MXPA99006020A - Air treatment device - Google Patents

Abstract

An air treatment device is described that is adapted to be mounted on, and directly supported by, a socket. A treatment medium, such as an electrostatic filter (33), is located at the front of the device. A carefully designed fan (15) draws air through the filter and particles with a particle size above 0.1&mgr;m are removed. When the filter becomes too dirty it is replaced.

Description

APPARATUS FOR. TREAT AIR FIELD OF THE INVENTION This invention relates to an apparatus for treating air and, particularly, to removing contaminants such as particulate materials such as dust or pollen, germs, viruses or air gaseous components for domestic applications.

BACKGROUND OF THE INVENTION Previous apparatuses of this type have been large and bulky, generally greater than 30 or 40 cm between ends. This is because to treat reasonable airflows in a room or office, the product of fan speed and fan area must be large enough and, if a small fan is used, it has to operate at high speed. However, at high speeds fans tend to produce unacceptable noise levels that make them unsuitable for domestic or office applications. On the other hand, filters for such applications that have a sufficient mesh to trap particles no greater than 0.1 μm provide considerable resistance to air flow to provide sufficient air flow to satisfactorily clean the air in a room, such P1377 / 99 air purifiers have traditionally been large to place on a table or even on the floor. There is a need to provide an air treatment apparatus that is adapted to connect directly to an electrical outlet socket and be supported by the plug, in particular, a plug of the electrical distribution network. According to the invention, there is provided an apparatus for air purification, configured for direct connection and supported by a plug of the electric distribution network, the apparatus comprises a purification means, a fan configured to produce an air flow through the purification means, an electric motor for driving the fan, a housing and a plurality of bolts attached to the housing and configured to insert into the plug and provide electricity to the motor in which the fan includes an integrated central cavity configured to accommodate the motor in the central cavity to facilitate the support of the appliance by the plug. In the simplest form, the bolts themselves, which provide electricity and therefore power to the engine, also provide support for the apparatus itself. Alternatively, or in conjunction with the foregoing, the invention provides an apparatus for the P1377 / 99 air treatment, adapted to be plugged directly into an electrical outlet and supported therein, comprising a treatment medium, a fan adapted to make air flow through the treatment medium, a motor for actuating the fan, a housing and a plurality of bolts attached to the housing adapted to fit within the plug and to supply electricity to the motor, wherein the axial thickness of the fan is between 1 and 5 centimeters, preferably between 2 and 4 centimeters. Alternatively, or in conjunction with the foregoing, the invention provides an apparatus for treating air, adapted to be plugged directly into and supported by an electrical outlet, comprising a treatment means, a fan adapted to make the air flows through the treatment means, a motor for driving the fan, a housing and a plurality of bolts attached to the housing adapted to fit within the plug and to supply electricity to the motor, where the motor is adapted, when it is in use, to spin the fan at less than 3000 revolutions per minute. Alternatively, or in conjunction with the foregoing, the invention provides an apparatus for treating air, adapted to be plugged directly into an electrical outlet and supported therein, comprising a treatment means, a P1377 / 99 adapted to cause air to flow through the treatment means, a motor to drive the fan, a housing and at least two, preferably three bolts attached to the housing adapted to fit inside the plug and to supply electricity to the motor, wherein the apparatus is sized to be supported only by the adjustment of the bolts within the electrical socket. In all the above, the motor of maximum convenience is a DC (direct current) motor, which means that for its installation in a normal main line plug must also include means of transformation and rectification of current. Surprisingly, the inventors have found that even with this restriction it is still possible, by careful design, to construct a purification apparatus that can stand on its own, in the elements of a socket. The associated transformer and rectifier can be located on the fan. The local normals determine the maximum size of the articles configured to be supported by a main line plug and in particular the maximum allowed torque to be exerted on the plug. The purification medium is preferably a filter, in particular an electrostatic filter comprising a fine mesh sheet. The fabric for such filters is manufactured appropriately with P1377 / 99 polypropylene, which is electrostatically charged during its manufacture and can be obtained, for example, in 3M. The filter operates by electrostatic attraction on the small particles that pass through it. The filter sheet is, advantageously, corrugated or grooved, not flat, to increase the effective surface of the filter for a given housing size. This pleating also acts to decrease the effective velocity of the air through the filter, so that the electrostatic filter can still trap particles even with relatively high volumetric air flows. Such flow rates are necessary to provide effective air cleaning. Alternatively, for gaseous pollutants the selection of the purification medium will depend on the exact chemical nature of the gas but may include activated carbon or molecular sieves. As noted above and in use, the fan speed is preferably less than 3000 rpm, in addition to preferably between 2000 and 2800 rpm. Above 3000 rpm the noise and the tone of the fan sound become very irritating for use in domestic or office environments. Below about 2000 rpm it is not possible to provide a fan having sufficient flow rate by creating an appropriate differential pressure. Electrostatic filters require differential pressures and volumetric flow rates P1377 / 99 very controlled to operate correctly. In order to achieve an appropriate flow rate, the fan is preferably of the reverse curve impeller type with at least six, preferably between nine and fifteen blades. The reverse curve driver can produce a sufficient flow rate because it is capable of producing a sufficiently high pressure drop across the filter, unlike a conventional fan of the same size. If the number of blades is very small, the fan has to turn very fast to provide an adequate air flow. Too high a number of blades increases manufacturing difficulties and reduces the size of the blade spacing to such an extent that efficiency is not increased by the addition of additional blades. The dimensions of the fan are also preferably selected carefully. If the fan blades are too close to the housing, the amount of noise increases considerably. However, if the fan is too small then it has to operate at higher speeds for the same air flow, which once again increases the noise. Experiments have shown that the outer end of the fan blades must be between 1 mm and 20 mm inside the housing, and preferably between 3 and 8 mm. Normally, the fan will have a diameter of 1 to 14 cm, preferably between 2 and 8 cm. Typically, the fan will have a diameter of 1 P1377 / 99 to 14 cm, preferably between 2 and 8 cm. It will be appreciated that if the fan has an excessive axial thickness then the housing is excessively large and the main line plug has to withstand too much torque. Consequently, the axial thickness or depth of the fan is also important, although less critical than the diameter in terms of fan flow rate. In this way, as indicated in the above, the depth of the fan should be between 1 and 5 cm. The housing of the apparatus preferably has between 5 and 15 cm from side to side of a face of the apparatus opposite the face of the apparatus adjacent to the main line plug in use. The distance between the opposite faces, ie the depth of the apparatus, is between 1 and 15 cm, preferably between 2 and 11 cm, more preferably between 3 and 8 cm. A larger appliance could not be supported by the main line power plug and in a double plug arrangement would interfere with the neighboring outlet, and a smaller appliance would not effectively clean the air. The motor may be of conventional construction but is preferably designed to operate continuously for an extended period. In addition, to filter the air by passing it through the treatment medium, for example the filter, the apparatus can be adapted to treat the air P1377 / 99 emitting component in the air. These components may include fragrances, odor neutralizing agents, aromatherapy oils, insect repellents or insecticides. These components can be included in the treatment medium or be emitted in the air in another way from or by the apparatus. For an improved understanding of the invention, a specific embodiment will now be described, with reference to the accompanying figures, in which: Figure 1 shows a front view of the air purification apparatus, in accordance with one embodiment of the invention. invention; Figure 2 shows a section along line A-A of the air purifying apparatus of Figure 1; Figure 3 shows the apparatus for air purification in a side view with the front cover open and the air filter removed; and Figure 4 shows a section along the line BB of Figure 2, facing away from the front view of Figure 1. Figure 1 shows a front view of an air purification apparatus representing an embodiment of the invention. A housing 1 having a width of about 8 cm and a height of about 14 cm is provided. The housing is made of ABS plastic. On the front of the P1377 / 99 housing 1 is provided with a sliding front cover 3 having air suction slits 5 and an observation hole 7. The air suction slits allow air to enter the apparatus. A purification means, in this embodiment a filter 33 (Figure 2), is mounted behind the cover. The observation hole 7 allows inspection of the filter, which can not easily be seen through the air suction slits 5, at least when the apparatus is in position on the socket near the floor. With reference to Figure 2, a fan 9 is provided in the housing 1. The fan 9 has blades 10 and a central cavity 11. An electric motor 13 is inside the central cavity 11 of the fan 9 to move the fan directly . The motor 13 is connected directly by means of the cables 17 to a transformer device 15, which is in turn connected by the cables 19 to the main line plug 21 having a live pin 23, a neutral pin 25 and a pin a ground 27. The arrangement of the bolts and the shape of the rear section of the housing is changed according to the local design of the main line plugs. For example, in Germany a design with two round bolts on a cylindrical plug would be used. The device has double insulation and thus the ground pin 27 only needs to be provided where required, for example, in the United Kingdom.

P1377 / 99 A filter holder compartment 31 is located in front of the fan 9 and cnicates with it by means of a hole or holes 41. A filter 33 is provided in the compartment 31. To increase the effective area of the filter surface in a small housing, the filter 33 is not flat. The filter is made from a piece of filter material 35 mounted on a grooved matrix 37, the grooved matrix 37 is made of a rigid plastic mesh with a perforation diameter of several millimeters. To obtain stability, a support matrix 39 made of a flat plate of the same material of the grooved matrix 37 is provided. The grooved matrix 37 is fixed to the support matrix 39 to achieve a rigid support for the filter. In the lower part of the filter there is an ear 40 to facilitate its removal. The filter material 35 is made of an electrostatic filter medium such as that sold by 3M. The electrostatic filter is able to trap particles with a size as small as 0.1 μm, even though the size of the mesh is much larger. The filtering material allows this because it is made of polypropylene which is charged with static electricity during its manufacture and which maintains said load. Any small particle that passes through the filter mesh therefore develops a dipole moment and is attracted to the mesh by the electrostatic charge and sticks to the mesh. In addition, P1377 / 99 particles can then be collected by the same part of the mesh, the filter only loses efficiency when so many particles have been trapped that the air flow through the mesh is restricted by the small size of the holes in the mesh. The front cover 3 slides between the closed position shown in Figure 2 and the open position shown in Figure 3. In the open position of the cover, the filter can be removed by pulling on the ear 40. A lock 43 is provided to maintain the front cover in closed position. The lock 43 can also be adapted to retain the front cover in its open position. In this embodiment, the lock 43 comprises a flexible plastic part 45 with a small indentation 47 at one end configured to mate with a protrusion 49 on the inside of the front cover. Figure 4 shows a view of the back of the fan in section. The arrow indicates the direction of movement of the fan 9 and shows the blades of inverse curvature 10 which curve in the opposite direction to the direction of movement of the fan. On the side, there is an opening 51 from which the filtered air emerges. To protect the fingers of the user and the blades of the fan 10, the outlet 51 can be shaped to have several slits 53 (Figure 3).

P1377 / 99 The fan of this mode has nine blades. The greater the number of blades, the lower the rotation speed that the fan must have to produce an effective air flow. A fan with twelve blades would also be effective. The motor is arranged to operate with a 6 volt direct current source through the transformer 15, the voltage must be carefully selected to provide the proper operating speed. The fan in this mode has an axial thickness (depth) of approximately 3 cm. This provides a sufficient flow of air with a low rotation speed of the fan, but is not so great that the housing becomes too thick to be held reliably by the plug. The housing has an internal transverse dimension of approximately 80 mm. The fan is approximately 68 mm. The space between the ends of the fan blades and the housing is not so small for excessive noise to occur and on the other hand, the fan is not so small that it has to be operated at high speed to produce an effective cleaning . In use, the electric motor 13 moves the fan to approximately 2500 rpm. This creates an appropriate area of low pressure behind the filter that makes it flow P1377 / 99 air inwards through the air intake slits 5 and then through the filter. When using an electrostatic filter, the effective air speed, the surface velocity through the filter has to be controlled precisely. If the superficial velocity is very large, the particles do not have time to be attracted to the filter mesh. On the other hand, if the air velocity is too low, the device will not be effective to clean the air even from a small room. The fan can be left connected to the electrical outlet and operate continuously. Over the course of several days or weeks the filter gradually collects more and more particles, and begins to block. When new, the filter is bright white. With use, it darkens or takes a dark shade of gray. The user can see that the filter has become dirty by looking through the observation hole 7, thus being able to change the filter when necessary. In alternative embodiments, the purification medium can be an adsorbent or adsorbent of gaseous materials instead of a filter. The absorbent or adsorbent can be activated carbon or calcium chloride. Such a purification medium can remove malodorous compounds from the domestic environment. The purification medium can also be configured to absorb automobile exhaust gases, such as ozone, nitrogen or sulfur oxides, bacteria P1377 / 99 in the air or virus. The apparatus may also be configured to emit components into the air, in addition to purifying the air.

P1377 / 99

Claims (10)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property; An air treatment apparatus adapted to be plugged directly into and supported by an electrical outlet, comprising: a purification means; a fan configured to produce an air flow through the purification means; an engine to operate the fan; accommodation; and a plurality of bolts attached to the housing and adapted to be inserted into the socket to supply the motor with electricity; wherein the fan includes a central cavity adapted to accommodate the motor in the cavity and to facilitate the support of the apparatus by means of an electrical plug; wherein the apparatus is sized to be supported only by the adjustment of the bolts within the electrical socket. 2. An apparatus for air treatment, according to claim 1, wherein the axial thickness of the fan is between 1 and 5 centimeters, of
2. P1377 / 99 preference of between 2 and 4 centimeters.
3. 3. An air treatment apparatus according to claim 1 or 2, wherein the motor is adapted, in use, to rotate the fan at less than 3000 revolutions per minute, preferably between 2000 and 2800 revolutions per minute.
4. 4. An air treatment apparatus according to claim 1, 2 or 3, comprising two, preferably three bolts attached to the housing and adapted to fit within the plug to supply the motor with electricity.
5. 5. An air treatment apparatus according to one of any of claims 1 to 4, wherein the purification means is an electrostatic filter preferably having a ribbed shape for increasing the effective surface area without increasing the linear size.
6. 6. An air treatment apparatus according to any one of claims 1 to 4, wherein the purification medium is an adsorbent or adsorbent of gaseous material, preferably selected from activated carbon or a molecular sieve.
7. 7. An apparatus for the treatment of air, according to one of any of claims 1 to 6, wherein the means for treating the air is removable.
8. 8. An apparatus for air treatment, P1377 / 99 according to one of any of claims 1 to 7, wherein the fan is a reverse curve driver, preferably having at least six blades, more preferably between 8 and 12 blades.
9. 9. An apparatus for treating the air, according to one of any of claims 1 to 8, wherein the housing is spaced apart from the radially outer ends of the fan blades with a gap of between 1 mm and 20 mm, preferably between 3 mm and 8 mm, and the housing is preferably sized to be between 5 cm and 15 cm transversely to one face of the apparatus opposite the adjacent face of the center line plug.
10. 10. An apparatus for air treatment, according to one of any of claims 1 to 9, which also includes a transformer to drive the engine located, in use, above the fan. P1377 / 99