Патент USA US2116546код для вставки
May 10, 1938. ‘ Q c. 5. SMITH ‘ FLUID HEAT 2,116,546 EXCHANGE ‘APPARATUS ' Filed March 29, 1935 3 Sheets-Sheet 1 Fig: 1' 92 24 70 ,2- /30 ' ’ I 3‘ ' , 2 20 700. ‘ 2'2 ‘ 80 ‘ INVENTOR Charles S. Smz‘z‘h ' B mm 7 ATTORNEY May 10, 1938. c. s. SMITH 2,116,546 FLUID HEAT EXCHANGE APPARATUS Filed March 29, 1935 5 Sheets-Sheet 2 o?wo 00 000 0 0 0 0 0 0 0 0 0 0 0 0 000 0 gm aw a?v Gag Q INVENTOR (IGarLaS‘SISYHiih B AT gggEY May 10, 1938. E Q s, sMn-H - - 2,116,546 FLUID HEAT EXCHANGE APPARATUS Filed March 29, 1935 3 Sheets-Sheet 5 4 38 48 46 68 30 F1573 F4 Ill/11111014 INVENTOR Charles 5 Smii/z I B @RW . AT ORNEY‘ 2,116,546 Patented May 10, 1938 UNITED STATES PATENT OFFICE 2,116,546 FLUID HEAT‘ EXCHANGE APPARATUS Charles S. Smith,‘ West?eld, N. J ., assignor to The Babcock & Wilcox Company, Newark, N. J ., a corporation of New Jersey Application March 29, 1935, Serial No. 13,694 3 Claims. (Cl. 122-480) superheater. creased superheat, but this may be prevented, and a constant superheat maintained, in the il lustrative apparatus, by control of the ?ow of the gases passing over the secondary section of the It is an object of the invention to provide for the regulation of superheat over a wide range this control will now be described. This invention relates to fluid heat exchange apparatus, and it is exempli?ed herein as an em bodiment of a water tube steam boiler with a r. of boiler capacity. It is an inherent characteristic ‘of some super‘ heaters that they produce a variable superheat This 10 in response to changes in boiler ratings. is particularly true of a superheater which is mainly heated by convection transmitted heat. This is an undesirable condition in modern steam power plants, and it is a further object of this invention to provide means for overcoming this defect. Other objects of the invention will appear in the accompanying description of the superheater boiler shown in the drawings, in which: 20' Fig. l is a view in the nature of a vertical sec tion through the steam boiler and superheater installation. Fig. 2 is a view in the nature of a partial verti cal section taken on the line 2-2 of Fig. 1. Fig. 3 is an enlarged view in the nature of a vertical section of part of the structure indicated in Fig. 1. Fig. 4 is a detailed vertical sectional view of a part of the control mechanism, taken on the line 30 4-4 of Fig. 3. In the drawings, there is shown a superheater H) of the multiple loop type. It receives satu' rated steam through the supply conduits l2 and the inlet header I 4 from the steam and water drum l6 of the boiler and is contacted by the fur nace gases after they have passed across the bank of horizontally inclined steam generating tubes l8. The boiler shown in the drawings is substan tially a single pass boiler, whereas the superheater may be said to- have a primary section and a sec ondary‘section subject respectively to contact with the furnace gases in di?erent gas passes. The superheater baffle 20 separates these gas passes. superheater. The apparatus shown for elfecting When boiler capacity increases, the gas de~ flector, shown as pivotally mounted at 26, may be moved toward its dotted line position indi cated in Fig. 3. Such action provides another path for the gases leaving the first section and one of less resistance than that across the sec ond section. This reduces the ?ow of the gases passing over the secondary section ofthe super heater and tends to counteract the tendency of the superheater to produce higher superheats at increased boiler ratings when all of the gases sweep its surface. It will be seen that, as the de?ector 24 is moved toward its dotted line po sition, more and more of the furnace gases may pass directly to the outlet 25 without sweeping over the secondary section of the superheater. The de?ector 24 is controlled from a position outside of the boiler setting, by a mechanism in to cluding a link 28 connected to an arm 30 which‘ 25 is non-rotatably mounted upon the shaft 32. The shaft 32 is rotatably supported in bearings which are preferably formed upon the casing 34. With in the casing there is shown a worm wheel 36 ?xed upon the shaft 32 and arranged to be driven 30 by a worm 38 journaled in the casing and having a handwheel 40 ?xed thereto at its end. > The shaft 32 may, as indicated in Fig. 2, be connected to extension shafts 42 and M so that a number of the deflectors may be operated in 35 unison. Fig. 2 shows an illustrative construc tion in which there are two control mechanisms, each extending halfway across the boiler instal lation. Fixed to arms iii are counter-balancing weights 48 which facilitate the operation of the control mechanism. As indicated in the drawings, the links 28 are located between the horizontal circulators 50 and 52, and they pass through openings 5d and 56 pro vided in the gas con?ning walls of the boiler. At the left of the balile 20 shown in Fig. 1, . These openings ‘are wide enough to provide for the swinging of the links 28 from their full line the primary section of the superheater is sub ject to contact with the furnace gases leaving positions to their dotted line positions as indi cated in Fig. 3 of the drawings, and to maintain the water tube bank I8. After the gases have been progressively cooled by passing over the the opening 56 substantially closed during the 50 operation of the control mechanism, cover plates tubes of this section they normally pass down wardly at the rightof the baffle 20 and over the 58 are provided. These plates slide in guidewa-ys provided by guides 68 and ,62, and are formed secondary section 22 of the superheater. As boiler ratings increase it is the tendency of with openings M through which the links 28 are Ur in . superheaters located as here shown to‘ give in passed. Indicia 66 provided upon the casing 34 2 2,116,546 coact with the indicators 68 to show the positions of the superheat control mechanism. the circulators 50 and 52. On the gas side of the portion 84 of the circulator, the tubes of each of When the de?ectors 24 are in their full line these upright rows are bent so that they form a single horizontal row of superheater tubes as in positions indicated in Fig. 3, a maximum weight of furnace gases passes over the secondary sec dicated at I22. tion 22 of the superheater. In this position the de?ectors cooperate with end ba?‘les herein shown continue in successively lower horizontal rows to as plates ‘Ill secured to the superheater tubes or loops. The major portion, and if desirable, all 10. of the furnace gases pass between the wall ‘H1 and the ba?le 2d at low boiler ratings. The top of the wall 10 is preferably below the top of the bank of tubes Ii). Furthermore, it will be noted that the control mechanism including the de?ectors 24 15 and the plates 10 are positioned in zones where the gas temperature is lower than elsewhere. This arrangement promotes the durability and long life of the control apparatus by preventing excessive overheating. 20 The particular steam boiler shown has down take headers ‘I2 connected at their lower ends to a mud drum 14 and at their upper ends to the water space of the drum I6 by downtake nipples 16 which are offset as indicated at 18 and 80 to 25 afford a minimum resistance to the passage of gases to the outlet 25. The downtake headers are connected to uptake headers 82 by the steam gen erating tubes I8 and the former are connected at their upper ends to the steam space of the drum 30 I6 by the horizontal circulators which have the upright portions 84. These portions may be said to be uptake nipples. The uptake headers are preferably pendently supported by hangers 86 Thence the superheater loops the lowermost row I24 from which horizontal row the tubes are bent to form vertical rows of tubes I29 connected to the inlet headers I4. The downtake headers of the boiler may be 10 pendently supported by the nipples 16 from the drum I6 which is secured in a well known man ner by strips secured to the structural frame work. In order that the superheater tubes may be subject to a desirable gas distribution and gas contact, tile I31] are supported upon some of the tubes and preferably positioned between the up right rows which are spaced to accommodate the tubes 94 and IE6. The drum I6 may be supplied with feed water in any suitable manner, and the outlet header I I2 of the superheater may be appropriately con nected to apparatus which makes use of the su perheated steam. The furnace has walls I32 and I33, the latter of which includes wall cooling tubes I34 connected into ?uid circulation by any suitable devices which may include the upper header I36. Not only does this invention involve means for 30 obtaining a close control of superheat over wide temperature ranges, but it also accomplishes this result with a minimum increase in draft when ?xed to the stationary frame structure 88. As shown in Fig. l of the drawings some of the the gases are directed over a second section of the tubes of the uppermost row of steam generating which is transverse to the tubes of the super heater. The superheater is provided with two sections with gas ?owing transversely across the tubes in each section. A damper is provided tubes leading from the downtake headers 12 are connected at their upper ends to a header 90, which is a support for the superheater and which is preferably hung from an overhead beam by the hangers 92 and the auxiliary circulators 94. The latter may be connected to the drum 90 and be positioned between upright rows of the super heater tubes so as to afford an internal flow of 45 boiler water for protecting the baffle 95 against overheating. At their discharge ends the circula~ tors 94 are connected with the steam space of the drum. Fig. 1 of the drawings shows a second super heater supporting header Ill? connected by tubes IE2 to the upper parts of the downtake headers superheater. This is all done with a gas flow 35 which can be made to regulate the amount of gas 40 ?owing over the second section. With this ar rangement, at high loads, the gas bypasses the second section giving a low draft loss through the superheater. At the low loads, where excess draft capacity is available, the gas is forced over 45 the second section to increase the superheat. What is claimed is: 1. In a drainable super-deck superheater for a single pass B. 86 W. boiler, a ?rst baiile extending across the tubes of the superheater and separat- . ing ?rst and second gas passes, a second ba?le ‘I2. Between the header I00 and the row of downtake headers 12 a heat resisting inter-tube space ?ller or superimposed layer IE4 is sup supported by the superheater tubes in the second gas pass and spaced from the ?rst baffle, and a ported by the tubes I02 to form a wall which, in this instance, causes all of the gases leaving the bank of water tubes It to pass to the superheater. This layer may consist of tile secured to the tubes I02. Above the header IIJIJ, wall 20 is cooled by sup— plementary circulators IE6 preferably located be tween upright rows of the superheater tubes and connected at their lower ends to the header Ill. Their upper ends I68 communicate directly with the steam space of the drum I6 and hangers ID are connected to the upper parts of these circu— ,. ?rst and second ba?‘les to limit the opening of the second pass and to vary the total weight of the gases contacting with the superheater tubes in lators as shown. tion of the gases contacting the second part of the superheater in order to maintain constant superheat when boiler ratings vary, said Fig. 1 of the drawings also shows a superheater outlet header H2 supported by hangers H4 de~ 70 pending from the stationary structural member H5 and communicating with the superheater loops through outlet tubes I I8. These outlet tubes as well as the inlet tubes I20 are indicated as positioned in vertical rows with each row lo 75 cated between adjacent upright portions 84 of manually operable damper co-operating with the the second gas pass. 2. In apparatus of the class described, a steam boiler including a furnace and a bank of steam generating tubes, a single bank of superheater tubes, ba?ies compelling the furnace gases to pass over the generating tubes and a part of the superheater in a single gas pass and then pass over another part of the superheater in a second 65 gas pass, and means for varying only the propor superheater including tubes which extend 70 through one of the baffles to form both super heater parts. 3. In a steam boiler, steam generating tubes, a bank of superheater tubes extending across the path of the furnace gases at a position beyond the 75 2,116,546 steam generating tubes, a ba?‘le wall extending across the superheater tubes and joined with a second baf?e wall so extending from a side wall of the furnace as to shield a part of the bank 3 gas de?ector means positioned beyond said re mainder of the superheater and adjustable to control superheat by decreasing the proportion of the gases contacting with said part of the from contact with the furnace gases until after ‘ superheater as the boiler load increases. they have contacted the remainder thereof, and CHARLES S. SMITH.