US2154178A - Fluid heater - Google Patents

Description

April l1, 1333. v. w MORAY FLUID HEATER Filed Sept. 21, 1935 4 Sheets-Sheer?I 1 V. W MORAY April 1 1, 1939.

FLUID HEATER SheetAs-Sheet 2 Filed Sept. 2l, 1935 afi.

NTOR Ma/mf.

TTORNEY mv VR6/L L', Z

April 1l, 1939. vl Wl MQRAY 2,154,178

FLUID HEATER Filed Sept. 21. 1935 4 Sheets-Sheet 3 l l ATTORNEY v. w, MoRAY 2,154,178

FLUID HEATER rled Sept* 2l. 1935 4 Sheets-Sheet 4 April ll, 1939.

mvENToR t .ATTbRNE Patented Apr. 11, 1939 UNITED STATES PATENT OFFICE FLUID HEATER Virgil W. Moray,

Akwa Heaters.

Application September 21, 1935, Serial No. 41,533 15 Claims. (Ci. 257-236) This invention relates to heat exchange equipment and more particularly pertains to auxiliary fluid heating coils for steam boilers, water heaters or the like.

In general, fluid heating coils of this character have had but small heating surface due primarily to practical diiliculties in installing the coils in the boilers and in so constructing them that they may be removed. Ordinarily, a manhole or handhole has been provided through which the coil could be inserted and removed and another hole in the boiler was required for the pipe outlets of the coil. Additionally, the coil heads have usually been of cast metal and bolts have been utilized to secure the coil head parts together. In some instances the coll pipes have been expanded into the coil heads but to provide greater heating surface, brazing has been resorted to, but this method of securing the coil pipes to the heads proved too expensive for general use.

The present invention provides novel iluid heating coils of the character referred to and also provides a novel method of installing the coils in a steam boiler, water heater or the like. The coils of my invention are characterized by a relatively large heating surface, compactness, and small coil heads of wholly novel construction. Only one small opening in the boiler is required for each coll and the coils are readily installed and removed from boilers or water heaters.

The invention further provides novel resilient means for securing the coil heads in position in boilers or water heaters.

Further features and advantages of the invention will appear from the following description when considered in connection with the accompanying drawings forming a part thereof, in which: g

Fig. l is a vertical sectional view of a ilre tube boiler having an auxiliary iiuid heating coll embodying the present invention.

Fig. 2 is a combined end elevational and sectional view, the latter being taken on line 2-2 of Fig. 1:

Fig. 3 is a horizontal sectional view on an enlarged scale, taken on line 3 3 of Fig. l;

Fig. 4 is a vertical sectional view taken on line 4-4 of F18'. 3: v

Fig. 5 is a partial plan view, with parts in section, of the heating coil and the coil head casing illustrating the method of installing the coll in a boiler;

Fig. 6 is a perspective view of the coil headA casing i Fig. is a horizontal sectional view of a cylindrical shell steam boiler or water heater having another form of fluid heating coil embodying the invention:

Fig. 8 is a partial vertical sectional view taken on line 8 8 of Fig. 7; l

Fig. 9 is a sectional view taken on line 9-8 of Fig. 7:

Fig. 10 is a horizontal sectional view similar to Fig. 3, showing another form of coil and coil head securing means;

Fig. 11 is a sectional view taken on line II--II oi Fig. 10;

Fig. l2 is a sectional view taken on line I2--I2 of Fig. 10, and

Fig. 13 is a partial sectional view showing another form of coil head securing means.

Like characters of reference refer to the same or similar parts throughout the several views.

Referring to the drawings, reference character I0 designates the shell of a nre tube boiler having an auxiliary uid heating coil embodying features of the invention. The boiler has a plurality of fire tubes II and I2 extending between tube sheets I3, I4 and I5, vide two passes for the products of combustion through the boiler. The boiler is provided with a grate I6, a transfer chamber II and a smoke box I8 to which the inlet end of a flue I9 is connected. Water fills the space 20 between the tubes Ii and I2 and is maintained at the level 2i. It will be understood that this particular type of boiler is not essential to the invention, but that other types of boilers may be employed if desired.

Referring particularlyto Figs. 1 to 6 inclusive, the coil illustrated is made in two sections indicated A and B, and is arranged to fill substantially the entire volume of the boiler above the boiler,

tubes and below the water level 2I. Both sections are identically arranged but when installed in a boiler, are reversed, as shown. Each section consists of a iiuid inlet lead 22 and an outlet lead 23 which are connected by a plurality of tube loops the latter oi' which are arranged to form a relatively flat helicoidal coil. The inlet lead of each section continues into a plurality of similar and adjacent laterally disposed elongated loops 24 and the outlet lead 23 connectsi with the most remote loop 24' through a plurality of straight portions connected together by return bends 25 which extend through the space bounded by the loops 24.

The sections A and B of the iluid heating coil are originally formed with the several loopsV 24 spaced to the extent it is desired they be spaced all arranged to pro- A cooperate to form the coil when installed in the boiler. Just prior to inserting the coil section in the boiler, the sections are contracted sumciently to permit them to be passed through an opening in the tube sheet or the shell of the boiler as illustrated in Fig. 5. The coil sections are inserted in the boiler above the iire tubes through an opening 26 in the tube sheet III, which in this instance is rectangular in configuration and is only large enough to permit one of the coil sections to be readily passed therethrough. After the coil section, for example section A. has been passed through the opening 28 into the boiler, the several loops thereof spring apart to approximately their original spaced position, due to the resiliency of the metal of the tubes. After section A has been installed, section B is contracted and then passed through the opening 28 and expands to approximately its original condition. The leads 22 and 23 are brought into horizontal alignment and are thereafter expanded into a base plate 21 which forms part of the coil head. This plate is provided with the desired number oi' tube holes and the ends of the leads are passed through these holes and are expanded thereinto. 'Ihe tubes may be brazed to the base plate instead of being expanded thereinto. if desired.

In the form of the invention disclosed in Figs. 1 to 6, applicants novel coil head consists of two cooperating plate-like portions, one of which is the aforementioned base plate 21 and the other of which is the cooperating outer plate 2B. Plates 21 and 2l, as shown, are of rectangular configuration and are of rectangular cross-sectional coniiguration essentially. Base plate 21 is provided with tube holes to receive the coil leads 22 and 22, and plate 2l is recessed to provide a circular transfer chamber 28 and is further threaded at opposite sides of the recess 2! to receive the ends oi' fluid inlet pipe 20 and outlet pipe 2|. One or more gaskets 32 are elnployed between the plates 21 and 2B to prevent leakage of the uid flowing through the head; to separate the inlet and outlet chambers 33 and I4 respectively from the transfer chamber 29 and to maintain the head plates in spaced relationship to provide adequate volume for the inlet, transfer and outlet chambers. A suitable gasket l is employed between the shell or tube sheet I0 of the boiler and the plate 21 to prevent leakage therebetween. -With this arrangement it will be seen that the entire coil head consists essentially of two cooperating plates which may be bar stock from the mill and which with simple machining operations may be finished to provide parts which head. The simplicity and economy of manufacture possible with this coil head of my invention will be apparent.

In this instance the coil head is disposed in the smoke box Il oi' the boiler and protectingmeans are provided to prevent corrosion of the head and its connections which would result from contact oi' the combustion gases with the metal parts of the head and its connections. As shown, the protective casing is rectangular in cross-section. The casing is fabricated from sheet metal parts which are secured together preferably by spot welding. The upper and lower portions It and I1 f(see Fig. 8) oi' the casing consist of plates h fing short upstanding flanges at their ends the sides ll and il are dat plates which are sebured by welding or otherwise to the flanges of `the upper andlower portions. The casing is to the tubesheet il of the boiler so as to Surround the opening 2| by welding the inner ends of the sides 38 and 38 and the upper and lower portions 36 and 31 thereto. 'I'he casing is so formed that the inner edges of the sides 38 and 39 only, engage the tube sheet when the casing is placed thereagainst so that the casing does not have to be made exactly square. 'Ihe spaces between the tube sheet and the inner edges of the upper and lower portions are filled when the casing and these portions are welded in place. A sheet metal plate 4Il having dimensions such that it forms a forced iit with the inner surface of the casing provides a cover for the outer end thereof. The casing is provided with an opening 4| in the side wall 39 to permit the coil inlet pipe 30 to pass therethrough. The upper portion 36 is also provided with an opening 42 through which the coil outlet pipe 3l passes. Pipes 30 and 3| pass through Ventilating sleeves 43 and 44 respectively, which have their inner ends secured to the casing at the peripheries of the openings 4| and 42 respectively, and have their cuter ends passing through and extending slightly beyond the smoke box IB.

'I'he coil head casing is also utilized to aid in securing the coil head to the tube sheet illor to the shell of the boiler and to secure together the several plates of the head. In the form of the invention shown in Figs. 1 to 6, the means employed are two wedge bars 45 and 46 shown more particularly in Figs. 3 and 4. These wedge bars have a rectangular cross-section and are slightly longer than the length of the coil head and the width of the coil head casing. Each wedge bar is provided with a wedging surface 41 at one end and a wedging surface 48 at the other end, both wedging surfaces .being inclined in the same direction. The wedging surface 41 is disposed slightly inwardly of the end of the wedge bar, as shown in Fig. 3, to provide a surface 4l which is parallel to the surface of the wedge bar which engages wear strips 28", coin-` prising thin metal strips disposed between the outer head plate and the wedges. Aligned wedge openings 50 and 5i are provided at the upper and lower portions of the coil head casing of sufficient area to accommodate the wedge bars 4l and 48. After the coil head has been placed in position and the coil head casing has been secured to the tube sheet lil of the boiler and the wear strips 28" are in place, the wedge bars are inserted through one side of the casing until the wedge surfaces 41 and 48 engage the cooperating edges of the openings 50 and Il. In this position the wedge bars engage the wear strips and when the outer ends of the wedge bars are driven inwardly, it will be seen that the action of the wedging surface on the casing will force the coil head plates together at the same time that the coil head or the base plate 21 is forced against the tube sheet i0 or the boiler shell. When driven in place, the wedge bars 42 and 46 arch somewhat between the points at which they are supported by the casing, due to the resiliency of the material of the wedge bars.

. In installing the coil in the steam generator. an opening such as 28 is made in the tube sheet or shell I0 of the generator, one of the coil sections after having been contracted as illustrated in Fig. 5. is passed through the opening with the inlet and outlet leads positioned near the opening and the other section B after having been contracted, is then passed through the opening and is rested on the uppermost row of tubes i2 of the boiler ill expanded condition with its inlet and outlet leads positioned near the opening 26.

- shell or' tube sheet The leads of b'oth sections (now expanded) are passed through the tube holes in the base plate 21 oi the coil head and are thereafter rolled into the base plate to secure them thereto. Prior to securing the coil section leads to the base plate. the'gasket 35 is placed. between the shell or tube sheet IB and the base plate. Thereafter the coil 4head casing is secured to the shell or tube sheet III by welding preferably. gasket 32 is placed ln position over the base plate 21, the cooperating outer head plate 2B is then placed in position, wear plates 28" are disposed in contact with the coil head plate 28 and the wedge bars l5 and i6 are then passed through the casing as previously described, and are driven home to wedge the cooperating parts of the coil head together and simultaneously to secure the coil head to the ill. Thereafter, ythe inlet and Aoutlet pipes 30 and 3l areattached to the plate 28 of the coil head and the Ventilating sleeves I3 and I4 are placed in position. Finally the casing cover 40 is forced into position in the casing The sequence of steps set forth hereinabove 'may be considered as the preferred method of installing the coil and its associated equipment in the generator or water heater, but the sequence may be variedv if desired.

To remove the coil or any section thereof for cleaning or repair, the sequence of steps heretofore enumerated are reversed. Before any secy tion of the coil may be removed, it must of course, be contracted to an extent suilicient to permit it to be passed through the opening 28.

The wear strips disposed between the coil head and the wedging means assist in the placing of the wedges in coil head securing position. Additionally they function to distribute the force exerted by the wedges on the coil head and thereby serve to prevent buckling or arching of the coil head plates. -j A Figs. '1, 8 and 9 illustrate the appllcationo the invention to a steam generator or hot water heating boiler having a cylindrical shell 55. In this instance also the heating coil. includes a plurality of 'U-bend. tubes 56 instead of the accordion coils disclosed in Figs. l to 6. The coil head casing is the same as the coil head casing inFlgs. l to 6, but an adapter 51 is employed' through which the casing is secured to the boiler shell. Adapter 51 is of rectangular coniguration in transverse cross-section and its outside dimensions are such that the coil head casing snugly nts over the outside end of the adapter. The inside or boiler end of the adapter 51 is shaped to fit the boiler shell and to enclose the opening 58 which is made therein so that the coil tubes 56 may be passed therethrough and installed in the boiler. 'Ihe adapter is preferably welded to the boiler shell but may be secured thereto by other suitable means if desired. The base plate 59 of'the coil head 4is the same as base plate 21 in Figs. l to 6, excepting that the tube holes are disposed to accommodate the ends oi the U-bend tubes 66. The outer section Bil ofthe coil head is similar to plate 2l excepting that it is ynot recessed to provide a transfer chamber. The

outer plate 80 is merely drilled and tapped to provide threaded openings for the inlet and outlet pipes lli and Il. An extra thick gasket Il is utilized tospaoe the plates 5,9 and O0 apart to provide inletrand outlet chambers l2 and Il.

In tha-form of invention illustrated in Figs. l0,

.11 and 12, the coil head is similar to the coil head disclosed in Figs. 1 to 6, with the exception' that the outer head plate 14 is not recessed to provide a transfer chamber. The fluid heating coil ls in tvvv sections C and D. as in Figs. 1 to 6. and each section consists generally of double U- bend tubes ll and 12. Each of these sections has an overall width, such that it may be passed through the opening 1I in the ,shell or tube sheet lil of the boiler. In .this case the coll sections are rigid, that is to say they are not arranged for `expansion andcontraction as the coil sections of Figs. l to 6 are arranged. The outer or cooperating plate 1l of the coil head is simply a rectangular strip or barlhaving overall dimensions substantially the same as those of the base plate 10. with threaded openings therein to re ceive the iiuid inlet and outlet pipes 15l and 16, respectively. A In this instance, a diierent form of wedging means is utilized to secure the coil head to the shell or tube sheet lll and to force the cooperating parts of the head together. The wedging means consists of aplurality of resilient wedges 11, each of which consists of a single loop of spring steel or other suitable resilient matevrial with the ends of the loop disposed so that per and lower portions of the coil head casing. These pins are vertically disposed as shown, and each pin cooperates with two wedges 11 adjacent the upper and lower portions of the pin. In this form of the invention no wear plates are utilized between the wedges and the coil head, .but such wear plates may' be utilized if desired.

, In the form of the invention shown in Fig. 13, the wedging member Il consists of two resilient wedges 85 and I6 integral with each other. The wedging member and the wedges are so arranged that they cooperate with the side portions I1 and 88 of the coil head casing. Generally two v wedging members Il will be utilized sbstantially are driven through suitable apertures in the upor shell Il and to secure the coil head sections together. As shown. wear plates l! which are similar to the wear plates B3 and 6l of Figs. 1, 8 and 9 are utilized.

'I'he reculent wedges, such as shown in Figs. 10'

to i3 inclusive, as well as the wedge bars I5 and I8, are advantageous for the reason that they automatically take care of the expansion'and construction of the coil head and the coil head casing with they result that iiuid tightness maintained and the life of the coil head gaskets are increased by virtueof the fact that the wedges maintain 'gasket tightness upon contraction after expansion of the coil head Darts- From the foregoing disclosure it will be ypreceived that I have provided a fluidv heating coil which is compact, provides a large fluid heating surface and. which may be installed and removed through a single relatively small 4opening in a boiler shell or in a tube sheet. My novel coil head construction is characterized by great simplicity and economy of manufacture by reason of the fact that the head may -be made from secand its connected tions oi bar stock from a mill so that casting of the head or head parts is not necessary. The bar stock from the mill need only be subject to simple machining operations to prepare the bar stock for use as coil heads. I'he means herein disclosed for securing the coil head to the boiler shell or tube sheet and for securing the coil head parts together is also characterized by simplicity and economy of manufacture. Threaded members such as nuts and bolts or the like are not necessary and the securing means, the wedges, automatically take care of expansion and contraction of the coil head and its connected parts so that gasket tightness is maintained under all conditions.

When the coil heads are disposed in a smoke box of a iire tube boiler, the coil head casing provides means for adequately protecting the coil head and its connected parts from the corrosive action of the combustion gases. The casing is also ventilated so that any products of combustion which may leak into the casing are removed therefrom into the atmosphere. Additionally.`

the casing functions as a means for cooperating with the means for securing the coil head to the shell or tube sheet of the boiler and for securing the several parts of the coil head together, and further functions to reenforce the tube sheet or boiler shell around the opening provided for the coil.

Since changes and variations in the particular combinations of elements herein disclosed may be made without departing from the principles of the invention or transcending the scope thereof. it will be understood that the invention is not to be limited except by the scope of the appended claims.

What is claimed is: y

1. Heat exchange apparatus comprising a shell, a fluid heating coil having tubes extending through an opening in the shell, a coil head connected to the tubes, a coil head casing around the opening and connected to the shell and wedging means directly engaging the casing for securing the coil head to the shell.

2. Heat exchange apparatus comprising a shell, a iluid heating coil having tubes extending `through an opening in the shell, a coil head connected to the -tubes and having a plurality of cooperating sections, a coil head' casing around the opening and connected to the shell, and wedglng means engaging the casing for securing the cooperating sections of the coil head together and ior securing the coil head to the shell.

3. A heat exchange coil comprising a plurality of connected and adjacent loops arranged to form a relatively at helicoidal coil anda return bend tube connected to one of said loops and extending through the space deiined by said loops.

4. Heat exchange apparatus comprising a cy- Iindrical shell, a iluid heating coil having tubes extending through an openingin the cylindrical wall ofthe shell, a coil head connected4 to the tube,` a tubular adapter secured to the shell around the opening and a coil head casing secured to the adapter.

5. Heat exchange apparatus comprising a shell having an opening therein, a fluid heating coil extending through the opening, a head for the coil, a casing for the head having an opening therein, and wedging means inserted through said opening for securing the coil head in position against the shell.

6. A heat exchange coil comprising a plurality of connected and acUacent tube loops, tubular coil leads connected to the terminal loops of the coil, one of said leads extending through the space defined by the tubes forming said loops and having a part thereof disposed in proximity to the other lead, the portion of said one lead which lies within said loops having a return bend por-` tion which permits the coil Vto be laterally expand`v ed and contracted by movement of said loops to-i ward and from each other Without substantial displacement of the end of said lead.

7. Fluid heating apparatus including iluid conducting tubes connected to a head comprising two fiat plates perforated solely for tube connections to the head, said tubes being connected to one of said plates, iluid inlet and outlet leads connected to the other plate, iiuid sealing means intermediate the plates to space the plates apart to provide uid chambers therebetween, and means exterior of said plates 'to hold said plates together.

8. Fluid heating apparatus including iiuid conducting tubes connected to a head comprising a base plate and an outer plate, uid sealing means intermediate the plates to space them apait to provide fluid chambers therebetween, and means for imposing pressure on the'outer plate and independent of penetration of the base and outer plates for securing the head in position on the member with which it is to be used and for maintaining the plates in assembled relationship.

9. Heat exchange apparatus comprising a shell having an opening therein, a iiuid heating coil extending through the opening, a head for the coil, and resilient wedging means comprising a loop of resilient material for securing the coil head in position against the shell.

l0. Heat exchange apparatus comprising a shell yhaving an opening therein, a uid heating coil extending through the opening, a head for the coil, wedging means having a plurality of connected and spaced Wedgng surfaces, and means secured to the shell an'd acted against by said Wedging means to secure the coil head in position against the shell.

1l. Heat. exchange apparatus comprising a shell having an opening therein, a fluid heating coil extending through the opening, a head for the coil, resilient wedging means, and means secured to the shell and acted against by said wedging means to secure the coil head in position against the shell. l

12. Heat exchange apparatus comprising a shell having an opening therein, a fluid heating coil extending through the opening, a head for the coil, resilient wedging means, and means secured to the shell and acted against by said wedging means to secure the coil head in position against the shell, said wedging means comprising a loop of resilient material so arranged that one end of the loop engages another portion of the loop when the wedging means is in securing position.

13. Heat exchange apparatus comprising a shell having an opening therein, a nuid heating coil extending through the opening, a head for the coil, wedging means. and means secured to the `shell and acted against by said wedging'means loops of the coil and with one of said leads extending through the space dened by the tubes forming said loops and being bent to provide a resilient portion whereby said lead may be con` tracted and expanded, said lead having a. part thereof disposed in proximity to the other lead, and a single coil head for all of said coil sections to` which said leads are connected.

VIRGIL W. MORAY.

CERTIFICATE OF CORRECTION. Patent No. 2,151.1.,178. April 11, 1959.

VIRGIL W. NORAY.

It is hereby .certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5 second column, line Il?, for "sbstantially" read substantially; line 60, for "construction" read contraction; line 67-68, for "preceived,"Y read perceived; page li, first column, line 614 claim il, for "tube" read tubes; and that the said Letters Patent should be read with this correction therein that the same may conform to the record ofthe case in the Patent Office.

signed yand sealed this 16th day of May, A. D. 1959.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

loops of the coil and with one of said leads extending through the space dened by the tubes forming said loops and being bent to provide a resilient portion whereby said lead may be con` tracted and expanded, said lead having a. part thereof disposed in proximity to the other lead, and a single coil head for all of said coil sections to` which said leads are connected.

VIRGIL W. MORAY.

CERTIFICATE OF CORRECTION. Patent No. 2,151.1.,178. April 11, 1959.

VIRGIL W. NORAY.

It is hereby .certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5 second column, line Il?, for "sbstantially" read substantially; line 60, for "construction" read contraction; line 67-68, for "preceived,"Y read perceived; page li, first column, line 614 claim il, for "tube" read tubes; and that the said Letters Patent should be read with this correction therein that the same may conform to the record ofthe case in the Patent Office.

signed yand sealed this 16th day of May, A. D. 1959.

Henry Van Arsdale (Seal) Acting Commissioner of Patents.

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