Purification system suitable for sludge and biomass incineration flue gas

Abstract

The utility model provides a purification system suitable for sludge and biomass incineration flue gas, which can synchronously perform deacidification, denitration, dust removal and dioxin and heavy metal removal, and meets the ultra-low emission requirement. The limestone powder bin and the SNCR ammonia water storage tank are both connected with the incinerator; the incinerator is connected with the waste heat boiler; the waste heat boiler is connected with the deacidification reactor through a high-temperature flue, the deacidification reactor is connected with the high-temperature dust remover, and the high-temperature dust remover is connected with the SCR reactor; the calcium hydroxide powder bin I and the SCR ammonia water storage tank are both connected with the high-temperature flue; the SCR reactor, the low-temperature economizer and the air pre-heater are connected in sequence; the air pre-heater is connected with the bag-type dust remover through a bag-type dust removal inlet flue; both the calcium hydroxide powder bin II and the activated carbon bin are connected with the cloth bag dust removal inlet flue; the bag-type dust collector is connected with the induced draft fan; the induced draft fan is connected with the wet deacidification tower; the wet deacidification tower is connected with a chimney; and the sodium hydroxide solution storage tank is connected with the wet deacidification tower.

Description

Technical Field

[0001] The utility model relates to a purification system suitable for sludge and biomass incineration flue gas, which can be applied to the field of sludge and biomass incineration power generation. Background Art

[0002] The main methods of sludge disposal are land utilization, landfill and incineration. Land utilization and incineration are the main methods in Europe and the United States. More than 50% of sludge in Japan is incinerated. In my country, sludge landfill accounts for the highest proportion, and incineration accounts for only 5%. In summary, converting sludge into usable energy and achieving the maximum reduction and resource utilization of sludge are in line with the principles of sludge disposal. Therefore, sludge incineration power generation will be an important direction for sludge disposal in my country in the future.

[0003] As a renewable energy source, biomass has become the fourth largest energy source after oil, natural gas and coal. my country is very rich in biomass resources. For example, the volume of straw in rural my country is large, the types are diverse and the distribution is wide. The annual straw production reaches 700 million tons, which is equivalent to 350 million tons of standard coal, accounting for about 30% of the total global straw. Compared with traditional fossil fuels, the development of biomass power generation can significantly reduce CO2 and SO2 emissions and produce huge environmental benefits.

[0004] Due to the diversity of sludge and biomass, the composition of flue gas after incineration is complex. In order to ensure that the pollutants in the flue gas meet the emission standards after incineration, there is an urgent need for a purification process suitable for sludge and biomass incineration flue gas that can meet ultra-low emission requirements. Utility Model Content

[0005] The purpose of the utility model is to overcome the above-mentioned deficiencies in the prior art and to provide a purification system with a reasonable structural design suitable for sludge and biomass incineration flue gas, which can simultaneously deacidify, denitrify, remove dust, remove dioxins and heavy metals, and meet ultra-low emission requirements.

[0006] The technical solution adopted by the utility model to solve the above problems is: a purification system suitable for sludge and biomass incineration flue gas, characterized in that: it includes a limestone powder bin, a calcium hydroxide powder bin 1, a calcium hydroxide powder bin 2, a wet deacidification tower, a sodium hydroxide solution storage tank, a deacidification reactor, an SNCR ammonia water storage tank, an SCR ammonia water storage tank, an SCR reactor, a high-temperature dust collector, a bag dust collector, an activated carbon bin, a high-temperature flue and a bag dust collection inlet flue; the limestone powder bin and the SNCR ammonia water storage tank are both connected to the incinerator; the incinerator is connected to the waste heat boiler; the waste heat boiler is connected to the waste heat boiler; The super-high temperature flue is connected to the deacidification reactor, the deacidification reactor is connected to the high-temperature dust collector, and the high-temperature dust collector is connected to the SCR reactor; the calcium hydroxide powder silo one and the SCR ammonia water storage tank are both connected to the high-temperature flue; the SCR reactor, the low-temperature economizer, and the air preheater are connected in sequence; the air preheater is connected to the bag dust collector through the bag dust collection inlet flue; the calcium hydroxide powder silo two and the activated carbon silo are both connected to the bag dust collection inlet flue; the bag dust collector is connected to the induced draft fan; the induced draft fan is connected to the wet deacidification tower; the wet deacidification tower is connected to the chimney; the sodium hydroxide solution storage tank is connected to the wet deacidification tower.

[0007] The utility model also comprises a high-temperature powder bin, which is connected with a high-temperature dust removal hopper of a high-temperature dust collector.

[0008] The utility model also comprises a high-temperature dust conveying pipeline, which is located at the bottom of the high-temperature dust collector, and the high-temperature powder bin is connected to the high-temperature dust hopper of the high-temperature dust collector through the high-temperature dust conveying pipeline.

[0009] The utility model also comprises a normal temperature powder bin, which is connected with a bag dust removal hopper of a bag dust collector.

[0010] The utility model also comprises a silo pump delivery pipeline, which is located at the bottom of the bag dust collector, and the normal temperature powder silo is connected with the bag dust hopper of the bag dust collector through the silo pump delivery pipeline.

[0011] The top of the wet deacidification tower described in the utility model is provided with a tube bundle type demisting and dust removing device.

[0012] The incinerator of the utility model is provided with a plurality of ammonia water injection points.

[0013] The chimney of the utility model is provided with pollutant online monitoring equipment.

[0014] Compared with the prior art, the utility model has the following advantages and effects:

[0015] (1) This system can simultaneously remove acid, nitrogen, dust, dioxins and heavy metals to meet ultra-low emission requirements.

[0016] (2) 4-step deacidification: dry deacidification in the furnace, high-temperature dry deacidification, medium-temperature dry deacidification and wet spray deacidification work together to cope with changes in pollutant concentration under load fluctuations, ensure the stable operation of the incineration system, and ensure that the outlet SO2 is 35mg / Nm 3 Within.

[0017] (3) Three-step dust removal: high-temperature dust removal, bag dust removal and tube bundle type mist removal are interspersed between the deacidification and denitration processes, creating good basic reaction conditions for the deacidification and denitration processes. Dust removal is carried out in sections and regions to ensure that the outlet dust is 5mg / Nm 3 Within.

[0018] (4) Two-step denitrification: SNCR denitrification and SCR denitrification, fully utilizing the original temperature conditions, complementing each other, and ensuring the outlet NO x At 50mg / Nm 3 Within.

[0019] (5) One-step adsorption of heavy metals and dioxins: Utilizing the adsorption characteristics of activated carbon and combining it with bag dust removal, heavy metals and dioxins in incineration flue gas can be fully removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic structural diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and through examples. The following examples are provided to explain the present invention, but the present invention is not limited to the following examples.

[0022] The embodiment of the utility model comprises a limestone powder silo 1.1, a limestone conveying and spraying pipeline 1.2, a calcium hydroxide powder silo 1.3, a calcium hydroxide conveying and spraying pipeline 1.4, a calcium hydroxide powder silo 2 1.5, a calcium hydroxide conveying and spraying pipeline 2 1.6, a wet deacidification tower 1.7, a sodium hydroxide solution storage tank 1.8, a sodium hydroxide conveying pipeline 1.9, a deacidification reactor 1.10, an SNCR ammonia water storage tank 2.1, an SNCR ammonia water conveying pipeline 2.2, an SCR ammonia water storage tank 2.3, an SCR ammonia water conveying pipeline 2.4, an SCR reactor 2.5, a high-temperature dust collector 3.1, a high-temperature dust conveying pipeline 3.2, a high-temperature powder silo 3.3, a bag dust collector 3.4, a silo pump conveying pipeline 3.5, a normal temperature powder silo 3.6, a tube bundle type demisting dust collector 3.7, an activated carbon silo 4.1 and an activated carbon conveying pipeline 4.2.

[0023] The limestone powder silo 1.1 is connected to the incinerator 5.1 through the limestone delivery injection pipeline 1.2. The limestone powder is selected to be 250 mesh and is delivered by a Roots blower under positive pressure. The SNCR ammonia water storage tank 2.1 is connected to the incinerator 5.1 through the SNCR ammonia water delivery pipeline 2.2. Multiple ammonia water injection points are set on the incinerator 5.1. The incinerator 5.1 is connected to the waste heat boiler 5.2.

[0024] The waste heat boiler 5.2 is connected to the deacidification reactor 1.10 through the high-temperature flue 6.1, the deacidification reactor 1.10 is connected to the high-temperature dust collector 3.1 through the high-temperature dust removal inlet flue 6.2, and the high-temperature dust collector 3.1 is connected to the SCR reactor 2.5 through the high-temperature dust removal outlet flue 6.3. The flue gas flow rate in the deacidification reactor 1.10 is selected to be 4-6m / s, and the residence reaction time is about 4-6 seconds. The calcium hydroxide powder silo 1.3 is connected to the high-temperature flue 6.1 through the calcium hydroxide delivery injection pipeline 1.4; the calcium hydroxide powder is weighed and metered and then conveyed by a Roots blower under positive pressure.

[0025] The SCR reactor 2.5, low-temperature economizer 5.3, and air preheater 5.4 are connected in sequence, and the air preheater 5.4 is connected to the bag filter 3.4 through the bag filter inlet flue 6.4. The SCR ammonia water storage tank 2.3 is connected to the high-temperature flue 6.1 through the SCR ammonia water delivery pipeline 2.4. The reducing agent ammonia water required for SCR denitration is added at the high-temperature flue 6.1 and reaches the SCR reactor 2.5 after being fully mixed. The SCR reactor 2.5 is equipped with a catalyst and a soot blower. Under the action of the catalyst, SCR denitration is completed.

[0026] The calcium hydroxide powder bin 2 1.5 is connected to the bag dust collection inlet flue 6.4 through the calcium hydroxide delivery injection pipeline 2 1.6. The calcium hydroxide powder is weighed and metered and then conveyed by a Roots blower under positive pressure. The activated carbon bin 4.1 is connected to the bag dust collection inlet flue 6.4 through the activated carbon delivery pipeline 4.2. The activated carbon sprayed into the flue absorbs heavy metals and dioxins in the incineration flue gas.

[0027] The bag filter 3.4 is connected to the induced draft fan 5.5 through the bag filter outlet flue, the induced draft fan 5.5 is connected to the wet deacidification tower 1.7 through the induced draft fan outlet flue 6.6, the wet deacidification tower 1.7 is connected to the chimney 5.6 through the wet tower outlet flue 6.7, and the chimney 5.6 is provided with a pollutant online monitoring device 5.7. The sodium hydroxide solution storage tank 1.8 is connected to the wet deacidification tower 1.7 through the sodium hydroxide delivery pipeline 1.9, and the sodium hydroxide solution is added to the wet deacidification tower 1.7 according to the pH indication to complete the deacidification reaction. The flue gas flow rate in the wet deacidification tower 1.7 is selected to be 3.5m / s, and a multi-layer alkali solution spraying facility is provided inside; the wet deacidification tower 1.7 adopts glass flakes for corrosion protection, and a salinity meter is provided inside the tower. When the chloride ion concentration is higher than a certain value, the treated slurry is automatically discharged.

[0028] The high temperature dust conveying pipeline 3.2 is located at the bottom of the high temperature dust collector 3.1. The high temperature powder bin 3.1 is connected to the high temperature dust hopper of the high temperature dust collector 3.1 through the high temperature dust conveying pipeline 3.2. The temperature range of the high temperature dust collector 3.1 is 350-400 degrees. It uses a metal filter bag made of 2205. The high temperature dust collected by the hopper is transported by the Roots blower and stored in the high temperature powder bin 3.3.

[0029] The silo pump delivery pipeline 3.5 is located at the bottom of the bag dust collector 3.4, and the normal temperature powder silo 3.6 is connected to the bag dust hopper of the bag dust collector 3.4 through the silo pump delivery pipeline 3.5. The temperature range of the bag dust collector 3.4 is 150-200 degrees, and the filtering wind speed is 0.75m / s; the normal temperature dust collected by the hopper is transported by compressed air and enters the normal temperature powder silo 3.6 for storage.

[0030] A tube bundle type demisting and dust collecting device 3.7 is arranged on the top of the wet deacidification tower 1.7, and the incineration flue gas absorbed by the alkali solution spraying is again removed from the mist droplets and dust in the tube bundle type demisting and dust collecting device 3.7.

[0031] The operation method of the utility model is:

[0032] (1) The pollutants in the incineration flue gas are firstly subjected to the first step of dry deacidification and the first step of SNCR denitrification in the incinerator 5.1 at a temperature range of 800-1000 degrees.

[0033] (2) Calcium hydroxide powder and SCR reducing agent ammonia water are sprayed into the high-temperature flue 6.1 at 350-400 degrees, and the second step of high-temperature dry deacidification is completed in the deacidification reactor 1.10.

[0034] (3) The first step high temperature dust collector 3.1 can collect smoke, byproducts of the deacidification reaction and unreacted calcium hydroxide, providing conditions for the subsequent SCR denitrification. The second step SCR denitrification is completed in the SCR reactor 2.5.

[0035] (4) After the incineration flue gas passes through the low-temperature economizer 5.3 and the air preheater 5.4, the temperature is reduced to between 150 and 200 degrees. Calcium hydroxide powder and activated carbon are sprayed into the bag filter inlet flue 6.4 to complete the third step of medium-temperature dry deacidification and the first step of adsorption of heavy metals and dioxins.

[0036] (5) The second step bag filter 3.4 can collect smoke, by-products of the deacidification reaction, unreacted calcium hydroxide, activated carbon that adsorbs heavy metals and dioxins, etc.

[0037] (6) Under the action of the induced draft fan 5.5, the fourth step of wet spray deacidification is completed in the wet deacidification tower 1.7, and the third step of dust removal is completed after passing through the tube bundle type mist collector 3.7.

[0038] (7) In summary, after 4 steps of deacidification, 3 steps of dust removal, 2 steps of denitrification and 1 step of adsorption of heavy metals and dioxins, the incineration flue gas can meet the emission standards.

[0039] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the utility model. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the utility model are included in the protection scope of the utility model patent. Technicians in the technical field of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the utility model or exceed the scope defined by the claims, they should all fall within the protection scope of the utility model.

Claims

1. A purification system suitable for sludge and biomass incineration flue gas, characterized by: It includes limestone powder silo, calcium hydroxide powder silo 1, calcium hydroxide powder silo 2, wet deacidification tower, sodium hydroxide solution storage tank, deacidification reactor, SNCR ammonia storage tank, SCR ammonia storage tank, SCR reactor, high-temperature dust collector, bag dust collector, activated carbon silo, high-temperature flue and bag dust collection inlet flue; limestone powder silo and SNCR ammonia storage tank are connected to the incinerator; the incinerator is connected to the waste heat boiler; the waste heat boiler is connected to the deacidification reactor through the high-temperature flue, and the deacidification reactor is connected to the high-temperature dust collector The high-temperature dust collector is connected to the SCR reactor; the calcium hydroxide powder silo one and the SCR ammonia storage tank are both connected to the high-temperature flue; the SCR reactor, the low-temperature economizer, and the air preheater are connected in sequence; the air preheater is connected to the bag dust collector through the bag dust collection inlet flue; the calcium hydroxide powder silo two and the activated carbon silo are both connected to the bag dust collection inlet flue; the bag dust collector is connected to the induced draft fan; the induced draft fan is connected to the wet deacidification tower; the wet deacidification tower is connected to the chimney; the sodium hydroxide solution storage tank is connected to the wet deacidification tower.

2. The purification system for sludge and biomass incineration flue gas according to claim 1, characterized in that: It also includes a high-temperature powder bin, which is connected to a high-temperature dust hopper of a high-temperature dust collector.

3. The purification system for sludge and biomass incineration flue gas according to claim 2, characterized in that: It also includes a high-temperature dust conveying pipeline, which is located at the bottom of the high-temperature dust collector. The high-temperature powder bin is connected to the high-temperature dust hopper of the high-temperature dust collector through the high-temperature dust conveying pipeline.

4. The purification system for sludge and biomass incineration flue gas according to claim 1, characterized in that: It also includes a normal temperature powder bin, which is connected to a bag dust collector hopper of a bag dust collector.

5. The purification system for sludge and biomass incineration flue gas according to claim 4, characterized in that: It also includes a silo pump delivery pipeline, which is located at the bottom of the bag dust collector. The normal temperature powder silo is connected to the bag dust hopper of the bag dust collector through the silo pump delivery pipeline.

6. The purification system for sludge and biomass incineration flue gas according to claim 1, characterized in that: A tube bundle type mist remover and dust collector is arranged on the top of the wet deacidification tower.

7. The purification system for sludge and biomass incineration flue gas according to claim 1, characterized in that: The incinerator is provided with a plurality of ammonia water injection points.

8. The purification system for sludge and biomass incineration flue gas according to claim 1, characterized in that: The chimney is provided with online pollutant monitoring equipment.

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