A kind of waste incineration power plant sludge and alkali metal removal agent coupling dry method blending burning device

Abstract

The present application relates to a kind of sludge and alkali metal removal agent coupling dry method mixed burning device of waste incineration power plant, belong to garbage disposal technical field.The sludge drying system, dry powder mixing bin, dry powder fluidization bin, conveying air system, powder distribution unit, sludge nozzle and secondary air nozzle are sequentially connected and arranged, and the fluidization air system and purging air system are arranged on the dry powder fluidization bin;Secondary air nozzle is arranged in the high-temperature flue gas zone of furnace chamber;Secondary air nozzle is arranged in segments along the height of furnace chamber, and is uniformly arranged along the width of furnace chamber;Secondary air nozzle is arranged as high-position secondary air nozzle and low-position secondary air nozzle along the height of furnace chamber;High-position secondary air nozzle uses normal-temperature secondary air, low-position secondary air nozzle uses high-temperature primary air, and wind rate is adjustable.Through the present application, sludge high-temperature harmless treatment can be realized, and problems such as contamination and dust accumulation of heating surface can be inhibited.

Description

A dry co-firing device for waste incineration power plant sludge and alkali metal removal agent Technical Field

[0001] This invention relates to a dry co-firing device for sludge from a waste incineration power plant and an alkali metal removal agent, belonging to the field of waste treatment technology. Background Technology

[0002] Municipal solid waste incineration technology can reduce and render municipal solid waste harmless, and also achieve resource recovery through energy recycling. In the waste treatment process, sludge is a significant byproduct of leachate collection and treatment. Generally, collected sludge is sprayed back into the waste pit or hopper, mixed with the waste, and then treated harmlessly through high-temperature combustion. Current treatment methods have shortcomings in engineering applications, including: easy accumulation of sludge on the feeder, incomplete combustion, small processing capacity, and significant impact on combustion conditions. There is also the issue of some sludge being returned to the leachate recovery system. Furthermore, due to the relatively high content of alkali metals sodium and potassium in municipal solid waste, the combustion produces gaseous alkali metals and low-ash-melting-point fly ash, which easily form a sticky bottom layer on the heating surface, leading to ash deposition, blockage of the heating surface, and reduced heat transfer efficiency. Currently, there is no effective method to solve the problems of sludge treatment and ash deposition caused by alkali metals in waste-to-energy incineration plants. Therefore, there is an urgent need in this technical field for a device for high-temperature treatment of sludge and suppression of ash deposition on heated surfaces, which is of great significance for waste treatment and energy recovery. Summary of the Invention

[0003] The purpose of this invention is to solve the technical problem of how to obtain a device for the coupled dry co-firing of sludge and alkali metal removal agent, and how this device can simultaneously solve the technical problems of high-temperature harmless treatment of sludge from waste incineration power plants and the inhibition of alkali metal-induced fouling and ash accumulation.

[0004] To address the aforementioned problems, the present invention provides a dry co-firing device for waste incineration power plant sludge and alkali metal removal agent, comprising, in sequence, a sludge drying system, a dry powder mixing chamber, a dry powder fluidization chamber, a conveying air system, a powder distribution unit, sludge nozzles, and secondary air nozzles; the dry powder fluidization chamber is equipped with a fluidizing air system and a purging air system; the secondary air nozzles are located in the high-temperature flue gas zone of the furnace; the secondary air nozzles are arranged in segments along the height of the furnace and uniformly along the width of the furnace; the secondary air nozzles are configured as high-level secondary air nozzles and low-level secondary air nozzles along the height of the furnace; the high-level secondary air nozzles use ambient temperature secondary air, and the low-level secondary air nozzles use high-temperature primary air, with adjustable airflow rates.

[0005] Preferably, the moisture content of the dried sludge after passing through the sludge drying system is 10%-15%.

[0006] Preferably, the alkali metal removal agent is SiO2. 2、 Al2O3 or kaolin is used as an additive, and the amount of alkali metal removal agent used is 1%-15% of the ash content.

[0007] Preferably, the dry powder fluidizing chamber is connected to the outlet pipes of the fluidizing air system and the purging air system; the dry powder fluidizing chamber is equipped with a weighing device for weight monitoring, a pressure balancing pipe for pressure balancing, a safety valve and a vent valve; the outlet of the dry powder fluidizing chamber is equipped with a shut-off valve group and a feeder; the dry powder fluidizing chamber adopts an intermittent powder feeding method.

[0008] Preferably, the shut-off valve assembly is in the normally closed state.

[0009] Preferably, the high-level secondary air nozzles have ≥2 layers and are arranged in the first flue at the furnace outlet; the low-level secondary air nozzles have ≥2 layers, with at least one layer of low-level secondary air nozzles arranged on the front arch wall and the rear arch wall; the spraying area of ​​the secondary air nozzles on the front arch wall and the rear arch wall is above the drying section and the combustion section.

[0010] Preferably, the sludge nozzle is located inside the low-level secondary air nozzle, and the two are arranged coaxially.

[0011] Preferably, the temperature range of the conveying air used in the low-level secondary air nozzle is 150℃-350℃, the air rate is 5%-15%, and it originates from the air preheater outlet.

[0012] Preferably, the air supplied by the high-level secondary air nozzle is ambient temperature air, with an airflow rate of 2%-25%.

[0013] Preferably, the high-level secondary air nozzles and low-level secondary air nozzles are arranged in layers according to the working conditions to ensure that the flue gas temperature in the first flue is higher than 850°C.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The sludge and alkali metal removal agent coupled co-firing device can realize the high-temperature harmless treatment of sludge and inhibit the problems of fouling and ash accumulation on the heated surface;

[0016] 2. The use of gas transport method to achieve dry high-temperature harmless treatment of sludge ensures that the dry sludge powder is evenly sprayed into the high-temperature zone, avoiding sludge clumping and uneven spraying in the feeder, which seriously affects the load and causes long adjustment cycles.

[0017] 3. The gas transport system is flexible and can quickly adjust the amount of sludge re-injection according to the combustion status of the waste in the furnace.

[0018] 4. The use of air at different temperatures for high-level and low-level secondary air can stabilize the combustion conditions of waste in the furnace by controlling the airflow rate, and can achieve a certain degree of oil-free co-firing.

[0019] 5. Integrating the sludge and alkali metal removal agent into the two systems and combining them with the secondary air system can effectively utilize the narrow space in front of the furnace arch, reducing equipment investment costs and operating costs. Attached Figure Description

[0020] Figure 1 is a schematic diagram of the system structure of the present invention;

[0021] Figure 2 is a schematic diagram of the gas transport system of the present invention;

[0022] Figure 3 is a schematic diagram of the secondary air nozzle arrangement of the present invention;

[0023] Figure 4 is a schematic diagram of the arrangement of the sludge nozzle and the secondary air nozzle of the present invention; Detailed Implementation

[0024] To make the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings:

[0025] As shown in Figures 1-4, the technical solution adopted by this invention is to provide a dry co-firing device for waste incineration power plant sludge and alkali metal removal agent, comprising a sludge drying system 500, a dry powder mixing chamber 606, a dry powder fluidization chamber 609, a conveying air system 610, a powder distribution unit 618, a sludge nozzle 619, and a secondary air nozzle 620 connected in sequence. The dry powder fluidization chamber 609 is equipped with a fluidizing air system 611 and a purging air system 612. The secondary air nozzles are located in the high-temperature flue gas zone of the furnace 300. The secondary air nozzles 620 are arranged in segments along the height of the furnace and uniformly along the width of the furnace. The secondary air nozzles are configured as a high-level secondary air nozzle 201 and a low-level secondary air nozzle 202 along the height of the furnace. The high-level secondary air nozzle 201 uses ambient temperature secondary air, and the low-level secondary air nozzle 202 uses high-temperature primary air, with adjustable airflow rates. The sludge 601 has a moisture content of 10%-15% after passing through the sludge drying system 500. Alkali metal removal agent 602 is selected from SiO 2、Al2O3 or kaolin is used as an additive, and the amount of alkali metal removal agent used is 1%-15% of the ash content. The dry powder fluidized bed 609 is connected to the outlet pipes of the fluidizing air system 611 and the purging air system 612. The dry powder fluidized bed 609 is equipped with a weighing device 608 for weight monitoring, a pressure balancing pipe for pressure balancing, a safety valve, and a vent valve 626. The outlet of the dry powder fluidized bed 609 is equipped with a shut-off valve assembly 624 and a feeder 613. The dry powder fluidized bed 609 adopts an intermittent powder feeding method. The shut-off valve assembly 624 / 625 is normally closed. The high-level secondary air nozzles 201 are arranged in at least two layers within the first flue gas duct 305 at the furnace outlet. The low-level secondary air nozzles 202 are arranged in at least two layers, with at least one layer located on the front arch wall 301 and the rear arch wall 302. The spray area of ​​the secondary air nozzles on the front arch wall 301 and the rear arch wall 302 is above the drying section 304 and the combustion section 303. Sludge nozzles 619 are located within the low-level secondary air nozzles 202, and the two are arranged coaxially. The conveying air 610 used by the low-level secondary air nozzles 202 has a temperature range of 150℃-350℃ and an airflow rate of 5%-15%, originating from the air preheater outlet. The conveying air 200 used by the high-level secondary air nozzles 201 is ambient temperature air with an airflow rate of 2%-25%. The high-level secondary air nozzles 201 and low-level secondary air nozzles 202 are arranged in layers according to operating conditions to ensure that the flue gas temperature within the first flue gas duct 305 is above 850℃.

[0026] This invention provides an apparatus for the coupled dry co-firing of sludge and alkali metal removal agent, comprising a sludge drying system 500, a dry powder mixing chamber 606, a dry powder fluidization chamber 609, a conveying air system 610, a fluidizing air system 611, a purging air system 612, a powder distribution unit 618, a sludge nozzle 619, and a secondary air nozzle 620. The alkali metal removal agent 602 and the sludge 601 dried by the sludge drying system 500 are mixed in the dry powder mixing chamber 606 via a vibrating metal mesh 603, and then enter the dry powder fluidization chamber 609 via a shut-off valve group 624. The sludge is fluidized by primary air 101 through the fluidizing air system 611. After fluidization, the fluidized sludge is conveyed by the conveying air system 610 through a distributor 618 to the sludge nozzle 619, which connects to the secondary air nozzle 620 and enters the high-temperature flue gas zone of the furnace 300, where it is heated by the flue gas and undergoes combustion, adsorption, and other reactions. The dry powder mixing chamber 606 includes a vibrating metal mesh 603, a dust collector 604, a temperature sensor 605, and a sampler 607.

[0027] The dry powder fluidization chamber 609 is connected to the outlet pipes of the fluidizing air system 611 and the purging air system 612; the dry powder fluidization chamber 609 is equipped with a weighing device 608 for weight monitoring, a pressure balancing pipe 622 for pressure balancing, a safety valve, a vent valve 626, and other devices; the outlet of the dry powder fluidization chamber 609 is equipped with a shut-off valve group 625 and a feeder 613.

[0028] Hot air from primary air 102 is mixed with fluidized dry powder at the outlet of conveying air system 610 and feeder 613 in mixer 614 and distributed to sludge nozzle 619 by distributor 618.

[0029] The secondary air nozzles 620 are arranged in segments along the height and evenly along the width of the furnace. The high-level secondary air nozzle 201 uses ambient temperature secondary air, while the low-level secondary air nozzle 202 uses high temperature primary air. The air rates of the high-level secondary air nozzle 201 and the low-level secondary air nozzle 202 are adjustable.

[0030] Alkali metal removal agent 602 is silicon dioxide (SiO2), aluminum oxide (Al2O3), or kaolin and mixtures thereof.

[0031] The moisture content of the dried sludge 601 after passing through the drying system 500 is 10%-15%.

[0032] SiO2 or kaolin is selected as the additive for alkali metal removal agent, and the amount of alkali metal removal agent used is 1%-15% of the ash content of the waste.

[0033] The shut-off valve groups 624 and 625 are normally closed. The dried sludge 601 and alkali metal removal agent 602 enter the dry powder fluidization chamber 609 through the shut-off valve 624. The fluidized dry powder enters the furnace intermittently according to the actual operating conditions of the furnace.

[0034] The high-level secondary air nozzles 201 have ≥2 layers and are arranged in the first flue 305 at the furnace outlet.

[0035] The number of layers of low-level secondary air nozzles 202 is ≥2, with at least one layer of secondary air nozzles arranged on the front arch wall 301 and the rear arch wall 302. The spraying area of ​​the dry powder from the secondary air nozzles (201, 202) on the front arch wall 301 and the rear arch wall 302 is above the drying section 304 and the combustion section 303, and directly participates in the combustion process of the high-temperature gas above the drying section 304 and the combustion section 303.

[0036] The sludge nozzle 619 is placed inside the low-level secondary air nozzle 202, and the two are arranged coaxially.

[0037] The temperature range of the conveying air 610 used in the low-level secondary air nozzle is 150℃-350℃, and the air rate is 5%-15%, which comes from the air preheater outlet.

[0038] The air supplied to the high-level secondary air nozzle is ambient temperature air, with an airflow rate of 2%-25%.

[0039] The high-level secondary air nozzle 201 and the low-level secondary air nozzle 202 are arranged in layers according to the working conditions to ensure that the flue gas temperature in the first flue duct 305 is higher than 850℃.

[0040] Example

[0041] As shown in Figures 1 to 4, this invention provides a dry combustion device for coupled sludge and alkali metal removal in a waste-to-energy incineration plant. The device includes a sludge drying system 500, a dry powder mixing chamber 606, a dry powder fluidization chamber 609, a conveying air system 610, a fluidizing air system 611, a purging air system 612, a powder distribution unit 618, sludge nozzles 619, and secondary air nozzles 620. The alkali metal removal agent 602 and the sludge 601 dried by the sludge drying system 500 are thoroughly mixed in the dry powder mixing chamber 606 via a vibrating metal mesh 603. After mixing, the mixture passes through a shut-off valve group 624 and enters the dry powder fluidization chamber 609. Primary air 101 is used as the fluidizing air, which is then used in the fluidizing air system 611 for fluidization. After fluidization, the fluidized sludge is conveyed by the conveying air system 610 through a distributor 618 to each sludge nozzle 619, which connects to the secondary air nozzles 620. The fluidized sludge then enters the high-temperature flue gas zone of the furnace 300, where it is heated and undergoes combustion and adsorption reactions with the flue gas. The dry powder mixing chamber 606 includes a vibrating metal mesh 603, a dust collector 604, a temperature sensor 605, a sampler 607, and a manhole. The dry powder fluidization chamber 609 is connected to the outlet pipes of the fluidizing air system 611 and the purging air system 612. The dry powder fluidization chamber 609 is equipped with a weighing device 608 for weight monitoring, a pressure balancing pipe 622 for pressure balancing, a safety valve, a vent valve 626, and other devices. The outlet of the dry powder fluidization chamber is equipped with a shut-off valve group 625 and a feeder 613. Hot air from the primary air 102 is mixed with fluidized dry powder at the outlet of the conveying air system 610 and the feeder 613 in the mixer 614 and then distributed to the sludge nozzle 619 by the distributor 618. The alkali metal removal agent 602 can be silicon dioxide (SiO2), aluminum oxide (Al2O3), or kaolin, or a mixture of both. The secondary air nozzles 620 are arranged in segments along the height and evenly along the width of the furnace. The high-level secondary air nozzle 201 uses ambient temperature secondary air, while the low-level secondary air nozzle 202 uses high temperature primary air. The air rates of the high-level and low-level secondary air are adjustable.

[0042] The moisture content of the dried sludge 601 after passing through the drying system 500 is 10%-15%.

[0043] For alkali metal removal agents, SiO2, Al2O3, or kaolin are selected as additives, and the dosage of the alkali metal removal agent is 1%-15% of the ash content of the waste. The appropriate formula is selected according to the composition of the waste.

[0044] The shut-off valve groups 624 and 625 are normally closed. After the shut-off valve 624 is opened, the dried mixed dry powder (601, 602) enters the fluidized powder hopper through the shut-off valve 624. Then the shut-off valve 624 is closed, and the mixed dry powder (601, 602) is fully fluidized by the fluidizing air 611. Then the shut-off valve 625 is opened, and the powder enters the furnace according to the actual operation of the furnace.

[0045] The sludge nozzle 619 is placed inside the low-level secondary air nozzle 202, and the two are arranged coaxially.

[0046] The high-level secondary air nozzles 201 have ≥2 layers and are arranged in the first flue 305 at the furnace outlet.

[0047] The number of layers of low-level secondary air nozzles 202 is ≥2, with at least one layer of secondary air nozzles arranged on the front arch wall 301 and the rear arch wall 302. The secondary air nozzles (201, 202) on the front arch wall 301 and the rear arch wall 302 spray dry powder (601, 602) in the area above the drying section 304 and the combustion section 303, directly participating in the combustion process of the high-temperature gas above the drying section 304 and the combustion section 303.

[0048] The conveying air 610 used in the low-level secondary air nozzle has a temperature range of 150℃-350℃ and an air rate of 5%-15%, originating from the air preheater outlet. Preferably, the air rate is 5%-10% and the temperature range is 150℃-250℃.

[0049] The air supplied to the high-level secondary air nozzle is ambient temperature air, with an airflow rate of 2%-25%.

[0050] The high-level secondary air nozzle 201 and the low-level secondary air nozzle 202 are arranged in layers according to the working conditions to ensure that the flue gas temperature in the first flue duct 305 is higher than 850℃.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A dry co-firing device for sludge from a waste incineration power plant and an alkali metal removal agent, characterized in that, The system includes a sludge drying system, a dry powder mixing chamber, a dry powder fluidization chamber, a conveying air system, a powder distribution unit, sludge nozzles, and secondary air nozzles, all connected in sequence. The dry powder fluidization chamber is equipped with a fluidizing air system and a purging air system. The secondary air nozzles are located in the high-temperature flue gas zone of the furnace. The secondary air nozzles are arranged in segments along the height of the furnace and uniformly along its width. The secondary air nozzles are divided into high-level and low-level nozzles along the height of the furnace. The high-level secondary air nozzles use ambient temperature secondary air, while the low-level secondary air nozzles use high-temperature primary air, with adjustable airflow rates. The alkali metal removal agent and the sludge dried by the sludge drying system are mixed in the dry powder mixing chamber and then enter the dry powder fluidization chamber. The fluidized sludge is fluidized by the fluidizing air system. After fluidization, the sludge is conveyed by the conveying air system through the powder distribution unit to the sludge nozzles, which connect to the secondary air nozzles, and then enter the high-temperature flue gas zone of the furnace, where it is heated by the flue gas and reacts with it.

2. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The sludge has a moisture content of 10%-15% after passing through the sludge drying system.

3. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The alkali metal removal agent is selected from SiO₂. 2、 Al2O3 or kaolin is used as an additive, and the amount of alkali metal removal agent used is 1%-15% of the ash content.

4. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The dry powder fluidized bed is connected to the outlet pipes of the fluidizing air system and the purging air system; the dry powder fluidized bed is equipped with a weighing device for weight monitoring, a pressure balancing pipe for pressure balancing, a safety valve and a vent valve; the outlet of the dry powder fluidized bed is equipped with a shut-off valve group and a feeder; the dry powder fluidized bed adopts an intermittent powder feeding method.

5. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 4, characterized in that, The shut-off valve assembly is set to the normally closed state.

6. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The high-level secondary air nozzles have ≥2 layers and are arranged in the first flue at the furnace outlet; the low-level secondary air nozzles have ≥2 layers, with at least one layer of low-level secondary air nozzles arranged on the front and rear arch walls; the spraying area of ​​the secondary air nozzles on the front and rear arch walls is above the drying and combustion sections.

7. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The sludge nozzle is located inside the low-level secondary air nozzle, and the two are arranged coaxially.

8. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The temperature range of the conveying air used in the low-level secondary air nozzle is 150℃-350℃, and the air rate is 5%-15%, originating from the air preheater outlet.

9. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The high-level secondary air nozzle uses ambient temperature air as the delivery air, with an airflow rate of 2%-25%.

10. The dry co-firing device for waste incineration power plant sludge and alkali metal removal agent according to claim 1, characterized in that, The high-level secondary air nozzles and low-level secondary air nozzles are arranged in layers according to the working conditions to ensure that the flue gas temperature in the first flue is higher than 850°C.

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