Hydrogen-doped natural gas special fuel premixing device with mixing and anti-backfire functions

Abstract

The utility model discloses a hydrogen-doped natural gas special fuel premixing device with mixing and anti-backfire functions, which comprises a premixing bin, a mixing bin main body is arranged in the premixing bin, a mixing cavity is arranged at the left end of the premixing bin, a connecting hole is formed in the premixing bin from top to bottom, and a detachable mixing bin main body inner core is arranged in the connecting hole. A circulation cavity is formed between the lower end of the mixing bin main body inner core and the connecting hole and is communicated with the mixing cavity. Through the arrangement of the mixing bin main body inner core, the flow speed of oxygen entering through the preheating oxygen inlet pipe in the mixing bin main body inner core is increased, meanwhile, hydrogen-doped natural gas in the circulation cavity is driven to be rapidly mixed, mixed gas is formed in the mixing cavity, and the mixing bin main body is separated from the circulation cavity; the passage of the preheated oxygen and the passage of the hydrogen-doped natural gas are separated, tempering is prevented from extending towards the defense line of the circulation cavity, and if tempering occurs, the tempering cannot enter the circulation cavity through the mixing cavity, so that the tempering phenomenon is avoided, and meanwhile the explosion risk is reduced.

Description

Technical Field

[0001] This utility model relates to the field of cutting torch fuel premixing technology, and in particular to a special fuel premixing device for hydrogen-blended natural gas with mixing and anti-backfire functions. Background Technology

[0002] Acetylene, propane, and hydrogen-blended natural gas are flammable and explosive gases. When mixed with oxygen or air, they will burn violently or even explode upon contact with an ignition source. Furthermore, under certain temperature and pressure conditions, they will decompose to produce carbon black and hydrogen gas, releasing a large amount of heat energy, which can lead to an explosion.

[0003] Backfire is one of the most common types of accidents that occur when using an oxy-fuel cutting torch. It occurs when the oxy-fuel flame enters the nozzle of the torch and burns backwards. Improper operation during cutting with these torches can easily lead to backfire, which can damage equipment or even cause an explosion, threatening the lives of operators.

[0004] Under high pressure, hydrogen has a high permeability, placing more stringent requirements on sealing materials. Hydrogen and natural gas have different densities; hydrogen, with its lower density, is prone to stratification, especially when flow rates are unstable or the premixing device is poorly designed. This makes it difficult to achieve a thorough and uniform mixture of the two gases, thus affecting combustion efficiency and stability. The incorporation of hydrogen alters the combustion characteristics of the fuel, such as combustion rate and flame temperature.

[0005] Compared to pure natural gas, hydrogen-blended natural gas burns more completely, improving combustion efficiency. This has driven the design optimization of the fuel blending chamber to better adapt it to this new type of blended fuel. Hydrogen has unique physicochemical properties; it is more prone to leakage than natural gas and poses an explosion risk under certain concentration ranges and conditions. Existing cutting torch fuel blending chambers suffer from structural complexity and the risk of backfire.

[0006] In view of this, the present invention is proposed to solve the above-mentioned technical problems. Utility Model Content

[0007] The purpose of this invention is to provide a special premixing device for hydrogen-blended natural gas with mixing and backfire prevention functions, so as to solve the technical problem that the main body of the cutting torch fuel mixing chamber has a backfire risk in the prior art.

[0008] The technical solution of this utility model is: a hydrogen-blended natural gas fuel premixing device with mixing and anti-backfire functions, comprising: a premixing chamber;

[0009] The premixing chamber contains a mixing chamber body. The left end of the premixing chamber has a mixing cavity. The premixing chamber has a connection hole from top to bottom. A detachable mixing chamber body core is installed in the connection hole. The lower end of the mixing chamber body core and the connection hole form a flow cavity, which is connected to the mixing cavity. The right end of the premixing chamber is equipped with a hydrogen-blended natural gas inlet pipe and a preheated oxygen inlet pipe. The hydrogen-blended natural gas inlet pipe is connected to the flow cavity, and the preheated oxygen inlet pipe is connected to the mixing chamber body.

[0010] Furthermore, the premixed chamber is equipped with a hydrogen-blended natural gas inlet, and the two ends of the hydrogen-blended natural gas inlet are connected to the hydrogen-blended natural gas inlet pipe and the flow chamber, respectively.

[0011] Furthermore, a preheated oxygen inlet is provided in the premixing chamber, and the two ends of the preheated oxygen inlet are connected to the preheated oxygen inlet pipe and the main body of the mixing chamber, respectively.

[0012] Furthermore, the left end of the premixing chamber also has a cutting oxygen outlet, and the premixing chamber is also equipped with a cutting oxygen inlet. The cutting oxygen outlet is connected to the cutting oxygen inlet, and the end of the cutting oxygen inlet opposite to the cutting oxygen outlet is connected to a cutting oxygen inlet pipe.

[0013] Furthermore, the connecting hole includes an upper hole and a lower hole that are connected from top to bottom;

[0014] The diameter of the upper hole is larger than the diameter of the lower hole;

[0015] The mixing chamber's main body includes an inner core body, which consists of an upper section and a lower section. The upper section is located inside the upper hole, and the lower section is located inside the lower hole. The diameter of the upper section is smaller than the diameter of the upper hole.

[0016] The upper outer circumferential wall has an annular protrusion. The lower edge of the annular protrusion abuts against the lower bottom wall of the upper hole. The annular protrusion and the lower bottom wall of the upper hole are connected by multiple pins.

[0017] Furthermore, the diameter of the lower section is smaller than the diameter of the lower hole, and a flow cavity is formed between the outer peripheral wall of the lower section and the inner wall of the lower hole;

[0018] The lower end has straight grooves on both sides, and the premix chamber has strip-shaped protrusions that match the straight grooves. The strip-shaped protrusions are detachably installed in the straight grooves, and the strip-shaped protrusions and the straight grooves are interference fit.

[0019] Furthermore, a vertical hole is provided at the bottom of the lower section from bottom to top, and the vertical hole is connected to a horizontal hole. The horizontal hole penetrates the outer wall of the lower section and is connected to the flow cavity.

[0020] Furthermore, a detachable hexagonal nut is provided on the annular protrusion. The outer wall of the hexagonal nut is provided with external threads. The hexagonal nut is threadedly connected to the upper hole, and a gap is left between the inner wall of the hexagonal nut and the upper section.

[0021] Furthermore, a circular hole is provided at the center of the upper section from top to bottom, and the inner wall of the circular hole is provided with internal threads.

[0022] By adopting the above technical solution, this utility model has the following beneficial effects:

[0023] The mixing chamber's inner core design accelerates the flow rate of oxygen entering through the preheated oxygen inlet pipe, simultaneously driving the hydrogen-blended natural gas in the flow chamber to mix rapidly and form a mixed gas. The mixing chamber is separated from the flow chamber, isolating the pathways for preheated oxygen and hydrogen-blended natural gas, preventing backfire from extending into the flow chamber. In the event of backfire, the backfire will not enter the flow chamber through the mixing chamber, preventing backfire into the gas cylinder and thus avoiding backfire, while also reducing the risk of explosion. Attached Figure Description

[0024] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but do not constitute an undue limitation of the present invention. Obviously, the drawings described below are merely some embodiments; those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the hydrogen-blended natural gas special fuel premixing device with mixing and backfire prevention functions provided in this embodiment of the application;

[0026] Figure 2 for Figure 1 Another structural schematic diagram of the hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions;

[0027] Figure 3 A cross-sectional view of a hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions provided in an embodiment of this application;

[0028] Figure 4 A schematic diagram of the inner core of the mixing chamber of a hydrogen-blended natural gas fuel premixing device with mixing and anti-backfire functions provided in this application embodiment.

[0029] Reference numerals in the attached diagram: 1. Premixing chamber; 2. Inner core of the mixing chamber; 3. Hydrogen-blended natural gas inlet pipe; 4. Preheated oxygen inlet pipe; 5. Cutting oxygen inlet pipe; 6. Hydrogen-blended natural gas inlet port; 7. Preheated oxygen inlet port; 8. Cutting oxygen inlet port; 9. Mixing chamber; 10. Cutting oxygen outlet; 11. Mixing chamber body; 12. Hexagonal socket nut; 21. Inner core body; 22. Internal thread; 23. Pin.

[0030] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the present invention in any way, but rather to illustrate the concept of the present invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0031] The specific embodiments of this utility model will be described in further detail with reference to the accompanying drawings.

[0032] See Figures 1 to 4 As shown in the embodiment of this application, a special fuel premixing device for hydrogen-blended natural gas with mixing and backfire prevention functions is provided, including: a premixing chamber 1, a mixing chamber body 11 inside the premixing chamber 1, a mixing chamber 9 at the left end of the premixing chamber 1, a connecting hole from top to bottom in the premixing chamber 1, a detachable mixing chamber body inner core 2 in the connecting hole, a flow cavity formed between the lower end of the mixing chamber body inner core 2 and the connecting hole, the flow cavity being connected to the mixing chamber 9, and a hydrogen-blended natural gas inlet pipe 3 and a preheated oxygen inlet pipe 4 in the right end of the premixing chamber 1, the hydrogen-blended natural gas inlet pipe 3 being connected to the flow cavity, and the preheated oxygen inlet pipe 4 being connected to the mixing chamber body 11.

[0033] In the above scheme, the mixing chamber core 2 is designed to accelerate the flow rate of oxygen entering through the preheated oxygen inlet pipe 4 within the mixing chamber core 2. This simultaneously drives the hydrogen-blended natural gas in the flow chamber to mix rapidly and form a mixed gas in the mixing chamber 9. The mixing chamber body 11 is separated from the flow chamber, thus separating the pathways for preheated oxygen and hydrogen-blended natural gas. This prevents backfire from extending into the flow chamber. If backfire occurs, it will not enter the flow chamber through the mixing chamber 9, preventing backfire to the gas cylinder and thus avoiding backfire. This also reduces the risk of explosion.

[0034] Among some possible solutions, see Figures 1 to 3 As shown, a hydrogen-blended natural gas inlet 6 is provided in the premixed chamber 1. The two ends of the hydrogen-blended natural gas inlet 6 are connected to the hydrogen-blended natural gas inlet pipe 3 and the flow chamber, respectively. The end of the hydrogen-blended natural gas inlet pipe 3 facing away from the premixed chamber 1 has an external thread. The end of the hydrogen-blended natural gas inlet pipe 3 facing away from the premixed chamber 1 is connected to the hydrogen-blended natural gas regulating valve through the external thread, which facilitates the quick disassembly and replacement of the hydrogen-blended natural gas regulating valve, saves costs and reduces processing difficulty. The end of the hydrogen-blended natural gas inlet pipe 3 near the premixed chamber 1 is welded to the premixed chamber 1.

[0035] Among some possible solutions, see Figures 1 to 3 As shown, a preheated oxygen inlet 7 is provided in the premixing chamber 1. The two ends of the preheated oxygen inlet 7 are connected to the preheated oxygen inlet pipe 4 and the main body 11 of the mixing chamber, respectively. The preheated oxygen inlet pipe 4 and the hydrogen-blended natural gas inlet pipe 3 have the same structure and installation method. The preheated oxygen inlet pipe 4 is connected to the preheated oxygen regulating valve.

[0036] Among some possible solutions, see Figures 1 to 3 As shown, the left end of the premixed chamber 1 also has a cut oxygen outlet 10, and the premixed chamber 1 is also provided with a cut oxygen inlet 8. The cut oxygen outlet 10 is connected to the cut oxygen inlet 8. The end of the cut oxygen inlet 8 away from the cut oxygen outlet 10 is connected to a cut oxygen inlet pipe 5. The cut oxygen inlet pipe 5 has the same structure and installation method as the hydrogen-blended natural gas inlet pipe 3. The cut oxygen inlet pipe 5 is connected to the cut oxygen regulating valve.

[0037] Among some possible solutions, see Figure 3 and Figure 4 As shown, the connecting hole includes an upper hole and a lower hole that are connected from top to bottom. The diameter of the upper hole is larger than that of the lower hole. The inner core 2 of the mixing chamber body includes an inner core body 21, which includes an upper section and a lower section. The upper section is located in the upper hole, and the lower section is located in the lower hole. The diameter of the upper section is smaller than that of the upper hole. The outer circumferential wall of the upper section has an annular protrusion. The lower edge of the annular protrusion abuts against the lower bottom wall of the upper hole. The annular protrusion and the lower bottom wall of the upper hole are connected by multiple pins 23. The diameter of the pins 23 decreases from top to bottom.

[0038] In the above scheme, when installing the inner core body 21, the inner core body 21 is inserted into the connecting hole, so that the lower edge of the annular protrusion abuts against the lower bottom wall of the upper hole, and the lower bottom wall of the upper hole has multiple mating holes that cooperate with the pins 23. When the lower edge of the annular protrusion abuts against the lower bottom wall of the upper hole, the multiple pins 23 are respectively inserted into the multiple mating holes, and the premixing chamber 1 and the mixing chamber body inner core 2 are fixed by the pins 23, so that the annular protrusion and the premixing chamber 1 are mated by surface, which plays the role of sealing and precise positioning.

[0039] Among some possible solutions, see Figure 3 and Figure 4 As shown, the diameter of the lower section is smaller than the diameter of the lower hole. A flow cavity is formed between the outer peripheral wall of the lower section and the inner wall of the lower hole. There are straight grooves on both sides of the bottom of the lower end. The premixing chamber 1 has a strip-shaped protrusion that matches the straight groove. The strip-shaped protrusion is detachably set in the straight groove. The strip-shaped protrusion and the straight groove are interference fit (mortise and tenon structure).

[0040] In the above scheme, the premixing chamber 1 is fixedly connected to the inner core 2 of the mixing chamber body by the matching of the straight groove with the strip protrusion of the premixing chamber 1, which plays a role in good sealing and precise positioning.

[0041] Among some possible solutions, see Figure 3 and Figure 4 As shown, a vertical hole is provided at the bottom of the lower section from bottom to top. The vertical hole is connected to a horizontal hole. The horizontal hole penetrates the outer wall of the lower section and is connected to the flow cavity.

[0042] In the above scheme, the diameters of the horizontal hole, the vertical hole, and the preheated oxygen inlet 7 are increased sequentially, which makes the diameter of the preheated oxygen passage gradually decrease. By changing the diameter of the preheated oxygen passage, the flow rate of preheated oxygen is accelerated, which facilitates the rapid mixing of hydrogen-blended natural gas.

[0043] Among some possible solutions, see Figure 3 As shown, a detachable internal hexagonal nut 12 is provided on the annular protrusion. The outer wall of the internal hexagonal nut 12 is provided with external threads. The internal hexagonal nut 12 is threadedly connected to the upper hole. A gap is left between the inner wall of the internal hexagonal nut 12 and the upper section.

[0044] In the above scheme, when fixing the inner core body 21, the internal hexagonal nut 12 is rotated to make the internal hexagonal nut 12 screw downward, thereby pressing the inner core body 21 down, and then the pin 23 of the inner core body 21 is inserted into the mating hole of the premix chamber 1. At the same time, the strip-shaped protrusion of the premix chamber 1 is embedded in the straight groove of the lower section, thus completing the fixing of the inner core body 21 and the sealing of the flow cavity.

[0045] Among some possible solutions, see Figure 4 As shown, a circular hole is provided in the center of the upper section from top to bottom. The inner wall of the circular hole is provided with an internal thread 22. Since the strip-shaped protrusion and the straight groove are interference fit, and the diameter of the pin 23 decreases from top to bottom, in order to facilitate the removal of the inner core body 21, the external screw can be screwed into the circular hole through the internal thread 22. After removing the internal hex nut 12, the inner core body 21 and the pin 23 can be pulled out together by pulling the external screw upward.

[0046] This specific embodiment is merely an explanation of the utility model and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of protection of this utility model.

Claims

1. A hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions, characterized in that, include: Premixed warehouse (1); The premixed chamber (1) has a mixing chamber body (11) inside. The left end of the premixed chamber (1) has a mixing cavity (9). The premixed chamber (1) has a connecting hole from top to bottom. A detachable mixing chamber body core (2) is provided in the connecting hole. A flow cavity is formed between the lower end of the mixing chamber body core (2) and the connecting hole. The flow cavity is connected to the mixing cavity (9). The right end of the premixed chamber (1) is provided with a hydrogen-doped natural gas inlet pipe (3) and a preheated oxygen inlet pipe (4). The hydrogen-doped natural gas inlet pipe (3) is connected to the flow cavity. The preheated oxygen inlet pipe (4) is connected to the mixing chamber body (11).

2. The hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions according to claim 1, characterized in that, The premixed chamber (1) is provided with a hydrogen-doped natural gas inlet (6), and the two ends of the hydrogen-doped natural gas inlet (6) are respectively connected to the hydrogen-doped natural gas inlet pipe (3) and the flow chamber.

3. The hydrogen-blended natural gas premixing device with mixing and backfire prevention functions according to claim 2, characterized in that, The premixing chamber (1) is provided with a preheated oxygen inlet (7), and the two ends of the preheated oxygen inlet (7) are respectively connected to the preheated oxygen inlet pipe (4) and the mixing chamber body (11).

4. The hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions according to claim 3, characterized in that, The premix chamber (1) also has a cutting oxygen outlet (10) at the left end, and a cutting oxygen inlet (8) is also provided in the premix chamber (1). The cutting oxygen outlet (10) is connected to the cutting oxygen inlet (8), and a cutting oxygen inlet pipe (5) is connected to the end of the cutting oxygen inlet (8) away from the cutting oxygen outlet (10).

5. The hydrogen-blended natural gas premixing device with mixing and backfire prevention functions according to claim 1, characterized in that, The connecting hole includes an upper hole and a lower hole that are connected from top to bottom; The diameter of the upper hole is larger than the diameter of the lower hole; The mixing chamber core (2) includes a core body (21), which includes an upper section and a lower section. The upper section is located inside the upper hole, and the lower section is located inside the lower hole. The diameter of the upper section is smaller than the diameter of the upper hole. The upper outer circumferential wall has an annular protrusion, the lower edge of which abuts against the lower bottom wall of the upper hole, and the annular protrusion and the lower bottom wall of the upper hole are connected by multiple pins (23).

6. The hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions according to claim 5, characterized in that, The diameter of the lower section is smaller than the diameter of the lower hole, and the flow cavity is formed between the outer peripheral wall of the lower section and the inner wall of the lower hole; The lower end has straight grooves on both sides, and the premix chamber (1) has strip-shaped protrusions that cooperate with the straight grooves. The strip-shaped protrusions are detachably disposed in the straight grooves, and the strip-shaped protrusions are interference-fitted with the straight grooves.

7. The hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions according to claim 6, characterized in that, The lower section has a vertical hole at its bottom from bottom to top, which is connected to a horizontal hole. The horizontal hole penetrates the outer wall of the lower section and is connected to the flow cavity.

8. The hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions according to claim 5, characterized in that, The annular protrusion is provided with a detachable internal hexagonal nut (12). The outer wall of the internal hexagonal nut (12) is provided with external threads. The internal hexagonal nut (12) is threadedly connected to the upper hole. There is a gap between the inner wall of the internal hexagonal nut (12) and the upper section.

9. The hydrogen-blended natural gas fuel premixing device with mixing and backfire prevention functions according to claim 5, characterized in that, The upper section has a circular hole from top to bottom at its center, and the inner wall of the circular hole is provided with an internal thread (22).

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