Treatment device for flue gas generated in brick sintering and making process of polluted soil tunnel kiln

Abstract

The utility model relates to the technical field of waste gas treatment, and provides a treatment device for flue gas generated in a polluted soil tunnel kiln sintering brick making process. The treatment device comprises a high-temperature electric dust remover and an SCR (Selective Catalytic Reduction) denitration reactor which are sequentially connected, the high-temperature electric dust remover is connected with the SCR denitration reactor through a flue gas pipeline, a filter layer is arranged in the flue gas pipeline, and the filter layer comprises a filter material layer and an adsorbent layer. By means of the high-temperature electric precipitator and the filtering layer, the high-temperature and high-dust flue gas can be thoroughly dedusted, dust and gaseous pollutants in the flue gas can be separated and removed in the high-temperature section, and the purification pressure of a follow-up SCR denitration reactor is relieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste gas treatment, and relates to a device for treating flue gas produced in a contaminated soil tunnel kiln sintering brick-making process. Background Art

[0002] In industrial and agricultural production and life, a large number of organic pollutants and heavy metal pollutants are discharged into the environment directly or indirectly, and a large part of the pollutants are enriched or remain in the soil, endangering the ecological environment and human health. In a certain way, organic-heavy metal contaminated soil is mixed into the raw materials for sintering bricks and sintered at high temperature. It can not only efficiently decompose and remove various toxic and harmful substances in the contaminated soil through high-temperature combustion, but also use the contaminated soil as raw material for tunnel kiln brick making, realizing the resource utilization of contaminated soil.

[0003] However, due to the complexity and diversity of pollutants contained in the contaminated soil, the flue gas (including dust, NO X The purification and emission compliance of pollutants such as sulfur oxides and dioxins (such as sulfur oxides and dioxins) are issues that need attention. The suitable resynthesis temperature range of dioxin precursors decomposed by high temperature in contaminated soil outside the tunnel kiln is 200-500℃. After being catalyzed by metal compound dust such as ferric chloride and cupric chloride, they will quickly recombine to form dioxins. If the solid and gaseous pollutants in the exhaust gas are not properly handled, they will pollute the environment.

[0004] As contaminated soil is increasingly treated by tunnel kiln sintering brick-making resource utilization technology, the types and forms of pollutants emitted during the firing process are more complex and difficult to treat. However, the existing waste gas treatment devices are ineffective in treating the flue gas produced by the sintering of contaminated soil or are costly, making them difficult to use directly. Utility Model Content

[0005] The utility model provides a device for treating flue gas produced in a contaminated soil tunnel kiln sintering brick-making process, so as to solve the problems in existing related flue gas treatment systems or devices, such as poor treatment effect on solid-gas mixed flue gas produced in the sintering process of contaminated soil, difficulty in meeting emission standard requirements, and easy to cause environmental pollution.

[0006] The utility model discloses a device for treating flue gas produced in the process of sintering bricks in a contaminated soil tunnel kiln, comprising a high-temperature electrostatic precipitator and an SCR denitrification reactor connected in sequence; the high-temperature electrostatic precipitator and the SCR denitrification reactor are connected via a flue gas duct, a filter layer is provided in the flue gas duct, and the filter layer comprises a filter material layer and an adsorbent layer.

[0007] Optionally, the filter layer has three layers from top to bottom, the middle layer is an adsorbent layer, and the upper and lower layers are filter material layers.

[0008] Optionally, in the upper and lower filter material layers, smoke flows in from the upper filter material layer and flows out from the lower filter material layer after filtration; the filter material pores of the upper filter material layer are larger than the filter material pores of the lower filter material layer.

[0009] Optionally, the filter material layer is a sheet of metal fiber felt, and the adsorbent layer is formed by filling with nano-active silicon material and is clamped and fixed by upper and lower layers of metal fiber felt.

[0010] Optionally, smoke flows in from the upper filter material layer and flows out from the lower filter material layer after being filtered; the pore size of the upper metal fiber felt is larger than the pore size of the lower metal fiber felt.

[0011] Optionally, the cross-section of the flue gas duct is circular, the filter layer is in the shape of a flat cylinder or a round cake, the outer shell of the filter layer is a filter material layer composed of metal fiber felt, and the interior of the filter layer is an adsorbent layer composed of nano-active silicon material.

[0012] Optionally, the filter layer is detachably connected to the inner wall of the smoke duct, and a filter layer inspection port is provided on the wall of the smoke duct where the filter layer is located.

[0013] Optionally, the inlet of the high-temperature electrostatic precipitator is connected to the tunnel kiln smoke exhaust pipe.

[0014] Optionally, the outlet of the SCR denitration reactor is connected to a fan.

[0015] The flue gas treatment device of the utility model first uses a high-temperature electrostatic precipitator to pre-de-dust the high-temperature and high-dust flue gas, relieving the dust removal and purification pressure of the subsequent device, and then uses the filter layer set in the flue to fully filter and remove the dust and other solid particles in the flue gas. The dust removal device of the high-temperature electrostatic precipitator and the filter layer can completely remove the high-temperature and high-dust flue gas, complete the separation and removal of dust and gaseous pollutants in the flue gas in the high-temperature section, and relieve the purification pressure of the subsequent SCR denitration reactor.

[0016] Furthermore, by setting up a sandwich structure of the filter layer and selecting nano-active silicon material as an adsorbent, combined with a metal fiber felt filter layer to form a metal fiber felt sandwiched with a nano-active silicon layer, it is possible to filter and prevent dioxin precursors from contacting dust in a suitable low-temperature range and re-catalyzing and combining to generate dioxins, and further alleviate the purification pressure of the subsequent SCR denitrification reactor, reduce the amount of catalyst used, and improve the dust removal, denitrification, desulfurization and dioxin removal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the device structure of the utility model;

[0018] Figure 2 It is a schematic structural diagram of the filter layer of an embodiment of the utility model.

[0019] In the figure, 1-high temperature electrostatic precipitator; 2-filter layer; 3-SCR denitrification reactor; 4-tunnel kiln exhaust pipe; 5-fan; 6-filter layer inspection port; 7-nano-active silicon material; 8-metal fiber felt; 9-flue gas duct. DETAILED DESCRIPTION

[0020] The technical solution of the utility model is described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0021] The flue gas treatment device of the utility model includes a high-temperature electrostatic precipitator and an SCR denitration reactor connected in sequence; the high-temperature electrostatic precipitator and the SCR denitration reactor are connected through a flue gas duct, and a filter layer is provided in the flue gas duct, and the filter layer includes an adsorbent layer and a filter material layer, so that the flue gas from the outlet of the high-temperature electrostatic precipitator enters the SCR denitration reactor after filtering and adsorption. The high-temperature electrostatic precipitator is connected to an external smoke exhaust duct, and the smoke discharged from the outside enters the high-temperature electrostatic precipitator, is discharged after pre-dust removal by the high-temperature electrostatic precipitator, and is further filtered and adsorbed in the filter layer of the flue gas duct, and then enters the SCR denitration reactor for subsequent denitration purification, and is discharged after purification.

[0022] The filter layer can be provided with multiple layers, including a filter material layer and an adsorbent layer, the filter material plays a role in filtering dust and other particulate matter, and the adsorbent is provided in the adsorbent layer to adsorb pollutants. The specific structure of the multi-layer filter layer can be provided with a structure of an outer surface filter material layer and an inner adsorbent layer, or a laminated sandwich structure, for example, three layers are provided in total according to the flue gas flow direction, the middle layer is an adsorbent layer, and the upper and lower layers are filter material layers.

[0023] More specifically, the filter material layer can be composed of sheet-like metal fiber felt, and the adsorbent layer is filled with nano-active silicon material and clamped and fixed by upper and lower layers of metal fiber felt. Metal fiber felt has the advantages of high temperature resistance, stable properties, good filtering effect, and recyclability. The nano-active silicon material is a white solid powder amorphous silicate, mainly containing elements such as silicon, calcium, iron, manganese, and aluminum. The nano-active silicon material has developed pores, strong adsorption performance and high temperature resistance, and still has a good removal effect on dioxins under high temperature environment. The prepared metal fiber felt sandwiched with nano-active silicon filter layer is suitable for use in high temperature environment, and can fully filter and remove solid particles such as dust in the flue gas, adsorb and remove dioxins in the flue gas, and can also remove some sulfur oxides.

[0024] Example 1

[0025] When treating the contaminated soil, it is treated and utilized as a resource by sintering bricks in a tunnel kiln, and the flue gas produced during the sintering process needs to be treated. The flue gas treatment device of this embodiment can solve the problem that the solid-gas mixed flue gas containing dioxin pollution generated during the sintering brick making process of organic-heavy metal contaminated soil with complex pollution in a tunnel kiln is difficult to treat and easily causes environmental pollution.

[0026] like Figure 1 As shown, the treatment device for flue gas produced by sintering contaminated soil in this embodiment is a pollution prevention and control device for flue gas produced by sintering contaminated soil in a tunnel kiln, which is composed of a high-temperature electrostatic precipitator 1 connected in series with an SCR denitration reactor 3 through a flue gas duct 9 provided with a filter layer 2. Among them, the inlet of the high-temperature electrostatic precipitator 1 is connected to the tunnel kiln exhaust pipe 4, and the smoke inlet (smoke inlet) of the SCR denitration reactor 3 is connected to the smoke outlet (smoke outlet) of the high-temperature electrostatic precipitator 1 through the flue gas duct 9. More specifically, the smoke outlet of the high-temperature electrostatic precipitator 1 is located at the top, and the smoke inlet of the SCR denitration reactor is located at the bottom of the reactor. The smoke discharged from the high-temperature electrostatic precipitator 1 enters the SCR denitration reactor after being filtered and adsorbed by the filter layer 2 from top to bottom in the smoke duct 9, and the outlet of the SCR denitration reactor 3 is connected to the fan 5 through the smoke exhaust duct. The filter layer 2 of this embodiment is a metal fiber felt sandwiched with nano-active silicon filter layer, which is arranged in the flue gas duct 9 between the high-temperature electrostatic precipitator 1 and the SCR denitration reactor 3, and the cross-section of the flue gas duct 9 is circular.

[0027] like Figure 2 As shown, the metal fiber felt sandwiched with nano-active silicon filter layer of this embodiment is a double-layer metal fiber felt filter layer structure filled with nano-active silicon material 7, and the outer shell is a metal fiber felt 8 in the shape of a round cake / flat cylinder, and the interior is filled with nano-active silicon material 7. The metal fiber felt 8 is a filter layer, and the nano-active silicon material 7 constitutes an adsorbent layer. In the upper and lower double layers of metal fiber felt, the pore size of the second layer of metal fiber felt is smaller than that of the first layer, so that the filter layer has a better smoke dust filtering effect. The filter layer 2 is detachably connected to the inner wall of the flue gas duct 9, and a filter layer inspection port 6 is provided on the duct wall where the filter layer 2 is installed to facilitate the recovery and replacement of the filter layer.

[0028] The high-temperature and high-dust flue gas generated by organic-heavy metal and other composite polluted soils during the sintering process first enters the high-temperature electrostatic precipitator 1 through the tunnel kiln exhaust pipe 4, and the high-temperature electrostatic precipitator 1 is used to pre-de-dust the flue gas, and then the flue gas with most of the dust removed enters the flue gas pipeline 9 connected to the SCR denitration reactor 3, and the metal fiber felt in the pipeline is used to filter the high-temperature flue gas with the nano-active silicon filter layer 2 to achieve the purpose of secondary dust removal and adsorption of dioxins and some sulfur oxides. The high-temperature and high-dust flue gas is thoroughly de-dusted by two dust removal devices, and the dust and gaseous pollutants in the flue gas are separated and removed in the high-temperature section, preventing dioxin precursors from contacting with dust in a suitable low-temperature range, re-catalyzing and combining to generate dioxins, and relieving the purification pressure of the subsequent SCR denitration reactor 3, reducing the amount of catalyst, and improving the dust removal, denitration, desulfurization and dioxin removal efficiency. Then, the flue gas after dust removal and filtration adsorption enters the SCR denitration reactor 3 for subsequent denitration purification treatment. In a high temperature and low dust environment, the amount of catalyst can be reduced and a catalyst with a small pore size can be used. At the same time, the temperature of the flue gas provides the heat required for the evaporation of the repair agent of the SCR denitration reactor 3, which can improve the repair efficiency and energy utilization efficiency.

[0029] The present invention is described in detail above in combination with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, the technical solution and implementation methods of the present invention can be subjected to various equivalent substitutions, modifications or improvements, all of which fall within the scope of the present invention.

Claims

1. A device for treating flue gas produced during the sintering and brick-making process of a contaminated soil tunnel kiln, characterized in that: It comprises a high-temperature electrostatic precipitator and an SCR denitration reactor which are connected in sequence; the high-temperature electrostatic precipitator and the SCR denitration reactor are connected via a flue gas duct, a filter layer is arranged in the flue gas duct, and the filter layer comprises a filter material layer and an adsorbent layer.

2. The processing device according to claim 1, characterized in that The filter layer has three layers from top to bottom, the middle layer is an adsorbent layer, and the upper and lower layers are filter material layers.

3. The processing device according to claim 2, characterized in that In the upper and lower filter material layers, smoke flows in from the upper filter material layer and flows out from the lower filter material layer after being filtered; the filter material pores of the upper filter material layer are larger than the filter material pores of the lower filter material layer.

4. The processing device according to claim 2, characterized in that The filter material layer is a sheet of metal fiber felt, and the adsorbent layer is filled with nano-active silicon material and is clamped and fixed by upper and lower layers of metal fiber felt.

5. The processing device according to claim 4, characterized in that The smoke flows in from the upper filter material layer and flows out from the lower filter material layer after being filtered; the pore size of the upper metal fiber felt is larger than the pore size of the lower metal fiber felt.

6. The processing device according to claim 1, characterized in that The cross section of the flue gas duct is circular, the filter layer is in the shape of a flat cylinder or a round cake, the outer shell of the filter layer is a filter material layer composed of metal fiber felt, and the interior of the filter layer is an adsorbent layer composed of nano-active silicon material.

7. The processing device according to claim 1, characterized in that The filter layer is detachably connected to the inner wall of the smoke pipe, and a filter layer inspection port is arranged on the pipe wall of the smoke pipe where the filter layer is located.

8. The processing device according to any one of claims 1 to 7, characterized in that: The inlet of the high-temperature electric precipitator is connected to the tunnel kiln smoke exhaust pipe.

9. The processing device according to claim 1, characterized in that The outlet of the SCR denitration reactor is connected to a fan.

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