Baking unit and bread tunnel furnace

Abstract

The invention provides a baking unit, namely a bread tunnel furnace. The baking unit comprises a first burner, a second burner, a first tube bank and a second tube bank. Wherein the first combustion engine is provided with a first combustion cylinder, the first combustion cylinder is connected with a first air distribution box and a first air return box, and the first air return box is connected with a first fan; the second combustor is provided with a second combustion cylinder, the second combustion cylinder is connected with a second air distribution box and a second air return box, and the second air return box is connected with a second fan; the first pipe row comprises a plurality of first radiant pipes, and the two ends of the first radiant pipes communicate with the first air distribution box and the first air return box correspondingly. A baking channel is formed between the second pipe row and the first pipe row. The second pipe row comprises a plurality of second radiant tubes. The two ends of each second radiant tube communicate with the second air distribution box and the second air return box correspondingly. According to the baking unit and the bread tunnel furnace, different baking temperatures can be obtained at the top and the bottom of bread, and the bread baking quality is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bread baking equipment, and in particular relates to a baking unit and a bread tunnel oven. Background Art

[0002] At present, most large-scale bread baking production lines use tunnel ovens. Their working principle is to use a continuously running high-temperature resistant conveyor belt to support the bread tray through the tunnel oven, and use the high temperature inside the tunnel oven to complete the baking process. Usually, during the bread baking process, the bottom is heated to make the inside of the bread fully cooked, and the top is heated to form a crispy surface. However, due to the constant temperature performance inside the bread tunnel oven, if the temperature and time are controlled from the perspective of bottom heating, it is easy to cause the surface of the bread to be too burnt or insufficiently crispy. If the temperature and time are controlled from the perspective of top heating, it is easy to cause the inside of the bread to be insufficiently cooked or the bread to be too dry, affecting the taste. Faced with the increasing demand for high-quality bread, there is an urgent need to develop a bread tunnel oven that can solve the above problems. Summary of the invention

[0003] The embodiments of the present invention provide a baking unit and a bread tunnel oven, aiming to improve the bread baking quality of the bread tunnel oven.

[0004] To achieve the above object, the technical solution adopted by the present invention is: in a first aspect, a baking unit is provided, comprising: The first burner has a first combustion tube, the first combustion tube is connected to a first air distribution box and a first return air box, and the first return air box is connected to a first fan; The second burner has a second combustion tube, which is located on the side of the first burner and is connected to a second air distribution box and a second air return box, and the second air return box is connected to a second fan; A first tube row includes a plurality of first radiation tubes distributed below the first burner and the second burner, wherein two ends of the first radiation tubes are respectively connected to the first air distribution box and the first air return box; The second tube row is located directly below the first tube row and forms a baking channel suitable for the conveyor belt to pass through between the second tube row and the first tube row; the second tube row includes a plurality of second radiation tubes, and both ends of the second radiation tubes are respectively connected to the second air distribution box and the second return air box.

[0005] In combination with the first aspect, in a possible implementation, the first air distribution box includes a first straight cylinder air duct and a first air distribution air duct; wherein the first straight cylinder air duct is connected to the first combustion cylinder and extends along the axial direction of the first combustion cylinder; the first air distribution air duct is connected to the same end of each first radiation tube and is connected to the extended end of the first straight cylinder air duct; The second air distribution box includes a second straight air duct and a second air distribution duct; wherein the second straight air duct is connected to the second combustion tube and extends along the axial direction of the second combustion tube; the second air distribution duct is located directly below the first air distribution duct and is connected to the same end of each second radiation tube, and the second air distribution duct is bent in the lateral direction of the conveyor mesh belt and connected to the extended end of the second straight air duct.

[0006] In some embodiments, the air outlet of the first fan is connected to the first return air duct, which is connected to the first combustion tube; the air outlet of the second fan is connected to the second return air duct, which is connected to the second combustion tube; the first return air box includes a first return air duct corresponding to the first air distribution duct, and each first radiation tube is connected to the first return air duct; the second return air box includes a second return air duct corresponding to the second air distribution duct, and each second radiation tube is connected to the second return air duct.

[0007] Exemplarily, a first air regulating assembly is provided on the side wall of the first return air box, and each first radiation tube is connected to the first return air box through the first air regulating assembly, and the first air regulating assembly is used to individually and synchronously adjust the ventilation volume of each first radiation tube; a second air regulating assembly is provided on the side wall of the second return air box, and each second radiation tube is connected to the second return air box through the second air regulating assembly, and the second air regulating assembly is used to individually and synchronously adjust the ventilation volume of each second radiation tube.

[0008] For example, the first air regulating component and the second air regulating component have the same structure; wherein, the first air regulating component includes a plurality of independent air regulating units, and a synchronous regulating mechanism respectively connected to each independent air regulating unit; each independent air regulating unit is respectively connected to each first radiation tube, and is respectively used to independently adjust the ventilation volume of each first radiation tube; the synchronous regulating mechanism is used to drive each independent air regulating unit to move synchronously.

[0009] In a possible implementation, the independent air conditioning unit includes: A fixed sleeve is fixedly connected to the side wall of the first return air box and communicated with the first return air box, a valve plate is arranged in the fixed sleeve, and the valve plate has a plurality of valve holes distributed at intervals along the circumference of the fixed sleeve; A rotating sleeve, one end of which is rotatably connected to the fixed sleeve, and the other end of which is rotatably matched with the first radiation tube. A sealing plate is provided inside the rotating sleeve, and the sealing plate has a plurality of air holes spaced apart along the circumference of the rotating sleeve. Among them, when the rotating sleeve rotates, the sealing plate can form a fully open state in which all air holes are aligned with all valve holes, a fully closed state in which all air holes are staggered with all valve holes, and a half-open state between the fully open state and the fully closed state.

[0010] In some embodiments, the synchronization adjustment mechanism includes: A plurality of worm wheels are respectively sleeved on the outer circumference of each rotating sleeve and rotated with the rotating sleeve. The side wall of each worm wheel is provided with a locking piece, which is used to lock the relative rotational freedom of the worm wheel and the rotating sleeve; The rotating shaft is rotatably connected to the side wall of the first return air box. The rotating shaft has a plurality of worm sections that are connected in sequence, and each worm section is meshed with each worm wheel.

[0011] Exemplarily, a positioning plate is provided on the outer periphery of the rotating sleeve, a circular arc hole is provided on the positioning plate, and a locking member passes through the circular arc hole and is screwed to the worm gear; a shifting rod is provided on the positioning plate.

[0012] For example, a first annular groove is provided at one end of the rotating sleeve, and the end of the fixed sleeve is sealed and inserted in the first annular groove and rotatably cooperates with the first annular groove; a second annular groove is provided at the other end of the rotating sleeve, and one end of the first radiation tube is sealed and inserted in the second annular groove and rotatably cooperates with the second annular groove.

[0013] The beneficial effect of the baking unit provided by the present invention is that compared with the prior art, in the baking unit of the present invention, the first burner can heat the air flowing through the first combustion tube, and the first fan is used to establish an air circulation route between the first return air box, the first combustion tube, the first air distribution box, and the first tube row, so that each first radiation tube performs heat radiation baking on the top of the bread placed on the conveyor mesh belt and passing through the baking channel; the second burner heats the air flowing through the second combustion tube, and the second fan is used to establish an air circulation route between the second return air box, the second combustion tube, the second air distribution box, and the second tube row, so that each second radiation tube performs heat radiation baking on the bottom of the bread placed on the conveyor mesh belt; because the first burner and the second burner can heat the air flowing in the first radiation tube and the second radiation tube respectively, so that the first radiation tube and the second radiation tube obtain different temperatures, the top and bottom of the bread can respectively obtain different baking temperatures, so that the top of the bread obtains the required baking temperature to ensure the surface color and crispness, and the bottom of the bread obtains the required baking temperature to avoid the problem of undercooked or overheated dry hardness inside the bread, thereby improving the bread baking quality of the bread tunnel furnace.

[0014] In a second aspect, an embodiment of the present invention further provides a bread tunnel oven, comprising at least one of the above-mentioned baking units.

[0015] The beneficial effect of the bread tunnel oven provided by the present invention is that compared with the prior art, the bread tunnel oven of the present invention adopts the above-mentioned baking unit, and the first burner and the second burner can heat the air circulating in the first radiation tube and the second radiation tube respectively, so that the first radiation tube and the second radiation tube obtain different temperatures, so that the top of the bread obtains the required baking temperature to ensure the surface color and crispness, and the bottom of the bread obtains the required baking temperature to avoid the problem of undercookedness or overheating and hardness inside the bread, thereby improving the bread baking quality of the bread tunnel oven. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the three-dimensional structure of a baking unit provided in an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the local enlarged structure at point A in the middle; Figure 3 A schematic diagram of the three-dimensional structure of the first burner and the first tube row used in an embodiment of the present invention; Figure 4 A schematic diagram of the three-dimensional structure of the second burner and the second tube row used in the embodiment of the present invention; Figure 5 A schematic diagram of the three-dimensional structure of a first air regulating assembly used in an embodiment of the present invention; Figure 6 A schematic cross-sectional view of the first air regulating assembly used in an embodiment of the present invention; Figure 7 A schematic diagram of the three-dimensional structure of a rotating sleeve used in an embodiment of the present invention; Figure 8 A schematic diagram of the three-dimensional structure of the rotating sleeve used in the embodiment of the present invention from another angle; Fig. 9 It is a schematic diagram of the three-dimensional structure of the fixing sleeve used in the embodiment of the present invention.

[0017] In the figure: 10, first burner; 11, first combustion tube; 12, first air distribution box; 121, first straight tube air duct; 122, first air distribution air duct; 13, first return air box; 131, first return air duct; 14, first fan; 15, first return air duct; 20, second burner; 21, second combustion tube; 22, second air distribution box; 221, second straight tube air duct; 222, second air distribution air duct; 23, second return air box; 231, second return air duct; 24, second fan; 25, second return air duct; 30, first tube row; 300, first radiant tube; 40, second tube row; 400, second radiant tube; 50, first air adjustment component; 51, independent air adjustment unit; 511, fixed sleeve; 5111, valve plate; 5112, valve hole; 512, rotating sleeve; 5121, sealing plate; 5122, air hole; 5123, first ring groove; 5124, second ring groove; 5125, high temperature resistant sealing ring; 513, positioning plate; 5131, arc hole; 5132, lever; 52, synchronous adjustment mechanism; 521, worm gear; 5211, locking piece; 522, rotating shaft; 5221, worm; 60, second air adjustment component; 70, conveyor belt. DETAILED DESCRIPTION

[0018] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] It should be noted that when an element is referred to as being "disposed on" or "connected to" another element, it may be directly on the other element or indirectly on the other element. It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "back", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" and "several" is two or more, unless otherwise clearly and specifically defined.

[0020] Please also read Figures 1 to 9The baking unit provided by the present invention is now described. The baking unit comprises a first burner 10, a second burner 20, a first pipe row 30 and a second pipe row 40; wherein the first burner 10 comprises a first combustion tube 11, the first combustion tube 11 is connected to a first air distribution box 12 and a first return air box 13, and the first return air box 13 is connected to a first blower 14; the second burner 20 comprises a second combustion tube 21, the second combustion tube 21 is located at the side of the first burner 10 and is connected to a second air distribution box 22 and a second return air box 23, and the second return air box 23 is connected to a second blower 14; Machine 24; the first tube row 30 includes a plurality of first radiation tubes 300 distributed below the first burner 10 and the second burner 20, and the two ends of the first radiation tubes 300 are respectively connected to the first air distribution box 12 and the first return air box 13; the second tube row 40 is located directly below the first tube row 30, and a baking channel suitable for the conveyor mesh belt 70 to pass through is formed between the second tube row 40 and the first tube row 30; the second tube row 40 includes a plurality of second radiation tubes 400, and the two ends of the second radiation tubes 400 are respectively connected to the second air distribution box 22 and the second return air box 23.

[0021] It should be noted that the air blown into the first combustion tube 11 by the first fan 14 acquires a high temperature and enters the first air distribution box 12, and evenly enters the first radiation tubes 300 of the first tube row 30 through the first air distribution box 12, and then enters the first return air box 13, and returns to the first combustion tube 11 under the suction action of the first fan 14, thereby forming an air circulation route, so that the first radiation tubes 300 maintain a stable baking temperature to perform radiation baking on the top of the bread in the bread tray placed on the conveyor mesh belt 70; the air blown into the second combustion tube 21 by the second fan 24 acquires a high temperature and enters the second air distribution box 22, and evenly enters the second radiation tubes 400 of the second tube row 40 through the second air distribution box 22, and then After that, it enters the second return air box 23 and returns to the second combustion tube 21 under the suction action of the second fan 24, thereby also forming an air circulation flow route, so as to ensure the stable baking temperature of each second radiation tube 400, so that the second radiation tube 400 radiates and bakes the bottom of the bread in the bread tray placed on the conveyor mesh belt 70; because the power of the first burner 10 and the second burner 20 can be controlled to make the first radiation tube 300 and the second radiation tube 400 obtain corresponding temperatures, so that the top of the bread can be subjected to a higher radiation temperature to form a crispy surface, and the bottom of the bread can obtain a lower radiation temperature to ensure the softness of the bread, so as to avoid the bottom temperature being too high, causing the bread to be dry and hard and affect the taste.

[0022] It should also be explained that in the present embodiment, the first burner 10 and the second burner 20 are both arranged above the first tube row 30. This can, on the one hand, prevent the first combustion tube 11 and the second combustion tube 21, which are the parts with the highest temperature, from baking the bottom of the bread and causing the bread to become dry and hard. On the other hand, the high temperature of the first combustion tube 11 and the second combustion tube 21 can be used to make the top of the bread reach a higher temperature than the bottom, thereby making full use of the thermal energy. In addition, the first burner 10 and the second burner 20 can be installed side by side, thereby improving the compactness of the overall structure.

[0023] It should be noted that, since the temperature will gradually decrease during the air circulation process, the first tube row 30 and the second tube row 40 in this embodiment respectively heat the air through the first burner 10 and the second burner 20, so that two independent air circulation routes can be formed for the top and bottom of the bread, thereby shortening the length of the air circulation route, thereby avoiding the air circulation route being too long, resulting in a large temperature difference at different axial positions of the first radiation tube 300 and the second radiation tube 400, thereby affecting the stability of the bread baking temperature.

[0024] Compared with the prior art, the baking unit provided in this embodiment is capable of heating the air flowing through the first combustion tube 11 by the first burner 10, and establishing an air circulation route among the first return air box 13, the first combustion tube 11, the first air distribution box 12, and the first tube row 30 by the first fan 14, so that each first radiation tube 300 performs heat radiation baking on the top of the bread placed on the conveyor mesh belt 70 and passing through the baking channel; the second burner 20 heats the air flowing through the second combustion tube 21, and establishing an air circulation route among the second return air box 23, the second combustion tube 21, the second air distribution box 22, and the second tube row 40 by the second fan 24, so that each The second radiation tube 400 performs thermal radiation baking on the bottom of the bread placed on the conveyor belt 70; since the first burner 10 and the second burner 20 can heat the air flowing in the first radiation tube 300 and the second radiation tube 400 respectively, so that the first radiation tube 300 and the second radiation tube 400 obtain different temperatures, the top and bottom of the bread can obtain different baking temperatures respectively, so that the top of the bread can obtain the required baking temperature to ensure the surface color and crispness, and the bottom of the bread can obtain the required baking temperature to avoid the problem of undercookedness or overheating and hardness inside the bread, thereby improving the bread baking quality of the bread tunnel oven.

[0025] In some embodiments, see Figure 1 and Figure 3The first air distribution box 12 includes a first straight cylinder air duct 121 and a first air distribution duct 122; wherein the first straight cylinder air duct 121 is connected to the first combustion cylinder 11 and extends along the axial direction of the first combustion cylinder 11; the first air distribution duct 122 is connected to the same end of each first radiation tube 300, and is connected to the extended end of the first straight cylinder air duct 121.

[0026] Since the high-temperature radiation baking source on the top of the bread is the first tube row 30, the first straight cylinder air duct 121 is set to ensure that the high-temperature air heated by the first combustion tube 11 quickly passes through the first straight cylinder air duct 121 into the first air distribution duct 122, and then enters each first radiation tube 300, thereby avoiding the high-temperature air from staying in the first straight cylinder air duct 121 for too long, which is beneficial to reducing heat loss; the first air distribution duct 122 adopts a U-shaped bending structure, which can be connected to the first straight cylinder air duct 121 and then extend along the arrangement direction of the first radiation tube 300, thereby realizing the connection between the first air distribution duct 122 and each first radiation tube 300, and the structure is simple and compact.

[0027] See 1 and Figure 4 The second air distribution box 22 includes a second straight air duct 221 and a second air distribution duct 222; wherein the second straight air duct 221 is connected to the second combustion tube 21 and extends along the axial direction of the second combustion tube 21; the second air distribution duct 222 is located directly below the first air distribution duct 122 and is connected to the same end of each second radiation tube 400, and the second air distribution duct 222 is bent in the lateral direction of the conveyor mesh belt 70 and is connected to the extended end of the second straight air duct 221.

[0028] Since the high-temperature radiation baking source at the bottom of the bread top is the second tube row 40, a second straight-cylinder air duct 221 is provided to ensure that the high-temperature air heated by the second combustion tube 21 quickly passes through the second straight-cylinder air duct 221 into the second air distribution duct 222, and then enters each second radiation tube 400, thereby avoiding the high-temperature air from staying in the second straight-cylinder air duct 221 for too long, which is beneficial to reducing heat loss; the second air distribution duct 222 adopts a U-shaped curved structure, which can be connected to the second straight-cylinder air duct 221 and then go around from the side of the conveyor mesh belt 70 to the bottom of the conveyor mesh belt 70 and extend along the arrangement direction of the second radiation tube 400, thereby realizing the connection between the second air distribution duct 222 and each second radiation tube 400, and the structure is simple and compact.

[0029] For some possible implementations, see Figures 1 to 4The air outlet of the first fan 14 is connected to the first return air duct 15, and the first return air duct 15 is connected to the first combustion tube 11; the air outlet of the second fan 24 is connected to the second return air duct 25, and the second return air duct 25 is connected to the second combustion tube 21; the first return air box 13 includes a first return air duct 131 corresponding to the first air distribution duct 122, and each first radiation tube 300 is connected to the first return air duct 131; the second return air box 23 includes a second return air duct 231 corresponding to the second air distribution duct 222, and each second radiation tube 400 is connected to the second return air duct 231.

[0030] The first fan 14 draws air from the first return air duct 131 to form a negative pressure in the first return air duct 131, so that the high-temperature air in the first air distribution duct 122 flows through each first radiation tube 300 to the first return air duct 131. During the circulation process, the air is radiated and baked on the top of the bread by the first radiation tube 300 and gradually cooled down. The first fan 14 draws the air with the lowered temperature from the first return air duct 131 and re-discharges it into the first combustion tube 11 through the first return air duct 15 for heating, thereby forming air circulation heating. The first return air duct 131 is used to connect the ends of each first radiation tube 300 away from the first air distribution duct 122, so the structure of the first return air duct 131 can be the same U-shaped bending structure as the first air distribution duct 122; similarly, the second return air duct 231 adopts the same U-shaped bending structure as the second air distribution duct 222 to realize the method of winding from the bottom of the conveyor mesh belt 70 to the top of the first tube row 30, so that the first fan 14 and the second fan 24 can both be located above the first tube row 30, thereby improving the compactness of the overall structure.

[0031] In some embodiments, such as Figure 2 As shown, a first air regulating assembly 50 is provided on the side wall of the first return air box 13, and each first radiation tube 300 is connected to the first return air box 13 through the first air regulating assembly 50, and the first air regulating assembly 50 is used to individually and synchronously adjust the ventilation volume of each first radiation tube 300; a second air regulating assembly 60 is provided on the side wall of the second return air box 23, and each second radiation tube 400 is connected to the second return air box 23 through the second air regulating assembly 60, and the second air regulating assembly 60 is used to individually and synchronously adjust the ventilation volume of each second radiation tube 400.

[0032] In order to ensure the consistency of bread baking temperature at different positions of the width of the conveyor belt 70, it is necessary to ensure that the air flow in each first radiation tube 300 and each second radiation tube 400 is consistent. Therefore, a first air regulating component 50 capable of individually adjusting the ventilation volume of each first radiation tube 300 and a second air regulating component 60 capable of individually adjusting the ventilation volume of each second radiation tube 400 are provided. By adjusting the first air regulating component 50, the ventilation volume of each first radiation tube 300 can be made consistent, and by adjusting the second air regulating component 60, the ventilation volume of each second radiation tube 400 can be made consistent, thereby ensuring the consistency of bread baking temperature at different positions.

[0033] In addition, when the air heating temperature remains unchanged, the baking temperature of the top of the bread is proportional to the air flow rate of the first radiation tube 300, and the baking temperature of the bottom of the bread is proportional to the air flow rate of the second radiation tube 400. The ventilation volume of each first radiation tube 300 can be synchronously adjusted by the first air regulating component 50, so as to achieve the adjustment of the baking temperature of the top of the bread. At the same time, the ventilation volume of each second radiation tube 400 can be synchronously adjusted by the second air regulating component 60, so as to achieve the adjustment of the baking temperature of the bottom of the bread, thereby meeting the baking temperature adjustment requirements of different types of bread.

[0034] Specifically, see Figure 2 , Figures 5 to 9 In this embodiment, the first air regulating assembly 50 and the second air regulating assembly 60 have the same structure; wherein, the first air regulating assembly 50 includes a plurality of independent air regulating units 51, and a synchronous regulating mechanism 52 respectively connected to each independent air regulating unit 51; each independent air regulating unit 51 is respectively connected to each first radiation tube 300, and is respectively used to independently adjust the ventilation volume of each first radiation tube 300; the synchronous regulating mechanism 52 is used to drive each independent air regulating unit 51 to move synchronously.

[0035] By adjusting each independent air regulating unit 51, the ventilation volume of each first radiation tube 300 and each second radiation tube 400 can be adjusted separately, so as to ensure that the bread baking temperature at different positions of the conveyor belt 70 is consistent; through the synchronous adjustment structure, each independent air regulating unit 51 can be driven to operate at the same time, so as to achieve the adjustment of the overall ventilation volume, and then the adjustment of the baking temperature, and the adjustment method is simple and convenient.

[0036] As a specific implementation of the independent air conditioning unit 51, please refer to Figures 5 to 9The independent air regulating unit 51 includes a fixed sleeve 511 and a rotating sleeve 512; the fixed sleeve 511 is fixedly connected to the side wall of the first return air box 13 and communicated with the first return air box 13, a valve plate 5111 is arranged in the fixed sleeve 511, and the valve plate 5111 has a plurality of valve holes 5112 distributed at intervals along the circumference of the fixed sleeve 511; one end of the rotating sleeve 512 is rotatably connected to the fixed sleeve 511, and the other end is rotatably matched with the first radiation tube 300, a sealing plate 5121 is arranged in the rotating sleeve 512, and the sealing plate 5121 has a plurality of air holes 5122 distributed at intervals along the circumference of the rotating sleeve 512; wherein, when the rotating sleeve 512 rotates, the sealing plate 5121 can form a fully open state in which all air holes 5122 are aligned with all valve holes 5112, a fully closed state in which all air holes 5122 are staggered with all valve holes 5112, and a half-open state between the fully open state and the fully closed state.

[0037] The alignment state of the sealing plate 5121 and the valve plate 5111 can be adjusted by turning the rotating sleeve 512. When all the valve holes 5112 and the air holes 5122 are aligned, the ventilation volume is the largest, and the temperature of the first radiation tube 300 will be higher; when all the valve holes 5112 and the air holes 5122 are staggered, the first radiation tube 300 can be closed, thereby reducing the width of the bread tray placed on the conveyor belt 70 during low-output operation. At this time, the first radiation tube 300 outside the bread placement area can be closed, thereby reducing heat loss and energy consumption; rotating the rotating sleeve 512 between the fully open state and the half-open state can adjust the ventilation volume of the first radiation tube 300, and then adjust the temperature of the first radiation tube 300. The adjustment method is simple and convenient.

[0038] It should be noted that the ventilation volume of the first radiation tube 300 depends on the suction negative pressure generated by the first fan 14 on the first return air box 13, so that the first return air box 13 forms a negative pressure extraction effect on each first radiation tube 300. At this time, the larger the area where the valve hole 5112 and the air hole 5122 are aligned, the larger the opening of the first radiation tube 300 is, and the larger the ventilation volume is. The purpose of setting the independent air regulating unit 51 is to balance the ventilation volume of each first radiation tube 300, to avoid the extraction force of the first return air box 13 close to the first fan 14 being higher than the extraction force at the position far from the first fan 14, thereby causing the ventilation volume difference of different first radiation tubes 300. Specifically, the opening of the first radiation tube 300 close to the first fan 14 can be appropriately reduced, and the opening of the first radiation tube 300 far from the first fan 14 can be appropriately increased. The difference in the opening of the first radiation tube 300 makes up for the difference in the negative pressure extraction force, so that the ventilation volume in each first radiation tube 300 tends to be consistent, thereby improving the consistency of bread baking temperature at different positions.

[0039] Optionally, see Figure 5 and Figure 6In this embodiment, the synchronous adjustment mechanism 52 includes a plurality of worm gears 521 and a rotating shaft 522; wherein, each worm gear 521 is respectively sleeved on the outer periphery of each rotating sleeve 512 and rotates with the rotating sleeve 512, and the side wall of each worm gear 521 is provided with a locking member 5211, and the locking member 5211 is used to lock the relative rotational freedom of the worm gear 521 and the rotating sleeve 512; the rotating shaft 522 is rotatably connected to the side wall of the first return air box 13, and the rotating shaft 522 has a plurality of worm gear sections 5221 connected in sequence, and each worm gear section 5221 is respectively meshed with each worm gear 521.

[0040] Here, the rotating shaft 522 can be rotated manually or by a driving member such as a motor. By rotating the rotating shaft 522, each worm 5221 can be used to drive each worm wheel 521 to rotate, so that the rotating sleeve 512 locked with the worm wheel 521 by the locking member 5211 rotates together with the worm wheel 521, so as to achieve synchronous adjustment of the opening of each first radiation tube 300; when it is necessary to adjust the opening of each first radiation tube 300 separately, it is only necessary to loosen the locking member 5211. At this time, the worm wheel 521 and the worm 5221 are in a meshing self-locking state, so that the rotating sleeve 512 can be rotated relative to the worm wheel 521, so that the sealing plate 5121 can be rotated relative to the valve plate 5111 to adjust the alignment area of ​​the air hole 5122 and the valve hole 5112. After the adjustment is in place, the locking member 5211 can be re-locked. The structure is simple and compact, and the adjustment method is simple and convenient.

[0041] It is important to understand that see Figure 5 In this embodiment, a positioning plate 513 is provided on the outer periphery of the rotating sleeve 512 , and a circular arc hole 5131 is provided on the positioning plate 513 . The locking member 5211 passes through the circular arc hole 5131 and is screwed to the worm gear 521 ; a lever 5132 is provided on the positioning plate 513 .

[0042] The positioning plate 513 is used to penetrate the locking member 5211 to realize the locking connection between the rotating sleeve 512 and the worm wheel 521. The locking member 5211 can be a screw. The locking member 5211 passes through the arc hole 5131 and presses the positioning plate 513 to make the worm wheel 521 drive the rotating sleeve 512 to rotate synchronously. When individual adjustment is required, it is only necessary to loosen the locking member 5211 and move the lever 5132 to make the rotating sleeve 512 rotate relative to the worm wheel 521. At this time, the locking member 5211 can slide in the arc hole 5131. After adjusting to the right position, the locking member 5211 can be directly tightened. The operation is simple and convenient.

[0043] For example, Figures 6 to 8As shown, a first annular groove 5123 is provided at one end of the rotating sleeve 512, and the end of the fixed sleeve 511 is sealed and inserted in the first annular groove 5123 and rotatably cooperates with the first annular groove 5123; a second annular groove 5124 is provided at the other end of the rotating sleeve 512, and one end of the first radiation tube 300 is sealed and inserted in the second annular groove 5124 and rotatably cooperates with the second annular groove 5124.

[0044] A high temperature resistant sealing ring 5125 such as a polytetrafluoroethylene ring may be arranged in the first annular groove 5123 to cooperate with the fixed sleeve 511 to achieve a sealed connection. A high temperature resistant sealing ring 5125 such as a polytetrafluoroethylene ring may also be arranged in the second annular groove 5124 to cooperate with the end of the first radiation tube 300 to achieve a sealed connection. At the same time, the rotating sleeve 512 can rotate relative to the fixed sleeve 511 and the first radiation tube 300, so as to realize the rotation of the sealing plate 5121 relative to the valve plate 5111 to adjust the ventilation volume of the first radiation tube 300, thereby avoiding air leakage at the connection position between the rotating sleeve 512, the fixed sleeve 511 and the first radiation tube 300.

[0045] Based on the same inventive concept, Figures 1 to 9 It is understood that an embodiment of the present application also provides a bread tunnel oven, comprising at least one of the above-mentioned baking units.

[0046] Compared with the prior art, the bread tunnel oven provided by the present invention adopts the above-mentioned baking unit. The first burner 10 and the second burner 20 can heat the air flowing in the first radiation tube 300 and the second radiation tube 400 respectively, so that the first radiation tube 300 and the second radiation tube 400 obtain different temperatures, so that the top of the bread obtains the required baking temperature to ensure the surface color and crispness, and the bottom of the bread obtains the required baking temperature to avoid the problem of undercookedness or overheating and hardness inside the bread, thereby improving the bread baking quality of the bread tunnel oven.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A baking unit, characterized in that: include: A first burner has a first combustion tube, the first combustion tube is connected to a first air distribution box and a first return air box, and the first return air box is connected to a first fan; A second burner has a second combustion tube, the second combustion tube is located on the side of the first burner and is connected to a second air distribution box and a second air return box, and the second air return box is connected to a second fan; A first tube row, comprising a plurality of first radiation tubes distributed below the first burner and the second burner, wherein two ends of the first radiation tubes are respectively connected to the first air distribution box and the first return air box; The second tube row is located directly below the first tube row and forms a baking channel suitable for the conveyor belt to pass through between the second tube row and the first tube row; The second tube row includes a plurality of second radiation tubes, and two ends of the second radiation tubes are respectively connected to the second air distribution box and the second air return box.

2. The baking unit according to claim 1, characterized in that: The first air distribution box includes a first straight air duct and a first air distribution air duct; wherein the first straight air duct is connected to the first combustion tube and extends along the axial direction of the first combustion tube; the first air distribution air duct is connected to the same end of each of the first radiation tubes and is connected to the extended end of the first straight air duct; The second air distribution box includes a second straight air duct and a second air distribution duct; wherein, the second straight air duct is connected to the second combustion tube and extends along the axial direction of the second combustion tube; the second air distribution duct is located directly below the first air distribution duct and is connected to the same end of each of the second radiation tubes, and the second air distribution duct is bent in the lateral direction of the conveyor mesh belt and connected to the extended end of the second straight air duct.

3. The baking unit according to claim 2, characterized in that: The air outlet of the first fan is connected to a first return air duct, which is in communication with the first combustion tube; the air outlet of the second fan is connected to a second return air duct, which is in communication with the second combustion tube; the first return air box includes a first return air duct corresponding to the first air distribution duct, and each of the first radiation tubes is in communication with the first return air duct; the second return air box includes a second return air duct corresponding to the second air distribution duct, and each of the second radiation tubes is in communication with the second return air duct.

4. The baking unit according to claim 1, characterized in that: A first air regulating assembly is provided on the side wall of the first return air box, and each of the first radiation tubes is connected to the first return air box through the first air regulating assembly, and the first air regulating assembly is used to individually and synchronously adjust the ventilation volume of each of the first radiation tubes; a second air regulating assembly is provided on the side wall of the second return air box, and each of the second radiation tubes is connected to the second return air box through the second air regulating assembly, and the second air regulating assembly is used to individually and synchronously adjust the ventilation volume of each of the second radiation tubes.

5. The baking unit according to claim 4, characterized in that: The first air regulating assembly and the second air regulating assembly have the same structure; wherein, the first air regulating assembly includes a plurality of independent air regulating units, and a synchronous regulating mechanism respectively connected to each of the independent air regulating units; each of the independent air regulating units is respectively connected to each of the first radiation tubes, and is respectively used to independently adjust the ventilation volume of each of the first radiation tubes; the synchronous regulating mechanism is used to drive each of the independent air regulating units to move synchronously.

6. The baking unit according to claim 5, characterized in that: The independent air conditioning unit comprises: A fixed sleeve, fixedly connected to the side wall of the first return air box and communicated with the first return air box, wherein a valve plate is arranged in the fixed sleeve, and the valve plate has a plurality of valve holes spaced apart along the circumference of the fixed sleeve; A rotating sleeve, one end of which is rotatably connected to the fixed sleeve, and the other end of which is rotatably matched with the first radiation tube, wherein a sealing plate is provided inside the rotating sleeve, and the sealing plate has a plurality of air holes spaced apart along the circumference of the rotating sleeve; Wherein, when the rotating sleeve rotates, the sealing plate can form a fully open state in which all the air holes are aligned with all the valve holes, a fully closed state in which all the air holes are staggered with all the valve holes, and a half-open state between the fully open state and the fully closed state.

7. The baking unit according to claim 6, characterized in that The synchronous adjustment mechanism comprises: A plurality of worm wheels are respectively sleeved on the outer circumference of each of the rotating sleeves and are rotatably matched with the rotating sleeves. A locking member is provided on the side wall of each of the worm wheels, and the locking member is used to lock the relative rotational freedom of the worm wheel and the rotating sleeve; The rotating shaft is rotatably connected to the side wall of the first return air box, and the rotating shaft has a plurality of worm gear sections connected in sequence, and each section of the worm gear is respectively meshed with each worm wheel.

8. The baking unit according to claim 7, characterized in that: A positioning plate is arranged on the outer periphery of the rotating sleeve, a circular arc hole is arranged on the positioning plate, and the locking member passes through the circular arc hole and is screwed to the worm gear; a shifting rod is arranged on the positioning plate.

9. The baking unit according to claim 6, characterized in that: A first annular groove is provided at one end of the rotating sleeve, and the end of the fixed sleeve is sealed and inserted in the first annular groove and rotatably cooperates with the first annular groove; a second annular groove is provided at the other end of the rotating sleeve, and one end of the first radiation tube is sealed and inserted in the second annular groove and rotatably cooperates with the second annular groove.

10. Bread tunnel oven, characterized in that, The invention comprises at least one baking unit according to any one of claims 1 to 9.

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