CN116242143A

CN116242143A - Tubular heating furnace

Info

Publication number: CN116242143A
Application number: CN202310313808.4A
Authority: CN
Inventors: 赖银飞; 刘剑
Original assignee: Shanghai Xtek Furnace Co ltd
Current assignee: Shanghai Xtek Furnace Co ltd
Priority date: 2023-03-28
Filing date: 2023-03-28
Publication date: 2023-06-09

Abstract

The application discloses tubular heating furnace, it includes: the radiation chamber comprises a bottom wall, a top wall, side walls and a furnace tube, wherein the bottom wall, the top wall and the side walls jointly form an accommodating space, and the furnace tube is positioned in the accommodating space; the burner is positioned in the middle of the bottom wall and/or the top wall, and the furnace tube is positioned between the flame generated by the burner and the side wall; a fuel gas injection pipe provided on at least one of the bottom wall, the top wall, and the side wall for injecting fuel gas into the accommodation space between the furnace tube and the side wall; and the convection chamber is arranged at the top of the radiation chamber and is communicated with the accommodating space. According to the tubular heating furnace, the heat intensity of the furnace tube can be effectively improved, and the furnace tube is heated more uniformly.

Description

Tubular heating furnace

Technical Field

The application relates to the technical field of petrochemical industry, in particular to a tubular heating furnace.

Background

The tubular heating furnace is used in oil refining, chemical industry, oil field, long pipeline and other industry. The tube heating furnace generally comprises a radiation chamber, a convection chamber, a burner, a waste heat recovery system, a smoke duct system and the like.

For a furnace type with a simple structure such as a cylindrical furnace, the burner is usually arranged on one side of the furnace tube away from the side wall, the heat transfer intensity of one side of the furnace tube away from the burner is poor, and the furnace tube has the problems of uneven heating along the circumferential direction, low average heat intensity, low effective utilization rate of the furnace tube and serious waste of heat transfer area of the furnace tube.

There is therefore a need for an improvement to at least partially solve the above-mentioned problems.

Disclosure of Invention

In the summary, a series of concepts in a simplified form are introduced, which will be further described in detail in the detailed description. The summary of the invention is not intended to define the key features and essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In order to solve the above problems at least in part, the present invention provides a tube heating furnace comprising:

the radiation chamber comprises a bottom wall, a top wall, side walls and a furnace tube, wherein the bottom wall, the top wall and the side walls jointly form an accommodating space, and the furnace tube is positioned in the accommodating space;

the burner is positioned in the middle of the bottom wall and/or the top wall, and the furnace tube is positioned between the flame generated by the burner and the side wall;

a fuel gas injection pipe provided on at least one of the bottom wall, the top wall, and the side wall for injecting fuel gas into the accommodation space between the furnace tube and the side wall;

and the convection chamber is arranged at the top of the radiation chamber and is communicated with the accommodating space.

Illustratively, at least one of the bottom wall, the top wall, and the side wall is provided with a pre-shrinking and post-enlarging flow passage at a position corresponding to the fuel gas nozzle, and the flow area of the pre-shrinking and post-enlarging flow passage is gradually reduced and then gradually increased.

Illustratively, the bottom wall, the top wall, and the inner side of the side wall are each provided with a refractory lining in which the pre-telescoping, post-telescoping flow path is located.

Illustratively, the fuel gas injection lance comprises a fuel gas inlet pipe provided with a control valve and a flame arrester.

Illustratively, the tubular furnace further comprises a flammable gas analyzer disposed on the top wall and/or in the convection chamber.

Illustratively, the tubular furnace further comprises a first controller coupled to the combustible gas analyzer, the burner, and the fuel gas lance.

Illustratively, the tubular heating furnace further comprises a temperature sensor disposed on at least one of the bottom wall, the implementation side wall, and the top wall for detecting a furnace temperature and/or a temperature of the furnace tube.

Illustratively, the tubular furnace further includes a second controller coupled to the temperature sensor, the burner, and the fuel gas injection tube.

Illustratively, the furnace tube is a riser, a sleeper tube, or a spiral tube.

Illustratively, the radiation chamber is cylindrical or square box shaped.

According to the tubular heating furnace disclosed by the invention, the fuel gas is injected into the accommodating space between the furnace tube and the side wall through the fuel gas spray tube, so that the fuel gas can be flamelessly combusted in the accommodating space between the furnace tube and the side wall, the furnace tube is heated on the side, far away from the burner, of the furnace tube, the furnace tube is heated uniformly, the average heat intensity is high, the effective utilization rate of the furnace tube is high, the heat transfer area of the furnace tube is effectively utilized, and the emission of NOx can be reduced to a certain extent due to the arrangement of the fuel gas spray tube.

Drawings

The following drawings of the present application are included to provide an understanding of the present application as part of the present application. The drawings illustrate embodiments of the present application and their description to explain the principles and devices of the present application. In the drawings of which there are shown,

FIG. 1 is a schematic view of a tube furnace according to an embodiment of the present application;

fig. 2 is a schematic diagram of a first-shrink and second-expansion structure.

Reference numerals illustrate:

100-radiation chamber, 110-bottom wall, 120-top wall, 130-side wall, 140-furnace tube, 150, 160, 170-refractory lining, 151-pre-shrinking and post-expanding runner, 200-burner, 300-fuel gas jet tube, 310-jet nozzle, 400-convection chamber, 500-flue.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application may be practiced without one or more of these details. In other instances, some features well known in the art have not been described in order to avoid obscuring the present application.

It should be understood that the present application may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. In the drawings, the size of layers and regions, as well as the relative sizes, may be exaggerated for clarity. Like numbers refer to like elements throughout.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application.

Spatially relative terms, such as "under," "below," "beneath," "under," "above," "over," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and operation in addition to the orientation depicted in the figures.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

Embodiments of the invention are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the present application. In this way, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the present application should not be limited to the particular shapes shown herein, but rather include deviations in shapes that result, for example, from manufacturing. Thus, the illustrations shown in the figures are schematic in nature, their shapes are not intended to illustrate the actual shape of a device and are not intended to limit the scope of the present application.

A tube furnace according to an embodiment of the present application is exemplarily described with reference to fig. 1 and 2, and includes a radiation chamber 100, a burner 200, a fuel gas lance 300, and a convection chamber 400.

The radiation chamber 100 includes a bottom wall 110, a top wall 120, a side wall 130, and a furnace tube 140, where the bottom wall 110, the top wall 120, and the side wall 130 together form an accommodating space. The furnace tube 140 is located in the accommodating space, and the furnace tube 140 may be a riser, a horizontal tube or a spiral tube, and a furnace tube 140 support is disposed in the accommodating space to support and fix the furnace tube 140, and the furnace tube 140 support may be fixed to the bottom wall 110 and/or the top wall 120. A certain distance exists between the side of the furnace tube 140 facing the side wall 130 and the side wall 130, and a certain distance exists between the side of the furnace tube 140 away from the side wall 130 and the middle of the accommodating space. The radiant chamber 100 may be cylindrical or square box shaped, i.e., the tube furnace may be a cylindrical furnace or square box furnace.

In the embodiment of the present application, the burner 200 is located in the middle of the bottom wall 110, for generating a flame in the middle of the accommodating space, and the furnace tube 140 is located between the flame generated by the burner 200 and the side wall 130, that is, the burner 200 may heat the side of the furnace tube 140 away from the side wall 130 (that is, the side of the furnace tube 140 facing the middle of the accommodating space) by means of heat radiation. When the radiation chamber 100 has a cylindrical shape, the burner 200 may be provided only in one, and disposed at the middle of the bottom wall 110; the number of the burners 200 may be plural, and the burners may be annularly disposed at the middle portion of the bottom wall 110. When the radiation chamber 100 has a square box shape, the burner 200 may be linearly disposed at the middle of the bottom wall 110. In other embodiments, the burner 200 may be located in the middle of the top wall 120 for generating a flame in the middle of the receiving space by means of top firing. In other embodiments, there are at least two burners 200 located in the middle of the top wall 120 and the middle of the bottom wall 110, respectively.

In this embodiment, the fuel gas nozzle 300 is located on the bottom wall 110 between the burner tube 140 and the side wall 130, and is used for injecting fuel gas into the space between the burner tube 140 and the side wall 130 at a high speed, and when the fuel gas is injected at a high speed, the high-temperature flue gas in the accommodating space can be sucked by the sucking action of the jet flow, so that the fuel gas is fully mixed and diluted by the flue gas, and is heated to a temperature above the ignition point, meanwhile, oxygen in the high-temperature flue gas is used as an oxidant of the diluted fuel gas, so that the fuel gas is in a high-temperature low-oxygen state (the oxygen content is about 2%), and flameless heating is realized, thereby heating the burner tube 140 towards one side of the side wall 130 in a heat radiation manner. In the flameless combustion mode, the fuel gas diffuses into the space behind the burner tube 140, and the combustion is "soft" and slow, without noise, which can lead to uniform temperature distribution in the space between the burner tube 140 and the sidewall 130 and lower NOx emissions. When the radiant chamber 100 is cylindrical, the fuel gas nozzles 300 may be provided in plurality and annularly disposed on the bottom wall 110 between the furnace tube 140 and the side wall 130. When the radiant chamber 100 is square box shaped, the fuel gas lance 300 may be disposed linearly on the bottom wall 110 between the furnace tube 140 and the side wall 130. In other embodiments, the fuel gas lance 300 may be disposed on the top wall 120 between the burner tube 140 and the side wall 130 or on the side wall 130 for injecting fuel gas into the space between the burner tube 140 and the side wall 130. Through the arrangement of the fuel gas spray pipe 300, the furnace tube 140 can be heated at one side of the furnace tube 140 far away from the burner 200, so that the furnace tube 140 is heated more uniformly, the average heat intensity is higher, and the effective utilization rate of the furnace tube 140 is higher. The heat transfer area of the furnace tube 140 is effectively utilized, so that the consumption of the furnace tube 140 can be saved, and the upper limit of the operation of the heating furnace can be increased. In addition, since the volume of the fuel gas nozzle 300 is significantly smaller than that of the burner 200, it can be conveniently installed on the bottom wall 110, the top wall 120 or the side wall 130, so that for a conventional single-side radiation heating furnace with a simple structure, the fuel gas nozzle 300 can be additionally arranged to modify the heating furnace into a tube type heating furnace for application, so that the furnace tube 140 is heated more uniformly, the modification amount is small, and the modification cost is low.

In the embodiment of the present application, the bottom wall 110, the top wall 120 and the side wall 130 are all steel structures, and the inner sides of the bottom wall 110 are all provided with refractory linings, the refractory lining 150 on the inner side of the bottom wall 110 may include refractory bricks and/or refractory castable materials, the refractory lining 160 on the inner side of the side wall 130 may include refractory bricks and/or refractory castable materials, and the refractory lining 170 on the inner side of the top wall 120 may include refractory castable materials. A pre-shrinking and post-expanding runner 151 is provided in the refractory lining 150 inside the bottom wall 110 at a position corresponding to the fuel gas lance 300. Referring to fig. 2, the flow area of the pre-shrinking and post-expanding flow channel 151 is gradually decreased and then gradually increased, the nozzle 311 of the fuel gas nozzle 300 is positioned in the pre-shrinking and post-expanding flow channel 151, and the fuel gas sprayed from the nozzle 311 of the fuel gas nozzle 300 enters the space between the burner tube 140 and the sidewall 130 through the pre-shrinking and post-expanding flow channel 151. The pre-shrinking and post-enlarging flow channel 151 can enable the fuel gas to be sprayed out at a high speed, the fuel gas passes through the pre-shrinking and post-enlarging flow channel 151 and then generates high-speed jet flow, the nearby high-temperature flue gas is sucked up, the high-temperature flue gas and the fuel gas are fully mixed, the fuel gas is diluted and heated, and the fuel gas is fully diffused into the space between the furnace tube 140 and the side wall 130 so as to be combusted uniformly. In other embodiments, when fuel gas lance 300 may be positioned on top wall 120 between furnace tube 140 and side wall 130 or on side wall 130, a location corresponding to fuel gas lance 310 in refractory lining 170 inside top wall 120 or refractory lining 160 inside side wall 130 may be provided with a tapered flow channel, respectively. In other embodiments, the bottom wall 110 (or the top wall 120 or the side wall 130) may be provided with a tube having a flow passage therein that is tapered and tapered, and the nozzle 31 of the fuel gas nozzle 300 is positioned in the tube. In the embodiment of the present application, the fuel gas nozzle 300 includes a fuel gas inlet pipe, and a control valve and a flame arrester are disposed on the fuel gas inlet pipe, where the control valve is used to adjust the intake air amount of the fuel gas, and the fuel gas nozzle 300 can be closed by the control valve when the fuel gas nozzle 300 is not needed.

In the embodiment of the present application, the convection chamber 400 is disposed at the top of the radiation chamber 100 and is communicated with the accommodating space, and the high-temperature flue gas from the accommodating space enters the convection chamber 400 to exchange heat with the furnace tube 140 or other heat exchange tubes in the convection chamber 400. A flue 500 is provided at the top of the convection chamber 400, and the flue 500 may be connected to a waste heat recovery system.

In the embodiment of the present application, the tube type heating furnace further includes a flammable gas analyzer, such as an infrared flammable gas analyzer or a catalytic type flammable gas analyzer, which is disposed in the convection chamber 400 for analyzing the flammable gas component of the flue gas to determine whether the fuel gas is completely combusted. In some embodiments, the tube furnace further includes a first controller, which may be a single chip microcomputer or other suitable controller, connected to the fuel gas analyzer, the burner 200, and the fuel gas nozzle 300, for controlling the combustion conditions of the burner 200 and the fuel gas nozzle 300 (e.g., controlling by adjusting the fuel gas intake amount of the fuel gas nozzle 300, the fuel gas intake amount of the burner 200, the combustion air intake amount of the burner 200, etc.) according to the analysis results of the fuel gas analyzer, so as to fully combust the fuel gas.

In embodiments of the present application, the tube furnace further includes a temperature sensor, such as a thermocouple or other suitable temperature sensor, which may be disposed on at least one of the bottom wall 110, the top wall 120, and the side walls 130 for detecting the temperature of the furnace and/or the furnace tube 140 to determine whether the furnace temperature and/or the medium temperature within the furnace tube 140 is normal. In some embodiments, the tube furnace further includes a second controller, which may be a single-chip microcomputer or other suitable controller, connected to the temperature sensor, the burner 200, and the fuel gas nozzle 300, for controlling the combustion conditions of the burner 200 and the fuel gas nozzle 300 (e.g., controlling by adjusting the fuel gas intake of the fuel gas nozzle 300, the fuel gas intake of the burner 200, the combustion air intake of the burner 200, etc.) according to the detection results of the temperature sensor, so that the furnace temperature and/or the medium temperature in the furnace tube are in a normal range.

Although the illustrative embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the above illustrative embodiments are merely illustrative and are not intended to limit the scope of the present application thereto. Various changes and modifications may be made therein by one of ordinary skill in the art without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as set forth in the appended claims.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the present application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

Similarly, it should be appreciated that in order to streamline the application and aid in understanding one or more of the various inventive aspects, various features of the application are sometimes grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of the application. However, the method of this application should not be construed to reflect the following intent: i.e., the claimed application requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this application.

It will be understood by those skilled in the art that all of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and all of the processes or units of any method or apparatus so disclosed, may be combined in any combination, except combinations where the features are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

Furthermore, those skilled in the art will appreciate that while some embodiments described herein include some features but not others included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the present application and form different embodiments. For example, in the claims, any of the claimed embodiments may be used in any combination.

It should be noted that the above-mentioned embodiments illustrate rather than limit the application, and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims.

Claims

1. A tube furnace, comprising:

2. A tube furnace according to claim 1, wherein,

and the flow area of the pre-shrinking and post-enlarging flow channel is gradually reduced and then gradually increased.

3. A tube furnace according to claim 2, wherein,

the inner sides of the bottom wall, the top wall and the side walls are provided with refractory linings, and the pre-shrinking and post-enlarging flow channels are positioned in the refractory linings.

4. A tube furnace according to claim 1, wherein,

the fuel gas injection pipe comprises a fuel gas inlet pipe, and a control valve and a flame arrester are arranged on the fuel gas inlet pipe.

5. A tube furnace according to claim 1, wherein,

the tube heating furnace further comprises a flammable gas analyzer, and the flammable gas analyzer is arranged in the convection chamber.

6. A tube furnace according to claim 5, wherein,

the tube heating furnace further comprises a first controller, and the first controller is connected with the flammable gas analyzer, the burner and the fuel gas spraying tube.

7. A tube furnace according to claim 1, wherein,

the tubular heating furnace further comprises a temperature sensor, wherein the temperature sensor is arranged on at least one of the bottom wall, the implementation side wall and the top wall and is used for detecting the temperature of the hearth and/or the temperature of the furnace tube.

8. A tube furnace according to claim 7, wherein,

the tube heating furnace further comprises a second controller, and the second controller is connected with the temperature sensor, the burner and the fuel gas spraying tube.

9. A tube furnace according to claim 1, wherein,

the furnace tube is a vertical tube, a horizontal tube or a spiral tube.

10. A tube furnace according to claim 1, wherein,

the radiation chamber is cylindrical or square box-shaped.