US2792815A - Water-cooled tubular framework for boilers - Google Patents

Description

May 21, 1957 F. STIPERNITZ WATER-COOLED TUBULAR FRAMEWORK FOR BOILERS Filed April 13, 1954 Inventor? F f, e I 1 WATER-COOLED TUBULAR FRAMEWORK FOR 7 BOILERS Franz Stipernitz, Gottingen, Germany, assignor to Heinrich Vorkauf, Berlin-Schmargendorf, Germany Application April 13, 1954, Serial No. 422,942

Claims priority, application Germany May 27, 1953 3 Claims. (Cl. 122-235) The invention relates to a water-cooled carrying frame work for boilers, such as steam generators, hot-water boilers and the like.

Boilers of a certain conventional type rather than being provided with a separate boiler framework have a tubular framework cooled by the boiler water and mostly formed like a cage. In such a framework, the horizontal tubes may serve for the connection of the tubes which constitute the heating surface, and the vertical tubes may be used as the down pipes. In the conventional tubular structures of that type, each vertical tube and each horizontal tube connected thereto are located in one and the same plane. However, in many instances, a structure of this conventional kind has the drawback, that it cannot be satisfactorily adapted to the requirements of the differ 'ent forms and types of the heating surfaces.

The invention further aims to provide a tubular boiler framework in which all or at least some of the connected tubes crosswise overlap each other and are passed eccentrically through each other so that the axes of the nited Patent O eccentrically connected tubes are located in different planes.

In a framework according to the invention, the length of the so connected tubes may be extended beyond the point of connection and the extensions may be closed by a removable means whereby an upper extension of a vertical tube may serve for the attachment of connecting conduits or as preseparator of water carried along by the generated steam, and a lower extension may be used as a mud collector.

The invention further contemplates an arrangement of the lower horizontal tubes closer to the furnace space than the eccentrically connected vertical framework tubes and even approximately on the level of the grate in order to use them as' grate-cooling tubes whereas the vertical tubes being more remote from the furnace are better protected against being heated.

Further objects and details of the invention will be apparent from the description given hereinafter and the accompanying drawing illustrating an embodiment thereof by way of example. In the drawing Fig. 1 is a longitudinal cross-section along line 11 of-Fig. 2 of'a boiler according to the invention,

Fig.2 is a cross-section along line 22 of Fig. 1,

Figs. 3 to 5 are partial cross-sections along lines 3-3, 4-4, and 55 of Fig. l, on a larger scale, and

Fig. 6 is a top plan view of another kind of tube-connection for use in a boiler framework according to the invention.

Referring now to the drawing, the boiler illustrated in Figs. 1 and 2 is shown without the conventional brickwork and insulation except for parts 10 and 11 of the ice.

other kinds of boilers, as e. g. in a hot water boiler.

The framework of the boiler comprises the four vertical tubes of which the tubes 12, 13 and 14 are visible .in Figs. 1 and 2. The vertical tubes are connected in their lower portions by horizontal tubes 15, 16, 17land 18, and in their upper portions by horizontal tubes. 19, 20, 21 and 22. A steam-water drum 43 .is provided and so arranged that it is part of the boiler frame struc ture, the corner tubes 12 and the longitudinal tubes .21 and 22 being rigidly connected to the drum. A set of tubes 23, forming a lateral heating surface on the one side of the boiler is connected to the tubes 17 and 21. Similarly another set of tubes 24 forming a lateral heating surface on the other side is connected to the tubes-18 and 22. Rear wall tubes 25 are connected between the horizontal tubes 16 and 20 of the framework, and other bundles, such as the bundle 25a of tubes may be provided in any suitable and conventional arrangement as parts of the heating surface.

In a boiler of the type illustrated, operating as a steam generator, each of'the elements of the framework has an additional function, i. e. the corner tubes 12 to 14 are down pipes, horizontal tubes 15 to 18 are distributors,

tubes 19 to 22 are collector tubes, so that water will circulate through the entire structure including the drum 43.

The furnace :work.

According to the invention the connection. of at least some of the tubular elements of the framework is such that the axes of the connected elements cross one another, and the one element penetrates or is passed through the other element eccentrical ly with respect to the axis of the latter. In this manner, a horizontal tube may be located at least partially e. g. in front or in the rear of a corner tube, or in any other relative arrangement as may be desirable in consideration of the heating conditions and the stresses of the framework caused thereby. Thus, the lower horizontal tube 15 is eccentrically connected to with the grate 26 is located inside the framethe front corner tubes 12, and tubes 17 and 18 are simiof the framework. Fig. 3 clearly shows the connection of the corner tube 12 with the horizontal distributor tube 17. The axis b-b of the distributor 17 crosses the axis a of the corner tube 12, and, in the illustrated embodiment the axes are so far spaced'from one another, that the 'tubes penetrate each other with about half of their crosssections. This claw-like interengagement of the tubes strengthens the frame structure quite considerably. The tube 17 projects with a free end portion 27 from the con nection with tube 12 and is closed by a removable plug .28. LAnother removable closure, i. e. a blank flange 29; is shown in-Figr-l at the other end of the tube 17. "Both closures may be removed when the tube is to be cleaned. Owing to the eccentric connection, corner tube 12 can be located closer to the sheet metal jacket 30 of the boiler than otherwise possible so that the connecting piece 31 between the tube 12 and the corner bar 32 can be correspondingly shorter. The connections of the tubes 15 and 18 to the corner tubes 12 are similar to those of tube 17 and do not require an additional explanation. The

ter particular difiiculties.

connection according to the invention ofiers the addition-- a1 advantage, that as clearly shown in Fig. 2 the distributor tubes 17 and 18 can be arranged on the level of and close to the grate 26 so that they help to cool the glowing grate bars and to protect the boiler insulation against the intense heat while allowing fora location of the cor- .ner tubes more remote from the grate where they are not or only slightly heated.

Fig. 4 illustrates the connection of three tubes, viz. the rear corner tube 13, longitudinal tube 17 and transverse tube 16. In this case only the connection between the tubes 13 and 17 is eccentrical whereas the axes b-b of tube 17 and c--c of tube 16 intersect each other as they are located in one horizontal plane. Nevertheless,

.Fig. 4 clearly shows the protected position of the corner tube 13 in the rear of the .side wall tubes 23 and the rear wall tubes 25. An insulating piece 33 may be provided further to protect the corner tube.

In. the upper part of the furnace the protection of the vertical corner tubes from being heated does not encoun- Therefore, the position of the upper horizontal tubes in relation to the corner tubes can be selected as desired. In boilers with straight evaporator tubes, the upper horizontal tubes must be in the same plane as the lower horizontal tubes, i. e. on the side of the corner tubes adjacent the furnace. Where, however, bent evaporator tubes are used, it is preferable to connect the upper horizontal tubes to the. corner tubes on the sides remote from the furnace. In that event it is possible to connect the evaporator tubes with a bend to the upper horizontal tubes whereby the increased elasticity reduces the stresses in the framework.

Fig. 5, illustrates such a connection in a rear upper corner of the framework. In this corner, the axes of the horizontal tubes 20 and 23 intersect each other. The axis 1 of the vertical tube 13 intersects the axis d.d but crosses the axis e-e. Hence, whereas in Fig. 4 the vertical tube '13 is located on the outside of tube 17 with respect to the furnace, it is located on the inside of tube 21 in Fig. 5. This arrangement is preferred in the case of the lateral collector tubes as the side wall tubes 23 and 24 are bent at their upper ends 35 and 36, respectively, in order to provide for the mentioned higher elasticity where they connect with the collector tubes 21 and 22. Tube 13 need not be eccentrical with respect to the axis of the tube 20. It is in a well protected position which may be .still improved if a bafile is formed in front of the tube 13 e. g. by wings 37 and 38 of the adjacent ones of the side wall tubes 23 and rear wall tubes 25.

Another form of a tubular corner useful in corner tube boilers is shown in Fig. 6 where two tubes 40 and 41 are located in one plane and connected e. g. by welding to a quarter bend 42. The third tube 44 is at right angles to the plane of the other tubes and is passed at least partly through the bend 43 so that the axis g of tube 44 is eccentrical with respect to the axis 11 of the bend.

Figs. 1 and 2 also show that the vertical corner tubes 12, 13, .14, extend further downward beyond the distributor tubes 16, 17 and 18 than necessary to form the connection. Thereby the lower ends of the corner tubes can be utilized as mud collectors. The mud can be removed from time to time by means of the pipes 45 and the mud valve 46.

An upward extension of a corner tube may also be advantageously utilized. Thus, the upper ends of the tubes 13 and 14 are extended beyond their connections with the tubes 20, 21 and 22 on the-mean water level in drum 43, and connecting pipes 47 are jointed to, these upper ends so as to conduct separated steam directly to the steam space of drum 43.

it will be apparent to those skilled in the art that many alterations and modifications of the structure illustrated and described can be made without departure from the spirit and essence of my invention which for that reason shall not be limited but by the scope of the appended claims.

I claim:

1. A boiler construction comprising a rectangular upstanding wall structure of insulation material enclosing a combustion space, downcomer tubes extending vertically at the several corners of said structure, at least one pair of collector tubes extending horizontally along opposite sides of the combustion space at the upper end thereof, the collector tubes being connected to and being in communication with at least two of said downcomer tubes, respectively, located at said opposite sides of the space, the axes of said collector tubes being olfset horizontally from the axes of the downcomer tubes to which they are respectively connected, in a direction outwardly from the combustion space, at least one pair of distributor tubes extending horizontally along said sides of the combustion space at the lower end thereof, the distributor tubes being connected to and being in communication with the downcomer tubes to which the collector tubes are connected, the axes of the distributor tubes being ofiset horizontally from the axes of the downcomer tubes to which they are connected, in a direction inwardly of the combustion space, said distributor tubes being at least partially exposed within the combustion space and the collector tubes being disposed outwardly from said combustion space, and banks of evaporator tubes having portions extending vertically along said opposite sides of the combustion spacein positions exposed to the eifects of combustion occurring within said space, the evaporator tubes of the respective banks having their lower ends connected to said inwardly ofi'set distributor tubes and having at their upper ends. lateral extensions projecting from the vertical portions outwardly of the combustion space and connected to the outwardly offset collector tubes, thus to allow expansion of the vertical portions in an axial direction under the effects of hot products of combustion impinging thereagainst within the combustion space.

2. A boiler as in claim 1 wherein the axes of the distributor and collector tubes are tangential to the circumferenres of the downcomer tubes to which they are connected, and the axes of the downcomer tubes are in turn tangential to the circumferences of said distributor and collector tubes.

3. A boiler construction as in claim 1. wherein said downcorner and collector tubes are wholly enclosed in the walls of said structure, the distributor tubes and the vertical portions of the evaporator tubes being embedded for approximately half: their circumferences" in the inner surfaces of said walls.

References Cited in the file ofv this patent UNITED STATES PATENTS 439,684 Pratt Nov. 4, 1890 487,620 Herbert Dec. 6, 1892 1,639,737 Kelly Aug. 23, 1927 1,998,828 Armacost Apr. 23,. 1935 FOREIGN PATENTS 494,237 Belgium Mar.31, 1950 r-T g

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