CN2051324U - Liquid-cinder pulverised-coal cyclone combustion apparatus - Google Patents

Abstract

The utility model relates to a liquid-cinder cyclone combustion apparatus. The granularity of powdered coal is 170 to 200 meshes, three-time rotary jet stream air supply is adopted, and the proportion of air volume is (15-20): (60-75): (15-25). A combustion chamber forms a horizontal inclination angle of 15 to 45 DEG; the utility model is provided with a powdered coal nozzle, the combustion chamber, a turbulent stream ring, an adhering slag notch and a slag box. The proportion of the useful length of the combustion chamber to the inside diameter of the combustion chamber is 3 to 6; the flowing diameter of the turbulent stream ring to the inside diameter of the combustion chamber is 0.3 to 0.6; a housing of the combustion chamber is made of straight carbon steel, and the water-cooling adhering slag is used by the utility model. The slag catching rate of the liquid-cinder reaches above 99 %; the discharge amount of NO-[X] is 250 to 450 ppm. The utility model can be used for continuous heating furnaces for rolled steel, forging furnaces, rotary kilns and other industrial furnaces.

Description

Liquid-cinder pulverised-coal cyclone combustion apparatus

The invention belongs to the fuel burner of industrial furnace and boiler.

Liquid deslagging powdered coal cyclone burning device is developed by dry bottom furnace and grows up.From 40～fifties of this century, states such as the U.S., the Soviet Union, Czech, West Germany have begun the type approval test of horizontal cyclone stove, and the U.S. has a large amount of horizontal cyclone stoves to put into operation from 50～sixties.Shortcomings such as furnace wall slagging scorification, the combustion intensity that it overcomes dry bottom furnace is low, the imperfect combustion degree is big for improving its retention efficiency, have developed liquid deslagging cyclone burner.The shortcoming of this burner mainly is the existence of analysing the iron phenomenon, and some countries have little by little abandoned the design and the manufacturing of this burner.But since energy crisis occurring abroad, from the mid-1970s, many countries develop the replace oil with coal system one after another, restart the research to liquid deslagging cyclone burner.U.S. TRW Ltd. (US) One Space Park, Redondo Beach CA 90278 U.S.A. began to be devoted to the research of high efficiency liquid deslagging pulverized coalapparatus from 1976, through supercooled state and hot test and carry out half type approval test, obtain good result of the test, this burner is suitable for the boiler improvement of replace oil with coal, and this device air-flow rotary speed reaches 20～30 revolutions per seconds, its centrifugal acceleration far surpasses acceleration of gravity, fine coal is under the effect in this field of force, and coarse granule adhesion combustion, fine grained have bigger response area, be space combustion, combustion intensity is big.(thicker fine coal is then thrown to wall, burns under wall high temperature) promptly realized the space of fine coal and the double-combustion of wall in the combustion chamber, so fine coal has been finished combustion process in less space, its combustion intensity can reach (36～42) * 10 ⁶KJ/hm ³, ignition temperature reaches 1800 ℃, simultaneously, owing under the vortex effect of flame, make flame be full of the combustion chamber.Therefore, have high burning efficiency and high ash-retention efficiency, oligosaprobic important feature.

The energy resource structure of China is based on coal, and coal accounts for more than 70% of whole energy.The industrial coal mode mainly is stoker feed and pulverized coal friring at present, phosphorus content is in 8～15% scopes in the stoker feed mode slag, pulverized coal friring then lime-ash is all stayed in the stove or is drained in the atmosphere, both contaminated environment, also influence the steel billet heating quality, and delayed firing rate, although, still can not reach the environmental protection standard of national regulation by adorning the expensive dust arrester of a cover.Liquid deslagging powdered coal cyclone burning device is used for heater for rolling steel, 70～90% of ash content before flue gas enters burner hearth in the coal, gets rid of with the form of liquid slag, and flue gas contains a large amount of fuel gas compositions, enter the burning that burner hearth mainly is a gaseous fuel, can not need to install dust arrester.Use liquid deslagging cyclone burner at heater for rolling steel, owing to avoid lime-ash to enter in the stove, improved the heating quality of steel billet, steel plate, steel pipe base, eliminated the blemish of the steel that steel surface productive set lime-ash causes.Simultaneously, because the lime-ash thermal conductivity factor is about 2～4.2KJ/mhc, is the 1/40-1/90 of straight carbon steel thermal conductivity factor, as seen under the ability of same heat supply, adopting liquid deslagging cyclone burner will improve the firing rate and the thermal efficiency of steel billet, is the comparatively ideal burner of heater for rolling steel.At present, this device remains is analysing problems such as iron phenomenon, high temperature corrosion, progressively solves.

The subject matter that purpose of the present invention exists at liquid deslagging cyclone burner; in order to prevent to analyse iron; take to reduce the time of staying of melt cinder; few accumulated slag or the not measure of accumulated slag; the present invention will once be designed to have the certain level inclination angle with secondary combustion chamber in the cyclone burner of horizontal liquid deslagging; so that reduce the melt cinder time of staying, after melt cinder entered the slag case, the granulation of washing by water immediately lime-ash was collected.For preventing the high temperature corrosion water cooled furnace wall, adopt the bigger eddy flow of swirl strength, so that overcome near the reducing atmosphere the wall, the high temperature corrosion of appearance, attached with stable furnace lining at wall-cooling surface simultaneously, the protection water-cooling wall prevents high temperature corrosion effectively.The structure of this device design will improve efficiency of combustion, and phosphorus content is 0～0.04% in the slag, reduce the billet surface dust stratification and improve the efficiency of heating surface, avoid heating to cause steel billet surface defect, reduce environmental pollution.

Liquid deslagging powdered coal cyclone burning device of the present invention is seen accompanying drawing 1, comprises fine coal shower nozzle (1), combustion chamber (3), primary air nozzle (4), overfiren air port (5), tertiary air orifice (6), slag-drip opening.The fine coal shower nozzle is set up the ignition gap (2) of center sleeve, and outer tube is offered the inlet (4) of wind of tangential conveying and fine coal, and its swirl strength is S=1～2, and nozzle is circular circumferential weld shape; The combustion chamber has water-cooled dross furnace lining, and liner is 0.01～0.015 meter a refractory masses, and combustion chamber length and its diameter are than L/D=3～6, and its level inclination is 15～45 degree; From nozzle outlet beginning to calculate 0.6～0.85 place that is positioned at the combustion chamber length overall, the flow-disturbing ring (7) with centre bore is installed, slag-drip opening and slag case (8) are positioned at 0.01～0.02 meter of flow-disturbing ring downstream.A wind, secondary wind, the perforated area of tertiary air inlet is selected to determine by its air quantity and wind speed.Primary air velocity 10～15 mark meter per seconds, air quantity accounts for 15～20% of total blast volume, secondary wind speed 45～70 mark meter per seconds, air quantity accounts for 60～75%, tertiary air speed 45～70 mark meter per seconds, air quantity accounts for 15～25%.Burning capacity of the present invention be 200～1000 kilograms/time fine coal, its total air coefficient is 1.05～1.1, the air coefficient of main chamber is 0.7～0.9, to guarantee keeping its reducing atmosphere, help flowing slag, the flammable gas ingredients that is produced, then when running into tertiary air, carry out the stove internal combustion again, this be gas combustion actual be in the heater for rolling steel thorax, to carry out, help improving the steel billet efficiency of heating surface and improve billet quality.

Wind and pulverized coal mixture are by being installed on the fine coal nozzle of burner end, and the swirl strength of fine coal nozzle is S=1～2.Fine coal nozzle center is a circular tube, is fire hole.Secondary wind and tertiary air are all from the tangential perforate of sidewall of combustion chamber, and its direction of rotation is identical with the direction of rotation of a wind, and secondary wind speed, wind-warm syndrome are identical with tertiary air speed, wind-warm syndrome, and wind speed is 45～70 a meters/mark, and wind-warm syndrome is 180～350 ℃.Secondary air flow accounts for total blast volume 60～75%, and tertiary air quantity accounts for 15～25%.

The combustion chamber adopts ordinary carbon steel to make; chamber wall adopts water cooling; but 0.01～0.015 meter of its wall lining refractories; dependence freezes solidly on the ash bed of wall-cooling surface; to reduce the heat load intensity of water-cooling wall; play the effect of protection chamber wall; in the combustion process; because whirlwind action of centrifugal force, high-temperature ash stick to and form lime-ash solidification layer, solidification layer progressive additive on the lower wall-cooling surface of temperature; after reaching certain concreting thickness; ash bed temperature towards flame reaches the lime-ash fusion temperature, becomes liquid slag and separates, and the combustion chamber by horizontal tilt flows into the slag case gradually.Simultaneously, can prevent the high temperature corrosion phenomenon under the high temperature reduction condition behind the formation ash bed, guarantee the long-life of water-cooling wall.

It is 0.7～0.9 that coefficient of excess air is selected in combustion chamber of the present invention, keeps reducing atmosphere, is imperfect combustion, and containing the fuel gas composition in the flue gas is H ₂And CO, feed tertiary air at combustor exit, burner hearth inlet, in burner hearth, form gas fuel combustion.Adopt sectional combustion can guarantee that the in-furnace slag fusing point is lower, favourable liquid deslagging simultaneously, avoids the too high interior temperature of stove to form too high NO again _X, experiment showed, that working as air coefficient is 0.7,340 ℃ of air preheating temperatures, NO in the flue gas _XContent minimum, content are 250～450PPm.

Flow-disturbing ring of the present invention is seen accompanying drawing 2, calculate 0.6～0.85 place that is positioned at the combustion chamber length overall from the nozzle outlet, the flow-disturbing ring is installed, its shape is a ring bodies, opened round hole, center (9) circulation diameter d, it is outer to be air ring (10), internal diameter is d, external diameter is the combustion chamber inside diameter D, the outer ring width of air ring is δ, and it is a that gap (11) width is left in flow-disturbing ring lower end, ratio d/D=0.3～0.6 of the perfectly straight footpath d of flow-disturbing circulation and the inside diameter D of combustion chamber, ratio δ/D=0.2～0.5 of corresponding outer ring width δ and inside diameter D, ratio a/d=0.25～0.4 of gap width and inside diameter D.Adopt the flow-disturbing ring to replace the backflow spout of traditional cyclone furnace, backflow nozzle configuration complexity, life-span are low.The flow-disturbing ring structure is simple, is convenient to make, and is difficult for accumulated slag, and the life-span is long, 0.01～0.20 meter, flow-disturbing ring downstream.Slag-drip opening and dreg discharging box are installed, are established water spray melt cinder granulating device in the slag case, guarantee to reduce accumulated slag.Simultaneously, the more conventional horizontal cyclone burner of 15～45 degree level inclinations has melt cinder time of staying weak point in the combustion chamber, more promptly flows into the slag case, and the utmost point advantageously avoids chamber wall the iron phenomenon to occur analysing.

The present invention adopts fan mill and other type mill.Coal is milled to 180～200 order fine coal, with machinery or pneumatic conveying method fine coal is delivered to the fine coal nozzle, the combustion chamber is level inclination 30 degree, primary air flow accounts for 15% wind speed 15 mark meter per seconds, and its eddy flow temperature S=1.98 adopts the sparking mode of igniting to light wind and pulverized coal mixture, add auxiliary air at main chamber, its wind speed 52 mark meter per seconds, air quantity 60%, wind-warm syndrome is 250-350 ℃.The flow-disturbing ring is positioned at 0.64 place from the jet expansion length overall, flow-disturbing ring d/D=0.59, and δ/d=0.3, a/d=0.25, slag-drip opening are positioned at 0.02 meter in flow-disturbing ring downstream.After lighting fine coal, the temperature of combustion chamber is increased to the lime-ash fusion temperature by room temperature through half an hour, reaches 1400～1500 ℃, begins to occur melt cinder, and the fuel gas of tertiary air burning main chamber makes fire box temperature reach 1300～1500 ℃.The cooling wall water, available industry water, the most handy purifying waste water, hydraulic pressure is 0.2-0.4MPa, melt cinder drains into the slag case and becomes the solid slag of granulation with the water slug melt cinder, can make cement aggregate.

The present invention adopts measures such as the combustion chamber of level inclination and corresponding flow-disturbing ring, combustion intensity and combustion rate have been improved, latter Ke Da is more than 99%, carbon containing is 0～0.04% in the lime-ash, common mechanical adds the burner of fine coal, phosphorus content reaches 8～15% in the slag, and the explanation the present invention that compares improves combustion rate, and the energy utilization is better.Measure retention efficiencies such as employing flow-disturbing ring can reach 70～90%, significantly reduce the pollution of ash content to environment, thereby, can reduce expensive dust arrester, its expense accounts for builds about 60% of stove gross investment, is example to produce 200000 tons of small-sized continuous furnaces per year, if adopt the present invention, reduce about 50～800,000 yuan of investment.The present invention reduces the billet surface dust stratification, improves the steel billet efficiency of heating surface, reduces oxidization burning loss, improves billet quality, by after reducing 1%, 20 ten thousand ton of steel rolling mill of oxidational losses and adopting this technology, can increase production about 2000 tons of steel every year.

Adopt the multistage combustion mode of three air feeds.Burn under reducing atmosphere, slag melting is lower, helps the liquid deslagging, simultaneously, because the burning indoor temperature is low, then reduces NO in the flue gas _XContent, air preheating temperature is 340 ℃, air coefficient is 0.7, the NO in the flue gas _XContent has only 250～450PPm, has significantly reduced environmental pollution.

The present invention can be used for the steel rolling continuous-type furnace, rotary kiln, forge furnace, Industrial Boiler and other industrial furnace.

Claims (2)

1, a kind of liquid deslagging powdered coal cyclone burning device, comprise fine coal shower nozzle, combustion chamber, primary air nozzle, overfiren air port, tertiary air orifice, slag-drip opening, it is characterized in that the fine coal shower nozzle sets up the ignition gap of center sleeve, outer tube is offered the inlet that tangentially send wind and fine coal, and nozzle is that its swirling number of circumferential weld shape is S=1～2; The combustion chamber has water-cooled dross furnace lining, 0.01～0.015 meter refractory masses of liner, and combustion chamber length and its diameter ratio, L/D=3～6, its level inclination is 15～45 degree; Be positioned at combustion chamber length overall 0.6～0.85 place (from nozzle outlet mark), the flow-disturbing ring with centre bore is installed; Slag-drip opening is positioned at the 0.01～0.2m in flow-disturbing ring downstream; Wind, secondary wind, tertiary air perforated area are selected to determine by its corresponding air quantity and wind speed, primary air velocity 10～15 mark meter per seconds, air quantity accounts for 15～20%, secondary wind speed 45～70 mark meter per seconds, and air quantity accounts for 60～75%, tertiary air speed 45～70 mark meter per seconds, air quantity accounts for 15～25%.

2, according to the described cyclone burner of claim 1, it is characterized in that the flow-disturbing ring, opened round hole, center d, it is outer, and external diameter is D for the air ring internal diameter is d, and the outer ring width of air ring is δ, it is a that the gap width is left in flow-disturbing ring lower end, ratio d/D=0.3～0.6 of flow-disturbing ring internal diameter and external diameter, ratio δ/d=0.2～0.5 of wide and internal diameter, gap width and internal diameter are than a/d=0.25～0.4.

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