CN220249989U

CN220249989U - Heat treatment furnace

Info

Publication number: CN220249989U
Application number: CN202320073413.7U
Authority: CN
Inventors: 马家骥; 于浩淼; 李立; 汤小超; 刘磊; 谢宇; 任中一; 王磊
Original assignee: Qian'an Iron And Steel Co Of Shougang Corp; Beijing Shougang Co Ltd
Current assignee: Qian'an Iron And Steel Co Of Shougang Corp; Beijing Shougang Co Ltd
Priority date: 2023-01-10
Filing date: 2023-01-10
Publication date: 2023-12-26
Anticipated expiration: 2033-01-10

Abstract

The application discloses a heat treatment furnace. The radiant tube of this heat treatment furnace includes U type pipe and back flow, and wherein, U type pipe includes two main pipeline sections and a bend pipe section, and the equal opening setting of first end of two main pipeline sections, the second end of two main pipeline sections is through the bend pipe section intercommunication, and the back flow setting is between the middle part of two main pipeline sections, and communicates two main pipeline sections. This application can reduce temperature and oxygen concentration in the gas section through the flue gas backward flow, increases combustion time, improves the temperature homogeneity of flue gas, reduces NOx's production, reduces the concentration of NOx in the radiant tube exhaust flue gas.

Description

Heat treatment furnace

Technical Field

The application belongs to the technical field of heat treatment furnaces, and particularly relates to a heat treatment furnace.

Background

In the related art, a U-shaped radiant tube is generally arranged in a heat treatment furnace for heating, heat energy generated by combustion of combustible gas in the U-shaped radiant tube is radiated into the heat treatment furnace, and when the combustible gas is combusted in the U-shaped radiant tube, excessive NOx can be generated due to uneven wall temperature distribution and higher temperature of a combustion section, so that the concentration of the NOx in flue gas exhausted by the U-shaped radiant tube exceeds the standard.

Disclosure of Invention

The technical problem that the concentration of NOx in the flue gas exhausted by the U-shaped radiant tube in the related art exceeds the standard can be solved to a certain extent at least. To this end, the present application provides a heat treatment furnace.

The technical scheme of the application is as follows:

the application provides a heat treatment furnace, which comprises a furnace body and a radiant tube arranged in the furnace body;

the radiant tube includes:

the U-shaped pipe comprises two main pipe sections and a bent pipe section, wherein first ends of the two main pipe sections are respectively provided with an opening, and second ends of the two main pipe sections are communicated through the bent pipe section;

the return pipe is arranged between the middle parts of the two main pipe sections and is communicated with the two main pipe sections;

the furnace body includes:

the first ends of the two main pipe sections penetrate through the furnace wall;

and a support member provided on an inner surface of the furnace wall, the bent pipe section being placed on the support member.

In some embodiments, the return tube is an arcuate structure with an opening toward the bend segment.

In some embodiments, the radiant tube has an overall length of 1800mm to 3600mm, the main tube section and the bend tube section have diameters of 150mm to 300mm, and the main tube section is spaced 300mm to 500mm apart.

In some embodiments, the return tube has a diameter of 80mm to 260mm and a distance from the end of the first end of the main tube segment of 500mm to 2600mm.

In some embodiments, the radius of the circular arc of the central axis of the return tube is 600mm to 900mm.

In some embodiments, the radiant tube further comprises two burners, the first ends of the two main tube sections are both provided with the burners, and a reversing valve is connected between the two burners.

In some embodiments, the reversing valve is a two-position nine-way reversing valve.

In some embodiments, the radiant tube further includes a heat accumulator, the heat accumulator is respectively disposed in the first ends of the two main tube sections, and the burner is disposed through the heat accumulator.

The embodiment of the application has at least the following beneficial effects:

the utility model provides a heat treatment furnace, including the radiant tube, one is responsible for the section as the burning section with the U type pipe of radiant tube, another is responsible for the section and is regarded as the exhaust section, carry combustible gas in to the burning section and burn, the flue gas that the combustible gas in the section of being responsible for burns and form can flow through the bend section, enter into in the exhaust section, because the back flow intercommunication is between two sections of being responsible for, under the effect of negative pressure, flue gas in the exhaust section can flow back to the gas section, thereby reduce temperature and oxygen concentration in the gas section, increase burning time, improve the wall temperature homogeneity of radiant tube, reduce NOx's production, reduce the concentration of NOx in the radiant tube exhaust flue gas.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic view of a heat treatment furnace according to an embodiment of the present application.

Reference numerals:

100-radiant tubes; 110-U-shaped tube; 111-main pipe section; 112-bend section; 120-return pipe; 130-burner; 140-reversing valve; 150-a heat accumulator; 200-furnace body; 210-furnace wall; 220-support.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Furthermore, the present application may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not in themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art may recognize the application of other processes and/or the use of other materials.

The present application is described below with reference to specific embodiments in conjunction with the accompanying drawings:

fig. 1 is a schematic structural diagram of a heat treatment furnace according to an embodiment of the present application, and referring to fig. 1, the heat treatment furnace includes a radiant tube 100, the radiant tube 100 includes a U-shaped tube 110 and a return tube 120, wherein the U-shaped tube 110 includes two main tube sections 111 and a curved tube section 112, first ends of the two main tube sections 111 are all open, second ends of the two main tube sections 111 are communicated through the curved tube section 112, the return tube 120 is disposed between middle portions of the two main tube sections 111, and communicates the two main tube sections 111.

Specifically, one main pipe section 111 of the U-shaped pipe 110 of the radiant tube 100 is used as a combustion section, the other main pipe section 111 is used as an exhaust section, combustible gas is conveyed into the combustion section and combusted, smoke generated by combustion of the combustible gas in the main pipe section 111 flows through the bent pipe section 112 and enters the exhaust section, and the smoke in the exhaust section flows back to the gas section under the action of negative pressure due to the fact that the return pipe 120 is communicated between the two main pipe sections 111, so that the temperature and the oxygen concentration in the gas section are reduced, the combustion time is prolonged, the wall temperature uniformity of the radiant tube 100 is improved, the generation of NOx is reduced, and the concentration of NOx in the smoke discharged by the radiant tube 100 is reduced.

In some embodiments, the arc-shaped structure of the return pipe 120, the opening of the arc-shaped structure faces the bend pipe segment 112, and the structure of the return pipe 120 is set to be arc-shaped, so as to be beneficial to the return of the flue gas, of course, the return pipe 120 may also be set to be a straight pipe, and the return of the flue gas can also be realized, which is not limited in this embodiment.

In some embodiments, the radius of the circular arc of the central axis of return tube 120 is 600mm to 900mm to ensure the return effect of return tube 120 through the curvature.

In some embodiments, the overall length of the radiant tube 100 is 1800 mm-3600 mm, the diameters of the main tube section 111 and the bent tube section 112 are 150 mm-300 mm, the distance between the two main tubes is 300 mm-500 mm, and the main body of the radiant tube 100 is arranged in the size range, so that the radiant heating effect of the radiant tube 100 is ensured.

In some embodiments, the diameter of the return tube 120 is 80 mm-260 mm, and the distance between the return tube 120 and the end of the first end of the main tube is 500 mm-2600 mm, and the return tube 120 of the radiant tube 100 is arranged in this size range, so as to ensure the return effect of the flue gas in the return tube 120.

In some embodiments, the radiant tube 100 further comprises two burners 130, the first ends of the two main tube sections 111 each being provided with a burner 130, a reversing valve 140 being connected between the two burners 130. When one burner 130 performs combustion operation, the main pipe section 111 where the burner 130 is located is used as a combustion section, the other burner 130 stops combustion operation, the main pipe section 111 where the burner 130 is located is an exhaust section, and flue gas stores heat of the burner 130 located in the exhaust section, so that the use efficiency of heat energy is improved, and the emission of NOx is reduced.

In some embodiments, the reversing valve 140 is a two-position nine-way reversing valve 140, and since the radiant tube 100 is provided with two burners 130, the working states of the two burners 130 need to be switched by the reversing valve 140, and each burner 130 needs to be connected with a gas pipeline, an air supply pipeline, an air exhaust pipeline, etc., the gas pipeline, the air supply pipeline, the air exhaust pipeline, etc. are connected with the reversing valve 140, and the switching connection between the pipelines is realized by the reversing valve 140.

In some embodiments, the radiant tube 100 further includes a heat accumulator 150, the heat accumulator 150 is disposed in the first ends of the two main tube sections 111, and the burner 130 is disposed through the heat accumulator 150, so that the heat accumulator 150 stores heat, and the heat accumulator 150 stores heat for the burner 130 to perform combustion operation, and preheats the gas entering the burner 130.

On the other hand, the application also provides a heat treatment furnace, which comprises the radiant tube 100, wherein the radiant tube 100 is arranged in the furnace body 200 of the heat treatment furnace, and the first ends of the two main tube sections 111 are penetrated on the furnace wall 210 of the furnace body 200, so that the radiant tube 100 is fixed in the furnace body 200. The support 220 is provided on the inner surface of the furnace wall 210 of the furnace body 200, the bent pipe section 112 is placed on the support 220, the combustion operation is performed on the radiant tube 100, mainly, the portion of the radiant tube 100 located in the furnace body 200 generates heat, the radiant tube 100 of the portion expands due to the heat generation, so that the portion of the radiant tube 100 located in the furnace body 200 is a free end, and the support 220 on the furnace wall 210 only plays a supporting role.

In some embodiments, the end of the first end of the two main pipe sections 111 is provided with a flange, the radiant tube 100 is connected with the outer surface of the furnace wall 210 through the flange on the main pipe section 111, a sealing heat insulation material is filled between the peripheral surface of the first end of the main pipe section 111 and the furnace wall 210, the first end of the burner 130 is a nozzle, the second end of the burner 130 is provided with a flange, the first end of the burner 130 is arranged in the main pipe section 111, the flange of the second end of the burner 130 is connected with the flange of the first end of the main pipe section 111, and a sealing gasket is arranged between the flange of the second end of the burner 130 and the flange of the first end of the main pipe section 111 to improve the sealing effect, so that the integral structure of the heat treatment furnace is realized.

Through experimental detection, the concentration of NOx in the exhaust flue gas of the heat treatment furnace provided by the embodiment of the application is as follows: at the temperature of 700 ℃, the NOx emission value is less than or equal to 60mg/m ³ NOx emission value (133 mg/m) ³ Left and right); at the temperature of 900 ℃, the NOx emission value is less than or equal to 90mg/m ³ NOx emission value (210 mg/m) ³ ) Left and right.

In this application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, and may also include the first and second features not being in direct contact but being in contact with each other by way of additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

In the description of the present application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise" indicate or positional relationships are based on the positional relationships shown in the drawings, merely for convenience of description and to simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

It should be noted that all the directional indicators in the embodiments of the present application are only used to explain the relative positional relationship, movement conditions, etc. between the components in a specific posture, and if the specific posture is changed, the directional indicators are correspondingly changed.

In the present application, unless explicitly specified and limited otherwise, the terms "coupled," "secured," and the like are to be construed broadly, and for example, "secured" may be either permanently attached or removably attached, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In addition, descriptions such as those related to "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated in this application. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Further, one skilled in the art can engage and combine the different embodiments or examples described in this specification.

In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be regarded as not exist and not within the protection scope of the present application.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.

Claims

1. A heat treatment furnace, which is characterized by comprising a furnace body and a radiant tube arranged in the furnace body;

the radiant tube includes:

the overall length of the radiant tube is 1800-3600 mm, the diameters of the main tube section and the bent tube section are 150-300 mm, the distance between the two main tube sections is 300-500 mm, the diameter of the return tube is 80-260 mm, and the distance between the return tube and the end part of the first end of the main tube section is 500-2600 mm;

the furnace body includes:

2. The heat treatment furnace according to claim 1, wherein the return pipe has an arc-shaped structure, and an opening of the arc-shaped structure is directed toward the bend section.

3. The heat treatment furnace according to claim 2, wherein the radius of the circular arc of the central axis of the return pipe is 600mm to 900mm.

4. A heat treatment furnace according to any one of claims 1 to 3, wherein the radiant tube further comprises two burners, the burners being provided at a first end of both of the main tube sections, a reversing valve being connected between the two burners.

5. The heat treatment furnace according to claim 4, wherein the reversing valve is a two-position nine-way reversing valve.

6. The heat treatment furnace according to claim 4, wherein the radiant tube further comprises a heat accumulator, the heat accumulator is disposed in the first ends of the two main tube sections, respectively, and the burner is disposed through the heat accumulator.