Hot reflux burner for VOCs (Volatile Organic Compounds)

Abstract

The utility model relates to the technical field of combustors, in particular to a hot reflux combustor for VOCs. The hot reflux burner for the VOCs comprises a combustion stabilizing disc, a heat exchanger and a heat exchanger, wherein the combustion stabilizing disc is used for diffusing VOCs waste gas after flowing through the combustion stabilizing disc; the porous structure body is connected with an outlet of the stable combustion disc, and a catalyst made of transition metal is loaded on the porous structure body; the combustion chamber is connected with an outlet of the porous structure body, a flame gun is arranged at an outlet of the combustion chamber, and after the flame gun ignites the VOCs waste gas, generated flames can be tempered into the porous structure body so as to preheat the VOCs waste gas. According to the technical scheme, energy consumption can be reduced, and combustion efficiency and stability can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of burners, in particular to a hot reflow burner for VOCs. Background Art

[0002] VOCs (Volatile Organic Compounds) are defined as organic compounds that participate in atmospheric photochemical reactions, or organic compounds determined in accordance with relevant regulations.

[0003] In 2021, the total VOCs emissions from industrial sources in my country will be 2.079 million tons, of which VOCs emissions from the coating industry account for more than 20% of the total VOCs emissions from industrial sources. As a key source of VOCs emissions in my country, the coating industry is listed as one of the key industries for VOCs governance. The main sources of VOCs pollution emissions are the storage, transportation and use of coatings, curing agents, diluents, adhesives and cleaning agents. There are many emission processes and the collection points are widely distributed. It has the characteristics of large waste gas generation, large air volume, complex composition and large concentration fluctuations, which makes it more difficult to control. The VOCs generated by the coating industry mainly include aromatic hydrocarbons, ketones, esters and alcohol ethers. Among them, toluene, paraxylene and acetone are medium and high photochemically active VOCs, which are the main factors in the formation of near-ground atmospheric ozone. The large-scale emission of VOCs will not only bring many environmental problems, but also endanger human health and human life safety. Therefore, scientific and effective VOCs treatment and disposal technology with large air volume, complex composition and large concentration fluctuations is of vital importance to VOCs pollution control, protection and improvement of air quality. Utility Model Content

[0004] The utility model provides a hot reflow burner for VOCs, which can reduce energy consumption and improve combustion efficiency and stability.

[0005] The utility model provides a hot reflow burner for VOCs, comprising:

[0006] The combustion stabilizing plate is used to diffuse the VOCs exhaust gas after it flows through;

[0007] A porous structure connected to the outlet of the combustion stabilizing disk and loaded with a catalyst made of transition metal;

[0008] A combustion chamber is connected to the outlet of the porous structure. A flame gun is provided at the outlet of the combustion chamber. After the flame gun ignites the VOCs waste gas, the flame generated can be backfired into the porous structure to preheat the VOCs waste gas.

[0009] In one possible design, it also includes:

[0010] A preheating channel is connected to the inlet of the combustion stabilizing disk. The direction in which the VOCs waste gas flows in the preheating channel is opposite to that in the combustion stabilizing disk. The heat generated by the combustion on the surface of the porous structure can be transferred to the preheating channel to preheat the VOCs waste gas.

[0011] In one possible design, it also includes:

[0012] The pretreatment unit is connected to the inlet of the preheating channel and is used to filter dust in the VOCs exhaust gas.

[0013] In a possible design, the pretreatment unit is a fiber filter or a dry-wet composite filter.

[0014] In a possible design, the porous structure is made of silicon carbide, zirconium oxide, aluminum oxide or cordierite.

[0015] In a possible design, the porous structure is made by a hot alkali method.

[0016] In a possible design, the pore diameter of the porous structure is 1.3 to 5 mm.

[0017] In one possible design, the transition metal is copper, nickel, cobalt, manganese, cerium or lanthanum.

[0018] In one possible design, the catalyst is loaded onto the porous structure by impregnation.

[0019] In one possible design, the flame gun is ignited by methane.

[0020] It can be seen from the above scheme that the hot reflow burner for VOCs provided by the utility model can improve the combustion efficiency and stability of combustion by setting a stable combustion disk; by setting a porous structure loaded with a catalyst made of transition metals, the combustion temperature can be reduced, energy saving and consumption reduction can be achieved; by using a flame gun instead of an electric heating heat supply method, while ensuring the stable and efficient combustion of VOCs, energy consumption input can be reduced. Therefore, the above technical scheme can reduce energy consumption, improve combustion efficiency and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic structural diagram of a hot reflow burner for VOCs provided in an embodiment of the utility model.

[0023] Reference numerals:

[0024] 1-Stable combustion plate;

[0025] 2-porous structure;

[0026] 3- Combustion chamber;

[0027] 4- Flame gun;

[0028] 5- Preheating channel;

[0029] 6- Preprocessing unit. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.

[0031] In the related art, a burner is used to heat the waste gas to a temperature above the combustion temperature, and VOCs are completely converted into non-toxic carbon dioxide and water, which is suitable for organic waste gas with complex components and difficult to recover. Generally, combustible gas or electric heating is used for heating, and the combustion temperature is usually above 760°C, which will bring about the problem of high energy consumption and a large amount of heat being wasted. In order to reduce energy consumption and improve combustion efficiency and stability, the present invention has developed a VOCs high-efficiency heat reflux burner with a stable combustion disk and a porous structure.

[0032] See also Figure 1 The embodiment of the utility model provides a thermal reflow burner for VOCs, which comprises a combustion stabilizing plate 1, a porous structure 2 and a combustion chamber 3, wherein:

[0033] The combustion stabilizing plate 1 is used to diffuse the VOCs waste gas after it flows through;

[0034] The porous structure 2 is connected to the outlet of the combustion stabilizing disk 1, and a catalyst made of transition metal is loaded on the porous structure 2;

[0035] The combustion chamber 3 is connected to the outlet of the porous structure 2. A flame gun 4 is provided at the outlet of the combustion chamber 3. After the flame gun 4 ignites the VOCs waste gas, the flame generated can be backfired into the porous structure 2 (hence it is called a hot reflux burner) to preheat the VOCs waste gas.

[0036] In this embodiment, the combustion efficiency and stability of the combustion can be improved by providing a combustion stabilizing plate 1; the combustion temperature can be reduced by providing a porous structure 2 loaded with a catalyst made of transition metals, thereby saving energy and reducing consumption; and the heat supply method of the flame gun 4 is replaced by the electric heating method, while ensuring the stable and efficient combustion of VOCs, the energy consumption input is reduced. Therefore, the above technical solution can reduce energy consumption and improve combustion efficiency and stability.

[0037] In one embodiment of the present invention, the above-mentioned hot reflow burner further comprises:

[0038] The preheating channel 5 is connected to the inlet of the combustion stabilizing disk 1. The direction of the VOCs waste gas flowing in the preheating channel 5 is opposite to the direction of the VOCs waste gas flowing in the combustion stabilizing disk 1. The heat generated by the combustion on the surface of the porous structure 2 can be transferred to the preheating channel 5 to preheat the VOCs waste gas.

[0039] In this embodiment, by providing a preheating channel 5, the heat generated by the combustion on the surface of the porous structure 2 can be transferred to the preheating channel 5 to preheat the VOCs waste gas, which helps to better preheat the VOCs waste gas, so that tempering will be more likely to occur, reducing the tempering limit.

[0040] In one embodiment of the present invention, the above-mentioned hot reflow burner further comprises:

[0041] The pretreatment unit 6 is connected to the inlet of the preheating channel 5 and is used to filter dust in the VOCs exhaust gas.

[0042] In this embodiment, by providing the pre-treatment unit 6 , it is possible to prevent dust from being adsorbed in the porous structure 2 and clogging its pores.

[0043] In one embodiment of the present invention, the pretreatment unit 6 is a fiber filter or a dry-wet composite filter, which is not specifically limited herein.

[0044] In one embodiment of the present invention, the porous structure 2 is made of silicon carbide, zirconium oxide, aluminum oxide or cordierite, which is not specifically limited here. Such a configuration can ensure a larger thermal conductivity of the porous structure 2, so that more heat can be transferred from the downstream to the upstream.

[0045] In one embodiment of the present invention, the porous structure 2 is made by a hot alkali method.

[0046] Specifically, a mixed solution of deionized water and ethanol (for example, deionized water: ethanol = 5:1 to 15:1) is uniformly mixed with sodium hydroxide, and the mass ratio of the mixed solution to sodium hydroxide is 50:1 to 100:1; materials such as silicon carbide, zirconium oxide, aluminum oxide or cordierite are immersed in a mixed solution of sodium hydroxide and ethanol at 50 to 120° C., treated for 20 to 60 minutes and then dried; the dried carrier is calcined at 400 to 600° C. for 3 to 6 hours to obtain a porous structure 2.

[0047] In one embodiment of the present invention, the pore diameter of the porous structure 2 is 1.3-5 mm.

[0048] In one embodiment of the present invention, the transition metal is copper, nickel, cobalt, manganese, cerium or lanthanum, which is not specifically limited herein.

[0049] In one embodiment of the present invention, the catalyst is loaded onto the porous structure 2 by impregnation.

[0050] Specifically, firstly, a catalyst slurry is prepared: after heating a 1% to 5% pseudo-boehmite solution to 70 to 95°C, 1% to 5% nitric acid is added dropwise to keep the pH value of the solution at 3 to 5, and then after aging for 20 to 30 hours, a transition metal oxide powder (which can be one or two of copper, nickel, cobalt, manganese, cerium, and lanthanum oxides) is added, and the mass ratio of the transition metal oxide to nitric acid is 1:2 to 2:1; after stirring evenly, the mixture is ball milled at a speed of 50 to 200 r / min for 15 to 30 hours. Secondly, the porous medium material is impregnated: after the porous medium material is impregnated in the catalyst slurry for 20 to 60 minutes, it is dried in the shade at room temperature; then it is calcined at 450 to 550°C for 4 to 6 hours, and the heating rate is 1 to 5°C / min. In this way, the catalyst made of the transition metal can be loaded on the porous structure 2.

[0051] In one embodiment of the present invention, the flame gun 4 is ignited by methane. Of course, other combustible gases may also be used for ignition, which is not specifically limited here.

[0052] The following introduces the treatment process of VOCs waste gas.

[0053] After primary filtration by the pretreatment unit 6, the VOCs waste gas enters the preheating channel 5 for preheating, and then enters the combustion chamber 3 through the flame stabilizing plate 1 and the porous structure 2. The VOCs waste gas is ignited by a flame gun 4 at the outlet of the combustion chamber 3, and the flame will flash back to the porous structure 2 after a period of time. With the different concentrations of treated VOCs, different phenomena can be observed, such as flashback, combustion in the porous structure 2, and combustion on the surface of the porous structure 2. The porous structure 2 has a large thermal conductivity, which can transfer more heat from the downstream to the upstream, which helps the fresh gas to be better preheated, so flashback will be more likely to occur, reducing the flashback limit.

[0054] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the statement "comprise one..." do not exclude the existence of other identical factors in the process, method, article or equipment including the elements.

[0055] Finally, it should be noted that the above is only a preferred embodiment of the utility model, which is only used to illustrate the technical solution of the utility model, and is not used to limit the protection scope of the utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model are included in the protection scope of the utility model.

Claims

1. A hot reflow burner for VOCs, characterized in that: include: A combustion stabilizing plate (1) is used to diffuse the VOCs waste gas after it flows through; A porous structure (2) connected to the outlet of the combustion stabilizing disk (1) and loaded with a catalyst made of a transition metal; A combustion chamber (3) is connected to the outlet of the porous structure (2). A flame gun (4) is provided at the outlet of the combustion chamber (3). After the flame gun (4) ignites the VOCs waste gas, the flame generated can be backfired into the porous structure (2) to preheat the VOCs waste gas.

2. The hot reflow burner for VOCs according to claim 1, characterized in that: Also includes: A preheating channel (5) is connected to the inlet of the combustion stabilizing disk (1), and the direction in which the VOCs waste gas flows in the preheating channel (5) is opposite to the direction in which it flows in the combustion stabilizing disk (1). The heat generated by the combustion on the surface of the porous structure (2) can be transferred to the preheating channel (5) to preheat the VOCs waste gas.

3. The hot reflow burner for VOCs according to claim 2, characterized in that: Also includes: The pretreatment unit (6) is connected to the inlet of the preheating channel (5) and is used to filter dust in the VOCs waste gas.

4. The hot reflow burner for VOCs according to claim 3, characterized in that: The pretreatment unit (6) is a fiber filter or a dry-wet composite filter.

5. The hot reflow burner for VOCs according to claim 1, characterized in that: The porous structure (2) is made of silicon carbide, zirconium oxide, aluminum oxide or cordierite.

6. The hot reflow burner for VOCs according to claim 5, characterized in that: The porous structure (2) is produced by a hot alkali method.

7. The hot reflow burner for VOCs according to claim 5, characterized in that: The pore diameter of the porous structure (2) is 1.3 to 5 mm.

8. The hot reflow burner for VOCs according to claim 1, characterized in that: The transition metal is copper, nickel, cobalt, manganese, cerium or lanthanum.

9. The hot reflow burner for VOCs according to claim 8, characterized in that: The catalyst is loaded onto the porous structure (2) by an impregnation method.

10. The hot reflow burner for VOCs according to any one of claims 1 to 9, characterized in that: The flame gun (4) is ignited by methane.

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