Boiler fly ash recycling system

Abstract

The utility model discloses a boiler fly ash recycling system which comprises a boiler, a first dust remover and a separator, the first dust remover is connected with the boiler so as to process smoke generated by the boiler, and the separator is connected with the first dust remover and the boiler. The separator receives the dust discharged by the first dust remover and divides the dust into large-particle-size dust particles and small-particle-size dust particles, and the small-particle-size dust particles are used for being input into a boiler. According to the technical scheme, the flue gas generated by the boiler is treated through the first dust remover to obtain dust, the treated flue gas is discharged into the atmosphere, the dust is separated through the separator to obtain large-particle-size dust particles and small-particle-size dust particles, the small-particle-size dust particles are input into the boiler again, the specific surface area of the small-particle-size dust particles is large, and the specific surface area of the small-particle-size dust particles is large. The alkali metal steam can be better adsorbed in a boiler and can be discharged out of the boiler along with smoke generated by the boiler, and the slagging and contamination phenomena of the wall of the boiler are relieved through circulation of a large number of small-particle-size dust particles.

Description

Technical Field

[0001] The present application relates to the technical field of thermal power generation equipment, and in particular to a boiler fly ash recycling system. Background Art

[0002] Thermal power generation uses coal for combustion. Generally speaking, the coal needs to be crushed into coal powder and burned in the boiler. When the coal powder is burned, a large amount of alkali metals can easily cause slagging of the boiler water-cooled wall and contamination of the tail flue heat exchange tubes, thereby reducing the boiler efficiency.

[0003] In order to solve the problem of boiler slagging and fouling, the relevant technologies mainly adopt methods such as anti-corrosion spraying of the heating surface in the furnace, increasing the number of sootblowers and the frequency of sootblowers, and mixing kaolin. Anti-corrosion spraying of the heating surface in the furnace and increasing the number of sootblowers are passive measures, and cannot efficiently and economically solve the problems of boiler slagging and fouling. Mixing kaolin can improve boiler fouling and slagging, but the price of kaolin is relatively high. When mixed with kaolin in the boiler, the price per ton of kaolin is much higher than the price of coal, and the economic benefits are poor. Utility Model Content

[0004] The present application aims to solve the technical problems in the related art at least to a certain extent. To this end, the present application proposes a boiler fly ash recycling system, which can reduce slagging and contamination when the boiler is burning coal.

[0005] To achieve the above objectives, the present application discloses a boiler fly ash recycling system, comprising:

[0006] boiler;

[0007] a first dust collector connected to the boiler to process flue gas generated by the boiler; and

[0008] A separator, the separator is connected to the first dust collector and the boiler respectively, the separator receives the dust discharged by the first dust collector and separates the dust into large-size dust particles and small-size dust particles, the small-size dust particles are used to be input into the boiler

[0009] In some embodiments of the present application, the boiler fly ash recycling system also includes a balancing bin and a fan, the separator is connected to the boiler through the balancing bin, the balancing bin receives the small-size dust particles, and the balancing bin is connected to the fan so that the small-size dust particles are input into the boiler under the action of the fan.

[0010] In some embodiments of the present application, the balance tank is provided with a pressure relief port.

[0011] In some embodiments of the present application, the boiler fly ash recycling system further includes a second dust collector, and the second dust collector is connected to the pressure relief port.

[0012] In some embodiments of the present application, the second dust collector is a bag dust collector.

[0013] In some embodiments of the present application, the balancing tank is connected to the boiler via a pipeline, and a valve is provided on the pipeline.

[0014] In some embodiments of the present application, the separator is a cyclone separator.

[0015] In some embodiments of the present application, the cyclone separator is provided with a first inlet, a first outlet, and a second outlet, the first inlet is connected to the first dust collector, the first outlet is connected to the balance bin, and the first outlet is higher than the second outlet.

[0016] In some embodiments of the present application, the boiler fly ash recycling system further includes a smoke exhaust duct, and the first dust collector is further connected to the smoke exhaust duct to discharge the treated flue gas into the smoke exhaust duct.

[0017] In some embodiments of the present application, the boiler fly ash recycling system further includes an ash storage bin, which is connected to the separator to receive the large-size dust particles.

[0018] The technical solution of the present application processes the flue gas generated by the boiler through a first dust collector to obtain dust, and the treated flue gas is discharged into the atmosphere to prevent the flue gas from being re-input into the boiler. The separator separates the dust to obtain large-size dust particles and small-size dust particles, and the small-size dust particles are re-input into the boiler. The small-size dust particles have a large specific surface area, can better adsorb alkali metals in the boiler, and can be discharged from the boiler along with the flue gas generated by the boiler. Through the circulation of a large number of small-size dust particles, the slagging and contamination of the boiler wall are slowed down. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0020] Figure 1 Schematic diagram of a boiler fly ash recycling system in some embodiments.

[0021] Description of Figure Numbers:

[0022] Boiler 1000;

[0023] First dust collector 2000;

[0024] Separator 3000, first inlet 3100, first outlet 3200, second outlet 3300;

[0025] Balance chamber 4000, pressure relief port 4100, valve 4200;

[0026] Fan 5000;

[0027] Second dust collector 6000;

[0028] Ash storage bin 7000;

[0029] Smoke exhaust duct 8000.

[0030] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0032] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0033] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0034] In addition, in this application, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0035] In order to reduce slagging and contamination when the boiler 1000 burns pulverized coal, the present application proposes a boiler fly ash recycling system, see Figure 1 As shown, the boiler fly ash recycling system includes a boiler 1000 , a first dust collector 2000 , and a separator 3000 .

[0036] Boiler 1000 is an energy conversion device. When chemical energy is input into boiler 1000, boiler 1000 can output steam, high-temperature water, etc. with a certain amount of heat energy. Taking the steam boiler 1000 of thermal power generation as an example, coal is used as fuel, and the coal is burned in the form of coal powder. For example, coal is prepared into coal powder by a coal mill. A coal mill is a machine that crushes coal and grinds it into coal powder. The coal mill crushes coal blocks into coal powder by crushing, smashing and grinding. The prepared coal powder is input into boiler 1000 for combustion. Boiler 1000 is provided with a furnace, that is, a combustion chamber. Coal can burn in the furnace to generate a large amount of heat, thereby heating the water in the container, so that the water generates steam and is drawn out, so that the generator set can be driven to generate electricity.

[0037] The first dust collector 2000 is connected to the boiler 1000, and is used to receive the flue gas generated by the boiler 1000 and treat the flue gas. Flue gas is generated during the continuous combustion of coal powder in the furnace. Flue gas is a mixture of gas and dust. The composition of flue gas is extremely complex. The gas mainly includes sulfur dioxide, nitrogen, carbon monoxide, carbon dioxide, hydrocarbons and nitrogen oxides, etc., and the dust mainly includes ash, coal particles, oil droplets and high-temperature cracking products. The first dust collector 2000 is a mechanical device that can separate dust from flue gas. The flue gas generated by the boiler 1000 is input into the first dust collector 2000. The first dust collector 2000 works to separate the dust and gas in the flue gas. The treated flue gas is directly discharged into the atmosphere, or further treated and discharged into the atmosphere. The dust processed by the first dust collector 2000 will be input into the separator 3000. It can be seen that the main function of the first dust collector 2000 is to separate dust from flue gas, so there are many types of the first dust collector 2000 to choose from, such as an electrostatic precipitator, a bag dust collector, a dry dust collector, etc., which can be selected according to actual conditions.

[0038] It is understandable that the connection between the first dust collector 2000 and the boiler 1000 means that the first dust collector 2000 and the boiler 1000 can cooperate with each other to realize the introduction of flue gas into the first dust collector 2000. The first dust collector 2000 can be directly connected to the boiler 1000, or indirectly connected to the boiler 1000. For example, the first dust collector 2000 is directly connected to the boiler 1000 through a pipeline, or the first dust collector 2000 is connected to a fan 5000 through a pipeline, and the fan 5000 is further connected to the boiler 1000 through a pipeline. This is also regarded as the connection between the first dust collector 2000 and the boiler 1000. The connection between the various components below is also the same, and it will not be repeated.

[0039] The boiler fly ash recycling system is provided with a separator 3000, and the separator 3000 is connected to the first dust collector 2000 to receive the dust discharged by the first dust collector 2000. For example, the first dust collector 2000 has a dust bin, and the dust generated in the process of treating the flue gas by the first dust collector 2000 is stored in the dust bin. The dust bin is provided with a pump body, and the pump body can drive the dust to be input into the separator 3000, for example, through a pipeline. The dust particles generated by the combustion of pulverized coal have different sizes, some of which have a larger size and some of which have a smaller size. The separator 3000 processes the dust to separate the dust into large-size dust particles and small-size dust particles.

[0040] It can be understood that the dust discharged from the dust collector is called fly ash, the large-size dust particles processed and output by the separator 3000 are large-size fly ash, and the small-size dust particles are small-size fly ash. Small-size dust particles and large-size dust particles are relative, and most of the small-size dust particles have a smaller particle size than most of the large-size dust particles.

[0041] Since small-sized dust particles have a larger specific surface area, re-introducing these small-sized dust particles into the boiler 1000 can effectively adsorb alkali metals (such as sodium vapor). As the small-sized dust particles continue to be introduced into the boiler 1000 to adsorb alkali metals and are discharged from the boiler 1000 along with the flue gas, the alkali metal content in the boiler 1000 will be greatly reduced, thereby alleviating the slagging and contamination of the boiler 1000.

[0042] The boiler fly ash recycling system has an ash storage bin 7000, which is a cavity with a relatively large capacity. The ash storage bin 7000 is connected to the separator 3000 through a pipeline, and large-size dust particles can be transported to the ash storage bin 7000 for storage for further processing.

[0043] In the present application, the flue gas generated by the boiler 1000 is not immediately transported to the separator 3000 for treatment and the small-size dust particles are not input into the boiler 1000, but the dust is first processed by the first dust collector 2000 and then transported to the separator 3000 for treatment, so as to avoid the gas separated from the flue gas being re-input into the boiler 1000 and affecting the combustion of the pulverized coal in the boiler 1000. For example, by first setting the first dust collector 2000 to treat the flue gas generated by the boiler 1000, the treated gas is directly discharged into the atmosphere or further treated and discharged into the atmosphere, so that the small-size dust particles processed by the separator 3000 can be mixed with the atmosphere and re-input into the boiler 1000. If the flue gas generated by the boiler 1000 is directly input into the separator 3000 for treatment, the small-size dust particles output by the separator 3000 will be mixed with the gas in the flue gas, which has low oxygen content and contains other harmful substances, and re-input into the boiler 1000 will affect the combustion of the pulverized coal in the boiler 1000.

[0044] As can be seen from the above, the technical solution of the present application processes the flue gas generated by the boiler 1000 through the first dust collector 2000 to obtain dust, and the treated flue gas is discharged into the atmosphere to prevent the flue gas from being re-input into the boiler 1000 and affecting the combustion of pulverized coal in the boiler 1000. The separator 3000 separates the dust to obtain large-size dust particles and small-size dust particles, and the small-size dust particles are re-input into the boiler 1000. The small-size dust particles have a large specific surface area and can better adsorb alkali metals in the boiler 1000, and can be discharged from the boiler 1000 along with the flue gas generated by the boiler 1000. Through the circulation of a large number of small-size dust particles, the slagging and contamination of the boiler 1000 wall are slowed down.

[0045] like Figure 1 As shown, in some embodiments, the boiler fly ash recycling system also includes a balancing bin 4000 and a fan 5000, the balancing bin 4000 is connected to the separator 3000 to receive the small-size dust particles, the balancing bin 4000 is connected to the fan 5000 to receive the air output by the fan 5000, and the balancing bin 4000 is connected to the boiler 1000 so that the small-size dust particles are input into the boiler 1000 under the action of the fan 5000. Through the setting of the balancing bin 4000, the small-size dust particles can be better collected, thereby facilitating timely control of the small-size dust particles to be re-input into the boiler 1000 to realize fly ash circulation.

[0046] Specifically, the balancing bin 4000 is a cabin having a cavity for accommodating small-sized dust particles. For example, the balancing bin 4000 is connected to the separator 3000 through a pipeline. The small-sized dust particles separated by the separator 3000 are transported to the separator 3000 through a pipeline. The small-sized particles have a faster flow rate when transported through the pipeline. After entering the balancing bin 4000, the flow rate decreases and the particles gradually accumulate in the balancing bin 4000.

[0047] The fan 5000 is a fluid machine that relies on input mechanical energy to increase gas pressure and discharge gas. The fan 5000 inputs external air into the balancing chamber 4000, and the pressure in the balancing chamber 4000 increases. Since the air is continuously input into the balancing chamber 4000, the fluid generated by the fan 5000 causes the small-sized dust particles in the balancing chamber 4000 to be disturbed, and then mixed with the airflow. This mixed airflow flows toward the boiler 1000, thereby bringing the small-sized dust particles back into the boiler 1000. The fan 5000 draws in the external atmosphere, so that the mixed airflow maintains a high oxygen content and does not affect the coal powder in the boiler 1000.

[0048] The balancing chamber 4000 and the boiler 1000 may be connected via a pipeline, and the airflow generated by the fan 5000 drives the small-size dust particles into the pipeline, and then transports them into the boiler 1000. A valve 4200 may be provided on the pipeline, and the valve 4200 is an adjustable type, so that by adjusting the opening degree of the valve 4200, the amount of small-size dust particles input into the boiler 1000 can be adjusted, so as to better adapt to the working conditions of the boiler 1000.

[0049] It can be understood that when the fan 5000 inputs air into the balancing bin 4000, the pressure of the balancing bin 4000 will increase. In order to prevent the small-sized dust particles in the balancing bin 4000 from flowing back to the separator 3000 through the pipe, it is necessary to set an anti-backflow device on the pipe between the balancing bin 4000 and the separator 3000, such as setting staggered baffles, or reducing the diameter of the pipe connecting the balancing bin 4000 and the separator 3000.

[0050] By providing the balance bin 4000, small-sized dust particles can be better collected, so as to control the transportation of small-sized dust particles, adapt to different working conditions of the boiler 1000, and minimize slagging and contamination when the boiler 1000 is burning coal.

[0051] Continue to combine Figure 1 As shown, in some embodiments, the balancing bin 4000 is provided with a pressure relief port 4100 , so as to better achieve the accumulation of small-sized dust particles and their transport to the boiler 1000 , and further prevent the small-sized dust particles from flowing back to the separator 3000 .

[0052] Specifically, after the separator 3000 separates the small-sized dust particles, the small-sized dust particles need to be transported to the balancing bin 4000. The small-sized dust particles will move with the airflow during the transportation process. As the small-sized dust particles are transported to the balancing bin 4000, the pressure of the balancing bin 4000 will continue to increase. If the internal and external pressures of the balancing bin 4000 are not balanced, the continued input of the small-sized dust particles will be hindered. Therefore, by setting the pressure relief port 4100, the excessive pressure will leak out from the pressure relief port 4100, thereby maintaining the internal and external balance of the balancing bin 4000. In addition, since the fan 5000 needs to input air to the balancing bin 4000, when the fan 5000 inputs a large amount of air, the pressure in the balancing bin 4000 will increase. In this way, the small-sized dust particles are easily backflowed back to the separator 3000 with the airflow. The pressure relief port 4100 is set to avoid the backflow of small-sized dust particles.

[0053] Further, continue to combine Figure 1 As shown, in some embodiments, the boiler fly ash recycling system further includes a second dust collector 6000, and the second dust collector 6000 is disposed at the pressure relief port 4100, so as to prevent small-size dust particles from escaping from the pressure relief port 4100 into the atmosphere.

[0054] Specifically, as described above, the function of the pressure relief port 4100 is to maintain the internal and external pressures of the balancing bin 4000. If the pressure in the balancing bin 4000 is too high, small-sized dust particles will escape from the pressure relief port 4100 into the atmosphere with the action of the airflow, which is likely to cause pollution to the atmosphere. Therefore, by arranging the second dust collector 6000 at the pressure relief port 4100, the small-sized dust particles escaping from the pressure relief port 4100 will be captured by the second dust collector 6000, thus preventing the small-sized dust particles from escaping into the atmosphere, and at the same time ensuring the balance of the internal and external pressures of the balancing bin 4000. There are many types of the second dust collector 6000, such as an electrostatic precipitator, a dry dust collector, etc., which can be selected according to actual conditions. Preferably, a bag dust collector is used. The airflow escaping from the pressure relief port 4100 enters the bag dust collector from the inlet and is then purified. The purified air is discharged from the outlet of the bag dust collector. The small-sized dust particles are collected in the ash hopper of the bag dust collector. The discharge valve of the ash hopper can be opened to re-input it into the balancing bin 4000. The use of a bag dust collector can not only achieve the pressure balance of the balancing bin 4000, but also facilitate the re-collection of the escaped small-sized dust particles.

[0055] Continue to combine Figure 1 As shown, in some embodiments, the separator 3000 is a cyclone separator, which can efficiently separate large-size and small-size dust particles and conveniently output the two separately. Figure 1The cyclone separator has a first inlet 3100, a first outlet 3200 and a second outlet 3300 ( Figure 1 The first inlet 3100, the first outlet 3200 and the second outlet 3300 shown in the figure are only schematic and do not represent the actual positional relationship. The first inlet 3100 is connected to the first dust collector 2000 through a pipeline, the first outlet 3200 is connected to the balance bin 4000 through a pipeline, and the second outlet 3300 is connected to the ash storage bin 7000 through a pipeline. The first outlet 3200 is arranged higher than the second outlet 3300, which makes it more convenient to output small-size dust particles.

[0056] Continue to combine Figure 1 As shown, in some embodiments, the boiler fly ash recycling system further includes a smoke exhaust pipe 8000, and the smoke exhaust pipe 8000 is connected to the first dust collector 2000. The smoke exhaust pipe 8000 is cylindrical and is arranged vertically to the ground. The smoke is discharged into the smoke exhaust pipe 8000 after being dusted by the first dust collector 2000. Since the smoke exhaust pipe 8000 has a certain height, the diffusion of pollutants in the smoke can reduce the impact on the surrounding environment.

[0057] The working process of the boiler fly ash recycling system is as follows: coal powder is burned in the boiler 1000, and the combustion of coal powder produces flue gas, which is transported to the first dust collector 2000 for dust removal. The dust-removed flue gas is discharged into the smoke exhaust pipe 8000 and then discharged into the atmosphere. The first dust collector 2000 discharges dust and inputs it into the separator 3000. The separator 3000 works to separate the dust into large-size dust particles and small-size dust particles. The large-size dust particles are input into the ash storage bin 7000 for storage for further processing, and the small-size dust particles are input into the balance bin 4000 for storage. The fan 5000 introduces air into the balance bin 4000 to drive the small-size dust particles to be re-input into the boiler 1000 through the pipeline to realize fly ash circulation. The small-size dust particles input into the boiler 1000 have a large specific surface area, so they can adsorb alkali metals and are discharged from the boiler 1000 together with the flue gas, thereby reducing slagging and contamination when the boiler 1000 burns coal.

[0058] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made based on the concept of the present application and the contents of the present application description and drawings, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A boiler fly ash recycling system, characterized in that: include: boiler; a first dust collector, the first dust collector being connected to the boiler to process flue gas generated by the boiler; as well as A separator is connected to the first dust collector and the boiler respectively, the separator receives the dust discharged from the first dust collector and separates the dust into large-size dust particles and small-size dust particles, and the small-size dust particles are used to be input into the boiler.

2. The boiler fly ash recycling system according to claim 1, characterized in that: The boiler fly ash recycling system also includes a balancing bin and a fan. The separator is connected to the boiler via the balancing bin. The balancing bin receives the small-size dust particles. The balancing bin is connected to the fan so that the small-size dust particles are input into the boiler under the action of the fan.

3. The boiler fly ash recycling system according to claim 2, characterized in that: The balance tank is provided with a pressure relief port.

4. The boiler fly ash recycling system according to claim 3, characterized in that: The boiler fly ash recycling system further includes a second dust collector connected to the pressure relief port.

5. The boiler fly ash recycling system according to claim 4, characterized in that: The second dust collector is a bag dust collector.

6. The boiler fly ash recycling system according to claim 2, characterized in that: The balance tank is connected to the boiler through a pipeline, and a valve is provided on the pipeline.

7. The boiler fly ash recycling system according to claim 2, characterized in that: The separator is a cyclone separator.

8. The boiler fly ash recycling system according to claim 7, characterized in that: The cyclone separator is provided with a first inlet, a first outlet and a second outlet, the first inlet is connected to the first dust collector, the first outlet is connected to the balance bin, and the first outlet is higher than the second outlet.

9. The boiler fly ash recycling system according to claim 1, characterized in that: The boiler fly ash recycling system further includes a smoke exhaust duct, and the first dust collector is also connected to the smoke exhaust duct to discharge the treated smoke into the smoke exhaust duct.

10. The boiler fly ash recycling system according to claim 1, characterized in that: The boiler fly ash recycling system further includes an ash storage bin connected to the separator to receive the large-size dust particles.

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