Internal and external crossed heat exchange assembly, heat exchange device and sintering ignition furnace

Abstract

The utility model discloses an internal and external crossed heat exchange assembly, a heat exchange device and a sintering ignition furnace, and belongs to the technical field of sintering. The internal and external crossed heat exchange assembly comprises a plurality of first heat exchange matrixes and second heat exchange matrixes which are sequentially distributed in the heat reduction direction of the hot gas channel and are connected and communicated with the cold gas channel, and the first heat exchange matrixes and the second heat exchange matrixes each comprise a heat exchange pipe and an eduction pipe. Wherein at least part of the eduction tube is provided with a flat open tube tail and extends into the heat exchange tube with the arc-shaped closed tube tail, and a gap is formed between the flat open tube tail and the arc-shaped closed tube tail. The heat exchange device is arranged above the heat preservation section of the sintering ignition furnace, radiant heat generated by the material surface of the heat preservation section is effectively utilized for preheating, and energy waste is reduced; and meanwhile, the charge level is subjected to heat preservation, so that cold brittleness of the sinter caused by sharp drop of the surface layer temperature can be avoided, the problem of hot brittleness caused by shock cooling of the sinter is solved, and the charge level quality is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sintering technical field, more specifically, relate to a kind of inside and outside cross type heat exchange assembly, heat exchange device and sintering firing furnace. BACKGROUND

[0002] Sintering is an important part of metallurgical industry, especially steel smelting process, and is also one of the key operations affecting the energy consumption index of the whole smelting process. Sintering is a processing method to provide "fine material" for blast furnace smelting. Its essence is to mix and granulate the prepared various raw materials (concentrate, ore powder, fuel, solvent, returned ore, etc.) in a certain proportion to obtain sintered material meeting the requirements. The sintered material is ignited by the combustion of carbon and oxidation of iron ore to generate high temperature, which softens and melts part of the components in the sintered material, and chemical reactions occur to generate a certain amount of liquid phase. When cooled, they are bonded together to form a block. The product of this process is called sintered ore.

[0003] A firing furnace is needed during sintering process. The firing furnace plays a role in sintering ignition and achieving hot air sintering during ore sintering production process. Its ignition temperature range is usually 1100-1300℃, and it is usually controlled at 1150±50℃ in actual operation. In the fire section of the firing furnace, air, gas or other gases need to be introduced. These gases are generally heated by heat exchange before being burned, which can improve the efficiency of combustion. Therefore, before air, gas or other gases enter the firing furnace, they are exchanged through heat exchange pipes. At present, a preheater is provided in the heat preservation section of the firing furnace. On the one hand, the preheated air and gas can increase the theoretical combustion temperature of the fuel, and on the other hand, it can recover part of the heat and save energy. With the promotion of the "double carbon" policy, the total CO2 emission of flue gas is also required to be reduced, so energy saving is of great significance.

[0004] In order to solve the above problems, through retrieval, for example, Chinese patent CN217953236U discloses a radiation heat transfer type heat pipe heat exchanger, a plurality of stainless steel pipes are provided in the sintering heat preservation section. However, the structure disclosed in the patent can preheat the combustion-supporting air or gas to 180-200℃ using the radiant heat of the sintered material surface. However, due to the large airflow, the preheating efficiency is not high. SUMMARY

[0005] 1. Problem to be solved

[0006] In view of the problem of low preheating efficiency in the prior art, the first purpose of the utility model is to provide an inside and outside cross type heat exchange assembly, which reduces the airflow speed and improves the heat exchange efficiency.

[0007] The second purpose of the utility model is to provide a heat exchange device with the inside and outside cross type heat exchange assembly of the first aspect.

[0008] The third purpose of the utility model is to provide a sintering ignition furnace with the heat exchange device of the second aspect.

[0009] 2, technical scheme

[0010] To solve the above problems, the utility model adopts the following technical scheme.

[0011] The utility model discloses a first aspect provides a kind of inside and outside cross type heat exchange assembly, connect between hot gas passage and cold gas passage, the hot gas passage and cold gas passage are separately arranged, for using the heat of hot gas to heat cold gas;It includes the first heat exchange matrix and second heat exchange matrix of several connection intercommunication cold gas passage in turn distribution along the direction of heat reduction of hot gas passage, the first heat exchange matrix and second heat exchange matrix all include heat exchange pipe and lead-out pipe, wherein at least part of the lead-out pipe has flat open pipe tail and is inserted into the heat exchange pipe with arc closed pipe tail, and gap is formed between the flat open pipe tail and arc closed pipe tail.Air and / or gas enter the first heat exchange matrix and second heat exchange matrix from cold gas passage, high-temperature gas transfers heat to heat exchange pipe by heat transfer and heat radiation, then heats the air / or gas entering heat exchange pipe, can preheat air / or gas about 20 DEG C to 100 DEG C or so, not only can reduce air, gas consumption, but also air preheating can improve the combustion temperature of fuel, thereby improving the production capacity of sintering ignition furnace.

[0012] Need to be explained is, the structure design of the utility model, adopt the double-layered heat exchange structure of lead-out pipe and heat exchange pipe, effectively increases the operating resistance of cold gas, to realize reducing air flow velocity, improve heat exchange efficiency.

[0013] According to any embodiment of the first aspect of the utility model, the material of the lead-out pipe and the heat exchange pipe is different, for example, the material of the lead-out pipe is Q235, and the material of the heat exchange pipe is stainless steel, wherein the lead-out pipe has good high-temperature resistance and wear resistance, the heat exchange pipe contacts with high-temperature flue gas, has high-temperature resistance and is not easy to deform, and has long service life.

[0014] According to any embodiment of the first aspect of the utility model, the material of the heat exchange pipe of the first heat exchange matrix near the front end of the hot gas passage is Cr25Ni20, and the material of the heat exchange pipe of the second heat exchange matrix near the rear end of the hot gas passage is 1Cr18Ni9Ti.

[0015] According to any embodiment of the first aspect of the utility model purposes, the pipe diameter ratio of the lead-out pipe and the heat exchange pipe is 1:1.5-2;And / or, the pipe wall thickness of the lead-out pipe and the heat exchange pipe is same or different, preferably, the pipe wall thickness of the lead-out pipe and the heat exchange pipe is 4mm;Or, the pipe wall thickness of the lead-out pipe is 4mm, and the pipe wall thickness of the heat exchange pipe is 6mm.

[0016] According to any embodiment of the first aspect of the utility model purposes, at least part of the lead-out pipe and the heat exchange pipe are coaxially distributed in the longitudinal direction.

[0017] The utility model discloses a second aspect provides a kind of heat exchange device, including roof, side plate, first baffle and second baffle and by roof, side plate, first baffle and second baffle connection constitute cold gas passage and hot gas passage, the cold gas passage includes air inlet passage and air outlet passage, the air inlet passage is connected and communicated first reducing pipe and first spiral pipe, the air outlet passage is connected and communicated second reducing pipe and second spiral pipe, further include the inside-out cross type heat exchange component connected between hot gas passage and cold gas passage, the hot gas passage is separately arranged with cold gas passage, the inside-out cross type heat exchange component includes the first heat exchange matrix and second heat exchange matrix that are connected and communicated cold gas passage in turn along the direction of heat reduction of hot gas passage, the first heat exchange matrix and second heat exchange matrix all include heat exchange pipe and lead-out pipe, wherein at least part of the lead-out pipe has flat open pipe tail and is inserted into the heat exchange pipe with arc closed pipe tail, and gap is formed between the flat open pipe tail and arc closed pipe tail.

[0018] According to any embodiment of the second aspect of the utility model purposes, the heat exchange pipe longitudinal section shape is U-shaped, and its open end is connected and communicated the air inlet passage;The lead-out pipe longitudinal section shape is square, and its open end is connected and communicated the air outlet passage.

[0019] According to any embodiment of the second aspect of the utility model purposes, the underside of the roof is provided with a heat preservation layer, and the material of the heat preservation layer is aluminum silicate fiber cotton;And / or, a hanging plate is arranged on the underside of the roof.

[0020] According to any embodiment of the second aspect of the utility model purposes, a pull rod is arranged between the roof and the first baffle and the second baffle.

[0021] The utility model discloses a third aspect provides a kind of sintering ignition furnace, including sintering ignition furnace body and with the heat exchange device of second aspect, the heat exchange device is connected on sintering ignition furnace body.

[0022] 3, beneficial effects

[0023] Compared with prior art, the beneficial effects of the utility model are:

[0024] (1) The inner-outer cross heat exchange assembly of the utility model adopts the double-layered heat exchange structure of the lead-out pipe and the heat exchange pipe, effectively increases the operation resistance of the cold gas, thereby realizing the reduction of the airflow flow speed, improving the heat exchange efficiency; effectively utilizes the radiation heat generated by the material surface of the heat preservation section for preheating, reduces the waste of energy; at the same time, the material surface is heat preserved, the sintering "cold brittleness" caused by the sharp drop of the surface temperature can be avoided, the problem of the hot brittleness caused by the rapid cooling of the sintering is solved, and the material surface quality is improved;

[0025] (2) The heat exchange device of the utility model is arranged above the heat preservation section, when the high-temperature material surface passes through the bottom of the heat exchange device, the high-temperature material surface transmits heat to the heat exchange pipe through the convection and radiation heat transfer, after the heat transfer of the heat conduction of the heat exchange pipe, the heat is transmitted to the preheated cold gas through the convection, the radiation heat of the sintering material surface can preheat the combustion-supporting air to about 100 DEG C, thereby saving the fuel;

[0026] (3) The heat exchange device of the utility model, for the ignition furnace using low-calorific value gas, preheating the air and the gas becomes a necessary prerequisite, otherwise the furnace temperature required by the process cannot be reached. BRIEF DESCRIPTION OF DRAWINGS

[0027] The technical scheme of the utility model will be further described in detail below in combination with the drawings and embodiments, but it should be known that these drawings are only designed for the purpose of explanation, thus not as the limitation of the range of the utility model. In addition, unless particularly pointed out, these drawings only intend to conceptually illustrate the structural configuration described herein, and are not necessarily drawn according to the scale.

[0028] Figure 1 It is the structure schematic view of the heat exchange device of the utility model;

[0029] Figure 2 It is Figure 1 The sectional view along A-A line;

[0030] Figure 3 It is Figure 1 The sectional view along B-B line;

[0031] Figure 4 It is the sectional structure schematic view of the heat exchange device of the utility model;

[0032] Figure 5 It is Figure 2 The enlarged view of C part.

[0033] Explanation of reference signs:

[0034] 11, top plate; 111, insulation layer; 112, hanging plate; 113, pull rod; 12, side plate; 13, first partition plate; 14, second partition plate; 15, hot gas passage; 16, cold gas passage; 161, gas inlet passage; 162, gas outlet passage; 163, first reducing pipe; 164, first spiral pipe; 165, second reducing pipe; 166, second spiral pipe; 17, inner-outer cross heat exchange assembly; 171, first heat exchange matrix; 172, second heat exchange matrix; 173, heat exchange pipe; 174, lead-out pipe; 175, shock-absorbing protrusion. DETAILED DESCRIPTION

[0035] The present disclosure can be more easily understood and further advantages and benefits can be obtained by reference to the following description and examples in conjunction with the accompanying drawings, in which all figures are schematic, like elements are referred to with like reference numerals, and in which: It should be understood that the present disclosure is not limited to the particular products, methods, conditions or parameters described and / or shown herein, unless otherwise specified. Further, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, unless otherwise specified.

[0036] It should also be understood that, for clarity, certain features of the present disclosure can be described in the context of separate embodiments, but can also be provided in combination in a single embodiment. That is, unless explicitly stated otherwise, each separate embodiment is considered to be combinable with any other embodiment, and such combinations are considered to represent another, different embodiment. Conversely, various features of the present disclosure described in the context of a single embodiment can also be provided separately or in any sub-combination, for the sake of conciseness. Finally, while a particular embodiment can be described as part of a series of steps or part of a more general structure, each step or sub-structure can also be considered an independent embodiment.

[0037] Unless otherwise stated, it is to be understood that each individual element in a list and each combination of individual elements in a list are to be construed as a separate embodiment. For example, a list of embodiments recited as “A, B, or C” is to be construed as including the embodiments of “A,” “B,” “C,” “A or B,” “A or C,” “B or C,” or “A, B, or C.”

[0038] In this disclosure, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a substance” is a reference to at least one of such a substance and equivalents thereof.

[0039] Terms including ordinal numbers such as "first" and "second" can be used to explain various components or fluids, but the components, fluids are not limited by the terms. Therefore, the terms are used only to distinguish the component / fluid from another component / fluid without departing from the teachings of the present disclosure.

[0040] When items are described using conjunctive terms such as "and / or", the description should be understood to include any one of the associated listed items and all combinations of one or more of them.

[0041] In general, the use of the term "about" indicates an approximation that can vary depending on the desired characteristics obtained by the disclosed subject matter, and will be interpreted functionally in a context-dependent manner. Therefore, a person of ordinary skill in the art will be able to interpret a certain degree of difference on a case-by-case basis. In some cases, the number of significant digits used in expressing a particular value can be representative of the degree of precision to which the term "about" allows for variation. In other cases, a range of values in a series of values can be used to determine the range of variation allowed by the term "about". Further, all ranges in the present disclosure are inclusive and combinable, and the mention of a value stated in a range includes every value within the range.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used herein and / or any and all combinations of one or more related listed items.

[0043] The sintering ignition furnace of the present application comprises a sintering ignition furnace body and a heat exchange device, and the heat exchange device is connected to the body of the sintering ignition furnace heat preservation section.

[0044] As shown in Figures 1 to 5 The heat exchange device of the present embodiment comprises a top plate 11, a side plate 12, a first partition plate 13, a second partition plate 14, an inside-out cross heat exchange assembly 17, and a cold gas passage 16 and a hot gas passage 15 connected and composed of the top plate 11, the side plate 12, the first partition plate 13 and the second partition plate 14. The cold gas passage 16 comprises an air inlet passage 161 and an air outlet passage 162. The air inlet passage 161 is connected and communicated with a first reducing pipe 163 and a first spiral pipe 164. The air outlet passage 162 is connected and communicated with a second reducing pipe 165 and a second spiral pipe 166. The material of the first reducing pipe 163 is 1Cr18Ni9Ti; the materials of the first spiral pipe 164, the second reducing pipe 165 and the second spiral pipe 166 are Q235.

[0045] In combination Figure 2 And Figure 3As shown, the arrows in the figure indicate the direction of travel of the cold gas, and the internal and external cross-type heat exchange component 17 is connected between the hot gas channel 15 and the cold gas channel 16, and the hot gas channel 15 is separated from the cold gas channel 16. The internal and external cross-type heat exchange component 17 includes a first heat exchange matrix 171 and a second heat exchange matrix 172 that are sequentially distributed along the direction of heat reduction of the hot gas channel 15 and connected to the cold gas channel 16. The first heat exchange matrix 171 and the second heat exchange matrix 172 both include heat exchange tubes 173 and outlet tubes 174, wherein at least part of the outlet tubes 174 have flat open tube tails and extend into the heat exchange tubes 173 with arc-shaped closed tube tails, and a gap is formed between the flat open tube tail and the arc-shaped closed tube tail, and the gap can provide a channel for the preheated cold gas to enter the outlet tube 174.

[0046] Air and / or coal gas enter the first heat exchange matrix 171 and the second heat exchange matrix 172 through the cold gas channel 16. The high-temperature gas from the ignition section transfers heat to the heat exchange tube 173 through heat conduction and heat radiation, and then heats the air / or coal gas entering the heat exchange tube 173. The air / or coal gas at about 20°C can be preheated to about 100°C, which not only reduces the consumption of air and gas, but also increases the combustion temperature of the fuel after the air is preheated, thereby improving the production capacity of the sintering ignition furnace.

[0047] It should be noted that the structural design of the present invention utilizes a double-layered heat exchange structure, with the outlet tube 174 and the heat exchange tube 173 being nested together. This effectively increases the resistance to the cold gas flow, thereby reducing the airflow velocity and improving heat exchange efficiency. To reduce resonance in the heat exchange tube 173 caused by reduced flow velocity, vibration-damping protrusions 175 are evenly distributed on the inner wall of the heat exchange tube 173.

[0048] In this embodiment, if Figure 4 As shown, to further improve heat exchange efficiency, at least a portion of the outlet tube 174 is longitudinally coaxially arranged with the heat exchange tube 173. Furthermore, the heat exchange tube 173 has a U-shaped longitudinal cross-section, with its open end connected to the air inlet passage 161. The outlet tube 174 has a square longitudinal cross-section, with its open end connected to the air outlet passage 162.

[0049] exist Figure 2 and Figure 3 In the embodiment, the lower side of the top plate 11 is provided with an insulation layer 111 made of aluminum silicate fiber cotton; and / or, a hanging plate 112 is provided on the lower side of the top plate 11. Tie rods 113 are provided between the top plate 11 and the first and second partitions 13, 14. The hanging plate 112, top plate 11, first and second partitions 13, 14, and tie rods 113 are all made of Q235, while the side plates 12 are made of Cr25Ni20.

[0050] Further, the material of the export pipe 174 is different from that of the heat exchange pipe 173, for example, the material of the export pipe 174 is Q235, and the material of the heat exchange pipe 173 is stainless steel, wherein the export pipe 174 has better high-temperature resistance and wear resistance, the heat exchange pipe 173 is in contact with high-temperature flue gas, has high-temperature resistance and is not easy to deform, and has long service life.

[0051] In order to improve the service life of the heat exchange device, the material of the heat exchange pipe 173 of the first heat exchange matrix 171 near the front end of the hot gas passage 15 is Cr25Ni20, and the material of the heat exchange pipe 173 of the second heat exchange matrix 172 near the rear end of the hot gas passage 15 is 1Cr18Ni9Ti, both of which are commercially available stainless steel materials and have high thermal conductivity.

[0052] In the embodiment, the pipe diameter ratio of the export pipe 174 to the heat exchange pipe 173 is 1:1.5. The pipe wall thickness of the export pipe 174 and the heat exchange pipe 173 is the same or different, preferably, the pipe wall thickness of the export pipe 174 and the heat exchange pipe 173 is 4mm; or the pipe wall thickness of the export pipe 174 is 4mm, and the pipe wall thickness of the heat exchange pipe 173 is 6mm.

[0053] The heat exchange device of the utility model is used in practice, and the actual measured temperature of the heat preservation section of the on-site ignition furnace is about 350-400℃, the outlet temperature of the coal gas is 100℃, the inlet temperature is 20℃, and the temperature efficiency is (100-20) / 400=20%.

[0054] Air and coal gas preheating can reduce coal gas consumption, and air preheating can increase the theoretical combustion temperature of fuel. Generally, the theoretical combustion temperature can be increased by about 50℃ for every 100℃ increase in air preheating temperature, thereby increasing the production capacity of the sintering ignition furnace. According to experience, the production capacity of the sintering ignition furnace can be increased by about 2% for every 100℃ increase in preheating temperature. If the preheating temperature of the coal gas or air is increased by 100℃, the fuel can be saved by 3%-4%.

[0055] It is obvious for those skilled in the art that the utility model is not limited to the details of the above-mentioned exemplary embodiments, and can be realized in other specific forms without departing from the spirit or basic characteristics of the utility model. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, the scope of the utility model is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the utility model. Any reference signs in the claims should not be regarded as limiting the involved claims.

Claims

1. An inner-outer cross heat exchange assembly (17) connected between a hot gas passage (15) and a cold gas passage (16) which are arranged to be separated from each other for heating the cold gas by using the heat of the hot gas; characterized in that, The first heat exchange matrix (171) and the second heat exchange matrix (172) are arranged in sequence along the direction of heat reduction of the hot gas passage (15) and are connected to the cold gas passage (16), and each of the first heat exchange matrix (171) and the second heat exchange matrix (172) comprises a heat exchange pipe (173) and a lead-out pipe (174), wherein at least part of the lead-out pipe (174) has a flat open pipe tail and extends into the heat exchange pipe (173) with an arc-shaped closed pipe tail, and a gap is formed between the flat open pipe tail and the arc-shaped closed pipe tail.

2. The cross-counterflow heat exchanger package (17) according to claim 1, characterized in that The material of the lead-out pipe (174) is different from that of the heat exchange pipe (173).

3. The cross-counterflow heat exchanger package (17) according to claim 2, characterized in that The material of the heat exchange pipe (173) of the first heat exchange matrix (171) near the front end of the hot gas passage (15) is Cr25Ni20, and the material of the heat exchange pipe (173) of the second heat exchange matrix (172) near the rear end of the hot gas passage (15) is 1Cr18Ni9Ti.

4. The cross-counterflow heat exchanger package (17) according to claim 3, characterized in that The ratio of the pipe diameter of the lead-out pipe (174) to the heat exchange pipe (173) is 1:1.5-2; and / or, the pipe wall thickness of the lead-out pipe (174) is the same as or different from that of the heat exchange pipe (173).

5. The cross-counterflow heat exchanger package (17) according to claim 4, characterized in that At least part of the lead-out pipe (174) and the heat exchange pipe (173) are coaxially arranged in the longitudinal direction.

6. A heat exchange device comprising a top plate (11), a side plate (12), a first partition plate (13) and a second partition plate (14), and a cold gas passage (16) and a hot gas passage (15) formed by the top plate (11), the side plate (12), the first partition plate (13) and the second partition plate (14), the cold gas passage (16) comprising an inlet passage (161) and an outlet passage (162), the inlet passage (161) being connected to a first reducing pipe (163) and a first spiral pipe (164), the outlet passage (162) being connected to a second reducing pipe (165) and a second spiral pipe (166), characterized in that, The heat exchange device further comprises an inner-outer cross heat exchange assembly (17) connected between the hot gas passage (15) and the cold gas passage (16), wherein the hot gas passage (15) and the cold gas passage (16) are arranged separately, and the inner-outer cross heat exchange assembly (17) comprises a first heat exchange matrix (171) and a second heat exchange matrix (172) arranged in sequence along the direction of heat reduction of the hot gas passage (15) and connected to the cold gas passage (16), and each of the first heat exchange matrix (171) and the second heat exchange matrix (172) comprises a heat exchange pipe (173) and a lead-out pipe (174), wherein at least part of the lead-out pipe (174) has a flat open pipe tail and extends into the heat exchange pipe (173) with an arc-shaped closed pipe tail, and a gap is formed between the flat open pipe tail and the arc-shaped closed pipe tail.

7. The heat exchange device according to claim 6, wherein The longitudinal section shape of the heat exchange pipe (173) is U-shaped, and the open end thereof is connected to the gas inlet passage (161); and the longitudinal section shape of the lead-out pipe (174) is square, and the open end thereof is connected to the gas outlet passage (162).

8. The heat exchange device according to claim 7, wherein The lower side of the top plate (11) is provided with a heat preservation layer (111), and the material of the heat preservation layer (111) is aluminum silicate fiber cotton; and / or, a hanging plate (112) is arranged on the lower side of the top plate (11).

9. The heat exchange device according to claim 8, wherein A pull rod (113) is arranged between the top plate (11) and the first partition plate (13) and the second partition plate (14).

10. A sintering ignition furnace comprising a sintering ignition furnace body, characterized by The heat exchange device of any one of claims 6-9 is further connected to the sintering ignition furnace body.

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