CN2198512Y

CN2198512Y - High concentration coal powder burner

Info

Publication number: CN2198512Y
Application number: CN 94224470
Authority: CN
Inventors: 童玉清
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-07-27
Filing date: 1994-07-27
Publication date: 1995-05-24
Anticipated expiration: 2004-07-27

Abstract

The utility model relates to a novel high concentration coal powder burner, belonging to the technical field of coal dust firing. The combustion equipment is composed of low pressure dense phase conveying equipment with small energy consumption and without noise-a dense phase conveying slot and a coal burner. The dense phase conveying slot is a skewed slot with a constant slope, and the skewed slot is a sealing cabinet with a ventilation interlayer in the center. The coal burner is an ordinary burner or a preheating shape burner. The conveying slot and the burner are connected through an air powder mixer whose other end is led into primary air. The utility model has the advantages of simple structure, low energy consumption, and low noise.

Description

High concentration coal powder burner

The utility model relates to a kind of new coal powder burner apparatus, belongs to coal powder burning technology field.

In order to improve the coal dust firing effect, raise the efficiency, reduce NO _xPollution to atmosphere has developed " pulverized coal bias combustion " technology in recent years both at home and abroad.This technology is to have added a separator on the coal dust pipeline of original circulation low concentration, and the pulverized coal flow that makes low concentration is by this device the time, and a part of enrichment becomes one high concentration pulverized coal stream (dense); Another part then is that one powder containing quantity is few, air accounts for the very low pulverized coal flow of most concentration (light).After the separation one dense one light two strands of pulverized coal flows are sent to combustion chambers burn.One its combustion characteristics that concentration is high can greatly be improved, and under the drive of this strand high concentrated coal powder, light powder stream also is being with to burn.

Though the used structure of this class technology is not quite similar, this strand high concentration pulverized coal stream has good combustion characteristics, is confirmed by a large amount of experiments.But the shortcoming of this class technology is: the differential pressure restriction that 1. will be subjected to former once air pipe line structure usually and flow, and transform and get up to have certain degree of difficulty; 2. dense, light two strands going on the mode of combustion chamber and on the layout of burner, limiting because of being subjected to original structure, certain difficulty is arranged.In addition, after two strands of coal dusts spray into the combustion chamber, do not do a good job to mix again easily and reduce concentration, impact effect; 3. its concentration strictness of high concentration pulverized coal is not dense more good more in fact, in fact has optium concentration, and its value is different because of coal.Above-mentioned technology generally can't be regulated the concentration after separating, so be difficult for realizing the best combustion operating mode; 4. there is wear problem in mechanical separation device.

For this reason, develop the high concentration pulverized coal combustion technology in the world, on " the electric comment in east " (the rolling up the 203rd page of 6 the 4th phase) of publishing in December, 1992, disclose the example that the former Soviet Union uses.It is said that this technology successfully is applied on 200,000,300,000,500,000 and 800,000 kilowatts of unit boilers of anthracite, brown coal and bituminous coal.This technology is to use independently wind regime (compressed air, positive pressure system) or other medium (steam injection, negative pressure system), the very high coal dust of density (Gu-gas than C/A=55Kg/Kg) via very thin pipeline, be sent to burner with close phase carrying method, make it again to converge, be mixed into best high concentration pulverized coal stream and spray into combustion chambers burn with a wind.Technology is successful, mainly contains two advantages: 1. broken away from the conventional method restriction to coal powder density of wind, C/A=0.3～0.7Kg/Kg is achieved the high concentrated coal powder combustion technology; In addition, can directly regulate coal powder density and reach optimum value, obviously shorten ignition time, strengthen surely combustion.2. hindered NO effectively _xGeneration, reduced NO _xDischarging has realized clean burning.Its shortcoming is: 1. the method energy consumption of these two kinds of close phase pulverized coal conveyings is big, equipment investment is big; 2. noise is big, and the noise pollution problem is arranged.

The purpose of this utility model is a kind of novel high concentration pulverized coal combustion device of design, the structure of simplification device, and cut down the consumption of energy and noise.

Content of the present utility model is: the high concentration pulverized coal combustion device comprises airduct, air and powder mixer, close phase delivery chute and adjustable preheating burner one time.Close phase delivery chute has one 4～5% gradient in the flute length direction, and cell body is a sealing secret room, and there is a ventilative interlayer centre, and cell body is divided into upper and lower two parts.Adjustable preheating burner is a preheating tube, and the top of tube is connected with the control airduct, the diameter D of preheating tube _YWith a dust diameter d ₀The pass be: D _Y=(1.75～2.50) d ₀, the length L of preheating tube _YWith diameter D _YThe pass be: L _Y=(1.10～2.0) D _YThree ports of air and powder mixer communicate with the first half of close delivery chute mutually, airduct and preheating burner respectively.

Description of drawings:

Fig. 1 is the high concentration pulverized coal combustion apparatus structure schematic diagram with adjustable preheating burner.

Fig. 2 is the burner structural representation of band ordinary burner.

Fig. 3 is the A-A cutaway view of Fig. 1 and Fig. 2.

Fig. 4 is that the B of Fig. 1 is to view.

Below in conjunction with accompanying drawing, introduce content of the present utility model in detail.Among Fig. 1 to Fig. 4, the 1st, Pulverized Coal Bin, the 2nd, machine supplying powder, the 3rd, the close skewed slot of carrying mutually, the 4th, carry wind, 5 is airducts, 6 is a wind, be pure air, the 7th, air and powder mixer, the 8th, ordinary burner, the 9th, adjustable preheat burner, the 10th, control wind, the 11st, carry the ventilation interlayer in the skewed slot, its material is the powder metallurgy filter.D _YBe preheating tube diameter, d ₀Be a dust diameter, L _YIt is preheating tube axial length.

Coal dust in the Pulverized Coal Bin 1 is sent into the interlayer top of close phase delivery chute 3 by machine supplying powder 2 controls, carries wind 4 to send into the below of carrying skewed slot 3, and wind-force holds up the coal dust above the interlayer through interlayer and forms air cushion layer.Air cushion layer makes frictional resistance become minimum, so coal dust is slided to lower by height under the gravity effect, is sent to air and powder mixer 7 always.A wind (pure air) 6 also is sent to from burner not far air and powder mixer 7 and coal dust from an airduct 5 and meets, and it is broken up acceleration, makes it equably from burner 8 or 9 ejections.The 10th, one controls wind, by can control the degree of preheating to its adjustment, make different coals, ature of coal can both be after ejection the steady combustion of in time catching fire of certain distance.

The close defeated mutually powder equipment of the utility model design has advantages such as energy consumption is low, noiselessness.Coal dust enters through machine supplying powder on the interlayer of the higher end of delivery chute, feeds the conveying wind of pressure head～450mm water column under the interlayer.The coal dust layer can be held up slightly when carrying wind to see through interlayer, make and form the skim mattress between coal dust layer and the ventilative interlayer, thereby make and have frictional resistance between coal dust layer and the interlayer hardly, the coal dust layer can be under the effect of gravity thus, along the route of conduit regulation by height to low, slide with the speed of 1～2 meter per second.C/A was very big when this mode was carried, and can reach 40～60Kg/Kg, and is bigger 100 times than conventional method, so delivery chute appearance and size is very little.Since coal dust sliding speed low (1～2 meter per second), thus little to the cell wall wearing and tearing, carry the blast head low again, so can make of thin-walled material.Because carry out close conveying mutually with the design, manufactured materials takes province, freight is low, and seldom needs maintaining.The amount of feeding of coal dust is controlled by machine supplying powder, and coal dust is promptly transported to from the not far air and powder mixer of burner by conduit.

Thus, one time airduct is then only walked pure air, meets in air and powder mixer place ability and coal facies, at this moment just relies on the wind-force of a wind that coal dust is broken up, mixed, and is made into high concentration pulverized coal then.Because the high concentration pulverized coal primary air ratio is very low, institute's required airflow is very little, so caliber can be less; Again because of no longer containing powder in the wind, so resistance greatly reduces; One time wind does not contain powder, and there is not wear problem in tube wall, and therefore an airduct can adopt light-wall pipe, has saved material.

The utility model has designed two types of burners as required, forms a novel high density burner with top conveying device.

1. plain edition burner: this be for ature of coal better, the constant substantially occasion of coal uses.

2. adjustable preheating burner: this aims at that ature of coal is relatively poor, coal is changeable and to the inconvenient occasion design of underload.Its characteristics are to special unburnable coal, when the low anthracite of split pole that for example volatilizees, general high concentration pulverized coal combustion device still can't guarantee in time to catch fire steady the combustion, primary wind and powder is added strong pre-heating improve initial temperature.Therefore designed preheating type high concentration pulverized coal combustion device.Its structure as shown in Figure 1 and Figure 4.At diameter is d ₀An airduct in, when medium sprays from preheating burner with certain speed, can form certain negative pressure in the preheating tube, under the effect of this negative pressure, the hot flue gas of combustion chamber can be sucked into, therefore can heat the coal dust in the wind.Because coal might change, preheat requirements is had nothing in common with each other, so the utility model burner design form of becoming can regulate the preheating degree, preheat temperature can reach about 700 ℃.Through the primary wind and powder of appropriate preheating, volatile matter can be separated out fast, and flame propagation velocity is accelerated, so can obviously shorten ignition time, strengthens steady combustion effect, guarantees that various coals in time catch fire spraying about 250 millimeters.Its low-load combustion-stabilizing effect is very outstanding.

Claims

1, a kind of high concentration pulverized coal combustion device comprises airduct, air and powder mixer, it is characterized in that also comprising close phase delivery chute and adjustable preheating burner; Described close phase delivery chute has one 4～5% gradient in the flute length direction, and cell body is a sealing secret room, and there is a ventilative interlayer centre, and cell body is divided into upper and lower two parts; Described adjustable preheating burner is a preheating tube, and the top of tube is connected with the control airduct, the diameter D of preheating tube _YWith a dust diameter d ₀The pass be: D _Y=(1.75～2.50) d ₀, the length L of preheating tube _YWith diameter D _YThe pass be: L _Y=(1.10～2.0) D _YThree ports of described air and powder mixer communicate with the first half of close delivery chute mutually, airduct and preheating burner respectively.

2, a kind of high concentration pulverized coal combustion device comprises airduct, air and powder mixer, burner, it is characterized in that also comprising close phase delivery chute; Described close phase delivery chute has one 4～5% gradient in the flute length direction, and cell body is a sealing secret room, and there is a ventilative interlayer centre, and cell body is divided into upper and lower two parts; Three ports of described air and powder mixer communicate with the first half of close delivery chute mutually, airduct and burner respectively.