US2140279A - Heat exchange apparatus - Google Patents

Description

De c. 13, 1938. w. s. BUELL HEAT EXCHANGE APPARATUS Filed April 23, 1.931 2 Sheets-Sheet l Dec. 13, 1938. w 5 BUELL HEAT EXCHANGE APPARATUS 2 Sheets-Sheet 2 Filed April 25, 1931 flATTO EY Patented Dec. 13, 1938 UNITED. STATES PATENT OFFICE 2,110,279 HEAT EXCHANGE APPARATUS Wales Saxton Buell, Dansville, N. Y.,

Foster Wheeler Corporation, New York, N.

assignor to 32.,

The object of my invention is to provide novel means for supporting heat exchange apparatus such as a steam superheater, in certain types of steam generators, for example, the type having vertically disposed banks or groups of tubesinclined somewhat from the horizontal between which is disposed a. superheater, generally called an interdeck superheater. r

The nature of my invention will become ap-' parent from the following description considered in connection with the accompanying-drawings, wherein I have illustrated preferred forms of'my invention in connection with one type of known steam generator. It will, of course, be obvious that many changes may bemade in the forms dis closed without departing from the spirit of the invention, and that my improved manner of supporting superheaters may be applied to other types of steam generators. 4

In the drawings:

Fig. 1 is a vertical sectional view oi an inter deck type of water tube boiler embodying the present invention;

Fig. 2 is a broken sectional view taken substantially on line 2-2 of Fig. 1;

Fig. 3, is a partial sectional view taken 3-3 of Fig. l; V

Fig. 4 is an elevational view taken on line H of Fig. 2;

Fig. 5 is a partial vertical sectional view showing another form of superheater;

Fig. 6 is a view similar to Fig. other form of superheater;

Fig. '7 is 'a sectional view taken on line 1-! of Fig. 5; and

Fig.8 is a sectional view on line 8--8 of Fig.- 6.

like'characters of reference refer to like parts throughout the several views.

Referring, in general, tothe disclosure of Fig. l, a superheater of the interdeck type is shown apon line 5, showing anplied to a typical water-tube boiler, the frontend of which superheater, that is to say; the and opposite the header end, is supported on the water leg of the boiler adjacent to it. To this water leg of the boiler, supporting brackets are bolted or otherwise secured. One suitable term of supporting bracket comprises a member 01 suitable form and preferably of a length such that it will contact with two or more nipples. These members are secured to the nipples by any d e-' sired means such as bars and bolts. I

Referring more particularly to Fig. 1, reierence character l0 designates the setting oi a steam generator. The setting includes the usual steelwork comprising vertical and horizontal angle and channel bars 9 and the brick-work 8, and the usual heat insulation, closures and the like. The setting encloses a furnace chamber 1; in the lower portion thereof and the boiler generally indicated at G in the upper part thereof.

directly supports nected by nipples 94 to the headers I3. The weightadditional supporting means may be tubular nipples i8 is connected to the row oi I at the bottom. The nipples are surrounded by refractory blocks IS. The various tubular elements are suitably expanded into the headers. Each of the vertical headers is connected to one nipple. At the bottom 6f each nipple a lower header is connected thereto. There are opposite rows of lower headers 82 and H3. The headers oi the row l2 are connected to the respective nippies ll. The headers oi the row I3 are connected to the respective nipples 18. It will be seen that the header it is higher than the header l6 and thatthe header I2 is higher than the header l3. Nipples'll, headers l6, nipples l8 and headers I3 comprise a conduit for the passage of water downwardly from the drum 20 and hence may be termed downcomers, while headers A lower bank of horizontally inclined water .Anupper bank of horlzontallyinclined water tubes ll connects the headers l5 and it. There is an appreciable space between the two banks of water tubes in which is situated a superheater, presently to be described. It will be seen that the nipples ll and I8, in eflect, are spacers between the lower units comprising the tubes Ii and the headers l2 and I3, and the upper units comprising the tubes l4 and the headers I5 and it. Each connected set of headers." and i5 and nipple il constitute an upflow water leg. Each group of connected headers l3 and I6 and nipple l8 constitute a downflow water leg.

The weight of the right-hand part of the boiler, as shown in Fig.- 1, is supported by a cradle carried on horizontal channels 9| forming part of the steel-work of the setting and in turn supported by vertical channels. The cradle 90 a mud drum 93, which is conat the To'pposite end or side-oi. the boiler is carried by suspension from eye-bolts suspended from across channels 96 carried by a vertical member 97 oi the steel-work. Eye-bolts 95 are secured to headers I5. The weight of the lower headers l2 and associated parts is carried through the nipples II from'the headers I. If desired, supplied.

i5, nipples l1 and headers i2 comprise a conduit lorthe passage oi steam and water upwardly toward the drum 20, and hence may be termed upcomers.

The channel 92 may be carried upwardly or some of the steel members 9 may be arrangedv to secure and support the transverse channel 33. The

steam and water drum 20 maybe suspended from overheadsteel-work. n

On top of the upper row of tubes ofthe lower bank H is a baflle 25, which extends froimheaders |3 to approximately midway of the interior of the boiler setting. From this point a. vertical 10 baille 26 extends upwardly. Vertical baflle 28 and baflie 25 form an up-pass 29 betweenthe baflie 26 and the nipples Extending downwardly from the roof 23 of the boiler setting is a baflle 21, which extends through the upper tube bank l4 and terminates at the top of theinterspace between the tube banks. An outlet 28 is provided for the products of combustion. All of the tubes of the lower bank II are exposed to radiant heat of the fire in the furnace 'l. Products of combustion flow upwardly through the up-pass 29, thence downwardly through the down-pass between baflles 26 and 21, and thence upwardly in a second up-pass between baiile 21 and headers l6, and thence between nipples 2| 25 and out through the outlet 28.-

A steam ofitake pipe 22 connects the top of the steam and water drum 28 with an upper header 30 of thesuperheater. Upper header 30 extends through the brick-work of the setting 30 and theends thereof are outside the setting, as shown in Fig. 2. Header 38 is adjacent bame 28 and on the side thereof opposite to the up-pass 29. Thus, this header is protected from the intense radiant heat of the fire and the hot'gases flowing through the up-pass. v

Below inlet header 30 and having the same relative position with respect to bailie 28 and the Lowerup-pass is a lower superheater header 3|. header 3| likewise passes through the walls of an the setting, and its ends are outside the setting as shown in Fig. 2. Connecting headers 30 and 3| area plurality of rows of vertically disposed multi-loop elements, the leads of which pass through bailie 26 and extend within the up-pass 29, thebend portions thereof being adjacent the nipples I! but spaced somewhat therefrom in order to allow for expansion. The loops of 'each superheater element are indicated 66, 81 and 68 respectively. Within upper superheater header 30 are two diaphragms 99 having drainage recesses I98 at the bottom thereof. Diaphragms 99 are so disposed that the number of tube connections to the header between them is equal to the sum of the tube connections laterally thereof. Within header 3| is a centrally disposed diaphragm 99, also having a drainage recess I68 at the bottom thereof. The steam to be superheated passes through theconduit 22 and into the left-hand end of header 38 (as shown in 60 Fig. 2). The steam thence passes through a group of the-superheater elements atthe inlet side of the nearest diaphragms 99. The steam after passing through this group of superheater elements enters the header 3|. 65 passes into a second group of superheater elements and returns therethrough 'to the. space in superheater header 30 between the diaphragms 99. Thence the steam passes through a third group into header 3|, to the right of the diaphragm in header 3|, as shown in Fig. 2, and thence through a fourth group of superheater elements back to header 39, passing out through the right-hand end I64, as shown in Fig. 2, of header 36.

15 The superheater elements are arranged parallel Here the steamto the boiler tubes, that is, the straight portions thereof are somewhat inclined from the horizontal.

The headers 30 and 3| of the superheater are supported adjacent their ends on the setting. Channel bars 33, forming a part of the steelwork of the setting and tightly secured to the other members of the steel-work as by rivets,

mextend horizontally along each side of the setting somewhat below the header 3| of the superheater. The ends of the header 3| rest on header crutches 34 mounted on the channels 33 and the header and supporting crutches are secured to the channel by means of U-bolts 35. The header 30 is supported at its ends by support frames 36 suitably carried by the setting l0 and secured to the channels 33. The ends of header 30' rest on header crutches 31 mounted on angle bars 38 which are secured to the'support frames 36 and U-bolts 39 secure the header to the sup-' port frames 36. Refractory material 40 forming part of the-baille 26 protects the headers 36 and 3| and the connections of the elements 32 therewith from the intense heat of the products of combustion flowing through the first pass of the boiler.

The front end of the superheater, that is to say, the end opposite the header end, is supported on the vertical nipples I! which connect the headers l2 and I5 of the lower and upper banks of tubes II and 4 or on the headers |2 or both. To this end, a plurality of supporting brackets 4|.are bolted or otherwise secured to the lower ends of the nipples as clearly shown. One suitable form of supporting bracket 4| comprises a channel member preferably of a length such that it will contact with two or more nipples. The channels are secured to the nipples by any desired means such as the bars 43 and bolts 44.

Each of the loops 66 of the superheater elements has a supporting foot welded or other.- wise secured thereto so that when the superheater is in position, the feet 45 will bear on the supporting brackets 4|. It will be apparent that the dimensions of the supporting feet and brackets should be such as to allow ample expansion of the superheater and the adjacent boiler parts under the influence of the heat of the combustion gases. Spacers 69 and 19 are provided for the front and header ends of the elements to space the loops and the legs of each loop. The upper .legs ll of each loop are substantially straight while the lower legs 12 are arched upwardly or toward the upper legs of each loop as shown, to provide, with the spacers 13, a support for the intermediate portions of the upper legs H. The upper front end of the superheater is steadied by the steadying clamps 65.

The brackets 4| may rest on headers l2 so that the weight of the superheater acts ,directly downwardly on headers |2, the bolts 44 merely serving to hold the brackets in place, or brackets 4| may be somewhat 'above headers I2 and car'- ried entirely by nipples H. In either event, the

load is carried in direct vertical alignment with eye-bolts 95. The brackets are attached to the water leg of the boiler in such a way that the ment with the boiler supports carrying this water leg. The steel-work of the setting rigidly connects the mountings for the superheater head- 7 ers and the boiler supporting steel work 90 so that there is no distortion due to expansion.

In this manner, so-called interdeck superheaters may be supported in position in the boiler entirely independently of the boiler tubes. The

vertically disposed, substantially U-shap'ed, nested elements 41 connecting the headers 30 and 3|.

The upper leg or branch 48 of each element 41 is substantially straight from the header 30 to the bend in the element, but the lower leg 49 of each element is arched upwardly or toward the leg 48 as shown. The superheater as a unit is supported independently of the boiler tubes in substantially the same manner as the superheater shown in Fig. 1 that is, by means of the supporting feet 45, supporting brackets secured to the front water leg and the spacers 46 adjacent the bend in the elements. In this case, however, the supporting brackets are in the form of castings 15, one of which is threaded onto each of the nipplesv I1 as shown. This bracket is shown to illustrate a variation only of its form and may be changed as best suits individual requirements.

Intermediate their ends, the legs 48 and 49 are spaced apart by means of spacers 50.- A spacer 5!, in substantial alignment with the spacers 50 serves to space the legs, of the innermost elements of the superheater and further supports the upper legs 48 of the elements. The spacers are held in place bysuitable means, preferably by lugs welded to the tubular elements. If desired, a plate or equivalent type of spacer may be used at this and other points. In this manner, the legs of the elements are prevented from sagging intermediate their ends. The arches therein prevent sagging of the lower legs 49 and, together with the spacers, prevent sagging of the upper legs 48. J

In the formof superheater shown in Fig. 6, sagging of the legs of the elements is prevented and an intermediate support therefor is provided by utilizing the principle of the triangular. truss in the superheater structure. comprises a plurality of rows of vertically disposed, substantially U-shaped. nested elements 52 connecting the headers 38 and 3|, and the front end of the superheater is supported from I the water legs substantially as in the forms shown in Figs. 1 and 5. As shown in Fig.6, the upper leg 53 of each of the superheater elements is substantially straight. The lower leg 54 of the two outermost elements of each. vertical row is also straight, while the lower legs 55 ot the three inner elements are arched upwardly or toward the upper legs 53. Spacers 55 and 51 suitably space the elements at their U-bends and adjacent thereto, while spacers 58 space'the upper and lower legs of the elements intermediate their ends and the spacer 59 spaces the legs of the innermost elements and supports the upper legs of the elements. It will be clear that the lower legs 54 of the outermost elements are .subjectedto tensile stress bythe thrust of the archedlegs 55 and The superheater serve as resistants to such thrust. The tension thus produced in the lower legs of these elements tends to prevent them from sag ing. If desired,

a support may be provided at this point which is suspended from the arched elements immediately above to prevent sagging if the tension is not sufficient to do so. The upper legs 53, being supported intermediate their ends by the spacer 59,-

are also prevented from sagging. ,As shown in Fig. 6, the lower legs of the two outermost ele- .ments in each vertical row are-used as tension members. but it will be understood that the lower leg of the outermost element alone or the lower legs of more than two elements may be used if desired. The structure shownin Fig. 6 is particularly advantageous with relatively long superheaters. v

As shown in'Fig. 8, the supports in which the supporting feet 45 rest comprise a plurality of cast-iron blocks 18 and 11 which engage the nipples l1 and are retained in place by bridge members 18 and bolts 19. This bracket is also shown to illustrate one variant form and obviously the form may be changed to suit individual requirements.

Since changes may be made in the forms of the invention herein disclosed without departing from the principles of the invention, it will be understood the invention is not to be limited excepting by the scope of the appended claims.

' What -I claim is:

1. .Heat exchange apparatus comprising a plurality of superposed tubular elements, and. means for supporting one of said elements at its end portions, at least one of the elements being arched in an upward directionin an intermediate portion thereof to provide a support for the intermediate portions of the elements disposed above said one element.

2. Heat exchange apparatus comprising a plu rality of superposed return bend tubular ele-' ments, means for supporting the lowermost element at its end portions, said lowermost element being arched upwardly in its intermediate portion, and means interposed between said arched portion and the element disposed immediately thereabove for supporting the intermediate portion of said last mentioned element.

3. Heat exchange apparatus comprising a plurality of superposed return bend tubular elements, and means for supporting the lowermost element at its end portions, said lowermost element and certain other elements disposed thereabove being arched upwardly in their intermediate portions respectively to provide supporting means for elements disposed above said arched elements.

4. Heat exchange apparatus comprising a plu rality of nested U-bend tubular elements, and -means for supporting the lower leg of the outer- ,most element at its end portions, the lower legs of the elements being arranged and supported in such manner as to form a. triangular truss to support the upper legs of the elements and prevent sagging of the elements of the apparatus.

WALES BAXTON BUILD.

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