US1848130A

US1848130A - Air heater

Info

Publication number: US1848130A
Application number: US230737A
Authority: US
Inventors: David S Jacobus
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1927-11-03
Filing date: 1927-11-03
Publication date: 1932-03-08
Anticipated expiration: 1949-03-08

Description

AIR HEATER Filed Nov. 5. 1927 4 Sheets-Sheet l w i a \Q Sq &

1: I hi1 A 1/ INVENTOR BY 'J ATTORNEY$ March 8, 1932. D. s. JACOBUS AIR HEATER Filed Nov. 3

4 ShQetS- -Sheet 2 W/ INVENTOR ATTORNEYS March 8, 1932. 5, JACQBUS 1,848,130

AIR HEATER Filed Nov. 3, 1927 4 Sheets-Sheet 3 Fig- 3 mZ/ZZ/ INV NTOR AWQRNEYJ WWIM March 8, 1932.. 5, JACQBUS 1,848,130

AIR HEATER Filed Nov. 3. 1927 4 Sheets-Sheet 4 2 INVENTOR I ATTORNEYS Patented Mar. 8, 1932 it 1, :nnvrn sLJAco us. ornoiircmln, New JERSEYQASSIGN R use-ism iaiiiicocka wired: V j

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"gap iiea'u zi filea n embrs, 192% serial 11 2303371 This invention relates to an air heater and I is a division in part ofmy application Serial" No. 571,919, filed June 30,- 1922 which has maturedfinto- Patent #1547397, [da'ted No-g ve'mber 8; 1927 The invention will be underej stood from the descriptionin connection withthe accompanyingdrawings, in which Fig.

1 is a vertical section through an illustrative embodiment of the invention;'Fig. 2is a lo perspective view on an enlarged scale showing someof the details"; Fig. 3 is a vertical see- I tion through a modificatiomand Fig; 4 is a perspective view showing some of the details ofFigL3.

5 of the well known typeythe hot gases from which pass through'a gas outlet Sand down wardly over an economiz'er'7 into a flue 8., From this flue, the hot. gases pass upwardly throu h afiue 9 aroundthe air heater; which is to e described more specifically herein In Fig. 1, I have illustrateda steam boiler by two platesspacedapart a distancethat iSj small in proportion to thewidt-h of the plates;

andlthefwi dth' is small proportion to the length; I The spaces between such tubes forni passages which are similar in shapeandgeneral proportionsto the tubes. The'space'sbea tweenthe upper ends offpairs ot plates 2O' and 21 are closed'by horizontal strips 25 and thespaces- 'between these strips 25-are left open; Alter nate spaces between the lower; j beveled ends of the plates and 21 "are closed; g I by inclined closure members 26, so'that' the olosures and-26 at opposite ends of the plates are stagger'ed'with respect to each" other. The spaces between the plates 20 and 21 in the respective ducts-9 and llare closed .by strips 27 along the central plane ofthe 7 air heater'and alternate spaces between'the'se plates 20 and 2 1 are left openfor a short dis; tancebelow'the-strips 25 so that air can pass air-heater, the air flowing upwardly through 3U" the-ducts oftheair heater and then across'a" below the strips 25 from one'duct 11 to the V other'duot 9. a "i lhe spacesbetween the edges of the plates 21 an'df22 near the lower ends are left open after, passing at thetop'thr'ough across flue lOwhich may be of the form illustrated, and then downwardly through a verticalflue 11 I V p a: to a gas outlet' fiue 12 which is con'nected in for sdme' distancei "as shown at, 28, corre-y the form illustrated tofa fan 13 bywhich the I spondingtc the opensp cesbetwee t e s r ps gases are'forced' toa stack 14. 25 -at the-top-,"sothat gases enter 'theair A fan 15 forces air through avflue 16 intoftheto" the longitudinal axis of the ducts and pass so;

horizontal connection, which will be described more fully hereinafteminto'the second set'of V air ducts throu h'which the airpasses down-- Wardlyto analr'outl'et flue or duct17 from which itmaybe supplied to a combustion chamber through an 'underfeed' stoker 18",

which I have adopted'for purposes of n n 1 t ti fi; V

In the formillustrated, as inore'clearly shown in Fig.2, the airiductsareformed, of

metallic sheets placed side. by'side with the spaces between their edges closedto form gas tight joints; In the form illustrated in Fi'g.

f 2, each duct is made up of a; flat sheet metal. plate 20 and a similar plate 21 having its edges bent, as shown at 22- and 23 to provide'aspac ing portion and a fastening portion,"the portion 23 being riveted to the edges of theplate u 20, as "shown at This constructionforms flatt'ubes'spaced apart; Each tubeis formed between thefstri'ps '25'into the cross fluelO,

thence downwardly between corresponding plates in the duct 11, and thence outWardIy through the spaces 28. A pocket 29 (Fig; I) I belowtheoutletfi is so located andshaped 85,

as" to provide 'a reverse -bend;for7thegases, with theresult' that the'gases enter'the heater .in such'a direction that theywill bewelldis tributed across the spaces between; the plates without-crowding too. inuch to one side and leaving inactiveportions. 'The gases fi'owin downwardly over-the economizer 7 an through the flue impinge against the lower inclined wall of thedust hopper'29 and are deflected upwardly in 'such away that the gas stream makes a less 'angle'withthe' longest center line-"of the passageway in thefiuid heater than does the inclined wall opposite 'the opening thro'ugh which the gases enter;

As the gasesfloiw upwardly from" the bottom 7 idO of the hopper 29, they assume a generally fan-shaped form, the axis of which more nearly approachthe longest center line of the heater than does the wall opposite the entrance opening. This construction causes the gases to be evenly distributed across the passages from front to rear of the air heater; It will be apparent that where the gases are introduced at a right angle tothe longest axis'of-the air heater, then the gases pile upagainst the wall opposite the opening against which the gases are introduced, with the result that there is an unequal distribution'of the mass flow of the gasesthrough d flerent portions of the passage wh1ch leads to a less eflioient heat. transfer than in the case of ap plicants device where the gasesare evenly,

distributed. Also the air entering through the inlet. 16 is traveling in-the direction it will-take in passing through the spaces in the duct 11; a

vIn the modificationshown iirFigs. 3 and i, the gases from the economizer 7 passthrough the pocket 29 andthence enter the air heater 30 that is provided withhorizontally extending spaced plates, as shown in detail in Fig.1

4. The upper and lower edges of the

plates

31 and 32 are bent so as to contact with each other, as shown at 34, in pairs, thus leaving spaces between the pairs for the passage of the hot gases and spaces betweenthe plates ofthe pairs for the passage of air to be heated. The hot gases are caused to enter in the directionof the longitudinal axis of the air heater,

so that there is good distribution of gases withoutgcrowding to one side and the air is also caused to enter in a similar manner from,

the other end of the air heater. The spent gases pass at one end air passes out through spaces 36 alongthe opposite side at the other end of the air heater.

iL-In an air heater, flat tubes and spaces between them torming passageways for air andla heating gas, respectively, means for diresting-one of the fluids into said passageways substantially in the direction of the longest center. line of said passageways, and aninlet opening for the other fluid in theside of the heater, the wall of said heateropposite said opening being inclined to said longest center line, the angle between the stream flow otthe other fluid: through said opening; and said longest center line of said heater beingless than that between said wall and said longest center line.

2. In an air heater, flat'tubes and spaces between them forming passageways for air and a heating gas,respectively, means for di recting oneof the fluids into saidapassageways substantially'in the direction of the longest center line of saidpassageways, an inlet openingfor the other fluid intheside of the heat v thedirectionof the longest center line out through spaces 35 ;onone side of the air heater andthe heated '3. In air-air heat "r, 'flattubesand spaces be tween them forming passageways for air and i a heat ng gas respectively, means for directing" one of said fluids into its passageways in of said passageways and an inlet opening for the other fluid inthezside ofthe heater, thewall of said heater opposite said openingbein'g inclin'ed' to said longest; center line, the anglebetween the stream flow of the-other fluid" through said opening and said longest center line of saidzheaterbeing less than that between s'aid wall and said longest center" line, with said fluidsflowingcountercurrenta 4C. In anair heater, flat tubesand spaces be tween them tormingpassageways for air and a heating gas, respectively, means for directlng one of saidfiuids into-itspassageways 11L the'direction of: the longest centerline of said passageways and an outlet openingifor the other fluid in the side of the heater,the wall of said heater opposite said opening; being inclined to said longest center1ine,the angle between the stream flow of the other fluid through said opening and said longest center? line of saidheater being less than that between, said wall and said longestcenter line, with said fluids flowing" countercur-rent, said last named means comprising apocketlocated' near the entrance tosaid passageways '5. In an air heater, flat tubes andspaces between them forming passageways for air and a heating gas, respectively,- means for directing one 1 of said. fluids into its passageways in the direction of theilongestvcenter line of said: passageways and: means fordi? recting the. other fluid into its passageways-I substantially in the opposite direction along;

said center line, with saidfluids-flowingcountercurrent,sa1d last named meanscomprising a pocket located in the portionofthe flue ap-- proachingsaid air heater 6. In an air heater, flat tubes andspaces:

between them tormingpassageways for air andal heating gas, respectively, meansfor directing one of the fluids into said passages ways substantially in the direction of the;

longest center line thereof, and means comprising a dust hopper located: in the flue apiproachingsaid air heater for deflecting the stream flow of the other fluid and causing it to enter the air heater substantially. in thedirection of the longest center line vor said-passa eways.

tweenthem forming passageways for air and a. r In an-a1r heater,'flat tubes andspacesbe I ing inclined to said longest center line, the

' fluid through said opening and said longest center line of said heater being less than that a heating gas, respectively, means for direct ing one of the fluids into said passageways v I substantially in the direction of the longest center line thereof, and an inlet opening for the other fluid in the side of said heater, the

wall of the heater opposite said opening beangle between the stream flow of the other between said wall and said longest center line.

8. In an air heater, flat tubes andspaces be- Y 1 tween them forming passageways for air and a heating gas, respectively, means for.direct-f;

ing one of the fluids into said passageways substantially in the direction of the longest I center line ofsaid passageways, means for directing the gases over the heating surface of a steam boiler'and then through an inlet opening in the side of the heater, the wall of the heater opposite said opening being inclined to said longest center line, and a soot hopper located in the portion of the flue V where the passages approach the air heater for directing the gas stream flow substantially in the direction of the longest center line of said passageways.

DAVID 's. JACOBUS. j; g i