CN108758658A - A kind of useless activated coke Incineration in CFB system - Google Patents

Abstract

The invention discloses a waste activated coke circulating fluidized bed incineration system, which comprises a circulating fluidized bed incineration device, a steam drum, a tail flue gas heat recovery device, a first heat exchanger, a desulfurization and dust removal device, and an activated coke adsorption device arranged in sequence. Tower, induced draft fan and second heat exchanger, the flue gas produced by the circulating fluidized bed incineration device passes through the tail flue gas heat recovery device, the first heat exchanger, desulfurization and dust removal device and activated coke adsorption tower in sequence, and then passes through the induced After being drawn by the fan, it is discharged into the atmosphere through the second heat exchanger and the chimney. The waste activated coke circulating fluidized bed incineration system provided by the present invention uses the heat generated by the waste activated coke combustion to perform thermoelectric production, thereby realizing the utilization of waste energy, and at the same time performing environmental protection treatment on the tail gas generated by the waste activated coke combustion to achieve pollution-free emissions. The follow-up treatment of spent active coke is solved.

Description

A waste activated coke circulating fluidized bed incineration system

technical field

The invention belongs to the field of energy technology, in particular to a waste activated coke circulating fluidized bed incineration system.

Background technique

Traditional water treatment technologies such as chemical methods, biological methods, oxidation methods, activated carbon adsorption methods, membrane methods, etc., due to the weaknesses of the technology itself, require large investment and relatively high treatment costs for deep sewage treatment, and the treatment cycle Also longer, therefore, businesses and society can not afford. Activated coke is a granular substance with dual properties of adsorbent and catalyst developed from high-volatile coal as the main raw material. It is a porous carbonaceous substance and is an activated carbon adsorbent that has not been fully carbonized or activated. Activated coke has the characteristics of activated carbon, but at the same time it overcomes the disadvantages of high price, low mechanical strength and easy crushing of activated carbon.

Activated coke has a strong pore structure and special functional groups, and has a strong adsorption capacity for harmful components such as suspended solids, inorganic and organic substances in sewage, and activated coke is cheaper than activated carbon. A number of domestic sewage treatment enterprises have adopted activated coke It is used for the purification of urban sewage, industrial wastewater, polluted river water and other water sources. The wastewater treated by activated coke can be used for reuse of reclaimed water, which can effectively alleviate the discharge of wastewater and the pollution of the environment.

Although activated coke has absolute advantages over traditional sewage treatment processes in sewage purification treatment, the follow-up treatment of waste activated coke (activated coke that loses its activity after sewage treatment) is a difficult problem. Although the regeneration treatment process of activated carbon can be used for reference (such as chemical regeneration method of chemical elution, biological regeneration method, wet oxidation method, electrolytic oxidation method or heating regeneration method) for active regeneration of waste activated coke, but due to the high water content of waste activated coke , the amount of adsorbed organic matter is large, and the regeneration activity treatment is not only costly and the number of times is limited, but also the adsorbed organic matter is easily precipitated from the pore structure of the spent activated coke, causing secondary pollution. If it is randomly stacked, it will inevitably cause environmental pollution. Therefore, It is urgent to solve the utilization problem of waste activated coke.

Contents of the invention

The purpose of the present invention is to provide a circulating fluidized bed incineration system for waste activated coke, which uses the heat released by the combustion of waste activated coke rich in water and organic matter to produce high-temperature and high-pressure steam, thereby carrying out power production or heat supply, and finally realizing waste energy. At the same time, the tail gas produced by the combustion of waste activated coke is treated in an environmentally friendly manner to achieve pollution-free emissions and solve the follow-up treatment of waste activated coke.

The present invention adopts following technical scheme:

A circulating fluidized bed incineration system for waste activated coke, including a circulating fluidized bed incineration device, a steam drum, a tail flue gas heat recovery device, a first heat exchanger, a desulfurization and dust removal device, an activated coke adsorption tower, and an induced draft fan arranged in sequence and a second heat exchanger.

The circulating fluidized bed incinerator includes a circulating fluidized bed incinerator, a feeder and an igniter connected to the bottom of the circulating fluidized bed incinerator, a separator connected to the top of the circulating fluidized bed incinerator, and a The feeder between the circulating fluidized bed incinerator.

A primary air duct is arranged in the igniter.

The separator is a cyclone separator.

The waste activated coke enters the circulating fluidized bed incinerator through the feeder, heats the circulating fluidized bed incinerator through the igniter, and sends it into the primary air through the primary air pipe. After the waste activated coke is burned, it is broken to produce ash particles, which are passed through After being separated by the separator, it returns to the circulating fluidized bed incinerator through the feeder or enters the tail flue gas heat recovery device.

The height of the circulating fluidized bed incinerator is 25 to 50 meters, mainly because the combustible volatile matter precipitated from the waste activated coke in the incinerator has sufficient residence time, and the residence time is 4-6 seconds, so that the combustion is more complete .

Several secondary air pipes are arranged on the opposite wall of the circulating fluidized bed incinerator, mainly for adjusting the combustion state; by injecting a certain amount of secondary air into the circulating fluidized bed incinerator, nitrogen can be effectively suppressed. The generation of oxides; the secondary air input by the secondary air pipe accounts for 40-60% of the total air volume in the circulating fluidized bed incinerator, and the percentage is volume ratio.

Preferably, the secondary air input by the secondary air pipe accounts for 50% of the total air volume in the circulating fluidized bed incinerator, so as to realize the full combustion of spent activated coke and suppress the generation of nitrogen oxides.

The inner wall of the circulating fluidized bed is arranged with a water-cooled wall, which mainly absorbs the heat released by the combustion of waste activated coke.

The combustion temperature in the circulating fluidized bed incinerator is 850-950°C.

The tail flue gas heat recovery device is arranged in sequence from top to bottom with a high-temperature superheater, a low-temperature superheater, an economizer and an air preheater.

The steam drum is divided into an upper part and a lower part, the upper part is connected with the outlet of the economizer, the outlet of the water wall and the low-temperature superheater, and the lower part is connected with the inlet of the water wall. The steam drum is mainly used for the separation of steam and water. The steam separated from the steam drum is connected to electric power or heating equipment through the low-temperature superheater and high-temperature superheater in turn, and is used for power production or heat supply.

The inlet of the economizer is connected with the water supply device, and the outlet is connected with the upper half of the steam drum.

The inlet of the air preheater is connected with the blower, and the outlet of the air preheater is connected with the primary air pipe and the secondary air pipe.

The waste activated coke circulating fluidized bed incineration system also includes a denitrification device arranged between the outlet of the circulating fluidized bed incinerator and the separator, and its main function is to remove nitrogen oxides generated during the combustion of waste activated coke.

The denitrification device is a selective non-catalytic reduction (SNCR) denitrification device. Under the action of no catalyst, a reducing agent is injected into the "temperature window" suitable for the denitrification reaction to reduce the nitrogen oxides in the flue gas to harmless of nitrogen and water.

The reducing agent in the selective non-catalytic reduction (SNCR) denitrification device is selected from ammonia water or urea.

The first heat exchanger is connected with the second heat exchanger, and after exchanging heat with the flue gas, the first heat exchanger lowers the flue gas to a certain temperature to facilitate the normal operation of the desulfurization and dust removal device. In addition, the first heat exchanger The cooling medium in the cooling medium absorbs the heat of the flue gas and transfers it to the second heat exchanger as a heating medium, which is used to heat the flue gas at the chimney inlet to increase the temperature of the exhausted flue gas and avoid problems such as flue gas blockage and low-temperature corrosion; the second The heating medium in the heat exchanger exchanges heat with the flue gas and is transferred to the first heat exchanger as a cooling medium.

The method for using the above waste activated coke circulating fluidized bed incineration system comprises the following steps:

(1) Add quartz sand in the circulating fluidized bed incinerator;

(2) Turn on the igniter to heat the quartz sand to 650-750°C and feed the primary air;

(3) The waste activated coke is transported to the circulating fluidized bed incinerator through the feeder for combustion, and the secondary air is introduced through the secondary air pipe during combustion; the heat released by the waste activated coke incineration in the circulating fluidized bed is partially consumed Water wall recycling;

(4) The flue gas from the circulating fluidized bed incinerator passes through the tail flue gas heat recovery device for heat recovery;

(5) The flue gas enters the first heat exchanger to cool down in turn, enters the desulfurization and dust removal device for desulfurization and dust removal, and then enters the active coke adsorption tower to remove organic matter;

(6) The flue gas enters the chimney after being heated by the induced draft fan and the second heat exchanger.

The quartz sand in the step (1) is mainly used as a heat carrier for heat transfer with the waste activated coke, the particle size is 0-5mm, and the height in the circulating fluidized bed furnace is 300-700mm; The effect of heat transfer.

In the step (2), the igniter is turned on to heat the quartz sand to 650-750°C, mainly because the ignition point of the waste activated coke semi-coke is relatively high, basically above 650°C.

The waste activated coke circulating fluidized bed incineration system provided by the present invention uses waste activated coke as a raw material, and through a reasonable air distribution ratio and the arrangement of environmental protection devices, can realize efficient combustion and pollution-free emission of waste activated coke. The high-temperature and high-pressure steam recovered by the tail recovery device can be used for heating or power production, which not only realizes the energy and clean utilization of waste activated coke, but also increases the income of the enterprise.

Description of drawings

Fig. 1 is the structural representation of the waste activated coke circulating fluidized bed incineration system provided by the present invention;

Among them, 1. Circulating fluidized bed incinerator; 2. Water wall; 3. Secondary air duct; 4. Feeder; 5. Igniter; (SNCR); 9. High temperature superheater; 10. Low temperature superheater; 11. Economizer; 12. Air preheater; 13. First heat exchanger; 14. Desulfurization and dust removal device; 15. Activated coke adsorption tower; 16. Induced fan; 17. Chimney; 18. Second heat exchanger; 19. Steam drum.

Detailed ways

The present invention will be further explained below in conjunction with specific examples.

As shown in Figure 1, a waste activated coke circulating fluidized bed incineration system includes a circulating fluidized bed incineration device, a steam drum 19, a denitrification device 8, a tail flue gas heat recovery device, and a first heat exchanger 13 arranged in sequence , desulfurization and dust removal device 14, activated coke adsorption tower 15, second heat exchanger 18 and induced draft fan 16, the flue gas produced by the circulating fluidized bed incineration device passes through the denitrification device 8, the tail flue gas heat recovery device, the first heat exchange device 13, desulfurization and dust removal device 14, and activated coke adsorption tower 15, and then is drawn by induced draft fan 16 and then discharged into the atmosphere through second heat exchanger 18 and chimney 17.

A circulating fluidized bed incinerator, including a circulating fluidized bed incinerator 1, a feeder 4 and an igniter 5 connected to the bottom of the circulating fluidized bed incinerator 1, and a cyclone separator connected to the top of the circulating fluidized bed incinerator 1 7 and the feeder 6 arranged between the cyclone separator 7 and the circulating fluidized bed incinerator 1; the outlet of the cyclone separator 7 is connected with the bottom of the circulating fluidized bed incinerator 1 through the feeder 6; the circulating fluidized bed The water-cooled wall 2 is arranged on the inner wall of the incinerator 1, and the secondary air pipe 3 is arranged on the opposite wall of the circulating fluidized bed incinerator 1; the tail flue gas heat recovery device is arranged in sequence from top to bottom with a high-temperature superheater 9 and a low-temperature superheater device 10, economizer 11 and air preheater 12; denitrification device (SNCR) 8, arranged between the outlet of circulating fluidized bed incinerator 1 and cyclone separator 7; the lower half of steam drum 19 and the water wall 2, the upper half of the steam drum 19 is connected to the outlet of the water wall 2, the outlet of the economizer 11, and the low-temperature superheater 10, and the water enters the steam drum 19 through the outlet of the economizer 11. The upper part, then enters the water wall 2 for water circulation; the inlet of the economizer 11 is connected to the water supply device; the inlet of the air preheater 12 is connected to the blower, and the outlet of the air preheater 12 is connected to the primary air pipe and the secondary air Pipe 3 is connected to provide heated primary air and secondary air.

Add a certain amount of quartz sand into the circulating fluidized bed incinerator 1, waste activated coke enters the circulating fluidized bed incinerator 1 through the feeder 4, turns on the igniter 5 to heat the quartz sand, and sends it into the primary air through the primary air duct. ; During the waste activated coke combustion process, the secondary air is injected into the circulating fluidized bed incinerator 1 through the secondary air pipe 3 to adjust the combustion conditions and effectively suppress the generation of nitrogen oxides; the water wall 2 absorbs the waste activated coke combustion released heat; the waste activated coke is burned and broken to produce flue gas, and the nitrogen oxides in the flue gas react with the reducing agent injected by the denitrification device 8 to generate nitrogen; the thicker part of the ash particles in the flue gas is separated by the cyclone separator 7 and passed through the return material The device 6 returns to the circulating fluidized bed incinerator 1, and the finer ash particles in the flue gas are removed in the desulfurization and dust removal device 14.

At the same time, the heat released by the combustion of chemical waste activated coke is sequentially recycled by the high-temperature superheater 9, low-temperature superheater 10, economizer 11, air preheater 12, and first heat exchanger 13; The pollutants such as SO ₂ and heavy metal Hg in the flue gas are removed in the desulfurization and dust removal device 14, and the undecomposed organic gases in the flue gas are adsorbed in the activated coke adsorption tower 15, so that the flue gas from the circulating fluidized bed incinerator 1 After being treated by the denitrification device (SNCR) 8, the desulfurization and dust removal device 14 and the activated coke adsorption tower 15, it becomes clean flue gas, which is drawn by the induced draft fan 16, heated by the second heat exchanger 18, and discharged into the atmosphere through the chimney 17 .

The first heat exchanger 13 communicates with the second heat exchanger 18, and the outlet of the first heat exchanger 13 communicates with the inlet of the second heat exchanger 18. After the first heat exchanger 13 exchanges heat with the flue gas, the The flue gas drops to a certain temperature, which facilitates the normal operation of the desulfurization and dust removal device 14. In addition, the cooling medium in the first heat exchanger 13 absorbs the heat of the flue gas and transfers it to the second heat exchanger 18 as a heating medium for heating the inlet of the chimney 17. flue gas to increase the exhaust gas temperature and avoid problems such as flue gas blockage and low-temperature corrosion; the heating medium in the second heat exchanger 18 exchanges heat with the flue gas and transfers it to the first heat exchanger 13 as a cooling medium.

The steam drum 19 is divided into an upper part and a lower part, the upper part is connected with the outlet of the economizer 11, the outlet of the water wall 2 and the low-temperature superheater 10, and the lower part is connected with the inlet of the water wall 2. The steam drum 19 is used for the separation of steam and water, and the separated steam is connected to the power equipment through the low-temperature superheater 10 and the high-temperature superheater 9 in sequence, and is used for power production; the separated water enters the water wall 2 again for water circulation to absorb part of waste activity The heat released by coke incineration in a circulating fluidized bed.

Application example 1

Table 1 shows the characteristic analysis data of typical chemical waste activated coke, which is incinerated with the waste activated coke circulating fluidized bed incineration system provided by the present invention.

Table 1 Characteristic analysis data of typical chemical waste activated coke

Add 40cm thick quartz sand into the circulating fluidized bed incinerator 1, send in 180Nm ³ /h primary air, turn on the igniter 5 to heat the quartz sand to about 650°C. The chemical waste activated coke fuel is fed into the circulating fluidized bed incinerator 1 through the feeder 4 and burned. During combustion, 180Nm ³ /h secondary air is introduced through the secondary air pipe 3, and the outlet temperature of the circulating fluidized bed incinerator 1 is maintained. At around 900°C.

The concentration of ash particles in the flue gas produced by the combustion of chemical waste activated coke is 11g/Nm ³ , which is 220mg/Nm ³ after being separated by the cyclone separator 7; at the same time, the combustion of chemical waste activated coke produces a large amount of pollutants, and the pollutant components in the flue gas The concentrations of nitrogen oxides (NO _x ), SO ₂ and dioxins are 140mg/Nm ³ , 326mg/Nm ³ and 0.062ng/Nm ³ respectively; the flue gas from the circulating fluidized bed incinerator 1 passes through the denitration device ( The concentration of nitrogen oxides (NO _x ) decreased to 40 mg/Nm ³ after SNCR) 8 was sprayed with ammonia water.

The flue gas from the circulating fluidized bed incinerator 1 (temperature is about 900°C) is cooled by the high temperature superheater 9 and the low temperature superheater 10, and then the temperature drops to about 450°C, and then it is absorbed by the economizer 11 and the air preheater 12 After heating, the temperature drops to about 150°C, and finally the temperature after heat exchange by the heat exchanger 13 is about 120°C, which is lower than the acid dew point temperature, which helps to improve the dust removal efficiency and desulfurization efficiency of the desulfurization and dust removal device 14 .

After the flue gas is removed by the desulfurization and dust removal device 14, the concentration of ash particles is only 4 mg/Nm ³ , the concentration of SO ₂ is reduced to 20 mg/Nm ³ , and the concentration of dioxin after being adsorbed by the activated coke adsorption tower 15 is about 0.0097 ng /Nm ³ or so.

The treated flue gas is clean flue gas, drawn by the induced draft fan 16, heated by the second heat exchanger 18 to 150°C, and then discharged into the atmosphere through the chimney 17.

The above application examples are only used to explain the inventive concept of the present invention, rather than to limit the protection of the rights of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments according to the essence of the technology and methods of the present invention are still valid. Belong to the technical and method scheme scope of the present invention.

Claims (8)

1. a kind of useless activated coke Incineration in CFB system, including the Incineration in CFB device, drum, the tail that are sequentially arranged Portion's fuel gas heat recycling device, First Heat Exchanger, desulfation dust-extraction device, activated coke adsorption tower, air-introduced machine and the second heat exchanger.

2. useless activated coke Incineration in CFB system as described in claim 1, which is characterized in that the recirculating fluidized bed Incinerator include circulating fluidized bed incinerator, the batcher being connect with circulating fluidized bed incinerator bottom and igniter, with follow The separator of circulation fluidized-bed incineration furnace roof portion connection and the material returning device being arranged between separator and circulating fluidized bed incinerator.

3. useless activated coke Incineration in CFB system as claimed in claim 2, which is characterized in that the recirculating fluidized bed The height of incinerator is 25~50 meters.

4. useless activated coke Incineration in CFB system as claimed in claim 2, which is characterized in that the recirculating fluidized bed Arrange that several secondary air channels, the Secondary Air of secondary air channel input account in circulating fluidized bed incinerator on the opposite wall of incinerator The 40-60% of total blast volume, the percentage are volume ratio.

5. useless activated coke Incineration in CFB system as claimed in claim 2, which is characterized in that the recirculating fluidized bed Ignition temperature in incinerator is 850~950 DEG C.

6. useless activated coke Incineration in CFB system as claimed in claim 2, which is characterized in that the useless activated coke is followed Ring fluidizing bed burning system further includes the denitrification apparatus being arranged between the outlet of circulating fluidized bed incinerator and separator.

7. useless activated coke Incineration in CFB system as described in claim 1, which is characterized in that the tail flue gas heat Amount retracting device is sequentially arranged high temperature superheater, low temperature superheater, economizer and air preheater from top to bottom.

8. useless activated coke Incineration in CFB system as described in claim 1, which is characterized in that the First Heat Exchanger It is connected with the second heat exchanger；It is transferred to the second heat exchanger conduct after the heat of cooling Absorption of Medium flue gas in First Heat Exchanger Heat medium；It is transferred to after heat medium and flue gas heat exchange in second heat exchanger in First Heat Exchanger as cooling medium.