US3633550A

US3633550A - Water pipe boiler

Info

Publication number: US3633550A
Application number: US11438A
Authority: US
Inventors: Willibald Kraus
Original assignee: Rheinstahl Henschel AG
Current assignee: Rheinstahl Henschel AG
Priority date: 1969-02-15
Filing date: 1970-02-16
Publication date: 1972-01-11
Anticipated expiration: 1989-01-11
Also published as: DE1907758B2; CH491320A; AT297749B; FR2032693A5; DE1907758A1

Abstract

A water pipe boiler having a circular or polygonal contour, which includes at least two heating surface cage bodies each comprising vertical pipes and upper and lower annular or polygonal headers or bends arranged coaxially one within the other in radially spaced relationship, while any of the individual cage bodies may be designed as evaporator, superheater, feed-water preheater or hot water generator.

Description

United States Patent lnventor Willibald Kraus Grebenstein, Germany Appl. No. 11,438 Filed Feb. 16, 1970 Patented Jan. 11, 1972 Assignee Rheinstahl Henschel Aktiengesellschaft Kassel, Germany Priority Feb. 15, 1969 Germany P 19 07 758.8

WATER PIPE BOILER 9 Claims, 3 Drawing Figs. U.S. Cl 122/235 R, 122/356 Int. Cl F22b 21/00 Field of Search 122/235 P, 323, 356

[56] References Cited UNITED STATES PATENTS 2,630,104 3/1953 Harvey 122/323 3,118,431 1/1964 Banker etaL. 122/323 2,271,880 2/1942 Wood 122/235 X 2,898,892 8/1959 Campbell et al 122/356 Primary Examiner-Kenneth W. Sprague Attorney-Walter Becker ABSTRACT: A water pipe boiler having a circular or polygonal contour, which includes at least two heating surface cage bodies each comprising vertical pipes and upper and lower annular or polygonal headers or bends arranged coaxially one within the other in radially spaced relationship, while any of the individual cage bodies may be designed as evaporator, superheater, feed-water preheater or hot water generator.

WATER PIPE BOILER The present invention relates to a water pipe boiler with a circular or polygonal design and with boiler pipes arranged vertically along the circumference of circular spiral or polygonal cross sections and forming draft guiding walls and with a horizontal flue gas flow through the high rectangular cross sections formed by the draft guiding walls.

Water pipe boilers are known in which between annular chambers there are vertical boiler pipes welded in, in such a manner, that they form gastight draft guiding walls. Between these walls, the flue gas flows horizontally along circular paths or along the circumferential line of the polygonal draft guiding walls through the free, relatively very narrow but high rectangular cross sections from the inside toward the outside. The flow cross sections along the flue gas path may be constant, or may be variable sectionwise, or in a continuous manner while the cross sections likewise decrease with decreasing flue gas temperature. With boilers of this type, it is disadvantageous that in view of the geometry of the annular chambers, they are suitable for only relatively small outputs and relatively low pressures.

It is, therefore, an object of the present invention to provide a water pipe boiler which has the advantages of the abovementioned flue gas guiding system, but which is adapted to realize higher and maximum unit outputs and also high pressures, also with superheaters and also with feed-water preheaters.

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

FIG. 1 represents a diagrammatic cross section through a water pipe boiler according to the invention with four cage heating surfaces.

FIG. 2 illustrates on a larger scale than FIG. 1 a cutout of a development of the cage heating surface of FIG. 1 with upper and lower annular headers.

FIG. 3 is a diagrammatic cutout of the cage heating surface with bends and finned pipes.

The above-outlined objects have been realized by the fact that two or more cage heating surfaces are provided, each of which consists of vertical pipes and upper and lower annular or polygonal headers or/and reversing bends, said cage heating surfaces being arranged substantially coaxially in radially spaced relationship to each other while the individual cage heating surfaces are differently designed so as to represent at least one evaporator, superheater, and/or feed-water preheater or hot-water generator.

According to the present invention, it is provided that one and the same cage has different heating surfaces, for instance, in the form of an evaporator and a superheater.

With regard to the flow through the cage heating surfaces, it is provided that the individual cage heating surfaces are passed through by a medium only in upward direction or only in downward direction or upwardly and downwardly while the number of the upwardly and downwardly passed through pipes equal each other or are different from each other. The number of the parallelly passed through pipes along the circumference of the cage heating surfaces varies. Moreover, it is provided that between two cages designed as draft guiding walls there are provided one or more cages preferably as superheaters. These superheaters are at both sides in contact with evenly tempered flue gases passing therealong while the vertical pipes in the direction of the flow of the flue gas are spaced from each other by a distance which equals or exceeds the diameter of the pipes.

With regard to the arrangement of the feed-water preheater, it is provided that between the outermost cage forming a draft guiding wall on one hand, and the flue gas chamber mantle on the other hand, there are provided one or more cages preferably in the form of feed-water preheaters which at both sides are passed around by evenly tempered flue gas and the pipes of which in the direction of flow of the flue gas are spaced from each other by a distance which equals or exceeds the diameter of the pipes. With the water pipe boiler according to the invention, vertical pipes pertaining to the cages may be employed which are equipped with fins, studs, or ribs.

Referring now to the drawing in detail, the cage heating surfaces l, 2, 3 and 4 are coaxially arranged with regard to each other while the cage heating surfaces 1 and 2 serve as draft guiding walls with tangent pipes. The cage heating surface 1 forms an evaporator (the evaporator pipes being marked by shading). All pipes of the cage heating surface 1 are passed through by boiling water in upward direction and they are at the upper and lower end welded into annular headers 7 (FIG. 2). The welded-in ends of the pipes are pulled in so as to assure a tangent pipe arrangement.

The cage heating surface 3 has likewise been built up of tangent pipes as well as upper and lower headers similar to the showing in FIG. 2. A portion of the cage heating surface 3 is formed by evaporator pipes (shaded), which are passed through in upward direction by boiling water and in conformity with FIG. 2 consist of superheater pipes 6 which are passed through by a medium in upward and downward direction. Directly adjacent to the evaporator pipes are superheater pipes 6 passed through by saturated steam. The annular headers are as to the medium separated into an evaporator part and a superheater part. Inasmuch as with increasing superheating the volume flow increases likewise, whereas the flue gas temperature and thus the required pipe inner cooling decreases, it is advantageous to correspondingly increase the number of the parallelly passed through pipes along the circumference.

From the directional arrows indicated in FIG. 2 it will be seen that first three pipes are passed through by the medium in downward direction, and finally, five pipes are passed through by the medium in upward direction. In the upper annular header 7 and the lower annular header 8, axial flows occur so that the annular headers 8 simultaneously act as mixing chambers. In conformity with the symmetrically off-flowing flue gas as indicated by the arrow in F IG. 10, also the steam in the cage heating surface 3 flows symmetrically to both sides of the boiler pipe and from the latter to the flue gas exit slot 11 of the cage heating surface 3.

The cage heating surface 2, designed as superheater and provided with upper and lower reversing bends 13 is arranged between the cage heating surfaces 1 and 3 forming draft guiding walls. In conformity with the arrows 10 in FIG. I, the cage heating surface 2 is, on both sides, passed by, by evenly tempered flue gas. The vertical superheating pipes of the cage heating surface 2 have in the illustrated example in the flow direction of the flue gas, a distance from each other which exceeds the pipe diameter.

In the illustrated example, between the outermost cage 3 forming a draft guiding wall, and the flue chamber mantle 12, there is provided the cage 4. This cage 4, which is designed as feed-water preheater, is provided with upper and lower bends 13 in conformity with FIG. 3 and also with finned pipes 14. This cage 4 is, in conformity with the arrows l0, likewise passed around on both sides by evenly tempered flue gas. Outside the flue gas chamber mantle 12 there is located the insulation 15. The combustion gases flow from the combustion chamber 16 in conformity with the arrows 10 through the slot 17 of cage 1, and through the slot 11 of cage 3 to the exit or discharge 18.

The advantages realized by the present invention consist primarily in that the individual cage heating surfaces may be manufactured independently of each other. These individual cage heating surfaces are easily subjected to a pressure test. Major repairs such as the replacement of old pipes are greatly simplified, inasmuch as individual cages can easily be exchanged. The structure according to the invention furthermore permits a considerable reduction in the manufacturing time, and also permits a simple manufacture of cage heating surfaces to be kept in stock.

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

What I claim is:

l. A water pipe boiler of a closed contour design, especially of a circular and polygonal contour design, which includes at least two closed heating surface cage bodies substantially coaxial with regard to each other and arranged open in radially spaced relationship to each other, each of said closed heating surface cage bodies comprising predominantly upright straight pipes arranged in wall to wall contact with each other and also comprising upper and lower connecting means respectively establishing flow connection between the upper ends and lower ends of said vertical pipes, said individual cage bodies being adapted to be connected to different sources of media for respectively running said cage bodies selectively as different types of cage bodies.

2. A boiler according to claim 1, in which said upper and lower connecting means are formed by headers permitting independent cage body expansion.

3. A water pipe boiler of a closed contour design, especially of a circular and polygonal contour design, which includes at least two heating surface cage bodies substantially coaxial with regard to each other and arranged in radially spaced relationship to each other each of said heating surface cage bodies comprising upright pipes arranged in wall-to-wall contact with each other and also comprising upper and lower connecting means respectively establishing flow connection between the upper ends and lower ends of said vertical pipes, said individual cage bodies being adapted to be connected to different sources of media for respectively running said cage bodies selectively as different types of cage bodies, said upper and lower connecting means being formed by bends.

4. A boiler according to claim 3, in which at least one and the same of said closed heating surface cage bodies comprises different grouped pipe types of cage bodies.

5. A boiler according to claim 4, in which at least one and the same of said closed heating surface cage bodies includes an evaporator heating surface and a superheater heating surface.

6. A water pipe boiler of a closed contour design, especially of a circular and polygonal contour design, which includes at least two heating surface cage bodies substantially coaxial with regard to each other and arranged in radially spaced relationship to each other, each of said heating surface cage bodies comprising upright pipes arranged in wall-to-wall contact with each other and also comprising upper and lower connecting means respectively establishing flow connection between the upper ends and lower ends of said vertical pipes, said individual cage bodies being adapted to be connected to different sources of media for respectively running said cage bodies selectively as different types of cage bodies, at least one and the same of said heating surface cage bodies comprising different types of cage bodies, different vertical pipes of one and the same type of cage body respectively being passed through by the respective medium in opposite directions.

7. A boiler according to claim 6, which includes two closed cage bodies forming draft guiding walls and also includes at least one superheater cage body interposed between said draft guiding walls in radially spaced relationship thereto so as to permit evenly tempered flue gas to pass openly on both sides of said superheater cage body, the vertical pipes of said superheater cage body being spaced from each other by a distance equaling at least the diameter of said last-mentioned vertical pipes.

8. A boiler according to claim 6, in which the outermost heating surface cage body forms a draft guiding wall and is surrounded in radially spaced relationship by the outer wall of said boiler, and which includes at least closed one cage body forming a feed-water preheater and being arranged in radially spaced relationship to and between said outermost cage body and said outer wall of said boiler to permit being passed by on both sides thereof by evenly tempered flue gas, the vertical pipes of said feed-water preheater bein spaced from each ot er by a distance equaling at least the iameter of said lastmentioned vertical pipes.

9. A boiler according to claim 6, in which said vertical pipes have enlargements increasing pipes surfacing on the outside thereof.

Claims

1. A water pipe boiler of a closed contour design, especially of a circular and polygonal contour design, which includes at least two closed heating surface cage bodies substantially coaxial with regard to each other and arranged open in radially spaced relationship to each other, each of said closed heating surface cage bodies comprising predominantly upright straight pipes arranged in wall to wall contact with each other and also comprising upper and lower connecting means respectively establishing flow connection between the upper ends and lower ends of said vertical pipes, said individual cage bodies being adapted to be connected to different sources of media for respectively running said cage bodies selectively as different types of cage bodies.

8. A boiler according to claim 6, in which the outermost heating surface cage body forms a draft guiding wall and is surrounded in radially spaced relationship by the outer wall of said boiler, and which includes at least closed one cage body forming a feed-water preheater and being arranged in radially spaced relationship to and between said outermost cage body and said outer wall of said boiler to permit being passed by on both sides thereof by evenly tempered flue gas, the vertical pipes of said feed-water preheater being spaced from each other by a distance equaling at least the diameter of said last-mentioned vertical pipes.