CN1205766A

CN1205766A - A Boundary Layer Coal Nozzle Apparatus for Steam Generator

Info

Publication number: CN1205766A
Application number: CN 96199211
Authority: CN
Inventors: J·S·曼
Original assignee: Combustion Engineering Inc
Current assignee: Combustion Engineering Inc
Priority date: 1995-12-22
Filing date: 1996-10-28
Publication date: 1999-01-20

Abstract

A steam generating apparatus (10) includes a pulverized coal and air nozzle comprising an elongated generally cylindrical nozzle body (30) having a nozzle in an axial portion thereof. The apparatus also includes a nozzle tip (34), the nozzle tip (34) being generally sleeve-shaped and configured to cover an end of the nozzle body (30). The nozzle tip (34) is configured to rotate about the end of the nozzle body (30), and the nozzle tip (34) includes first and second surfaces (58,59) configured to receive all flow from the nozzle body (30) therebetween. The apparatus also includes a seal plate (50), the seal plate (50) being generally sleeve-shaped and configured to form a seal between the tip end and the nozzle tip (34). The seal plate (50) is configured to rotate about the end of the nozzle body (30) and is formed with third and fourth surfaces (52,54), the third and fourth surfaces (52,54) being disposed adjacent the first and second surfaces (58,59), respectively, in all possible rotational positions of the seal plate (50) and the nozzle tip (34). This adjacent relationship forms an elongated slit for air flow. The seal plate (50) includes a stop device (56) for limiting relative rotation between the nozzle tip (34) and the seal plate (50). In certain aspects of the invention, the first and second surfaces (58,59) are planar. The third and fourth surfaces (52,54) may be cylindrical surfaces. The stop member (56) may include at least one upstanding member disposed on the seal plate (50). The seal plate (50) may include first and second planar opposing sides joined by third and fourth surfaces (52, 54). In some aspects, the third and fourth surfaces (52,54) have concave portions that are oppositely disposed. The stop member (56) may be part of first and second planar opposed sides and may include at least one ear on each of the first and second sides and, in some cases, a second ear on each of the first and second sides. All of the ears may be generally planar and each ear may be coplanar with one of the sides.

Description

A kind of boundary layer coal nozzle assembly that is used for steam raising plant

The present invention relates to a kind of coal dust be flowed to the conveying device of the coal of coal-fired steam generator, relate in particular to the nozzle arrangements that is used to carry coal.Coal-fired furnace is provided with a plurality of carrier pipes usually, is imported into a plurality of fuel-air input block by these carrier pipe coal dusts, and this input block is arranged in each vertically extending bellows.Bellows are arranged on one or more furnace walls, and coal and air are imported heating furnace.The design of such nozzle must consider that nozzle will be exposed under the temperature that substantially exceeds 1500 degrees Fahrenheits.

Prior art also comprises and resembles United States Patent (USP) 5,435, the standard coal spray nozzle device that is used for steam raising plant shown in 492, and this license is in Ronald J.Tenerowicz, and has the assignee identical as the application.

Known nozzle arrangements is subject to the influence of malformation and damages, and this malformation results from the radiant heat when stopping using for a long time.For example, if heating furnace moves under the situation less than heap(ed) capacity, be not that all nozzles are all worked so.The nozzle of not working is subjected to being produced by the radiant heat of heating furnace distortion.Known nozzle arrangements also is subject to the malformation influence when the lit-end coal dust of coal nozzle and damages.This malformation generally results from the temperature difference between the nozzle each several part, and the heat radiation that this temperature difference is produced by the burning in nozzle causes.

The most serious in being called " flame attach nozzle " about the temperature problem around the nozzle.This flame attach nozzle impels flame near nozzle.When the fuel of burning high-sulfur and/or high ferro, the problem that is produced by high temperature is also relatively more serious.Especially, the coal sulfur-bearing be 1.5% or more and/or iron content surpass 10% or problem is more obvious more for a long time.These problems more can increase the weight of under critical transmission condition.These conditions occur in, and for example, when Hot-air fan is too little, it is too little to regulate air hose, working space again enough not greatly, when perhaps system moves under the condition of high height above sea level.

When the coal dust of burning high-sulfur and/or high ferro under critical traffic condition, will produce a low-pressure area at end regions, low-pressure area is to be blocked and the surface that forms suppresses generation by fuel and coal ash.Specifically, along with temperature is increased to softening temperature greater than coal, will produce known " coating separation " phenomenon.Like this, the continuous operation that is under this condition will cause the distortion of end.This distortion will influence the performance and the service life of nozzle.

An object of the present invention is to provide a kind of device of avoiding the nozzle head distortion, the distortion of wherein said end is present in the prior art constructions.

Another object of the present invention provides the gratifying device of operation, even the content of sulphur and/or iron oxide is obvious in the coal.

Another purpose of the present invention provides a kind of device that makes nozzle head avoid its temperature effect.

A further object of the present invention provide a kind of can removing slag or the sedimental device of coal ash, the deposit of wherein said slag and coal ash is deposited in the nozzle when nozzle quits work.

Another object of the present invention provides a kind of lower device of structure manufacturing cost of relative prior art.

Find out: these purposes of the present invention and other purpose can realize in a steam raising plant, wherein steam raising plant comprises that one is used for the nozzle of coal dust and air, this nozzle comprises an elongated cylindrical nozzle body, and this nozzle body is provided with a spout on the one axial component; This device also comprises a nozzle head, and this nozzle head is a sleeve shaped, and is designed to the end of covering nozzles body; This nozzle head is provided with to such an extent that can rotate around the end of nozzle body and it comprises first and second surfaces, and first and second surfaces are designed and are configured to hold all flows that come from nozzle body between these two; This device also comprises a sealing plate, and sealing plate is a sleeve shaped also generally, and is configured to and can provides sealing between nozzle head and described end; The sealing plate is configured to and can rotates around the end of nozzle body; The sealing plate is also processed and be configured with third and fourth surface, and third and fourth surface is close to first and second surfaces respectively and is provided with on sealing plate and all possible turned position of nozzle head; This proximity relations forms an elongated slot, as air duct; The sealing plate also comprises a stop component, with relatively rotating between limits nozzle head and the sealing plate.

In forms more of the present invention, first and second surfaces are planes.Third and fourth can be the cylindrical shape face, and stop component can comprise that at least one is contained in the upright on the sealing plate.Sealing plate can comprise the first and second flat sides of settling relatively and be connected by third and fourth surface.In some form of the present invention, there is recessed part on third and fourth surface, and recessed portion is oppositely arranged.

Stop component can be the part of the relative side on first and second planes, and can comprise at least one lug that is arranged on first side and second side, in some cases, can comprise second lug that is arranged on first side and second side.All these lugs generally are in the same plane, and each lug all can with one of side coplane.

With reference to accompanying drawing, the present invention will be easier to understand, wherein:

Fig. 1 is a kind of vertical cross section of using steam raising plant of the present invention;

Fig. 2 is the front view of the sealing plate of prior art;

Fig. 3 is the plan view of the sealing plate of prior art shown in Figure 2;

Fig. 4 is the side view of the sealing plate of prior art shown in Figure 2;

Fig. 5 is the front view of the sealing plate of a kind of form according to the present invention;

Fig. 6 is the plan view of sealing plate shown in Figure 5;

Fig. 7 is the side view of sealing plate shown in Figure 5;

Fig. 8 is a cutaway view along vertical plane, has showed when nozzle moves to maximum upper position the relation in this nozzle between each part;

Fig. 9 is a cutaway view along vertical plane, has showed when nozzle moves to maximum lower position the relation in this nozzle between each part.

With reference to Fig. 1, show heating furnace 10, this heating furnace 10 is a kind of heating furnaces of the present invention of using.Heating furnace 10 is vertically placed, and the outlet of burning gases is arranged in the top.The prolongation of this outlet is a lateral gas passage 12, and it links to each other with the upper end of a vertically extending gas passage 14 and a blast pipe (not shown).Heating furnace shown in this is provided with a combustion chamber 16.Heating furnace 10 has an antetheca 22 and a rear wall 24.Keeping at a certain distance away is provided with the sidewall (not shown), and this sidewall connects antetheca 22 and rear wall 24.

Preferably see Fig. 8 and Fig. 9, usually, the coal nozzle has an elongated nozzle body 30, and a flap nozzle head 34 is housed on the nozzle body, and nozzle head 34 can rotate around bearing pin 36.Usually, nozzle head 34 can be from itself and the moving in 25 ° the scope relative to centering or coaxial position of nozzle body 30 up or down.Between nozzle head 34 and nozzle body 30, a sealing plate is set.According to the sealing plate 50 of a kind of form of the present invention shown in Fig. 5-9.When nozzle head is mobile in whole shown in Fig. 8 and 9 can mobile scope, sealing plate 50 relative nozzle head 34 sealed-in nozzles bodies 30.

Nozzle body 30 is provided with a upper horizontal flanges 30A and a bottom horizontal flanges 30B, and flange 30A and 30B make progress, extend downwards from nozzle body 30 respectively.Specifically, flange 30A and 30B are generally the plane of flaring, and separate from opposite opposed both sides of dividing the horizontal plane (not shown) of this nozzle body 30 equally on these two planes.Sealing plate 50 comprises one first cylinderical surface 52 and one second cylinderical surface 54.These surfaces are meshed with free edge surface 30C, the 30D of flange 30A and 30B respectively.

The bearing pin 36 that is supported by the carriage (not shown) that is connected on the nozzle body 30 is supporting nozzle head 34 and sealing plate 50, to make it rotation.More particularly, see Fig. 8 and 9, nozzle head 34 is a rectangle, although this nozzle head 34 can be columnar or foursquare in other embodiments.Being arranged in the nozzle head is two general

flat boards

58,59, these two flat boards, 58,59 contiguous ground, and roughly settle with each outer surface of

cylinderical surface

52,54 tangently.More particularly,

plate

58,59 distance circle

cylindrical surface

52,54 about two inches respectively.This spacing is enough to prevent to flow through between the coal

dust slave plate

58,59 of nozzle body 30 and each

cylinderical surface

52,54 substantially to be passed through.Therefore, the fluid that flows through nozzle body 30 is only derived nozzle head 34 by being positioned at

plate

58,59 middle nozzle head 34 parts.In addition, parallel-

plate

62,64 is with respect to the flat line offset of geometrical axis of nozzle head 34.

Plate

62,64 is used for to passing through the movement-oriented of nozzle head 34 and promoting laminar flow.

Be in operation, nozzle head 34 can be positioned on a plurality of angle positions in 50 ° of whole possible scopes of its activity by general mechanism's (not shown).The selection of position is decided by the needs of best combustion.Primary air and coal dust pressurized by nozzle body 30, sealing plate 52 core and be positioned at nozzle head 34 parts in the middle of the plate 58,59.Secondary air (1) is imported into the part that is arranged in

plate

58,59 outsides of nozzle head 34 along nozzle body 30 outer surfaces; And (2) are imported in two inches high slots of

plate

58,59 and sealing plate 52 centres.Will be appreciated that each slot of two inches high has all prolonged the width of nozzle head 34.For many application, need be to be higher than the speed guiding secondary air of primary air by nozzle body 30.This length velocity relation purpose is when secondary air flows with the speed that is higher than flame propagation, prevents that flame is detained.The guiding secondary air enters and makes the boundary layer that has produced air on the inner surface of

plate

58,59, the boundary layer of this air can prevent that these plates are subjected to being conducted through the abrasion that a large amount of coal dusts of nozzle head 34 cause in the slot.

In this most preferred embodiment, sealing plate 30 is provided with first and second lugs at the axial end place of cylinderical surface 52.In addition, sealing plate 50 also is provided with first and second lugs in the axial end of cylinderical surface 54.Illustrated most preferred embodiment generally comprises the lug on plane or the stop component 56 of ear shape.Those skilled in the art should be realized that in other embodiments of the invention, and stop component can be L shaped, annular pin, square block or any other shaped element.

Fig. 8 shows and is configured in the nozzle head 34 of maximum upper position with drainage.Secondary fluid along the outer surface axial lead of nozzle body 30 imports the interior zone that is arranged at the

plate

58,60 in the nozzle head 34 respectively as can be seen.Separated lug 56 can not hinder substantially second air stream along the outer surface of nozzle body 30 flow promptly (1) enter nozzle 34 parts and (2) that are positioned at

plate

58,60 outsides and enter between two inches high slots of

plate

58,60 with sealing plate 52 centres.

Can be clear that lug 56 among Fig. 8, when nozzle head 34 rotates to maximum upwards position, be in the edge of lug 56 adjacent plates 58 of cylinderical surface 52 axial end.Thereby can find out that mechanism's (not shown) that nozzle head 34 is rotated causes that sealing plate moves along flange 30A, arrives the spout of nozzle body 30 up to the edge of sealing plate.Certainly, moving of sealing plate 50 is the rotation around bearing pin 36, and wherein bearing pin 36 matches with the hole 60 of centering, and hole 60 is positioned on its each sidewall 61.

Fig. 9 shows when nozzle head 34 is in the position of maximum pilot flow downwards, is connected accordingly between the lug 56 of plate 60 and the axial end that is arranged at cylinderical surface 54.

As if the present invention compares with the prior art shown in Fig. 2-4, have only a slight variation.But this variation has produced very important meaning.Sealing plate 40 is with the difference of sealing plate 50: the latter does not comprise lug 56.Replace this structure and have the flange 42 that extends laterally, this flange 42 extends along an edge of each cylinderical surface 52 and cylinderical surface 54.Seen that these flanges 42 have stoped secondary air mobile along the outer surface of nozzle body 30, use the effect that device of the present invention reached thereby can not produce.Advantageously, the device low cost of manufacture of the prior art shown in device comparable Fig. 2-4 according to the present invention.Because structure of the present invention needs less material and less manufacturing time and cost, so produced such effect.

An obvious advantage of the present invention need not the nozzle head 34 of prior art is made change for the beneficial effect of realizing the present invention exactly.Like this, the present invention just is easy to reequip on existing equipment, and is easy to transform product in the future.The present invention advantageously produces a boundary layer, and this boundary layer can prevent that nozzle arrangements is subjected to the influence of heat and the abrasion that is produced by a large amount of coal dusts by this device.

With reference to the most preferred embodiment that has illustrated, the present invention has made explanation.Those skilled in the art may carry out other variation according to the disclosed technology contents of this paper.Believe that this variation only also falls in the scope of the disclosure by the present invention that following claim limited.

Claims

1. A nozzle arrangement for use with an associated steam generating arrangement comprising:

an elongated generally cylindrical nozzle body having a nozzle at one axial portion thereof;

a nozzle tip, said nozzle tip being generally sleeve-shaped and positioned to cover the end of said nozzle body, said nozzle tip comprising first and second surfaces configured to receive therebetween all source at the flow rate of the nozzle body, and

a sealing plate, generally sleeve-shaped, positioned to form a seal between said end and said nozzle tip; said sealing plate being configured to surround the end of said nozzle body Rotation; said seal plate is arranged to have its third and fourth surfaces, the third and fourth surfaces in all possible rotational positions of said seal plate and said nozzle head respectively with said first and second the surfaces are disposed adjacently so as to form an elongated slot; and said sealing plate includes a stop means to limit relative rotation between said nozzle tip and said sealing plate.

2. The device of claim 1, wherein said first and second surfaces are planar.

3. The device of claim 2, wherein said third and fourth surfaces are cylindrical surfaces.

4. The device of claim 3, wherein said stop means comprises at least one upstanding member disposed on said sealing plate.

5. The apparatus of claim 4, wherein said sealing plate includes first and second planar opposing sides joined by said third and fourth surfaces.

6. The device of claim 5, wherein said third and fourth surfaces have recessed portions, and said recessed portions are oppositely disposed.

7. Apparatus as claimed in claim 6, wherein said stop means is part of one of said first and second opposed planar sides.

8. The device of claim 7, wherein said stop means includes at least one ear on each of said first and second sides.

9. The device of claim 8, wherein said stop means includes a second ear on each of said first and second sides.

10. The device of claim 9, wherein all of said ears are generally planar.

11. The device of claim 10, wherein each of said ears is coplanar with one of said sides.

12. A steam generating device, comprising:

a heating furnace;

at least one nozzle assembly comprising an elongated generally cylindrical nozzle body having a nozzle on an axial portion of the nozzle body;

a nozzle head, said nozzle head being generally sleeve-shaped and formed to cover the end of the nozzle body, said nozzle head being configured to rotate about said end of said nozzle body, said nozzle head comprising first and a second surface, the two surfaces being arranged to accommodate all flow originating from the nozzle body, and

a sealing plate, said sealing plate being generally sleeve-shaped, arranged to form a seal between said end and said nozzle tip; said sealing plate being configured to surround said end of said nozzle body Rotation; said seal plate is arranged to have its third and fourth surfaces, the third and fourth surfaces in all possible rotational positions of said seal plate and said nozzle head respectively with said first and second the surfaces are disposed adjacently so as to form an elongated slot; said seal plate includes a stop means to limit relative rotation between said nozzle tip and said seal plate, said stop member being spaced from said elongated slot set up.

13. The device of claim 12, wherein said first and second surfaces are planar.

14. The device of claim 13, wherein said third and fourth surfaces are cylindrical in cross-section.

15. The device of claim 14, wherein said stop means comprises at least one upstanding member disposed on said sealing plate.

16. The apparatus of claim 15, wherein said seal plate includes first and second planar opposing sides joined by said third and fourth surfaces.

17. The device of claim 16, wherein said third and fourth surfaces have concave portions, and said concave portions are oppositely disposed.

18. Apparatus as claimed in claim 17, wherein said stop means is part of one of said first and second opposed planar sides.

19. The device of claim 18, wherein said stop means includes at least one ear on each of said first and second sides.

20. The device of claim 19, wherein said stop means includes a second ear on each of said first and second sides.