US3861360A - Steam generator buckstay leveler systems - Google Patents

Steam generator buckstay leveler systems Download PDF

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Publication number
US3861360A
US3861360A US459761A US45976174A US3861360A US 3861360 A US3861360 A US 3861360A US 459761 A US459761 A US 459761A US 45976174 A US45976174 A US 45976174A US 3861360 A US3861360 A US 3861360A
Authority
US
United States
Prior art keywords
buckstay
furnace
pipe
buckstays
elevation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US459761A
Other languages
English (en)
Inventor
Jr John Mohr Shank
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Combustion Engineering Inc
Original Assignee
Combustion Engineering Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Combustion Engineering Inc filed Critical Combustion Engineering Inc
Priority to US459761A priority Critical patent/US3861360A/en
Priority to IN86/CAL/1975A priority patent/IN141073B/en
Application granted granted Critical
Publication of US3861360A publication Critical patent/US3861360A/en
Priority to CA219,353A priority patent/CA1015343A/en
Priority to DE19752514858 priority patent/DE2514858B2/de
Priority to ZA00752181A priority patent/ZA752181B/xx
Priority to JP50041932A priority patent/JPS50136501A/ja
Priority to AU79953/75A priority patent/AU485698B2/en
Priority to FI751065A priority patent/FI56585C/fi
Priority to AR258313A priority patent/AR203065A1/es
Priority to NL7504237.A priority patent/NL161567C/nl
Priority to IT22164/75A priority patent/IT1034980B/it
Priority to FR7511075A priority patent/FR2267519B1/fr
Priority to ES436451A priority patent/ES436451A1/es
Priority to SE7504095A priority patent/SE405164B/sv
Priority to GB1461875A priority patent/GB1465246A/en
Priority to JP1977167092U priority patent/JPS5729125Y2/ja
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/10—Water tubes; Accessories therefor
    • F22B37/20—Supporting arrangements, e.g. for securing water-tube sets
    • F22B37/208—Backstay arrangements

Definitions

  • ABSTRACT Apparatus for maintaining the buckstays of a steam generator level.
  • Upper and lower buckstays are mounted in a cantilever fashion from vertically expanding steam generator furnace walls.
  • a first rigid member extends vertically upward from the lower buckstay and a second rigid hollow member extends vertically downward from the upper buckstay and telescopically engages the first member.
  • the bending moment of each buckstay around its support is resisted by a horizontal force acting between the two vertical members through their telescopic engagement.
  • This invention relates to steam generators and in particular to an apparatus for maintaining the buckstays thereof level without excessive bending forces on the buckstay supports.
  • Large steam generators generally have furnaces which are lined with steam generating tubes and which are supported from the top of the unit. As the unit approaches operating temperature, the furnace structure expands vertically downward as well as horizontally. Some units operate with pressure in the furnace at all times, while others operate with negative furnace pressure. In either case, provision must be made for temporary high pressure excursions within the furnace due to minor furnace explosions or pressure increases due to the lighting of an additional burner.
  • buckstays are generally used to provide the necessary additional support. These buckstays are stiff structural members located outside the furnace structure and supported from it, thus limiting furnace wall distortion. Since furnace pressure acts on all furnace walls, the buckstays on opposite walls are connected through buckstay ties so thatthe reactions of one buckstay are resisted by the reactions of the opposing buckstay.
  • the vertical expansion of a large steam generator is in the order of 12 inches throughout its height. I-Iorizontal expansion of the furnace walls also occurs.
  • the buckstays being positioned outside the furnace, are at lower temperatures and do not expand to the same extent as the furnace walls. Therefore it has become accepted practice to support these buckstays from the furnace wall tubes at various elevations so that each buckstay moves vertically with the furnace wall tubes an amount depending on the vertical expansion of the steam generator at the particular buckstay elevation.
  • the buckstay is fixed to the furnace wall at one location and permitted to slide with respect to the furnace wall at other supports.
  • the tie between opposing buckstays is arranged in close proximity with the furnace so that the tie rod structure approaches the furnace wall temperature. As a result horizontal movement of opposing buckstays approximates the furnace expansion.
  • buckstays are supported from the furnace wall in a cantilever fashion with the buckstay weight causing a bending moment around the support. Additional forces may be imposed on the buckstays, as for example where they are used for supporting pipes or other members. Resisting the bending moment at the support would lead to high forces on the support members. Such forces in the support members would interfere with the sliding action which is required due to the relative expansion between the furnace wall structure and the buckstay, and would also produce a very high localized bending moment, and therefore high stresses in the furnace wall tubes.
  • a vertical member extends downwardly from the upper buckstay to a lower buckstay leaving a few inches clearance from the lower buckstay.
  • a clip on the lower buckstay interacts with the vertical member from above so as to resist the bending moment of the upper buckstay and resolve it into a force normal to the furnace wall. This is repeated throughout the height of the unit with three of four vertical members being positioned between each pair of buckstays.
  • the lowest buckstay has vertical members extending upwardly as well as downwardly from the buckstay above. In this fashion, the bending moment of the lower buckstay is resolved into a normal force at the buckstay elevation above and vice versa.
  • the two members overlap and en gage one another in a manner whereby horizontal forces may be transmitted between the members at a location where the bending moment for each buckstay supplies the proper resisting force for the other buckstay.
  • This arrangement is repeated throughout the elevation of the steam generator with the buckstays operating in pairs, thereby limiting the number of vertical members needed to one-half of those required in the other described arrangements.
  • the means for transmitting the horizontal forces between the overlapping vertically extending members have included mating flat surfaces, and a bolted connection between the two vertically extending members. While ideally an arrangement employing abutting flat surfaces between the two beams would result in a sliding surface contact between the two, in reality a horizontal line contact most probably exists in either the upper end of the lower beam or the lower end of the upper beam. Such a condition, taken with the fact that the two buckstays involved may be moving at different rates or at different magnitudes due to thermal expansion differentials, results in a rather precarious contact between the two beams. As a result, a very real possibility exists that the beams could slip out of engagement with one another and become ineffective.
  • the present invention overcomes the disadvantages of the prior means for transmitting the horizontal forces in a buckstay leveler system of the type wherein bending moments of an upper and lower buckstay are used to counteract one another through vertically extending rigid members.
  • the upper and lower vertically extending rigid members are constructed and arranged to engage one another in a telescoping fashion. Such an arrangement results in a stable, simple engagement between the opposing members which has none of the disadvantages of the prior art arrangement.
  • FIG. 1 is a plan view through a steam generator furnace showing the general arrangement of buckstays and buckstay levelers.
  • FIG. 2 is a side elevation of a buckstay leveler according to the present invention.
  • FIG. 3 is a sectional view taken along the Line 33 of FIG. 2.
  • FIG. 4 is a side elevation of a second embodiment of a buckstay leveler according to the present invention.
  • FIG. 5 is a sectional view taken along the Line 5-5 of FIG. 4.
  • FIG. 1 being a sectional plan view of a steam generator shows furnace 2 which has its walls lined by a plurality of vertical steam generating tubes 3. These tubes extend throughout the height of the steam generator and expand longitudinally as the unit comes up to operating temperature. Since the parallel furnace wall tubes are interconnected laterally by welding adjacent tubes together, the furnace will also expand horizontally.
  • opposing buckstays 4 and 5 are positioned on opposing walls while opposing buckstays 6 and 7 are positioned on the adjacent pair of opposing walls. These buckstays are supplied at a number of elevations and are supported in a manner illustrated in FIGS. 2 and 4.
  • Buckstay ties 8 are connected to each end of each buckstay so that the force tending to move buckstay 5 to the left is opposed by the force tending to move buckstay 4 to the right. These buckstay ties 8 are formed in several parts with one part 9 maintained in close relationship with the furnace wall so that it approaches the furnace tube temperature through their co-extensive portion, and the buckstay tie portion 9'expands to the same extent that the furnace expands horizontally. This permits the buckstays to move outwardly from each other as the furnace expands whereby the buckstays maintain the same spaced relationship with their adjacent furnace wall tubes.
  • lower buckstay 4 is supported from the furnace wall tubes 3 by stirrup l7 and bolt 18.
  • a fixed connection is provided between the stirrups and buckstays, near the'centerline of the furnace while at other locations a slotted hole is provided so that furnace may expand horizontally with relation to the buckstay.
  • the weight of the buckstay. 4 produces a clockwise bending moment around the supporting bolt.
  • an upper buckstay 22 is similarly supported from furnace tubes 3 through a second stirrup 23 and bolt 24.
  • This buckstay 22 similarly has a clockwise bending moment around its support caused by its own weight.
  • a rigid circular pipe section 25 is welded to the lower buckstay 4 and extends vertically upward therefrom.
  • a second rigid circular pipe section 27 is welded to the upper buckstay 22. This second pipe 27 has a larger inner diameter than the outer diameter of pipe 25 and extends vertically downward and telescopically receives the upper end of the pipe 25.
  • the clockwise bending moment of the buckstay 4 accordingly causes the vertically extending member 25 to tend to rotate in a clockwise direction, that is to the right-hand side.
  • the clockwise bending moment of the buckstay 22 causes the vertically extending member 27 to tend to rotate in a clockwise direction. In this case to the left-hand side.
  • the beams 25, 27 to move in opposite directions they are caused to contact one another in the region of telescopic engagement and the oppositely directed horizontal forces of the two beams will tend to cancel one another, thus resisting the bending moments caused by the weight of the two buckstay members 22, 4.
  • the two buckstay members 22, 4 may be expanding vertically at a differential rate, this differential rate of movement is accommodated by the sliding engagement of the telescopically engaged upper and lower vertically extending pipe members25, 27.
  • the point of contact between the two members, as indicated at elevation 28, is selected so that the horizontal forces imposed are sufficient to counteract the bending moments of each buckstay.
  • the distance between the center of the web portion of the upper buckstay 22 and the intermediate elevation 28 designated by L1 is equal to the vertical distance between the intermediate elevation 28 and the center of the web portion of the lower buckstay 4 as designated by L2.
  • the vertical distances L1 and L2 will be inverse proportion to the bending moment of each buckstay around its respective support. If additional loads are imposed on the buckstays, such as piping support, these loads will be considered in determining L1 and L2 so as to arrive at the proper intermediate elevation 28, so that the horizontal forces may be reacted against one another in order to oppose the bending moments of each of the buckstays.
  • buckstays 5, 6 and 7 are coupled with corresponding buckstays at an upper elevation and use a construction similar to that illustrated in FIGS. 2 and 3.
  • the remaining buckstays on the steam generator at various elevations are treated in pairs in the same manner as buckstays 4 and 22.
  • the horizontal force to the left imposed on vertically extending pipe 25 results in a force towards the furnace wall on the lower buckstay 4.
  • the same force acting in the other direction from vertically extending pipe 27 imposes a force away from the furnace wall on the upper buckstay 22.
  • the identical arrangement as shown in FIG.
  • FIGS. 4 and 5 illustrate an alternate arrangement wherein all of the structural features of the buckstay leveler system are the same as those described in FIGS. 2 and 3, with the exception that the vertically extending pipe 29 extending downwardly from the upper buckstay 22 is fabricated from a square channel. This square channel 29 similarly, telescopically and slidably engages the pipe 25 extending upwardly from the lower buckstay 4. The relationship between the moments and corresponding forces are the same as in the first embodiment.
  • Apparatus for maintaining level the buckstays of a steam generator having a vertically'expanding furnace structure said steam generator having a first buckstay at a lower elevation, a first support supporting said first buckstay from the furnace structure in a cantilever fashion; said steam generator also having a second buckstay at an upper elevation, and a second support supporting said second buckstay from the furnace structure in a cantilever fashion comprising: a first member rigidly fastened to said first buckstay and extending upwardly; an a second member rigidly fastened to said buckstay and extending downwardly and slidably and telescopingly engaging said first member, said telescopic engagement of said first and second members permitting transmission of horizontal force said first and second members at an intermediate elevation between said first and second buckstay elevation; said intermediate elevation being a vertical distance from said first and second supports in inverse proportion to the bending moment of said first and second buckstays around their respective supports.
  • first member comprises a first pipe of circular cross section welded to said first buckstay and extending vertically upward and said second member comprises a second circular pipe having an inner diameter greater than the outer diameter of said first pipe and extending vertically downward in telescopic relation with said first pipe.
  • first member comprises a pipe of circular cross section welded to said first buckstay and extending vertically upward and said second member comprises a square tube having an inner flat-to-fiat dimension greater than the outer diameter of said pipe and extending vertically downward in telescopic relation to said pipe.
  • first and second buckstays, said first and second supports, and said first and second members comprise a buckstay structure; having also an identical buckstay structure on the opposite side of the furnace structure; buckstay ties connecting each end of the upper buckstay on one side of the furnace to the corresponding end of the upper buckstay on the other side of the furnace; and buckstay ties connecting each end of the lower buckstay on one side of the furnace to the corresponding ends of the buckstay on the opposite of the furnace.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Tunnel Furnaces (AREA)
  • Clamps And Clips (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Heat Treatment Of Articles (AREA)
  • Treatment Of Fiber Materials (AREA)
  • Supports For Pipes And Cables (AREA)
US459761A 1974-04-10 1974-04-10 Steam generator buckstay leveler systems Expired - Lifetime US3861360A (en)

Priority Applications (16)

Application Number Priority Date Filing Date Title
US459761A US3861360A (en) 1974-04-10 1974-04-10 Steam generator buckstay leveler systems
IN86/CAL/1975A IN141073B (nl) 1974-04-10 1975-01-15
CA219,353A CA1015343A (en) 1974-04-10 1975-02-04 Steam generator buckstay leveler systems
DE19752514858 DE2514858B2 (de) 1974-04-10 1975-04-04 Bandage fuer dampferzeuger-brennkammern
ZA00752181A ZA752181B (en) 1974-04-10 1975-04-07 Steam generator buckstay leveler systems
JP50041932A JPS50136501A (nl) 1974-04-10 1975-04-08
AU79953/75A AU485698B2 (en) 1974-04-10 1975-04-08 Steam generator buckstay leveler systems
GB1461875A GB1465246A (en) 1974-04-10 1975-04-09 Steam generator buckstay leveler systems
FI751065A FI56585C (fi) 1974-04-10 1975-04-09 Anordning foer laegeshaollning av foerband hos aonggeneratorer
AR258313A AR203065A1 (es) 1974-04-10 1975-04-09 Estructura para mantener nivelados les atesadores de un generador de vapor
NL7504237.A NL161567C (nl) 1974-04-10 1975-04-09 Constructie voor het in een vlak houden van steunbalken van een stoomketel met een verticaal expanderende vuur- haard.
IT22164/75A IT1034980B (it) 1974-04-10 1975-04-09 Apparecchiatura per mantenere a livello e travi di rinforzo di un generatore di vapore
FR7511075A FR2267519B1 (nl) 1974-04-10 1975-04-09
ES436451A ES436451A1 (es) 1974-04-10 1975-04-09 Aparato nivelador de armaduras de generadores de vapor.
SE7504095A SE405164B (sv) 1974-04-10 1975-04-09 Anordning for bibehallande av nivan for forband pa en anggenerator
JP1977167092U JPS5729125Y2 (nl) 1974-04-10 1977-12-14

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US459761A US3861360A (en) 1974-04-10 1974-04-10 Steam generator buckstay leveler systems

Publications (1)

Publication Number Publication Date
US3861360A true US3861360A (en) 1975-01-21

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ID=23826046

Family Applications (1)

Application Number Title Priority Date Filing Date
US459761A Expired - Lifetime US3861360A (en) 1974-04-10 1974-04-10 Steam generator buckstay leveler systems

Country Status (14)

Country Link
US (1) US3861360A (nl)
JP (2) JPS50136501A (nl)
AR (1) AR203065A1 (nl)
CA (1) CA1015343A (nl)
DE (1) DE2514858B2 (nl)
ES (1) ES436451A1 (nl)
FI (1) FI56585C (nl)
FR (1) FR2267519B1 (nl)
GB (1) GB1465246A (nl)
IN (1) IN141073B (nl)
IT (1) IT1034980B (nl)
NL (1) NL161567C (nl)
SE (1) SE405164B (nl)
ZA (1) ZA752181B (nl)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4240234A (en) * 1978-12-20 1980-12-23 Foster Wheeler Energy Corporation Adjustable buckstay system for vapor generators or the like
US4384550A (en) * 1980-12-19 1983-05-24 Rockwell International Corporation Thermal receiver
WO1991019940A1 (en) * 1990-06-15 1991-12-26 Abb Carbon Ab Frame for bed vessel
US5299535A (en) * 1992-12-29 1994-04-05 Combustion Engineering, Inc. Furnace buckstay stirrup
WO1994015145A1 (en) * 1992-12-29 1994-07-07 Combustion Engineering, Inc. Vertical buckstay/leveler attachment to a horizontal buckstay
US5865149A (en) * 1996-12-23 1999-02-02 Combustion Engineering, Inc. Buckstay corner assembly with buckstay extension plates for a boiler
WO2010078705A1 (zh) * 2009-01-12 2010-07-15 上海锅炉厂有限公司 一种刚性梁平衡杆
KR20160116929A (ko) * 2015-03-31 2016-10-10 두산중공업 주식회사 보일러 벅스테이 연결장치
CN106195991A (zh) * 2016-08-26 2016-12-07 哈尔滨哈锅锅炉容器工程有限责任公司 一种用于锅炉的桁架刚性梁装置
US11209158B2 (en) * 2017-10-16 2021-12-28 Sumitomo SHI FW Energia Oy Boiler construction having a boiler pressure body support system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0443682Y2 (nl) * 1985-02-21 1992-10-15

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3078830A (en) * 1958-03-17 1963-02-26 Babcock & Wilcox Ltd Tubulous boiler walls
US3203376A (en) * 1963-12-30 1965-08-31 Combustion Eng Buckstay arrangement for furnace walls
US3277870A (en) * 1965-12-30 1966-10-11 Foster Wheeler Corp Buckstay arrangement for vapor generators and the like
US3461847A (en) * 1967-12-22 1969-08-19 Combustion Eng Automatic furnace temperature control

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3078830A (en) * 1958-03-17 1963-02-26 Babcock & Wilcox Ltd Tubulous boiler walls
US3203376A (en) * 1963-12-30 1965-08-31 Combustion Eng Buckstay arrangement for furnace walls
US3277870A (en) * 1965-12-30 1966-10-11 Foster Wheeler Corp Buckstay arrangement for vapor generators and the like
US3461847A (en) * 1967-12-22 1969-08-19 Combustion Eng Automatic furnace temperature control

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4240234A (en) * 1978-12-20 1980-12-23 Foster Wheeler Energy Corporation Adjustable buckstay system for vapor generators or the like
US4384550A (en) * 1980-12-19 1983-05-24 Rockwell International Corporation Thermal receiver
WO1991019940A1 (en) * 1990-06-15 1991-12-26 Abb Carbon Ab Frame for bed vessel
US5329892A (en) * 1990-06-15 1994-07-19 Abb Carbon Ab Frame for bed vessel
US5299535A (en) * 1992-12-29 1994-04-05 Combustion Engineering, Inc. Furnace buckstay stirrup
WO1994015145A1 (en) * 1992-12-29 1994-07-07 Combustion Engineering, Inc. Vertical buckstay/leveler attachment to a horizontal buckstay
US5865149A (en) * 1996-12-23 1999-02-02 Combustion Engineering, Inc. Buckstay corner assembly with buckstay extension plates for a boiler
WO2010078705A1 (zh) * 2009-01-12 2010-07-15 上海锅炉厂有限公司 一种刚性梁平衡杆
KR20160116929A (ko) * 2015-03-31 2016-10-10 두산중공업 주식회사 보일러 벅스테이 연결장치
CN106195991A (zh) * 2016-08-26 2016-12-07 哈尔滨哈锅锅炉容器工程有限责任公司 一种用于锅炉的桁架刚性梁装置
US11209158B2 (en) * 2017-10-16 2021-12-28 Sumitomo SHI FW Energia Oy Boiler construction having a boiler pressure body support system

Also Published As

Publication number Publication date
ES436451A1 (es) 1977-01-01
AU7995375A (en) 1976-10-14
FR2267519B1 (nl) 1980-12-05
FI56585B (fi) 1979-10-31
AR203065A1 (es) 1975-08-08
ZA752181B (en) 1976-03-31
JPS5729125Y2 (nl) 1982-06-25
IT1034980B (it) 1979-10-10
IN141073B (nl) 1977-01-15
FI56585C (fi) 1980-02-11
SE7504095L (sv) 1975-10-13
FI751065A (nl) 1975-10-11
DE2514858A1 (de) 1975-10-23
JPS5398201U (nl) 1978-08-09
NL161567C (nl) 1980-02-15
JPS50136501A (nl) 1975-10-29
CA1015343A (en) 1977-08-09
GB1465246A (en) 1977-02-23
NL161567B (nl) 1979-09-17
SE405164B (sv) 1978-11-20
NL7504237A (nl) 1975-10-14
DE2514858B2 (de) 1976-07-22
FR2267519A1 (nl) 1975-11-07

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