Tempering furnace and method for assembling tempering furnace

Abstract

A tempering furnace (100) for glass sheets and a method for assembling the same. The furnace comprises a first furnace part (1) and a second furnace part (2) which are sequentially connected along the longitudinal direction (X) of the furnace. Each furnace part (1, 2) comprises distribution channels (4a, 4b) arranged in the longitudinal direction (X) of the furnace for distributing air to the blower housing (5). The first furnace part (1) has a blower (7) that pressurizes air drawn in from the tempering furnace and supplies it to the distribution passage (4a) of the first furnace part (1). The distribution channel (4a) of the first furnace part is connected to the distribution channel (4b) of the second furnace part for guiding air from the blower (7) to the distribution channel (4b) of the second furnace part.

Description

Technical Field

[0001] The invention relates to a tempering furnace equipped with convection heating means for glass sheets. The invention also relates to a method for assembling a tempering furnace using convection heating. Background Art

[0002] The dimensions of tempering furnaces for glass sheets are so large that they must be shipped or transported in several furnace sections or modules. These furnace sections are then connected to each other in sequence to complete the furnace. Each furnace section is provided with a convection heating device comprising a blower and a flow channel for blowing air into the furnace section to temper or heat the glass sheets therein. The problem is that the cost of said modular furnaces is high. Summary of the invention

[0003] From a first aspect, a tempering furnace for glass sheets can be provided, comprising a first furnace part and a second furnace part connected sequentially one after another in the longitudinal direction of the furnace, each of the furnace parts comprising a distribution channel arranged in the longitudinal direction of the furnace for distributing air to an air supply hood having an air supply opening, from which hot air is discharged as a jet towards the glass sheet, wherein the first furnace part is provided with an air supply fan which pressurizes air sucked from the tempering furnace and supplies the air to the distribution channel of the first furnace part, and wherein the distribution channel of the first furnace part is connected to the distribution channel of the second furnace part for guiding air from the air supply fan to the distribution channel of the second furnace part.

[0004] Thus, a tempering furnace can be realized, which is simple in construction and has low costs despite its modular structure. This low-cost structure is based on the surprising discovery that if the distribution channels of consecutive furnace sections are connected to each other, some or even most of the furnace sections can be free of blowers and electrical components such as motors, frequency converters and igniters. In particular, the costs of blowers that are subjected to high temperatures (about 700° C.) are high. The costs of blowers and their electrical components increase with the size of the blowers, but they increase even more with the increasing number of blowers arranged in the tempering furnace. In addition, the installation costs of the convection heating device decrease approximately in proportion to the number of blowers. In addition, due to the reduced number of components in the tempering furnace, the maintenance costs are reduced.

[0005] Viewed from another aspect, there may be provided a method for assembling a tempering furnace according to the first aspect, the method comprising:

[0006] providing at least two furnace sections,

[0007] connecting the at least two furnace parts one after the other in the longitudinal direction of the furnace,

[0008] The connecting comprises connecting the distribution channels of the at least two oven parts to each other to supply convective heating air from one of the at least two oven parts to the other of the at least two oven parts.

[0009] As a result, despite the modular construction of the tempering furnace, a simple and cost-effective method of assembling the tempering furnace can be achieved.

[0010] The device and the method are characterized by what is stated in the independent claims. Some other embodiments are characterized by what is stated in the other claims. Embodiments of the invention are also disclosed in the description and drawings of the present patent application. The inventive content of the present patent application may also be defined in a manner different from that defined in the following claims. The inventive content may also be formed by several separate inventions, in particular if the invention is examined in terms of expressed or implicit subtasks or in view of the benefits or groups of benefits obtained. Some definitions contained in the claims may be unnecessary in view of separate inventive concepts. Features of different embodiments of the invention may be applied to other embodiments within the scope of the basic inventive concept.

[0011] Various embodiments of the first aspect may include at least one feature from the following paragraphs:

[0012] In one embodiment, the distribution channel of the first oven part is connected to the distribution channel of the second oven part by means of a separate connector element.

[0013] An advantage is that a very gas-tight connection of the distribution channels can be provided.

[0014] In one embodiment, the separate connector element is attached to one dispensing channel but is arranged to be movable relative to the other dispensing channel.

[0015] An advantage is that dimensional changes in the distribution channel caused by temperature changes can be effectively compensated while the gas-tightness of the connection is satisfactory.

[0016] In one embodiment, the separate connector element is arranged inside at least one connected dispensing channel, preferably inside both connected dispensing channels.

[0017] An advantage is that the separate connector element does not obstruct parts or structures of the furnace close to the distribution channel.

[0018] In one embodiment, the separate connector element extends to at least one connection opening of the air supply hood and comprises a corresponding one or more openings allowing air to flow from the distribution channel to the air supply hood.

[0019] The advantage is that a free flow of air from the distribution channel to the air supply hood is ensured, while a very airtight connection of the distribution channel can be provided.

[0020] In one embodiment, the separate connector element has a less rigid structure than the first furnace part and the second furnace part at least in the longitudinal direction of the furnace.

[0021] The advantage is that dimensional changes of the distribution channels due to temperature changes can be effectively compensated, while at the same time a very gas-tight connection of the distribution channels can be provided.

[0022] In one embodiment, at least at the temperatures prevailing in use of the tempering furnace, one of the connected distribution channels is dimensioned to extend inside the other of said connected distribution channels.

[0023] An advantage is that a very simple and inexpensive structure for connecting the distribution channels can be provided.

[0024] In one embodiment, one of the connected distribution channels has a connection end, the cross section of which is enlarged, and an end of another of the connected distribution channels is arranged inside the connection end.

[0025] An advantage is that a simple and inexpensive structure for connecting the distribution channels can be provided.

[0026] In one embodiment, one of the connected distribution channels has a connection end of reduced cross-section, and one end of another of the connected distribution channels is arranged around the connection end.

[0027] An advantage is that a simple and inexpensive structure for connecting the distribution channels can be provided.

[0028] In one embodiment, the connection ends are dimensioned to provide play at room temperature, which provides space for the connected distribution channels to expand due to the temperatures prevailing in use of the tempering furnace.

[0029] The advantage is that the connection end can move or slide freely relative to another connected distribution channel when the temperature of the connection end changes. Therefore, forces and stresses that are harmful or damaging to the distribution channel can be avoided.

[0030] In one embodiment, the distribution channels of the two furnace parts are connected.

[0031] An advantage is that the costs incurred by the convection heating device can be significantly reduced due to the reduced number of blowers.

[0032] In one embodiment, the distribution channels of at least three furnace sections are connected.

[0033] An advantage is that the cost of a modular furnace with a greater length can be reduced due to the reduced number of blowers.

[0034] In one embodiment, the distribution channels of at least three furnace sections are connected, and a first furnace section comprising a blower is arranged between two furnace sections.

[0035] The advantage is that a uniform air flow can be achieved over the entire length of the furnace.

[0036] In one embodiment, the distribution channel is attached to the respective furnace part from its middle part and wherein the ends of the distribution channel are free to move due to thermal expansion.

[0037] An advantage is that structural stresses in the furnace parts caused by thermal expansion of the distribution channel can be minimized or even eliminated.

[0038] In one embodiment, the tempering furnace comprises distribution channels on both sides of the furnace, and the blowers are arranged to supply the distribution channels on both sides of the furnace.

[0039] The advantage is that a high air supply volume can be achieved in relation to investment cost.

[0040] In one embodiment, a tempering furnace comprises a glass sheet conveyor, wherein the distribution channels, the air supply hoods and the air supply openings are arranged for heating glass sheets arranged on the glass sheet conveyor by air jets blown towards at least one surface of the glass sheets, and wherein the furnace consists of structurally separated furnace parts connected in sequence, which are equipped with the distribution channels connected to each other, so that when the distribution channels become thermally expandable and air can flow from one distribution channel to another, the oppositely arranged connection ends of the distribution channels can be displaced relative to each other.

[0041] The advantage is that a simple, low-cost structure with high output capacity can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Some embodiments of the present disclosure are described in more detail in the accompanying drawings, wherein

[0043] Figure 1a is a schematic side view of the steps of the method for assembling a tempering furnace in two furnace sections and in partial cross section,

[0044] Figure 1b yes Figure 1a Schematic side view of a further step in the method of assembling a tempering furnace, with two furnace parts shown connected and partly in cross section,

[0045] Figure 2 is a schematic side view of a distribution channel,

[0046] Figure 3 is a schematic diagram of an independent connector element,

[0047] Figure 4 This is a schematic diagram of the details of the tempering furnace.

[0048] Figure 5 is a schematic side view of three furnace parts connected to each other,

[0049] Figure 6 is a schematic top view of another furnace,

[0050] Figure 7 is a schematic side view of another separate connector element, and

[0051] Figure 8 is a schematic side view of a third separate connector element connected between two furnace sections.

[0052] In the accompanying drawings, some embodiments are simplified for clarity. In the drawings, similar components are represented by the same reference numerals.

[0053] Reference Mark

[0054] 1. First furnace part

[0055] 2 Second furnace part

[0056] 3. The third furnace

[0057] 4a-c distribution channel

[0058] 5 Air supply hood

[0059] 6 Air supply opening

[0060] 7 Blower

[0061] 8 Individual connector components

[0062] 9 Connection opening

[0063] 10 Opening

[0064] 11Connection terminal

[0065] 12 Clearance

[0066] 13 Central

[0067] 14 Dividing Line

[0068] 15 fold

[0069] 16 connectors

[0070] 17 Sealing element

[0071] 18Conveyor

[0072] 19 Glass Plate

[0073] 20 Heating Elements

[0074] 100 times furnace

[0075] X furnace longitudinal DETAILED DESCRIPTION

[0076] Figure 1a is a schematic side view of the steps of the method for assembling a tempering furnace in two furnace sections and in partial cross section, Figure 1b yes Figure 1a Schematic side view of a further step in the method for assembling a tempering furnace with two furnaces shown partially connected and partially in cross section.

[0077] The glass sheets 19 are arranged to move in one direction or back and forth on rotating rollers (not shown) of a glass sheet conveyor 18 in a tempering or heating furnace 100 (hereinafter referred to as furnace). Then, the glass sheets are moved from the furnace 100 to a tempering cooling unit (not shown) after the furnace in succession, side by side or as a mixed glass load along a roller conveyor (not shown) at the tempering temperature.

[0078] The furnace 100 may be a roller furnace provided with a roller table. Alternatively, the furnace 100 may be based on the so-called glass flotation technology, in which the glass sheet floats supported by a thin cushion of air and only by one roller or other conveying member whose side edge contacts the conveying track.

[0079] In the furnace 100, the glass sheet is heated to a tempering temperature of typically 610 to 680° C., depending on the thickness of the glass. The temperature in the furnace 100 is typically 700° C. The heating of the glass sheet typically takes 40 seconds per millimeter of glass thickness, i.e., for example, 160 seconds for a glass thickness of 4 mm. The thickness of the glass sheet to be tempered is typically 1 mm-25 mm.

[0080] In the furnace 100, heat or thermal energy can be transferred to the glass by radiation from the furnace interior surfaces, by convection with the air, and by direct conduction from the contact points of the conveyor and the glass sheet. The furnace 100 can be provided with a heating element 20, such as a resistor. Gas burners can also be used.

[0081] The resistor is typically a rectangular element with a resistance wire wound around a ceramic core. The heating element 20 may be disposed above or below the glass sheet conveyor 18. Additionally or alternatively, the heating element 20 may be disposed above the air supply hood 5 ( Figure 4 ), and / or is connected to the blower 7, for example at its suction port.

[0082] The heating elements 20 are typically individually controlled, or they are arranged in groups of individually controlled heating elements.

[0083] In convection (or more accurately, forced convection), an air flow is directed to the surface of the glass sheet by a convection heating device. The forced convection in the furnace 100 can be directed to the upper surface of the glass sheet, the lower surface of the glass sheet, or the upper and lower surfaces of the glass sheet. To simplify the present disclosure, the drawings show embodiments in which the forced convection is directed only to the upper surface of the glass sheet.

[0084] The furnace 100 consists of at least two furnace parts. Figure 1a and 1b A first furnace section 1 and a second furnace section 2 are shown, but it should be noted that the furnace 100 may comprise three, four or even more furnace sections, even ten (10) etc., depending on the length of the furnace 100. The furnace sections are sequentially connected to each other one after the other in the longitudinal direction X of the furnace. The longitudinal direction X is the direction in which the glass sheets move in the furnace 100.

[0085] In one embodiment, all furnace sections arranged in the furnace have equal lengths, or at least substantially equal lengths, in the longitudinal direction of the furnace. In another embodiment, the furnace sections have substantially different lengths.

[0086] Each furnace section 1, 2 comprises at least one distribution channel 4a, 4b arranged in the longitudinal direction X of the furnace. Typically, the distribution channel extends over the entire length of the furnace section (parallel to the longitudinal direction X of the furnace). The cross-sectional shape of the distribution channel 4a, 4b can be slightly rounded (e.g. circular) or polygonal (e.g. quadrilateral).

[0087] The distribution channels 4a, 4b are connected to the structure of the respective furnace part 1, 2. In one embodiment, the distribution channels 4a, 4b are connected to the respective furnace part from their middle part 13, while the ends of said distribution channels are free to move due to thermal expansion.

[0088] The distribution channels 4a, 4b distribute the air to the air supply hood 5 ( Figure 4 2 ), the hot air is discharged as a jet from the air supply opening 6 towards the glass sheets arranged in the furnace. When the furnace parts 1 , 2 are connected to each other, the distribution channels 4a, 4b are connected to each other so that air can flow from one furnace part to the other furnace part, or more precisely, from one distribution channel to the other distribution channel. It should be noted that in embodiments of the furnace 100 comprising more than two furnace parts, the furnace part arranged between two other furnace parts comprises connection ends 11 at both ends of the distribution channels.

[0089] One furnace section, here the first furnace section 1, is provided with a blower 7. The blower pressurizes the air sucked from the tempering furnace and sends the air to the distribution channel 4a of the first furnace section 1. The distribution channel 4a of the first furnace section is connected to the distribution channel 4b of the second furnace section so that the air from the blower 7 can flow to the distribution channel 4b of the second furnace section and from there to the blower hood 5 and the blower opening 6 provided in the second furnace section 2. In other words, the hot air pressurized by one blower 7 can be delivered to two (or more) furnace sections and sent thereto to heat the glass.

[0090] In one embodiment, one distribution channel is dimensioned to extend inside the other distribution channel, at least when the furnace 100 is in its heating or tempering use, i.e. when the distribution channels expand due to the thermal expansion caused by the high temperatures in the furnace. It may then be the case that when the furnace is at a lower temperature, e.g. at room temperature, the distribution channel does not extend inside the other distribution channel. In another embodiment, one distribution channel is dimensioned to extend inside the other distribution channel also at room temperature. This is Figure 1a , 1b This is the case in the embodiment shown, in which the distribution channel 4a of the first furnace part extends within the distribution channel 4b of the second furnace part.

[0091] In one embodiment, for example Figure 1a , 1b As shown, one of the connected distributing channels 4 a , 4 b has a connection end 11 with an enlarged cross section, and one end of the other of the connected distributing channels 4 a , 4 b is arranged inside the enlarged connection end.

[0092] In one embodiment, the furnace 100 comprises two or more blowers 7 respectively arranged in two or more furnace sections, wherein at least one blower is arranged to deliver air in at least two furnace sections. This is a particularly useful embodiment in long furnaces.

[0093] Figure 2 is a schematic side view of the distribution channels. In one embodiment, one connected distribution channel 4a has a connection end 11 with a reduced cross-sectional size. Then, the end of the other connected distribution channel 4b (at Figure 2 In one embodiment, the diameter of the end of the further connected distribution channel 4b is enlarged, but in another embodiment, for example Figure 2 As shown, it has not been expanded.

[0094] In one embodiment, the connection end 11 is dimensioned so as to provide a play 12 between the connected distribution channels 4a, 4b at room temperature. The play 12 provides space for the connected distribution channels 4a, 4b to expand due to the temperatures prevailing in use of the furnace. In one embodiment, the play 12 is at least 20 mm at room temperature.

[0095] The cross-sectional dimensions of the connection ends 11, i.e. their dimensions perpendicular to the longitudinal direction X, are preferably chosen so that on the one hand there is as little clearance as possible in the temperatures prevailing when using a tempering furnace, in order to prevent or at least reduce air leakage, but on the other hand the clearance is large enough not to hinder the installation of the distribution channel and the connection ends can freely change their dimensions due to temperature changes. In one embodiment, at room temperature, there is a play of 1-2 mm in the cross-sectional dimensions of the connection ends 11.

[0096] In order to prevent or at least reduce the above-mentioned air leakage, one distribution channel is preferably dimensioned to extend about 20 mm or more inside the other distribution channel when the furnace 100 is in its heating or tempering use.

[0097] In one embodiment, the sealing element 17 is arranged between the connection ends of the connection. The sealing element 17 has an elastic structure that does not restrict the movement of the connection ends of the connection. The material of the sealing element 17 may include, for example, heat-resistant textile material or plant fiber (string).

[0098] Figure 3 is a schematic diagram of an individual connector element, and Figure 4 is a schematic diagram of a detail of a tempering furnace including the individual connector elements.

[0099] In one embodiment, the distribution channel 4a of the first furnace part is connected to the distribution channel 4b of the second furnace part by a separate connector element 8, i.e. by an element which is not part of the distribution channel but is attachable to one of the distribution channels 4a, 4b and is arranged to be movable relative to the other of the distribution channels 4a, 4b. For example, the separate connector element can be connected by welding or fastening means.

[0100] In one embodiment, for example Figure 4 In one embodiment, the separate connector element 8 is arranged inside two connected distribution channels 4a, 4b. In another embodiment, the separate connector element 8 is arranged inside only one distribution channel and outside the other connected distribution channel. In yet another embodiment, the separate connector element 8 is arranged outside the two connected distribution channels 4a, 4b.

[0101] In one embodiment, the separate connector element 8 arranged in / on the distribution channel extends to at least one connection opening 9, which connects the distribution channels 4a, 4b to the air supply hood 5. The separate connector element 8 then comprises one or more openings 10, which allow air to flow from the distribution channels 4a, 4b to the air supply hood 5.

[0102] In one embodiment, the opening 10 of the separate connector element 8 is larger than the connection opening 9 or has a rectangular shape in order to ensure that the separate connector element 8 does not cover or restrict the connection opening 9 at the temperatures prevailing in the use of the tempering furnace. Figure 4 In the embodiment shown, the opening 10 has a circular shape, the diameter of which is greater than the diameter of the connecting opening 9 .

[0103] Figure 5 1 is a schematic side view of three furnace parts 1, 2, 3 connected to each other. Moreover, the distribution channels 4a, 4b, 4c of at least three furnace parts are connected. In one embodiment, the first furnace part 1 including the blower 7 is arranged between the other two furnace parts 2, 3. In this embodiment, both ends of the distribution channel 4a of the first furnace part 1 are connected to another distribution channel. In another embodiment, the first furnace part 1 is arranged at one end of the furnace 100, and the other furnace parts 2, 3 are arranged only on one side thereof.

[0104] Figure 6 is a schematic top view of another furnace. In one embodiment, the furnace 100 has a distribution channel consisting of connected distribution channels of furnace parts as described in this specification. The distribution channel can be arranged, for example, on one side of the furnace.

[0105] In another embodiment, the furnace 100 comprises a plurality of complete distribution channels arranged in parallel, which are formed by connecting distribution channels 4a, 4b, 4c of the furnace parts. In one embodiment, for example Figure 6 As shown, the furnace 100 comprises two complete distribution channels, which are arranged on both sides of the furnace and are composed of connected distribution channels 4a, 4b, 4c. In one embodiment, the supply hoods 5 arranged in series and in parallel are connected to the distribution channels alternately. It should be noted that for the sake of clarity, Figure 6 Only a portion of the air supply hood is shown.

[0106] In one embodiment, for example Figure 6 As shown, the furnace 100 comprises a blower 7 in the first furnace part 1, which is arranged to supply two or more parallel arranged complete distribution channels. In another embodiment, each parallel arranged complete distribution channel is supplied by its own blower, i.e. each blower is arranged to supply only one complete distribution channel. These blowers can be arranged in the same furnace part, or in different furnace parts.

[0107] The figures show an embodiment in which the distribution channels 4a, 4b, 4c are supplied by only one blower 7. However, in some embodiments, two or even more blowers 7 are configured to supply the same distribution channel. In one embodiment, the two or more blowers are arranged in the same furnace part. In another embodiment, the two or more blowers are arranged in different furnace parts.

[0108] Figure 7 is a schematic side view of another separate connector element. In one embodiment, the separate connector element 8 has a less rigid structure than the first furnace part 1 and the second furnace part 2 connected by the separate connector element. Such a separate connector element 8 can be fixedly connected to two connected furnace parts.

[0109] In one embodiment, the individual connector element 8 comprises at least one bellow 15 which extends around the individual connector element and allows said element to shorten and lengthen in the longitudinal direction X of the furnace so that the connected distribution channels are not destroyed. The bellows may be made of a suitable metal, for example.

[0110] In another embodiment, Figure 8 As shown, the less rigid structure of the separate connector element 8 includes a joint 16 made of a flexible material, such as a textile, fabric or cloth that withstands the high temperatures of the furnace.

[0111] The present invention is not limited to the above-mentioned embodiments only, but on the contrary, many variations are possible within the scope of the inventive concept defined by the appended claims. Within the scope of the inventive concept, the properties of different embodiments and applications can be used in combination with or in place of the properties of another embodiment or application.

[0112] The drawings and the related description serve only to illustrate the idea of ​​the invention. The invention may vary in detail within the scope of the inventive concept defined in the appended claims.

Claims

1. A tempering furnace (100) for glass sheets, comprising a first furnace section (1) and a second furnace section (2) connected one behind the other in a longitudinal direction (X) of the furnace, wherein the furnace sections are configured to heat the glass sheets to a tempering temperature, Each of the oven sections (1, 2) comprises a distribution channel (4a, 4b) inside the oven section, the distribution channel being arranged in the longitudinal direction (X) of the oven for distributing air to an air supply hood (5) having an air supply opening (6) from which the hot air is discharged as a jet towards the glass sheet, The first furnace part (1) is provided with a blower (7) which pressurizes the air sucked from the tempering furnace and supplies the air to the distribution channel (4a) of the first furnace part (1), characterized in that: The distribution channel (4a) of the first furnace part is connected to the distribution channel (4b) of the second furnace part to guide air from the blower (7) to the distribution channel (4b) of the second furnace part, and At least at the temperatures that prevail in use of the tempering furnace, one of the connected distribution channels (4a, 4b) is dimensioned to extend inside the other of the connected distribution channels (4a, 4b).

2. The tempering furnace according to claim 1, wherein: One of the connected distribution channels (4a, 4b) has a connection end (11) with an increased cross section, and one end of the other of the connected distribution channels (4a, 4b) is arranged inside the connection end.

3. The tempering furnace according to claim 1 or 2, wherein: One of the connected distribution channels (4a, 4b) has a connection end (11) with a reduced cross section, and one end of the other of the connected distribution channels (4a, 4b) is arranged around the connection end.

4. The tempering furnace according to claim 2 or 3, wherein: The connection end (11) is dimensioned to provide a play (12) at room temperature which provides space for the connected distribution channels (4a, 4b) to expand due to the temperatures prevailing in use of the tempering furnace.

5. A tempering furnace according to any one of the preceding claims, wherein: The distribution channels (4a, 4b) of the two furnace parts are connected.

6. The tempering furnace according to any one of claims 1 to 4, wherein: The distribution channels (4a, 4b, 3c) of at least three furnace sections are connected.

7. The tempering furnace according to claim 6, wherein: The first furnace section (1) comprises a blower (7), which is arranged between the two furnace sections.

8. A tempering furnace according to any one of the preceding claims, wherein: The distribution channels (4a, 4b, 4c) are attached to the respective furnace parts (1, 2, 3) from their middle parts (13), and wherein the ends of the distribution channels (4a, 4b, 4c) are free to move due to thermal expansion.

9. A tempering furnace according to any one of the preceding claims, comprising distribution channels (4a, 4b, 4c) on both sides of the furnace, the blower (7) being arranged to supply the distribution channels (4a, 4b, 4c) on both sides of the furnace.

10. A tempering furnace according to any one of the preceding claims, comprising a glass sheet conveyor (18), wherein the distribution channels (4a, 4b), the air supply hoods (5) and the air supply openings (6) are arranged for heating the glass sheets by air jets supplying air towards at least one surface of a glass sheet (19) arranged on the glass sheet conveyor (18), and wherein the furnace consists of structurally separated sequentially connected furnace parts (1, 2, 3), which are equipped with the distribution channels (4a, 4b, 4c) connected to each other, so that when the distribution channels (4a, 4b, 4c) become thermally expandable and air can flow from one distribution channel to another, the oppositely arranged connection ends (11) of the distribution channels are displaceable relative to each other.

11. A method for assembling a tempering furnace (100) according to any one of the preceding claims, the method comprising: providing at least two furnace sections (1, 2, 3), connecting the at least two furnace parts one after the other in the longitudinal direction of the furnace, The connection comprises connecting the distribution channels (4a, 4b, 4c) of the at least two oven parts (1, 2, 3) to each other in order to supply convective heating air from one of the at least two oven parts (1, 2, 3) to the other of the oven parts.

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