Fike, Nancy J. (Tucson, AZ)
Fike, Robert L. (Tucson, AZ)

05/396450

04/30/1974

09/12/1973

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96/121

131/238, 55/385.800, 55/385.600, 55/446, 454/49

A24F19/00; B01D50/00; B01D50/00

55/385,387,316,440,446,DIG.36,525,527 131/238,240,256,10.7 98/43,66R,115K,115VM,DIG.7,43R,43A,43PS,66A

3049399	Composition and method for deodorizing air	August 1962	Gramson et al.
3303839	Ventilated cooking stove unit	February 1967	Tavan
3313309	Wet filter-containing smoker's appliance	April 1967	Wang
3461880	FILTER CIGARETTE	August 1969	Stubblefield
3516232	ASH TRAY DEVICE	June 1970	Gilbertson
3648837	AUTOMOBILE ENGINE POWERED, LITTER EVACUATING DEVICE	March 1972	Ogle

Lutter, Frank W.

Gifford, Vincent

Park, Jack H.

This application is a continuation-in-part of pending application Ser. No. 233,986 filed Mar. 13, 1972 and now abandoned.

We claim

1. An air purifying device for use in combination with an ash tray containing a lighted cigarette comprising:

2. The apparatus of claim 1 wherein the mechanical filter is comprised of glass fiber.

3. The apparatus of claim 1 wherein the mechanical filter is comprised of metal fiber.

4. The apparatus of claim 1 wherein the mechanical filter is comprised of reticulated plastic foam.

5. The apparatus of claim 1 wherein the adsorbent material is activated carbon.

6. The apparatus of claim 1 wherein the adsorbent material is activated alumina impregnated with potassium permangenate.

7. The apparatus of claim 1 wherein the horizontal dimension of the exit nozzle is greater than the vertical dimension thereof.

8. The apparatus of claim 1 wherein additional exit slots are provided along at least one side of the ash tray to form additional moving air curtains on the sides thereof.

9. The apparatus of claim 1 further comprising a quantity of air freshener in the flow channel.

10. A device as recited in claim 1 wherein the gas adsorbent filter means and the mechanical filter means are formed into a one piece removable element having a non-permeable outer shell with the gas adsorbent filter means located inside so that smoke may be drawn through the mechanical filter means and the gas adsorbent filter means and then exhausted through the exit nozzle.

BACKGROUND OF THE INVENTION

Broadly this invention relates to an air purifying device. More particularly this invention relates to an air purifying device for use with an ash tray for the purpose of drawing air and smoke rising from a lighted cigarette or cigar temporarily placed in the ash tray and forcing said smoke through a filtering means to remove the objectionable particulate matter and odor causing gas and vapor contained in the tobacco smoke.

While the apparatuses of this invention are applicable for many purposes, it is illustratively disclosed and described as applied to removal or reduction in concentrations of objectionable odor causing gas and vapors, and of particulate matter present in smoke rising from a cigarette temporarily placed in an ash tray.

DESCRIPTION OF THE PRIOR ART

Many persons, especially those who do not smoke cigars or cigarettes, find the odor of cigars or cigarettes to be very unpleasant. The particulate matter present in the smoke is also quite objectionable because it settles on table tops and other surfaces, is very prone to stain fabrics in drapes and the like, and is generally a problem to good housekeeping. It is also very objectionable in a small enclosed space such as an automobile.

In recent years, increasing amounts of evidence have tended to show that certain illnesses are related to cigarette smoking. While the principal thrust of these reports is directed toward the dangers to the smoker, it has been proven that breathing cigarette smoke from cigarettes smoked by another person in the same room or vehicle, is dangerous to non-smokers present in the same room or vehicle. Cigarette smoking is especially irritating to persons who have sinus conditions, allergies and other respiratory diseases.

Many persons while smoking cigarettes have the tendency to leave the lighted cigarette lying in the ash tray for a large portion of the time that the cigarette is burning. Smoke from the lighted cigarette lying in the ash tray rises and mixes with the air in the room or vehicle, causing discomfort to other persons, especially non-smokers present. While there are in existence air filtration devices for filtering all of the air in a room or in an entire building, these devices are not always satisfactory. A certain amount of time necessarily elapses before the cigarette smoke can be drawn through the filtering device, during which time persons present in the room or vehicle will experience the discomfort associated with exposure to offensive odor and distasteful particulate matter present in smoke. Some of the objectionable material will be adsorbed by furnishings in the room and a portion of the particulate matter will settle on walls, floors and furnishings before the smoke will have had time to arrive at and pass through and be filtered by the building filtering device. Also, these building and room filtering devices are quite large and expensive. Air exhaust devices are likewise provided in some vehicles and buildings, but these are not entirely satisfactory because of the same time lag as is described above, and also because they tend to interfere with the proper functioning and effectiveness of air conditioning and heating equipment.

There has been some recognition of this problem and devices have been proposed in the prior art to overcome it. In U.S. Pat. No. 2,029,192 a smoking stand is described which provides a fan and filtering element below an air permeable ash tray. Since cigarette smoke tends to rise, the fan must be quite powerful in order to overcome this natural tendency for smoke to rise; thus the device must be quite bulky, expensive and will be noisy. Moreover, a considerable part of the rising smoke will escape this reverse draft, and will therefore rise into the room without having gone through the filter. In addition, the ash tray must be a specially constructed type to permit smoke to be pulled down through it. There is also danger of larger ash particles falling through the openings in the ash receiver, which will fall on the fan and electric motor located below. Contamination of the motor and other precision mechanical parts by ash particles leads to premature failure.

In U.S. Pat. No. 2,747,101 there is disclosed a smoke disseminating ash tray having an electrically powered fan located below an ash receiver, with provisions for drawing smoke from a lighted cigarette placed in the ash receiver and forcing it through a helical chamber wherein it is exposed to a lamp capable of producing ultra-violet rays within the germicidal band, whereby the smoke is sterilized before being discharged back into the room. While this device may effectively sterilize a portion of the smoke, the ultra-violet lamp cannot remove the offensive particulate matter present in cigarette smoke or odor causing gases also present in smoke. Moreover, since the fan and irradiation chamber are located below the ash receiver, much of the smoke escapes the filter. Also, the fan must be sufficiently large to cause smoke to flow downward, in opposition to the normal tendency for smoke to rise.

In U.S. Pat. No. 2,788,085 there is described an ash tray with filter means located below an upwardly opening ash receiver containing a plurality of peripheral vents in the upper portion thereof and openings in the lower portions for passage of ashes into another container located therebelow. The fan draws smoke through the vents and through the lower openings to pass through a filter also located in the lower portion of the assembly. As in previous devices, the fan must draw the smoke downward, in opposition to the natural upward movement of smoke, and so the fan must be fairly large, making the fan and motor relatively expensive and noisy. Moreover, there is considerable likelihood that a portion of the smoke will still escape the downward draft of the fan, rising into the room to the irritation of any occupants thereof.

In U.S. Pat. No. 3,516,232 there is disclosed an ash tray device having a filter device inlet positioned directly above the ash tray, so smoke rising from the ash tray is drawn thereinto and through a filter element contained in the filter device. While this design avoids the problem of smoke rising and escaping past a side-or-bottom-located filter inlet, it is not entirely satisfactory for several reasons. The presence of a filter assembly or hooded inlet to a filter assembly immediately above an ash tray interferes with the use of the ash tray. Also, the power required to draw smoke through a filter element is considerable, requiring a fairly large electric motor and power consumption being in the range of 20 watts or more. Such large power requirements are too excessive for satisfactory battery operation, and so an A.C. cord would be required. Furthermore, the high power requirements result in a large, heavy, noisy unit. Furthermore, a portion of the smoke still escapes the filter into the room.

SUMMARY OF THE INVENTION

In an illustrative embodiment of our invention, as assembly is provided consisting of a housing having a central portion for holding an ash tray, and a smoke accumulating means located laterally and adjacent to the ash tray, with the entrance opening to the smoke accumulating means slightly higher than the top of the upwardly opening ash tray. Smoke and air enter the smoke accumulating means and pass into a filter means connected to the smoke accumulating means. An electric fan located in the smoke accumulating means draws smoke into the smoke accumulating means and forces it through the filter means. The discharge from the filter means is via an exit nozzle assembly located on the opposite side of ash tray from the smoke accumulating means and aimed at the entrance to the smoke accumulating means, to form a moving air curtain above the ash tray. The moving air curtain functions as a dynamic barrier to force the smoke rising from a cigarette in the ash tray below to enter the smoke accumulating means. The filter means contains a mechanical filter capable of removing at least a portion of the particulate matter from the smoke and an adsorbent material capable of adsorbing at least a portion of the gas and vapor present in the cigarette smoke. An air freshener may be incorporated in the filter element. The mechanical filter may be constructed of glass fiber or metal fiber. The adsorbent material is comprised of activated carbon or activated alumina impregnated with potassium permangenate and is formed into a shape having a central flow passage with the adsorbent material forming the inner linings thereof so a large surface area of the adsorbent material is exposed to the smoke.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of an air purifying apparatus including a separate ash tray in position.

FIG. 2 is a cross sectional view of the air purifying device of FIG. 1.

FIG. 3 is a cross sectional view of an air purifying device adapted for installation in the dashboard of an automobile.

FIG. 4 is a view with partial cross section details of a disposable filter element.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

I. the Apparatus

Referring to the drawings, there is illustrated in FIG. 1 an air purifying apparatus comprising a housing 1 including a flat portion 2 provided for placing an ash tray 3 thereon. Smoke accumulating means 4 includes an opening 5 immediately laterally adjacent to the ash tray 3.

Referring to FIG. 2, which is a cross sectional view of the device of FIG. 1, there is shown a fan 6 rotated by electric motor 7, both located within the smoke accumulating means 4. The electric motor 7 is operated by conventional A.C. house voltage supplied by an ordinary power cord (not shown), or it can be operated by a battery. Immediately below and in communication with the smoke accumulating means is a filter chamber having a filter element assembly 10 having an inner flow passage 8. The device is provided with an opening 9 to permit insertion of the filter element assembly 10. Filter element assembly 10 includes a flow through mechanical filter 11 to remove particulate matter from smoke being passed therethrough, which may be formed of glass fibers or other effective materials which are described fully hereinafter in this specification. Also included in the filter element assembly 10 is a surface area adsorbent filter 12, over which the smoke is passed. Odor causing gas and vapor normally present in tobacco smoke are adsorbed by the adsorbent material 12, the composition of which is described more fully later in the detailed description of the filter. Smoke continues to pass through the flow passage 8 of the filter element assembly 10. The adsorbent material may be formed into relatively flat, essentially parallel surfaces, or preferably, the material may be formed into a body having protrusions 13 which induce mixing in the smoke stream to improve contact between the smoke and the surface of the adsorbent material. An exit nozzle directs the smoke in the general direction of the entrance opening 5 of the smoke accumulating means. The shape of the nozzle is generally rectangular, having a horizontal dimension greater than the vertical dimension. The purpose of the exit nozzle shape is to form a moving curtain of filtered air 15 immediately above the ash tray. As smoke rises from the ash tray, it encounters the moving curtain of filtered air 15 which forms a dynamic barrier, preventing the smoke from rising into the room. The barrier also creates a low pressure zone to help draw smoke into the smoke accumulating means. Without this barrier of moving air immediately above the ash tray, only a portion of the smoke rising from a lighted cigarette in the ash tray would enter the smoke accumulating means, with the balance of the smoke escaping into the room.

In operating the apparatus of FIG. 2, a cigarette is placed in the ash tray 3 which is in position in the space 2 provided therefor in the apparatus. The power cord (not shown) is plugged into an electric outlet, the switch (not shown) is turned on and the electric motor 7 is energized. Fan blades 6 are rotated by the electric motor, drawing smoke from the cigarette into the smoke accumulating means through opening 5 provided therefor. The smoke passes through the filter means and is discharged through nozzle 14, forming the dynamic barrier 15. Dynamic barrier 15 forces essentially all of the smoke rising from the cigarette into entrance 5 of the smoke accumulating means 4 for filtration, with no discernable amount of the smoke passing into the room.

In a test model of this particular embodiment, there was no visible smoke or detectable odor in a small room after several cigarettes had been allowed to burn completely in an ash tray.

The apparatus illustrated in FIGS. 1 and 2 are of the type intended to be used on a table or other convenient support in a house, office or other building; however, the device can be adapted for installation in an automobile or other vehicle. FIG. 3 illustrates an air purifying device installed in a sliding mounting in the dashboard of an automobile or other vehicle. The apparatus is attached to runners 16 which slide into spaces provided therefor in the opening 17 of dashboard 18. The apparatus is shown in extended position, ready for use by a smoker in the vehicle. The end plate 19 follows the contours of the dashboard, and when the apparatus is pushed back into the dashboard when it is not in use, a relatively clean appearance is presented. As in the device of FIGS. 1 and 2, the smoke from a cigarette placed in the ash receptacle 20 rises and is drawn into opening 5 in smoke accumulating means 4 by fan 6, which is rotated by electric motor 7. In this embodiment of our invention, the motor 7 is energized by wires (not shown) which are attached to the electrical system of the vehicle in which the assembly is installed. Smoke is forced downward into the filter means 20 which includes a mechanical filter element 11. Particulate matter is removed from the smoke as it passes through the mechanical filter element 11. The smoke then passes along and contacts adsorbent material 12, which adsorbs and removes odor causing vapors and gases from the tobacco smoke. An air freshener (not shown) may also be present in the filter assembly to aid in freshening the air in the room. The filtered air, having had the particulate matter and odor causing gases and smoke removed therefrom, is discharged through exit nozzle 14, which directs the discharged air above the ash tray and toward entrance 5 to the smoke accumulating means 4. This moving blanket of air again forms a dynamic barrier 15 to prevent the upward passage of smoke rising from a lighted cigarette placed in the ash tray, forcing and drawing the smoke into the smoke accumulating means.

The apparatus of FIG. 3 is shown installed in the dashboard of an automobile as it would be if the automobile manufacturer installed the device in the automobile at the time the automobile was manufactured. The device may also be built to attach below the dashboard (not shown) to facilitate its addition to an existing automobile without having to cut a hole in the dashboard. Such a device would be essentially identical to that shown in FIG. 3 except for the mounting hardware.

The most critical design features of our invention are that the exit opening nozzle be located on opposite sides of the ash tray from the entrance opening to the smoke accumulating means, and that the exit nozzle be aimed generally at the entrance to the smoke accumulating means, so filtered air is blown above the ash tray to form a moving curtain of air, which acts as a dynamic barrier to the upward flow of smoke from a cigarette placed in the ash tray. The cross sectional shape of this moving air curtain corresponds essentially to the shape of the exit nozzle 14. The width of the moving air curtain should be slightly greater than the diameter of the ash tray 3 to insure that some part of the moving air curtain will be immediately above the burning zone of a cigarette placed in the ash tray 3. This is necessary to prevent smoke rising from the cigarette from escaping past the moving air curtain and into the room or interior of the vehicle without having been purified by passing through the filtering means. In a slightly different embodiment, several extra long, slender air nozzles are provided along the sides of the ash receptacle to provide moving air curtains along the sides to insure that no smoke escapes past the upper air curtain. The side air streams should be smaller in air volumes and aimed slightly toward the filter inlet, to insure that any smoke entrained thereby will be forced into the filter inlet.

Ii. the Filter Elements

Tobacco smoke is an exceedingly complex mixture of organic compounds. Over twelve hundred different organic materials have been identified in cigarette smoke, according to "ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY," 2nd. Edition, Interscience Publishing Co., volume 20, page 516. The smoke may be thought of as having two main parts, a gas phase and particulate matter phase.

The particulate matter phase is known to contain over 254 different compounds having particles as small as 0.22 microns (0.00022 millimeters). It has been reported that a normal mainstream puff of tobacco smoke contains 5 × 10 ⁹ particles per milliliter.

The gas phase is made up primarily of conventional and relatively unobjectionable gases such as nitrogen, carbon dioxide, hydrogen, argon and methane. There are also very small concentrations of complex organic molecules present in tobacco smoke, and these materials account for much of the unpleasant odor. For example, one of the major sources of odor in tobacco smoke is acrolein. While the concentration of acrolein in tobacco smoke is extremely small, the olfactory threshold of acrolein is 210 parts per billion, or 0.0000021 percent by weight.

From the above discussion of facts it can be appreciated that there are two very different and extremely difficult problems in purifying air contaminated with tobacco smoke: (1) how to remove the very small concentrations of odor causing gases and vapors, and (2) how to remove the very fine particulate matter.

Removal of particulate matter present in tobacco smoke necessarily involves the use of a mechanical filter or an electrostatic precipitator type filter. The electrostatic or electrical precipitator filter, also known as a Cottrell electrical precipitator, makes use of very high electrical voltage to remove very fine particulate matter, which is difficult to remove by conventional filters. While this type of filter is quite effective for removing the ultra fine particulates, it is quite large and expensive. For this reason, the electrostatic precipitator is not recommended for use in the present invention. Fortunately, there are mechanical filters which will do a satisfactory job.

Mechanical filters may be dry or viscous. Dry filters are generally fabricated of very fine fibers of glass, cellulose or metal. Viscous filters can similarly be made of fine fibers of glass, plastic or metal, and in addition the fibers are coated with a viscous fluid such as mineral oil. The presence of this viscous fluid on the surface of the fibers improves the efficiency of the filter for collecting and holding small particles. Because lighted cigarettes, cigars and matches are likely to be placed in the ash tray immediately adjacent to the filter elements, the filter material should be fire resistant, such as metal or glass fiber.

Another excellent material for use as a mechanical filter to remove particulate matter from cigarette smoke is foamed plastic. The foamed plastic must be reticulated, or open celled, as compared to the closed cell foamed plastic used in insulation, since the foamed plastic must have adequate gas permeability to permit free passage of smoke and air therethrough. The plastic may be of foamed polyester urethane, polyether urethane, polystyrene, polyethylene or poly (vinyl chloride).

While it is known that removal of the ultra fine particulate matter from cigarette smoke by the use of mechanical filters is quite difficult, we have found that the most objectionable visible portion of the smoke can be almost totally removed by the use of a one-eighth inch or more layer of glass fiber or other well known mechanical filter materials.

Removal of odor causing gas and vapor from tobacco smoke can be accomplished quite effectively by the use of an adsorbent material such as activated carbon or any other material capable of adsorbing gas or vapor from smoke. Activated carbon, or activated charcoal, is one of the most effective adsorbents for gaseous materials. Activated carbon is available in powdered or granular form, usually made by carbonization and chemical activation. Activated carbon is available for use in aqueous environment or in gaseous environment, and it is essential that the gaseous environment type be used in the subject invention. Activated carbon is prepared from a variety of sources such as hardwood, coconut and other nut shells, bituminous coke, etc. The different sources produce activated carbon with varying characteristics and adsorption capacity. The adsorption capacity is known to be a function of the surface area per unit weight. The surface area of activated carbon varies from 500 to 1,600 square meters per gram, depending on the source material. In recent years, filter elements have become available in rigid shapes manufactured from plastic bonded activated carbon, which eliminates the need for mechanical holder elements, thereby greatly simplifying the use of activated carbon filters.

Several characteristics of activated carbon make this material especially suitable for use in this invention. In "Activated Carbon Odorant Removal from Air Quantified" by J. M. Chapham, T. J. Junker and G. S. Tobias, "ASHRAE TRANSACTIONS," Part II, it was reported that the adsorption capacity of activated carbon increased with the molecular size of the adsorbate (the contaminant being adsorbed). Thus the large complex organic molecules present in very small concentrations in tobacco smoke will be adsorbed effectively even in the presence of much larger concentrations of oxygen, water vapor, carbon dioxide and other small molecular size materials.

Even more important, the breakthrough time for activated carbon is related to the concentration of the adsorbate in the air, according to the ASHRAE reference cited above, although in a fairly complex way. It was reported that only five times as much air could be processed at a concentration of 1 part per million contaminant as at a concentration of 10 parts per million. This means twice as much odorant is adsorbed per unit weight of activated carbon at a contaminant concentration of 10 ppm as at a concentration of 1 ppm. The significance of this fact to our invention is simply that activated carbon will adsorb more odorant per unit weight of activated carbon from cigarette smoke when used in a forced stream of smoke, coerced into the filter by the moving air blanket where the odorant concentration is quite high, than when used in a room or building filter apparatus where the odorant concentration is quite low because of dilution with room air.

Another excellent material for use in the instant invention to remove odor causing materials from tobacco smoke is a relatively new material which adsorbs and oxidizes the odor causing material. The product, available commercially under the trade name Purafil (Reg. T.M. of Borg Warner Corp.), is composed of activated alumina (Al ₂ O ₃ ) impregnated with potassium permangenate (KMnO ₄ ). This material and its use is described fully in U.S. Pat. No. 3,049,399. This material is available in pellet form, and is most conventionally used in a layer of from one to two inches thickness, across the surface of which the smoke is forced by the electric fan described earlier herein. This material adsorbs odor causing materials present in cigarette smoke and oxidizes them to materials which do not cause odors. It appears to last considerably longer than activated carbon.

In an especially preferred embodiment of this invention, illustrated in FIG. 4, filter element 10 is supplied as a one piece composite filter element comprising a layer of mechanical filter material 11 such as glass fiber and several surfaces of odor adsorbing material 12 such as activated carbon or permangenate impregnated alumina, bonded together chemically to maintain a rigid shape. The bonded adsorbent remains permeable to gas passing along the surface, so this gas will be adsorbed by the adsorbent material. The outer shell 22 of the disposable filter element is fabricated of a non-permeable material such as plastic, metal or any other suitable material which is impermeable and has sufficient strength to support the filter material 11 and the adsorbent material 12. The size and shape of the filter element of FIG. 4 must correspond closely to the size and shape of opening 9 in the filtration device of FIGS. 1, 2 and 3. The mechanical filter 11 is located in the filter element in such a position as to be in line with the air flow from fan 6 when the filter element assembly is installed in the air purifying device of FIGS. 2 and 3, so smoke and air are forced through the mechanical filter and into the interior flow channel 8 of the filter element 4. Similarly, opening 23 of the filter element must line up with the flow passage 24 in the apparatus of FIG. 2 so that when the filter element is installed in the apparatus, filtered air flows out of opening 23 in the filter element into flow passage 24 of the apparatus of FIG. 2 and is discharged through exit nozzle 14 to blow across the top of the ash tray, forming the moving blanket of air 15 which acts as a dynamic barrier to prevent smoke from rising from a cigarette placed in the ash tray and escaping into the room or interior of the vehicle. The adsorbent material 12 may be molded into one or more essentially flat surfaces, or the material may be molded into a shape including protrusions 13 which act as baffles to increase the mixing of smoke as it passes through the filter element of FIG. 4. These protrusions of baffles 13 also increase the filter surface area exposed to the smoke, thereby increasing the adsorption efficiency.

The advantage resulting from a one piece disposable filter element such as is illustrated in FIG. 4 is the ease and convenience of changing filter and adsorbent materials when the filter is clogged. While other filters may be used in our invention, the filter element of FIG. 4 is the preferred embodiment.

The particular advantage resulting from use of a surface effect filter as compared to a pass-through type filter is a vastly reduced fan or blower power requirement. A 1/250th horsepower electric motor has been found to be quite sufficient in the instant invention. Power consumption was about 3 watts compared to 20 watts for a 2 inch thick activated charcoal pass-through filter.

While only three embodiments have been disclosed, it will be evident that various other embodiments are possible in the arrangement and construction of the disclosed air purifying device without departing from the scope of the invention, and it is accordingly desired to comprehend within the purview of this invention such modifications as may be considered to fall within the scope of the appended claims.