Modular photocatalytic apparatus for use in a ir purification processes

Description of the invention

The present invention relates to a modular photocatalytic air purification device, a fan convector and a method of operation of a fan convector.

Most of the fan convectors consist of a water coil or direct expansion coil, a blower and an air conditioned air distribution channel system. Before heating or cooling, the air is directed through some kind of filter. There are different types of filters. One type of filter is called a substance retaining filter. The filter traps dust and other solid particles. After long-term use, such filters become clogged and need to be replaced.

Another type of filter in use today is known as the HEPA filter. HEPA stands for "high efficiency particulate air". HEPA filters can trap 99.9% of all particles, including submicron particles. Such filters effectively reduce the effects of bioaerosols and dust. They are now used in hospitals, clean production rooms, and other applications where clean air is important. Usually HEPA filters have a service life of 24 months. The efficiency then decreases significantly and the HEPA filters must be replaced.

Another type of filter currently in use is activated carbon adsorption filters. These filters were developed in response to industrial emissions of volatile organic compounds. In an activated carbon adsorption system, the polluted air is directed through the carbon bed. Carbon extracts volatile organic compounds from the air and adsorbs them, keeping them on its surface. The problem with activated carbon adsorption filters is that the filtered air stream cannot have a high moisture content because the carbon adsorbs the moisture. Air with high moisture content will quickly exhaust the coal bed capacity. Secondly, the filtered air must not contain a large amount of solid particles. Such particles will also clog the carbon bed. An activated carbon adsorption filter may therefore require the use of a prefilter to reduce the particulate content and a desiccant to reduce the moisture content.

You need an air filter that essentially eliminates odors, volatile organic compounds, and bioaerosols from the mass of air without requiring extensive service or maintenance. There is a need for a photocatalytic air purification device that can be conveniently installed and removed for maintenance.

The present invention relates to a photocatalytic air purification device that can be conveniently mounted and removed for maintenance. The photocatalytic purification device of the present invention substantially removes unpleasant odors, volatile organic compounds and bioaerosols from air that is directed through a duct or fan convector. The photocatalytic purification device of the present invention is suitable for both industrial and residential applications and can be installed either in original equipment or in addition to existing installations.

One aspect of the present invention is a modular photocatalytic air purification device. The device comprises a modular housing with a reverse positioning mechanism. The upside down positioning mechanism is designed to move the modular housing between a work position aligned with the fan convector and a rest position. A plurality of support structures are disposed in the module of this housing, each of which has a catalytic layer deposited thereon. At least one ultraviolet lamp is placed between these plurality of support structures.

The deflected positioning mechanism includes a hinge door structure that is deflected to provide access to the modular photocatalytic air purification device and an arm for holding the modular housing in an operative position that is detachable when the modular housing is in its rest position.

Preferably, the catalytic layer is composed of titanium dioxide.

It is also advantageous for the support structures to be made of a ceramic fiber substrate.

It is also advantageous when the support structures are made of a non-combustible substrate.

Another advantage is when the support structures are made of an aluminum substrate.

According to another aspect, the present invention comprises a fan convector having an air return, a coil, a blower and an air supply. This fan convector comprises at least one modular photocatalytic cleaning device located at the coil. The at least one modular photocatalytic purification device comprises a modular housing having an inverted positioning mechanism. The positioning mechanism is designed to move it between a work position aligned with the fan convector and a rest position. Within the modular housing are a plurality of support structures, each having a catalytic layer deposited thereon, and at least one ultraviolet lamp is positioned between the plurality of support structures. A control unit may be coupled to the at least one modular photocatalytic purification device, which turns on the power of the at least one ultraviolet lamp depending on the operating mode of the fan convector.

Preferably, the fan convector comprises a filter for filtering the medium between the at least one photocatalytic cleaning device and the air return path.

According to yet another aspect, the present invention includes a method of filtering air in an air return and air supply unit. The method includes the use of at least one modular photocatalytic purification device. The at least one photocatalytic purifier comprises a modular housing having an inverted positioning mechanism and at least one ultraviolet lamp sandwiched between a plurality of titanium dioxide coated filter structures. The deflected positioning mechanism serves to set the at least one modular photocatalytic purification device into a working position within the assembly. The air is directed from the air return to the at least one photocatalytic purifier. The air pollutants are brought into contact with the titanium dioxide coated filter structures. Ultraviolet radiation is directed from the at least one ultraviolet lamp onto the titanium dioxide coated filter structures whereby the titanium dioxide coated filter structures are activated to react with pollutants to generate carbon dioxide and water.

In the above method, it is preferred that the air quality modes include an occupied mode in which the control unit turns on power to the at least one ultraviolet lamp and selectively powers the blower on, and an idle mode in which the control unit turns off power to the at least one ultraviolet lamp by adjusting in this case a coil, so as to keep the temperature within a certain range.

It is also preferred in the above method that the busy mode further comprises a demand sub-mode in which the blower and valve are energized and a fulfillment sub-mode in which at least the valve is de-energized.

The invention is illustrated by an embodiment in the drawing, in which Fig. 1 shows the photocatalytic purification device according to the present invention in a top view, Fig. 2 - photocatalytic purification device in section along line 2-2 of Fig. 1, Fig. 3 - element the honeycomb filter of Fig. 2 in a detailed view, Fig. 4 - a schematic view of a fan convector according to a first embodiment of the invention, showing the photocatalytic purification device of figs. 1-3 in the operating position, fig. 5 - a schematic of a fan convector according to a first embodiment of the invention, showing the photocatalytic purification device of fig. 1-3 in a visited position and fig. 6 is a schematic view of a fan convector according to a second embodiment of the invention showing the photocatalytic purification device of Figures 1-3 in a visited position.

Wherever possible, the drawing will use the same reference numbers for the same or similar parts. An embodiment of a photocatalytic purifier 10 according to the present invention is shown in Fig. 1.

The present invention relates to a photocatalytic air purifying device for use in a fan convector or a blower duct. Such a cleaning device has a modular housing with a reverse position adjustment mechanism. The reverse position adjustment mechanism serves to move the housing between a work position located within the blower coil assembly and an upside down position. The photocatalytic cleaning device includes a first honeycomb filter with a catalytic layer deposited thereon. A second honeycomb filter is disposed next to the first filter, the second honeycomb filter also having a catalytic layer disposed thereon. At least one ultraviolet lamp is positioned between the first filter and the second filter. Catalytic layer

It reacts with airborne VOCs and bioaerosols when activated with ultraviolet radiation to oxidize these volatile organic compounds and destroy bioaerosols.

Thus, the photocatalytic purifier according to the present invention substantially eliminates unpleasant odors, volatile organic compounds and bioaerosols from air directed through the fan convector, while minimizing service and maintenance. In addition, the photocatalytic purification device is conveniently installed and dismantled for maintenance.

Fig. 1 is a top view of the photocatalytic purification device of the present invention. This photocatalytic purification device 10 is housed in the housing 102 of the fan convector between the filter 50 and the fan convector 30. The skilled artisan will appreciate that this embodiment of the present invention can also be used in a duct system instead of a fan convector. The photocatalytic purifier 10 includes at least one filter layer 12 with at least one ultraviolet lamp 20 interposed between the honeycomb filter 14 and the honeycomb filter 16. In the embodiment shown in Fig. 1, the second layer 12 'of the photocatalytic purifier is formed by interposing ultraviolet lamps 22 between the filter 16 and the filter 18. Each additional filter 12 increases the efficiency of the purifier 10. The photocatalytic purifier 10 may thus include a plurality of filter layers 12 that include at least one ultraviolet lamp 20 disposed between the honeycomb filters 14 and 16.

Fig. 2 is a sectional view of the cleaning device 10 taken along line 2-2 of Fig. 1. The honeycomb filter element 12 is clearly visible here. Any suitable structure may be used, however, the honeycomb structure of the filter portions 12, 14, and 16 is preferred as air pressure is maintained while air is directed through the purification device 10. The filter portions 12, 14, and 16 include a catalytic coating 120 thereon. As shown in Fig. 2, ultraviolet lamp 20 is positioned to direct ultraviolet light into the interior of components 12 and 14 of the honeycomb filter. As shown in Fig. 2, the cross section of the photocatalytic purification device 10 is the same as that of the casing 102 of the fan convector. The purification device 10 therefore cleans the entire amount of air flowing through the fan convector.

Fig. 3 is a detailed view of the honeycomb filter element 12 showing the catalytic coating 120 and the substrate 122. One skilled in the art will appreciate that any suitable catalytic coating 120 can be applied to the elements 12, 14, or 16, but a titanium dioxide coating is shown as an example. One skilled in the art will also appreciate that any suitable material may be used as the substrate material for the filter elements 12, 14 and 16, but a ceramic substrate is shown as an example. In other embodiments, an aluminum or FeCrAIY alloy substrate is used. Both ceramic and aluminum substrates are desirable in applications requiring non-flammable filter elements. As long as non-flammability is not an issue, the substrate 122 used in the filter elements 12, 14 and 16 may be made of paper. One skilled in the art will also appreciate that any suitable geometry of the substrate may be used. It may be a honeycomb structure, a rib, a mesh, a filter-type structure, a fiber structure, or a filamentous structure.

The photocatalytic purifier 10 uses a photocatalytic oxidation technique to substantially remove odors, volatile organic compounds, and bioaerosols. The air passing through the purifier 10 passes over the catalytic layer 120. In gas-solid photocatalytic oxidation, an air stream containing VOCs is brought into contact with a titanium oxide catalyst disposed on layer 120. Ultraviolet radiation activates the catalyst. Volatile organic compounds react with the activated catalyst and are converted into carbon dioxide and water by oxidation. This process takes place at room temperature. Since the process takes place at room temperature, the operating cost is significantly lower than that of conventional high temperature thermal oxidation equipment. Photocatalytic oxidation destroys many different pollutants in air streams. The filter elements 14, 16, and 18 are not degraded over time by ultraviolet light, so they do not need to be replaced even with prolonged continuous use.

PL 207 010 B1

It should also be mentioned that bioaerosols are also broken down when exposed to ultraviolet radiation.

As shown in Fig. 4, the fan convector 100 includes a housing 102 which is attached to the suspension cover 104. The suspension cover 104 is attached to the roof or other structural component of the building housing the fan convector 100. The fan convector 100 includes a photocatalytic cleaning device 10 which is located in housing 102 between filter 50 and fan convector 30. The fan convector 30 comprises a cold water inlet 34 and a hot water inlet 36. Both the cold water inlet 34 and the hot water inlet 36 have valves (not shown) which are controlled by the controller 110 of the fan convector to thereby regulate heating and cooling in the air-conditioned room. The fan convector 100 also includes a blower 32 which draws the air flow from the return air duct 42 through the photocatalytic purifier 10 and the fan convector 30. This air flow is then directed into the conditioned room via the air supply duct 40. In Fig. 4, the photocatalytic purification device 10 is shown in the operating position adjacent to the filter 50. The photocatalytic cleaning device 10 comprises a modular housing 60 with an inverted alignment mechanism 62. The inverted alignment mechanism 62 is designed to move the housing 60 between a work position when the housing is aligned with the fan convector and an upside down position. In this embodiment, alignment mechanism 62 is constructed as a hinge door. Mechanism 62 includes an arm 64 that is used to hold housing 60 in the operating position. The reversed position is shown in Fig. 5.

It will be apparent to those skilled in the art that modifications and variations can be made to the controller 110 of the fan convector according to the present invention depending on the cost requirements and the complexity of the application. For example, the fan convector 100 can be used as a standalone unit in a single-family apartment or as one unit among many in multi-family housing. For example, a fan convector 100 may be used in a multi-storey building having multiple air-conditioned zones. The fan convector controller 110 has firmware containing the control program needed to control the water valves, the blower 32 and the ultraviolet lamps 20, 22 and 24 contained in the photocatalytic purifier 10. The control program is executed by a microprocessor contained in the fan convector controller 110. In another embodiment, the fan convector controller 110 is implemented using a logic controller.

The fan convector controller 110 has several operating modes. The first mode of operation is "vacant mode". In this mode, the comfort level provided by the fan convector 100 does not have to be the optimal level as there is no one in the air-conditioned room. The heating and cooling of the air-conditioned room is regulated according to a wider "dead band". The controller 110 allows the ambient air temperature of the conditioned area to vary over a wide temperature range before heating or cooling is provided. In this operating mode, the ultraviolet lamps do not work.

The second mode of operation is called "busy mode". In this operating mode, the comfort level provided by the fan convector 100 is optimized by the presence of people in the air-conditioned room. In this operating mode, the ultraviolet lamps always work. The busy mode includes a "need" sub mode in which the blower 32 runs at a higher speed, and a "satisfied" sub mode in which the blower 32 runs at a slower speed. In other embodiments, controller 110 uses a "tolerance index" as the control metric. The controller 110 may have a motion detector input to determine if the conditioned room is occupied.

The controller 110 also provides a third mode of operation. This is "frost protection mode". The frost protection mode starts heating the air-conditioned room only in order to maintain the minimum air temperature in the air-conditioned room. As the air-conditioned room is assumed to be unoccupied, ultraviolet lamps do not work in this operating mode. In addition to the temperature sensors, the controller 110 may include a sensor input coupled to the window contacts for recognizing the condition of the window being open. In another embodiment, the anti-freeze mode starts heating during the open state of the window.

Figure 5 shows schematically a fan convector 100 with the photocatalytic cleaning device 10 in an upside down position. In this position, an inverted hinge

The door 62 is visited to provide access to the cleaning device 10 during maintenance or when the cleaning device 10 is removed. On removal, the arm 64 is disengaged from the cleaning device 10.

Fig. 6 shows a schematic view of a photocatalytic purification device 100 according to a second embodiment of the invention. In this embodiment, the purification device 100 is disposed in the cabinet 70. Enclosure 60 of the photocatalytic purification device 10 is in the visited position. The shield 60 is provided with a slider 72 on the top of the shield 60 and has a slider 74 on the bottom of the shield 60. One skilled in the art will appreciate that the device 100 can be a fan convector or part of a duct system.

It is obvious to those skilled in the art that various modifications and variations can be made to the invention without departing from the spirit and scope of the invention. The present invention covers such modifications and variations of the invention as fall within the scope of the appended claims.