Medium and low temperature desulfurization and denitrification system

Abstract

The utility model relates to the technical field of flue gas denitration, in particular to a medium and low temperature desulfurization and denitration system. The medium and low temperature desulfurization and denitrification system comprises a desulfurization unit, a dust removal unit, an ozone oxidation unit, a reducing agent injection unit, a denitrification unit and a flue gas control unit which are connected in sequence; wherein the ozone oxidation unit is used for carrying out oxidation reaction on part of nitric oxide in the flue gas to generate nitrogen dioxide. The medium and low temperature desulfurization and denitrification system disclosed by the utility model is high in denitrification efficiency, low in energy consumption and strong in adaptability, realizes high-efficiency and low-energy-consumption denitrification under the condition that the medium temperature and the low temperature of flue gas can be switched by combining an ozone oxidation technology and a rapid SCR (Selective Catalytic Reduction) reaction, and can be suitable for working conditions with a wide flue gas temperature range.

Description

Technical Field

[0001] The utility model relates to the technical field of flue gas denitration, in particular to a medium- and low-temperature desulfurization and denitration system. Background Art

[0002] At present, emission standards in various regions are becoming increasingly stringent, and ultra-low emission requirements are an inevitable trend in the development of the ecological environment. Among them, the selective catalytic reduction denitrification technology (NH3-SCR) using ammonia or urea as a reducing agent is currently the most mature and efficient NO x Removal technology. After years of research and industrial practice, a denitration catalyst system with vanadium and titanium as the main catalyst has been formed. The operating temperature is usually between 280-420℃, and the denitration efficiency can reach more than 85%.

[0003] The application of medium-low temperature and wide temperature range SCR systems in industrial furnaces is a technical problem that needs to be solved urgently.

[0004] Conventional SCR denitrification systems cannot adapt well to the flue gas temperature range of 150-220℃, which in turn affects the denitrification efficiency of the catalyst. Although fast SCR technology can achieve efficient denitrification at medium and low temperatures, there is still room for improvement in the adaptability of the device system. Utility Model Content

[0005] In order to solve the problem that the existing medium and low temperature desulfurization and denitrification systems cannot adapt to the ultra-low emission requirements of medium and low temperature flue gas of 150-220°C, the utility model proposes a medium and low temperature desulfurization and denitrification system.

[0006] The utility model provides a medium-low temperature desulfurization and denitrification system, comprising a desulfurization unit, a dust removal unit, an ozone oxidation unit, a reducing agent injection unit, a denitrification unit and a flue gas control unit connected in sequence; wherein the ozone oxidation unit is used for oxidizing part of the nitrogen monoxide in the flue gas to generate nitrogen dioxide.

[0007] In the utility model, the above desulfurization and denitrification system is used to carry out a rapid SCR reaction, and desulfurization and denitrification can be successfully achieved at 150-220°C.

[0008] According to a medium-low temperature desulfurization and denitrification system provided by the utility model, the ozone oxidation unit includes an ozone generating device, a gas source device and an ozone releasing device.

[0009] According to a medium-low temperature desulfurization and denitrification system provided by the utility model, the ozone generating device includes an ozone generator, and the ozone generator includes electrodes and a reaction chamber; the electrodes are used to electrolyze water or electrocute air to generate ozone, and the reaction chamber is used to react and generate ozone.

[0010] According to a medium- and low-temperature desulfurization and denitrification system provided by the utility model, the ozone generating device also includes a control device, which includes a sensor and a control panel; the control device is used to monitor and adjust the parameters of ozone generation; and / or the ozone generating device also includes a cooling device, which includes a fan, a heat sink or a coolant circulation device; and / or the ozone generating device also includes a safety device, which includes a leak detector and an emergency stop button.

[0011] According to a medium-low temperature desulfurization and denitrification system provided by the utility model, the gas source device is used to provide high-purity oxygen or air as an oxygen source for generating ozone.

[0012] According to a medium-low temperature desulfurization and denitrification system provided by the utility model, the ozone release device includes a delivery pipeline or a nozzle; the ozone release device is used to release the generated ozone to a target treatment area.

[0013] According to a medium-low temperature desulfurization and denitration system provided by the utility model, the denitration unit includes a denitration reactor and is provided with a catalyst layer; the denitration reactor is used for rapid SCR reaction, and the catalyst layer is used for placing a catalyst.

[0014] According to a medium-low temperature desulfurization and denitrification system provided by the utility model, the denitrification reactor is also provided with an ozone injection port for injecting ozone into the reactor.

[0015] According to a medium-low temperature desulfurization and denitrification system provided by the utility model, the reductant injection unit includes a reductant storage tank, a delivery pipeline and a nozzle; the reductant injection unit is used to uniformly inject the reductant into the denitrification unit to perform a rapid SCR reaction with NOx.

[0016] According to a medium- and low-temperature desulfurization and denitrification system provided by the utility model, the desulfurization unit includes a dry desulfurization tower, a nozzle, a feeder and a metering system; the desulfurization unit is used to pump the desulfurization powder evenly into the dry desulfurization tower to react with the sulfide in the flue gas; and / or, the dust removal unit includes a pulse bag dust collector, and the pulse bag dust collector includes a filter element, a bag cage, a pulse cleaning device, an air-locking unloader and a control device; the dust removal unit is used to filter and collect dust in the flue gas so that clean flue gas is discharged from the exhaust duct; and / or, the flue gas control unit is used to automatically adjust and control parameters, and the parameters include the reducing agent injection amount, the ozone injection amount, the reaction temperature, and the flue gas flow rate.

[0017] The utility model provides a medium and low temperature desulfurization and denitrification system, which realizes efficient denitrification under medium and low temperature conditions by optimizing the denitrification machine structure and combining the rapid SCR technology and the ozone oxidation technology. Among them, the ozone oxidation reaction promotes the rapid SCR reaction in the reactor, forming a synergistic effect and improving the medium and low temperature denitrification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 The utility model provides a flow chart of a medium and low temperature desulfurization and denitrification system.

[0020] Figure numerals: 1 is a desulfurization unit, 2 is a dust removal unit, 3 is an ozone oxidation unit, 4 is a reducing agent injection unit, 5 is a denitrification unit, and 6 is a flue gas control unit. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be described clearly and completely in conjunction with the drawings in the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] At present, the flue gas purification technology of ultra-low temperature denitrification below 180°C is in a state of development of "application and maturity". The medium and low temperature SCR denitrification system has the advantages of small impact on kiln conditions and low cost, and there is no major modification to the process equipment with existing traditional SCR layout. At present, commercial vanadium-based catalysts are the most widely used, the production process is the most mature, and it is easiest to industrialize quickly. However, it is impossible to achieve efficient denitrification at ultra-low temperatures by using only high-activity vanadium-based catalysts. In the rapid SCR reaction, NO and NO2 participate in the reaction at the same time, which can greatly promote the denitrification reaction activity of the catalyst at low temperatures. Combining the two can achieve efficient denitrification under ultra-low temperature flue gas conditions. Therefore, the medium and low temperature controllable desulfurization and denitrification device system of flue gas is based on the rapid SCR reaction, which is more conducive to broadening the application scope of denitrification technology, thereby meeting the increasingly severe environmental emission pressure and indicators.

[0023] Based on this, the utility model has the following technical solutions:

[0024] Combine the following Figure 1 Describe the medium and low temperature desulfurization and denitrification system of the utility model. Figure 1 The utility model provides a flow chart of a medium and low temperature desulfurization and denitrification system.

[0025] The utility model provides a medium-low temperature desulfurization and denitrification system, comprising a desulfurization unit 1, a dust removal unit 2, an ozone oxidation unit 3, a reducing agent injection unit 4, a denitrification unit 5 and a flue gas control unit 6 which are connected in sequence; wherein the ozone oxidation unit 3 is used to oxidize part of the nitrogen monoxide in the flue gas to generate nitrogen dioxide.

[0026] According to a preferred embodiment provided by the utility model, the ozone oxidation unit 3 includes an ozone generating device, a gas source device and an ozone releasing device.

[0027] According to a preferred embodiment provided by the utility model, the ozone generating device includes an ozone generator, and the ozone generator includes electrodes and a reaction chamber; the electrodes are used to electrolyze water or electrocute air to generate ozone, and the reaction chamber is used to react and generate ozone.

[0028] In the utility model, the electrode is generally made of metal or ceramic material, and ozone is generated by electrolyzing water or electrocuting air.

[0029] According to a preferred embodiment provided by the utility model, the ozone generating device further comprises a control device, and the control device comprises a sensor and a control panel; the control device is used to monitor and adjust the parameters of ozone generation.

[0030] In the present invention, since ozone generation is usually accompanied by heat released by the reaction, the ozone generator usually requires cooling equipment to maintain a suitable temperature. According to a preferred embodiment provided by the present invention, the ozone generating device also includes a cooling device, which includes a fan, a heat sink or a coolant circulation device.

[0031] In the present invention, since ozone is an oxidizing gas that may be harmful to the human body, the ozone generator needs to be equipped with safety equipment to ensure safe operation. According to a preferred embodiment provided by the present invention, the ozone generating device also includes safety equipment, which includes a leak detector and an emergency stop button.

[0032] According to a preferred embodiment provided by the utility model, the gas source device is used to provide high-purity oxygen or air as an oxygen source for generating ozone.

[0033] According to a preferred embodiment provided by the utility model, the ozone releasing device includes a delivery pipe or a nozzle; the ozone releasing device is used to release the generated ozone to a target treatment area.

[0034] According to a preferred embodiment provided by the utility model, the denitration unit 5 includes a denitration reactor and is provided with a catalyst layer; the denitration reactor is used for rapid SCR reaction, and the catalyst layer is used for placing a catalyst.

[0035] According to a preferred embodiment provided by the utility model, the denitration reactor is also provided with an ozone injection port for injecting ozone into the reactor.

[0036] According to a preferred embodiment provided by the utility model, the reducing agent injection unit includes a reducing agent storage tank, a delivery pipeline and a nozzle; the reducing agent injection unit is used to uniformly inject the reducing agent into the denitration unit 5 to perform a rapid SCR reaction with NOx.

[0037] According to a preferred embodiment provided by the utility model, the desulfurization unit 1 includes a dry desulfurization tower, a nozzle, a feeder and a metering system; the desulfurization unit 1 is used to pump the desulfurization powder evenly into the dry desulfurization tower to react with the sulfide in the flue gas; and / or, the dust removal unit 2 includes a pulse bag dust collector, the pulse bag dust collector includes a filter element, a bag cage, a pulse cleaning device, a wind lock discharger and a control device; the dust removal unit 2 is used to filter and collect dust in the flue gas, so that the clean flue gas is discharged from the exhaust duct. And / or, the flue gas control unit 6 is used to automatically adjust and control parameters, and the parameters include the amount of reducing agent injection, the amount of ozone injection, the reaction temperature, and the flue gas flow rate.

[0038] In the utility model, the flue gas control unit 6 can adopt the DCS or PLC technology in the prior art to realize automatic adjustment and control of parameters such as the reducing agent injection amount, ozone injection amount, reaction temperature, flue gas flow rate, etc., to ensure that the entire denitrification process is efficient and controllable under low temperature conditions.

[0039] The medium and low temperature desulfurization and denitrification system described in the utility model has high denitrification efficiency, low energy consumption and strong adaptability. It combines ozone oxidation technology and fast SCR reaction to achieve high-efficiency and low-energy denitrification under the conditions of medium and low temperature switchable flue gas, and can adapt to working conditions with a wide range of flue gas temperatures.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the utility model.

Claims

1. A medium and low temperature desulfurization and denitrification system, characterized in that: It comprises a desulfurization unit, a dust removal unit, an ozone oxidation unit, a reducing agent injection unit, a denitrification unit and a flue gas control unit which are connected in sequence; wherein the ozone oxidation unit is used to oxidize part of the nitrogen monoxide in the flue gas to generate nitrogen dioxide.

2. The medium and low temperature desulfurization and denitrification system according to claim 1, characterized in that: The ozone oxidation unit comprises an ozone generating device, a gas source device and an ozone releasing device.

3. The medium and low temperature desulfurization and denitrification system according to claim 2 is characterized in that: The ozone generating device comprises an ozone generator, and the ozone generator comprises electrodes and a reaction chamber; the electrodes are used for electrolyzing water or electrocuting air to generate ozone, and the reaction chamber is used for reacting to generate ozone.

4. The medium and low temperature desulfurization and denitrification system according to claim 2, characterized in that: The ozone generating device further includes a control device, which includes a sensor and a control panel; the control device is used to monitor and adjust the parameters of ozone generation; and / or, the ozone generating device further includes a cooling device, which includes a fan, a heat sink or a coolant circulation device; and / or, the ozone generating device further includes a safety device, which includes a leak detector and an emergency stop button.

5. The medium and low temperature desulfurization and denitrification system according to claim 2, characterized in that: The gas source device is used to provide high-purity oxygen or air as an oxygen source for generating ozone.

6. The medium and low temperature desulfurization and denitrification system according to claim 2, characterized in that: The ozone releasing device comprises a delivery pipe or a nozzle; the ozone releasing device is used to release the generated ozone to a target treatment area.

7. The medium and low temperature desulfurization and denitrification system according to claim 1, characterized in that: The denitration unit comprises a denitration reactor and is provided with a catalyst layer; the denitration reactor is used for rapid SCR reaction, and the catalyst layer is used for placing a catalyst.

8. The medium and low temperature desulfurization and denitrification system according to claim 7, characterized in that: The denitration reactor is also provided with an ozone injection port for injecting ozone into the reactor.

9. The medium and low temperature desulfurization and denitrification system according to claim 1, characterized in that: The reducing agent injection unit comprises a reducing agent storage tank, a delivery pipeline and a nozzle; the reducing agent injection unit is used to uniformly inject the reducing agent into the denitration unit to perform a rapid SCR reaction with NOx.

10. The medium and low temperature desulfurization and denitrification system according to claim 1, characterized in that: The desulfurization unit includes a dry desulfurization tower, a nozzle, a feeder and a metering system; the desulfurization unit is used to pump the desulfurization powder evenly into the dry desulfurization tower to react with the sulfide in the flue gas; and / or, the dust removal unit includes a pulse bag dust collector, and the pulse bag dust collector includes a filter element, a bag cage, a pulse cleaning device, an air-locking discharger and a control device; the dust removal unit is used to filter and collect dust in the flue gas so that the clean flue gas is discharged from the exhaust duct; and / or, the flue gas control unit is used to automatically adjust and control parameters, and the parameters include the reducing agent injection amount, the ozone injection amount, the reaction temperature, and the flue gas flow rate.

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