A kind of flue gas denitrification system being exclusively used in three-waste fluidized mix combustion furnace
Technical field
The utility model relates to denitrating system, especially a kind of reducing process flue gas denitrification system being exclusively used in three-waste fluidized mix combustion furnace.
Background technology
The nitrogen oxide pollution on the environment discharged in the fixed sources of energy system combustion of fossil fuels processes such as middle and small burn coal boiler becomes the hot topic of environmental protection already.NOx is a kind of main Air Pollutants, and NOx and hydrocarbon can cause photochemical pollution under high light effect, and the NOx be discharged in air is the main cause forming acid rain, serious harm ecological environment.
Three-waste fluidized mix combustion furnace is for combustion residue, chemical waste liquid that useless ash, waste gas, coal slime and environmental protection treatment difficulty are larger, produces a kind of three wastes (giving up) waste-heat recovery device of high potential steam more.
In air, the NOx of about 65% is produced by coal combustion, and the fuel of three-waste fluidized mix combustion furnace is mainly the waste slag produced in coal chemical industry enterprises production process, useless ash and waste gas, although the calorific value of solids mixing fuel is low, sulfur content is lower, but because it is burner hearth combustion temperature higher (usually at 950 ~ 1050 DEG C), therefore the NOx content in three wastes kiln gas composition is generally at 400-500 mg/Nm3, NOx content height 100-200mg/Nm3 in the pure coal-fired type boilers smoke components such as average specific recirculating fluidized bed, and intractability is large, current domestic three-waste fluidized mix combustion furnace (containing two steam stoves) waste-heat recovery device there is no supporting NOx and removes device, this technology has filled up the blank of three wastes stove industry denitration, along with improving further and the progressively raising of environmental requirement of national environmental protection policy, denitrating flue gas is imperative, force the environmental protection pressure of denitration will implement to it each enterprise, therefore, a kind of be specifically designed to three-waste fluidized mix combustion furnace or two steam stove gas denitrifying technologies enforcement and promote very necessary.
The volume of ordinary fluidized bed boiler SNCR denitration is in the past little, reducing agent can not mix in time uniformly with flue gas, and the burning gases time of staying is short, so denitration efficiency is lower, the revert system of SNCR on boiler has impact simultaneously, easily causes the blocking of boiler revert system; And three wastes stove denitration volume is large, have mixed combustion furnace, upper flue and combined dust remover, the burning gases time of staying is long, and reducing agent can mix fully for a long time with flue gas, and path length is so on boiler returning charge without impact, and denitration efficiency is higher more abundant.
Utility model content
The purpose of this utility model is to provide a kind of flue gas denitrification system being exclusively used in three-waste fluidized mix combustion furnace, easy and safe to operate, failure rate is low, all parameter on-line monitorings, and Realtime Alerts, can realize package unit start & shutdown through one key.
The utility model for achieving the above object, the technical scheme adopted is: a kind of flue gas denitrification system being exclusively used in three-waste fluidized mix combustion furnace, comprising: dilution water pot, security protection system, reducing agent storage tank, air reservoir, control system, metering mixed allocation unit, combined dust remover, three-waste fluidized mix combustion furnace and upper flue;
Diluted ammonia water pot, reducing agent storage tank and air reservoir are connected to the charging aperture of metering mixed allocation unit by pipeline and pump, security protection system is connected to control system, three-waste fluidized mix combustion furnace is connected by upper flue with combined dust remover, upper flue arranges at least two injection of reducing agent injection devices, metering mixed allocation unit is connected with injection of reducing agent injection device on upper flue by pipeline, and injection of reducing agent injection device comprises general fan nozzle type injection of reducing agent injection device and spirality solid conical nozzle type injection of reducing agent injection device.
Further, the long 2.5-3.0m of upper flue, during denitrating system work, flue gas flow rate is different according to boiler load state, generally at 20-35m/s, according to the content of nitrogen oxide actual in three-waste fluidized mix combustion furnace flue gas, upper flue side arranges fan nozzle type injection of reducing agent injection device longitudinal together, quantity is 4, uniform arrangement, forms horizontal mist wall together during work; Flue top arranges 4 spirality solid conical nozzle type injection of reducing agent injection devices, spirality solid conical nozzle interlaced arrangement, this kind of injection of reducing agent injection device multilevel hierarchy solid is arranged, ensure to form multiple tracks Water curtain wall at flue, ensure that reducing agent and flue gas fully mix and react rapidly in flue, mist after smoke outlet flue enters into three wastes stove combined dust remover and reacts completely further, reducing agent is long the 850-950 DEG C of temperature range time of staying, can ensure that reducing agent atomization more evenly rationally, reacts more thorough.
Described metering mixed allocation unit: comprise metering distributor box, reducing agent flow control valve, reducing agent flowmeter, dilution water flow adjustable valve, dilution water flow gauge, dilution reducing agent stop valve, compressed air pressure-reducing valve and spinner flowmeter etc., namely above structure routinely prior art can be assembled into metering mixed allocation unit, is used for accurate-metering to distribute mixing reducing agent, dilution water and air.
Described three-waste fluidized mix combustion furnace is the abbreviation of ammonia three-waste fluidized mix combustion furnace (patent No.: ZL01215849.6), mainly the combustion parts of the three wastes (gas making waste residue, useless ash, waste gas), after combined dust remover be dust removal part.
Described security protection system refers to have warning alarm function by the ammonia gas detector that prevention ammonia is revealed.When ammonia occurring and revealing, alarm signal can be sent to control system, process in time with alert.
Described combined dust remover is connected to a three-waste fluidized mix combustion furnace container below, its Main Function is that the flue gas above after three-waste fluidized mix combustion furnace hearth combustion enters combined dust remover through upper flue, flue dust separation is carried out in deduster inside, a large amount of dust granule is ash port centralized recovery below, avoid washing away waste heat boiler below, its three-waste fluidized mix combustion furnace body mainly and is above combined.
Injection of reducing agent injection device: comprise air cooled tube, atomizer and atomized air tube, with upper-part routinely technology be formed by connecting.Described general fan nozzle type reduction injection apparatus comprises air cooled tube, general fan nozzle and atomized air tube.Described spirality solid conical nozzle type reduction injection apparatus comprises air cooled tube, spirality solid conical nozzle and atomized air tube.General fan nozzle reduction injection apparatus and spirality solid conical nozzle reduction injection apparatus all belong to injection of reducing agent injection device, and just atomizer is different.
The utility model is a kind ofly specifically designed to the complete denitration technology device removing NOx in three-waste fluidized mix combustion furnace flue gas, belongs to the flue gases purification of environmental technology field.This technology is the denitration technology of high temperature section, selective, non-catalytic reduction; reducing agent is weak aqua ammonia or ammonia, the urea of 5% ~ 12%; by special atomization jetting device; the uniform rare reducing agent of atomization is sprayed in three-waste fluidized mix combustion furnace high temp. flue; rare reducing agent is under the hot conditions of 850 ~ 1000 DEG C; concurrent raw reduction reaction is fully contacted selectively with the NOx in flue gas; NOx is resolved into nontoxic, harmless N2 and steam; finally realize qualified discharge; effectively can avoid environmental pollution, better preserve the ecological environment.
The beneficial effects of the utility model are: through repeatedly on-the-spot contrast experiment, compared with regular circulation fluidized bed smoke denitrification apparatus, the escaping of ammonia rate is reduced to below 8ppm by 12ppm, and denitration efficiency is promoted to more than 80% by 60%, can meet the denitration needs of three wastes stove completely.The upper flue of denitration position between three-waste fluidized mix combustion furnace and combined dust remover, operating temperature is between 850-1000 DEG C; Injection of reducing agent injection device is combined rotary, as required adopt multilevel hierarchy solid arrange, position can flue side and top uniform; Injection of reducing agent injection device can form multiple tracks Water curtain wall at horizontal flue, and guarantee reducing agent fully mixes with flue gas; Three-waste fluidized mix combustion furnace volume is large, and the burning gases time of staying is long, and denitration is more abundant.Denitration is run continuously; three-waste fluidized mix combustion furnace engineering adopts SNCR (SNCR) technique flue gas denitrification system; the method of operation is run continuously, requires that this system has very high reliability and availability, can not cause shutting down because of the fault of this system.Whole system automaticity is high, easy and safe to operate, failure rate is low, all parameter on-line monitorings, and Realtime Alerts, can realize package unit start & shutdown through one key.
Accompanying drawing explanation
Fig. 1 is structural representation of the present utility model.
Fig. 2 is the top view of the utility model three-waste fluidized mix combustion furnace, upper flue and combined dust remover structure division.
Fig. 3 is the structural representation front view of the utility model upper flue.
Fig. 4 is the structural representation top view of the utility model upper flue.
Wherein, 1, dilution water pot, 2, security protection system, 3, reducing agent storage tank, 4, air reservoir, 5, control system, 6, metering mixed allocation unit, 7, combined dust remover, 8, three-waste fluidized mix combustion furnace, 9, upper flue, 10, injection of reducing agent injection device, 10-1, general fan nozzle type injection of reducing agent injection device, 10-2, spirality solid conical nozzle type injection of reducing agent injection device.
Detailed description of the invention
Below in conjunction with drawings and Examples, the utility model is further illustrated.
As illustrated in fig. 1 and 2, be exclusively used in a flue gas denitrification system for three-waste fluidized mix combustion furnace, comprise: dilution water pot 1, security protection system 2, reducing agent storage tank 3, air reservoir 4, control system 5, metering mixed allocation unit 6, combined dust remover 7, three-waste fluidized mix combustion furnace 8 and upper flue 9.
Dilution water pot 1, reducing agent storage tank 3 and air reservoir 4 are connected to the charging aperture of metering mixed allocation unit 6 by pipeline and pump, security protection system 2 is connected to control system 5, three-waste fluidized mix combustion furnace 8 is connected by upper flue with combined dust remover 7, upper flue 9 arranges injection of reducing agent injection device 10, metering mixed allocation unit 6 is connected to injection of reducing agent injection device 10 on upper flue 9 by pipeline, described control system is PLC control system, and the reducing agent of described reducing agent storage tank 3 li is ammoniacal liquor.Described injection of reducing agent injection device comprises general fan nozzle type injection of reducing agent injection device and spirality solid conical nozzle type injection of reducing agent injection device.
As shown in Figures 3 and 4, the long 2.5-3.0m of upper flue, during denitrating system work, flue gas flow rate is different according to boiler load state, generally at 20-35m/s, according to the content of nitrogen oxide actual in three wastes kiln gas, upper flue 9 side arranges together longitudinally general fan nozzle type injection of reducing agent injection device, quantity is 4, uniform arrangement, and during work, longitudinally general fan nozzle type injection of reducing agent injection device level spray forms horizontal mist wall together, flue top arranges 4 spirality solid conical nozzle type injection of reducing agent injection devices, spirality solid conical nozzle type injection of reducing agent injection device interlaced arrangement, during work, spirality solid conical nozzle type injection of reducing agent injection device sprays downwards, the arrangement of this kind of injection of reducing agent injection device, ensure that reducing agent and flue gas fully contact in flue mix and react rapidly, mist after smoke outlet flue enters into three wastes stove combined dust remover and reacts completely further, reducing agent is long the 850-950 DEG C of temperature range time of staying, can ensure that reducing agent atomization more evenly rationally, react more thorough.
Regular circulation fluidized-bed combustion boiler, because nitrogen oxides in effluent is generally at 300mg/NM
3below, in exhaust pass, generally arrange one group of longitudinal shower nozzle, denitration efficiency is about 50-60%, and the escaping of ammonia is often up to 12ppm, the basic denitration demand that can meet CFBB, because three-waste fluidized mix combustion furnace nitrogen oxides in effluent is generally at 400-500 mg/NM
3, regular circulation fluid bed SCNR denitrating technique cannot meet three wastes kiln gas denitration needs, therefore, a kind of gas denitrifying technology being specifically applied to three-waste mixed fired boiler, conventional injection head is adopted to combine with spirality solid conical nozzle mode, can guarantee that reducing agent mixes with flue gas more even, simultaneously in conjunction with three-waste fluidized mix combustion furnace architectural characteristic, after reducing agent fully mixes with flue gas, upper flue 9 to combined dust remover 7 outlet is the reaction compartment of reducing agent and nitrogen oxide, recovery time can ensure at more than 2S, there is the sufficient recovery time, the utilization rate of reducing agent can be improved to greatest extent, save reducing agent consumption and namely reduce the escaping of ammonia rate, through repeatedly on-the-spot contrast experiment, compared with regular circulation fluidized bed smoke denitrification apparatus, the escaping of ammonia rate is reduced to below 8ppm by 12ppm, denitration efficiency is promoted to more than 80% by 60%, the denitration needs of three wastes stove can be met completely.
Waste residue and useless ash are mixed and are joined part bituminous coal or anthracite foam enters bottom three-waste fluidized mix combustion furnace through coal handling system, air distribution plate is utilized to carry out air distribution combustion, waste gas in production enters mixed combustion furnace burning in burner hearth middle and upper part, high-temperature flue gas (850-1000 DEG C) after mixed combustion enters deduster by upper flue and carries out flue dust disengaging, combined rotary injection apparatus can form multiple tracks Water curtain wall at horizontal flue, ensures that object allows reducing agent fully mix with flue gas.Flue gas after denitration enters main heating surface and waste heat boiler, and go desulfurizer desulfurization after entering the further dedusting of electrostatic precipitator subsequently, the flue gas after up to standard is emptying through chimney.
The three-waste fluidized mix combustion furnace device about more than 250 that the current whole nation is being run overlaps, a few covering device is only had to be configured with SCR equipment for denitrifying flue gas at present, though denitrating flue gas needs can be met, but investment comparatively large (single cover denitrification apparatus investment about about 1,000 ten thousand yuan), and although conventional SNCR equipment for denitrifying flue gas is invested less on coal furnace, but denitration efficiency is low cannot meet denitration needs, therefore, a kind of reducing process gas denitrifying technology being exclusively used in three-waste fluidized mix combustion furnace arises at the historic moment, the demand of three-waste fluidized mix combustion furnace denitrating flue gas can be met, greatly can reduce denitrification investment, NOx in flue gas can be dropped to 100mg/Nm simultaneously
3below, after can meeting completely, the requirement of country to NOx emission standard, has had denitrification apparatus to make fume emission cleaner, has decreased environmental pollution, protect environment.
By reference to the accompanying drawings detailed description of the invention of the present utility model is described although above-mentioned; but the restriction not to the utility model protection domain; one of ordinary skill in the art should be understood that; on the basis of the technical solution of the utility model, those skilled in the art do not need to pay various amendment or distortion that creative work can make still within protection domain of the present utility model.