Патент USA US2104937код для вставки
Jall- 11, 19358»l c. s. TURNER 2,104,937 BOILER SUPERHEATE'R Filed sept. fr, 1934 9@ |17 5 Sheets-Sheet l ì„ onä Nv» ® O \4 N UIilm/IM .w _ G O .o ® O Ö O 6 O O G O . O` O oÑ N. @i o BY JM(l a www?? ATTOR EYS. y Jan. 11, 1938. C_ 5_ TURNER l 2,104,937 BOILER SUPERHEATER Filed Sept. 7, 1934 3 »Sheets-Shawl 2 _ l/42 W@ W ì\\\\\\\\\\\\\\\\è 6/ ' INVENTOR. @?arl'ßs «if/ärmer" Jan. 11, 1938. c. s. TURNER 2,104,937 BOILER SUPERHEATER Filed Sept. 7, 1934 3 Sheets-Sheet 3 Patented Jan. 11, 1938 ' Urra 2,104,937 ATENT OFFICE sTATEs 2,104,937 BOILER SUPERHEATER Charles S. Turner, Detroit, Mich. Application September 7, 1934, Serial No. 743,068 8 Claims. (Cl. 122-481) This invention relates to boiler superheaters, A further object contemplated by this inven and incorporates amo-ng its particular objects im tion is the provision of a novel water-regulated provement of superheaters of the varieties dis radiant superheater adapted for use in locomo closed in my copending applications Serial Nos. tive boilers and of very compact construction, in e: ;.- 496,868, filed November 20, 1930, “Superheater which no steam inlet connections to the super 5 construction”; 512,675, ñled January 31, 1931, heater or discharge connections for the cooling “Superheater construction”; 534,490, filed May 2, water channels, or headers for these portions, 1931, “Fluid cooled superheatei` construction”; need be located outside the boiler itself, and in 590,108, ñled February 1, 1932, “Superheater as which the superheated steam is discharged at a ' l'. sembly”; and 699,541, ñled November 24, 1933, “Superheater construction”. A further aim of the present invention is to provide an improved superheater particularly suited for installation in fire tube boilers of the -»' .f locomotive type. It has been the common prac tice, in the installation of superheaters in such boilers, to place superheating elements in certain of the lire tubes, which are enlarged to receive them. Such superheaters work by convection, and since they are not exposed to radiant heat, and since the rate of possible heat absorption is very much less when convection is relied upon, a relatively very large superheating surface must be used, and this method of installing the super »„. heater elements accordingly detracts from the efûciency of the boiler by unduly reducing the number of ñre tubes eiïective to assist in steam` generation. My invention therefore also compre hends so installing a superheater in such boilers as to offer no material obstruction to or reduction ofthe effective number of ñre tubes. Still another object is the development of a superheater installation having an active portion disposed directly within the fire box of such a fire i. tube boiler at a point subjecting it to radiant heat at a relatively higher temperature than the tubes could withstand if empty, and the componentY units of which are so operated and designed as to be guarded against damage by overheating when empty of steam. ' Still further my present invention aims to so arrange a water cooled superheater within the fire box of a ñre tube boiler as to provide a support for baffling means calculated to increase the length of the path of gases of combustion andv flame travel, and to replace or partly replace the conventional water tubes now ordinarily employed for that purpose. Yet another object is the provision of an im ì proved structural arrangement of such a super heater _in a ñre tube boiler, in which the com ponent superheater elements project through leg Vwaiter walls of the boiler which form the ñre box, yet are so arranged as to reinforce and strengthen Cil ' .j the leg walls. point so close to its destination as to enable the use of even shorter steam pipes than are em. ployed in a non-superheated locomotive boiler. Other objects and advantages will be apparent from the following description, wherein reference is made to the accompanying drawings illustrat- ` ing preferred embodiments of my invention and wherein similar reference numerals designate similar parts throughout the several views. In the drawings: Figure l is a somewhat simplified and diagram matic vertical section of the fire boX and adjacent rear portions of a ñre tube locomotive boiler, showing an illustrative installation of one of my improved water regulated superheaters. Figure 2 is a plan view of the superheater as sembly, taken substantially on the line 2_2 of Figure l and looking in the direction of the ar rows, partly broken away and with the boiler and baiiling arch portions omitted to añord a better view of the superheater. 30 Figure 3 is an enlarged transverse section of a header and the extremities of one tube assembly, taken substantially on the line 3_3 of Figure 2 and looking in the direction of the arrows. Figure 4 is a cross section of a tube assembly taken substantially on the line 4_4 of Figure 2 and looking in the direction of the arrows. Figure 5 is a longitudinal sectional elevation of a locomotive boiler construction equipped with a superheater incorporating my invention in some 40 what modiñed form. Figure 6 is a horizontal detail section taken sub stantially on the line 6_6 of Figure 5 and looking in the direction of the arrows, and Figure 7 is a view similar to Figure 4 of a modi ñed tube assembly. Referring now to the drawings, and particularly first to Figure 1, which will be seen to illustrate somewhat conventionally the rear portions of a locomotive boiler typical in many respects, refer ence character I 0 designates the main shell, from which the crown sheet I2 is supported in the usual or any desired manner, as by crown stays I 4, to define a ñre box I5. Forwardly from the fire box projects the main boiler section I6, con 2 . 2,104,937 . taining íire tubes, as Il, while leg Walls, as 20-2 I , jacket the ñre box, the leg 2t constituting a down ward extension of the front Wall, while the leg 2| defines the rear wall of the iire box; all in known manner. It is desirable'that a bañiing arch, as 2l2, of ñre brick or the like, be supported in such posi tion within the fire box as to force the burning and burned gases to double back and pass there 10 around. Such arches' have in the past been car ried by water cooled supports constituting water tubes connected to the iront and rear leg walls and serving to assist in steam generation. Steam generated in such water tubes, of which there 15 are ordinarily not more than five or six, is de livered, in the conventional constructions re ferred to, into the main boiler I6, and collected with the remainder of the steam developed in the boiler in a steam dome as 25, whence it was 20 either conducted through a dry pipe and‘to the cylinders or delivered to a superheater of one of the types previously used, ordinarily housed with in certain of the fire tubes, as stated. In carrying out my »invention` I replace both 25 of the usual elements last discussed, that is the superheater units within the fire tubes and the water tube arch supports, by water regulated superheater assemblies each consisting of a cen tral Water conduit portion 30 and a plurality of 30 circumferentially disposed steam tubes 313 as sembled and contoured in the manner indicated in Figures 2, 3 and 4. As shown -in Figures 3 and 4, the central water tube 3B is preferably provided with a smoothly cylindrical interior sur 35 face to facilitate cleaning, while its external sur face is provided with flutes defined by radially projecting ribs 35. The ribs are preferably heli cally disposed about Vthe >exterior of the tube as shown in Figures 1 and 2, and the channels be 40 tween the ribs are curved conformably to the radius of the steam tubes 33, which are ñtted thereinto and welded in place, as at 36. -A plurality of such water cooled superheater conduit assemblies, five being shown, are extend 45 ed across the rire box, preferably from front to back and at an angle to the horizontal, each as the open ends of the extensions 3l, so that the latter open thereinto, the water header being welded to the steam header along its edges as at 45 to form a semi-cylindrical enclosure. Steam header 42’ constitutes the inlet for Ysteam to be superheated, which is delivered thereinto through a dry pipe lill from the steam dome 25. The dry pipe may, as shown, beV projected through the boiler between the main shell and the crown sheet and connected to the steam in 10 let header 42’ at the rear of the boiler. The cooling water is preferably fed to the assembly through a take off pipe til, tapped into the bot tom of the boiler and connected to Water inlet header 44, while the offtake 48 delivers water 15 and steam generated in the water tubes from outlet Water header 44’ to the boiler, within and near the top `of which it discharges, as shown in `Figure l. From the steam outlet header 42 a pipe, as 5i), may conduct the superheated steam 20 to the cylinders (not shown) or other destina tion. The inflow of cooling vwater is preferably throttled by means of an inlet valve, as 52, adapted to so regulate the admission of Water 25 that the effective level thereof may be held at any desired reduced point Within the .zone of heating. Preferably 'thermostatic ,controlling means as 55 is Aprovided connected to the valve, as by conduit 54, and arranged to open the valve 30 and so raise the water level upon a rise of super heated steam temperature above a desired point, and close the valve to depress the level upon a fall of such temperature. Preferably a manually operable bypass is arranged around the thermo 35 static valve, as at 59, so that when no steam is flowing to control the thermostatic valve the Water tubes may nevertheless be flooded, to pro tect the dry steam tubes, by opening the hand bypass. It will be obvious that the mechanical 40 arrangement of these and other lparts may be varied in many ways. It will also be understood that the generation of steam within the Water tubes 30 in combination with the throttled inlet makes possible »maintenance of a depressed level. That is to say, while the presence of rising -steam sembly being projected through îa bushing, as 40, bubbles ofl increasing size involves the presence extending through and `flanged on 'either side of» of entrained water throughout ordinarily the full one of the leg walls 2û--2l to seal it therein. The bushings 40 and their l»securing ïaïnd sealing flanges are preferably sufficiently heavy >to ma terially strengthen and reinforce `the plates form ing the jacket walls, thus not only compensating for the weakening eifect of the apertures through which the tube assemblies project, but serving as reinforcing elements similar in action to 'stay bolts. The assemblies may be slidable in the bushings to provide for expansion and contrac tion. 60 ' - The ends of the tube assemblies project beyond the leg walls and into transverse front and rear header assemblies 42-44 and 42'--44' respec tively. The steam header portions 42-42’ -are shown as of rectangular section, as indicated in 65 Figure »3, and apertured along their facing Walls to receive the open ends of the steam tubes 33 as well as the central water tube of each ele ment. To the vcentral water tube 3D of each element a projected extension 3l is 'attached 70 which extends across and through the opposite wall of the steam header, in which it is'of course sealed, and opens into a water header 44 or 44” shown las 'carried by vthe wall of 'the steam header and formed of a half tube extending 75 along the-outsideV of the farther wall and over height of each tube, so that the level may not be ’a 'sharply defined one, and some heat absorb 50 ing power arising from the presence of Water may exist all the Way to the top, there is never the less a definite and controllable though grad ual reduction of heat absorbing capacity from the bottom to the top of the active portion of 55 the pipe, and such a throttling of the Water inlet that gravity in effect maintains a reduced level in the water tubes. The presence'of some entrained water all the way to the top of the tubes, however, is a valuable safety factor under 60 extremeV conditions, as it is sufficient to safe guard 'the tube. Y VIt will be understood that the throttle valve 152 actually constitutes an expansion valve, since below it the pressure is greater than above by 65 reason of the head of water in the boiler, the pressure in the steam tubes of the superheating elements above the valve being less by reason of the reduced quantity of liquid, and the free evap oration of suchy liquid which there takes place. 70 By _reason of such free vaporization of the throt tled quantity of water, only gravity tends to -hold the 'water in the bottoms of the steam channels. A sharply defined water level is thus avoided, and the presence of some entrained iwater 2,104,937 throughout the steam tubes assured by the rising bubbles of the rapidly boiling Water. ' Preferably a continuously rising gradient ob tains throughout each water channel from its in let until the discharge is reached; that is to say that while a downward discharge may be used, there are no return bends providing rising gradients after a falling gradient, and all possi bility of water traps and steam pockets is thus 10 eliminated. Upon an inspection of Figure 4 it will be seen that the welded areas 36 form the only integral metallic connection between the water and steam tubes 35i-33, and therefore the only heat bridge 15 through which any rapid heat transference can take place. The heat-bridging welds 3% will be seen to be arranged at the surface of the as sembly in such fashion as to assist in the con duction of heat to the steam within tubes 33 in 20 sections of the assembly containing virtually no water in central tube 3D, while Where or when water is present in the central tube, the tendency of heat to flow to the coldest object and the rela tive physical lengths of the heat paths between 254 the steam and the outside of the assembly on the one hand, and the water and the outside of the assembly on the other, renders the latter path shorter than the former in terms of ease of heat flow, so that heat is removed from the outside 30 of the assembly before it can reach the steam, and the walls of the steam channels are prevented from rising above a desired temperature. Be cause of the absence of a direct integral radial bridge between the water and steam channels, 35 however, water and saturated steam in the former channel cannot desuperheat the steam in the lat 3 spiraled assembly of integrated steam tubes 33a and a central Water channel portion which is in this instance fabricated of a plurality of chan neled plates 30a curved conformably to the tubes 33a and extended sufficiently far to project be 5 tween and space apart each two adjacent steam tubes and provide exposed edges adapted to be secured by the same welds 36m which secure the tubes. The plates 30a, by Virtue of their Welded integration with the surface of the assembly serve to conduct heat directly from the outside to the water where present on the one hand and on the other hand to so greatly restrict as to virtually prevent direct heat conduction between the steam and water conduits by reason of the insulating eñect of the schisms or planes of cleavage bc~ tween the plates and tubes. The operation and characteristics of the assembly may be substan tially the same as those of the form first de scribed and shown cross sectionally in Figure 4. The lire tubes of a lower bank, as lla, are formed large enough to receive the forward ends of the units, which are extended therethrough and project into the smoke box 6B near the bottom thereof. The section of each unit which 25 projects rearwardly into the fire box l5a from the bulkhead 6| is disposed at such angle as to properly Support the balliing arch 22a, and is y looped around the rear edge of the arch and again projected forwardly through the bulkhead 6| near the top thereof. Each unit so projected through the bulkhead may be sealed therein, as by means of the sleeve 11, to which it is Welded, while the looped U-sections preferably terminate just inside the bulkhead, at which point each is coupled to an extension as 'I8 serving to connect ter by absorption directly through the walls. it to headers 42h-Mb, the former constituting The methods of calculation of rates of heat trans ference and relative lengths of heat paths in pro 40 portion to relative temperatures, being well un derstood in the art, they need not be set forth tube discharge header. The headers 42h-44h here, the important consideration being the pro portioning of the fins 35 and positioning of the may be assembled in a manner generally similar 40 to the headers ¿l2-44 previously described, and of the superheater is only that above the effective similarly connected to the component tubes of the extensions 'i8 of the superheater units. The header assembly is preferably located at a high point, partly or entirely within the dome 25a, as shown, and the inlet to the steam header may be controllable by the throttle valve ‘I0 of the engine. The tubes of the extension '18 need not be spi raled since the considerations which motivate the spiraling within the ñrebox (i e., equal ab~ 50 sorption of radiant heat) are here not present. The discharge from the water tubes 3Q may be water level, while the parts are so proportioned that below such level substantial equilibrium is ing from outlet header ¿4b and bent downwardly welds 3E in such manner that despite the outer 45 disposition of the steam channels, the water takes the excess heat from the outside Walls when and Where present in substantial amounts, (and not merely entrained with bubbles) thereby prevent ing the heat from reaching the steam and guard 50 ing against over superheating in such areas. Generally speaking, therefore, the active portion 55 maintained, so that steam passing downwardly therethrough is not desuperheated, although it cannot obtain more heat to be additionally super heated. To preserve equilibrium and prevent de superheating outside the zone of heat absorption, 60 the welded joints 35 are preferably terminated at the boundary of the Zone of heating, as indicated in Figure l at 35’. In Figures 5, 6 and 7 a somewhat modiñed ar rangement is shown in which no steam inlet or 65 Water tube outlet headers, or other connections, need be arranged within the cab, and wherein sat urated steam is delivered to the superheater di rectly at the dome and within the boiler, while the water tubes also terminate and discharge 70 within this portion of the boiler. In this con struction the superheated steam discharge is at the smoke box end of the boiler and close to the steam chests„so that long delivery pipes are also unnecessary. 75 the steam inlet header and the latter the water , The superheater umts are shown formed of a through one or more outlet pipes as 38h emerg to discharge above the water level in such man ner as to both guard against the splashing or surging of water into the water tubes and prevent the discharge of saturated steam and entrained water into the dome. 'I‘he forward extremity of each superheater (50 unit is connected to a header assembly comprising steam outlet and water inlet headers ‘32a-«34a respectively, shown as arranged within the smoke box 60. The water header 44a through which the water tubes 30a of the superheater units are supplied with water from the boiler is directly connected to the forward end of the boiler by water inlet pipe 41a., while the ñow through the latter and so the effective level in the Water tubes is controllable by an inlet valve 52a, by which the Water supply may be throttled. The operation of this valve may be similarly controlled thermo~ statically in response to the temperature of super heated steam, as by the thermostatic means di agrammatically illustrated at 54a, while a hand 4 2,104,937 operated bypass may be provided for like rea sons, as at 59a. From the header 42a the super heated steam may be conducted directly to the steam chests through steam pipes 15, shown as extending within the smoke-box, though this is of course entirelyoptional, and outside connections might be used if desired. » In this construction also the steam is made to flow downwardly through the units during super heatíng, saturated steam being collected from the drum directly at the throttle valve port in the dome, Which serves as a take-off and is directly connected to the inlet header 66, by which it is shown as carried. The- only access to the super heater tubes 33 is thus arranged Well above the water level and within the steam dome in a posi tion eüectively guarded against splashing. The bridging welds 36a are preferably provided only within the zone of radiant heat absorption, Y20 and terminate substantially at the boundary of such zone. This is particularly important at the outlet end of the assembly to prevent desuper heating of the steam. At the upper end of the assembly the termination of such welds is of 25 course a matter of no consequence, since the steam and water tubes are here at substantially cluding ñre tubes connecting said ñrebox and smoke box, said boiler also being provided with a collecting dome for saturated steam Vlocated above the Water level, a superheater assembly comprising integrated steamV and Water conduit portions looped through the ñrebox and termi nating at their upper extremities appurtenant the dome, said steam conduit portions having in let means within the dome, the water conduit portions having chscharge portions above the water level, at least the steam conduit portions oi said assembly extending through the ñre tube portion of the boiler and having discharge por tions` appurtenant the smoke box, and control lable water inlet means for the lower ends of the water conduit portions. . ~ 2. In a locomotive construction, in combination with a fire tube boiler having a ñrebox at one end and a smoke box at the other and including iire tubes connecting said fire box and smoke box, 20> said boiler also being provide-d with a dome lo cated above the water level for collecting satu rated steam, a superheater assembly comprising integrated steam and water conduits terminating at their upper extremities appurtenant the dome, the steam conduit portion having an inlet with the same temperature. At the lower end of the assembly the line of termination of the bridging in the dome. welds is designated 36o. The operation of this form of my invention will be seen to be quite similar to that previously described. The admission of water to the steam ing a ñrebox portion and having a collecting dome for saturated steam, a water regulated ra 30 channels is so controlled as to hold the water .at reduced eifeotive level, vand to vary the `effective superheating surface, while the design of 'the tubes is such as to perform the interprotective function previously discussed. It will be understood that the lower ends of the looped units might be projected through the 40 water leg 20a after the manner of the ñrst em bodiment, if desired, and that the continuation thereof through the lower flues I'la, while af fording some additional heat absorption, is of convenience particularly because affording de livery of steam at a point close to the chests. The ilues Ila, or if desired only the units Within them, may be inclined upwardly somewhat to insure the proper flow of steam generated in the water tubes. If the superheater units are grouped 50 so closely in order to enable them to pass through a lower portion of the generally cylindrical boiler that they do not bridge the full Width of the fire box, additional support for the arch 22a may be furnished by simple water tubes as 23 arranged therebeside and connected at their forward ends to the boiler or front leg 20a and at their rear ends to back leg `2 la. Although I have shown and discussed a cross ' sectional arrangement of steam and water tubes 60 which I regard -as preferable, it will be under stood that changes may be made without de 3. In combination with a firetu‘oe boiler hav diant superheater assembly comprising inte grated steam and Water conduits extending through the fire box portion and to a position appurtenant said dome, the steam conduit por tions having an inlet Within the dome. fi. In combination With a nre tube boiler hav ing a ñrebox portion and having a collecting dome for saturated steam located above the Water level in the boiler, a water-regulated radiant su perheater assembly comprising integrated steam 40 and water conduits extending through the ñre box portion and to a position appurtenant said dome, the steam conduit portions having an inlet Within the dome and the water conduit portions having an outlet also arranged above the water level. ' 5. In combination with a ñre tube boiler hav ing va ñrebox portion and having Va collecting dome for saturated steam located above the Water level in ‘the boiler, a water-regulated radiant su perheater assembly comprising steam andA water conduits having metallically integral portions extending through the ñrebox and being extend ed from said ñrebox through the boiler portion and at least a portion of said assemblybeing pro jected into the dome, said steam conduit portions having an inlet within the dome, and the Water con-duit portions having an outlet also located above the water level. 6. In combination with a ñre box and a fire tube boiler including water containing portions parture from the spirit of -the invention, which is defining Wall portions ofY the fire box, and ñreV to be limited only by the scope of the subjoined tubes extending from said ñre box through one claims. `Under extremely high ratings, for ex-v of the water containing portions, steam collect 65 ample, it might be advisable to» run the steam ing means for said boiler arranged above the through the inner tube and the »water throughV water level therein, and a superheater compris the outer tubes. Whether the steam iiows up or ing a plurality of assemblies of water and steam down the unit will be seen also to be a matter of choice, as lis also the use of boiler Vwater rather tubes, said tubes of each assembly being arranged than an external source of supply for the cooling for ready heat transference with one another, 710. extending from said water-containing, and wall tubes. portions and through said ñre box, the water What I claim is: tubes of said assemblies being regulably Ycon 1. In a locomotive construction, in combina tion with a iire tube boiler having a i'lrebox at nected to a water-containing portion of the boiler and the steam tubes Athereof extending through 754 one end and a smoke box at the »other and in 2,104,937 but being unconnected to the Water containing portions and being connected to the steam co1 lecting means. 7. A superheater construction as set forth in claim 6 in which said fire box has a bañiing arch therein, and said Water and steam tube assem blies support said arch. 5 8. A superheater construction as set forth in claim 6 in which the water and steam tubes of said assemblies are helically intercoiled and inte grally connected, and in which said fire box has a bafñíng arch supported by said assemblies. CHARLES S. TURNER.