US3204610A - Intertube burner - Google Patents

Description

p 7, 1965 T. s. VOORHEIS ETAL 3,204,610

INTERTUBE BURNER 3 Sheets-Sheet 1 Filed July 9, 1963 INVENTORS VQORHEIS HUDSON ERT F. BRUNS T ATTORNEYS Sept 1965 T. s. VOORHEIS ETAL 3,204,610

INTERTUBE BURNER 3 Sheets-Sheet 2 Filed July 9, 1963 INVENTORS PLE S. VOORHEIS IEL H. HUDSON ERT F. BRUNS ATTORN EYS Sept. 7, 1965 T. s. VOORHEIS ETAL INTERTUBE BURNER 3 Sheets-Sheet 3 Filed July 9, 1963 ATTORNEYS United States Patent 3,204,610 INTERTUISE BURNER Temple S. Voorheis, Palo Alto, Daniel H. Hudson, San Lorenzo, and Robert F. Bruns, San Leandro, Califl, assignors to Coen Co., San Francisco, Calif., a corporation of California Filed July 9, 1963, Ser. No. 2%,752 9 Claims. (Cl. 122-235) This invention relates generally to the art of boiler furnace construction and more specifically relates to that type of construction known as intertube gas-fired boiler furnace system.

Until fairly recently, most industrial boilers that have been fired with gas or oil were arranged so that the burner introduced the fuel and air into the furnace through a circular refractory throat or opening formed in the side of the furnace. In such a type of construction, it is necessary to bendably deform or curve the boiler pipes around the circular throat opening so as not to obstruct the emission of the fuel and air directly into the furnace for ignition and combustion therein. It has been found that in many types of installations, it is a diflicult and expensive process to properly bend and curve the boiler pipes around the refractory throat. As a consequence of this latter named difliculty, it has been proposed in more recent times, both in reference to constructing new boiler installations as well as in converting old boilers to the use of more modern and up-to-date burner equipment to form a rectangular opening in the furnace wall and to run the boiler water tubes vertically across the opening in parallel spaced relation.

In this type of construction, it has been conventional practice to mount on the boiler tubes that span the furnace opening gas jets which operate to emit jets of gas into the furnace proper in conjunction with air introduced simultaneously from a windbox or blower through the spaces defined between the spaced apart boiler tubes. The gas jets that are mounted on the boiler tubes are commonly referred to in the art as gas shoes. In effect, each gas shoe consists of a hollow vertical manifold tube that is mechanically mounted to the boiler tubes which manifold tube is provided with a series of gas jet openings displaced and oriented in such way as to inject streams of raw gas or other fuel at desired angles of emission into the furnace in such manner as to impringe upon and be entrained by the streams of air flowing through the spaces between the boiler tubes. At the point where the gas streams and air mix, combustion occurs within the boiler. Although this type of intertube gas burner system as developed to date permits the boiler tubes to span the openings into the furnace and thereby eliminates the necessity of bending or curving the tubes around a circular throat opening, such system has been found to involve certain other difficulties and problems which the present invention is specifically designed to alleviate or minimize.

More specifically, in the conventional type of intertube gas-fired system above mentioned, all of the air that flows through the vertical passages defined by the spacings between the boiler pipes is moving in a straight line path parallel to the longitudinal axis of the furnace. There is no provision for swirling or distributing the air or imparting to it any other vector of movement other than its straight line path of flow from one end of the furnace to the other. When the air stream mixes with the gas and combustion occurs, the expansion of the gas caused by the heat and combustion added to the velocity of the incoming air results in a high temperature velocity movement of burning gases impinging upon a concentrated area on the opposite side of the boiler. This in turn results in an uneven concentration of heat in the boiler Patented Sept. 7, 1965 furnace and, at the end where the heat concentration is highest, the boiler tubes may be subjected to abnormal destructive forces.

The particular embodiment of the present invention which is shown in the drawings and which will be described more fully hereinafter comprises in combination with a rectangular furnace opening a plurality of spaced apart parallel boiler tubes spanning said opening; the spaces between said tubes defining vertical passages for flow of combustion air into said furnace; gas jet means mounted adjacent at least some of the tubes for emitting jets of gas into said chamber at an angle intersecting the air flowing through said passages; air deflector means mounted in at least some of said passages; said air dcflector means in each passage comprising a plurality of air vanes mounted at varying angles in reference to horizontal to direct components of the air stream at various angles. The flame pattern is thus distributed uniformly over the interior of the boiler; consequently, the longevity of the boiler tubes and refractory lining is increased, and heat absorption by the boiler tubes in the furnace is more uniform.

A feature and advantage of the present invention resides in orienting the vanes in one intertube space so that air is directed generally upwardly while the vanes in intertube spaces on either side of the first named space are oriented to direct the air generally downwardly, thereby to provide a scrubbing action between air streams entering through adjacent intertube spaces. As a consequence of such scrubbing action, turbulence occurs to intermix intimately air and fuel.

The objects, features and advantage of this invention will be apparent upon referring to the following specification and attached drawings in which:

FIGURE 1 is a cross-sectional plan view showing my improved intertube burner mounted on a water tube boiler;

FIGURE 2 is an enlarged cross-sectional elevation view of an air distributor of my invention taken substantially along line 2 2 of FIGURE 1;

FIGURE 3 is an enlarged front view of my air distributor taken substantially along line 33 of FIGURE 1;

FIGURE 4 is a cross-sectional view of a modification of my air distributor;

FIGURE 5 is a schematic representation of a flame pattern in a typical water tube boiler;

FIGURE 6 is a schematic representation of a flame pattern produced by use of the prensent invention; and

FIGURE 7 is a cross-sectional view of a. fuel manifold of the present invention.

Referring more particularly to the drawings, reference numeral 12 indicates a refractory lining of a conventional water tube boiler 13 which lining is structurally supported by an outer shell 14. Alongthe interior surface of refr-actory lining 12 is disposed a plurality of water tubes 16 that extend in a conventional manner along the interior boiler wall. Water is fed through water tubes 15 from a source not shown and heat applied to the exterior surface of the water tubes converts the water therein to steam.

Boiler 13 is provided with an opening 18 in a side wall thereof through refractory lining 12 and shell 14 which opening communicates with the boiler interior. Although opening 18 can be any convenient shape, provision of a rectangular opening makes easier the construction and installation of the burner. It is to be understood that opening 18 can be provided in the boiler wall when the boiler is initially constructed or that it can be cut in the wall at any later time, such as during repair. Extending from the sides of opening 18 are support members 20 that support on their outer ends a conventional air duct 22 into which air is moved from a conventional fan or blower shown schematically at 24. Duct 22 substantially covers the entire opening 18 to permit movement of air into the furnace throughout the entire area of the opening.

Water tubes 16 span opening 18 in parallel spaced apart relation and, in accordance with conventional water tube boiler technology, are aligned vertically. For convenience of description the spanning water tubes are divided into two alternate groups; tubes 16a forming one group, and tubes 16b forming the other group. Each water tube 16a has associated therewith a fuel manifold or show 26 which extends substantially throughout the entire span of a tube 16a and is provided with an arcuate concavity 28 that nests with the exterior surface of water tubes 16a. Each manifold 26 has a hollow interior forming one or more fuel conduits 30 therein. Adjacent concave portion 28 the manifold is provided with backwardly sloping walls 32 which have formed therein a plurality of jet openings 34 for injecting fuel into the boiler interior through spaces between adjacent water tubes. Attached to each manifold 26 in fluid communication with conduits 30 is a pipe 36 that is connected to a suitable fuel header, not shown, for effecting delivery of fuel to jet openings 34. Each side extremity of manifold 26 is provided with a mounting flange 37 and with two or more openings 38 for receiving a mounting bolt 39 which is welded, or otherwise suitably affixed, to water tube 16a.

Each tube 16a adjacent the side edges of opening 18 is provided with a manifold 30' having only one row of fuel jets 34' as well as only one mounting flange 37'. On the opposite side of manifold 30 is a protrusion 40 that is received by a ridge 42 formed in opening 18.

To each tube 16b, between tubes 16a with which manifolds 26 are associated, is attached an air distributor indicated generally at 44. Air distributor 4d (FIGURE 3) has an elongate central portion 46 which defines several mounting holes 48. A threaded fastener 50 extends through mounting holes 48 into a suitable clamp 52 that is aflixed to each alternate water tube 16b. Extending outwardly from opposite sides of central portion 46 are vane assemblies 53a and 53b each of which has a plurality of vanes 54. Vanes 54 are adapted at their outer extremities 55 to bear against mounting flanges 37 so as to aid in securing manifolds 26 in nesting relationship with water tubes 16a. Each vane assembly 53a, 53b is formed on the inner edge thereof with apertured flanges 56 to effect attachment to central portion 46.

Each vane 54 is formed with a generally flat upper surface 57 and a generally flat lower surface 53. Opposing surfaces of adjacent vanes are substantially parallel with one another. Between the upper surface 57 of one vane, for example vane 54a of FIGURE 2, and the lowe surface of the vane thereabove, for example vane 54b of FIGURE 2, an air passage 60 is formed. Because vane assemblies 53a and 53b of the specific air distributor of FIGURES 2 and 3 are oppositely mounted on central portion 46, the device is particularly suitable for installation in an opening 18 that is positioned near the vertical center of the boiler wall. The air moving through distributor 4,4 is distributed upwardly by vane assembly 53a and downwardly by vane assembly 53b. The air streams will also diverge horizontally in the furnace interior as a consequence of which the upwardly moving stream through vane assembly 53a will encounter the downwardly moving stream through vane assembly 5312. Such encounter creates a scrubbing action between the two streams as a result of which substantial turbulence occurs. Turbulent air flow promotes admixture of air with fuel injected from fuel jets 34.

In such installation the lowermost air passage 6% of vane assembly 53a and the uppermost air passage 60a of vane assembly 53b are generally normal to the plane defined by water tubes 16a16b, and each successive air passage above lower passage 60a and below passage 6% is inclined at a decreasing angle relative to the water tube plane. By way of example in one installation of the present invention air passage 60b is aligned at an angle of approximately relative to the plane of the water tubes 16a and air passage 66c adjacent and above air passage 60b is aligned at an angle of 66 relative to the water tube plane. Air passages below passage 6% are aligned at angles progressively greater than 70, air passages above passage 600 are aligned at angles progressively smaller than 66. It will be obvious that such alignment of air passages dill) and 60c is obtained by a corresponding angular position of the opposing vane surfaces forming the respective air passages. The angular position of each air passage 60 is progressively reduced until at the top of vane assembly 53:: on air distributor 44 an air passage 60d is aligned at an angle of about 30 relative to the plane of the water tubes. It is to be understood that the specific angular values given above are exemplary, and that different angular values can be provided to suit individual burner installations. Additionally, the vane assembly can both be mounted to direct moving air upwardly or to direct the air downwardly.

In operation fuel is supplied through pipes 36 to conduits 3%) in manifolds 26; the fuel is thus injected into the boiler furnace interior through fuel jet openings 34. Actuation of blower 24 moves air through duct 22 into the boiler furnace interior through spaces between adjacent spanning water tubes. The direction of movement is indicated by an arrow 62 in FIGURE 2. As the moving air impinges upon the upper surfaces 57 of vanes 54 in vane assembly 53a, the air is deflected upwardly by amounts proportional to the angular alignment of air passages 60. Air moving through vane assembly 53b is directed downwardly. Moving air so distributed will entrain fuel ejected from jet openings 34 and upon ignition, by suitable means not shown, a uniform flame pattern such as depicted in FIGURE 6 will result. As contrasted with the flame pattern shown in FIGURE 5, which is the flame pattern obtained without interposition of air distributors 44 in the intertube spaces, the flame pattern afforded by the present invention is superior, in that more uniform heat distribution is obtained and concentrations of heat on refractory linings 12 or boiler tubes on the opposite furnace side wall are eliminated.

A modification of the present invention particularly suitable for installations wherein a boiler wall opening is formed intermediate the vertical extremities of the wall is shown in FIGURE 4. An air deflector 70 is shown having a vane 73 intermediate the ends thereof that has an upper surface 74 and a lower surface 76 that are generally normal to the plane in which the water tubes reside. In parallel opposition with upper surface 74 a lower surface 76a of a vane 73a is provided to form an air passage 80. In parallel opposition with lower surface 76 and upper surface 74b of a vane 73b is provided to form an air passage 80b. Successive air passages 80 formed above and below vane 73 are aligned at progressively decreasing angles with respect to the water tube plane.

The operation of a burner provided with modified air deflector 7G is substantially identical with the mode of operation described above. Air moving through the deflector in a direction indicated by arrow 82 is deflected by the lower surfaces of the vanes below vane 73 and by the upper surfaces of the vanes above vane 73. Air thus deflected will form a uniform flame pattern having the advantages referred to above.

While two embodiments of the invention have been shown and described, it will be apparent that other adaptations and modifications can be made without departing from the true scope of the invention.

What is claimed is:

1. In a water tube boiler furnace of the type having a fiat wall with parallel spaced apart water tubes extending along the wall interior of the boiler furnace, an improved intertube burner comprising: a portion of said wall forming an opening therethrough communicating with the interior of the boiler furnace, a plurality of parallel spaced apart Water tube-s spanning said opening; a gas manifold associated with each alternate tube, said manifold having a hollow central portion and being formed with a plurality of jet openings in fuel communication with the hollow portion, said jet openings being formed on opposite sides of said tube and being adapted to inject fuel between adjacent tubes into the boiler furnace interior, an air deflector associated with each alternate tube, said air deflectors having a plurality of vanes disposed in an air flow path between adjacent tubes, said vanes being angularly oriented relative one another and relative the longitudinal axis of said tubes to eifect uniform air distribution obliquely with respect to perpendicular of the longitudinal axis of the tubes and throughout the boiler furnace interior.

2. In a water tube boiler furnace of the type having a Wall formed with an opening, a plurality of parallel spaced apart tubes spanning said opening, a plurality of jets for injecting fuel to the interior of said boiler furnace through spaces between said tubes, and means for moving air into the interior of said boiler through spaces between said tubes; means for distributing the moving air comprising: an elongate central portion, means for mounting said central portion onto one of said tubes longitudinally thereof, a plurality of fixed vanes extending from said central portion into the intertube space, each said vane having first and second flat surfaces, said surfaces being aligned so that the second surface of one vane is disposed substantially parallel with thefirst sur face of the vane adjacent thereto, each pair of said parallel vane surfaces defining a dilferent angle relative to the direction of air movement through said wall opening so that a uniform flame pattern is established in the boiler.

3. In a water tube boiler of the type having a wall defining an opening and a plurality of parallel spaced apart Water tubes spanning said opening, alternate said tubes forming first and second tube groups, an improved burner for said boiler comprising a plurality of elongate fuel manifolds each being formed with a concavity for nesting relation with a tube in said first tube group, means for securing each said manifold to the tube related thereto, each said manifold having a plurality of jets for injecting fuel into said boiler through spaces between adjacent tubes, means disposed between spaces between adjacent tubes for distributing air moving through said wall opening, and means for mounting said air distributing means to the tubes of said second tube group, said air distributing means having an elongate central portion, a plurality of vanes fixedly secured to said central portion for deflecting the moving air from a straight line path and obliquely with respect to perpendicular of the longitudinal axis of the tubes, said vanes extending from said central portion to said manifold.

4. In combination with a boiler furnace of the class that includes a vertical wall formed with a burner opening therein and a plurality of co-planar parallel spaced apart Water tubes vertically spanning said opening, an improved air distributor comprising an elongate central portion, means for mounting said central portion to one of said water tubes, a plurality of vanes fixedly extending from opposite sides of said central portion into spaces between adjacent Water tubes, adjacent said vanes having mutually opposing surfaces forming air passages into the interior of said boiler furnace, said vane surfaces being oriented so that each said air passage is formed at a different angle relative to the plane of said Water tubes for distributing lowest said air passage is formed generally normal to the plane of said water tubes and each succeeding air passage is formed at a successively smaller upwardly inclined angle relative said plane.

6. An air distributor according to claim 4 wherein two adjacent air passages intermediate the ends of said central portion are disposed generally normal to the plane of said water tubes, each air passage above said adjacent air passages is formed at a successively smaller upwardly inclined angle relative said plane and each air passage below said adjacent air passages is formed at a successively smaller downwardly inclined angle relative said plane.

7. An air distributor according to claim 4 wherein the lowest said air passage formed on one side of said central portion is oriented generally normal to the plane of said water tubes and each succeeding air passage is formed at a successively smaller upwardly inclined angle relative said plane, and wherein the highest said air passage formed on the other side of said central portion is oriented generally normal to the plane of said water tubes and each succeeding air passage is formed at a successively smaller downwardly inclined angle relative said plane, whereby air entering opposite sides of said central portion is deflected upwardly and downwardly respectively, thereby to afford scrubbing action between the two deflected air streams.

8. In combination with a boiler furnace of the class that includes a vertical Wall having a burner opening therein and a plurality of co-planar parallel spaced apart water tubes vertically spanning said opening, an improved air distributor comprising an elongate central portion, means for mounting said central portion to one of said water tubes, a plurality of vanes fixedly extending from opposite sides of said central portion into spaces between adjacent water tubes, each said vane having an upper and a lower surface, the upper surface of one vane being in confronting relation to the lower surface of the vane adjacent thereto, a surface of the said vane at a vertical extremity of said opening and the confronting surface of the adjacent vane being substantially normal to the plane of said spanning tubes, each confronting pair of surfaces vertically inwardly of said extreme vane being disposed at a decreasing angle relative said plane, w ereby air moving through said air distributing means is uniformly distributed Within said boiler furnace.

9. In combination with a boiler of the class that includes a vertical wall having a burner opening therein and a plurality of co-planar parallel spaced apart water tubes vertcially spanning said opening, an improved air distributor comprising an elongate central portion, means for mounting said central portion to one of said water tubes, a plurality of vanes fixedly extending from opposite sides of said central tubes, one of said vanes intermediate the ends of said central portion being formed with an upper and a lower surface generally normal to the plane of said water tube, the vane next above said intermediate vane having a lower surface in substantial parallel opposition to the upper surface of said intermediate vane, the vane next above said intermediate vane having an upper surface at an upwardly sloping angle relative the plane of said water tubes, each succeeding vane having a lower surface in parallel opposition to the upper surface of the vane therebelow and an upper surface at an upwardly sloping angle relative the plane of said Water tubes less the angle of the lower surface thereof; the vane next below said intermediate vane having an upper surface in substantial parallel opposition to the lower surface of said intermediate vane, the vane next below said intermediate vane having a lower surface at a downwardly sloping angle relative the plane of said water tubes, each succeeding vane havportion into spaces between adjacent Water 7 ing an upper surface in parallel opposition to the lower surface of the vane thereabove and a lower surface at a downwardly sloping angle relative the plane of said water tubes less the angle of the upper surface thereof, whereby air moving into said boiler through said distributor is distributed upwardly by the vanes above said intermediate vane and is distributed downwardly by the vanes below said intermediate vane.

References Cited by the Examiner UNITED STATES PATENTS 2,229,068 1/41 Frisch 222--23S 3 Leach 122235 Reed 122-235 Smith et a1. 122-235 Barton 122-235 Examiners.

Claims (1)

1. IN A WATER TUBE BOILER FURNACE OF THE TYPE HAVING A FLAT WALL WITH PARALLEL SPACED APART WATER TUBES EXTENDING ALONG THE WALL INTERIOR OF THE BOILER FURNACE, AN IMPROVED INTERTUBE BURNER COMPRISING: A PORTION OF SAID WALL FORMING AN OPENING THERETHROUGH COMMUNICATINGWITH THE INTERIOR OF THE BOILER FURNACE, A PLURALITY OF PARALLEL SPACED APART WATER TUBES SPANNING SAID OPENING; A GAS MANIFOLD ASSOCIATED WITH EACH ALTERNATE TUBE, SAID MANIFOLD HAVING A HOLLOW CENTRAL PORTION AND BEING FORMED WITH A PLURALITY OF JET OPENINGS IN FUEL COMMUNICATION WITH THE HOLLOW PORTION, SAID JET OPENINGS BEING FORMED ON OPPOSITE SIDES OF SAID TUBE AND BEING ADAPTED TO INJECT FUEL BETWEEN ADJACENT TUBES INTO THE BOILER FURNACE INTERIOR, AN AIR DEFLECTOR ASSOCIATED WITH EACH ALTERNATE TUBE, SAID AIR DEFLECTORS HAVING A PLURALITY OF VANES DISPOSED IN AN AIR FLOW PATH BETWEEN ADJACENT TUBES, SAID VANES BEING ANGULARLY ORIENTED RELATIVE ONE ANOTHER AND RELATIVE THE LONGITUDINAL AXIS OF SAID TUBES TO EFFECT UNIFORM AIR DISTRIBUTION OBLIQUELY WITH RESPECT TO PERPENDICULAR OF THE LONGITUDINAL AXIS OF THE TUBES AND THROUGHOUT THE BOILER FURNACE INTERIOR.

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