HEARTH-FIRE SIMULATING APPARATUS

Abstract

 A hearth-fire simulating apparatus having a fire-bed simulation cover covering an internal space in its housing and having at least one open passage in the cover. In the housing a container bounding a nebulizing chamber for holding a liquid, an ultrasonic transducer having a transducing surface positioned in the container for generating mist above liquid in the container and a mist distributor bounding an elongated mist distributing chamber for distributing mist in longitudinal direction of the mist distributing chamber are arranged. The mist distributing chamber communicates with the nebulizing chamber via a mist passage above the container. An inlet of means for causing a flow of air through the mist-distributing chamber is located above the mist passage.

Description

FIELD AND BACKGROUND OF THE INVENTION

[0001] The invention relates to a hearth-fire simulating apparatus according to the introductory portion of claim 1.

[0002] Such an apparatus is known from EP2029941A1. While it is described in this document that the ultrasonic transducer generates a vapor, it is also described that the term "vapor" should be taken to refer to airborne liquid particles or droplets generated by the action of an ultrasonic transducer or the like on a liquid, and more especially to clouds or streams of such particles or droplets. Thus, what is actually generated by the ultrasonic transducer is in fact 'mist'.

SUMMARY OF THE INVENTION

[0003] It is an object of the present invention to provide a compact hearth-fire simulating apparatus that is more reliable and generates a realistic smoke effect, while emitting less humidity.

[0004] According to the invention, this object is achieved by providing a hearth-fire simulating apparatus according to claim 1. Because the inlet is located above the mist passage, it is located above the container, so that the risk of flooding the air flow drive means and spilling of water into the interior of the housing containing electric circuitry is avoided. Also after switching off of the apparatus, the exposure of the airflow drive means to humidity is reduced, because the airflow drive means are located relatively far away and above the area where mist is generated. Moreover, since mist is entrained from an area relatively far from the transducer where mist is generated, larger drops of mist, which tend to descend more quickly than fine drops, are sorted out of the mist before the mist is entrained by the airflow driven by the air flow drive means. Thus, a finer mist is emitted and larger drops that return to the container contribute less to humidifying the atmosphere in which the apparatus is operating.

[0005] The invention can also be embodied in a hearth-fire simulating apparatus according to claim 5. Because the mist distributing chamber communicates with the environment via a nozzle having a downstream end in or above the fire-bed simulation cover, the mist is not released in the interior of the housing, but at or beyond the at least one open passage in the fire-bed simulation cover. Thus, humidification of the interior of the housing by mist emitted therein is avoided. Furthermore, because the mist is injected into the upward flow of air at the openings in the fire-bed simulation cover, the mist is only exposed to evaporation in the upward airstream from the moment is becomes visible to the user, so no mist is lost in transit from under the fire-bed simulation cover due to evaporation before the mist appears from under the fire-bed simulation cover.

[0006] Particular elaborations and embodiments of the invention are set forth in the dependent claims.

[0007] Further features, effects and details of the invention appear from the detailed description and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] 

Fig. 1 is a schematic cross-sectional front view of an example of an apparatus according to the invention;

Fig. 2 is a cut-away perspective view of the apparatus shown in Fig. 1;

Fig. 3 is a schematic cross-sectional side view of the apparatus shown in Figs. 1 and 2; and

Fig. 4 is a schematic cross-sectional side view of another example of an apparatus according to the invention.

DETAILED DESCRIPTION

[0009] First, an example of a hearth-fire simulating apparatus 1 according to the invention shown in Figs. 1-3 is described.

[0010] The apparatus 1 has a housing 2f and a fire-bed simulation cover 3. The housing 2 and the cover 3 bound an internal space and the cover 3 has open passages 4. In the present example, the fire-bed simulation cover 3 has an appearance of an ember bed of an open fireplace in which wooden logs are burned. However, the fire-bed simulation may also simulate a fire-bed of other, more or less natural materials, including materials such as glass or stone, which do not burn in reality under circumstance occurring in a household fireplace. Also, the fire-bed simulation may consist of a single integral or composed member or include a plurality of loose items and instead of a plurality of openings 4, a single opening may be provided.

[0011] In the internal space bounded by the housing 2 and the cover 3, a container 5 bounding a nebulizing chamber 6 for holding a liquid 7, preferably water, is provided. An ultrasonic transducer 8 having a transducing surface 9 positioned in the container 5 so that it is immersed in the liquid 7 if the container 5 is filled up to a predetermined level 10. The transducer 8 is arranged for generating mist above the liquid 7 in the container 5 from particles of the liquid 7 in the container 5. Such ultrasonic transducers are well known in the art, in particular in the field of air-humidifiers. For replenishing liquid consumed in the course of generating mist, the container 5 communicates with a storage tank 11 via a filling pipe 12 of which a bottom end 13 co-operating with a floater valve 14 determines the level 10 to which liquid is replenished. If the level 10 is reached, the floater valve 14 presses against the bottom end 13 of the filling pipe 12 with sufficient force to prevent inflow of water. Depending on the level of water in the storage tank 11, the level of water 10 in the container 5 may vary slightly, but this does not compromise mist formation by the transducer 8.

[0012] A mist distributor 16 bounds an elongated mist distributing chamber 17 for distributing mist in longitudinal direction of the mist distributing chamber 17. The mist-distributing chamber 17 communicates with the nebulizing chamber 6 via a mist passage 18 above the container 5.

[0013] For driving a flow of air through the mist-distributing chamber 17, a ventilator 19 is provided. The ventilator 19 communicates with the mist-distributing chamber 17 via an inlet passage 20 into the mist-distributing chamber 17 located above the mist passage 18. Instead of a ventilator, also other means for driving a flow of air through the mist-distributing chamber may be provided, such as a pressure source containing pressurized air, an air pump or a venturi downstream of the chamber causing air to be drawn out of the mist-distributing chamber.

[0014] Light sources in the form of reflector lamps 21 emit upwardly directed light bundles for illuminating emitted mist via the openings 4. The fire-bed simulation cover may also include more or less transparent or translucent portions for allowing light to pass and rendering an impression of a glowing ember bed.

[0015] In the present example, the lamps 21 also constitute heat sources for driving an upward current of air out of the housing 2 through the open passages 4 in the fire-bed simulation cover 3. However, instead of or in addition to the lamps, for driving an upward current of air out of the housing, also other means may be provided, such as a further airflow drive means arranged for blowing air into the housing, which will then escape through openings in the fire-bed simulation cover, or a separate heat source under and/or in the opening(s) in the fire-bed simulation cover.

[0016] Because the means 19 for driving a flow of air through the mist distributing chamber 17 communicates with the mist distributing chamber via an inlet 20 into the mist distributing chamber 17 located above the mist passage 18, the risk of flooding the airflow drive means 19 is eliminated or at least substantially reduced and the risk of liquid spilling into the interior of the housing 2 is substantially reduced. Also after switching off of the apparatus, the exposure of the airflow drive means 19 to humidity is reduced, because the airflow drive means 19 are located relatively far away and above the area where mist is generated. Moreover, since mist is entrained by the airflow from an area relatively far from the transducer 8 where mist is generated, so that larger drops of mist, which tend to descend more quickly than fine drops, are sorted out of the mist before the mist is entrained by the airflow entraining the mist. Thus, a finer mist is emitted and larger drops returning to the container 5 contribute less to humidifying the atmosphere in which the apparatus 1 is operating.

[0017] The inlet 20 opens into a portion of the mist-distributing chamber 17 for directing the airflow along a path passing above the mist passage 18. Thus, mist is entrained from a portion of the mist distributing chamber 17 adjacent to the mist passage 18, where mist autonomously spreading out of the nebulizing chamber 6 is most dense, so that large amounts of mist can be entrained.

[0018] The inlet 20 has a bottom surface 22 sloping downwards into the mist-distributing chamber 17, so that any water that has entered the inlet passage 20 tends to flow back into the mist distribution chamber 17.

[0019] The mist distribution chamber 17 has a bottom surface continuously sloping towards the mist passage 18. Thus, water droplets that have accumulated against the wall and bottom surfaces of the mist distribution chamber 17 flow back to the mist passage 18 and subsequently flow through the mist passage 18 back into the container 5.

[0020] The mist distributing chamber 17 communicates with the environment via a nozzle 23 having downstream ends 24 partially in and partially above the fire-bed simulation cover 3. From the downstream ends 24, the mist is directly emitted into the environment, without flowing through the interior space of the housing 2. Thus exposure to humidity of parts in the interior of the housing 2 is substantially reduced, as is accordingly corrosion and the risk of malfunction due to corrosion. Also, keeping away humidity from electric circuitry inside the housing contributes to electric safety of the apparatus according to the invention. Furthermore, because the mist is injected into the upward flow of air at the openings 4 in the fire-bed simulation cover 3, the mist is only exposed to evaporation in the upward airstream from the moment it becomes visible to the user, so less mist is lost in transit from under the fire-bed simulation cover 3 due to evaporation before the mist appears from under the fire-bed simulation cover 3.

[0021] The apparatus 1 is further equipped with a screen 25 attached to and above a downstream end portion of the nozzle 23. The screen 25 reduces, and preferably practically eliminates, visibility of the downstream end of the nozzle 23. The screen 25 is permeable for mist emitted from the downstream end of the nozzle 23. The screen 25 conceals at least the nozzle 23 and preferably also other internals within the housing 2 from view, while allowing the mist to pass through the screen 25. Thus, the simulated smoke virtually appears to come out of the simulated burning material, as it rises out of smoldering wood in a real fire, which contributes to a very realistic impression.

[0022] The screen 25 may for instance be of foam or fibrous material or a combination of such materials. The screen is preferably relatively thin, e.g. less than 1, 2 or 3 mm to avoid clinging of droplets to the screen.

[0023] The screen has a pattern of passages through the screen, which passages are preferably quite small, e.g. formed by mutually communicating (e.g. generally spherical) cavities having a diameter of less than 7 mm, preferably less than 5 mm. Thus, individual passages are not easily visible from some distance. The pattern may me random or a regular distribution in accordance with a structure (e.g. rows and columns).

[0024] At least some of the passages in the screen 25 have an open cross-section oriented for allowing light from at least one of the light sources 21 to pass through the passage. This causes light from the light sources 21 to shine through the screen 25, causing the screen 25 to resemble a glowing piece of burnt wood, which further contributes to conveying a realistic simulation of a natural wood-fire. The light shining through the screen 25 also illuminates the mist, so that it is visible particularly well and resembles flames. The mist above the fire-bed simulation cover 3 may further be illuminated by light passing through translucent portions of the fire-bed simulation cover 3.

[0025] The passages having an open cross-section facing the light source or at least one of the light sources preferably have a projected free cross-sectional area for a collimated beam having a maximum cross-sectional size smaller than 4 mm and more preferably smaller than 3 mm, so that visibility of items behind the screen 25 through the openings in the screen 25 is very limited or avoided and the resemblance to natural smoldering wood is further enhanced.

[0026] The screen 25 has an upwardly facing surface that is predominantly black or dark grey, e.g. reflecting less than 60, 75 or 90% of visible light. Thus the screen shields the lighting from below from view and forms a dark background against which the impression of glowing materials and flames is particularly realistic.

[0027] Furthermore, a heating element 26 is provided in the screen 25. The heating element may for instance be an electric resistor through which an electric current, preferably of a controlled magnitude, is fed. The heater heats air in the screen 25 and causes the air to rise, entraining air from below the screen 25 and mist injected from the downstream end of the nozzle 23. This causes the mist, which has a tendency to descend, to rise quickly from the fire-bed simulation cover 3, in a manner similar to the rising of smoke from a natural fire. The heating element may also be arranged closely below the screen, for instance in the nozzle or integrated in a wall of the nozzle, so that air is heated closely below the screen. The heating element 26 is located above a level 3 cm, preferably 2 cm and more preferably 1 cm below the screen 25, so that it is located close to the screen. Since the heating element 26 heats the air closely below the screen 25 and accordingly closely below the air and mist exits only, little of the heat is distributed inside the housing, so the apparatus remains relatively cool and evaporation of liquid from inside the apparatus is reduced. For keeping the interior of the housing 2 cool, the light sources 21 are preferably of a type consuming very little power that is converged into heat, such as LED lamps.

[0028] For effectively causing mist to rise from the fire-bed simulation cover 3, the heating element 26 or heating elements for a 40 cm wide hearth-fire simulating apparatus preferably have a combined power of at least 50 W and more preferably at least 70 W. To avoid excessive heating of the screen, the power of the heating element 26 or heating elements is preferably less than 150 W and more preferably less than 120 W. For wider and smaller hearth-fire simulating apparatus, the wattage of the heating element is preferably proportionally larger or, respectively, smaller.

[0029] To effectively conceal both the nozzle 23 and the interior of the screen 25 from view, as in the present example, preferably the screen 25 extends across the openings 4.

[0030] The downstream ends 24 are located on one side of the open passages 4 in the fire-bed simulation cover 3, so that the nozzle 23 does not interfere with upward air current through the passages 4.

[0031] The downstream end 24 is formed by an opening facing in a direction from the side of the passages 4 in the fire-bed simulation cover 3 where it is located towards an opposite side of the passages 4 in the fire-bed simulation cover 3. Thus, the mist emitted from the downstream ends 24 is injected directly into the upward current of air driven out of the housing 2 via the passage 4, which is particularly advantageous for conveying a particularly naturally looking flame effect to the user.

[0032] For refilling the storage tank 11, a tank 27 is provided of which a filling spout 28 is arranged for removable placement in a filling opening 29 of the storage tank 11, that projects to the outside of the apparatus 1. Thus, the storage tank 11 can be refilled quickly and easily without spilling and without opening or removing parts of the housing 2 or the fire-bed simulation cover 3. The filling tank preferably has an internal volume identical to or slightly smaller than the internal volume of the storage tank 11, so that it can be filled in a single filling operation.

[0033] In Fig. 4 a further example of an apparatus according to the invention is shown in which the airflow drive means and the inlet of the means for causing a flow of air through the mist-distributing chamber are provided in the form of a heat source 69 emitting heat into the nozzle 73 and inlets 70 into the mist distributing chamber 67. The inlets 70 preferably communicate directly with the outside of the apparatus, so that a draft (chimney effect) caused by the heat source 69 emitting heat into the nozzle 73 effectively drives the air flow through the mist distributing chamber 67 and the nozzle 73. For generating a draft having a relatively strong upward power as a result of the heating of the air in the nozzle 73, a lower part of the nozzle 73 is relatively wide, preferably having an internal horizontal cross-sectional area of at least 40% and more preferably at least 50% or 60% of the largest horizontal cross-sectional area of the mist distributing chamber 67. In the present example, the inlets 70 are arranged in a lower half of the mist distributing chamber. However, the inlet or all or some of the inlets may also be arranged higher up, for instance just below the heat source 69 or at a level completely or partially in or above the height range over which the heat source extends.

[0034] For effectively driving airflow through the housing and through the nozzle, the heat source for a 40 cm wide hearth-fire simulating apparatus preferably has a power of at least 50 W and more preferably at least 70 W. To avoid excessive heating, the power of the heat source is preferably less than 150 W and more preferably less than 120 W. For wider and smaller hearth-fire simulating apparatus, the wattage of the heat source is preferably proportionally larger or, respectively, smaller. Instead of a single heat source, a plurality of heat sources each providing a share of the heating power may be provided.

[0035] The heat source 69 also constitutes the means for driving an upward current of air out of the housing 52 of the apparatus 51, through the open passages 54 in the fire-bed simulation cover 53. To this end, the heat source 69 emits heat into the internal space bounded by the housing 52 and the cover 53, so that also through this space an upward draft is generated. For replacing air flowing out of the openings 54, the housing 52 is provided with inlets 78. For enhancing the draft through the housing 52, in this example the inlets 78 are provided in a bottom 79 of the housing 52, which housing 52 is mounted on feet 80 so that it is raised from the floor 81. Thus, it is also ensured that the inlets 78 are not blocked if the housing 52 is positioned against a vertical surface, such as a wall of surrounds of a hearth.

[0036] In this example, the light sources 71 may be of a type consuming little energy and thus emitting little heat when in operation, such as LED lamps.

Claims

1. A hearth-fire simulating apparatus comprising:

a housing;

a fire-bed simulation cover, said housing and said cover bounding an internal space and said cover having at least one open passage; and, in said internal space:

a container bounding a nebulizing chamber for holding a liquid;

an ultrasonic transducer having a transducing surface positioned in the container so that it is immersed in the liquid if the container is filled up to a predetermined level, the transducer being arranged for generating mist above the liquid in the container from particles of the liquid in the container;

a mist distributor bounding an elongated mist distributing chamber for distributing mist in longitudinal direction of said mist distributing chamber, said mist distributing chamber communicating with said nebulizing chamber via a mist passage above said container;

a means for causing a flow of air through the mist-distributing chamber including an airflow drive means and an inlet;

a light source; and

means for driving an upward current of air out of the housing through the at least one open passage in the fire-bed simulation cover;

characterized in that the inlet of the means for causing a flow of air through the mist-distributing chamber is located above the mist passage.

2. An apparatus according to claim 1, wherein the inlet opens into a portion of the mist distributing chamber for directing air along an airflow path passing above the mist passage.

3. An apparatus according to claim 1 or 2, wherein the inlet has a bottom surface sloping downwards into the mist-distributing chamber.

4. An apparatus according to any of the preceding claims, wherein the mist distribution chamber has a bottom surface continuously sloping towards the mist passage.

5. A hearth-fire simulating apparatus comprising:

a housing;

a fire-bed simulation cover, said housing and said cover bounding an internal space and said cover having at least one open passage; and, in said internal space:

a container bounding a nebulizing chamber for holding a liquid;

an ultrasonic transducer having a transducing surface positioned in the container so that it is immersed in the liquid if the container is filled up to a predetermined level, the transducer being arranged for generating mist above the liquid in the container from particles of the liquid in the container;

a mist distributor bounding an elongated mist distributing chamber for distributing mist in longitudinal direction of said mist distributing chamber, said mist distributing chamber communicating with said nebulizing chamber via a mist passage above said container;

means for causing a flow of air through the mist-distributing chamber;

a light source; and

means for driving an upward current of air out of the housing through the at least one open passage in the fire-bed simulation cover;

characterized in that the mist-distributing chamber communicates with the environment via a nozzle having a downstream end in or above the fire-bed simulation cover.

6. An apparatus according to claim 5, further comprising a screen extending above at least a downstream end of the nozzle, the screen reducing visibility of the downstream end of the nozzle and being permeable for mist emitted from the downstream end of the nozzle.

7. An apparatus according to claim 6, wherein the screen is of foam and/or fibrous material.

8. An apparatus according to claim 6 or 7, wherein the screen has a pattern of passages, at least some of the passages having an open cross-section facing the light source or at least one of the light sources, for allowing light from the light source to pass through the opening.

9. An apparatus according to claim 8, wherein each of said passages having an open cross-section facing the light source or at least one of the light sources has a projected free cross-sectional area for a collimated beam having a maximum cross-sectional size smaller than 4 mm and more preferably smaller than 3 mm.

10. An apparatus according to any of the claims 6-9, wherein the screen has an upwardly facing surface that is predominantly black or dark grey.

11. An apparatus according to any of the claims 5-10, further comprising a heating element at least closely below or in the screen.

12. An apparatus according to claim 11, wherein the heating element is located above a level 3 cm, preferably 2 cm and more preferably 1 cm below the screen.

13. An apparatus according to any of the claims 5-10, wherein the heating element has a power consumption of 50 - 150 W.

14. An apparatus according to any of the claims 5-13, wherein the screen extends across the at least one opening.

15. An apparatus according to any of the claims 5-14, wherein the downstream end is located on one side of said at least one open passage in the fire-bed simulation cover.

16. An apparatus according to claim 15, wherein the downstream end opens in a direction from the side of said at least one open passage in the fire-bed simulation cover where it is located towards an opposite side of said at least one open passage in the fire-bed simulation cover.

17. An apparatus according to any of the claims 1-4 and according to any of the claims 5-16.

Drawing