Coking HPF desulfurization waste liquid incineration acid-making flue gas treatment system

Abstract

The utility model provides a coking HPF desulfurization waste liquid incineration acid-making flue gas treatment system. The coking HPF desulfurization waste liquid incineration acid-making flue gas treatment system comprises an incinerator, a first-stage denitration unit, a high-temperature dust purification mechanism and a second-stage denitration unit, an air outlet of the incinerator is connected with an air inlet of the first-stage denitration unit, an air outlet of the first-stage denitration unit is connected with an air inlet of the high-temperature dust purification mechanism, an air outlet of the high-temperature dust purification mechanism is connected with an air inlet of the second-stage denitration unit, and an air outlet of the second-stage denitration unit is externally connected with a flue gas acid making section. According to the utility model, the primary denitration unit and the secondary denitration unit are designed between the incinerator and the flue gas acid-making section to carry out two-stage deep denitration treatment on the desulfurization waste liquid incineration acid-making flue gas, so that NOx contained in the acid-making flue gas generated by incineration of the desulfurization waste liquid is effectively removed, the furnace gas is purified, the purification effect and reliability of the flue gas acid-making section are improved, and the energy consumption is reduced. The quality of finished concentrated sulfuric acid is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of waste gas treatment, and specifically relates to a coking HPF desulfurization waste liquid incineration acid production flue gas treatment system. Background Art

[0002] At present, the coking industry in my country often uses the HPF method and PDS method with ammonia as the alkali source to desulfurize coke oven gas. Due to the complex composition of coal gas, complex components are produced during the desulfurization process, including sulfate, thiocyanate, thiosulfate and other secondary salt components, as well as a large amount of NO in the flue gas. x Impurities: When the secondary salts in the system accumulate to more than 250g / L, it will seriously affect the desulfurization effect. At the same time, the excess NO in the flue gas used for acid production in the system x It will affect the acid-making process of waste liquid incineration flue gas, containing NO x The acid-making flue gas enters the back-end acid-making system to make concentrated sulfuric acid. Incineration acid production has many problems, such as: pipeline blockage, reduced concentrated sulfuric acid production, abnormal concentrated sulfuric acid color and quality degradation. At the same time, the economic value of concentrated sulfuric acid has dropped significantly due to poor quality. Therefore, it is necessary to remove NO in the flue gas during the acid-making process of waste liquid incineration flue gas. x . Utility Model Content

[0003] The utility model aims to provide a flue gas treatment system for incinerating acid-making waste liquid from a coking HPF desulfurization plant, which can at least solve some of the defects existing in the prior art.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A flue gas treatment system for incinerating acid-making from coking HPF desulfurization waste liquid comprises an incinerator, a primary denitrification unit, a high-temperature dust purification mechanism and a secondary denitrification unit; the air outlet of the incinerator is connected to the air inlet of the primary denitrification unit, the air outlet of the primary denitrification unit is connected to the air inlet of the high-temperature dust purification mechanism, the air outlet of the high-temperature dust purification mechanism is connected to the air inlet of the secondary denitrification unit, and the air outlet of the secondary denitrification unit is externally connected to a flue gas acid-making section.

[0006] Furthermore, the primary denitrification unit includes a waste heat boiler, and an air inlet end of the waste heat boiler is provided with an ammonia injection mechanism for injecting ammonia into the flue gas entering the waste heat boiler.

[0007] Furthermore, the ammonia spraying mechanism includes a high-pressure atomizing spray gun and an ammonia water delivery pump, the high-pressure atomizing spray gun is arranged in the waste heat boiler, the ammonia water delivery pump is located outside the waste heat boiler, the inlet of the high-pressure atomizing spray gun is connected to the outlet of the ammonia water delivery pump, and the inlet of the ammonia water delivery pump is connected to the ammonia water station.

[0008] Furthermore, the waste heat boiler includes a first return high temperature section and a second return transition section, the first return high temperature section and the second return transition section are separated by a vertically arranged partition, and the top outlet of the first return high temperature section is connected to the inlet of the second return transition section, the bottom inlet of the first return high temperature section is connected to the air outlet of the incinerator, and the outlet of the second return transition section is connected to the high-temperature dust purification mechanism.

[0009] Furthermore, the ammonia injection outlet of the ammonia injection mechanism is located in the first return high temperature section.

[0010] Furthermore, the high-temperature dust purification mechanism is a high-temperature ceramic dust collector.

[0011] Furthermore, the secondary denitration unit comprises an SCR denitration reactor, and a first catalyst layer and a second catalyst layer are sequentially arranged at an inlet end of the SCR denitration reactor along a flue gas flow direction.

[0012] Furthermore, a high-temperature heat exchanger is provided between the secondary denitration unit and the flue gas acid-making section.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system provided by the utility model performs two-stage deep denitration treatment on the desulfurization waste liquid incineration acid production flue gas through a primary denitration unit and a secondary denitration unit, effectively removing NO contained in the acid production flue gas generated by the incineration of desulfurization waste liquid. x , purify furnace gas, improve the purification effect and reliability of the flue gas acid-making section, and improve the quality of finished concentrated sulfuric acid.

[0015] The present invention will be described in further detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the utility model of a coking HPF desulfurization waste liquid incineration acid production flue gas treatment system.

[0017] Explanation of the accompanying drawings: 1. Incinerator; 2. Waste heat boiler; 3. High-temperature ceramic dust collector; 4. SCR denitrification reactor; 5. High-temperature heat exchanger; 6. Ammonia water station; 7. Ammonia water delivery pump; 8. First return high-temperature section; 9. Partition; 10. Second return transition section; 11. High-pressure atomizing spray gun; 12. First catalyst layer; 13. Second catalyst layer. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of 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.

[0019] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, a conflicting connection or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present utility model, unless otherwise specified, "plurality" means two or more.

[0022] like Figure 1 As shown, this embodiment provides a flue gas treatment system for incineration of coking HPF desulfurization waste liquid to produce acid, comprising an incinerator 1, a primary denitrification unit, a high-temperature dust purification mechanism and a secondary denitrification unit; the gas outlet of the incinerator 1 is connected to the gas inlet of the primary denitrification unit, the gas outlet of the primary denitrification unit is connected to the gas inlet of the high-temperature dust purification mechanism, the gas outlet of the high-temperature dust purification mechanism is connected to the gas inlet of the secondary denitrification unit, and the gas outlet of the secondary denitrification unit is externally connected to the flue gas acid production section. During operation, the raw material of the coking HPF desulfurization waste liquid enters the incinerator 1 for incineration, and the flue gas generated by the incineration enters the primary denitrification unit for primary denitrification treatment. The flue gas after the primary denitrification treatment enters the high-temperature dust purification mechanism to remove a large amount of dust to purify the flue gas. At the same time, the flue gas is heated at high temperature to meet the denitrification temperature of the subsequent secondary denitrification unit. The purified flue gas enters the secondary denitrification unit for secondary deep denitrification to remove NO in the flue gas.x After the removal of NOx, the acid-making flue gas entering the flue gas acid-making section can stably produce qualified concentrated sulfuric acid and meet production standards. The coking HPF desulfurization waste liquid incineration acid-making flue gas treatment system provided in this embodiment performs two-stage deep denitrification treatment on the desulfurization waste liquid incineration acid-making flue gas through a primary denitrification unit and a secondary denitrification unit, effectively removing NO contained in the acid-making flue gas generated by the incineration waste liquid. x , purify furnace gas, improve the purification effect and reliability of the acid-making section, and improve the quality of finished concentrated sulfuric acid.

[0023] As a specific implementation, the primary denitration unit includes a waste heat boiler 2, and an ammonia injection mechanism is provided at the air inlet end of the waste heat boiler 2 for injecting ammonia into the flue gas entering the waste heat boiler 2. In this implementation, the SNCR denitration method is combined with the structural form of the waste heat boiler 2 to simplify the system structure and save investment costs.

[0024] Specifically, the ammonia spraying mechanism includes a high-pressure atomizing spray gun 11 and an ammonia water delivery pump 7. The high-pressure atomizing spray gun 11 is arranged in the waste heat boiler 2, and the ammonia water delivery pump 7 is located outside the waste heat boiler 2. The inlet of the high-pressure atomizing spray gun 11 is connected to the outlet of the ammonia water delivery pump 7, and the inlet of the ammonia water delivery pump 7 is connected to the ammonia water station 6; wherein the number of the ammonia water delivery pump 7 and the high-pressure atomizing spray gun 11 can be set according to actual needs.

[0025] Optimally, the waste heat boiler 2 is designed to include a first return high temperature section 8 and a second return transition section 10, the first return high temperature section 8 and the second return transition section 10 are separated by a vertically arranged partition 9, and the top outlet of the first return high temperature section 8 is connected to the inlet of the second return transition section 10, the bottom inlet of the first return high temperature section 8 is connected to the air outlet of the incinerator 2, and the outlet of the second return transition section 10 is connected to the high-temperature dust purification mechanism; wherein the high-pressure atomizing spray gun 11 of the ammonia spraying mechanism is arranged in the first return high temperature section 8. The flue gas (about 1050°C) generated by the incinerator 1 is sprayed with ammonia water (reducing agent) in the first return high temperature section 8 of the waste heat boiler 2 by a high-pressure atomizing spray gun 11 to perform primary SNCR denitrification to remove most of the NO in the flue gas. x , precipitated ammonium salts and some heavy metal ions, the temperature control range of this section is 850℃~1050℃, which can significantly improve the denitrification efficiency; and the waste heat boiler 2 is designed as a first return high temperature section 8 and a second return transition section 10. The flow path of the flue gas in the waste heat boiler 2 is increased, so that the first-level denitrification process of the flue gas in the waste heat boiler 2 can be more thorough, thereby improving the first-level denitrification effect.

[0026] Optionally, the high-temperature dust purification mechanism adopts a high-temperature ceramic dust collector 3.

[0027] As an embodiment, the secondary denitration unit includes an SCR denitration reactor 4, and the inlet end of the SCR denitration reactor 4 is provided with a first catalyst layer 12 and a second catalyst layer 13 in sequence along the flue gas flow direction. The flue gas after primary denitration passes through a high-temperature ceramic dust collector 3 and then enters the SCR denitration reactor 4, where NO is removed under high temperature conditions. x The SCR denitration reactor 4 contains two catalyst layers. In the primary denitration process, excessive ammonia water is sprayed into the waste heat boiler 2, so that the flue gas at the outlet of the waste heat boiler 2 contains ammonia water / ammonia gas. In the secondary denitration process, the catalyst in the SCR denitration reactor 4 reacts with the ammonia water / ammonia gas mixed in the flue gas to reduce the NO in the flue gas. x A secondary deep denitration reaction is carried out to improve the utilization rate of ammonia water (reducing agent); wherein, the operating temperature of the catalyst in the SCR denitration reactor 4 is 400°C to 420°C, which can withstand high temperature and high concentration of sulfur dioxide.

[0028] In this embodiment, the incineration of acid production flue gas can remove about 75% of NO by spraying ammonia denitrification in the first-stage SNCR. x After the second stage of deep denitrification, about 20% of NO is removed. x After the secondary deep denitrification, the quality of the finished acid is stable and the output of the finished acid is greatly increased.

[0029] Optimally, a high-temperature heat exchanger 5 is further provided between the secondary denitrification unit and the flue gas acid-making section. The flue gas treated with denitrification by the secondary denitrification unit enters the high-temperature heat exchanger 5 and undergoes heat exchange treatment through cooling air, thereby reducing the flue gas temperature to meet the temperature conditions of the flue gas acid-making section. At the same time, the flue gas can be used for waste heat recovery.

[0030] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are identical or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A coking HPF desulfurization waste liquid incineration acid production flue gas treatment system, characterized by: It includes an incinerator, a primary denitrification unit, a high-temperature dust purification mechanism and a secondary denitrification unit; the air outlet of the incinerator is connected to the air inlet of the primary denitrification unit, the air outlet of the primary denitrification unit is connected to the air inlet of the high-temperature dust purification mechanism, the air outlet of the high-temperature dust purification mechanism is connected to the air inlet of the secondary denitrification unit, and the air outlet of the secondary denitrification unit is externally connected to the flue gas acid production section.

2. The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system according to claim 1, characterized in that: The primary denitration unit comprises a waste heat boiler, and an air inlet end of the waste heat boiler is provided with an ammonia spraying mechanism for spraying ammonia on the flue gas entering the waste heat boiler.

3. The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system according to claim 2, characterized in that: The ammonia spraying mechanism includes a high-pressure atomizing spray gun and an ammonia water delivery pump. The high-pressure atomizing spray gun is arranged in the waste heat boiler, and the ammonia water delivery pump is located outside the waste heat boiler. The inlet of the high-pressure atomizing spray gun is connected to the outlet of the ammonia water delivery pump, and the inlet of the ammonia water delivery pump is connected to the ammonia water station.

4. The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system according to claim 2, characterized in that: The waste heat boiler includes a first return high temperature section and a second return transition section, the first return high temperature section and the second return transition section are separated by a vertically arranged partition, and the top outlet of the first return high temperature section is connected to the inlet of the second return transition section, the bottom inlet of the first return high temperature section is connected to the air outlet of the incinerator, and the outlet of the second return transition section is connected to the high-temperature dust purification mechanism.

5. The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system according to claim 4, characterized in that: The ammonia injection outlet of the ammonia injection mechanism is located in the first return high-temperature section.

6. The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system according to claim 1, characterized in that: The high-temperature dust purification mechanism is a high-temperature ceramic dust collector.

7. The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system according to claim 1, characterized in that: The secondary denitration unit comprises an SCR denitration reactor, and a first catalyst layer and a second catalyst layer are sequentially arranged at an inlet end of the SCR denitration reactor along a flue gas flow direction.

8. The coking HPF desulfurization waste liquid incineration acid production flue gas treatment system according to claim 1, characterized in that: A high-temperature heat exchanger is provided between the secondary denitration unit and the flue gas acid-making section.

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