Carbon-based ultralow-temperature SCR (Selective Catalytic Reduction) denitration device

Abstract

The utility model belongs to the field of flue gas treatment, and particularly relates to a carbon-based ultralow-temperature SCR (Selective Catalytic Reduction) denitration device which comprises a pretreatment tower, a discharge flue for exhausting gas is arranged at the upper part of the pretreatment tower, a gas inlet flue for feeding gas is arranged at the lower part of the pretreatment tower, and a through smoke inlet end seat is arranged on the side wall of the gas inlet flue; the heat exchange mechanism comprises a heat exchanger arranged in the inner cavity of the pretreatment tower; flue gas floating in the pretreatment tower is cooled by the heat exchange mechanism, then is subjected to primary reduction denitration through the spraying mechanism, and then is subjected to secondary treatment through the catalysis mechanism, the carbon-based catalysis fillers are arranged in a laminated mode, only the gas guide cylinder is arranged between the adjacent carbon-based catalysis fillers to serve as a flue gas channel, and an auger design of a spiral mechanism is adopted in the flue gas channel. The transmission path of the flue gas is increased, the flue gas and the carbon-based catalytic filler are fully reacted, the problem of insufficient catalytic reaction of the flue gas is solved, and the running time of a catalyst in the carbon-based catalytic filler is prolonged.

Description

Technical Field

[0001] The utility model relates to the field of flue gas treatment, in particular to a carbon-based ultra-low temperature SCR denitration device. Background Art

[0002] Nitrogen oxides (NOx) are usually produced during high-temperature combustion in industrial production. NO is oxidized into nitrogen dioxide (NO2) in the atmosphere, which is one of the main causes of chemical smog and acid rain. It can also damage the central nervous system and respiratory organs of animals, inhibit plant growth, and other hazards. It is particularly important and urgent to adopt effective denitrification measures to control nitrogen oxide pollution generated in the production process and protect the environment.

[0003] Selective catalytic reduction (SCR) denitrification technology is a mature, reliable and efficient denitrification technology. Its basic principle is to add a reducing agent (ammonia, ammonia water, urea) to the flue gas in the presence of a catalyst within a suitable temperature range. The reducing agent reacts with the NOx in the flue gas to generate harmless nitrogen and water, thereby achieving the purpose of denitrification. The catalyst is the core of the system. The selection and dosage of the catalyst directly affect the denitrification efficiency. At the same time, how to ensure that the catalyst can still maintain its activity under long-term use is a major problem. Utility Model Content

[0004] (I) Purpose of the utility model

[0005] In order to solve the technical problems existing in the background technology, the utility model proposes a carbon-based ultra-low temperature SCR denitrification device, which solves the influence of SO2 and H2O in the flue gas on the catalytic reduction reaction and effectively avoids the technical problem of catalyst deactivation in the traditional ultra-low temperature SCR denitrification device.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the utility model provides a carbon-based ultra-low temperature SCR denitrification device, comprising a pretreatment tower, wherein the upper part of the pretreatment tower is provided with a smoke exhaust duct for exhaust, and the lower part is provided with a smoke inlet duct for intake, and the side wall of the smoke inlet duct is installed with a through smoke inlet end seat;

[0008] The heat exchange mechanism comprises a heat exchanger arranged in the inner cavity of the pretreatment tower, and a liquid inlet end seat and a liquid return end seat penetrating the outer wall of the pretreatment tower are installed at both ends of the heat exchanger;

[0009] The spray mechanism comprises a liquid inlet pipe arranged above the heat exchanger, and a plurality of spray end seats facing the heat exchanger are installed at intervals on the liquid inlet pipe;

[0010] The catalytic mechanism comprises a first cartridge rack and a second cartridge rack which are stacked, wherein carbon-based catalytic fillers are clamped inside the first cartridge rack and adjacent carbon-based catalytic fillers are connected via an air guide tube, wherein an auger shaft is built in the air guide tube, and an auger with a spiral structure is sleeved on the outer wall of the auger shaft.

[0011] Preferably, the liquid inlet end seat and the liquid return end seat are connected to an external heat exchange chamber.

[0012] Preferably, the heat exchanger is a hollow "snake-shaped" structure.

[0013] Preferably, one end of the liquid inlet pipe passing through the outer wall of the pretreatment tower is connected to a valve, and the other end of the valve is connected to the reducing agent storage tank.

[0014] Preferably, the inner cavity of the pretreatment tower is provided with a uniform distribution plate with through holes, and the uniform distribution plate is arranged below the heat exchanger.

[0015] Preferably, at least one of the air guide tubes is provided between two of the carbon-based catalytic fillers, and the carbon-based catalytic filler is a breathable structure.

[0016] The above-mentioned technical scheme of the utility model has the following beneficial technical effects: the flue gas floating in the pretreatment tower is cooled by the heat exchange mechanism, and then initially reduced and denitrated by the spray mechanism, and then secondarily treated by the catalytic mechanism, wherein the carbon-based catalytic filler is arranged in a stacked manner, and only air guide tubes are arranged between adjacent carbon-based catalytic fillers as flue gas passages, and an auger design with a spiral mechanism is adopted inside, which increases the transmission path of the flue gas, enables the flue gas and the carbon-based catalytic filler to react fully, solves the problem of insufficient catalytic reaction of the flue gas, and increases the running time of the catalyst in the carbon-based catalytic filler. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional structural schematic diagram of the utility model;

[0018] Figure 2 It is a schematic diagram of the catalytic mechanism structure of the utility model;

[0019] Figure 3 It is a schematic diagram of the external structure of the utility model.

[0020] Reference numerals:

[0021] 11. Pretreatment tower; 12. Smoke inlet; 13. Smoke inlet terminal seat; 14. Smoke exhaust duct; 21. Liquid inlet terminal seat; 22. Heat exchanger; 23. Liquid return terminal seat; 31. Valve; 32. Liquid inlet pipe; 33. Spraying terminal seat; 41. First cylinder rack; 42. Second cylinder rack; 43. Carbon-based catalytic filler; 44. Air guide cylinder; 45. Auger shaft; 46. Auger; 5. Uniform distribution plate. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in combination with specific implementation methods and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0023] like Figure 1-3 As shown, a carbon-based ultra-low temperature SCR denitration device proposed in the utility model comprises a pretreatment tower 11, an exhaust duct 14 for exhaust is arranged at the upper part of the pretreatment tower 11, and an inlet duct 12 for air intake is arranged at the lower part, and a through-going inlet end seat 13 is installed on the side wall of the inlet duct 12;

[0024] The heat exchange mechanism includes a heat exchanger 22 disposed in the inner cavity of the pretreatment tower 11, and a liquid inlet end seat 21 and a liquid return end seat 23 penetrating the outer wall of the pretreatment tower 11 are installed at both ends of the heat exchanger 22;

[0025] The spray mechanism includes a liquid inlet pipe 32 disposed above the heat exchanger 22, and a plurality of spray end seats 33 facing the heat exchanger 22 are installed at intervals on the liquid inlet pipe 32;

[0026] The catalytic mechanism includes a first cartridge frame 41 and a second cartridge frame 42 which are stacked, and carbon-based catalytic fillers 43 are clamped inside the two cartridge frames. Adjacent carbon-based catalytic fillers 43 are connected via an air guide tube 44, and an auger shaft 45 is built in the air guide tube 44. The outer wall of the auger shaft 45 is sleeved with an auger 46 with a spiral structure.

[0027] It should be noted that the heat exchanger 22 is a hollow "snake-shaped" structure; its rotating coil increases the contact surface with the flue gas, which can cool the flue gas.

[0028] In this embodiment, the flue gas floating in the pretreatment tower 11 is cooled by the heat exchange mechanism, and then subjected to primary reduction and denitrification by the spray mechanism, and subsequently subjected to secondary treatment by the catalytic mechanism, wherein the carbon-based catalytic fillers 43 are arranged in a stacked manner, and only air guide tubes 44 are arranged between adjacent carbon-based catalytic fillers 43 as flue gas passages, and an auger 46 with a spiral mechanism is adopted inside, which increases the transmission path of the flue gas, enables the flue gas and the carbon-based catalytic fillers 43 to fully react, solves the problem of insufficient catalytic reaction of the flue gas, and increases the operating time of the catalyst in the carbon-based catalytic fillers 43.

[0029] Among them, at least one air guide tube 44 is provided between two carbon-based catalytic fillers 43 , and seven are provided in the present application, and the carbon-based catalytic filler 43 is a breathable structure.

[0030] It should be added that the inner cavity of the pretreatment tower 11 is provided with a uniform distribution plate 5 with through holes, and the uniform distribution plate 5 is arranged below the heat exchanger 22. When the flue gas floating along the flue inlet 12 passes through the through holes of the uniform distribution plate 5, the floating flue gas is evenly distributed, and at the same time, excessive floating of the flue gas can be prevented.

[0031] In order to keep the flue gas in an ultra-low temperature environment during the circulation of the pretreatment tower, the liquid inlet end seat 21 and the liquid return end seat 23 are further connected to the external heat exchange chamber, and the cooling water in the heat exchange chamber is sucked into the liquid inlet end seat 21, and contacts and exchanges heat with the flue gas during the circulation in the heat exchanger 22, so as to complete the cooling of the flue gas. At the same time, the waste heat is recovered to the heat exchange chamber through the liquid return end seat 23 along with the circulating water.

[0032] In order to facilitate the spraying of the reducing agent, further, a liquid inlet pipe 32 passes through the outer wall of the pretreatment tower 11 and is connected to a valve 31 at one end, and the other end of the valve 31 is connected to the reducing agent storage tank; the reducing agent storage tank is transported to the liquid inlet pipe 32 through the valve 31, and the reducing agent is sprayed downward through each spraying end seat 33. Within a suitable temperature range, the reducing agent (ammonia, ammonia water, urea) is added to the flue gas, and the reducing agent reacts with the NOx in the flue gas to generate harmless nitrogen and water, thereby achieving the purpose of denitrification.

[0033] The working principle and use process of the utility model are as follows: the flue gas is pretreated by a heat exchange mechanism and a spray mechanism, and the catalytic mechanism is used to effectively remove soluble alkali metal salts such as sodium and potassium in the flue gas, and at the same time SO2 is removed to a lower concentration, thereby increasing the operating time of the catalyst in the carbon-based catalytic filler 43. The catalyst is a carbon-based catalyst, that is, a catalyst prepared by using a carbonaceous material as a carrier to load a metal oxide. Since the carbon base has the characteristics of large surface area and chemical stability, a carbon-based catalyst can be prepared by using various carbon-based materials as carriers to load metal oxides. The types and quantities of active components of the loaded metal oxides are different and will also have an important influence on its catalytic activity. Studies have shown that WO3 has good resistance to SO2. Through experiments, a carbon-based catalyst that uses a carbon-based carrier to load WO3 and adds some rare earth can prevent the low concentration of SO2 in the flue gas after the pretreatment system from poisoning the catalyst at low and ultra-low temperatures, and has good low-temperature selective catalytic reduction activity.

[0034] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the claims attached to the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.

Claims

1. A carbon-based ultra-low temperature SCR denitrification device, characterized in that: It comprises a pretreatment tower (11), wherein the upper part of the pretreatment tower (11) is provided with a smoke exhaust duct (14) for exhaust, and the lower part is provided with a smoke inlet duct (12) for air intake, and the side wall of the smoke inlet duct (12) is installed with a through smoke inlet end seat (13); The heat exchange mechanism comprises a heat exchanger (22) arranged in the inner cavity of the pretreatment tower (11), and a liquid inlet end seat (21) and a liquid return end seat (23) penetrating the outer wall of the pretreatment tower (11) are installed at both ends of the heat exchanger (22); The spray mechanism comprises a liquid inlet pipe (32) arranged above the heat exchanger (22), and a plurality of spray end seats (33) facing the heat exchanger (22) are installed at intervals on the liquid inlet pipe (32); The catalytic mechanism comprises a first cartridge frame (41) and a second cartridge frame (42) which are stacked, wherein carbon-based catalytic fillers (43) are clamped inside the first cartridge frame and adjacent carbon-based catalytic fillers (43) are connected via an air guide tube (44), wherein an auger shaft (45) is built in the air guide tube (44), and an auger (46) with a spiral structure is sleeved on the outer wall of the auger shaft (45).

2. A carbon-based ultra-low temperature SCR denitration device according to claim 1, characterized in that: The liquid inlet end seat (21) and the liquid return end seat (23) are connected to an external heat exchange chamber.

3. A carbon-based ultra-low temperature SCR denitration device according to claim 1, characterized in that: The heat exchanger (22) is a hollow "snake-shaped" structure.

4. A carbon-based ultra-low temperature SCR denitration device according to claim 1, characterized in that: One end of the liquid inlet pipe (32) passing through the outer wall of the pretreatment tower (11) is connected to a valve (31), and the other end of the valve (31) is connected to the reducing agent storage tank.

5. A carbon-based ultra-low temperature SCR denitration device according to claim 1, characterized in that: The inner cavity of the pretreatment tower (11) is provided with a uniform distribution plate (5) with through holes, and the uniform distribution plate (5) is arranged below the heat exchanger (22).

6. A carbon-based ultra-low temperature SCR denitration device according to claim 1, characterized in that: At least one of the air guide cylinders (44) is arranged between two of the carbon-based catalytic fillers (43), and the carbon-based catalytic fillers (43) are of an air-permeable structure.

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