US3359948A

US3359948A - Steam producer with radiation flue

Info

Publication number: US3359948A
Application number: US515370A
Authority: US
Inventors: Knizia Klaus
Original assignee: L&C Steinmueller GmbH
Current assignee: Hitachi Zosen Inova Steinmueller GmbH
Priority date: 1964-12-24
Filing date: 1965-12-21
Publication date: 1967-12-26
Anticipated expiration: 1984-12-26
Also published as: DE1426727A1

Description

Dec. 26, 1967 Zl 3,359,948

STEAM PRODUCER WITH RADIATION FLUE I Filed Dec. 21, 1965 3 Sheets-Sheet 1 1967 K. KNlZIA 1 r 3,359,948

STEAM PRODUCER WITH RADIATION FLUE 3 Sheets-Sheet 2 Filed Dec. 21, 1965 FIG. 20

FIG. 2

m lulnm 1m ul IIIIIIIIIIOIIQII! llll I'lllllllln IIIILiIILfl 2 B an 3 .1. n f x milzmimimywz /iw/ Dec; 26, 1967 Y KN|Z|A 3,359,948

STEAM PRODUCER WITH RADIATION FLUE Filed Dec. 21, 1965 s Sheets-Sheet s United States Patent 3,359,948 STEAM PRODUCER WITH RADIATION FLUE Klaus Knizia, Gummersbach, Germany, assignor to L. & C. Steinmuller G.m.b.H., Gummersbach, Germany Filed Dec. 21, 1965, Ser. No. 515,370 Claims priority, application Germany, Dec. 24, 1964, St 23,137 Claims. (Cl. 122-235) The present invention concerns a steam producer with a vertical fire-box and with a vertical flue connected to the top portion of said fire-box.

It is known that return ceilings or walls directed toward the combustion chamber proper favorably aifect the combustion, reduce the combustion time and intermix the flue gases so that also the temperature distribution over the entire cross section of the radiation flue will be equalized. These return walls or the like are employed with boilers having front firing boxes and also with boilers having corner firing boxes.

With boilers having oppositely located burners (boxer arrangement), it is not possible for geometric reasons to draw the respective walls opposite the burners inwardly toward the fire-box to any material extent. Consequently, the flue gases in the center path have a considerably higher temperature than the flue gases adjacent the wall. This fact is particularly unfavorable when the flue equipped with contact heating surfaces follows the radiation flue without any material change in the direction of flow of the flue gases.

Similar conditions prevail with steam producers having corner fire-boxes. Attempts have been made to obtain an equalization of the temperature over the entire cross section by arranging hairpin-shaped tubes (twist impeders or rectifiers) which from opposite sides extend into the firebox and interengage each other in a comb-like manner. These inserts, however, have an effect which is precisely contrary to that aimed at by the present invention.

It is also known in connection with melting chamber boilers which are fired from two oppositely located sides to produce a turbulence in the melting chamber by arranging a displacement body in the central plane thereof. Such displacement body is in the form of a horizontal body having the shape of an isosceles triangle in cross section with its base at the bottom. The body is in the fire box above the burners and constricts the fire-box toward the sides above the burners and thereby separates from the main firing chamber two post-burning chambers in which the fire gases subjected to turbulence by the constrictions formed by the body will burn faster. With regard to the radiation flue, the post-burning chambers are, as customary,.separated by slag intercepting grates positioned at the upper ends of the post-burning chambers.

According to another heretofore made suggestion, a displacement body is suspended in the fire-box between opposed burners and at about the level of the burners. This displacement body is above the slag discharge opening and protects the zone above the slag discharge opening against radiation and also prevents an undesired radiation from the fire-box to the contact heating surfaces.

It is an object of the present invention with boilers having a substantially verticalflue, to provide an arrangement which in the flue will produce an eflective turbulence of the flue gases burned already to a considerable extent.

It is another object of this invention to provide an arrangement as set forth in the preceding paragraph which will equalize the temperature over the entire cross section of the flue.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 diagrammatically illustrates a steam producer with a vertical fire-box and a vertical flue adjacent thereto which in accordance with the present invention is provided with a displacement body of an equilateral triangular shape.

FIG. la is a cutaway drawing along line Ia-Ia.

FIG. 2 is a diagrammatic representation of a steam producer according to the invention similar to that of FIG. 1 but differing therefrom in that the displacement body has a diamond or rhombus shape. j

FIG. 2a is a cutaway drawing along line IIaIIa.

FIG. 3 illustrates the scheme of a steam producer according to the present invention.

The steam producer according to the present invention which has a vertical fire-box and a vertical adjacent flue and, if desired, may be equipped with additional heating surfaces, is characterized primarly by a cooled displacement body above the fire-box.

This displacement body forces the combustion gases which rise in the center and the temperature of which is considerably higher than the temperature of the combustion gases rising along the walls, to move toward said walls. In this way, a considerable turbulence is produced which will bring about an intense intermixing of the flue gases of different temperatures thereby causing an equalization of the temperature over the entire cross section of the flue. Normally, a displacement body which is not suspended in the central zone would produce a certain equalization of the temperature. However, the best result will be obtained when the displacement body is located in the central zone of the radiation flue.

' According to a further development of the present invention, the displacement body is suspended on supporting pipes so that it can move freely and independently of the longitudinal extension of the wall pipes.

Since, in order to be effective, the displacement body must have a certain size, while on the other hand it is suspended on supporting pipes the number of which is to be restricted as far as possible, it is advantageous for purposes o freducing the weight, to design the displacement body in the form of a hollow body. In this connection it is not necessary that the displacement body is closed on all sides. For producing a turbulence, a displacement body open at the bottom and having a roof-shaped cross section has proved highly advantageous. This cross section may be supplemented by inclined plates arranged in the flue at a higher or lower level than the lower surface of the displacement body. When the displacement body is closed on all sides, it is advantageous to fill the same with light mate'rial, as for instance light chamotte, in order, particularly when burning ash containing fuels, to prevent any collection of flue dust. The walls of the displacement body are at any rate formed by pipes through which a cooling medium passes.

When the flue has a rectangular cross section which is in most instances the case when the boiler is fired from oppositely located sides, the displacement body advantageously extends from one side wall to another one. A construction is, of course, also possible according to which the displacement body is not directly connected to the side walls but leaves free a flue gas passage so that elevated temperatures in the vicinity of the walls will be obtained. 7 q

With boilers having a considerable width, it may be advantageous instead of one displacement body to employ a plurality of displacement bodies which are arranged in series one behind the other and thus supplement each other over the entire width of the flue. The simpliest design will be obtained by designing the displacement body in the form of a straight beam and suspending the same horizontally in the flue. However, it is also possible to design the beam so that it will have a slight V-shape, in other words, is somewhat inclined toward the outside.

The cross-sectional shape of the displacement body is advantageously designed symmetrically. In this connection, the shape of an isosceles or of an equilateral triangle is advantageous which is vertical and the basis of which faces the fire-box. It is also possible to design the displacement body with a diamond-shaped cross section and to suspend the same in such a way that the lowermost point of the diamond is a tip. This shape makes it possible in a simple manner to provide a shroud or apron formed by evaporator pipes which are adjacent the lower end of the displacement body and if desired may extend close to the bottom. It is, of course, understood that also other cross-sectional shapes for the displacement body are possible, such as a cylindrical shape, with circular as well as with elliptical cross-section, or a drop-shaped cross section.

When the flue has a circular cross section or the cross section of a regular polygon, the best flow conditions are obtained by designing the displacement body as a body of revolution and suspending said displacement body at the longitudinal axis of the flue. In some circumstances, a dis-placement body in the form of a disc will suflice the plane of which is perpendicular to the longitudinal axis of the flue and which may have a circular cross section or a cross section conforming to the shape of the flue.

Referring now to the drawings in detail, the steam producer shown in each of the various embodiments illustrated therein comprises a fire-box 1, a radiation flue 2 and a flue 3 equipped with

contact heating surfaces

13, 23. These three chambers are vertically one above the other. Fire-box 1 is at its front side provided with two rows of

burners

4, 14 and at its rear side with two rows of burners 5, 15. The burner rows 4 and 5 are located opposite to each other and so are the

burner rows

14 and 15.

The contact heating surfaces 13, 23 arranged in flue 3 are formed by superheating pipes.

In conformity with the present invention, the radiation flue 2 which is covered with evaporation pipes has a displacement body 8 suspended therein, said body 8 being supported by supporting

pipes

9, 19, 29.

According to the arrangement shown in FIG. 1 and FIG. 1a, the displacement body has the shape of an equilateral triangle with the basis thereof extending along asubstantially horizontal plane. When the fire gases of the intermediate layers rise, they are deviated toward the outside as indicated by the

arrows

10, 20. As a result thereof they intermix with the outer flue gases and bring about an equalized or uniform temperature distribution in the cross section of the radiation flue above the displacement body 8.,

.The embodiment shown in FIG. 2 and FIG. 2a in which those parts which correspond to the parts of FIG. 1 and FIG. la have been designated with the same reference numerals as in the latter, differs from that of FIG. 1 and FIG. 1a primarily in that the displacement body 8a instead of being triangular has the shape of a diamond or rhombus. The displacement body 8a is formed by a plurality of pipes 11 through which a cooling mediumis passed.

It is, of course, to be understood that the present invention is, by no means, limited to the particular arrangements shown in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. In a steam producer, a vertical fire-box, rows of burners disposed along opposite walls so that flue gases in the central space have higher temperatures than those at the sides of the fire-box, vertical flue means of the same substantially uniform cross section extending vertically upwardly from said fire-box, including a first radiation section having a clear central space surrounded by radiation absorbing surfaces to extract heat by radiation, and a second section above ,said first section through which the flue gases pass from said first section, contact heating surfaces disposed in said second section to extract heat from said gases by contact, and means to distribute the gases of unequal temperatures equally through said second section comprising a displacement body of substantial lateral extent suspended parallel to said opposite walls and extending substantially across the top centrally of the first section immediately below the contact heating surfaces to deflect the hot gases of the central space toward the sides of the flue means to mix with the cooler gases along the sides.

2. A steam producer according to claim 1, in which said displacement body is formed by pipes adapted to be connected to a source of cooling fluid.

3. A steam producer according to claim 1, in which said displacement body has a symmetrical cross section in at least one vertical plane.

4. A steam producer according to claim 1, in which said displacement body is formed by a continuous beam having a length approximately corresponding to the width of said radiation flue.

5. A steam producer according to claim 1, in which said displacement body has an isosceles-shaped cross section with the plane thereof extending in the vertical direction of said flue means.

6. A steam producer according to claim 1, in which said displacement body has the cross section of a diamond standing on one of its tips.

7. A steam producer according to claim 1, which includes supporting pipes extending longitudinally in said flue means and supporting said displacement body.

8. A steam producer according to claim 1, which includes partition means arranged in said flue means adjacent said displacement body means and formed by superimposed pipes adapted to be connected to a source of cooling medium.

9. A steam producer according to claim 1, in which said displacement body is formed by a plurality of pipe means adapted to be connected to a source of cooling fluid and defining the outer surface of said, body, said body being filled with light material.

10. A steam producer according to claim 1, in which said displacement body is hollow, and which comprises reverse collector means arranged in said displacement body.

References Cited UNITED STATES PATENTS 1,922,664 8/1933 Kerr 122235 2,002,463 5/1935 Bailey et al. 122-235 2,672,849 3/1954 Fruit 122--333 2,982,265 5/1961- Wedertz 122-235 3,003,480 10/ 1961 Fink et al 122-235 FOREIGN PATENTS 806,997 1/ 1959 Great Britain. 1,194,599 5/ 1959 France.

KENNETH W. SPRAGUE, Primary Examiner,

Claims

1. IN A STEAM PRODUCER, A VERTICAL FIRE-BOX, ROWS OF BURNERS DISPOSED ALONG OPPOSITE WALLS SO THAT FLUE GASES IN THE CENTRAL SPACE HAVE HIGHER TEMPERATURES THAN THOSE AT THE SIDES OF THE FIRE-BOX, VERTICAL FLUE MEANS OF THE SAME SUBSTANTIALLY UNIFORM CROSS SECTION EXTENDING VERTICALLY UPWARDLY FROM SAID FIRE-BOX, INCLUDING A FIRST RADIATION SECTION HAVING A CLEAR CENTRAL SPACE SURROUNDED BY RADIATION ABSORBING SURFACES TO EXTRACT HEAT BY RADIATION, AND A SECOND SECTION ABOVE SAID FIRST SECTION THROUGH WHICH THE FLUE GASES PASS FROM SAID FIRST SECTION, CONTACT HEATING SURFACES DISPOSED IN SAID SECOND SECTION TO EXTRACT HEAT FROM SAID GASES BY CONTACT, AND MEANS TO DISTRIBUTE THE GASES OF UNEQUAL TEMPERATURES EQUALLY THROUGH SAID SECOND SECTION COMPRISING A DISPLACEMENT BODY OF SUBSTANTIAL LATERAL EXTENT SUSPENDED PARALLEL TO SAID OPPOSITE WALLS AND EXTENDING SUBSTANTIALLY ACROSS THE TOP CENTRALLY OF THE FIRST SECTION IMMEDIATELY BELOW THE CONTACT HEATING SURFACES TO DEFLECT THE HOT GASES OF THE CENTRAL SPACE TOWARD THE SIDES OF THE FLUE MEANS TO MIX WITH THE COOLER GASES ALONG THE SIDES.