GB2445731A - Deodorisation apparatus - Google Patents

Abstract

An apparatus adapted to emit into a potentially malodorous atmosphere one of a plurality of volatile liquids 11,12, at least one of which liquids is a counteractant for an atmospheric malodorant, the device comprising an associated sensor for said malodorant and associated therewith a sensor 2 and emission means 7, 8 responsive to said sensor for emitting the counteractant into the atmosphere in response to a signal from the sensor, to an extent sufficient to counteract the malodorant. The device may contain two liquids, one a fragrance for air freshening, the other being a cigarette smoke counteractant. In operation, impeller 7 releases a constant fragrance at a pre-set speed. However, should the malodour rise to an undesirable level, this is detected by sensor 2, which communicates this to circuit 3, which in turn actuates impeller 8. This causes the malodour counteractant in reservoir 14 to be evaporated. When the level has fallen the impeller 8 is turned off.

Description

Device This invention relates to devices for disseminating a number of

volatile liquids into an atmosphere.

Apparatus for disseminating volatile liquids, such as fragrances, insecticides, disinfectants, anti-viral agents and malodour counteractants, are well known and many varieties are available. One of the most common types utilizes the conveyance of the liquid from a reservoir to the atmosphere by means of a porous transfer member, typically a wick. Other devices utilize liquid-loaded gels, piezoelectric nebulisers, liquids behind membranes, aerosol sprays and pumps. These are all simple, single liquid devices and they have found ready acceptance, particularly for use as air fresheners.

However, they are single liquid disseminators, and one of the problems with such devices as fragrance emitters is that users become "habituated", that is, they become used to the odour and cease to notice it any more. It thus becomes less effective. The only remedy hitherto has been to use a second such device with a different fragrance and to exchange them at intervals.

Another problem in the field of air freshness has been the counteracting of atmospheric pollutants, when these are malodorous. There exist devices that can detect both solid and gaseous pollutants and neutralize them by filtration and ionization. Such devices are complex, relatively large and generally expensive.

It has now been found that it is possible to provide in a single simple apparatus the functions of overcoming habituation and of counteracting malodorous atmospheric pollution. The invention therefore provides an apparatus adapted to emit into a potentially malodorous atmosphere one of a plurality of volatile liquids, at least one of which liquids is a counteractant for an atmospheric malodorant, the device comprising an associated sensor for said malodorant and associated therewith signalling means and emission means responsive to said signaling means for emitting the counteractant into the atmosphere in response to a signal from the signaling means, to an extent sufficient to counteract the malodorant.

The invention additionally provides a method of both fragrancing an atmosphere and counteracting an atmospheric malodour, comprising the detection of a malodour by a sensor and, in response to a signal from a signaling means associated with the detector, the automatic emission into the atmosphere of a counteractant to an extent sufficient to counteract the malodorant.

By "counteractant" is meant any action performed by the counteractant that reduces or eliminates the olfactory detection of the airborne substance causing the malodour. This can be achieved by any convenient method. For example, the counteractant may be a fragrance with an odour sufficiently strong to mask the malodour. While this may be an acceptable solution in some circumstances, it often means that a high quantity of the counteractant is needed and the odour of that counteractant may be too strong.

In a particular embodiment, a counteractant is a liquid that does something other than masking the malodour by being so strong as to override it. For example, it may involve a chemical reaction of the counteractant with the malodorant to give a substance with lower or no malodour. Naturally such a counteractant should be a substance that itself is not malodorous or that is in any way a hazardous substance. The same applies to the reaction product. Alternatively, the counteractant may be a material that preferentially is detected olfactorily, thus preventing the detection of the malodour. This requires less concentration in the atmosphere, and is thus not so overwhelming.

There are many kinds of such counteractants for various undesirable malodourants. For example, one of the more undesirable malodours at the present time is tobacco smoke.

Typical materials used to counteract tobacco smoke include zinc ricinoleate, triethylene glycol and blends of dodecanal/myrtenal and dodecanal/citral. These can be used with art-recognised solvents. In addition, there are a numerous proprietary materials for counteracting tobacco smoke.

The sensor is a component capable of detecting the concentration of liquid in the atmosphere and signalling when a desired concentration is attained, or when the concentration drops below that desired concentration. The stimulus to which a sensor responds is not narrowly critical and maybe chosen from any known to the art. For example, in the case of a fragrance in an air freshener, many fragrances utilise ethanol as a solvent. A sensor capable of detecting ethanol can thus be calibrated to recognise a desired concentration of ethanol in the atmosphere (corresponding to a desired concentration of fragrance in the atmosphere) and send an appropriate signal.

Typical sensors include (but are not limited to) metal oxide semiconductor (MOS) sensors, conducting polymer (CP) sensors, quartz crystal microbalance (QCM) sensors and plastic optical fibre (POF) sensors. Sensors operate either by the conductance properties of the sensor changing as the external material is deposited (as in the MOS & CP sensors), the frequency of vibration as the mass changes (as in the QCM sensor) or the optical properties which are measured with a separate photo-optical sensor (as in the POF sensors). It is recognized that other types of sensor could be used in this application.

The sensor may be permanently in operation, or it may function intermittently, for example, by switching on to test the atmosphere at desired intervals.

The signaling means may be any suitable means for representing the quantity of malodorous substance as a continuous signal proportional in size to the quantity and transmitting it. In many of the detectors hereinabove described, the ability to signal is inherent, but it is possible to use other types and include amplifiers and transmission means.

Transmission may be by electrical wires, or it may be wireless communication, for example, by means of radio or infra-red waves.

In a typical operation (but by no means the only means of operation), the sensor is pre-calibrated to a desired threshold. When the malodour concentration rises above this level, the sensor signals to the apparatus, which then begins to emit the counteractant. When the level falls below this level, the apparatus ceases to operate.

The emitting means may be any suitable means for emitting a counteractant into an atmosphere. A common type is by means of some kind of forced ventilation. This is typically a fan or blower, but it may also be, for example, an aerosol or a spray with associated pump or pressure actuation, or a piezo-electric nebuliser.

In the case of a fan or a blower, the liquid is supplied to the air current thus generated by any convenient means, typically by means of a porous liquid transfer member one end of which is in contact with a source of counteractant and the other end of which is exposed to the air stream from the fan or blower. Liquid moves along the transfer member and is evaporated from it. Any suitable transfer member may be used, for example, the porous wicks commonly used in simple air fresheners. These may be of plastics, fibrous materials, sintered ceramics and metals, or they may be stamped from flat, porous materials such as cardboard or porous plastics. The source may be a any desirable source, but is often a reservoir in the form of a container, which may be easily replaced or replenished.

In a particular embodiment of the invention, there is a multiplicity of liquids, not all of which are counteractants. For example, one liquid may be a fragrance and the other a counteractant, the fragrance providing a background freshness and the counteractant being emitted only on demand. Needless to say, there may be more than one fragrance and more than one counteractant. It is also possible to combine different kinds of emission in a single apparatus.

The devices of this invention may be easily made from materials and components readily available commercially. They are simple and effective in operation.

The invention is now further described with reference to the drawings, which depict particular embodiments of the invention by way of example only, and are not intended to be limiting in any way on the scope of the invention.

Figure 1 is a schematic vertical side-elevation cross-section of a device according to the invention.

Figure 2 is a schematic horizontal cross-section through the device of Figure 1 In the drawings, the device has a rigid housing I. Mounted on a surface of the housing 1 is a sensor 2. In this particular example, the sensor is a commercially-available TGS 800 sensor (ex Figaro Engineering Inc.), useful for general airborne contaminants, for example, cigarette smoke. However, suitable sensors for any other pollutants may be used. This sensor is linked to a circuit 3 which is powered by a battery 4. The circuit controls two electric motors 5, 6 located in separate compartments, These rotate corresponding impellers 7, 8, which direct air currents across respective wicks 9,10 which convey volatile liquids 11, 12 from corresponding reservoirs 13,14. Liquid 11 is a fragrance for air freshening and liquid 12 is a counteractant for cigarette smoke (a mixture of a 50:50 (wi.) dodecanal -myrtenal) blend (10% (wt)), fragrance (75%) and solvent (15%).

In operation, impeller 7 releases a constant fragrance at a pre-set speed. However, should the level of malodour rise to an undesirable level, this is detected by sensor 2, which communicates this to the circuit 3, which in turn actuates impeller 8. This causes the malodour counteractant in reservoir 14 to be evaporated and blown into the atmosphere.

The impeller 8 continues to function until the sensor 2 communicates to the circuit 3 that the level has fallen below the undesirable level, at which point the circuit stops the impeller 8.

Claims (2)

1. Claims: 1. An apparatus adapted to emit into a potentially malodorous

   atmosphere one of a plurality of volatile liquids, at least one of which liquids is a counteractant for an atmospheric malodorant, the device comprising an associated sensor for said malodorant and associated therewith signalling means and emission means responsive to said signaling means for emitting the counteractant into the atmosphere in response to a signal from the signaling means, to an extent sufficient to counteract the malodorant.
2. 2. A method of both fragrancing an atmosphere and counteracting an atmospheric malodour, comprising the detection of a malodour by a sensor and, in response to a signal from a signaling means associated with the detector, the automatic emission into the atmosphere of a counteractant to an extent sufficient to counteract the malodorant.