Tuyere spraying device and design method of tuyere spraying system to prevent flashback

Abstract

The present invention relates to a tuyere blowing device and a method for designing a tuyere blowing system to prevent backfire, and belongs to the technical field of blast furnace blowing. The tuyere blowing device includes a gun body and a gun head, and the gun body and the gun head are connected as a whole by welding. The method includes obtaining the composition of the blowing gas, calculating the critical backfire speed of the blowing gas, obtaining the blowing amount of the blowing gas, selecting the number of tuyere blowing, and calculating the blowing speed of the blowing gas. The present invention changes the structure of the tuyere blowing device so that the blowing gas can increase the blowing speed; through the correct matching of the blowing gas with the blowing amount and the blowing speed, the blowing gas can be evenly and stably blown, and the backfire of the blowing gas and the burning of the blowing device can be prevented, thereby extending the life of the blowing device, making the blast furnace stable and smooth, achieving carbon reduction and consumption reduction of the blast furnace, and achieving the expected goal of the gas injection.

Description

Technical Field

[0001] The invention belongs to the technical field of blast furnace injection, and relates to a tuyere injection device and a design method for a tuyere injection system to prevent backfire. Background Art

[0002] Hydrogen metallurgy is an important direction for current low-carbon development and energy transformation, and it is also the fundamental way out for the greening of the steel industry. As the most active reducing agent, hydrogen has higher reduction efficiency and reduction rate than carbon. Injecting hydrogen-rich gas instead of carbon for reduction during blast furnace ironmaking can greatly reduce smoke pollutants and carbon dioxide emissions, and improve ironmaking production efficiency. The existing hydrogen-rich gas tuyere injection device has a single structure, and the gas composition cannot be correctly matched with the injection volume and injection speed. It is easy to cause flashback accidents, which will cause the injection device to burn, affect the life of the injection device, and have a certain negative impact on the normal production of the blast furnace. Therefore, how to safely and stably inject hydrogen-rich gas, thereby extending the life of the injection device and making the blast furnace stable and smooth, has become a problem that needs to be solved urgently. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a tuyere blowing device and a design method for preventing backfire of a tuyere blowing system, so as to solve the technical problem that the blown gas is prone to backfire, thereby burning the tuyere blowing device, affecting the life of the tuyere blowing device, and preventing stable blowing.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A tuyere blowing device comprises a gun body and a gun head, wherein the gun body and the gun head are connected as a whole by welding.

[0006] Optionally, the gun tip is tapered.

[0007] Optionally, the angle between the tapered portion of the gun tip and its axis is 0°≤θ≤30°.

[0008] Optionally, the tuyere blowing device is made of heat-resistant stainless steel.

[0009] A method for designing a flashback prevention tuyere blowing system, applied to the above-mentioned tuyere blowing device, comprises the following steps:

[0010] S1: Obtain the composition of the blowing gas;

[0011] S2: Calculate the critical tempering speed V0 of the injected gas;

[0012] S3: obtaining design parameters of the injection gas;

[0013] S4: Calculate the injection speed V of the injection gas and determine whether the critical tempering speed V0 is reached.

[0014] Optionally, the critical tempering speed V0 formula in S2 is:

[0015] V0=∑V i X i / C i ) / ∑X i / C i )

[0016] Where: V0, V i , X i and C i They are respectively the critical tempering velocity of the mixed gas, the critical tempering velocity of a single fuel gas, the volume fraction of a single fuel gas in the absence of inert gas, and the volume fraction of the fuel gas at the maximum propagation velocity.

[0017] Optionally, obtaining the design parameters of the blowing gas in S3 includes obtaining the blowing gas blowing volume Q, obtaining the blowing gas temperature T, obtaining the blowing gas blowing pressure P, obtaining the tube diameter D of the tuyere blowing device, and obtaining the tuyere blowing number n.

[0018] Optionally, when the mixed gas contains inert gas and the mixed gas temperature is t, the critical tempering speed of the mixed gas should be corrected to:

[0019] V0′=βV0

[0020] Where: α is the inert gas correction factor, β is the temperature correction factor.

[0021] Optionally, the injection velocity V formula is:

[0022]

[0023] The beneficial effects of the present invention are:

[0024] The present invention changes the structure of the tuyere blowing device so that the blowing speed of the blowing gas can be increased; by correctly matching the blowing gas with the blowing amount and the blowing speed, uniform and stable blowing of the blowing gas can be achieved, and flashback of the blowing gas and burning of the blowing device can be prevented, thereby extending the life of the blowing device, allowing the blast furnace to run stably and smoothly, achieving carbon reduction and consumption reduction, and achieving the expected goal of blowing gas.

[0025] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0027] Figure 1 It is a structural schematic diagram of an embodiment of the present invention.

[0028] Figure numerals: 1-gun body; 2-gun head; 3-welding position. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0031] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] See also Figure 1 The present invention provides a tuyere blowing device, comprising a gun body 1 and a gun head 2, the gun body 1 and the gun head 2 are connected as a whole by welding, and a welding position 3 is located between the gun body 1 and the gun head 2. The angle of the front end of the tuyere blowing device is 0°≤θ≤30°. The tuyere blowing device is made of heat-resistant stainless steel.

[0033] To achieve the above-mentioned purpose and other related purposes, the present application also provides a method for designing a flashback prevention tuyere injection system, comprising the following steps:

[0034] S1: Obtain the composition of the blowing gas;

[0035] S2: Calculate the critical tempering speed V0 of the injected gas;

[0036] S3: obtaining design parameters of the injection gas;

[0037] S4: Calculate the injection speed V of the injection gas and determine whether the critical tempering speed V0 is reached.

[0038] Optionally, the formula for the critical tempering speed V0 in S2 is:

[0039] V0=∑V i X i / C i ) / ∑X i / C i )

[0040] Where: V0, V i , X i and C i They are the critical tempering velocity of the mixed gas (m / s), the critical tempering velocity of a single fuel gas (m / s), the volume fraction of a single fuel gas in the absence of inert gas (%), and the volume fraction of the fuel gas at its maximum propagation velocity (%).

[0041] Optionally, obtaining the design parameters of the blowing gas in S3 includes obtaining the blowing gas blowing volume Q, obtaining the blowing gas temperature T, obtaining the blowing gas blowing pressure P, obtaining the tube diameter D of the tuyere blowing device, and obtaining the tuyere blowing number n.

[0042] Optionally, when the mixed gas contains inert gas and the mixed gas temperature is t, the critical tempering speed of the mixed gas should be corrected to:

[0043] V′0=αβV0

[0044] Where: α is the inert gas correction factor, β is the temperature correction factor.

[0045] Optionally, the injection velocity V formula is:

[0046]

[0047] To further illustrate the design method, a specific embodiment is used below to further illustrate the design method, but the design method is not limited to the following embodiment.

[0048] S1: Obtain the composition table of the injected gas, CO content 20%, CO2 content 10%, H2 content 45%, N2 content 25%;

[0049] S2: Calculate the critical tempering speed of the injected gas V0 = 75.13 m / s;

[0050] S3: Get the injection gas injection volume Q = 12000m 3 / h, obtain the blowing gas temperature T = 30 ° C, obtain the blowing gas blowing pressure P = 480 KPa, obtain the tuyere blowing device pipe diameter D = 26 mm, and obtain the tuyere blowing number n = 15;

[0051] S4: Calculate the injection velocity V of the injection gas = 80.97 m / s, which is greater than the critical tempering velocity V0 of 75.13 m / s, thereby ensuring that the injection gas will not temper.

[0052] The tuyere blowing device and the design method of the tuyere blowing system for preventing flashback of the present invention can realize uniform and stable blowing of the blowing gas, prevent flashback of the blowing gas and burning of the blowing device, thereby extending the life of the blowing device, allowing the blast furnace to run stably and smoothly, achieving carbon reduction and consumption reduction, and achieving the expected goal of blowing gas.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for designing a flashback prevention tuyere injection system, characterized in that: A tuyere blowing device is used, the tuyere blowing device comprises a gun body and a gun head, the gun body and the gun head are connected as a whole by welding; the gun head has a taper, and the angle between the taper portion of the gun head and its axis is 0°≤θ≤30°, and the tuyere blowing device is made of heat-resistant stainless steel; The design method comprises the following steps: S1: Obtain the composition of the blowing gas; S2: Calculate the critical tempering speed V0 of the injected gas; S3: obtaining design parameters of the injection gas; S4: Calculate the injection speed V of the injection gas and determine whether the critical tempering speed V0 is reached; Among them, the formula for the critical tempering speed V0 in S2 is: V0=(∑V i X i / C i ) / (∑X i / C i ) Where: V0, V i , X i and C i They are the critical tempering speed of mixed gas, the critical tempering speed of single fuel gas, the volume fraction of a single fuel gas without inert gas, and the volume fraction of the fuel gas at the maximum propagation speed. The design parameters for the injection gas obtained in S3 include the injection gas injection volume Q, in units of m 3 / h; obtain the temperature T of the injected gas, in °C; obtain the injection pressure P of the injected gas, in kPa; obtain the diameter D of the tuyere injection device, in mm, and obtain the number of tuyere injections n; The formula for the injection velocity V is:

2. The method for designing a flashback prevention tuyere injection system according to claim 1, characterized in that: When the mixed gas contains inert gas and the mixed gas temperature is t, the critical tempering speed of the mixed gas should be corrected to: V′0=αβV0 Where: α is the inert gas correction factor, β is the temperature correction factor.

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