CN213248461U

CN213248461U - Heating device and water dispenser

Info

Publication number: CN213248461U
Application number: CN202021625896.XU
Authority: CN
Inventors: 潘跃进
Original assignee: Ningbo Jiayin Electrical And Mechanical Technology Co ltd
Current assignee: Ningbo Jiayin Electrical And Mechanical Technology Co ltd
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2021-05-25
Anticipated expiration: 2030-08-07

Abstract

The utility model relates to a heating device and water dispenser, this heating device includes: the water inlet is positioned below the water outlet; the heating parts are arranged in the shell at intervals, a liquid flow channel for communicating the water inlet with the water outlet is formed between the heating parts and the shell, the shell is respectively provided with contact parts corresponding to two opposite sides of the heating parts, and the contact parts are in contact with the heating parts; and the temperature controller is arranged on the outer surface of the shell and is in contact with one of the contact parts. The heating device of the scheme has higher heating efficiency, can meet the demand of instant heating, can effectively avoid the dry burning phenomenon, and improves the safety performance.

Description

Heating device and water dispenser

Technical Field

The utility model relates to a heating technology field especially relates to a heating device and water dispenser.

Background

Some water supply devices (such as water dispensers, water heaters and the like) are provided with heating devices, and hot water is supplied by heating water through the heating devices. At present, the heating efficiency of the heating device on the market is generally lower, the demand of instant heating cannot be met, and the heating device is easy to cause dry burning phenomenon and has poor safety performance.

SUMMERY OF THE UTILITY MODEL

Therefore, a need exists for a heating device and a water dispenser, which have higher heating efficiency, can meet the demand of instant heating, can effectively avoid the dry-fire phenomenon, and improve the safety performance.

A heating device, comprising:

the water inlet is positioned below the water outlet;

the heating parts are arranged in the shell at intervals, a liquid flow channel for communicating the water inlet with the water outlet is formed between the heating parts and the shell, the shell is respectively provided with contact parts corresponding to two opposite sides of the heating parts, and the contact parts are in contact with the heating parts; and

the temperature controller is arranged on the outer surface of the shell and is in contact with one of the contact parts.

When the heating device works, cold water supplied by an external water supply system enters the liquid flow channel from the water inlet, the water flow is heated by the heating element in the process of being conveyed along the liquid flow channel, and finally hot water is output from the water outlet. Because the water flow can be heated by the heating element in the conveying process, the heating efficiency is higher, and the instant heating requirement can be met. The water inlet is positioned below the water outlet, so that water flows in and out, and the inside of the liquid flow channel can be fully filled with water in a water passing state, and the dry burning phenomenon cannot occur; and be provided with the temperature controller in the casing outside, correspond on the casing and be equipped with the contact site, the temperature controller passes through the contact site and contacts with the surface of heating member to ensure that the temperature controller can accurately detect the operating temperature of heating member, when the temperature that the temperature controller detected surpassed preset temperature, the temperature controller can in time be with heating device's circuit disconnection, avoids appearing the dry combustion method phenomenon. The heating device of the scheme has higher heating efficiency, can meet the demand of instant heating, can effectively avoid the dry burning phenomenon, and improves the safety performance.

In one embodiment, the outer surface of the housing is recessed to form the contact portion, and the thermostat is mounted in a cavity of one of the contact portions.

In one embodiment, the housing comprises a housing body, a water inlet end cover and a water outlet end cover, the housing body is in a vertically extending cylindrical shape with two open ends, the water inlet end cover is connected with the lower port of the housing body through a first joint in a sealing manner, the water outlet end cover is connected with the upper port of the housing body through a second joint in a sealing manner, the water inlet is arranged on the water inlet end cover, the water outlet is arranged on the water outlet end cover, and the contact part is arranged on the housing body.

In one embodiment, the water outlet end cover is provided with a temperature sensing probe inserted into the liquid flow channel.

In one embodiment, the outer peripheral surface of the shell body is provided with a first positioning piece and a second positioning piece, the first positioning piece and the second positioning piece are respectively arranged close to two ends of the shell body, one side, away from the water inlet end cover, of the first joint is abutted against the first positioning piece, and one side, away from the water outlet end cover, of the second joint is abutted against the second positioning piece.

In one embodiment, the first positioning element and the second positioning element are both annular pieces sleeved on the outer peripheral surface of the shell body, and connecting pieces attached to the outer surface of the shell body are respectively arranged on the peripheries of inner holes of the first positioning element and the second positioning element.

In one embodiment, the terminal of the heating element penetrates through the water inlet end cover, a sealing gasket is sleeved on the periphery of the heating element, and the water inlet end cover is connected with the heating element in a sealing mode through the sealing gasket.

In one embodiment, the outer end face of the water inlet end cover is provided with a pressing sheet, the periphery of the sealing gasket is provided with a flange, the flange is clamped between the water inlet end cover and the pressing sheet, the pressing sheet is provided with a through hole for the heating element to pass through, the outer peripheral surface of the terminal of the heating element is sleeved with a third positioning piece, and one face, far away from the water inlet end cover, of the pressing sheet is abutted to the third positioning piece.

In one embodiment, a supporting seat is arranged on the outer side of the shell body.

The application also provides a water dispenser, which comprises the heating device.

The water dispenser adopts all technical schemes of all embodiments of the heating device, so that the water dispenser at least has all beneficial effects brought by the technical schemes of the embodiments, and details are not repeated.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a heating device according to an embodiment of the present invention;

FIG. 2 is a schematic side view of the heating apparatus of FIG. 1;

FIG. 3 is a schematic view of a first cross-sectional structure of the heating apparatus of FIG. 1;

FIG. 4 is a schematic diagram of a second cross-sectional structure of the heating apparatus of FIG. 1;

fig. 5 is an exploded view of the heating apparatus of fig. 1.

101. A water inlet; 102. a water outlet; 11. a housing body; 111. a contact portion; 12. a water inlet end cover; 13. a water outlet end cover; 14. a first joint; 15. a second joint; 16. a first positioning member; 161. connecting sheets; 17. a second positioning member; 18. tabletting; 19. a third positioning member; 20. a heating member; 30. a temperature controller; 40. a temperature sensing probe; 50. a seal ring; 60. a gasket; 70. and (4) supporting the base.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

Referring to fig. 1 and 2, a heating device according to an embodiment of the present invention includes a housing, a heating element 20, and a temperature controller 30. The shell is provided with a water inlet 101 and a water outlet 102, and the water inlet 101 is positioned below the water outlet 102. Referring to fig. 3 and 4, the heating members 20 are disposed in the casing at intervals, a fluid passage is formed between the heating members 20 and the casing to communicate the water inlet 101 and the water outlet 102, the casing is respectively provided with contact portions 111 at two opposite sides corresponding to the heating members 20, and the contact portions 111 are in contact with the heating members 20. The thermostat 30 is disposed on the outer surface of the housing and contacts with one of the contact portions 111.

When the heating device works, cold water supplied by an external water supply system enters the liquid flow channel from the water inlet 101, the water flow is heated by the heating element 20 in the process of being conveyed along the liquid flow channel, and finally hot water is output from the water outlet 102. Because the water flow can be heated by the heating element 20 in the conveying process, the heating efficiency is higher, and the instant heating requirement can be met. The water inlet 101 is positioned below the water outlet 102, so that water flows in and out, and under the water passing state, the inside of the liquid flow channel can be fully filled with water, and the dry burning phenomenon cannot occur; and be provided with temperature controller 30 outside the casing, correspond on the casing and be equipped with contact site 111, temperature controller 30 contacts through the surface of contact site 111 with heating member 20 to ensure that temperature controller 30 can accurately detect the operating temperature of heating member 20, when the temperature that temperature controller 30 detected surpassed preset the temperature, temperature controller 30 can in time be with heating device's circuit disconnection, avoid appearing the dry combustion method phenomenon. The heating device of the scheme has higher heating efficiency, can meet the demand of instant heating, can effectively avoid the dry burning phenomenon, and improves the safety performance.

Specifically, the temperature controller 30 is also called a temperature controller, and can be physically deformed inside the switch according to the temperature change of the working environment, so as to generate some special effects, and generate a series of automatic control elements that are turned on or off, or the electronic elements provide temperature data for the circuit according to the difference of the working states at different temperatures, so as to enable the circuit to acquire the temperature data. The specific operation principle of the thermostat 30 is well known to those skilled in the art and will not be described in detail herein.

Further, as shown in fig. 3, in the present embodiment, the outer surface of the housing is recessed to form a contact portion 111, and the thermostat 30 is installed in a cavity of one of the contact portions 111. In this way, the two contact portions 111 are recessed inward to a height just enough to ensure contact with the surface of the heating element 20, and the recessed cavity formed by the contact portions 111 can provide a suitable installation space for the thermostat 30.

Further, please refer to fig. 1, fig. 4 and fig. 5, the housing includes a housing body 11, a water inlet end cover 12 and a water outlet end cover 13, the housing body 11 is a cylindrical shape extending vertically and having two open ends, the water inlet end cover 12 is connected to the lower port of the housing body 11 through a first joint 14 in a sealing manner, the water outlet end cover 13 is connected to the upper port of the housing body 11 through a second joint 15 in a sealing manner, the water inlet 101 is disposed on the water inlet end cover 12, the water outlet 102 is disposed on the water outlet end cover 13, and the contact portion 111 is disposed on the housing body 11.

Specifically, in this embodiment, the housing body 11 may be made of stainless steel, the housing body 11 is in a vertically-placed cylindrical shape, and the cross-sectional shape of the housing body 11 may be designed to be circular, oval, kidney-shaped, square, etc. according to actual requirements. For example, in the present embodiment, the heating member 20 is provided in a U shape, and the case body 11 is provided in a cylindrical structure having a waist-shaped cross section in order to fit the shape of the heating member 20. The first joint 14 is sleeved on the lower end of the shell body 11, a sealing ring 50 is arranged between the outer circumferential surface of the shell body 11 and the inner circumferential surface of the first joint 14, the water inlet end cover 12 is sleeved on the lower end of the first joint 14, and the sealing ring 50 is arranged between the outer circumferential surface of the first joint 14 and the inner circumferential surface of the water inlet end cover 12, so that reliable sealing connection between the water inlet end cover 12 and the shell body 11 can be ensured. The water inlet 101 is arranged on the side of the water inlet end cover 12, the water inlet end cover 12 is hollow, water flow input from the water inlet 101 flows into the shell body 11 through the water inlet end cover 12 without leakage, and safety performance can be further guaranteed. In order to facilitate the external connection of the pipeline, a pipe joint protruding outwards can be arranged at the water inlet 101. Similarly, the second joint 15 is sleeved on the upper end of the shell body 11, the water outlet end cover 13 is sleeved on the upper end of the second joint 15, and the sealing rings 50 are respectively arranged between the second joint 15 and the shell body 11, between the second joint 15 and the water outlet end cover 13, so as to ensure reliable sealing connection between the water outlet end cover 13 and the shell body 11. In order to facilitate water outlet, the water outlet 102 is disposed at the bottom of the water outlet end cap 13, the water outlet end cap 13 is hollow, and water in the shell body 11 can be conveyed to the water outlet 102 through the water outlet end cap 13 and flows out without leakage. The sealing ring 50 includes, but is not limited to, an O-ring 50, a quad ring 50, and the like.

In addition, in order to regulate and control the water temperature to meet different use requirements, the water outlet end cover 13 is provided with a temperature sensing probe 40 inserted into the liquid flow channel. Specifically, in the present embodiment, the temperature sensing probe 40 may adopt an NTC (negative temperature coefficient) temperature sensing probe, which is a type of temperature sensor made of an NTC thermistor, and the resistance value of the NTC temperature sensing probe decreases with the increase of temperature, and has the advantages of high sensitivity, fast response speed, and the like. The lead of the temperature sensing probe 40 penetrates through the water outlet end cover 13 and is electrically connected with the controller of the heating device, and the controller acquires the resistance value of the temperature sensing probe 40 and converts the resistance value into corresponding temperature, so that the temperature of the water outlet end of the liquid flow channel can be monitored in real time, and the heating state of the heating element 20 is controlled according to needs, so that the regulation and control of the water temperature are realized. Of course, in other embodiments, other types of temperature sensing probes may be used as long as temperature detection is achieved.

Further, in this embodiment, the outer peripheral surface of the housing body 11 is provided with a first positioning element 16 and a second positioning element 17, the first positioning element 16 and the second positioning element 17 are respectively disposed near two ends of the housing body 11, one side of the first joint 14 far away from the water inlet end cover 12 abuts against the first positioning element 16, and one side of the second joint 15 far away from the water outlet end cover 13 abuts against the second positioning element 17. Through setting up first setting element 16 and second setting element 17, can play reliable location and limiting displacement to the installation of first joint 14 and second joint 15, guarantee the assembly reliability.

Specifically, in this embodiment, the first positioning element 16 and the second positioning element 17 are both annular pieces sleeved on the outer peripheral surface of the shell body 11, and the inner hole peripheries of the first positioning element 16 and the second positioning element 17 are respectively provided with a connecting piece 161 attached to the outer surface of the shell body 11. Wherein, the annular sheet can be a continuous whole circle or can be formed by combining discontinuous multi-section structures. When assembling, the two ends of the shell body 11 are respectively sleeved with the first positioning piece 16 and the second positioning piece 17, the connecting pieces 161 on the first positioning piece 16 and the second positioning piece 17 are respectively attached to the shell body 11, and welding can be performed through spot welding or laser welding and other processes, so that the assembling is simple and reliable. For example, in the present embodiment, four connecting pieces 161 are respectively disposed on the periphery of the inner holes of the first positioning member 16 and the second positioning member 17, so as to further ensure the connection reliability.

Further, in this embodiment, the water inlet end cover 12, the first joint 14 and the first positioning element 16 are correspondingly provided with first assembling holes for the fasteners to pass through, and the water inlet end cover 12, the first joint 14 and the first positioning element 16 are locked and fixed by the fasteners; the water outlet end cover 13, the second joint 15 and the second positioning piece 17 are correspondingly provided with second assembling holes for the fasteners to pass through, and the water outlet end cover 13, the second joint 15 and the second positioning piece 17 are locked and fixed through the fasteners. The fastening piece can be a screw, a bolt, a pin or the like. The assembling structure is simple and stable and reliable in assembling. Optionally, the outer peripheral surface of the first joint 14 is provided with a first limit flange abutting against the water inlet end cover 12, and the outer peripheral surface of the second joint 15 is provided with a second limit flange abutting against the water outlet end cover 13, so that the assembly reliability can be further improved.

Further, referring to fig. 3 and fig. 4, in the present embodiment, the terminal of the heating element 20 penetrates through the water inlet end cover 12, a sealing gasket 60 is sleeved on the periphery of the heating element 20, and the water inlet end cover 12 is hermetically connected to the heating element 20 through the sealing gasket 60. The sealing gasket 60 is provided to form a reliable sealing connection between the heating element 20 and the water inlet end cap 12, so as to avoid water leakage. Specifically, in the present embodiment, the heating member 20 is a U-shaped heating pipe arranged in a U-shape, both terminals of the heating member 20 penetrate out from the bottom of the water inlet end cover 12, and accordingly, the sealing gasket 60 may be arranged in a "∞" type structure. The gasket 60 may be made of rubber or silica gel having good heat resistance. By adopting the U-shaped heating pipe, the heating area can be increased as much as possible in a limited space, and the heating efficiency of the heating device can be further improved. Of course, in other embodiments, the heating element 20 may be provided as a straight tubular, serpentine, or spiral heating tube, or the like.

Further, in this embodiment, the outer end face of the water inlet end cover 12 is provided with a pressing sheet 18, the periphery of the sealing gasket 60 is provided with a flange, the flange is clamped between the water inlet end cover 12 and the pressing sheet 18, the pressing sheet 18 is provided with a through hole for the heating element 20 to pass through, the outer peripheral surface of the terminal of the heating element 20 is sleeved with a third positioning element 19, and one face of the pressing sheet 18, which is far away from the water inlet end cover 12, abuts against the third positioning element 19. Specifically, during assembly, the sealing gasket 60 is sleeved on the heating element 20, the flange of the sealing gasket 60 is abutted against the water inlet end cover 12, the pressing sheet 18 is pressed on the outer end face of the water inlet end cover 12, the pressing sheet 18 presses the other side of the flange of the sealing gasket 60, the third positioning member 19 is sleeved on the heating element 20, and the third positioning member 19 and the heating element 20 can be welded and fixed through spot welding or laser welding. By adopting the assembly structure, the sealing reliability can be further ensured. Alternatively, the third positioning member 19 includes an annular positioning piece and a sleeve extending downward from an inner annular hole of the positioning piece, and the sleeve is closely attached to the outer peripheral surface of the heating member 20 for facilitating welding.

Optionally, in this embodiment, the third positioning element 19, the pressing sheet 18 and the water inlet end cover 12 are respectively and correspondingly provided with a third assembling hole for the fastening element to penetrate through, and the third positioning element 19, the pressing sheet 18 and the water inlet end cover 12 are locked and fixed by the fastening element, so that the assembly is simple and convenient, and the assembly reliability can be further ensured. The fasteners include, but are not limited to, screws, bolts, or pins.

In addition, in order to facilitate mounting of the heating apparatus as a whole to other equipment, in the present embodiment, a support seat 70 is provided on the outer side of the case body 11. Specifically, as shown in fig. 1, in the present embodiment, the supporting base 70 is substantially in a shape like a Chinese character 'ji', and the supporting base 70 includes a connecting plate connected to the shell body 11, bending plates disposed on two opposite sides of the connecting plate and extending toward a side away from the shell body 11, and fixing plates respectively connected to the bending plates, and each fixing plate is provided with a fixing hole. Wherein, the connecting plate can adopt modes such as spot welding or laser welding with the surface of shell body 11 to be connected to guarantee to connect the reliability. Optionally, at least two protruding welding spots are arranged on the connecting plate, so that the welding reliability can be further ensured.

Alternatively, in this embodiment, the housing body 11 is a flat structure and has two opposite flat surfaces, wherein the flat surface on one side can be formed with an inwardly recessed first contact portion 111 through a pressing process for mounting the thermostat 30, and the flat surface on the other side can be formed with an inwardly recessed second contact portion 111 through a pressing process, so that the second contact portion 111 can be made relatively smaller in size because the thermostat 30 does not need to be mounted on the second contact portion 111. The connecting plate of the supporting seat 70 is attached to and welded with the plane of the side of the housing where the second contact portion 111 is provided, so that the welding stability can be ensured. In addition, in order to ensure the installation reliability of the heating device and other equipment, the number of the supporting seats 70 may be two or more. For example, in the present embodiment, the support seats 70 are provided in two, and the two support seats 70 are arranged at intervals in the extending direction of the case body 11.

The utility model discloses still provide a water dispenser, this water dispenser includes heating device, and this heating device's concrete structure refers to above-mentioned embodiment, because this water dispenser has adopted the whole technical scheme of above-mentioned all embodiments, consequently has all beneficial effects that the technical scheme of above-mentioned embodiment brought at least, and the repeated description is no longer given here.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present application, unless expressly stated or limited otherwise, the first feature may be directly on or directly under the second feature or indirectly via intermediate members. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Claims

1. A heating device, comprising:

the water inlet is positioned below the water outlet;

2. The heating device of claim 1, wherein an outer surface of the housing is recessed to form the contact portion, and the thermostat is mounted in a cavity of one of the contact portions.

3. The heating device according to claim 1 or 2, wherein the housing comprises a housing body, a water inlet end cover and a water outlet end cover, the housing body is in a cylindrical shape which extends vertically and is open at two ends, the water inlet end cover is connected with the lower port of the housing body in a sealing manner through a first joint, the water outlet end cover is connected with the upper port of the housing body in a sealing manner through a second joint, the water inlet is arranged on the water inlet end cover, the water outlet is arranged on the water outlet end cover, and the contact portion is arranged on the housing body.

4. The heating device of claim 3, wherein the outlet end cap is provided with a temperature sensing probe inserted into the flow channel.

5. The heating device as claimed in claim 3, wherein a first positioning member and a second positioning member are disposed on the outer circumferential surface of the housing body, the first positioning member and the second positioning member are respectively disposed near two ends of the housing body, one side of the first joint far away from the water inlet end cover abuts against the first positioning member, and one side of the second joint far away from the water outlet end cover abuts against the second positioning member.

6. The heating device of claim 5, wherein the first positioning element and the second positioning element are both annular pieces sleeved on the outer peripheral surface of the shell body, and connecting pieces attached to the outer surface of the shell body are respectively arranged on the peripheries of inner holes of the first positioning element and the second positioning element.

7. The heating device according to claim 3, wherein the terminal of the heating element penetrates through the water inlet end cover, a sealing gasket is sleeved on the periphery of the heating element, and the water inlet end cover is connected with the heating element in a sealing mode through the sealing gasket.

8. The heating device according to claim 7, wherein a pressing sheet is arranged on the outer end face of the water inlet end cover, a flange is arranged on the periphery of the sealing gasket, the flange is clamped between the water inlet end cover and the pressing sheet, the pressing sheet is provided with a through hole for the heating element to pass through, a third positioning piece is sleeved on the outer peripheral surface of the terminal of the heating element, and one face, far away from the water inlet end cover, of the pressing sheet is abutted against the third positioning piece.

9. A heating device as claimed in claim 3, characterized in that the housing body is provided with a support seat on its outer side.

10. A water dispenser characterized by comprising a heating device as claimed in any one of claims 1 to 9.