Steam deceleration diffuser and steam box comprising same

Abstract

The invention discloses a steam speed-reducing diffuser and a steam box comprising the steam speed-reducing diffuser, the steam speed-reducing diffuser comprises a T-shaped pipe, the lower part of the T-shaped pipe is provided with a steam inlet, the two ends of the T-shaped pipe are respectively connected with a square elbow, and the outlets of the square elbows are respectively connected with steam inlets located at the top point of the bottom end of a W-shaped buffer pipe plate; the top end of the W-shaped buffer tube plate is connected with a right-angle adapter plate tube, the tail end of the right-angle adapter plate tube is connected with a mounting plate, and a through hole matched with a tube opening of the right-angle adapter plate tube is formed in the mounting plate; a turbulent flow column is transversely arranged in the W-shaped buffer tube plate and is perpendicular to the side wall of the W-shaped buffer tube plate; the steam speed-reducing diffusion device adopts a multi-stage speed-reducing structure, so that the flow rate of steam entering the steam box is greatly reduced, the uniformity of the outlet speed is maintained, piston type gas replacement is realized, the gas replacement efficiency of the steam box is greatly improved, the water consumption is reduced, the oxygen discharging time is greatly shortened, the gas replacement efficiency is high, and the water-saving performance is good.

Description

Technical Field

[0001] This invention belongs to the field of steam oven technology, specifically relating to a steam deceleration diffuser and a steam oven including the steam deceleration diffuser. Background Technology

[0002] With the development of the times, people's living standards have improved significantly, and their demand for green and healthy food has been increasing. Steam cooking is becoming increasingly popular due to its green and healthy advantages.

[0003] In traditional steam ovens, when steam is introduced, it mixes with the air inside the cavity. During steam cooking, the high temperature causes the air to oxidize the nutrients in the food, reducing its nutritional content. Most traditional steam ovens are open systems, and the mixed gas discharged from the vents contains a large amount of water vapor, leading to water and energy waste. Currently, mainstream steam ovens are adopting a "top-down" gas replacement method. This is achieved by adding steam pipes and steam holes inside the oven cavity, increasing the outlet area, and arranging multiple steam inlets at the top of the oven to evenly spray steam downwards for gas replacement. However, this method places the heating element at the top of the cavity, occupying additional space and reducing the effective volume of the steam oven. It also results in uneven steam flow distribution, affecting the gas replacement effect and causing severe steam-air mixing. Furthermore, because it uses a downward steam injection method, the severe mixing of steam and air results in a large amount of steam in the mixed gas discharged from the cavity, causing waste of water and heat. The more severe the mixing of steam and air, the worse the gas replacement effect; vertical injection of steam should be avoided. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a steam deceleration diffuser and a steam chamber containing the steam deceleration diffuser. By changing the position of the steam chamber's air inlet and adding a steam deceleration diffusion device, the speed at which steam enters the steam chamber is reduced, the wall adsorption effect of steam is reduced, and the traditional mixed gas replacement is transformed into piston gas replacement, significantly reducing the oxygen removal time, resulting in high gas replacement efficiency and good water-saving performance.

[0005] To achieve the above objectives, the present invention employs the following technical solution: A steam deceleration diffuser includes a T-shaped tube with a steam inlet at its lower part. Right-angle elbows are connected to both ends of the T-shaped tube, and the outlets of the right-angle elbows are connected to the steam inlets at the bottom apex of a W-shaped buffer tube plate. A right-angle adapter plate is connected to the top of the W-shaped buffer tube plate, and a mounting plate is connected to the tail end of the right-angle adapter plate. The mounting plate has through holes that match the openings of the right-angle adapter plate. The W-shaped buffer tube sheet has turbulence columns installed horizontally perpendicular to its sidewall.

[0006] The present invention also has the following technical features: Preferably, multiple turbulence columns are provided and distributed in a triangular array.

[0007] Furthermore, the sides of the triangular array of the turbulence-disrupting columns are parallel to the sides of the W-shaped buffer tube plate, the angle β between the sides of the triangular array and the vertical direction is 30°~60°, and the vertical distance between each turbulence-disrupting column is 6~8 mm.

[0008] Furthermore, the diameter D of the aforementioned turbulence column is 3 to 4.5 millimeters.

[0009] Preferably, the length of the pipe opening of the right-angle adapter plate is 0.55 to 0.8 times the length of the steam oven.

[0010] Preferably, the length of the horizontal pipe on one side of the T-shaped pipe is 0.2 to 0.35 times the length of the steamer, and the diameter is 8 to 12 mm.

[0011] The present invention also protects a steam oven, including the steam deceleration diffuser as described above.

[0012] Preferably, the steam deceleration diffuser is connected to the top of one side of the steam generator, and the steam box is provided with an exhaust port near the bottom.

[0013] Furthermore, the distance between the exhaust vent and the bottom of the steamer is 5 to 15 millimeters.

[0014] Compared with the prior art, the present invention has the following technical effects: This invention utilizes a steam deceleration diffuser to reduce steam velocity and the proportion of convective mass transfer, effectively minimizing air-steam mixing and achieving "piston-like" gas replacement within the steam chamber. This significantly reduces the minimum oxygen content at the furnace core, decreases steam wall adsorption effects, and drastically reduces oxygen removal time. By reducing the steam inlet velocity and increasing the inlet area, the invention avoids the need for additional steam pipes and flow dividers within the chamber. This not only effectively improves gas replacement performance and reduces steam waste, resulting in good water conservation, but also avoids reducing internal space and impacting heating wire arrangement, thus minimizing internal space waste and improving overall thermal efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the steam deceleration diffuser of the present invention; Figure 2 This is a front view of the steam deceleration diffuser of the present invention; Figure 3 This is a side view of the steam deceleration diffuser of the present invention; Figure 4 This is a schematic diagram of the internal structure of the steam deceleration diffuser of the present invention; Figure 5 This is a schematic diagram of the steamer structure of the present invention; Figure 6 The diagram shows the oxygen content test results of the steam oven of this invention and various conventional steam oven models. The meanings of the labels in the above figures are as follows: 1-Steam inlet, 2-T-pipe, 3-Right-angle elbow, 4-W-shaped buffer tube sheet, 5-Right-angle transition plate tube, 6-Mounting plate, 7-Through hole, 8-Break column, 9-Exhaust hole. Detailed Implementation

[0016] The following detailed explanation of the specific content of the present invention is provided in conjunction with embodiments. These descriptions are intended to explain the present invention and not to limit it.

[0017] Example 1 refer to Figures 1 to 4 As shown, this embodiment provides a steam deceleration diffuser, including a T-shaped tube 2. A steam inlet 1 is located at the lower part of the T-shaped tube 2. Right-angle elbows 3 are connected to both ends of the T-shaped tube 2. The outlets of the right-angle elbows 3 are connected to the steam inlets at the bottom apex of a W-shaped buffer tube plate 4. A right-angle transition plate 5 is connected to the top of the W-shaped buffer tube plate 4, and a mounting plate 6 is connected to the tail end of the right-angle transition plate 5. The mounting plate 6 has through holes 7 that match the openings of the right-angle transition plate 5. Steam generated by the steam generator enters the T-shaped tube 2 from the steam inlet 1. The steam flow direction changes from vertical to horizontal after passing through the T-shaped tube 2. The flow velocity is reduced by a 90° turn, and then further reduced by a 90° turn after passing through the right-angle elbows 3. The steam then enters the W-shaped buffer tube plate 4 through the steam inlets at the bottom apex of the right-angle elbows 3 and the W-shaped buffer tube plate 4. Turbulence columns 8 are horizontally installed perpendicular to the sidewalls of the W-shaped buffer tube plate 4. The turbulence column 8 further turbulents the steam entering the W-shaped buffer tube plate 4, further slowing its flow velocity. The steam passing through the W-shaped buffer tube plate 4 then enters the right-angle transition tube 5 through its top outlet, where it again undergoes a 90° turn to slow its flow velocity, finally exiting from the outlet of the right-angle transition tube 5 and entering the working chamber of the steam chamber. A mounting plate 6 is provided on the outside of the right-angle transition tube 5, which is used to fix the steam deceleration diffuser to one side of the steam chamber.

[0018] To control the efficiency of steam slowdown, multiple turbulence columns 8 are arranged in a triangular array. The sides of the triangular array of turbulence columns 8 are parallel to the sides of the W-shaped buffer tube plate 4, and the angle β between the sides of the triangular array and the vertical direction is 30°~60°. The vertical distance d between each turbulence column 8 is... rThe diameter of the spoiler column 8 is 6-8 mm. The diameter D of the spoiler column 8 is 3-4.5 mm. There are 2-5 layers in total, numbered 1, 2, 3, ... from bottom to top. The distance between adjacent spoiler columns 8 is 8-12 mm.

[0019] The steamer has a length of L, a width of B, and a height of H. The device length is L. O The dimensions are 0.75 0.85 B, and the device height H. D The diameter is 0.2H to 0.35H, and the width of the device B is 0.03 L to 0.05 L.

[0020] The length of the pipe opening of the right-angle adapter plate 5 is 0.55~0.8 times the length of the steam oven.

[0021] The length Ls of the horizontal pipe on one side of T-shaped pipe 2 is 0.2~0.35 of the length of the steam oven, and the diameter is 8~12 mm.

[0022] The angle α between the four sides of the W-shaped buffer tube sheet and the horizontal direction is 30°~60°, and the height H is... J 0.4 H D ~ 0.5 H D ; Compared to traditional mixed-type gas replacement, piston-type gas replacement has the advantages of better gas replacement performance and lower minimum oxygen content. Based on the following formulas for calculating the replacement time to achieve the same oxygen content using both mixed-type and piston-type methods, it can be seen that piston-type gas replacement is significantly superior to mixed-type.

[0023] (1) (2) The mass transfer process of water vapor satisfies the flow-diffusion equation: (3) (4) in, The mass flux of water vapor. The mass concentration of water vapor. The velocity of water vapor. is the molecular diffusion coefficient of water vapor in air.

[0024] Mass transfer of water vapor consists of convection and diffusion terms. The convection term characterizes the directional movement of water vapor particles and exhibits strong directionality. It is closely related to the arrangement of the water vapor inlet holes and the inlet velocity, and its expression is: (5) The diffusion term is caused by the concentration gradient of water vapor, which moves from regions of high concentration to regions of low concentration. The diffusion term is: (6) Pecklet number The value is represented by a dimensionless parameter, indicating the ratio of convective mass transfer rate to diffusion mass transfer rate. If... A high velocity indicates a very slow diffusion rate, where the effect of diffusion on concentration is negligible. Conversely, when... When the diffusion rate is 1, it indicates that the diffusion is very rapid, and diffusion dominates the change in concentration. The formula is: (7) The steam chamber volume is VL and the initial steam mass flow rate remains constant. When the steam velocity is high, Pe is also high, and the proportion of water vapor convective mass transfer to the total water vapor mass transfer is relatively large, with water vapor mainly transferred along the flow direction.

[0025] Considering the limited volume of the steam oven, steam will flow along the walls, causing severe wall adhesion and slowing down the rate at which the oxygen content at the furnace core decreases, resulting in poor oxygen removal performance. Furthermore, the replacement method and steam properties of the piston-type gas replacement system require steam to enter horizontally from above at a slower velocity to reduce wall adhesion caused by excessively high flow rates. In this case, the diffusion and mass transfer of steam dominates, thus achieving piston-type gas replacement and expelling the denser, lower-temperature air from the lower exhaust vents, meeting the requirements for efficient oxygen removal.

[0026] By applying Fick's law to solve the unsteady field of steam diffusion within the steam chamber, the required steam velocity for piston-like gas displacement can be calculated. Since the steam enters horizontally, assuming its vertical velocity component is constant at zero, the mass diffusion flow rate per unit distance at the water vapor-air interface is: (8) Where t is time, L is the length of the steam chamber, D is the diffusion coefficient, and J is the diffusion flux.

[0027] The diffusion flux at the water vapor-air interface is: (9) For the steam flow to achieve piston-like displacement, the following must be satisfied: (10) The range of water vapor flow rates is: (11) (12) The outlet area S of the device is: (13) Assuming a constant steam flow rate, the range of values ​​for the outlet area S of the steam deceleration and diffusion device can be obtained as follows: (14) Where Hout is the outlet height of the device, S is the outlet area of ​​the device, and qv is the volumetric flow rate of water vapor in the steam chamber.

[0028] The steam deceleration and diffusion device of this invention employs a multi-stage deceleration structure, which greatly reduces the steam flow rate entering the steam chamber and maintains the uniformity of the outlet velocity, achieving piston-type gas replacement and significantly improving gas replacement efficiency while reducing water consumption. Under the same steam flow rate, the deceleration and diffusion device proposed in this invention can improve the gas replacement effect by 65%, significantly enhancing gas replacement performance, reducing steam loss due to wall adsorption, resulting in a rapid decrease in oxygen content at the furnace core, low oxygen content in a stable state, and reduced susceptibility to wall adsorption and swirling phenomena.

[0029] Example 2 like Figure 5 As shown in the figure, this embodiment provides a steam oven, including a steam deceleration diffuser, which is connected to the top of the steam generator side of the steam oven. The steam oven is provided with an exhaust port 9 near the bottom, and the distance between the exhaust port 9 and the bottom of the steam oven is 5 to 15 mm.

[0030] The steam oven of this invention incorporates a steam deceleration and diffusion device. This device employs a multi-stage deceleration structure, significantly reducing the steam velocity entering the steam oven and maintaining uniformity of the outlet velocity. This achieves piston-like gas replacement, greatly improving gas replacement efficiency and reducing water consumption. Under the same steam flow rate, the deceleration and diffusion device proposed in this invention can improve the gas replacement effect by 65%, significantly enhancing gas replacement performance, reducing steam loss due to wall adsorption in the steam oven, resulting in a rapid reduction in oxygen content at the furnace core, low oxygen content in a stable state, and less susceptibility to wall adsorption and swirling phenomena. This invention significantly reduces the steam velocity through a multi-stage deceleration structure, enabling the steam to form a "piston layer" for piston-like gas replacement, resulting in strong gas replacement performance. Furthermore, the "steam piston" pushes the low-temperature air at the bottom to be discharged from the exhaust port 9, reducing steam and heat loss during the gas replacement process. This improves the gas replacement speed while minimizing steam and heat loss, and does not occupy the effective volume of the steam oven.

[0031] Figure 6 This is a test chart showing the oxygen content at the core of the steam oven of this invention compared to various conventional steam oven models; from... Figure 6 It can be seen that, At a constant steam flow rate, the steam box of this invention exhibits superior oxygen removal performance. The rate of oxygen reduction at the furnace core is significantly faster than other types of steam boxes, and the lowest oxygen content at the furnace core is less than 0.1%, significantly lower than other types of steam boxes. Therefore, the steam provided by this invention is significantly superior to similar products in both oxygen removal speed and minimum oxygen content, giving it high market competitiveness. In the description of this invention, it should be noted that the terms "top", "bottom", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] The above embodiments are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A steam de-acceleration diffuser characterized by, It includes T-shaped pipe (2), the lower part of T-shaped pipe (2) is provided with steam inlet (1), both ends of T-shaped pipe (2) are connected with elbow (3) respectively, the outlet of elbow (3) is connected with the steam inlet of W-shaped buffer pipe plate (4) at the top of bottom end respectively, the top of W-shaped buffer pipe plate (4) is connected with right-angle adapter plate pipe (5), the tail end of right-angle adapter plate pipe (5) is connected with mounting plate (6), the mounting plate (6) is provided with through hole (7) matched with the pipe opening of right-angle adapter plate pipe (5). The W-shaped buffer pipe plate (4) is vertically installed with spoiler column (8) in the lateral wall.

2. The steam de-accelerating diffuser of claim 1, wherein, The spoiler column (8) is provided with multiple, and is distributed in triangular array.

3. The steam de-accelerating diffuser of claim 2, wherein, The side of triangular array of spoiler column (8) is arranged in parallel with the side of W-shaped buffer pipe plate (4), the included angle β between triangular array side and vertical direction is 30°-60°, and the distance of each spoiler column (8) in vertical direction is 6-8 mm.

4. The steam de-accelerating diffuser of claim 2, wherein, The diameter D of spoiler column (8) is 3-4.5 mm.

5. The steam de-accelerating diffuser of claim 1, wherein, The length of pipe opening of right-angle adapter plate pipe (5) is 0.55-0.8 of the length of steam box.

6. The steam de-accelerating diffuser of claim 1, wherein, The length of horizontal pipeline of one side of T-shaped pipe (2) is 0.2-0.35 of the length of steam box, and the diameter is 8-12 mm.

7. A steaming box, characterized by It includes the steam deceleration diffuser of any one of claims 1 to 6.

8. The steamer as claimed in claim 7, wherein, The steam deceleration diffuser is connected with the top of one side of steam box steam generator, and the steam box is provided with exhaust hole (9) close to the bottom.

9. The steamer as claimed in claim 8, wherein, The distance between exhaust hole (9) and the bottom of steam box is 5-15 mm.

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