US2979830A - Rotary pressure vessels - Google Patents

Description

April 18, 1961 R. M. DONALDSON 2,979,830

ROTARY PRESSURE VESSELS Filed Jan. 31, 1956 United. StatesPateiftiJV ROTARY PRESSURE VESSELS Robert M. Donaldson, Hampton, Va., assignor to Newport News Shipbuilding and Dry Dock Company, Newport News, Va., a corporation of Virginia Filed Jan. 31, 1956, Ser. No. 562,465

12 Claims. (Cl. 34-124) usl l ce I 2,979,830`

Parenteel Apr. 1s, 1961 head being joined directly to the shell and the two heads being rigidly joined by anintervening ue. Still another object of this invention lies in an imf proved drier constructed in accordance with the preceding object wherein the slip joint includes a ring-like bearing interposed between the shell and the unanchored head and a sealing ring of semicircular cross section rigidly coni nected to both such head and the shell, the sealing nng being constructed of deformable material to allow for rela tive movement between the head and shell.

The ligure of the drawing is a longitudinal section taken through one form of drier constructed in accordance with this invention. v

. Referring now more particularly to the figure'of the drawing, the form of drier shown thereinv includes an Wouter shell or drum which is of generally cylindrical configuration and which is provided at its opposite open' ends with the inturned flanges 11 and 12. These tw'o flanges serve to provide means by which the two headsf' indicated generally by the reference characters 13 and 14,

are operatively related to the shell. Although the heads,

x'This invention contemplates the use of Yankee driers having a much thinner shell thickness than conventional driers. The thinner shell provides, assuming the same internal steam temperature as for a drier having a thicker shell, a greater rate of heat transfer than the thick-shelled drier. ,This will permit a much' greater rate of production to be accomplished in the paper making industry.

However, a Yankee drier having a shell thickness and diameter of the magnitude contemplated by this in'- vention must depart radicallyin structural detail from 1 those constructions employed in'conventional practice.`

EIt. is therefore an object of this invention to provide an improved form of Yankee drier embodying a thinner shell section than has been heretofore attainable in the prior art.

Another object of this invention is to provide an imv proved drier including a thin outer cylindrical shell closed at-its opposite ends by a pair of heads, the heads being interconnected by an internal line and in which only one o flthe heads is connected directly to the shell to minimize the transfer of stresses between the heads and the shell.

-Another object of the invention resides in the constructionV in accordance with the preceding paragraph in which a-*circular bearing is interposed between the unanchored head and the inner surfaceof the shell to permit relative movement therebetween. IStill another object of this invention is to provide im povements in Yankee driers embodying an outer cylildrcal shell having a ue disposed concentrically with.

in the specific embodiment shown, are illustrated as beingf integrally formed with the flue structure, indicated geni erally by reference.A character 15, 'it' will nevertheless 'bef-1 understood that the heads may be formed as separate members, either in whole or in part, which are secured at their outer edges to the shell and which are also con-j nected to the lluefor locating the same in proper rela-i tion to the shell. The llue as shown consists of three separable parts,

`a pair of identically formed end lsections which 'include inthe shell connected at one end to-the corresponding.

end of the shell by a head portion, there also being a head V with the other end of the flue carrying a ring-like bearing engaging the inner surface of the shell and per-4 mitting relative movement between the other head and the shell so as to obviate the transfer of stresses therebetween, the ilue being of substantial diameter with re,-V spcttoy the shell'and servingl to rigidifythe heads and m'intain the bearing in proper contact with the inner sur- 4 aceoftheshell. Y

the aforementioned heads," and a` centralI section which joins'and interconnects the two end sections. Each'en'cl section incorporates an axially extending and outwardly "f projecting shaft or journal 16 received in suitable bearings' i: as indicated by the dotted line structure for rotatably mounting the drier in horizontal position as shown. lEach su'ch shaft isl hollow and serves as an external connection to one of the two separate internal chambers 17 and 18 within the ueand each'shaftl is rigid withY i or formed integrally with the central or'hublportion"19'. of'its associated llue end'section. Each flue -end section alsol includesl an inwardly 'di-i1'. rected cylindrical portion 20 terminating 'in an outturned i flange '21, which anges -deine the partingy line between the end sections and the central flue section. The central 1 section is in the form of a cylindrical body 22 having outturned flanges 23 and 24 at its opposite ends joined to' the flanges 21 of the end sections by 'means' of suitable fasteners 25. e 's ,Centrally located within the center section is a partition wall or baffle 26 having in the specific embodiment I shown a central opening 27 normally closed Iby the re" movable cover plate 28. Thus, the baflie serves to isolate f: the two previously mentioned chambers 17 and 18. On t Y ,opposite sides of the baille are formed a series of open-:z

Another'object of this invention is 'to' provide' a 'drier i unconformity with the preceding object wherein the 'sh'ell thickness'is in the order of 11/2 inches; the shell diam" eteris inthe order of 'l2 feet; the due diameter -is in the order'of from 60%-75% of the shell diameter; the ratio of.ue thickness to shell thickness is in theA order 'of' rpmfl-25 to l-2.0 to l; and the ratio of head thickness;- to shell thickness is in the order of from 1.5 to l-- 2 .5 to..1. :Afur'ther object of this invention resides in. an im-` proved Yankee drier embodying a slipjoint'.o'nnection.-, between one of its heads and the outer shell, 'the other ings 29 and 30 in the body 22 of the center section so i las to communicate the two chambers 17 and 18 with the? annular chamber 31 formed between the 'flue -and the inner surface of 4the-shell 10. A In use, steam under pressure .is introduced iinto"one ,I chamber through-vthe-corresponding shaft- ,16. whence ther-f steam owsjintoone ofthe chambers 17 0,1118 ,andoutfg wardly thereof through either theopenings29 or 30intocj the annular chamber 31 to Vheat the shell 1 0. The steam is there forced frorrrthq annular chamber 5,;31- in'to .the other fluechamber 17 or 18 'andthence outwardlythrough the `corresponding shaft 16. 'i. :f sa

The end sections of the flue include, i additin togth above mentioned partsythe'gner-allyradiallysexteadiai integrally 'with' meiemam" de: 6r me au'endvm Eachannular portion 32, together with its corresponding central Ys,e,ctio 1r1,19,v constitutes., and presents vwhat may be termed a head for the corresponding end of the shell 10. Additionally, each ue end section may include a number @generally triangular;A radially ,extending reinforcing ribs- 35 joining the annular: head. portion '32 w .hiitsrasscciated cylindricahportllonrl.I

.From the drawing fit; wil;l ;be apparentY that ithe; wall. thickness of;` theY flue structure isyrather: massive. when; compared. with kthe-;w,all.V thickness, offv the shelll and; that;` the d iam eter ofthe fiueis quitelargea. These two fea- .Y tures; cooperate to,renderfthe-Vcentral'l portion v19 of each, head substantially: rigidgbut;morerimportant,` deformation: of the heads atV the juncturel of;thecylindrical portions. ZQ-Oftheue; therewith dueto the internal pressure, of the;v steamf is, practically i non-existentvv and, consequently any deformations of the annular portionszi of vthe heads will; be relatively` small .1 as: compared: with; conventional practice.wherein-A very small diameter uesfare normallyY used. At the Sametime, the annular chamber 31 between the-hue andthe shell isof sucient volume as to allow... evendistribution of heat from the: steam and theA shell, assuring substantially uniform heattransmission .tov the; shell. It is important to maintain the annular chamber 31 v of sufficient radial width as to avoid stratification of theflowing'steam tendingv to create definite flowr paths.` between Ythe ue openings` 29 and 30 which action would result infdead spots within the-chamberv-l and unevenv heat distribution ofthe shell..

The limits` of uefdiameter withlrespectto.: the. shell" diameter` areapproximately- 60%.-75%.'. A; particular Y relationshipqbetweennthe shell wall. thickness and the -flue wall thickness also exists and, in this respect, the fiue-wall'i thickness shouldV ber from 1.25 toI 2.0 timesthefshell thickness., Also, the wall thickness of those portions of the flue-end sectionswhich define the heads should'be from 1.5 rto;2.5,.timesthe shell thickness, the same conditions prevailing when the heads arerpartly or whollyy formed separately and removably..attached to theflue; Y

Whereas the marginal edge 46 ofonehead 13l is rigid- Yly securedxas Yby;- fasteners 47. to itscorresponding shell flangeV 11, the other head 14 is'notfrigidly attached at its marginal edge 48to. the shell. Instead, an annular orv ring-likel sea-l orfbearing.y 49 is interposed between the circumferentialy edge of the. head portion 48 and the inner edge ofthe shell flange 12. Preferably thisbearing is ofiiT-shaped cross section with the'lstemthereof received in1a=circumferential= groove-in the head 14.` The bearing l isapreferably, thoughnotnecessarily, composedl of`twoor .more segments. andi itis also preferred 'that 'the hearing have.ancinterference fit with the shellr when the parts areV` initially assembled;`

/Sincefit would `beaimpossible-to obtainaproperesealby the use of the bearing alone, a deformable sealing ring"l 50lis;provided.V The sealingringy isofannular configuran tiony andisgenerally semicircular in cross section, as; shown, although -thisparticular crossv sectionneed not bef strictlyadhered to-*since thecrosssection Vmay be of any non-planary form suitable lto accomplish. thedesired resuits;v Two concentric anchor ringsy 51 and 52 Yare utilized in conjunction with the sealing ring 50, the innerl ring 51v being secured as by fasteners 53'to the marginal edgeof'A head 1'4 andthe outer ring S2 being secured; asV by fas-V teners 54passing through flange 14,v directly to the shell 10. The innenand'outer-edgesfoffthesealing ring are welded. throughoutftheir lengths toV theinner andi outer anchor rings-51 and 52, respectively,- soas-toY bridge :and Y providea-seal acrossthe parting -facesbetween the head',` bearing andshell.,

To .allow for relative sliding movement ,between .head 14. and shell 10, the sealing'ring, 50 mustvbe relatively thin-walled and deformable so as Vto -avroidjanyrmaterial transfer of` stress *to the shellthrough the sealing ring..l The Arelative sliding permitted: betweentheA headx "and shell'V ystatic, room temperature conditions.

' course impossibletoY constrain the expansion-,of the various partsso that no extra strain is induced in the mem bers ldueto theY normal discrepancies.inrexpansiom However, the constructionabove described tends to, minimize the stress transfer between shell and heads to such an extent that a shell thickness-ofoulyY 11/2 inches, heretofore 5 unattainable, is permitted with the consequent increase in heat transfer rate between the inner and outer surfaces of the shell. This beneficial result is directly attributable to the provision of the massive ue in combination with the, slip joint, thevmassivc.v ue minimizing thedistortion1 of the annular. head portions. 32V due.. tov

internalcsteam pressure and the slip joint reducing stress, transfer between the parts to at practical minimum.

Although the above described slip, joint construction. utilized in conjunction with a Yankee drier does` ef-v fect. beneficial results even when utilized with arelaf.

tively small fine, the best results are attained by using.

a massivevfiue therewith such as was described above. It isto be understoodthat when the slip joint between one. headv andthe shell is used with such massiveue,

the relativesliding= movement between head and .shell ist` minimized; Also, a better face-to-face contact betweenv the b earing` andi theshell is assured and` consequently lessiv friction is encountered therebetween.`

It will'be understood that` the type'of Yankee-" drier which is under consideration will usually havey adi-.

deformation'which will be normally encountered duringv the forces :acting upon the heads and tendingto deform operation.-

vIf `conventional design is carried forward in a "Yankee' drierl of the diameter and face or length width of theY magnitude contemplated herein the thickness of the shellv must be at least two inches, if not more. In, contrast to this, Yankee driers constructed inaccordance with thisA invention, as hereinabove described, can vbe constructed withshellthicknesses of4 as little as 1% inches which, ofcourse, when compared with the two inch` minimum of the prior art, denotes a 25%. decrease in shell Vthickness and a corresponding increase ofheat trans-V for through the shell. Y

-The principlesV of this invention may be summarized` by stating that the construction of ther drier is such thatthe same will deform them in such a direction and man-v ner/that the portions vof theA heads'which engage the'shell or are secured; thereto will tend to deform in the same direction as the shell when influenced by ther-deforma-Y mum f agsravatedstresses. occurringrparticularlyat the compensa'teslareelv -for'any dscrerancyiinrthe expansion 75 iuncture. Qftlie, xed head and. theshell? 1. A, Yankee drier or the like comprising a thin cylindrical shell, ahead disposed at each end of said Yshell forming closures for the opposite Vends thereof,one of said heads being rigidly eonnectedin its marginal edge portion to said she1l,'an, annular bearing interposed between the outer head and said shell to permit relative slidingibetween such other head and the shell, means for admitting steam under pressure into the drier, and means rigidly interconnecting central portions of said heads, said means being connected to the heads at a diameter approximately 60% to 75% of the diameter of said shell, and sealing means secured across the parting faces between the other head, the bearing and the shell.

2. The structure defined in and by claim 1 wherein said sealing means includes concentric inner and outer rings detachably secured respectively to said other head and the corresponding end of the shell, and an annular sealing ring of non-planar cross section having its inner and outer edges respectively sealed and secured throughout their lengths to said inner andouter annular rings respectively.

3. A Yankee drier or the like comprising a thin cylindrical shell, a head disposed at each end of said shell forming closures for the opposite ends thereof, one of said heads being rigidly connected at its marginal edge portion to said shell, an annular bearing interposed between the other head and said shell to permit relative sliding between such other head and the shell, means for admitting steam under pressure into the drier, me'V ns rigidly interconnecting central portions of said heads, said means being connected to the heads at a diameter approximately 60% to 75 of the diameter of sad shell, sealing means secured across the parting faces between the other head, the bearing and the shell, said sealing means including concentric inner and outer rings detachably secured respectively to said other head and the corresponding end of the shell, and an annular ring of non-planar cross section having its inner and outer edges respectively sealed and secured throughout their lengths to Said inner and outer annular rings respectively, said bearing being of T-shaped cross section with the stem thereof received in a circumferential groove in said other head, and said sealing ring being of semi-circular cross section. l

4. A Yankee drier or the like comprising a thin cylindrical shell, a head disposed at each end of said shell forming closures for the opposite ends thereof, one of said heads being rigidly connected in its marginal edge portion to said shell, an annular bearing interposed between the other head and said shell to permit relative sliding between said such other head and the shell, scaling means secured across the parting faces between the other head, the bearing and the shell, means for admitting steam under pressure into the drier, and means rigidly interconnecting central portions of said heads, the last mentioned means being connected to the heads at a diameter approximately 60% to 75% of the diameter of said shell, the thickness of said shell being in the order of l' inches and the diameter of said'shell being in the order of 12 feet.

5. A Yankee drier or the like providing for maximum heat transfer and for minimizing shell stresses therein, comprising an outer substantially cylindrical shell, head means closing the opposite ends of said shell, a hollow ue concentrically disposed within said shell and rigidly interconnecting said head means, the shell being rigidly secured at one end thereof to one of the head means, an annular bearing interposed between the other head means and the shell permitting relative longitudinal motion therebetween, sealing means secured across the parting faces between the other head, the bearing and the shell, means connected with the head means for rotatably mounting the drier, means for introducing steam under pressure into the annular chamber defined;

between the'tiue andthe shell, means for removing steamV from said annular chamber, the diameter of said lue beingY from 60% to 75% of the diameter of said shell.

6. The structure defined. in and by claim :5 wherein the thickness of Vsaid Vshell is in the order of 1% inches and the diameter of the shell is approximately 12 feet.

7. The structure deinedV in and by claim 6 wherein the thickness of said Hue is from 1.25 to 2.0 times the thickness of said shell, and the thickness of the head means at least in the area thereof radially outwardly from the juncture of the tlue therewith is from 1.5 to 2.5 times the thickness of the shell.

8. A Yankee drier or the like comprising a cylindrical outer shell, a hollow hue disposed concentrically within said shell, a pair of heads closing the opposite ends of K said shell, means rigidly securing one of the heads to the shell, bearing means interposed between the other head and an inner wall portion of said shell permitting relative sliding therebetween, inner and outer anchor rings detachably secured to said other head and the corresponding end of said shell respectively, and' an annular sealing ring of semi-circular cross section having its inner and outer edges sealed and secured to the inner and outer anchor rings respectively.

9. A Yankee drier or the like comprising a cylindrical outer shell, a pairl of heads closing the opposite ends of said shell, means rigidly interconnecting said heads, means rigidly securing one of the heads to the shell, the other head being slidably engaged with the shell, bearing means interposed between the other head and the inner wall portion of the shell to permit the relative sliding therebetween, said bearing being of T-shape cross section with the stem thereof received in a circumferential groove in said other head.

l0. The structure as defined in and by claim 9 wherein sealing means is secured across the parting faces in the other head, the bearing and the shell, said sealing means including concentric inner and outer rings detachably secured respectively to the other head at theother end of the shell and an annular sealing ring of semi-circular cross section having its inner and outer edges respectively sealed and secured throughout their lengths to the inner and outer rings.

1l. A Yankee drier or the like comprising a cylindrical outer shell, a hollow Hue disposed concentrically within the shell, means for introducing steam under pressure into the space defined between the tlue and the shell, and a pair of heads closing. the opposite ends of the shell and rigid with said ue, one of said heads being rigidly secured to the shell, bearing means interposed between said shell and the other head such `that said other head is slidably engaged with the shell, and sealing means secured across the parting faces between said other head and the shell, the tlue diameter being from 60 percent to 75 percent the diameter of said shell and the shell thickness being in the order of 11/2 inches.

12. A Yankee-drier or the like comprising a generally cylindrical outer shell, a head closing each end of the shell, bearing means on the heads for rotatably supporting the drier, and a hollow Hue rigidly interconnecting the heads, one of said heads being rigidly attached to the shell, bearing means interposed between said shell and the other head such that said other head is slidably engaged with the shell, sealing means secured across the parting faces between said other head and the shell, means for circulating heating uid from the interior of said ue to the interior of said shell, the llue diameter being of from 60 to 75 percent of the diameter of said shell to leave only a relatively small annular portion of each head which is disposed between the ue and the shell such that the outer marginal edges of the annular portions are deformable by the pressure and temperastress transfer between the heads and lthe"v shell'. n 15JY Y 'References Cited-in thetlA of this.. patent UNITEDSTATES PATENTS Ritchie June 4*, 1929 lo Henderson et al Aug. 13, 1929 Dukes Feb. 2:7, 1934 EOREIG; PATENTS: Y Y. Germany Y Y....,.Y.. .v r May:V 1, 1911 Denmark Apr; 20,` 1953

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