US2154177A - Fluid heater - Google Patents

Description

Agra 11, 1939. I v M RAY 2,154,177

FLUID HEATER Filed June 19, 1935 2 Sheets-Sheet 1 INVENTOR, 5* Va qzll WMoray V. W. MORAY FLUID HEATER Filed June 19, 1935 April 11, 1939.,

2 Sheets-Sheet 2 INVENTOR,

III/I/III/I/IIIIII 4 Patented Apr: ll, 1939 UNITED STATES PATENT. OFFICE FLUID HEATER Virgil w. Moray, New York, N. Y., assignor a Akwa Heaters, Inc., New York, N. Y., a corporation of New York Application June 1a, 1935, Serial No. 27,281- 15 Claims. (01. lea-am This invention relates to fluid heaters and throughout its entire length so that sagging of more particularly pertains to steam boilers and the coil is prevented. The support is also readily auxiliary fluid heating means combined thereadjustable from outside of the boiler so that the with. More specifically, the invention relates to coil may be maintaineddn the desired spaced auxiliary water heating coils for standard and relationship to the boiler tubes.

other types of steam boilers. The invention further provides a multi-com- Heretofore auxiliary water heating coils for partment fluid heating coil head which may readsteam boilers have generally been installed by ily be converted to provide for a single pass or laying the coils on top of the boiler tubes and. a plurality of passes through the coil 01 the m by bolting the coil head to the boiler tube sheet. fluid to be heated, without the use of perforated In order to prevent leakage between the steam partitions or partition plugs or the like and the and water space of the boiler and the smoke attendant danger of leakagei box or combustion chamber, it has been neces- Other features and advantages of the invensary to employ a relatively wide flange on the tion will be perceived from the iollowingdescriphead and a wide gasket or to use a narrow flange -tion considered in connection with the accomi5 and gasket with a large number of bolts. This panying drawings forming a part thereof and in type of connection is very rigid and it is diflicult, which: it not impossible, to prevent leakage at all tem- Fig. 1 is a partial longitudinal sectional view peratures during operation and when the boilof a tire tube steam boiler having a longitudinally er is out of service. Additionally, the coil head is disposedauxiliary heating coil embodying, and 20 subjected to' corrosionas a result of the con---- supported in accordance with, the invention: tact of the combustion gases with the metal of Flg. 2 is a sectional view on an enlargedscale, the coil head. Since the tubes of the coils are taken on line 2-2 of Fig. 15 normally of copper or copper alloy, electrolytic .Fig. 3 is a sectional view taken on line H '5 action is set up at all points of contact between of Fig. 2; as the copper coils and the steel boiler tubes. This Fig. 4 is a sectional view taken on line 4-4 of electrolytic action materially reduces the life of Fig. 2; J

the boiler tubes, in some instances as much as Fig. 5 is .a sectional view taken on line 55 oi one-half. A further disadvantage is. the ex- Fig. 4; I r treme diiliculty of replacing detective boiler tubes Fig. 6 is a partial diagrammatic sectional view 30 without damaging the coils resting upon them. showing a coil mounted in a fire tube boiler hav- The present invention overcomes the aforeing horizontally inclined boiler tubes; said disadvantages and others, and provides an Fig. 7 is a partial transverse sectional view of elastic or resilient means for sealing and secura tire tube steam boiler having a transversely dis- 3.) ing the coil heads against theboiler tube shee posed auxiliary heating'coil supported in acthe securing and sealing force exerted being sutcordance with the invention, and ilcient to hold'the coil head tightly against the Fig. 8 is a sectional view of a detail showing tube sheet at all times with-suillcient force to one manner of connecting the supporting chain prevent leakage and with suflicient elasticity so to the coil spacer plates. 40 that expansion and contraction of the head is 1 e charactersoi reference refer to the same 4|) permitted without leakage even after rather seor similar parts throughout the several views.

vere contraction of the head as when the boiler The invention will be disclosed in connection is out of operation. The coil head is also prowith aflre tube boiler and although e invention tected against the corrosive action of the combus is particularly useful in boilers of t type, it

" .3 tion gases by enclosing the headin a casing and will be understood that it is equally applicable 5 means are provided for ventil tion and cooling of to water tube boilers.

the casing. In the form of the invention dis- Rcierring'to the drawings, reierence characclosed herein, the casing and coil head tel ll designates the shell of a iire tube boiler .means are combined, as a result of which great ,havinga pair or spaced tube sheets ll (only one so compactnessof the entire coil head; assembly is of which is shown), between which extends a obtained. bank of tire "tubes II. The {rout end oi the -shell Theinvention further provides means for sup- I0 is closed by a cover I! 'whichforms with the t I porting the coils above the boiler. tubesand entubesheet II, a smoke box II. In the ionn oitirely out of contact therewith. The character the invention illustrated particularly in Figs. 1,

as of the support is suchthat the coil is supported- 2 and 3, a water heating coil is longitially parallel to the boiler tubes l2. Referring to Fig. 1, the water heating coil consists of a plurality of loop tubes l5 which are connected to a coil head l6. The tubes extend through an opening H in the tube sheet ll'which is large enough so that the copper tubes of the coil do not come in contact with the steel tube sheet. The coil head I6 is disposed in the smoke box l4. The tubes l5 are suspended above the boiler tubes l2 out of contact therewith in accordance with the invention, to avoid any electrolytic action due to contact of the copper tubes 'of the coils with the steel tubes of the boiler. The tubes l5 of the heating coil pass through spaced tube holes in a plurality of spaced coil spacer plates l8 so that the tubes l5 may be supported throughout their entire lengths. The number and disposition of these spacer plates may be varied to provide the support desired for the tubes of the coil. A chain l9 having its ends connected to the outermost spacer plates l8 of the coil, passes through the opening in an I-bolt 20 which is supported from the shell ll] of the boiler. Smaller chains 19' and I9 connect the intermediate spacer plates l8and chain l9. The

I-bolt supporting means includes a nipple 2|.

the lower end of which extends through the shell III of the boiler and which is welded as indicated at 22, or otherwise secured to the shell.

A steel disc 23 having a diameter substantially equal to the outside diameter of the nipple 2| rests upon the upper end of the nipple. The threaded upper end-of theI-bolt 20 extends through a central aperture in the disc 23 and a nut 24 threaded on the end of the I-bolt bears upon the steel disc and supports the I-bolt therefrom. A cap 25 having sufficient interior volume to house the upper end of the I-bolt is threaded on the upper end of the nipple. With this arrangement it will be perceived that the heating coil is supported at a plurality of points 'and is suspended from a single point from the boiler shell. The distance the coil is suspended above the boiler tubes l2 may be readily varied by an adjustment of the nut 24 on the indicated, and serves not only to protect thehead but also forms part of the means for securing the head to the tube sheet I l. The upper and lower walls 21 and 28 respectively of the casing 26 are provided with registering circular apertures and recesses, which receive cylindrical pins 29. A plurality of wedging members 36 engage spaced central portions of the pins 29' and the outer wall 3| of the head l6, andwedge the head against the tube sheet ll. gasket 32 is interposed between the head and the tube sheet to prevent leakage. In the form of the invention shown, the pins 29 are arranged to provide wedge contacting surfaces which may be disposed at varying distances from the tube sheet II, in order to provide flexibility in the securingof the head to the tube sheet to provide accommodation for manufacturing variations in the head and the casing. The pins 29 have spaced wedge-engaging sections 33 which A suitable are rectangular in transverse cross-sectiont Each of the wedge contacting surfaces 34 is disposed at a different radial distance from the axis of the pin. For example, one of the surfaces 34 may be disposed at the desired radial distance from the axis of the pin and the other .surface may be disposed respectively at radial distances which progressively increase by of an inch. In other words, one of the wedge contacting surfaces 34 may be disposedat the desired distance from the axis of the pin 29 with the surface 34 disposed normally to an axial plane of the pin and with each of. the other wedge-contacting surfaces 34a, 34b and 340 disposed at radial distances which are of an inch greater than the distance the next preceding surface is disposed. These surfaces 34 may, of course, be disposed as desired with respect to distance from theaxis and the number there- 'of may be varied as desired. In the form shown,

two pins 29 are utilized and normally this num-' her will suffice to adequately secure the header to the tube sheet, but any other number may be utilized. In some instances it may be found that a single pin having a plurality of cooperating wedges may be sufficient for the purpose. The wedges may readily be inserted from the open outer end of the head l6 which is closed by a cover 35. Cover 35 is forced into the casing 26 with sufficient tightness to prevent material leakage from the casing or it may be sealed with a suitable fire clay or cement.

If desired, plain circular pins without machined or otherwise prepared wedge-contacting surfaces may be employed, in which event the wedges will engage the cylindrical surfaces of the pins. Whetherplain pins or pins of the character of pins 29 are employed, the pinswill flex or spring outwardly with respect to the head I6 as indicated in the drawings, when the wedges are applied. This springing of the pins provides an elasticity or resiliency for the securing means which allows for expansion and contraction of the head so that the head is always held tightly against the tube sheet even when it is chilled and hence contracted. Leaks are thus prevented at all times whether the boiler is in or out of operation. With this arrangement, the necessity for the use of bolts and nuts and wldecoil head flanges is eliminated. The wedges exert a tremendous pressure against the coil head and press it with such force against the gasket and tube sheet that leakage is prevented.

With prior arrangements, the bolts holding the coil head to the tube sheet are often turned up so tightly inan effort to prevent or stop leakage that the bolts often are stripped and the prevention of leakage becomes impossible.

Fluid to beheated is supplied to the head l6 through an inlet pipe 36 and after flowing through the head and the coil tubes l5 wherein it is heated to the extent desired, it is conducted from the head through an outlet pipe 31. The inlet and outlet pipes mayconveniently be threaded into the head as shown. In the form of the invention illustrated, means are provided for circulating air around the head l6 to assist in preventing corrosion of the material of thehead. A pipe 38 having an inside diameter larger than the outside diameter of the inlet pipe 36 extends through the boiler shell "I and is welded into the side plate of the casing 26. The outer end'of the air conducting pipe 38 is opened to the atmosphere. A similar air conducting pipe 39 having its inner end welded into the upper 2,154,177 wall of the casing, 26 encloses the outlet fluid pipe 31 and extends through the upper part of the boiler shell. With this arrangement, air will be circulated through the casing 26 and over the coil head by thermo-syphon circulation, and thus cool the head and casing and prevent corrosion and destruction of the casing by the heat of the combustion gases. The air circulated through the casing will also carry away any moisture formed by the sweating of the cold water pipe.

Another feature of the invention is the. form of the lo'..'er wall 28 of the casing 26 which permits the heating coil Iii to be disposed inclose proximity to the boiler tubes l2 without actually being in contact therewith. With fire tube boilers this is of particular importance, since the boiler water level may be comparatively low and yet the tubes of the coil l5 may be completely submerged. To

this end the bottom plate 28 is wedge-shaped in longitudinal cross-section as shown in Fig. 1, with the smaller end of the plate disposed in contact with and welded to the tube sheet It. With this arrangement it will be seen that the coil head I6 may be disposed more closely adjacent the boiler tubes I2 than would'otherwise be possible.

The coil head I6 is arranged to provide a plurality of fluid compartments each of which is separated from the adjacent compartment or compartments by imperiorate walls so disposed that one or more of the walls may beperforated to the end that the headmay be converted to provide the number of fluid passes desired through the heating coil. In the form of head shown, the partitions are arranged to provide either a single pass or a two-pass coil. It will be understood however, that the invention may be utilized to provide a number of passes larger than two if desired.

This feature of the invention is disclosed in connection with a coil having fourteen single loop tubes or a coil having twenty-eight head connections. In some instances this number of tubes provides the greatest number which may be disposed in one head so far as auxiliary heating surface is concerned. However, the invention may also be applied to a larger or a smaller number of tubes than disclosed.

Referring particularly to Figs. 2 and 310! the drawings, the coil tubes I! have their ends connected into the rear wall of the head so that the ends of the tubes are arranged in horizontal rows which are superposed relatively closely adjacent each other, with the tubes in each row being disposed in vertical alignment with the tubes in all of the other rows. The arrangement of the tubes in each horizontal row is clearly indicated in Fig. 2. For convenience in description, the tubes are numberedin Fig. Ii with the inlet and outlet end of each tube being given the same number. For example, the outermost loop tube in the uppermost horizontal row'is numbered I and has both its inlet and outlet ends numbered l in Fig. 3. Disposed inwardly in a horizontal plane of tube I, is tube 2, and inwardly of tube 2, tube 3 is disposed. The same arrangement is followed with respect to the other horizontal tube rows, the tubes being numbered altogether from I to II. The space between the ends of tubes 3, 6, 9 and I2 is filled with vertically disposed loop tubes designated l3 and Il with the inlet and outlet ends of tube l3 disposed between the ends of tube 3 and the ends of tube l2 respectively. Tube I4 is disposed inside the tube i3 and has its inlet and outlet ends disposed respectively between the ends of tube 8 and tube 9.,

The head I8 shown in Figs. 2 and 3 is initially formed with three imperiorate partitions ll, 4! and 45. As viewed in Figs, 2 and 3, partition I:

is vertically disposed and has its inner end connected to the rear wall of the head between the I second and third vertical tube rows numbering from the right hand end of the head. Partition M is also vertically disposed.v parallel to partition 43, and has its rear end connected with or formed integrally with the rear wall of the head intermediate the fourth-and fifth vertical tube rows numbered from the right hand end of the head. ,Partition 45 is also vertically disposed but is positioned at right angles to the partition 4.4 with e which it is connected or integrally formed, and

is disposed parallel to the rear wall of the head and in spaced relationship thereto. The arrangement of these partitions is such that four head compartments are provided which are designated respectively A, B, C and D. To provide a twopass coil, the partition 44 is perforated as indicated, to provide a relatively large circular opening of about the diameter of. the inlet and outlet pipes 31 and 38. This may be. done by means of a suitable tool inserted through the opening in the side wall of the head which is closed by a flush plug 4|. With the partition apertured as described, the flow through the coil will be from the inlet pipe 36 into compartment A through the tubes connected to compartment A into transfer compartment B, thence into the inlet ends of the tubes of the second pass which are connected to the compartment B, into compartment C, through partition 44 into compartment D,'and out through pipe 31. Since there are fourteen loop tubes each having both ends connected to the head, it will be perceived that the compartments A and C should be arranged so that seven tubes have one end connected in each of these compartments. With the arrangement shown, there are normally eight-tubes connected in each of these compartments. The proper arrangement is provided by the use of pockets which end of tube 2 is connected to compartment C by means of a pocket 46 formed by a wall 41 which connects them with the compartment B. With this arrangement, the ends of seven tubes, that is,

tubes i, l, 5, I, 8, II and II are connected to the co'mpartmentA and these tubes discharge fluid into transfer compartment B. The fluid then enters'seven tubes numbered 2, l, 0, 9, II, II and I4 and these tubes discharge the fluid into compartment C after which the fluid flows into com-- partment D through the opening in partition M and mi: of the head through pipe 31.

If it is desired that the head be arranged to provide only a single pass for the fluid through the coil, partition ll is not perforated, but partitions ll and l! are both apertured by smtable tools which may be inserted through the inlet opening of the head prior to the attachment of the inlet pipe 3! and through the opening in the outer wall II which is closed by a plug 42 to provide openings which are substantially equal in flow area to the flow areas of the inlet and outlet pipes. With the partitions I and lb apertured serve to connect the excess number of tubes to the proper compartment. As shown, the inlet,

and the partition 44 remaining imperforate, the flow will be from the inlet pipe 36 into both compartments A and C and through pipes I to It inclusive into the transfer compartment B, through the opening in partition 45 into compartment D, and thence through outlet pipe 31.

With this arrangement of the head of the heat ing coil, it will be seen that a standard form of head may be provided which may be readily altered or converted to provide asingle pass or a two-pass flow of fluid through the coil. viously mentioned, although the head disclosed may be converted only to either a single pass or two-pass header, nevertheless it will be understood that the invention may be applied also to provide passes other than single or two passes if desired.

As shown in Fig. 6, the heating coil may be arranged for installation with a boiler in which the boiler tubes l2 are horizontally inclined. The coil tubes 50 are arranged in superposed hori- .zontal rows with the tubes in each of the rows from the lowermost to the uppermost rows of gradually increasing length. The particular lengths of ,the tubes of each row will be determined by the degree to which the boiler tubes are horizontally inclined. With this arrangement of the heating coil tubes, the coil may be disposed more closely adjacent the boiler tubes than would otherwisebe possible and with all of the tubes of the coil completely submerged in the boiler water.

The heating -coil supporting means of the invention may also be applied to heating coils which are disposed transversely to the boiler tubes. As shown in Fig. '1, the coil Si is inserted through an opening in the side of the boiler shell III which is closed by a sleeve 52 forming a pocket through which the boiler water may circulate. The coil head 53 is secured to the flanged outer end of the sleeve 52. Water to be heated enters through an inlet pipe 54 and after passing through the tubes of the coil is discharged to the desired point of use through outlet tube 55. The tube coil is supported by a chain 56, the ends of which are connected to the endmost coil spacer plates l8, the chain passing through the opening in I-bolt 20. Intermediate shorter chains 56' have their ends connected to the central coil spacer plate l8 and to the chain 56 as indicated. With this arrangement it will v.be seen that the tubes of the coil 5| are supported throughout their entire length in spaced relationship to the boiler tubes and that the supporting means may be readily adjustable from outside of the boiler shell. The number and location of the coil spacer plates l8 with respect to the tubes may be varied as desired to provide the degree of support desired.

The supporting chains may be connected directly to the coil spacer plates l8 as indicated in Figs. 1 and '1 of the drawings and the chain may be insulated from these plates by suitable use of electric insulating material such as fiber, so that the chain does not come into direct contact with the coil spacer plateswhich may be used for connecting the supporting chains to the coil spacer plates is illustrated in Fig. 8. Referring to this figure, the upper ends of the spacer plates are apertured and an I-bolt 51 is passed through the opening. The opening is provided with a fiber sleeve 58 having a length about the same as the thickness of the spacer plate. Fiber washers" 59 and 60 are placed on the I-bolt at opposite sides of the spacer plate l8 and a nut BI is threaded on the end of the I-bolt. The supporting chain 62 may be directly con- As pre- I Another arrangement nected to the end of the I-bolt as shown. With this arrangement the I-bolt is completely insulated from the spacer plate and from the tube of the coil so that electrolytic action and resulting corrosion of the several parts is prevented.

Thus it will be perceived that I have provided an elastic or resilient means for securing and sealing the coil head to the tube sheet, which is capable of exerting a tremendous pressure to press the coil head against the tube sheet with suflicient force to prevent leakage at all times whether the boiler is in or out of operation, and is also exceedingly compact. The coil head casing and the ventilation of the casing protects the head against corrosion and also prolongs the life of the casing.

The forms of the invention disclosed are to be, considered as preferred forms. Changes may be made in the form, arrangement and disposition of the several parts without transcending the principles of the invention. Accordingly, it will be understood that the invention is not to be limited except by the scope of the claims appended.

What I claim is:

1. A boiler comprising a shell, tube sheets, boiler tubes extending between the tube sheets, a fluid heating coilextending through a tube sheet, a head for the coil, and means including a wedge cooperating with a resilient member secured at a fixed distance from the tube sheet for forcing the head against the tube sheet to seal the head thereon.

2. A boiler comprising a shell, tube sheets, boiler tubes extending between the tube sheets, a fluid heating coil extending through a tube sheet, a

head for the coil, and means comprising a wedge cooperating with a pin secured at a fixed distance from the tube sheet for forcing the head against the tube sheet to seal the head thereon.

3. A boiler comprising a shell, tube sheets, boiler tubes extending between the tube sheets, a fluid heating coil extending through a tube sheet, a head for the coil, and means comprising a wedge cooperating with a pin having wedge contacting surfaces which may be disposed at varying distances from the tube sheet, the pins being secured at a fixed distance from the tube sheet for forcing the head against the tube sheet to seal the head thereon.

4. A fire tube boiler comprising a shell, tube sheets, fire tubes extending between the tube sheets, one of the tube sheets and the shell formv ing a smoke box at one end of the boiler, a fluid head secured to the tube sheet.

6. A fire tube boiler comprising a shell, tube sheets, fire tubes extending betweenthe tube sheets, one of the tube sheets and the shell forming a smoke box at one end of the boiler, a fluid heating coil extending through saidone tube sheet, a head for the coil disposed in the smoke box, and a corrosion resisting casing for the head having connections with the atmosphere to sheets, one of the tube sheets and the shell tonn ing a smoke box at one end of the boiler, a fluid heating coil extending through said one tube a sheet, a head for the coil disposed in the smoke box, a fluid inlet pipe for the head, a corrosion resisting casing for the head, a pipe surrounding the inlet pipe having one end connected with the interior of the casing and the other end open to the atmosphere, and means for conducting air from the casing.

8. A boiler having a shell, a bank of boiler tubes in the shell, a fluid heating coil in the shell,

a flexible member for suspending the coil out of contact with the boiler tubes, means for 'supporting the flexible member from the shell, and means for adjusting the supporting means for varying the distance the coil is suspended out of contact with the boiler tubes.

9. A boiler having a shell, a bank of boile tubes in the shell, a fluid heating coil in the shell, a flexible tension member connected to the coil at spaced points, and means supported by the shell and connected to the chain for suspending the coil out of contact with the boiler tubes.

10. A fluid heating coil comprising a plurality of tubes connected to a head and adapted to be disposed in a boiler above a bank of horizontally inclined boiler tubes with the coil tubes extending substantially parallel to the boiler tubes and disposed substantially horizontally, the tubes of the coil being of increasing length from the lowermost to the uppermost row.

' 11. A fluid heating coil comprising a head having a plurality of partitions therein disposed so as to divide the head into a plurality of fluid compartments, a plurality of loop tubes having their ends connected to the head in such manner that some of the tubes connect each compartment with another compartment, and a wall connecting with one of the partitions and providing a fluid pocket in the head into which one of said loop tubes discharges, said wall extending into one compartment and being disposed so that the pocketiormed thereby communicates with an adjacent compartment.

12. A fluid heating coil comprising a head havinga plurality of partitions therein disposed so as to divide the head into a plurality of fluid compartments, a plurality of loop tubes having means being accessible their ends connected to the head in such manner that some of the tubes connect each compartment with another compartment, and one or more walls forming fluid pockets, in the head with which one or more of said loop tubes connects, said walls being disposed in one or more fluid compartments and arranged so that the pockets formed therebycommunicate with fluid compartments adjacent to said one or more compartments. 2

13. A boiler comprising a shell, tube sheets. boiler tubes extending between the tube sheets, a fluid heatingcoil extending through a tube sheet, a head for the coil, and means including a. wedge cooperating with a member secured at a fixed distance from the tube sheet for forcing the head against the tube sheet to seal the head thereon.

I 14. A heat exchange coil including a head having a wall provided with tube holes therein, the

head having inlet and outlet openings, a first partition extending from said wall and dividing the interior 01' said head into chambers, one of which communicates'with one of said inlet and outlet openings, a second partition extending from said wall and spaced from the first partition and the first and third compartments, others of said tubes connecting the second and third compartments, the arrangement being such that by pro-.

viding an opening in the first partition the head will provide a plurality of fluid passes through the coil, or by providing openings in the second and third partitions the head will provide a single fluid pass through the coil.

15. A boiler having a shell, a bank of boiler ,tubes in the shell, a fluid heating coil in the shell,

a flexible member for suspending the coil out of contact with the boiler tubes, means for support- .ing the flexible member from the shell, and

means for adjusting the supporting means for varying the distance the coil is suspended out of contact with the boiler tubes, said adjusting from outside the shell.

'VIRGIL W. MORAY.

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