A hybrid heater for heating an oven, an oven comprising the hybrid heater, a method for operating the hybrid heater

Abstract

A hybrid heater for heating an oven, preferably an oven such as a bread or confectionary oven, the hybrid heater comprising: - a distribution arrangement, extending over a length in a longitudinal direction of the hybrid heater, comprising a receiving opening arranged for receiving a fuel gas and an oxidant gas, such as air, or a mixture of gas thereof, and a first distribution chamber arranged for distributing the fuel gas and the oxidant gas, or the mixture of gas thereof over a length of the hybrid heater in the longitudinal direction of the hybrid heater, wherein a first wall of the distribution arrangement delimiting the first distribution chamber is provided with an outlet opening, preferably a plurality of outlet openings, for allowing the fuel gas and the oxidant gas, or the mixture of gas thereof to exit the distribution arrangement; - an electric heating arrangement, provided in the first distribution chamber, arranged for heating gas distributed in the first distribution chamber, wherein the electric heating arrangement extends over a length of the first distribution chamber in the longitudinal direction of the hybrid heater. An oven comprising the hybrid heater and a method for operating the hybrid heater.

Description

[0001] Title: A hybrid heater for heating an oven, an oven comprising the hybrid heater, a method for operating the hybrid heater

[0002] Description:

[0003] According to a first aspect of the present disclosure, the disclosure relates to a hybrid heater for heating an oven.

[0004] According to a second aspect of the present disclosure, the disclosure relates to an oven comprising the hybrid heater according to the first aspect of the present disclosure.

[0005] According to a third aspect of the present disclosure, the disclosure relates to a method for operating the hybrid heater according to the first aspect of the present disclosure.

[0006] Direct gas-fired ovens have long been utilized. Such ovens have a wide variety of applications such as for producing bricks or baking food products, such as bread or confectionary, and other heat applications. Typically, these ovens use one or more burners fueled by gas, such as natural gas. Among these are tubular pipe burners, which feature a lateral flame emitted from a longitudinal slot within the burner.

[0007] Nowadays, there is a heightened awareness about carbon footprint and many companies aim to reduce or eliminate the reliance on fossil fuels by replacing or supplementing them with electric alternatives. As a result electric heaters or heaters containing both electricity- and gas-based heating elements have been developed. Such heaters comprising electricity- and gas-based heating element are also favorable for realizing flexibility in relation to the use of the source of energy.

[0008] Such known heaters, however, may have the issue that electric components, such as the electricity-based heating elements of the heater are in direct contact with flames originating for burning gas, such that these components can only be placed at a limited number of positions in the heating device or oven. Another drawback of known heaters that are initially gas fired and thereafter heated with electric heating, thus heaters comprising both gas-based and electricitybased heating elements, require continuous air / gas flow through the burner to prevent deformation of the tubular pipe. This requires frequent replacement of components, making such heaters relatively expensive.

[0009] Within the context of the present disclosure a heater is considered a hybrid heater if the heater is flexible as regards the use of the energy source for providing the required heat.

[0010] Another frequent occurring problem with heaters having electric heating components is that the electric heating components have the risk of overheating. Security measures are taken to prevent or at least strongly reduce problems, which are often bulky or unhandy, making the heaters unnecessary large / heavy and / or expensive.

[0011] Therefore, there exists a need for a more effective and durable way of heating with reduced costs and impact on the environment.

[0012] It is an object of the present disclosure to provide a hybrid heater for heating an oven, an oven comprising the hybrid heater, and a method for operating the hybrid heater.

[0013] At least part of the above-given problems are solved by the disclosure as presented in the current document.

[0014] The hybrid heater according to the first aspect of the present disclosure comprises: a distribution arrangement, extending over a length in a longitudinal direction of the hybrid heater, comprising a receiving opening arranged for receiving a fuel gas and an oxidant gas, such as air, or a mixture of gas thereof, and a first distribution chamber arranged for distributing the fuel gas and the oxidant gas, or the mixture of gas thereof over a length of the hybrid heater in the longitudinal direction of the hybrid heater, wherein a first wall of the distribution arrangement delimiting the first distribution chamber is provided with an outlet opening, preferably a plurality of outlet openings, for allowing the fuel gas and the oxidant gas, or the mixture of gas thereof to exit the distribution arrangement; an electric heating arrangement, provided in the first distribution chamber, arranged for heating gas distributed in the first distribution chamber, wherein the electric heating arrangement extends over a length of the first distribution chamber in the longitudinal direction of the hybrid heater.

[0015] The hybrid heater according to the first aspect of the present disclosure allows a constant flow of air (the oxidant gas) around the electric heating components that prevents overheating of said heating components. In other words, (forced) convection may be established by the hybrid heater for cooling of the hot electric heating components thereby extending the lifetime of the hybrid heater.

[0016] Another advantage of the constant flow of air is that the hybrid heater can be switched on and off more quickly.

[0017] Due to the overpressure caused by the continuous flow of air through the hybrid heater, there is no risk of backfire of baking fumes via the hybrid heater to the outside.

[0018] The hybrid heater is designed such that elements of the burner are placed inside the hybrid heater instead of around the hybrid heater, which allows that the hybrid heater may be retrofitted in existing ovens.

[0019] Additionally, due to the distribution of the outlet openings, the flow of the mixture of the gas is equally distributed over the length of the first distribution chamber in the longitudinal direction of the hybrid heater, such that the flame is also distributed evenly and consistently over the length of the first distribution chamber in the longitudinal direction of the hybrid heater.

[0020] Potential mixing problems of fuel gas with oxidant gas, like air, are resolved by the hybrid heater because of the strongly improved mixing of the fuel gas, independent of the calorific value of the fuel gas, with the oxidant gas and distribution of the mixture of the gas inside the hybrid heater , i.e. , in the first distribution chamber and / or second distribution chamber, due to the equally distributed openings through which the mixture of the gas can flow. This in contrast to existing heaters, which often require adjustment of the settings and / or replacement of components if fuel gas having a different calorific value is used.

[0021] The hybrid heater can use one or more energy sources from the following nonlimiting list: electricity, natural gas, butane gas, propane gas, LPG, biogas and hydrogen (H2).

[0022] The oven according to the second aspect of the present disclosure comprises a hybrid heater according to the first aspect of the present disclosure.

[0023] The method for operating a hybrid heater according to the first aspect of the present disclosure comprises at least one of the steps of: providing the oxidant gas, via the receiving opening, to the hybrid heater; providing electrical power to the electric heating arrangement for heating the oxidant gas provided, via the receiving opening, to the hybrid heater.

[0024] Corresponding embodiments disclosed below for the first aspect are also applicable to the oven (second aspect), and the method for operating the hybrid heater (third aspect), unless stated otherwise.

[0025] Benefits of the hybrid heater according to the first aspect are also applicable to the oven according to the second aspect and the method according to the third aspect.

[0026] The hybrid heater according to the first aspect of the present disclosure may be used for heating products such as bread or confectionary up to a temperature of about 400 °C.

[0027] The length of the hybrid heater (and of the electric heating elements inside the hybrid heater) may be determined by the required heat capacity and oven dimensions. As said, the hybrid heater is suitable for heating an oven, which may be a bread or confectionary oven.

[0028] Preferably the first distribution chamber is further arranged for distributing the fuel gas and the oxidant gas, or the mixture thereof over the length of the distribution arrangement.

[0029] In an embodiment, the electric heating arrangement is arranged for maintaining a temperature of the mixture of gas below the ignition temperature of the mixture of gas. This is beneficial for allowing the use of the electric heating arrangement during presence of the gas mixture.

[0030] Preferably, the distribution chamber is provided with a plurality of outlet openings.

[0031] In this regard, it is advantageous if the plurality of outlet openings are distributed evenly along the length of the first distribution chamber. Due to the distribution of the outlet openings, the flow of the mixture of the gas is equally distributed over the length of the first distribution chamber in the longitudinal direction of the hybrid heater, such that the flame is also distributed evenly and consistently over the length of the first distribution chamber in the longitudinal direction of the hybrid heater.

[0032] In an embodiment, the hybrid heater further comprises a spacing arrangement, provided in the first distribution chamber, arranged for spacing the electric heating arrangement apart from the first wall at a predetermined distance.

[0033] Preferably, the electrical heating arrangement comprises an electrical heating element. In this regard it is beneficial if the spacing arrangement spaces the electrical heating element apart from the first wall at the predetermined distance.

[0034] In another embodiment, the electric heating arrangement comprises a plurality of electric heating elements and wherein the spacing arrangement is further arranged for spacing the plurality of electric heating elements apart from each other at a predetermined distance over a length of the plurality of electric heating elements in the longitudinal direction of the hybrid heater.

[0035] The hybrid heater may further comprise a spacing arrangement, provided in the first distribution chamber, arranged for spacing the electric heating arrangement apart from the first wall at a predetermined distance.

[0036] The power per cm2of the electric heating elements has been selected in such a way that no damage can occur to the metal casing.

[0037] There may be production-technical limitations to the production of the electric heating element with regard to its length. The curved electric heating element can bridge a distance below a predetermined length, such as approximately 1500 mm. In order to bridge a larger distance, such as for example 3000 mm or 6000 mm, it may also be possible to not bend the tubes (electric heating elements), thus to use uncurved / -bended tubes, and attach the unbended tubes to each other via spacing arrangements and position multiple electric heating elements next to each other in the longitudinal direction. Optionally, one end of the unbended electric heating elements may be sealed to prevent the mixture of gas to flow that respective end and thus, force the mixture of gas to exit the tube through the distribution openings.

[0038] Preferably, the mutual distance between the various electric heating elements is the same and the electric heating elements are not in direct contact with the first wall of the distribution arrangement. This is to prevent the first wall of the distribution arrangement from melting, which could result in a short circuit.

[0039] In an embodiment, the receiving opening is provided at a first end part of the first distribution chamber and wherein a second end part of the first distribution chamber, opposite to the first end part, is closed.

[0040] The second end part of the first distribution chamber is closed, for example by an end plate, to prevent the gas mixture or hot air from flowing away uncontrollably. In another embodiment, the hybrid heater further comprises: an inlet arrangement arranged for receiving the fuel gas and the oxidant gas, or the mixture of gas thereof; a mixture chamber, in fluid communication with the inlet arrangement, arranged for mixing the fuel gas and the oxidant gas; an outlet arrangement, in fluid communication with the mixture chamber, arranged for providing the fuel gas and the oxidant gas, or the mixture of gas thereof to the distribution arrangement.

[0041] In yet another embodiment, the distribution arrangement further comprises a second distribution chamber, provided, at least partly, inside the first distribution chamber and extending over a length of the first distribution chamber in the longitudinal direction of the hybrid heater, wherein a wall of the second distribution chamber is provided with a distribution opening, preferably a plurality of distribution openings, and the second distribution chamber is in fluid communication, via the distribution opening, with the first distribution chamber.

[0042] Preferably, the first distribution chamber is arranged for receiving the fuel gas and the oxidant gas, or the mixture of gas thereof via the distribution opening, from the receiving opening.

[0043] The distribution opening and the outlet opening are preferably displaced such that seen in a radial direction, perpendicular to the longitudinal direction, the distribution opening and the outlet opening are free from overlap, preferably wherein the plurality of distribution openings and the plurality of outlet openings are displaced such that seen in the radial direction the plurality of distribution openings and the plurality of outlet openings are free from overlap.

[0044] It may also be possible that the distribution opening and the outlet opening are displaced in a tangential direction about a virtual central axis of the second distribution chamber, extending in the longitudinal direction of the hybrid heater, preferably displaced in the tangential direction about an angle in the range of 10 degrees - 180 degrees, more preferably in the range of 90 degrees - 180 degrees, preferably wherein the plurality of distribution openings and the plurality of outlet openings are displaced in a tangential direction about a virtual central axis of the second distribution chamber, extending in the longitudinal direction of the hybrid heater, preferably displaced in the tangential direction about an angle in the range of 10 degrees - 180 degrees, more preferably in the range of 90 degrees - 180 degrees.

[0045] In an embodiment, the distribution opening and the outlet opening are displaced in the longitudinal direction of the heater, preferably wherein the distribution opening and the outlet opening are displaced in the longitudinal direction of the heater such that the distribution opening and the outlet opening are free from overlap, preferably wherein the plurality of distribution openings and the plurality of outlet openings are displaced such that the plurality of distribution openings and the plurality of outlet openings are free from overlap.

[0046] The hybrid heater may further comprise: an ignition arrangement, for example an electrode, arranged for igniting gas, preferably the mixture of gas, originating from the outlet opening.

[0047] The oxidant gas may be heated to a predetermined temperature that is above the ambient temperature before it is received by the receiving opening of the hybrid heater.

[0048] The oven according to the second aspect of the present disclosure that comprises the hybrid heater is preferably a bread oven.

[0049] In an embodiment, the oven comprises a control arrangement arranged for controlling at least one of: a flow of the fuel gas to the hybrid heater; a flow of the oxidant gas, such as air, to the hybrid heater; a flow of the mixture of the fuel gas and the oxidant gas to the hybrid heater; electrical power provided to the electric heating arrangement arranged for heating gas distributed in the first distribution chamber. The control arrangement may be further arranged for controlling electrical power provided to the ignition arrangement for igniting the mixture of gas originating from the outlet opening.

[0050] In the method according to the third aspect of the present disclosure, the steps may be executed in an order differing from the order as presented in the claims, but preferably the steps are executed in subsequent order as presented in the claims.

[0051] In an embodiment, the method further comprises at least one of the steps of: terminating the step of providing electrical power to the electric heating arrangement for allowing the electric heating arrangement to cool down; terminating the step of providing the oxidant gas, via the receiving opening, to the hybrid heater.

[0052] Preferably, the step of terminating the step of providing the oxidant gas is executed for a first predetermined period of time after the step of terminating the step of providing electrical power, preferably wherein the first predetermined period of time is in the range of 3 to 5 minutes.

[0053] In another embodiment, the method comprises the steps of: providing the fuel gas, via the receiving opening, to the hybrid heater; igniting, by the ignition arrangement, the mixture of the fuel gas and the oxidant gas; terminating the step of providing the fuel gas, via the receiving opening, to the hybrid heater; wherein the step of terminating the step of providing the oxidant gas, via the receiving opening, to the hybrid heater is executed after the step of terminating the step of providing the fuel gas, via the receiving opening, to the hybrid heater.

[0054] The step of terminating the step of providing the oxidant gas, via the receiving opening, to the hybrid heater is preferably executed after a second predetermined period of time after the step of terminating the step of providing the fuel gas, via the receiving opening, to the hybrid heater, preferably wherein the second predetermined period of time corresponds to a time range wherein the first distribution chamber, and if present, the second distribution chamber are free from the fuel gas.

[0055] The present disclosure is hereinafter explained in more detail with reference to the accompanying drawings in which embodiments of the present disclosure are shown and in which like reference numbers indicate the same or similar elements. The present disclosure is by no means limited to the embodiments described therein.

[0056] Fig. 1 schematically shows a hybrid heater according to the first aspect of the present disclosure;

[0057] Fig. 2 schematically shows a cross-sectional view in the longitudinal direction of a detailed part of the hybrid heater of Fig. 1 ;

[0058] Fig. 3 schematically shows an electric heating arrangement as comprised in the hybrid heater of Fig. 1 ;

[0059] Fig. 4 schematically shows a cross-sectional view along line A-A of the detailed part of the hybrid heater of Fig. 2;

[0060] Fig. 5 schematically shows part of an electric heating element of the electric heating arrangement of Fig. 3;

[0061] Fig. 6 schematically shows a cross-sectional view along line B-B of the electric heating arrangement of Fig. 3;

[0062] Fig. 7 schematically shows an isometric view of part of a second distribution chamber of the hybrid heater of Fig. 1 ;

[0063] Fig. 8 schematically shows a cross-sectional view in the longitudinal direction of a detailed part of the hybrid heater of Fig. 1 ;

[0064] Fig. 9 schematically shows an oven according to the second aspect of the present disclosure comprising a plurality of hybrid heaters according to the first aspect of the present disclosure; and

[0065] Fig. 10 schematically shows a method according to the third aspect of the present disclosure for operating the hybrid heater according to the first aspect of the present disclosure.

[0066] A hybrid heater 1 according to the first aspect of the present disclosure is shown in Fig. 1. The hybrid heater 1 is for heating an oven 50 and comprises a distribution arrangement 3. The distribution arrangement 3 extends over a length in a longitudinal direction L of the hybrid heater 1 and comprises a receiving opening 5 (not visible in Fig. 1) arranged for receiving a mixture of a fuel gas F and an oxidant gas O and a first distribution chamber 7 (not visible in Fig. 1) arranged for distributing the mixture of gas over a length of the hybrid heater 1 in the longitudinal direction L of the hybrid heater 1. The distribution arrangement 3 has a first wall 9 that delimits the first distribution chamber 7 and is provided with a plurality of outlet openings 11 , for allowing the mixture of gas to exit the distribution arrangement 3.

[0067] The first distribution chamber 7 is provided with a first end part 19 and a second end part 21 opposite to the first end part 19, wherein the second end part 21 is closed.

[0068] Fig. 1 further shows that the hybrid heater 1 comprises an ignition arrangement 35 arranged for igniting gas, in this case the mixture of gas, originating from the plurality of outlet openings 11 .

[0069] A cross-sectional view in the longitudinal direction L of a detailed part of the hybrid heater 1 of Fig. 1 is shown in Fig. 2. It shows that the hybrid heater 1 comprises an electric heating arrangement 13, provided in the first distribution chamber 7, arranged for heating gas distributed in the first distribution chamber 7, wherein the electric heating arrangement 13 extends over a length of the first distribution chamber 7 in the longitudinal direction L of the hybrid heater 1.

[0070] In Fig. 2 it is shown that the hybrid heater 1 further comprises spacing arrangements 15, provided in the first distribution chamber 7, arranged for spacing the electric heating arrangement 13 apart from the first wall 9 at a predetermined distance. Furthermore, the electric heating arrangement 13 comprises a plurality of electric heating elements 17 (two are shown) and wherein the spacing arrangements 15 are further arranged for spacing the plurality of electric heating elements 17 apart from each other at a predetermined distance over a length of the plurality of electric heating elements 17 in the longitudinal direction L of the hybrid heater 1. As can be seen in Fig. 2, the receiving opening 5 is provided at the first end part 19 of the first distribution chamber 7.

[0071] Fig. 2 further shows that the hybrid heater 1 further comprises an inlet arrangement 23, 25 arranged for receiving the fuel gas F or the oxidant gas O, respectively, a mixture chamber 27, in fluid communication with the inlet arrangement 23, 25, arranged for mixing the fuel gas F and the oxidant gas O, and an outlet arrangement 29, in fluid communication with the mixture chamber 27, arranged for providing the mixture of the gas to the distribution arrangement 3.

[0072] The distribution arrangement 3 further comprises a second distribution chamber 31 , provided, at least partly, inside the first distribution chamber 7 and extending over a length of the first distribution chamber 7 in the longitudinal direction L of the hybrid heater 1 , wherein the second distribution chamber 31 has a wall 32. The wall 32 is provided with a plurality of distribution openings 33 (not shown in Fig. 2), and the second distribution chamber 31 is in fluid communication, via the distribution openings 33, with the first distribution chamber 7. The first distribution chamber 7 is arranged for receiving the mixture of gas via the distribution openings 33, from the receiving opening 5.

[0073] Fig. 3 shows an electric heating arrangement 13 as comprised in the hybrid heater 1 of Fig. 1. The electric heating elements 17 are clearly shown and are spaced apart from each other by the spacing arrangements 15.

[0074] A cross-sectional view along line A-A of the detailed part of the hybrid heater 1 of Fig. 2 is shown in Fig. 4. Inside the distribution arrangement 3, of which is shown the first wall 9 that delimits the first distribution chamber 7, are six electric heating elements 17 provided around the second distribution chamber 31 having wall 32 that is centred in the middle of the first distribution chamber 7.

[0075] Fig. 5 shows a detail of part of an electric heating element 17 that has a curved end (left-hand side) of one of the electric heating elements 17 of the electric heating arrangement 13 of Fig. 3. A cross-sectional view along line B-B of the electric heating arrangement of Fig. 3 is shown in Fig. 6. It clearly shows that the six electric heating elements 17 are spaced apart from each other by the spacing arrangement 15. The space in the centre of the spacing arrangement 15 leaves sufficient room for the second distribution chamber 31.

[0076] An isometric view of part of the second distribution chamber 31 is shown in Fig. 7 and shows that the wall 32 is provided with a plurality of distribution openings 33.

[0077] In Fig. 8 is shown a cross-sectional view in the longitudinal direction L of a detailed part of the hybrid heater 1 of Fig. 1 and illustrates the orientation of outlet openings 11 with respect to the distribution openings 33. In the respective view of Fig. 8, the outlet openings 11 of the distribution arrangement 3 are facing downwards, whereas the distribution openings 33 of the second distribution chamber 31 are facing upwards. Thus, the distribution openings 33 and the outlet openings 11 are displaced such that seen in a radial direction, perpendicular to the longitudinal direction, the distribution openings 33 and the outlet openings 11 are free from overlap.

[0078] From Fig. 8 it becomes obvious that the distribution openings 33 and the outlet openings 11 are displaced in a tangential direction about a virtual central axis A of the second distribution chamber 31 , extending in the longitudinal direction L of the hybrid heater 1 , displaced in the tangential direction about an angle in the range of 90 degrees - 180 degrees.

[0079] It becomes also obvious from Fig. 8 that a plurality of the distribution openings 33 and the outlet openings 11 are displaced in the longitudinal direction L of the heater 1 , wherein the plurality of distribution openings 33 and the plurality of outlet openings 11 are displaced such that the plurality of distribution openings 33 and the plurality of outlet openings 11 are free from overlap.

[0080] Fig. 9 shows a schematic representation of the oven 50 according to the second aspect of the present disclosure comprising three hybrid heaters 1 according to the first aspect of the present disclosure. The oven 50 comprises a control arrangement 51 arranged for controlling the flow of the mixture of the fuel gas F and the oxidant gas O to the hybrid heater 1 , and electrical power provided to the electric heating arrangement 13 arranged for heating gas distributed in the first distribution chamber 7. Logically, the control arrangement 51 may also be arranged for controlling the flow of fuel gas F to the hybrid heater 1 or the flow of an oxidant gas O to the hybrid heater 1.

[0081] In Fig. 9, the control arrangement 51 is further arranged for controlling electrical power provided to the ignition arrangement 35 for igniting the mixture of gas originating from the outlet opening 11.

[0082] A method 100 according to the third aspect of the present disclosure for operating a hybrid heater 1 according to the first aspect of the present disclosure is shown in Fig. 10. The method 100 comprises the steps of providing 101 the oxidant gas O, via the receiving opening 5, to the hybrid heater 1 ; providing 110 electrical power to the electric heating arrangement 13 for heating the oxidant gas O provided, via the receiving opening 5, to the hybrid heater 1 ; terminating 120 the step of providing 110 electrical power to the electric heating arrangement 13 for allowing the electric heating arrangement 13 to cool down; and terminating 131 the step of providing 101 the oxidant gas O, via the receiving opening 5, to the hybrid heater 1.

[0083] The step of terminating 131 the step of providing 101 the oxidant gas O is executed for a first predetermined period of time after the step of terminating 120 the step of providing 110 electrical power, wherein the first predetermined period of time is in the range of 3 to 5 minutes.

[0084] The method 100 further comprises the steps of providing 103 the fuel gas F, via the receiving opening 5, to the hybrid heater 1 ; igniting 105, by the ignition arrangement 35, the mixture of the fuel gas F and the oxidant gas O; terminating 130 the step of providing 103 the fuel gas F, via the receiving opening 5, to the hybrid heater 1 ; wherein the step of terminating 131 the step of providing 101 the oxidant gas O, via the receiving opening 5, to the hybrid heater 1 is executed after the step of terminating 130 the step of providing 103 the fuel gas F, via the receiving opening 5, to the hybrid heater 1 .

[0085] In the method 100 as shown in Fig. 10, the step of terminating 131 the step of providing 101 the oxidant gas O, via the receiving opening 5, to the hybrid heater 1 is executed after a second predetermined period of time after the step of terminating 130 the step of providing 103 the fuel gas F, via the receiving opening 5, to the hybrid heater 1 , wherein the second predetermined period of time corresponds to a time range wherein the first distribution chamber 7 and the second distribution chamber 31 are free from the fuel gas F.

[0086] As mentioned already, the steps of the method 100 may be executed in a different order than as shown in Fig. 10.

[0087] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the present disclosure, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single unit or component may fulfil the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope thereof.

[0088] The foregoing description provides embodiments of the present disclosure by way of example only. The scope of the present disclosure is defined by the appended claims. One or more of the objects of the present disclosure are achieved by the appended claims.

Claims

CLAIMS1. A hybrid heater (1) for heating an oven (50), preferably an oven such as a bread or confectionary oven, the hybrid heater (1) comprising: a distribution arrangement (3), extending over a length in a longitudinal direction (L) of the hybrid heater (1), comprising a receiving opening (5) arranged for receiving a fuel gas (F) and an oxidant gas (O), such as air, or a mixture of gas thereof, and a first distribution chamber (7) arranged for distributing the fuel gas (F) and the oxidant gas (O), or the mixture of gas thereof over a length of the hybrid heater (1) in the longitudinal direction (L) of the hybrid heater (1), wherein a first wall (9) of the distribution arrangement (3) delimiting the first distribution chamber (7) is provided with an outlet opening (11), preferably a plurality of outlet openings, for allowing the fuel gas (F) and the oxidant gas (O), or the mixture of gas thereof to exit the distribution arrangement (3); an electric heating arrangement (13), provided in the first distribution chamber (7), arranged for heating gas distributed in the first distribution chamber (7), wherein the electric heating arrangement (13) extends over a length of the first distribution chamber (7) in the longitudinal direction (L) of the hybrid heater (1).

2. The hybrid heater (1) according to claim 1 , wherein the first distribution chamber (7) is further arranged for distributing the fuel gas (F) and the oxidant gas (O), or the mixture thereof over the length of the distribution arrangement (3).

3. The hybrid heater (1) according to claim 1 or 2, wherein the electric heating arrangement (13) is arranged for maintaining a temperature of the mixture of gas below the ignition temperature of the mixture of gas.

4. The hybrid heater (1) according to any one of the preceding claims, wherein the distribution chamber (7) is provided with a plurality of outlet openings.

5. The hybrid heater (1) according to any one of the preceding claims, wherein the hybrid heater (1) further comprises a spacing arrangement (15), provided in the firstdistribution chamber (7), arranged for spacing the electric heating arrangement (13) apart from the first wall (9) at a predetermined distance.

6. The hybrid heater (1) according to claim 5, wherein the electric heating arrangement (13) comprises a plurality of electric heating elements (17) and wherein the spacing arrangement (15) is further arranged for spacing the plurality of electric heating elements (17) apart from each other at a predetermined distance over a length of the plurality of electric heating elements (17) in the longitudinal direction (L) of the hybrid heater (1).

7. The hybrid heater (1) according to any one of the preceding claims, wherein the receiving opening (5) is provided at a first end part (19) of the first distribution chamber (7) and wherein a second end part (21) of the first distribution chamber (7), opposite to the first end part (19), is closed.

8. The hybrid heater (1) according to any one of the preceding claims, wherein the hybrid heater (1) further comprises: an inlet arrangement (23, 25) arranged for receiving the fuel gas (F) and the oxidant gas (O), or the mixture of gas thereof; a mixture chamber (27), in fluid communication with the inlet arrangement (23, 25), arranged for mixing the fuel gas (F) and the oxidant gas (O); an outlet arrangement (29), in fluid communication with the mixture chamber (27), arranged for providing the fuel gas (F) and the oxidant gas (O), or the mixture of gas thereof to the distribution arrangement (3).

9. The hybrid heater (1) according to any one of the preceding claims, wherein the distribution arrangement (3) further comprises a second distribution chamber (31), provided, at least partly, inside the first distribution chamber (7) and extending over a length of the first distribution chamber (7) in the longitudinal direction (L) of the hybrid heater (1), wherein a wall (32) of the second distribution chamber (31) is provided with a distribution opening (33), preferably a plurality of distribution openings, and the second distribution chamber (31) is in fluid communication, via the distribution opening (33), with the first distribution chamber (7).

10. The hybrid heater (1) according to claim 9, wherein the first distribution chamber (7) is arranged for receiving the fuel gas (F) and the oxidant gas (O), or the mixture of gas thereof via the distribution opening (33), from the receiving opening (5).

11. The hybrid heater (1) according to claim 9 or 10, wherein the distribution opening (33) and the outlet opening (11) are displaced such that seen in a radial direction, perpendicular to the longitudinal direction, the distribution opening (33) and the outlet opening (11) are free from overlap, preferably wherein the plurality of distribution openings (33) and the plurality of outlet openings (11) are displaced such that seen in the radial direction the plurality of distribution openings (33) and the plurality of outlet openings (11) are free from overlap.

12. The hybrid heater (1) according to any one of the claims 9 to 11 , wherein the distribution opening (33) and the outlet opening (11) are displaced in a tangential direction about a virtual central axis (A) of the second distribution chamber (31), extending in the longitudinal direction (L) of the hybrid heater (1), preferably displaced in the tangential direction about an angle in the range of 10 degrees - 180 degrees, more preferably in the range of 90 degrees - 180 degrees, preferably wherein the plurality of distribution openings (33) and the plurality of outlet openings (11) are displaced in a tangential direction about a virtual central axis (A) of the second distribution chamber (31), extending in the longitudinal direction (L) of the hybrid heater (1), preferably displaced in the tangential direction about an angle in the range of 10 degrees - 180 degrees, more preferably in the range of 90 degrees - 180 degrees.

13. The hybrid heater (1) according to any one of the claims 9 to 12, wherein the distribution opening (33) and the outlet opening (11) are displaced in the longitudinal direction (L) of the hybrid heater (1), preferably wherein the distribution opening (33) and the outlet opening (11) are displaced in the longitudinal direction (L) of the hybrid heater (1) such that the distribution opening (33) and the outlet opening (11) are free from overlap, preferably wherein the plurality of distribution openings (33) and the plurality of outlet openings (11) are displaced such that the plurality of distribution openings (33) and the plurality of outlet openings (11) are free from overlap.

14. The hybrid heater (1) according to any one of the preceding claims, wherein the hybrid heater (1) further comprises: an ignition arrangement (35) arranged for igniting gas, preferably the mixture of gas, originating from the outlet opening (11).

15. An oven (50), preferably a bread oven, comprising a hybrid heater (1) according to any one of the preceding claims.

16. The oven (50) according to claim 15, wherein the oven (50) comprises a control arrangement (51) arranged for controlling at least one of: a flow of the fuel gas (F) to the hybrid heater (1); a flow of the oxidant gas (O), such as air, to the hybrid heater (1); a flow of the mixture of the fuel gas (F) and the oxidant gas (O) to the hybrid heater (1); electrical power provided to the electric heating arrangement (13) arranged for heating gas distributed in the first distribution chamber (7).

17. The oven (50) according to claim 15 or 16, using the hybrid heater (1) according to claim 14, wherein the control arrangement (51) is further arranged for controlling electrical power provided to the ignition arrangement (35) for igniting the mixture of gas originating from the outlet opening (11).

18. A method (100) for operating a hybrid heater (1) according to any one of the preceding claims 1 to 14, wherein the method (100) comprises at least one of the steps of: providing (101) the oxidant gas (O), via the receiving opening (5), to the hybrid heater (1); providing (110) electrical power to the electric heating arrangement (13) for heating the oxidant gas (O) provided, via the receiving opening (5), to the hybrid heater (1).

19. The method (100) according to claim 18, wherein the method (100) further comprises at least one of the steps of:terminating (120) the step of providing (110) electrical power to the electric heating arrangement (13) for allowing the electric heating arrangement (13) to cool down; terminating (131) the step of providing (101) the oxidant gas (O), via the receiving opening (5), to the hybrid heater (1).

20. The method (100) according to claim 19, wherein the step of terminating (131) the step of providing (101) the oxidant gas (O) is executed for a first predetermined period of time after the step of terminating (120) the step of providing (110) electrical power, preferably wherein the first predetermined period of time is in the range of 3 to 5 minutes.

21. The method (100) according to any one of the claims 18 to 20, using the hybrid heater (1) according to claim 11 , wherein the method (100) comprises the steps of: providing (103) the fuel gas (F), via the receiving opening (5), to the hybrid heater (1); igniting (105), by the ignition arrangement (35), the mixture of the fuel gas (F) and the oxidant gas (O); terminating (130) the step of providing (103) the fuel gas (F), via the receiving opening (5), to the hybrid heater (1); wherein the step of terminating (131) the step of providing (101) the oxidant gas (O), via the receiving opening (5), to the hybrid heater (1) is executed after the step of terminating (130) the step of providing (103) the fuel gas (F), via the receiving opening (5), to the hybrid heater (1).

22. The method (100) according to claim 21 , wherein the step of terminating (131) the step of providing (101) the oxidant gas (O), via the receiving opening (5), to the hybrid heater (1) is executed after a second predetermined period of time after the step of terminating (130) the step of providing (103) the fuel gas (F), via the receiving opening (5), to the hybrid heater (1), preferably wherein the second predetermined period of time corresponds to a time range wherein the first distribution chamber (7), and if present, the second distribution chamber (31) are free from the fuel gas (F).

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