CN200968599Y

CN200968599Y - Low-polluting and self-prewarming powdered coal burner

Info

Publication number: CN200968599Y
Application number: CN200620134283.XU
Authority: CN
Inventors: 张宗旺
Original assignee: University of Science and Technology Beijing USTB
Current assignee: SHANXI LANTIAN ENVIRONMANTAL ENGINEERING Co Ltd
Priority date: 2006-11-07
Filing date: 2006-11-07
Publication date: 2007-10-31
Anticipated expiration: 2016-11-07

Abstract

A low-pollution self-preheating pulverized coal burner. It belongs to the field of energy utilization and is widely used in coal-fired industrial furnaces and environmentally friendly and efficient pulverized coal boilers. It consists of two main parts, a pulverized coal burner (12) and a pulverized coal pre-combustion chamber (9). Including central pipe for conveying pulverized coal (1), primary air main pipe (2), primary primary air pipe with cyclone (3), primary auxiliary air pipe with gas burner cyclone (4), secondary main air pipe Cyclone (5), secondary air channel (6), annular pulverized coal nozzle (7), secondary auxiliary air cyclone (8), secondary air main pipe (10), secondary main air guide cone ( 11). Structurally, the central pipe, the primary main air, the primary auxiliary air, the secondary main air and the secondary auxiliary air are coaxially arranged. The pulverized coal combustion process is graded and segmented combustion, which can not only ensure the efficient combustion of pulverized coal, but also effectively control the maximum temperature of the combustion process and reduce the amount of NOx generated. The burner has sufficient pulverized coal combustion, stable flame, and good adaptability to coal types; it can realize stable operation under low load; it is easy to control and low in operating costs.

Description

A kind of low pollution is from the preheating powdered coal burner

Technical field

The utility model belongs to field of energy utilization, particularly a kind of coal burner.

Background technology

The coal dust firing efficient of general industrial kiln coal burner, environment protecting etc. have bigger limitation; And be used for coal dust firing (device) device of station boiler, and need bigger space, can't adapt to the burner hearth situation of medium small boiler; Again because the rise of oil price and the restriction of gas supply condition, be that the general operating cost of boiler of fuel is higher with fuel oil and combustion gas, be irrational economically, and be subjected to the restriction of region.Coal has resource and price advantage widely in China, progressively ripe, the at home and abroad good effect and the advantage of burning and environment protection control aspect thereof on the station boiler of pulverized coal combustion, for the application of coal dust on Industrial Stoves and middle-size and small-size Industrial Boiler provides broad space, and the development coal burner that 26S Proteasome Structure and Function is reasonable, environment protecting is good also demonstrates its necessity and urgency day by day.

Summary of the invention

The purpose of this utility model be a kind of high burning efficiency of design, low NOx generating capacity, simple in structure, control is convenient, satisfy general industry kiln and the practical powdered coal burner that requires of middle-size and small-size Industrial Boiler.Also can many this kind burners be installed, to satisfy the requirement of large-sized boiler on same boiler by taking suitable arrangement.

A kind of low pollution mainly is made of coal dust burner 12 and 9 two parts of coal dust precombustion chamber from the preheating powdered coal burner, it is characterized in that coal dust burner and precombustion chamber coaxial arrangement, and is installed on the center of precombustion chamber head.

Coal dust burner 12 comprises pulverized coal conveying central tube 1, wind house steward 2, an air main 3 of band cyclone, the once auxilliary airduct 4 and the ring-type coal nozzle 7 of band coal gas burner cyclone, pulverized coal conveying central tube 1 and air main 3 coaxial nested arrangement.One time wind house steward 2 connects an air main 3 and once assists airduct 4, one time air main 3 inlets are equipped with cyclone, outlet is equipped with the ring-type coal nozzle, coal dust central tube 1 passes a wind house steward 2 and communicates with an air main before the ring-type coal nozzle, and one time wind is divided into a main air and once assists wind by cyclone.One time main air works the screw form of revolving into through cyclone, mixes with a main air of screw before the ring-type coal nozzle from coal, the gas mixture of central tube 1, sprays through coal nozzle.Coal nozzle is designed to the reducing circulus, is diminished gradually by air main direction diameter of the wind comes from, and its final centre bore area of section is 20～60% of an air main area of section, adapts to the steady combustion demand of different coals and ature of coal.The once auxilliary airduct of band coal gas burner cyclone and pulverized coal conveying central tube 1 axis in the same way, greater than the circumference equal intervals of an air main or be circumferential weld shape layout, this radius of a circle is 1.5～2 times an of air main.The once auxilliary airduct center of each band coal gas burner cyclone can feed combustion gas, and periphery is the once auxilliary wind passage of band swirl vane, and once auxilliary airduct 4 has the function of gas ignition.Can give coal dust primary combustion zone supplemental oxygen through swirl-flow devices by the auxilliary wind that auxilliary airduct 4 once comes out, also have the effect of stable pulverized coal flame, again the secondary main air played insulating effect simultaneously, guarantee the combustion gas mixing of the too early and precombustion chamber of secondary main air.Be the once quantity of auxilliary airduct 4 that circumference is equidistantly arranged, can adjust,, can suitably increase its quantity, to improve ignition intensity to the difficulty coal dust that catches fire according to the ignition character of the coal dust that uses.

Because a main air adopts the mode of screw, can be at the low oxygen area that forms certain volume and shape near the back segment flame of coal nozzle exit position, suppress the higher a large amount of generations that cause NOx of coal dust firing peak temperature, be beneficial to the reduction that has generated NOx simultaneously.And because the design feature of coal nozzle, make the small particle diameter coal dust in the enrichment of coal nozzle outer circumference, a main air that rotatablely moves, the auxilliary wind space of between coal nozzle and once auxilliary wind nozzle, causing a low pressure once, form the recirculation of air-flow at this place, high-temperature combustion gas is drawn back, improve the ignitability of coal dust, played the effect of stablizing pulverized coal flame.Once auxilliary wind can intercept the burning that the secondary main air participates in coal dust too early again preferably, realizes the fired state of classification, segmentation.

Coal dust precombustion chamber 9 is inside and outside nested double-decker, comprises secondary main air cyclone 5, secondary air channel 6, and secondary is assisted wind cyclone 8, secondary wind house steward 10, secondary main air guiding awl 11.The secondary wind of being come in by secondary wind house steward 10 is divided into secondary main air and the auxilliary wind of secondary by secondary air channel at the precombustion chamber port of export, the secondary main air is folded to the opposite end of precombustion chamber, enters precombustion chamber by secondary main air guiding awl 11 guiding behind secondary main air cyclone 5 eddy flows.The auxilliary wind cyclone 8 of secondary along the circumferential direction is circumferential weld on the precombustion chamber end wall arranges, the auxilliary wind of secondary acts on the high temperature gas flow of precombustion chamber ejection with 20 °～45 degree through the auxilliary wind cyclone 8 of secondary.

Secondary wind (account for total combustion air volume 70～80%) can absorb the heat of precombustion chamber housing, reaches the effect of preheating secondary combustion air and protection precombustion chamber metal shell.After the secondary main air enters precombustion chamber, travel forward in a spiral manner along the precombustion chamber inwall, constantly absorb the heat of precombustion chamber inwall and the radiant heat of high temperature gas flow, temperature constantly raises.This secondary main air through preheating meets, mixes with central gas stream on the front and back position of precombustion chamber outlet, participates in the second-time burning of coal dust; The auxilliary wind of secondary acts on the high temperature gas flow of precombustion chamber ejection, intervenes the interior oxygen supply state of high temperature gas flow and the combustion kinetics condition on uncombusted coal dust surface, accelerates the burning velocity of coal dust.

Owing to adopted above-mentioned burner structure and air feed, coal supply measure, the utlity model has following practical function:

(1). swirling motion and fractional combustion make coal dust firing more abundant, and flame is more stable;

(2). the existence of low oxygen area can effectively suppress the formation of NOx, and promotes the reduction produced NOx;

(3). high-temp waste gas is evenly distributed on the vertical cross-section in combustion chamber (as: boiler cavity), there is no furnace wall slagging scorification and high temperature corrosion phenomenon and takes place;

(4). good coal adaptive capacity is arranged;

(5). the coupling adjustment by primary air flow, secondary air flow and coal supply powder amount, can realize the stable operation under the underload;

(6). control is simple, and operating cost is cheap.

Description of drawings

Fig. 1 is the utility model structural representation;

Fig. 2 is a coal dust burner end view;

Fig. 3 is a coal dust precombustion chamber end view.

The 1st, the center coal chute, 2 is wind house stewards, the 3rd, and an air main of band cyclone, the 4th, the once auxilliary airduct of band coal gas burner cyclone, the 5th, secondary main air cyclone, the 6th, secondary air channel, the 7th, the ring-type coal nozzle, the 8th, secondary is assisted the wind cyclone, the 9th, preheating chamber, the 10th, secondary wind house steward, the 11st, secondary main air guiding awl, the 12nd, coal dust burner.

The specific embodiment

When the utility model is installed, central air hose 1 is connected the coal dust carrier pipe, and a wind house steward connects primary air fan or pressure air, and secondary air channel connects overfire air fan or pressure air, the coal dust precombustion chamber is inserted an end of horizontal industrial kiln or pulverized-coal fired boiler, and is fixed on the coal dust body of heater.

The utility model operation sequence is as follows: but at first open the combustion powder that accumulates in the clean combustion chamber of secondary wind.After about 30 seconds, open primary air fan or (during the working pressure air) and open the wind steam supply valve one time, open igniting burnt gas switch valve then, and light by ignitor; When the ignition flame temperature meets the requirements of boundary value, begin to give the coal supply of coal dust burner by central tube, implement the pulverized coal ignition operation.Lighted and when the burner front end forms the retention flame, cut off the igniting combustion gas at coal dust, burnt by coal dust oneself fully.In the process of coal combustion, can realize that coal dust fully burns and the control of useless flue gas oxygen gesture according to flow and ratio for wind of powder amount adjusting and secondary wind; Also can regulate the position of pulverized coal flame in addition,, realize the controlled burning of coal dust to adapt to the burning feature of different coals by the ratio of wind of adjustment and secondary wind.

The utility model because taked the spiral of the hierarchical segmented supply of combustion air, coal dust to move ahead, Secondary Air inhales The auxiliary wind of temperature, secondary of receiving the radiant heat of precombustion chamber body heat and high temperature gas flow and improving self is to coal powder second The controlling party of the intervention of uncombusted coal dust firing reacting dynamics condition and improvement, simple and flexible in the combustion zone Method, thereby have the significantly variation and few to the coal restriction of flameholding, low NOx, efficient, suitable load Characteristics, be widely used in general coal-fired industrial furnace and middle-size and small-size environment-friendly high-efficiency pulverized-coal fired boiler, also can simultaneously The mode that adopts many tablecloths to put satisfies the heat demand of large-sized boiler.

Claims

1. one kind low is polluted from the preheating powdered coal burner, it is characterized in that powdered coal burner is made of coal dust burner (12) and (9) two parts of coal dust precombustion chamber, coal dust burner and coal dust precombustion chamber coaxial arrangement, and be installed on the center of coal dust precombustion chamber head.

2. low pollution as claimed in claim 1 is characterized in that the coal dust burner from the preheating powdered coal burner

(12) comprise an air main (3) of pulverized coal conveying central tube (1), a wind house steward (2), band cyclone, the once auxilliary airduct (4) and the ring-type coal nozzle (7) of band coal gas burner cyclone; Pulverized coal conveying central tube (1) and the coaxial nested arrangement of an air main (3), a wind house steward (2) connects an air main (3) and once auxilliary airduct (4), an air main (3) inlet is equipped with cyclone, outlet is equipped with the ring-type coal nozzle, coal dust central tube (1) passes a wind house steward (2) and communicates with an air main before the ring-type coal nozzle, and one time wind is divided into a main air and once assists wind by cyclone.

3. low pollution as claimed in claim 1 is characterized in that from the preheating powdered coal burner coal dust precombustion chamber (9) is inside and outside nested double-decker, comprises secondary main air cyclone (5), secondary air channel (6), secondary is assisted wind cyclone (8), secondary wind house steward (10), secondary main air guiding awl (11); The secondary wind of being come in by secondary wind house steward (10) is divided into secondary main air and the auxilliary wind of secondary by secondary air channel at the precombustion chamber port of export, the secondary main air is folded to the opposite end of precombustion chamber, enters precombustion chamber by secondary main air guiding awl (11) guiding behind secondary main air cyclone (5) eddy flow.

4. low pollution as claimed in claim 1 or 2 is from the preheating powdered coal burner, it is characterized in that coal nozzle is designed to the reducing circulus, diminished gradually by air main direction diameter of the wind comes from, its final centre bore area of section is 20～60% of an air main area of section; The once auxilliary airduct of band coal gas burner cyclone

(4) with pulverized coal conveying central tube (1) axis in the same way, greater than the circumference equal intervals of an air main or be the circumferential weld shape and arrange, greater than the radius of a circle of an air main 1.5～2 times an of air main, once auxilliary airduct (4) center of each band coal gas burner cyclone can feed combustion gas, and periphery is the once auxilliary wind passage of band swirl vane.

As claim 1 or 3 described low pollutions from the preheating powdered coal burner, it is characterized in that the auxilliary wind cyclone (8) of secondary along the circumferential direction is circumferential weld and arranges on coal dust precombustion chamber (9) end wall, the auxilliary wind of secondary acts on the high temperature gas flow of coal dust precombustion chamber ejection with 20 °～45 degree through the auxilliary wind cyclone (8) of secondary.