CN1109844C

CN1109844C - Coal gasifying burner

Info

Publication number: CN1109844C
Application number: CN 95112452
Authority: CN
Inventors: 王立; 云庆祯; 戴方钦; 杨彰佳
Original assignee: WUHAN INST OF METALLURGICAL BUILDING MINISTRY OF METALLURGICAL INDUSTRY
Current assignee: WUHAN INST OF METALLURGICAL BUILDING MINISTRY OF METALLURGICAL INDUSTRY
Priority date: 1995-09-14
Filing date: 1995-09-14
Publication date: 2003-05-28
Anticipated expiration: 2015-09-14
Also published as: CN1126810A

Abstract

The present invention discloses a coal powder gasifying and combusting device which belongs to a heating device and is suitable for heat supply to high-temperature industrial furnaces, middle-temperature industrial furnaces and low-temperature industrial furnaces. The device in a vertical structure, fireproofing materials are used as inner lining, and furnace walls are not cooled by water. The present invention comprises a first-stage gasifying chamber, a connecting segment and a second-stage combustor, wherein the gasifying chamber is divided into an upper chamber and a lower chamber by a shrinkage opening structure in the gasifying chamber; in the upper chamber, coal powder is combusted to generate low-heat value gas under the condition that alpha is equal to 0.55 to 0.75; hot coal gas is distributed to a second-stage injection-type combustor by the connecting segment to be mixed with the tertiary air; the hot coal gas is led in an industrial furnace chamber so as to realize complete combustion. The combusting device has the advantages of high combustion efficiency, 70 to 95% of slag collecting rate, and little generation amount of NOx.

Description

Coal gasifying burner

The present invention relates to the multilevel combustion device of a kind of fine grained, especially the coal dust multilevel combustion device of forming by the vaporizer and the second level secondary burner of first order spiral-flow type to the pulverulent solids fuel gasification combustion.

The direct combustion heat supplying efficient of coal is low, seriously polluted, with burning again after the coal gasification, can overcome the shortcoming of direct burning, but the investment of existing coal gasifier is big, efficient, the free of contamination combustion method of the coal of easy row so people seek letter always.

Magazine " Industrial Heating " 11 phases in 1985 " Versatile Slagg-ing Coal Combustion System Designed for Energy Efficency Without Pollution ", magazine " fuel and burning " (day) 1992 3, " exploitation of coal partial combustion stove (CPC) technology " in April number, Chinese patent CN2050929U " Cyclonic coal powder burner " and CN2051324U " liquid deslagging powdered coal cyclone burning device " have all introduced and have adopted the different pulverized coalapparatus of spiral-flow type structure, preceding two kinds of purposes are to solve the boiler replace oil with coal, produce pollution problems when gas is made fuel, back two kinds is purpose to be used for the heater for rolling steel heat supply then.They are horizontal placement, adopt the slag tap mode, the furnace wall water-cooled, and the common drawback that they exist is:

1, the water-cooled heat loss is big.Not only reduce effective heat supply heat, and consumed a large amount of cooling waters.

2, coal accommodation is narrow.To the coal of high ash melting point, the deslagging difficulty.

3, load regulation range is little.Thereby be difficult for satisfying adjustment in the technical process.

Magazine " industry heating " (day) in November, 1989 number " application of cycle stream combustion furnace " has been introduced a kind of burner of vertical, air-cooled liquid-bath combustion industry mud coal, and its adopts the oxygen-enriched combusting that pressurizes, the body of heater with slim-lined construction type.This article does not adopt again under the situation of water-cooled at the pressurization oxygen-enriched combusting its burner, how to guarantee that furnace lining uses reliably and with long-term, does not produce evidence.

The purpose of this invention is to provide a kind of coal powder burner that is applicable to various industrial furnace heat supplies, it has certain coal gasification degree, the higher lime-ash trapping ability and the thermal efficiency, can fit different atures of coal and big load regulation range, and the furnace wall does not have water-cooled.

For achieving the above object, the technical solution used in the present invention is: burner is designed to vertical type garden tubular construction, and it comprises first order spiral-flow type vaporizer, connecting section and second level injection burner.In the first order, be provided with the throat structure of peripheral one-tenth garden, edge annular in the vaporizer, the vaporizer of spiral-flow type is separated to become upward chamber and following chamber, a wind, coal dust intermixture sprays into from the cyclone on top, last chamber, secondary wind tangentially sprays into from the circuit each point spout that is uniformly distributed in sidewall, two strands of air-flows are simultaneously in the rotation of gasification indoor high-speed, mix mutually, the metering function of reducing in addition, the chamber forms the center backflow and the ring casing backflow of open type on vaporizer, the special flow field structure of last chamber helps pulverized coal particle and air rapid mixing and burning, and can stop fine coal dust of part and lime-ash to be taken out of the chamber prematurely, make them be arranged enough time of staying in last chamber.The total air of control primary and secondary air makes air coefficient α=0.55～0.75, and coal dust carries out imperfect combustion under the condition of air capacity deficiency, generates the high temperature low-heat value gas that contains fuel gas such as carbon monoxide, hydrogen.High-temperature fuel gas enters the second level via connecting section, in the further dedusting of connecting section and be assigned to second level injection burner and mix mutually with tertiary air, sprays into the industrial furnace burner hearth and carries out completing combustion.Injection burner can be made of as central tube the tertiary air jet pipe, also can become periphery to inject form by tertiary air and constitute.Solid granulates slag chamber under vaporizer of the major part formation cohesion of coal ash slag is captured and discharges from the slag runner of following bottom, chamber.Whole burner is a liner with the refractory material, and the furnace wall does not have water-cooled.The chamber also can feed part steam according to actual needs on vaporizer.

In the refractory material furnace wall of chamber, built secondary wind air annular intake adit by laying bricks or stones on the vaporizer, be provided with part flow arrangement in the structure of circular passage and evenly spray to guarantee each spout wind.Secondary wind air circular passage can be carried out from preheating secondary wind, and the liner of also refractory material being built by laying bricks or stones simultaneously plays cooling protection.

The throat structure that is provided with in the vaporizer is flat, also can be staged or inclined-plane, the current limliting of reducing cooperates with the swirling eddy of last chamber can play the supporting effect, make pulverized coal particle repeatedly circulation rotation in reducing, not only prolonged the time of staying of pulverized coal particle, carbon residue is further gasified, guarantee that gasification reaction is accomplished, and provide grey slag particle to collide to agglomerate into the condition of larger particle, improved retention efficiency, retention efficiency can reach 70-95%.

The bottom, chamber is provided with the water seal slag notch under the vaporizer, sidewall has connecting section, connecting section is that high-temperature fuel gas enters partial passage by the first order, according to actual conditions and needs, connecting section can be designed to the shape of various needs, combustion gas enters the second level after this further dedusting, the flying dust that is deposited on connecting section is got rid of from ashpit.

This burner is because the uniqueness of type of furnace design, make and present special flow field structure in the vaporizer, the heat and mass condition is good, and the cooperation of primary and secondary air is reasonable in addition, and coal dust and air mix in vaporizer, rapidly fire burns and enough time of staying are arranged in vaporizer, assurance reacts completely, so mechanical incomplete combustion is very little, and the furnace wall does not have water-cooled in addition, heat loss is also very little, so efficiency of combustion is up to more than 96%.

By adjusting to primary and secondary air, can control indoor reaction temperature, make most of coal ash slag become solid-state cohesion slag to discharge, the supporting effect of reducing and backflow has prolonged the time of staying of particle, and carbon residue is further gasified, and has also increased soot particle and has collided the condition that agglomerates into larger particle mutually, the further dedusting of connecting section in addition, can guarantee that retention efficiency reaches 70～95%, therefore, the combustion gas that infeeds the industrial furnace burner hearth is clean relatively.

Suitably regulate the coal supply amount, primary and secondary air air quantity etc. can adapt to coal and change or load variations.

The reaction temperature of last chamber is controlled in 1100 ℃ of-1400 ℃ of scopes; secondary vane road be arranged on self-preheating secondary wind the time also reduced the temperature of liner; liner is played a protective role; thereby this burner adopts refractory material to do liner; the furnace wall does not have water-cooled, can obtain the high life in stove village.

Because multistage combustion, NOx content is low in the combustion product, does not cause environmental pollution.So, this burner be a kind of make coal dust gasification, energy-efficient, from the novel burner of dedusting, low NOx.

Coal gasifying burner type approval test of the present invention at first is used for the stepping bed formula continuous furnace of φ 200 * 5 milling trains, this burner that adopts is hour coal consumption 200Kg's, be equipped with the coal supply of FM-200 type fan mill, situation such as table 1 before and after the statistical test of test operation operation back:

Table 1

	Average coal consumption (Kg/ ton material)	Minimum coal consumption (Kg/ ton material)	Average class produces (ton)	The highest class produces (ton)
	Average coal consumption (Kg/ ton material)	Minimum coal consumption (Kg/ ton material)	Average class produces (ton)	The highest class produces (ton)	Before the test	165	156	10.348	19.447
Result of the test	96.58	63	13.72	21.987	Before the test	165	156	10.348	19.447

Find out that thus this coal gasifying burner energy-saving effect is remarkable.After measured, retention efficiency is up to 93.06%, and is average 1.25% to the billet oxidization burning loss amount, improved the lumber recovery of steel billet, and load regulation rate is big, the efficiency of combustion height, and workshop condition is greatly improved, and chimney emits white cigarette, and lingemann blackness is zero, and soot emissions are up to standard.

Be described in further detail below in conjunction with drawings and Examples.

Fig. 1 is a burner schematic diagram of the present invention.

Fig. 2 is the A-A generalized section of Fig. 1.

Fig. 3 is a vaporizer flow field schematic diagram.

By accompanying drawing as can be known, one time wind, coal dust intermixture are sprayed into to rotation from last chamber 3 top axle by cyclone 2 through pipeline 1, secondary wind enters secondary vane band 5 by secondary wind inlet 6 and is tangentially sprayed into from last chamber sidewall by uniform a plurality of spouts 4, be provided with part flow arrangement in the secondary vane band, to guarantee that each spout wind evenly sprays, in the last chamber, wind nozzle diameter and last chamber diameter ratio are 0.15～0.45, and the section calorific intensity of last chamber is 12 * 10 ⁶KJ/m ²～25 * 10 ⁶KJ/m ², the distance of an overfire air port and a wind nozzle is good with 250～500mm.Throat structure 10 is positioned at vaporizer middle part, is to go up 0.6～1.4 times of chamber diameter apart from the distance of overfire air port.Throat structure is a tabular, and reentrant diameter and last chamber diameter ratio are in 0.5～0.8 scope, and reducing thickness is good with 50～150mm.The furnace wall constitutes no water-cooled by refractory material 7, heat-barrier material 8, steel plate 9 are compound.Because unique furnace type structure, the high speed rotation of going up indoor air flow and the metering function of reducing have formed the backflow of open type center and the ring casing that help pulverized coal particle and air rapid mixing and burning in last chamber and have refluxed.Suitably regulate the primary and secondary air air quantity, to adapt to coal or load variations, make chamber air coefficient α=0.55～0.75, coal dust carries out imperfect combustion under the condition of air capacity deficiency.By adjusting to the primary and secondary air air quantity, can control indoor reaction temperature in 1100 ℃ of-1400 ℃ of scopes, make most of lime-ash become state of aggregation.When fully not reacting the soot particle that contains the part carbon residue, when coming downwards to reducing 10 places, because the supporting effect of reducing and air-flow, make particle repeatedly circulation rotation in reducing, along with amounts of particles on the throat structure constantly increases, particle is grown up gradually, and the cohesion solid impurity particle that becomes bulk is constantly squeezed and the slag-drip opening 12 that falls to down chamber 11 enters in the slag runner 13.Above-mentioned slagging process is to realize in furnace temperature is 1100 ℃-1400 ℃ scope, thereby general high RUL, highdensity high-alumina brick, mullite brick, sillimanite brick etc. all can need not the high life that water-cooled can obtain furnace lining as furnace lining material.Owing to regulate by furnace temperature, can realize that lime-ash becomes state of aggregation, avoided the problem of slagging scorification and deslagging difficulty to take place, the version that last chamber is special and the adjusting of air quantity have guaranteed this effect.With the stove cigarette blow out go up the chamber than fine grained, obtain bigger kinetic energy in reducing place and enter chamber down, under reducing owing to racing takes place in air-flow expansion suddenly, the part of these particles (particle diameter is more than 10～20 microns) is separated again, fall within down the chamber slag runner, the lime-ash that is captured adopts artificial or the machinery discharge by the slag runner of water seal.Jie Jing high-temperature fuel gas arrives secondary burners 16 through connecting section 14 relatively, and connecting section is that the passage of high-temperature fuel gas can be designed to different shape with actual conditions again as required, plays the further dedusting of combustion gas, and the flying dust of deposition is removed from ashpit 17.Add tertiary air at secondary burner, the injection type secondary burner 16 that is made of as central tube tertiary air jet pipe 15 sprays into high-temperature fuel gas and air in the burner hearth 18 of industrial furnace and carries out completing combustion.

Coal gasifying burner of the present invention can be designed to from the various models of 200Kg coal/h～2000Kg coal/h according to actual needs, can be used for heater for rolling steel, also can be used for industrial furnaces such as forge furnace, heat-treatment furnace, tunnel cave, roller kilns, can be by one or more coal gasifying burner heat supplies.

Claims

1, a kind of coal gasifying burner, for vertical type columnar structured, it comprises first order spiral-flow type vaporizer, connecting section and second level burner, it is characterized in that: be provided with throat structure (10) in the first order spiral-flow type vaporizer vaporizer is separated into chamber (3) and following chamber (11), top, last chamber sprays into wind one time, the cyclone of coal dust intermixture (2), last chamber periphery is provided with uniform tangential secondary wind ejiction opening (4), there is water seal slag notch (12) following chamber, chamber under the vaporizer (11) sidewall communicates with connecting section (14), the joint that leads to burner hearth (18) at connecting section (14) is provided with second level injection burner (16), whole burner adopts refractory lining, and the furnace wall does not have water-cooled.

2, coal gasifying burner according to claim 1 is characterized in that: on the vaporizer in the chamber, wind nozzle diameter and last chamber (3) diameter ratio are 0.15～0.45, and the section calorific intensity of last chamber is 12 * 10 ⁶KJ/m ²～25 * 10 ⁶KJ/m ², the distance of overfire air port and primary wind and powder nozzle is good with 250～500mm, secondary wind is assigned to each spout via the air circular passage and sprays into indoorly, is provided with part flow arrangement in the structure of circular passage.

3, coal gasifying burner according to claim 1, it is characterized in that: throat structure is flat, stepped or inclined-plane, reentrant diameter and last chamber (3) diameter ratio are in 0.5～0.8 scope, reducing thickness is good with 50～150mm, and reducing is to go up 0.6～1.4 times of chamber (3) diameter apart from the distance of overfire air port.

4, coal gasifying burner according to claim 1 is characterized in that: the total air of control primary and secondary air makes air coefficient α=0.55～0.75, and vaporizer is slagged tap and is solid-state cohesion slag.