Foul air eliminator
A converter for transforming malodorous components of foul air comprises a porous layer having an oxidizing agent and an aqueous solution of a promoter. The promoter is preferably a water-soluble ethylene oxide or propylene oxide adduct. The layer is typically used in a gas-handling system to eliminate the foul air from a toilet or a bedpan. The layer can be used alone or with a second layer of activated charcoal A Lewis acid and/or a Lewis base can be also used with the converter.
This application is a continuation of U.S. application Ser. No. 10/065,537 filed Oct. 28, 2002, which is a continuation of U.S. application Ser. No. 09/661,109 filed Sep. 13, 2000, and claims the benefit of U.S. Provisional Application No. 60/153,764 filed Sep. 13, 1999.
BACKGROUND OF INVENTION1. Field of the Invention
This invention is a device for removing odors from air. Specifically, the present invention relates to air cleansing during the operation of a contemporary toilet to eliminate the unpleasant odors and adventitious bacteria. More particularly, the present invention concerns retrofitting the device onto existing toilets.
2. Description of the Related Art
Since the dawning of the modern age many people have at one time or another contemplated ways to cope with or eliminate malodorous air and ammonia that arises during use of the contemporary toilet. A number of methods have been employed for this purpose. These include burning candles, use of incense, opening windows, switching on overhead fans, spraying fragrances, use of elaborate toilet bowl designs and so on. These methods are ineffective, a nuisance to implement or too costly to install. Apart from the invention described herein, a single product, which is safe, effective and economical in dealing with this problem, has not emerged. Past solutions may have acted to ameliorate foul air to a limited degree, but they did so in a circuitous fashion—by rerouting the flatus or hiding it with fragrances and the like. Previous approaches do not target the fundamental cause of the trouble. The direct method of addressing this problem lies in the chemistry associated with the malodorous components themselves.
In contrast to fecal matter, tissue fluid, blood or other bio-fluids, the body of knowledge on the biochemical events giving rise to the formation of flatus is scant. Furthermore, there is not a single source that deals with the subject in a thorough fashion. Information on the compositional aspects of flatus taken from varied sources reveals the physiology and chemistry to be relatively plain. However, eliminating its negative properties affords a challenge. Flatus arises from aerophagia (swallowed boluses of air), gas diffusion (e.g. carbon dioxide) from the blood, bacterial production in the lumen, descending and sigmoid colons and from trace quantities of non-gaseous components carried with the flatus by mass transfer during expulsion. Swallowed air accounts for a large portion of nitrogen, oxygen and carbon dioxide, while diffusion from gas gradients contributes much of the remaining carbon dioxide and nitrogen portions. Methane, hydrogen, hydrogen sulfide (as well as a small amount of mercaptan) and carbon dioxide result from bacterial fermentation of residual ingesta at the point of the lumen and at locations further down in the alimentary tract. The trace non-gases are primarily heterocyclic amines from protein rich ingesta. Specifically, the two amino acids, proline and tryptophan can lead to pyrrole and indole (C4H5N and C8H7N respectively) derivatives subsequent to deamination/decarboxylation of the parent molecules. Nitrogen from deamination is nearly quantitatively converted to ammonia and later to urea in a formal condensation with carbon dioxide in vivo. Energy from that transformation is captured and stored in lipid form as ATP for later use in the body. The remaining moieties of the proline and tryptophan precursors are readily converted in vivo to pyrrole and indole nuclei respectively. Both of these materials are thermodynamically stable owing to their aromaticity, but this is especially germane in the case of indole and its derivatives, which are resistant to further catabolic breakdown. Its structural integrity and associated physical-chemical properties are preserved while in the body. Consequently, indole is believed to be more ubiquitous in flatus among the general population, and the only alkaloid of appreciable significance in flatus. Even so the majority of this non-gaseous component will be eliminated as-is in fecal matter rather than flatus. The only other relevant constituent in flatus is low molecular weight carboxylic acid (butyric acid for example) that is generated from enzyme hydrolysis of ester oils. Flatus components and their approximate relative abundance are depicted below.
It is to be noted that there is variation in flatus for individuals between expulsions as well as variation between individuals within the general population as a whole. For example, one third of the population produces no methane. This is why only ranges for flatus components are given.
The major components (Table 1) are present at a strength that is orders of magnitude greater than the minor ones (Table 2). The sum of all minor components in flatus seldom exceeds 1%. However, the most interesting aspect of flatus composition is that there is no major component which is malodorous—and there is no minor component which is not malodorous. Thus, as it is the principal intent of this invention to eliminate the experience of foul air exposure, it was only necessary to address problems created by the minor components (Table 2), and to a lesser extent, ammonia from urination. Indoles, pyrroles, carboxylic acids and most mercaptans are not gases at ambient or in vivo conditions. These four minor components, therefore, are susceptible to capture by activated charcoal. Indeed, in prior art, cited herein, a few previous inventors have incorporated the use of activated charcoal in their apparatuses. These devices were undoubtedly successful in removing these four substances, at least to a limited degree.
On the other hand activated charcoal cannot be used to mitigate hydrogen sulfide, contrary to numerous efforts and claims of the past. The mechanism for adsorption by activated charcoal involves, in sequence, condensation, Van der Walls attraction and capillary action to the interior core of the charcoal particle, at or near the boiling point of the intended substrate. With a boiling point of less than −60 C, hydrogen sulfide cannot undergo even the first step of the adsorption process unless it is taking place under cryogenic conditions.
As ambient conditions are not conducive to this adsorption process, it would be advantageous to devise an alternative method for removing hydrogen sulfide, within the operating parameters to be found in the user environment.
SUMMARY OF INVENTIONThe invention lies in a self-contained foul air eliminator comprising a housing having an intake port, an exhaust port, an impeller, and a converter. The converter includes an oxidizing agent or a hydro-sulfur labile compound in an amount sufficient to effectively react with malodorous compounds in air driven by the impeller from the intake port to the exhaust port through the converter. The converter further includes an aqueous solution of a promoter carried by a support in a position to accelerate the reaction between the oxidizing agent or hydro-sulfur labile compound and the malodorous compounds.
Preferably, the housing contains a power source such as a battery to render it portable. For example, it can be mounted to a toilet. A foul air eliminator according to the invention can also have the housing adapted to connect to a 120-volt household current to drive the impeller. Preferably, the impeller operates in a range of 20 SCFM to 150 SCFM. In another aspect, eliminator can have a fragrance repository between the converter and the exhaust port.
BRIEF DESCRIPTION OF DRAWINGSIn the drawings:
This invention includes two sub-units. The first sub-unit is referred to herein as the “converter” (or “converting system”). It is that part of the device, which contains the agents that chemically change ammonia from urination and odoriferous components in flatus to non-malodorous substances. The second sub-unit is referred to herein as the “gas-handler” (or “gas-handling system”). It delivers the foul air to the converter for alteration and discharges the malodor-free air that results. In addition, the two systems are integrated in a manner that introduces efficiency to the overall process.
1. Converter
Referring to
The area of the incident surface varies. For example, effective bathroom models have had areas of two to six square inches. The surface area can be larger in units that have more demand, such as a hospital unit (see
Hydrogen sulfide and, to a lesser extent, mercaptans, are the only odor-causers, other than ammonia from urination, that require chemical conversion. The other malodorous components can be dealt with in a manner well known in the art. The sulfur compounds are transformed into non-volatile and non-odorous compounds when they are reacted with various oxidizers. Therefore, in its simplest form the conversion chemical may consist only of an oxidizing agent—particularly if removing hydrogen sulfide is the only objective. This simplest approach does in fact have merit. The reason is that hydrogen sulfide is the most egregious of the malodorous components. It is toxic and detectable by the human olfactory system at extremely low levels (typically parts per billion). Moreover, current theory on nerve receptor site mechanics holds that both primary and secondary receptor nerves are capable of detecting multiple numbers of different substances, and that in order for a nuisance odor to be experienced, a certain threshold number of these sites must be triggered directly or indirectly. It may well be that for most of the population, simply eliminating the odor owing to the hydrogen sulfide could sufficiently reduce the total impact of the entire group of malodorous components, so that the nuisance threshold is not reached. This would mean a commercial goal of eradicating the unpleasant experience could be achieved by using only an oxidizing agent in this device in most instances. Thus, at a minimum, the converter fabric has a single oxidizing agent applied to it.
For daily use on a given commode over a three month period, the minimum quantity of oxidizing agent required for effective operation of this invention varies from 0.1 grams to 10 grams depending on the molecular weight, particle size and reactivity of the oxidizing agent used. The reason that such a small quantity of reagent is needed is that the amount of malodorous components being converted are so miniscule. Indeed, the longevity of the converter module depends more on the intramolecular degradation tendencies of the specific reagents being used than on the load level of the malodorous components during use.
In some instances the oxidizing agent must first be adsorbed on a support before impregnation on the fabric. In other cases it can be used neat—or on a support. A useful support can be any chemically resistant adsorbent material including, but not limited to, precipitated silica, fumed silica, diatomaceous earth, inert elastomeric pellets, vermiculite, natural or synthetic zeolites or alumina. Common oxidizing agents that are effective in this device are listed below (Table 3). Mixtures of these materials in different ratios are also effective.
In addition, there are numerous, more exotic agents that also effectively oxidize hydrogen sulfide (and mercaptans) in this device. These are indicated below (Table 4) and cross referenced with CAS numbers.
Yet a third type of material that can be reacted with hydro-sulfur compounds (hydrogen sulfide and mercaptans) can be referred to as “hydro-sulfur labile” compounds. These materials are organic substances possessing functional groups that can form products resulting form nucleophilic addition. For example, phthalic anhydride is effective at a level of one gram in a standard unit (see
Interestingly, in addition to being capable of reacting with certain sulfur compounds, some of the reagents listed act as disinfectants as well. In particular, sodium dichloroisocyanuric acid and sodium hypochlorite have been proven to be be effective for this purpose.
For a more effective version of this appliance the carboxylic acid and amine (indoles and pyrroles) portions of flatus needed to be addressed as well. Activated charcoal can theoretically capture these materials. But unfortunately, the adsorbed species can be desorbed if the temperature in the room where the device is located should rise for any reason. Thus, as implied earlier, any device solely employing activated charcoal will end up emitting odor after a certain period of use. To avoid this, the carboxylic acids and amines, including ammonia from urination, must also be chemically converted to non-volatile substances rather than merely adsorbed. Unlike in the case of hydrogen sulfide and mercaptans, neither oxidation nor nucleophilic addition can be used for this purpose. However, carboxylic acids can be converted to non-volatile salts with a Lewis base. Analogously, the amines can be made into salts with a Lewis acid. But because Lewis acids and bases are not compatible, only one or the other can be impregnated along with the sulfur compound converter (Tables 3, 4 and 5) on a single piece of converter fabric. Thus the need for separate agent-bearing zones. Thus, referring to
During the course of developing this device, two secrets were discovered that marginally improved the effectiveness of the converter. The first was that when aqueous solutions of certain materials pre-adsorbed on a support (such as silica or others—vide supra) were mixed with select chemical converting reagents prior to being applied to the converter fabric, the performance of the converter was boosted. These materials (Table 6), referred to herein as “promoters,” are linked by common features.
The promoters cited are all water-soluble ethylene oxide or propylene oxide oligomers. They have inverse cloud points owing to their propensity to complex with water. Since solvent-solute kinetics are intrinsically more favorable than gas-solid kinetics, the enhanced performance is undoubtedly due to the presence of the bound water. In short, any water-soluble ethylene oxide or propylene oxide derivative, or mixtures of such, will have this beneficial effect to some degree, depending on the identity of the converter agents it is blended with and the degree to which it is capable of binding with water.
The second thing learned related to the use of activated charcoal. Even though it is not especially effectual when used by itself, some performance synergy is realized when it is used to complement the actual converter chemicals. Activated charcoal is not compatible with oxidizing agents, so the two cannot be blended together. But when a zone of charcoal is positioned upstream, it acts as a sort of holding reservoir for foul air components, which can release malodorous components to the converter chemicals at a later point in time. This is important in instances when the converter would otherwise be swamped by a heavy flux of malodorous air. Therefore, referring to
The converter fabric itself can be formed out of nearly any flexible cloth or mat material—including fordriniered pulp, woven, semi-woven, natural fiber, synthetic fiber, high rag content paper or felt, which is at least somewhat resistant to chemical degradation and is of sufficient porousity to allow a minimum air flow rate of 0.1 SCFM. This is true for two reasons: 1) the converter chemicals used are generally not especially reactive or harsh. 2) Any destructive aptitude they possess is severely modulated by their relatively low concentration. For example, half-inch nylon fiber mat with nominal 25-micron pore size works as well as one inch polypropylene fiber mat with 100-micron pore size. The number and kinds of different fabric materials (or porous beads in the case of a packed column arrangement) that can be successfully employed in fabricating the converter appears to be limitless.
2. Gas Handler
Referring now to
Specifically, the gas-handler 400 includes an intake 402, impeller 404, exhaust port 406, power source 408, and housing 410.
Housing 410 communicates between the intake 402 and the exhaust 406, carrying the impeller 404 and the converter 300, as depicted schematically (see
In order for the converter to function properly, a majority of the malodorous gas must first be collected. This is accomplished by means of intake 402, including a port 1 leading to a hollowed flange 2 mounted on the sides and/or back of the toilet bowl during installation (
It was learned that a large variety of impellers (fans, blowers and so on) were capable of efficiently delivering flow rates far in excess of 0.1 SCFM. Two-sided intake blowers were particularly attractive in experimental models owing to their shape. The impeller may be optionally activated by means of either a pressure sensitive actuator (set nominally for 20 pounds), or a manual control button. In either case the switch communicates with the power source and impeller (blower) through an electrical lead housed within the unit itself. In practice, impellers rated for around 20 SCFM were found to work well. The number of impellers commercially available that can deliver a flow rate in this neighborhood is staggering. Ones that have the following rating options all work satisfactorily in this invention:
The exhaust 406 is the opening by which the purified air escapes the handler 400 and reenters the room (
The relatively diminutive flow rate requirements make it possible for power source 408 to be either a battery or a wall outlet (120 volt or 240 volt). It is housed within the unit itself in the case of the former. Model work demonstrates that a 12 volt battery can operate for six to eight weeks with regular daily use of this device before replacement is needed. Thus, there is considerable leeway for selecting sources of power to be incorporated into this invention. Independent of the source of power, the switch mechanism that activates whatever power source is in place can be selected from a variety of options. Among them are:
Flatus, though unpleasant, is neither hazardous nor corrosive. And since, by design, the chemical reagents housed in the converter never make direct contact with the gas-handling system, materials of construction of the gas-handler is not a troublesome issue. The only requirements are that they be machinable, semi-rigid to hold shape and have enough longevity to be practical. Therefore, a large array of materials can be used in fabricating this invention—including, but not limited to, the following:
In addition, the flexibility engendered by the overall invention design affords the potential of manufacturing all or portions of the gas-handling system by injection, or blow molding methodologies.
Referring to
The housing 10 is PVC. The overall length is 5 inches. The width is approximately 5.5 inches at its widest point. The battery is located near the bottom on the interior of the unit and is secured with adhesive and a truncated PVC flange just large enough to hold it. The flange extends laterally toward the center. It is positioned against one side so air flow is not obstructed. The unit sits up off the floor with a clearance 11 of approximately two inches. Its weight is supported by means of a hook-shaped fastener 12 that curves over and under the toilet bowl rim. The fastener 12 is an extension of the lower surface of the intake port. The exhaust port 13 is approximately six square inches and is fitted with a fragrance repository 14 composed of a scent absorbed onto a piece of porous felt that is roughly the same size as the exhaust port opening.
Turning now to the converter 15, the illustrated embodiment is the more advanced three-tiered version described earlier (
The second layer of the converter in this embodiment is another half-inch thick piece of fiber mat impregnated with 75 grams of the following formula:
The third layer is yet another half-inch thick mat that was impregnated with 25 grams of the following formula:
The top two layers rest on the bottom one, which is in turn supported by the PVC lip described earlier. This unit operated successfully for eight weeks before the battery required changing.
EXAMPLE 2 Referring again to
The housing 10 is PVC. The overall length is 15 inches. The width is approximately 5.5 inches at its widest point. The battery is located near the bottom on the interior of the unit and is secured with adhesive and a truncated PVC flange just large enough to hold it. The flange extends laterally toward the center. It is positioned against one side so air flow is not obstructed. The unit sits up off the floor with a clearance 11 of approximately two inches. Its weight is supported by means of a hook-shaped fastener 12 that curves over and under the toilet bowl rim. The fastener 12 is an extension of the lower surface of the intake port. The exhaust port 13 is approximately six square inches and is fitted with a fragrance repository 14 composed of a scent absorbed onto a piece of porous felt that is roughly the same size as the exhaust port opening.
An alternative converter 15 is the simple one-layer design of
The mat is half-inch thick polypropylene fiber impregnated with 50 grams of the following formula:
This unit operated with excellent success for a seven weeks.
EXAMPLE 3 Referring again to
The housing 10 is PVC. The overall length is 5 inches. The width is approximately 5.5 inches at its widest point. The battery is located near the bottom on the interior of the unit and is secured with adhesive and a truncated PVC flange just large enough to hold it. The flange extends laterally toward the center. It is positioned against one side so air flow is not obstructed. The unit sits up off the floor with a clearance 11 of approximately two inches. Its weight is supported by means of a hook-shaped fastener 12 that curves over and under the toilet bowl rim. The fastener 12 is an extension of the lower surface of the intake port. The exhaust port 13 is approximately six square inches and is fitted with a fragrance repository 14 composed of a scent absorbed onto a piece of porous felt that is roughly the same size as the exhaust port opening.
The third embodiment of the converter 15 is the two-tiered arrangement described earlier (
The second layer is another half-inch thick polypropylene mat that was been impregnated with 25 grams of the following formula:
This unit operated with excellent success for two and a half months.
EXAMPLE 4 In another model all parameters were identical with those described in the first example with the following exceptions:
In yet another model all parameters were identical with those described in the second example with the following exceptions:
In still another model all parameters were identical with those described in the first example with the following exceptions:
A “heavy duty” version 20 of the present invention is shown in
Another version of the present invention 30, shown in
Solving the chemistry is the precise approach which the present invention employs. Using a chemical converter, the malodorous components undergo a chemical metamorphosis to materials that are inoffensive to the sense of smell. Basically, it singles out the malodorous components and irreversibly captures and simultaneously converts these materials to substances that are not capable of being re-released into the air to generate the foul odor experience. Fortuitously, many of the materials, which work effectively as converters, also destroy bacteria. In addition, use of this invention obviates the need for using spray canisters, which can introduce CFCs (chlorofluorocarbons) that have been cited as having a potentially harmful effect on atmospheric ozone.
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.
Claims
1. A foul air converter comprising:
- a. a first porous support further comprising one or more promoters adsorbed thereon, and
- b. one or more oxidizing agents in an amount sufficient to effectively react with hydrogen sulfide or mercaptans in air passing through the converter,
- wherein the oxidizing agent is in contact with the promoter, and wherein the promoter is provided in an amount effective to accelerate the reaction between the oxidizing agent and the hydrogen sulfide or mercaptans
2. The converter of claim 1 wherein the one or more promoters comprise a surfactant having an inverse cloud point.
3. The converter of claim 3 wherein the surfactant comprises an ethylene-oxide oligomer or a propylene-oxide oligomer.
4. The converter of claim 3 wherein the surfactant has a single hydroxyl group.
5. The converter of claim 3 wherein the surfactant is non-ionic.
6. The converter of claim 1 further comprising a hydro-sulfur labile compound in an amount sufficient to effectively react with hydrogen sulfide or mercaptans in air passing through the converter.
7. The converter of claim 1 further comprising one or more Lewis acid compounds or one or more Lewis base compounds in contact with the promoter, wherein the Lewis acid or Lewis base compound is present in an amount sufficient to effectively react with malodorous compounds in air passing through the converter.
8. The converter of claim 7 further comprising:
- a. a second porous support comprising one or more promoters adsorbed thereon, and
- b. one or more Lewis acid compounds in an amount sufficient to effectively react with malodorous amines in air passing through the converter or one or more Lewis base compounds in an amount sufficient to effectively react with malodorous carboxylic acids in air passing through the converter,
- wherein the Lewis acid compound or Lewis base compound is in contact with the promoter and wherein the promoter is provided in an amount effective to accelerate the reaction between the Lewis acid compound or Lewis base compound and the malodorous carboxylic acids or amines.
9. The converter of claim 1 wherein the first porous layer is sufficiently porous to allow an air stream delivered by a gas handler to pass through the converter at a rate of 0.1 SCFM or higher.
10. The converter of claim 1 or 2, wherein the ratio of the weight of the one or more oxidizing agents to the weight of the one or more promoters is at least 1 to 178.5.
11. The converter of claim 11 wherein the ratio of the weight of the one or more oxidizing agents to the weight of the one or more promoters is at least 1 to 125.
12. The converter of claim 11 wherein the ratio of the weight of the one or more oxidizing agents to the weight of the one or more promoters is at least 1 to 1.785.
13. The converter of claim 11 wherein the ratio of the weight of the one or more oxidizing agents to the weight of the one or more promoters is at least 1 to 1.25.
14. The converter of claim 11 wherein the ratio of the weight of the one or more oxidizing agents to the weight of the one or more promoters is at least approximately 1:1.
15. A foul air converter comprising:
- a. a first porous support further comprising one or more promoters adsorbed thereon, and
- b. one or more hydro-sulfur labile compounds in an amount sufficient to effectively react with hydrogen sulfide or mercaptans in air passing through the converter,
- wherein the hydro-sulfur labile compound is in contact with the promoter, and wherein the promoter is provided in an amount effective to accelerate the reaction between the oxidizing agent and the hydrogen sulfide or mercaptans
16. The converter of claim 15 wherein the one or more promoters comprises a surfactant having an inverse cloud point.
17. The converter of claim 15 or 16 wherein the ratio of the weight of the one or more hydro-sulfur labile compounds to the weight of the one or more promoters is at least 1 to 17.85.
18. The converter of claim 15 or 16 wherein the ratio of the weight of the one or more hydro-sulfur labile compounds to the weight of the one or more promoters is at least 1 to 12.5.
19. A foul air converter comprising:
- a. a first porous support further comprising one or more promoters adsorbed thereon, and
- b. one or more Lewis base compounds in an amount sufficient to effectively react with malodorous carboxylic acids in air passing through the converter,
- wherein the Lewis base compound is in contact with the promoter, and wherein the promoter is provided in an amount effective to accelerate the reaction between the oxidizing agent and the malodorous carboxylic acids.
20. The converter of claim 19 wherein the one or more promoters is a surfactant having an inverse cloud point.
21. The converter of claim 19 or 20 wherein the ratio of the weight of the one or more Lewis base compounds to the weight of the one or more promoters is at least about 16:21.
22. The converter of claim 19 or 20 wherein the ratio of the weight of the one or more Lewis base compounds to the weight of the one or more promoters is at least approximately 1:1.
23. The converter of claim 19 or 20 further comprising:
- a. a second porous support comprising one or more promoters adsorbed thereon, and
- b. one or more Lewis acid compounds in an amount sufficient to effectively react with malodorous amines in air passing through the converter or one or more Lewis base compounds in an amount sufficient to effectively react with malodorous carboxylic acids in air passing through the converter,
- wherein the Lewis acid compound or Lewis base compound is in contact with the promoter and wherein the promoter is provided in an amount effective to accelerate the reaction between the Lewis acid compound or Lewis base compound and the malodorous carboxylic acids or amines.
24. A foul air converter comprising:
- a. a first porous support further comprising one or more promoters adsorbed thereon, and
- b. one or more Lewis acid compounds in an amount sufficient to effectively react with malodorous amines in air passing through the converter,
- wherein the Lewis acid compound is in contact with the promoter, and wherein the promoter is provided in an amount effective to accelerate the reaction between the oxidizing agent and the malodorous amines.
25. The converter of claim 23 wherein the ratio of the weight of the one or more Lewis acid compounds to the weight of the one or more promoters is at least about 2.25:1.
Type: Application
Filed: May 19, 2004
Publication Date: Jan 13, 2005
Inventor: Morey Osborn (Austin, TX)
Application Number: 10/848,948