or upon reaching a predetermined temperature, the controlling means shifts the operation of the reaction unit to a working mode to perform air purification.

[50] With respect to the main body formed of active carbon or zeolite, a normal rotation speed of the fan and/or a low or no power output of the heater may be set at an initial or adsorption stage so as for the main body to adsorb contaminants. With the lapse of a predetermined ed time period or according to a degree of contamination monitored by the sensor, the air purifier is shifted from a operation stage to a regeneration stage in which a low rotation speed of the fan and/or a high power output of the heater is set to accumulate heat in the main body 30 or the core 30'. After completion of the regeneration, the air purifier is set back to the initial or adsorption stage. The process is repeated.

[51] In a compact structure, the reactor unit is sustained away from the ground, with the power supplying means and the controlling means being housed therein or mounted thereon. In the case where the outer wall of the reactor unit is used as the exterior wall of the air purifier, a supporting means is further provided to keep the bottom of the reactor unit away from the ground by holding the flanks of the reactor unit, so that air is introduced through the inlet of the reactor unit and is discharged from the reactor unit.

[52] Used in the present invention is a well-known power supply means. Basically, it comprises a plug and an electric wire. Optionally, it may further comprise a transformer for converting voltages. Preferably, an LED may be connected in parallel to the power supply means to display the operation state of the reactor unit. Also, the power supply means may further comprise a switch for switching the reactor unit on and off.

[53] If supported by arms, as will be described below, the power supply means may be formed integrally with the support arms.

[54] In the present invention, the supporting arms are holding flanks of the main body in the manner not to interrupt the flow of air through the main body. If the supporting means has a ring type holder, a groove or a protrusion fitting to the holder is preferably formed along an outer circumferential surface of the main body.

[55] In a simple structure requiring no additional housing, the air inlet of the main body can be sustained away from the ground by one of two methods.

[56] First, a ground support method is explained. This method may be divided in a fixed type and a separable type. As a supporting means on the ground, a holder formed on outer circumferential surface of the main body for holding up the main body and the a bridge, connected to the holder, are provided. The bridge may be pivotably mounted on the holder for the convenience of transport or storage.

[57] As a separable type, for example, it comprises a holder ring fitted to a groove formed along an outer circumferential surface of the main body thus supporting the main body and a bridge fixed to the holder, like a flowerpot supporter.

[58] Another example is a truncated cone-shaped structure which comprises a small upper concentric ring for holding the main body, a large lower concentric ring for a base, and a side wall, partially cut out to circulate air combining the upper concentric ring with the lower concentric ring.

[59] Second, an arm supporting structure may be adopted, in which a holder for supporting the ceramic body is fixed to an arm which extends to a plug. This structure ructure can be easily installed at a wall, but has a poor supporting strength with respect to its load. In order to improve the supporting strength, the holder is provided with an additional holder and a subsidiary arm which is fixed to the additional holder and extends in a slanted direction so as to be supported by friction. The arm supporting structure has poor self-supporting performance, but enjoys the advantage of being simple. Advantageous Effects

[60] The air purifier of the present invention can remove not only microorganisms, including viruses, but also ozone, aldehydes, VOCs, HOCs, CO, and other air contaminants, and requires a minimum maintenance effort due to its compact structure. In addition, the air purifier can be produced with economical favor because of the small number of parts and thus can be maintained readily. Brief Description of the Drawings [61] FIG. 1 is a perspective view showing a conventional refractory block having therethrough a plurality of small diameter ducts; [62] FIG. 2 is a partially dissected perspective view showing another conventional assembled air purifier; [63] FIG. 3 is an exploded perspective view showing a reactor unit in accordance with an embodiment of the present invention; [64] FIG. 4 is an assembled cross-sectional view of FIG. 3;

[65] FIG. 5 is a perspective view showing an air purifier employing the reactor unit of FIG. 3; [66] FIG. 6 is an exploded perspective view showing a reactor unit in accordance with another embodiment of the present invention; [67] FIG. 7 is an assembled cross-sectional view of FIG. 6;

[68] FIG. 8 is a perspective view showing an air purifier employing the reactor unit of FIG. 6; [69] FIG. 9 is an exploded perspective view showing a reactor unit in accordance with a further embodiment of the present invention; [70] FIG. 10 is an assembled cross-sectional view of FIG. 9;

[71] FIG. 11 is a perspective view showing an air purifier employing the reactor unit of FIG. 9; [72] FIG. 12 is an exploded perspective view showing a reactor unit in accordance with still a further embodiment of the present invention; [73] FIG. 13 is an assembled cross-sectional view of FIG. 12;

[74] FIG. 14 is a perspective view showing a corresponding perforated plate of an ozone generator assembled in the reactor unit of FIG. 13; [75] FIG. 15 is a perspective view showing a discharging needle-mounted perforated plate of an ozone generator assembled in the reactor unit of FIG. 13; [76] FIG. 16 is a perspective view showing a filter cartridge used in an air purifier of FIG. 18; [77] FIG. 17 is a cross sectional view of FIG. 16;

[78] FIG. 18 is a partially dissected cross-sectional view showing the reactor unit of FIG. 12; and [79] FIG. 19 is a perspective view showing an air purifier employing the reactor unit of FIG. 12. Best Mode for Carrying Out the Invention

[80] With reference to the drawings, a detailed description will be given of the present invention, below. It should be understood that reactor units employing only a heater directly connected to or integrated with a fan (called "a heat blower) are explained, but the present invention is not limited thereto.

[81] FIG. 1 shows an air sterilizer which comprises a refractory block 4 having therethrough a plurality of small diameter ducts 3 provided with axially disposed resistive heating elements which generate high thermal gradients within the ducts to eliminate microorganisms passing through the same. A box or case is adopted to house this air sterilizer and a means for mounting the system on the wall of an enclosure so as to secure an influx path in the bottom is provided. This structure is not convenient to use.

[82] FIG. 2 is an air sterilizing device comprising a housing 126 for a ceramic heating bundle consisting of a plurality of extrusion-molded, elongate ceramic members 152, each containing a plurality of narrow, parallel passages 150 within which heating wires are disposed. Within the housing, the heating bundle is supported by a disk fixed a predetermined distance from the bottom. The heating wire is connected to an electric line disposed at a lower end of the housing. Air is introduced through a slit formed at a lower portion of the housing and heated within the passages to rise naturally and exit through the longitudinal passages of the elongate ongate member, drawing a new supply of unsterilized air into the passages.

[83] Matias' patent (FIG. 2) is different in some non-essential aspects from Fiorenzano's patent, but is based on the same principle (FIG. 1). For example, one difference is that the ceramic members used are somewhat longer, and are thus produced by extrusion, and are disposed in an abutting, tightly clustered arrangement with one another to form a bundle. The inner space defined by the housing supporting the ceramic members and the air inlets and outlets formed in the housing are different from Fiorenzano's. However, Matias' patent, despite being improved in usability and has more complex structure than Fiorenzano's.

[84] With reference to FIGS. 3 and 4, a reactor unit for air purification is shown in accordance with an embodiment of the present invention. As seen in the figures, for the reactor unit for air purification a ceramic main body 30 having a rectangular honeycomb structure 41, which is monolithically formed and baked may be coated with an active catalyst on the inner wall of the longitudinal passages. This catalyst may include a precious metal as a catalytic ingredient and a reducible metal oxide as a 25 support, as disclosed in WO91/01175. Catalyst is applied on the inner walls of the longitudinal passages of the honeycomb by a slurry method (wash coating) and is then baked. On an outer circumferential surface of a middle portion of the ceramic main body 30, a protrusion ring 32 having a predetermined width is provided to be supported by a holder 91 'of a ring type support 91. At the lower end of the ceramic main body 30, an external screw 55 is formed. With an internal screw 56 for engaging with the external screw 55, the fan 51 is associated with the ceramic main body 30 to construct a reactor unit 81 of the present invention.

[85] FIG. 5 shows an air purifier employing the reactor unit of FIGS. 3 and 4, in accordance with an embodiment of the present invention. In this embodiment, the reactor unit is further provided with a power supply unit including a plug 21, an electric wire 25, a switch 26, and an LED display 27 for indicating an ON or OFF state. Support 91 of a flowerpot supporter type has a ring-shaped holder 91' which is adapted to support the protrusion ring 32 and thus hold up the reactor unit.

[86] With reference to FIGS. 6 and 7, a reactor unit is shown in accordance with another embodiment of the present invention. As seen in the figures, a ceramic main body 30 of the reactor unit having a rectangular honeycomb structure 41 is monolithically formed and baked. On an outer circumferential surface of a middle portion of the ceramic main body 30, a protrusion ring 32 having a predetermined width is provided to be supported by a holder 91 ' of a ring type support 91. At the lower end of the ceramic main body 30, an external screw 55 is formed, through which the ceramic main body 30 is combined with a heat blower 50. With an internal screw 56 for engaging with the external screw 55, the heat blower 50, which comprises a fan 53 and a coil heater 52 disposed in front of the fan 53, is engaged into the ceramic main body 30. In this embodiment, the reactor unit may not include a catalyst. In order to heat the inner wall of the longitudinal passages of the honeycomb structure to a temperature high enough to sterilize microorganisms and oxidize contaminants, the heating coil generates hot air which is blown by the fan. Preferably, the honeycomb structure has a low temperature-active oxidation or oxidation-reduction catalyst deposited thereon, so as to remove microorganisms or contaminants at low temperatures. The heat blower is designed to control the output according to the activation temperature of the catalyst deposited and the oxidation temperature of contaminants.

[87] FIG. 8 shows an air purifier employing the reactor unit of FIGS. 6 and 7, in accordance with another embodiment of the present invention. In this embodiment, the reactor unit is further provided with a power supply unit including a plug 21, an electric wire, a switch 26, and an LED display 27 for indicating an ON or OFF state. A four-legged support 92 has a ring-shaped holder 92' which is adapted to support the protrusion ring 32 and thus hold up the reactor unit.

[88] With reference to FIGS. 9 and 10, a reactor unit 83 is shown in accordance with a further embodiment of the present invention. As seen in the figures, the reactor unit comprises a ceramic main body 30, monolithically formed and baked. It has a pluraUty of narrow, parallel passages 43 having circular sections. A catalyst is deposited on the inner wall of the passages. At the lower end of the ceramic main body 30, an external screw 55 is formed, through which the ceramic main body 30 is combined with a heat blower 50. With an internal screw 56 for engaging with the external screw 55, the heat blower 50, which comprises a fan 53 and a coil oil heater 52 disposed in front of the fan 53, is associated with the ceramic main body 30. The reactor unit 83 includes a filter cartridge 60 which is combined with the heat blower 50 in the same manner as in the combination of the heat blower with the ceramic main body. In the filter cartridge 60, a pre-filter 61, a first grid 62, a void 63, a HEPA filter 64 and a second grid 65 are formed, in ascending order from the bottom.

[89] FIG. 11 shows an air purifier employing the reactor unit of FIGS. 6 and 7, in accordance with a further embodiment of the present invention. In this embodiment, the reactor unit 83 is further provided with a power supply unit including a plug 21, an electric wire, a switch 26, and an LED display 27 for indicating an ON or OFF state. A support 93 has two facing fixtures 93 which are rotatably combined with corresponding grooves 96 which are formed in opposite walls of the ceramic main body 30.

[90] With reference to FIGS. 12 to 17, a reactor unit 80 is shown in accordance with still another embodiment of the present invention. As seen in the figures, the main body 30 consists of a ceramic core 30' and a thermally insulating member 35 wrapping the ceramic core 30' and a casing(38). The ceramic core 30' is monolithically extruded and baked, and has a hexagonal honeycomb structure 45. on of which a low temperature- active catalyst is deposited on the inner wall of the longitudinal passages. An anion generator 70, which includes a pair of grids 71, with a perforated plate 72 having a plurality of discharge needles, an insulation plate 73 and a corresponding perforated plate 74 disposed therebetween in ascending order from the bottom, is attached to the lower end of the casing 38. Subsequently, a heat blower 50 which comprises a fan 53 and a coil heater 52 disposed in front of the fan 53, is combined with the lower end of the anion generator 70 through a screw engagement.

[91] FIG. 16 shows a filter cartridge 60 consisting of a prefilter 61, a first grid 62, a void 63, a HEPA filter 64 and a second grid 65, in order from the outside. The filter cartridge 60 is connected to an inlet of the heat blower 50 through a conduit 65 formed in an additional housing.

[92] FIGS. 18 and 19 show an air purifier employing the reactor unit of FIGS. 6 and 7, in accordance with a further embodiment of the present invention. In this embodiment, the reactor unit 80 is installed in a housing, along with a power means 28 including a transmitter and a high- voltage converter and a control means 22 for controlling the power and ON/OFF switching. On an outer surface of the housing, a control knob 22 is provided for setting working conditions, such as the temperature of the effluent air, the air volume of the heat blower, the temperature of the coil heater, etc. The housing is further provided with a power supply unit including a plug 21, an electric wire 25, a switch 26, and an LED display 27 for indicating an ON or OFF state. The filter cartridge 60 is connected to an inlet of the heat blower 50 through a conduit 65 formed in the housing.

Claims

[1] A reactor unit (80, 81, 82, 83) for air purification, comprising: a monolithic main body (30) having a plurality of longitudinal passages therein, or a main body (30) consisting of a core (30') having a plurality of longitudinal passages therein, optionally a thermally insulating member (35) wrapping the core and a casing for housing the insulating member; an air intake means (50, 51) including a fan (53) directly or indirectly connected to an air inlet end of the main body (30) at an upstream position from the main body (30) in an air stream; optionally, a filter cartridge (60), directly or indirectly connected to the air intake means (50, 51) at aupstream position from the main body(30) in the air stream; and optionally, an anion generator (7), directly or indirectly connected to an air inlet end of the main body (30) at an upstream position from the main body(30) in the air stream.

[2] A reactor unit (80, 81, 82, 83) as set forth in claim 1, wherein the air intake means (50) further comprises a heater (52) directly or indirectly connected to the fan (53) at a upstream position of the main body (30) in the air stream.

[3] A reactor unit (80, 81, 82, 83) as set forth in claim 2, wherein the heater (52) is directly connected to the fan (53) at a downstream position of the fan (53).

[4] A reactor unit (80, 81, 82, 83) as set forth in claim 1, wherein the longitudinal passages (41, 43, 45) are formed as a honeycomb structure in which parallel cells, each having a circular, hexagonal or rectangular cross section, are formed, or as a three-dimensional network structure.

[5] A reactor unit (80, 81, 82, 83) as set forth in claim 3, wherein the main body (30) or the core (30') is made from ceramic or aerogel.

[6] A reactor unit (80, 81, 82, 83) as set forth in claim 5, wherein the main body 30 or the core (30') is made from aerogel and the inner walls of the longitudinal passages (41, 43, 45) are impregnated with an oxidation or oxido-reduction catalyst.

[7] A reactor unit (80, 81, 82, 83) as set forth in claim 6, wherein the inner walls of the longitudinal passages (41, 43, 45) are impregnated with at least one metal selected from the group consisting of Pt Group metals, Ag, Pd and Mn, and/or at least one metal or quasi-metal oxide selected from the group consisting of iron oxides, ceria, zirconia, copper oxides, rare metal oxides, manganese oxides, vanadium oxides, cobalt oxides and chrome oxides.

[8] A reactor unit (80, 81, 82, 83) as set forth in claim 7, wherein the inner walls of the longitudinal passages (41, 43, 45) are impregnated with the Pt Group metal by being mounted on the metal or quasi-metal oxides, ceramic materials, or zeolite coated on the walls or by being co-precipitated with the metal or quasi- metal oxides coated on the walls .

[9] A reactor unit (80, 81, 82, 83) as set forth in claim 4, wherein the main body (30) or the core (30') is fabricated with carbon or its analogues, or zeolite.

[10] A reactor unit (80, 81, 82, 83) as set forth in claim 9, wherein the inner walls of the longitudinal passages of the main body (30) or the core are impregnated with an oxidation or oxidoreduction catalyst.

[11] A reactor unit (80, 81, 82, 83) as set forth in claim 10, wherein the inner walls of the longitudinal passages (41) of the main body (30), are impregnated with at least one metal selected from the group consisting of Pt Group metals, Ag, Pd and Mn, and/or at least one metal or quasi-metal oxide selected from the group consisting of iron oxides, ceria, zirconia, copper oxides, rare metal oxides, manganese oxides, vanadium oxides, cobalt oxides and chrome oxides.

[12] A reactor unit (80, 81, 82, 83) as set forth in claim 11, wherein the reactor unit is formed by fabrication of carbon particles or its analogues or zeolite particles which are impregnated with the Pt Group metal or the metal or quasi-metal oxide or which are mixed with the Pt Group metal co-precipitated with the metal or quasi-metal oxides.

[13] A reactor unit (80, 81, 82, 83) as set forth in any one of claims 1 through 12, wherein the reactor unit for air purification is used in a humidifier.

[14] An air purifier (100, 101, 102, 103) comprising: a reactor unit (80, 81, 82, 83) according to any one of claims 1 through 8; a housing means (91, 92, 93, 95) for supporting the reactor unit; a power supplying means (20) for supplying an electric power to the reactor unit; optionally, a display means (27) for indicating the operation state of the reactor unit; optionally, a sensor for monitoring the temperature, the humidity, and/or the degree of contamination of indoor air; and optionally, a controlling means (22, 23).

[15] An air purifier The air purifier (103) as set forth in claim 14, wherein, according to operation modes selected with a control knob (23), included in the controlling means (22), or according to the outlet temperatures monitored by the sensor, the rotation speed of the fan (53) and/or the power output of the heater is changed by the controlling means so as to subject air contaminants to oxidation or oxido- reduction or to recover the air purification ability of the reactor unit.

[16] An air purifier (103) as set forth in claim 15, wherein the controlling means (22) regulates a rotation speed of the fan and/or a power output of the heater in an initial stage just after switching on, to accumulate heat in the main body (30) or the core (30') and, after a lapse of a predetermined time or upon reaching a predetermined temperature, the controlling means shifts the operation of the reaction unit to a working mode to perform air purification.

[17] An air purifier comprising : a reactor unit (80, 81, 82, 83) according to any one of claims 9 to 12; a housing means (91, 92, 93, 95) for supporting the 15 reactor unit; a power supplying means for supplying an electric power to the reactor unit; optionally, a display means (27) for indicating the operation state of the reactor unit; 20 optionally, a sensor for monitoring the temperature, the humidity, and/or the degree of contamination of indoor air; and optionally, a controlling means (22, 23).

[18] An air purifier (103) as set forth in claim 17, wherein, according to operation modes selected with a control knob (23), included in the controlling means (22), or according to the outlet temperatures monitored by the sensor, the rotation speed of the fan (53) and/or the power output of the heater is changed by the controlling means so as to subject air contaminants to adsorption, oxidation or oxido-reduction or to recover the air purification ability of the reactor unit.

[19] An air purifier (103) as set forth in claim 18, wherein the controlling means (22) regulates a normal rotation speed of the fan and/or a low or no power output or of the heater in an initial or adsorption stage just after switching on, so as for the main body or the core to adsorb contaminants, then, with the lapse of a predetermined time period or according to the degree of contamination monitored by the sensor, shifts the air purifier from the operation stage to a regeneration stage in which a low rotation speed of the fan and/or a high power output of the heater is set to accumulate heat in the main body 30 or the core 30' and then, after completion of the regeneration, sets the air purifier back to the initial or adsorption stage.

[20] An air purifier (101) as set forth in claim 14, wherein 20 the housing means (91) comprises a support (92) having at least three legs and a ring-shaped holder (95') for holding a flank (32) of the reactor unit and thus sustaining the reactor unit.

[21] An air purifier (100) as set forth in claim 17, wherein the housing means comprises a truncated cone-shaped structure for supporting the reactor unit, the structure including a small upper concentric ring for holding the main body, a large lower concentric ring for a base, and a side wall, partially cut out to circulate air, for connecting the upper concentric ring with the lower concentric ring.

[22] An air purifier (100, 101, 102) as set forth in claim 14, wherein the housing means comprises a supporting means including legs (93), supporting angles extending from the legs, and fixtures (95), formed on the supporting angles, for rotatably holding the reactor unit by being inserted into grooves formed in 10 flanks of the reactor unit.

[23] An air purifier as set forth in claim 14, wherein the reactor unit (80) is supported by the housing means (95), and the power supplying means (28), the controlling means (22) and the 15 display means are cased in the housing means.

[24] An air purifier as set forth in claim 14, wherein the housing means comprises a supporting means which includes a holder for supporting the main body, said holder being provided with an additional holder and a subsidiary arm which is fixed to the additional holder and extends in a slanted direction so as to be supported by friction.