DEVICE FOR HEATING AND/OR VAPORIZING A FLUID SUCH AS WATER

Abstract

A device for heating and/or vaporizing a fluid is provided. The device comprises a heat conductive inner conduit defining a fluid flow pathway. An electrically powered heating element is arranged to surround said inner conduit whereby heat energy from the heating element heats fluid passing through the fluid flow pathway. A casing is provided to sealedly surround the heating element. An exterior surface of the casing is in communication with a space into which heated fluid or vapour is emitted from the outlet of the inner conduit. The casing is heat conductive such that heat energy is received from the heating element heats fluid within said space. Fluid such as water can be efficiently heated by passing it through the fluid flow pathway and having it contact the exterior surface of the casing for double heating. Also, by restricting water flow through the fluid flow pathway can result in easy generation of steam. By having a fluid flow pathway through the heating element, this results in more efficient heating of water and saving in energy. Furthermore, it maintains the operating temperature of the heating element at a lower range thereby the life of the heating element is extended.

Description

TECHNICAL FIELD

The invention relates to a device for heating and/or vaporizing a fluid and particularly, but not exclusively to heating and/or vaporizing a medium such as water.

BACKGROUND ART

Heating water is a daily requirement and there are varied methods of doing so. With an accelerated pace of life, the requirements for water heaters are greater, i.e. there is a requirement for water heaters to heat water to boiling point or above much quicker than current devices.

An existing liquid heater, as shown in FIGS. 1 to 3, comprises a heat conductive tube 3 surrounding a coiled wire heating element 4. Electrical terminals 1 supply electric power to the heating element 4. The heating element terminals 1 are electrically insulated from the tube 3 by end caps 2 which also seal the ends of tube 3 from liquid ingress. A heat conducting, but electrically insulating powder 5 fills the space within the tube 3 surrounding the heating element 4. Heating a fluid such as water using this device relies on contact of the water with the outer surface of the tube 3. This does not provide rapid transfer of heat from the heating element 4 to the water. Furthermore, when the user switches the heater off, an internal core temperature of the heater remains at a very high level for some time resulting in a shortening of the life of the heating element.

Thus, there are a number of disadvantages with the known heater. One disadvantage is due to heating only being provided by the outer wall of the heater. This leads to user complaints of slowness in heating water and also leads to energy wastage.

Another disadvantage is due to heating by only the outer heater wall is that this prevents heat being removed from close to the heating element when power is switched off which results in a shortening of the life of the heating element and thus of the heater.

DISCLOSURE OF INVENTION

Technical Problem

An object of the invention is to mitigate or obviate to some degree one or more problems associated with known water heaters.

The above object is met by the combination of features of the main claims; the sub-claims disclose further advantageous embodiments of the invention.

Another object of the invention is to provide a heating device for more efficiently providing heated water and/or steam.

One skilled in the art will derive from the following description other objects of the invention. Therefore, the foregoing statements of object are not exhaustive and serve merely to illustrate some of the many objects of the present invention.

SOLUTION TO PROBLEM

Technical Solution

In a first main aspect, the invention provides a device for heating and/or vaporizing a fluid. The device comprises a heat conductive inner conduit having an interior surface defining a fluid flow pathway therethrough and an outlet for emitting heated fluid or vapour from the fluid flow pathway. An electrically powered heating element is arranged near to an exterior surface of said inner conduit whereby heat energy from the heating element is received at the exterior surface of the inner conduit and conducted by the inner conduit to its interior surface to heat fluid passing through the fluid flow pathway. A casing may sealably surround the heating element, said casing having an exterior surface in communication with a space into which heated fluid or vapour is emitted from the outlet of the inner conduit, said casing being heat conductive such that heat energy received from the heating element is conducted by the casing to its exterior surface to heat fluid within said space.

In a second main aspect, the invention provides a household electrical appliance having a device according to the first main aspect of the invention.

In a third main aspect, the invention provides a device for heating and/or vaporizing a fluid. The device comprises an electrically powered heating element arranged around an inner conduit defining a first fluid flow pathway to heat fluid flowing through said first fluid flow pathway. A housing surrounds the heating element and inner conduit and defines a second fluid flow pathway arranged to be heated by the heating element. An inlet of the second fluid flow pathway is connected to an outlet of the first fluid flow pathway whereby heated fluid or vapour emitted from the first fluid flow pathway is further heated in the second fluid flow pathway.

In a fourth main aspect, the invention provides a household electrical appliance having a device according to the third main aspect of the invention.

ADVANTAGEOUS EFFECTS OF INVENTION

Advantageous Effects

A purpose of the invention is to provide an improved heating device that can easily replace a conventional heating device and which provides high energy conversion efficiency whilst being easy to install and manufacture.

This purpose is achieved by the invention as defined in the appended claims.

The summary of the invention does not necessarily disclose all the features essential for defining the invention; the invention may reside in a sub-combination of the disclosed features.

BRIEF DESCRIPTION OF DRAWINGS

Description of Drawings

The foregoing and further features of the present invention will be apparent from the following description of preferred embodiments which are provided by way of example only in connection with the accompanying figures, of which:

FIG. 1 is a schematic diagram of a prior art heating tube;

FIG. 2 is a sectional view taken along A-A of FIG. 1;

FIG. 3 is an enlarged view of section B the heating tube of FIG. 1;

FIG. 4 is a schematic diagram of a first embodiment of a heating device according to the invention;

FIG. 5 is a sectional view taken along A-A of FIG. 4;

FIG. 6 is an enlarged view of section B the heating device of FIG. 4;

FIG. 7 is a perspective view of a heating device according to a second embodiment of the invention.

FIG. 8 is a sectional view of the heating device of FIG. 7;

FIG. 9 is an exploded view of the components of the heating device of FIG. 7;

FIG. 10 is a plan view of a heating device according to a third embodiment of the invention;

FIG. 11 is a sectional view of the heating device of FIG. 10; and

FIG. 12 is an exploded view of the components of the heating device of FIG. 11.

MODE FOR THE INVENTION

Mode for Invention

The following description is of preferred embodiments by way of example only and without limitation to the combination of features necessary for carrying the invention into effect.

Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments.

Referring to FIGS. 4 to 6, shown is a first embodiment of a heating device or apparatus according to the invention which is capable of rapidly heating water to high temperatures and/or of rapidly producing steam.

The heating device comprises an inner conduit in the form of a central tube 1, a casing comprising an outer conduit in the form of an outer tube 2, an insulating sleeve 3, a heating element in the form of a heating wire 4, an electrical terminal for the heating element in the form of an electrically conducting pipe 5, and an insulating ring 6. The central tube 1 defines a fluid flow pathway through which a fluid such as water passes to be heated, the tube having an inlet at one end to admit a fluid and an outlet an its other end to emit a heated fluid or vapour to a space surrounding the heating device. The heating element is located near to an exterior surface of the central tube 1 to heat it. In a preferred arrangement, the heating wire 4 comprises a coiled heating wire which is coiled around the exterior surface of the central tube, but preferably not touching it, particularly where the central tube is made of a material that is not only heat conductive but electrically conductive. A magnesium oxide powder layer 7 is provided between the heating wire 4 and the central tube 1 as well as between the heating wire 4 and the outer tube 2. The powder has electrical insulation properties as well as thermal insulating properties such that heat from the heating wire 4 slowly dissipates through the powder to the central tube 1 and outer tube 2. The outer tube 2 surrounds the heating wire 4 and seals it from ingress of fluid into the space filled by the powder 7. Both ends of the heating wire 4 are electrically connected, e.g. welded, to their respective terminal pipes 5 to receive electrical power. The terminal pipe 5 is electrically insulated from the central tube 1 by the insulting sleeve 3 and electrically insulated from the outer tube 2 by the insulating ring 6. The insulating sleeve 3 extends beyond both ends of the terminal pipe 5 to enhance electrical insulation. The outer tube 2 has a greater diameter than the central tube 1 and is arranged coaxially with the central tube 1 to sealably surround the heating wire 4 arranged around the exterior surface of the central tube 1.

In use, when a fluid such as water flows through the central tube 1 it becomes heated by heat transference from the heating wire 4 to the central tube 1 and then to the fluid. Heated fluid emitted from the outlet of the central tube 1 may be emitted to a space comprising a chamber, vessel or receptacle of a household electrical appliance such as a kettle or steamer or the like. The fluid that is admitted to the inlet of the central tube 1 may comprise already heated fluid from the space or unheated fluid from another source. In any event, heated fluid or vapour emitted from the central tube 1 into the space is further heated by the outer tube 2 through contact with its exterior surface by heat transference from the heating wire 4 to the outer tube 2.

By admitting a fluid to be heated to the fluid flow pathway through the central tube 1, this has the advantage of not only increasing heat transference efficiency and thus energy efficiency, but also has the advantage that heat dissipates more quickly away from the heating wire 4 after power is switched off. Furthermore, as heat transference efficiency is improved, the heating wire 4 does not reach the excessive temperatures encountered in the prior art devices and consequently the life of the heating wire 4 of the present invention is greatly enhanced.

In laboratory measurements, the core temperature of the heating tube was found to be 900° C., but the temperature of the tube surface was found to be 220° C. Because of this improvement, the centre of the central tube will absorb heat faster and better and transfer this to fluid passing therethrough very efficiently.

In some embodiments, a pump may be provided to urge fluid to flow through the central tube 1. In some embodiments, means may be provided to restrict the amount of fluid admitted to the central tube in order that such fluid that is admitted is rapidly heated to at least its vaporization temperature and is thus emitted from the central tube 1 as a vapour, e.g. as steam.

It will be understood that the shape and configuration of the heating device as described above is not limited to the particular embodiment shown.

Referring now to FIGS. 7 to 9, shown is a second embodiment of a heating device or vaporizer apparatus according to the invention. In this embodiment, the heating apparatus comprises the heating device of the first embodiment of FIGS. 4 to 6 with the addition of a housing 8. Therefore, like numerals to those used in FIGS. 4 to 6 will be used to denote like parts. The housing 8 surrounds the outer tube 2 to define a cylindrical annular heating space or chamber 10 around the exterior surface of the heating device. As a consequence, the space into which heated fluid or vapour is emitted from the outlet of the central tube 1 of the heating device comprises a space 10 defined by the exterior surface of the outer tube 2 and an interior surface of the housing 8 sealably surrounding said outer tube 2. The housing 8 has an outlet 11 for emitting heated fluid or vapour from said space 10. The housing 8 comprises a section of conduit of greater diameter than the outer tube 2 which is arranged coaxially with the central tube 1 and outer tube 2. Sealing rings 12 are provided for sealing the ends of the conduit around the outer tube 2. The outlet of the central tube 1 extends to an inlet of the housing 8 and may do so by extending interiorly of outer tube 2 to the housing 8 or, as shown, exteriorly of both the central tube 1 and the housing 8 to be connected to said inlet of the housing by an external connection pipe 9.

It can be seen that the space or chamber 10 comprises an annular cylindrical chamber surrounding the outer tube 2. Preferably, this is arranged such that a distance from the exterior surface of the outer tube 2 to the interior surface of the housing 8 is less than the diameter of the outer tube 2 to provide a shallow chamber 10 for further heating of fluid or vapour being emitted from the outlet of the central tube 1.

In essence, the apparatus of the embodiment of FIGS. 7 to 9 comprises the heating wire 4 arranged around the central tube 1 which defines a first fluid flow pathway to heat fluid flowing through said first fluid flow pathway with the housing 8 surrounding the heating wire 4 and central tube 1 (and outer tube 2) and defining a second fluid flow pathway for further heating fluid or vapour emitted from the first fluid flow pathway.

The second fluid flow pathway is oppositely directed to the first fluid flow pathway which is advantageous in that it assists in maintaining an even heat gradient over the length of the heating wire 4.

In some embodiments, a pump may be provided to force fluid to flow through the first and second fluid flow pathways.

In some embodiments, a fluid flow controller may be provided to restrict fluid flow through the first and second fluid flow pathways such that said fluid is vaporized as it passes through said pathways and is emitted as a vapour at the outlet of the second fluid flow pathway, i.e. at the outlet of the housing.

In some embodiments, a space into which heated fluid or vapour is emitted from the outlet of second fluid flow pathway, i.e. from the outlet of the housing 8, comprises a chamber, vessel or receptacle defined by a household electrical appliance.

In use, when a fluid such as water flows through the central tube 1 it becomes heated by heat transference from the heating wire 4 to the central tube 1 and then to the fluid. Heated fluid or vapour emitted from the outlet of the central tube 1 is admitted at the inlet of the housing 8 to the chamber 10 formed thereby for further heating through contact with the exterior surface of the outer tube 2. By making the chamber 10 defined by the housing 8 shallow in depth, i.e. having a small depth compared to the diameter of the outer tube 2, this greatly increased the rapidity with which water flowing through the first and second fluid flow passages can be heated to or above boiling point or even to produce steam.

It will be understood that the shape and configuration of the heating apparatus as described above is not limited to the particular embodiment shown.

Referring now to FIGS. 10 to 12, this shows another embodiment of a heating apparatus of the type shown by FIGS. 7 to 9 which is also based on the heating device of FIGS. 4 to 6. In this embodiment, there are provided two heating devices according to the embodiment of FIGS. 4 to 6 arranged within a common housing 8 in a side by side arrangement. In similar manner to the embodiment of FIGS. 7 to 9, the housing 8 defines a shallow chamber 10 around the outer tubes 2 of the heating devices. The outlet of each heating device connects to a respective inlet of the housing 8, but the housing has a single outlet 11 for emitting heated fluid or vapour to its exterior. Each of the heating devices also has a respective inlet for admitting fluid to their respective central tubes 1, but the inlets may be joined by a Y-shaped tubular member 10 for connection to a single source of incoming fluid.

It will be understood that the shape and configuration of the heating apparatus as described above is not limited to the particular embodiment shown.

In general, the invention provides a device for heating and/or vaporizing a fluid. The device comprises a heat conductive inner conduit defining a fluid flow pathway therethrough. An electrically powered heating element is arranged to surround said inner conduit whereby heat energy from the heating element heats fluid passing through the fluid flow pathway. A casing is provided to sealably surround the heating element. An exterior surface of the casing is in communication with a space into which heated fluid or vapour is emitted from the outlet of the inner conduit. The casing is heat conductive such that heat energy received from the heating element heats fluid within said space. Fluid such as water can be efficiently heated by passing it through the fluid flow pathway and having it contact the exterior surface of the casing for double heating. Also, by restricting water flow through the fluid flow pathway can result in easy generation of steam. By having a fluid flow pathway through the heating element, this results in more efficient heating of water and saving in energy. Furthermore, it maintains the operating temperature of the heating element at a lower range thereby extending the life of the heating element.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only exemplary embodiments have been shown and described and do not limit the scope of the invention in any manner. It can be appreciated that any of the features described herein may be used with any embodiment. The illustrative embodiments are not exclusive of each other or of other embodiments not recited herein. Accordingly, the invention also provides embodiments that comprise combinations of one or more of the illustrative embodiments described above. Modifications and variations of the invention as herein set forth can be made without departing from the spirit and scope thereof, and, therefore, only such limitations should be imposed as are indicated by the appended claims.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art.

Claims

1-37. (canceled)

38. A device for heating and/or vaporizing a fluid comprising:

a heat conductive inner conduit having an interior surface defining a fluid flow pathway therethrough and an outlet for emitting heated fluid or vapour from the fluid flow pathway;

an electrically powered heating element arranged near to an exterior surface of said inner conduit whereby heat energy from the heating element is received at the exterior surface of the inner conduit and conducted by the inner conduit to its interior surface to heat fluid passing through the fluid flow pathway;

a casing sealably surrounding the heating element, said casing having an exterior surface in communication with a space into which heated fluid or vapour is emitted from the outlet of the inner conduit, said casing being heat conductive such that heat energy received from the heating element is conducted by the casing to its exterior surface to heat fluid within said space.

39. The device of claim 38, wherein the heating element comprises a coiled wire electrically powered heating element which surrounds the exterior surface of the heat conductive inner conduit.

40. The device of claim 38, wherein the casing comprises an outer conduit of greater diameter than the inner conduit and arranged coaxially with the inner conduit to sealably surround the heating element arranged around the exterior surface of the inner conduit.

41. The device of claim 38, wherein the inner conduit has an inlet for admitting fluid to the fluid flow pathway.

42. The device of claim 41, wherein said inlet of the inner conduit is in communication with the space into which heated fluid or vapour is emitted from the outlet of the inner conduit whereby fluid from said space can be readmitted to the fluid flow pathway for further heating or vaporization.

43. The device of claim 42, wherein a fluid flow controller is provided to restrict fluid flow through the inlet to the fluid flow pathway such that said fluid is vaporized as it passes through the fluid flow pathway and is emitted as a vapour at the outlet of the inner conduit.

44. The device of claim 38, wherein said space into which heated fluid or vapour is emitted from the outlet of the inner conduit comprises a space defined by the exterior surface of the outer conduit and an interior surface of a housing sealably surrounding said outer conduit, said housing have an outlet for emitting heated fluid or vapour from said space.

45. The device of claim 44, wherein said housing comprises a third conduit of greater diameter than the cater conduit and arranged coaxially with the inner and outer conduits to sealably surround the outer conduit.

46. The device of claim 45, wherein a distance from the exterior surface of the outer conduit to the interior surface of the housing is less than the diameter of the outer conduit.

47. A device for heating and/or vaporizing a fluid comprising:

an electrically powered heating element arranged around an inner conduit defining a first fluid flew pathway to heat fluid flowing through said first fluid flow pathway;

a housing surrounding the heating element and inner conduit and defining a second fluid flow pathway arranged to foe heated by the heating element, an inlet of the second fluid flow pathway being connected to an cutlet of the first fluid flow pathway whereby heated fluid or vapour emitted from the first fluid flow pathway is further heated in the second fluid flow pathway, wherein the second fluid flow pathway is oppositely directed to the first fluid flow pathway.

48. The device of claim 47, wherein the heating element comprises a coiled wire electrically powered heating element which is coiled around the inner conduit to surround the exterior surface of the inner conduit.

49. The device of claim 47, wherein a casing comprising an outer conduit of greater diameter than the inner conduit is arranged coaxially with the inner conduit to sealably surround the heating element arranged around the exterior surface of the inner conduit.

50. The device of claim 47, wherein the inner conduit has an inlet for admitting fluid to the first fluid flow pathway.

51. The device of claim 50, wherein a fluid flow controller is provided to restrict fluid flow through the first and second fluid flow pathways such that said fluid is vaporized as it passes through said pathways is emitted as a vapour at an outlet of the second fluid flow pathway.

52. The device of claim 47, wherein a space into which heated fluid or vapour is emitted frost the outlet of second fluid flow pathway comprises a chamber, vessel or receptacle defined by a household electrical appliance.

53. The device of claim 52, wherein said housing comprises a third conduit of greater diameter than the outer conduit and arranged coaxially with the inner and outer conduits to surround the outer conduit.

54. The device of claim 53, wherein the outlet of the first fluid flow pathway extends exteriorly of both the inner conduit and the housing and is connected to the inlet of the second fluid flow pathway by an external connection pipe.

55. The device of claim 53, wherein said space comprises an annular cylindrical chamber surrounding the outer conduit.

56. The device of claim 55, wherein a distance from the exterior surface of the outer conduit to the interior surface of the housing is less than the diameter of the outer conduit.

57. A household electrical appliance having a device according to claim 38.