CN101266043A

CN101266043A - Technological process suitable for fluidized-bed refuse incinerator system flue gas processing

Info

Publication number: CN101266043A
Application number: CNA2008101059524A
Authority: CN
Inventors: 盛宏至
Original assignee: Institute of Mechanics of CAS
Current assignee: Institute of Mechanics of CAS
Priority date: 2008-05-08
Filing date: 2008-05-08
Publication date: 2008-09-17
Anticipated expiration: 2028-05-08
Also published as: CN100554782C

Abstract

The invention discloses a gas processing technique suitable for a fluidized bed garbage furnace system. Gas produced from the garbage furnace is guided to a high temperature heat exchange surface so as to reduce the gas temperature to 450 DEG C-600 DEG C, thereby guiding the gas to a medium temperature separator with flying ashes in the gas settling by more than 80%; alkaline powder mass jets from a gas channel; the gas is further guided to a low temperature heat exchange surface to continue heat exchange; low temperature gas is subjected to a circulating fluidized bed dry humidification acid extracting tower to remove the acidic gas from the gas; the gas is guided to a low temperature electric field cottrell precipitator to separate alkaline powder mass; and the gas is guided to a bag-type dust remover to remove remanent granules. Through the technique, most flying ashes are separated in high temperature and medium temperature in a simple processing procedure. End gas below 500 DEG C is placed in alkaline protective atmosphere to inhibit resynthesis of dioxins. A first class low temperature electric field cottrell precipitator is added to realize the efficient separation of the posterior segment of the alkaline mass, so as to relieve the load of the bag-type dust remover.

Description

The process that a kind of suitable fluidized-bed refuse incinerator system flue gas is handled

Technical field

The present invention relates to smoke pollution control field, the technology that especially a kind of suitable fluidized-bed refuse incinerator system flue gas is handled.

Background technology

The modern city development can be made a lot of house refuses, generally will handle by sanitary landfills, During High-Temperature Composting, three kinds of methods of burning electricity generation, or utilize above-mentioned three kinds of method synthesis to handle.The burning electricity generation method is handled the method for domestic waste, not only effectively disposal of refuse, and can reclaim resources such as electric energy and heat energy, be density of population height, the soil first-selected waste disposal method in area in short supply.Existing advanced incinerator is fluidized bed refuse incinerator and circulating fluid bed garbage furnace, this incinerator adopts the fluidized combustion mode, has burning thoroughly, fuel tolerance is wide, thermal efficiency height, advantage such as harmful components are few in the flue gas is the clean incineration technology of generally acknowledging, but also caused the very big shortcoming of flying dust amount of discharging, thereby need carry out the subsequent treatment that flying dust reclaims.

The technology of grate furnace is continued to use in the smoke processing system technological process of fluid bed and recirculating fluidized bed (CFB) refuse burning system employing at present, be generally dry method or wet method depickling, add the sack cleaner dedusting, because flying dust only adopts sack cleaner to remove after the recuperation of heat utilization, not only deduster load flying dust amount very heavy, that collect is very big, and be deposited in a large number on the prime heat-transfer surface easily, cause problems such as heat exchange efficiency is low.And, if its flying dust according to national current standard requirement, is carried out the method for disposal of hazardous waste, carry out sending the security landfill field to dispose after stabilization is handled, with the cost of needs thousands of units per ton, so just bring great financial burden and cause the significant wastage of social resources.

In addition, usually handle the refuse that contains organochlorine and inorganic chlorine in the waste incineration, flue gas often contains more chlorinated organics that does not thoroughly decompose and hydrogen chloride etc.Reclaim heat energy being lower than under 500 ℃ the temperature, usually because the time of staying is longer, chlorinated organics or inorganic chlorine under the catalysis of heavy metal such as copper, iron, close into the dioxin harmful components again in flying dust.Therefore, at small incinerator, in medical destructor system, require below 500 ℃ temperature, to adopt the mode of water spray chilling to handle flue gas, to prevent the synthetic again of dioxin.But this method absorbs finite energy, and cooling-down effect is poor, and too much energy is finally wasted, and this wasting phenomenon is particularly remarkable to large-scale burning electricity generation factory.In order to control the content of flue gas Zhong dioxin, adopt the method control dioxin that in flue, sprays active carbon powder absorption usually, but the collection of active carbon powder and disposal are one of difficult problems in the existing technology in the large-scale incinerator.

Summary of the invention

At the problem that prior art exists, the object of the present invention is to provide a kind of process that can effectively handle flying dust and suppress the synthetic more suitable fluidized-bed refuse incinerator system flue gas processing of dioxin harmful components.

For achieving the above object, the process that a kind of suitable fluidized-bed refuse incinerator system flue gas of the present invention is handled is specially:

1) the flue gas guiding high temperature heat-transfer surface that incinerator is produced makes flue-gas temperature drop to 450 ℃～600 ℃, and then flue gas is imported warm separator in, makes flying dust granularity in the flue gas greater than 25 microns particle separation;

2) in flue, spray the alkaline powder material, synthetic again with the harmful components that suppress dioxin;

3) the low-temperature heat exchange face that further flue gas led continues heat exchange, reclaims heat energy;

4) low-temperature flue gas removes acidic gas in flue gas by circulating fluidized bed dry humidification extracting tower;

5) flue gas is imported low temperature one electric field electrostatic precipitator, separate the alkaline powder material that is added;

6) flue gas is imported sack cleaner at last and remove remaining particle.

Further, described in the operating temperature range of warm separator be 500 ℃～550 ℃, the mode that adopts multi-cyclone formula separator and middle temperature electrostatic precipitator to make up.

Further, the alkaline powder material is a calcium oxide CaO powder, and this CaO powder size is less than 80 orders.

Further, the operating temperature of described low temperature one electric field electrostatic precipitator is 160 ℃～220 ℃.

The present invention is directed to the characteristics of fluidized bed incinerator and recirculating fluidized bed (CFB) incinerator, in conventional garbage incineration flue gas processing technological flow, in 450～600 ℃ of temperature ranges, increase high efficiency in warm separator reduce flying dust amount in the flue gas significantly; Because most of flying dust that circulating fluidized bed incinerator is discharged separates with middle-temperature section at high temperature, do not belong to the flying dust that sack cleaner is collected, do not need expensive processing procedure just can dispose or utilization again.It is synthetic again to place alkaline protective atmosphere to suppress the dioxin harmful components in the tail gas below 500 ℃, and a flying dust of collecting with level after an action of the bowels can rationally utilize; The back segment that increased a grade low-temp one electric field electrostatic precipitator realization alkaline matter before sack cleaner effectively separates, and alleviates the load of sack cleaner.

Description of drawings

Accompanying drawing is a process method flow chart of the present invention.

The specific embodiment

Process method flow chart as shown in drawings, to burn in rubbish fluidized bed incinerator or the circulating fluidized bed incinerator, the high temperature heat-transfer surface rationally is set, make the flue-gas temperature after the heat exchange for the first time drop to 500 ℃～550 ℃, and then with warm separator in the flue gas importing one, because flue-gas temperature reduces, the gas viscosity descends, adopt the multicyclone deduster with in the middle temperature separator of gentle and quiet electric cleaner compound mode, the granularity that accounts for 80% above mass fraction in the flue gas coarse granule greater than 25 microns can be separated, thereby can make deduster porch flying dust amount drop to below 20% of original content, and the selection of this temperature can guarantee to utilize to greatest extent high-temperature flue gas, temperature is not higher than 600 ℃ under the high load capacity, and can prevent that temperature is lower than 450 ℃ under the running on the lower load.In adopt in the warm separator in the operating voltage of gentle and quiet electric cleaner be 3000 volts, operating current 2mA/m ²The electrode of electrostatic precipitator adopts the special alloy material to make, and is easy to issue radio in low-voltage, can also prevent the electric breakdown phenomena under the higher temperature.This electrostatic precipitator can with the integrated design in parallel of multicyclone, become cyclone electrostatic precipitator, also can be behind multi-tube dust cleaner independent the installation forms tandem and arranges.The flue-gas temperature that therefrom warm separator comes out is between 480 ℃～530 ℃; throw in granularity this moment in flue be 200 purpose calcium oxide CaO powder; thereby flue gas is placed alkaline protective atmosphere; suppress the synthetic again of dioxin effectively, be lower than 0.1ng-TEQ/Nm thereby satisfy dioxin content ³Discharge standard.After adding alkaline matter, flue gas imports the further heat exchange of low-temperature heat exchange face, and high efficiente callback heat energy adopts circulating fluidized bed dry humidification extracting tower to remove sour gas such as hydrogen chloride in the flue gas, hydrogen fluoride and sulfur dioxide subsequently.The depickling flue gas carries out back segment by low temperature one electric field electrostatic precipitator to the calcium oxide CaO powder of above-mentioned adding to be separated, its operating temperature is 160 ℃～220 ℃, and low temperature one electric field electrostatic precipitator can further adsorb 60% with remaining flying dust in the flue gas again, to alleviate the load of sack cleaner, guarantee the validity of sack cleaner work.Reducing the higher low temperature flying dust amount of bioxin and content of beary metal significantly simultaneously, also reduced chlorinity in the low temperature flying dust, help the utilization again of flying dust.Last flue gas imports sack cleaner and removes remaining particle, reaches discharge standard.

Because most flying dusts separate with middle-temperature section at high temperature, do not need the expensive processing procedure just can landfill or utilization again, reduced the flying dust disposal cost significantly.Remaining fine grained flying dust has bigger surface area, adsorb certain De dioxin and heavy metal class material, bigger toxic action is arranged, because total amount is less than 10% of original discharging, can carry out stabilization by high-temperature melting method and dispose, reach strict environmental requirement.

Claims

1, a kind of process of suitable fluidized-bed refuse incinerator system flue gas processing is specially:

6) flue gas is imported sack cleaner at last and remove remaining particle.

2, the process of suitable fluidized-bed refuse incinerator system flue gas processing as claimed in claim 1, it is characterized in that, the operating temperature range of warm separator is 500 ℃～550 ℃ in described, adopt multi-cyclone formula separator with in the compound mode of gentle and quiet electric cleaner.

3, the process of suitable fluidized-bed refuse incinerator system flue gas processing as claimed in claim 1 is characterized in that the alkaline powder material is a calcium oxide CaO powder, and this CaO powder size is less than 80 orders.

4, the process of suitable fluidized-bed refuse incinerator system flue gas processing as claimed in claim 1 is characterized in that the operating temperature of described low temperature one electric field electrostatic precipitator is 160 ℃～220 ℃.