US3508535A - Grate - Google Patents

Grate Download PDF

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Publication number
US3508535A
US3508535A US732700A US3508535DA US3508535A US 3508535 A US3508535 A US 3508535A US 732700 A US732700 A US 732700A US 3508535D A US3508535D A US 3508535DA US 3508535 A US3508535 A US 3508535A
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United States
Prior art keywords
grate
protuberant
cooling channels
cooling
portions
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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
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US732700A
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English (en)
Inventor
Johannes Josef Martin
Walter Josef Martin
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Individual
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Individual
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23H—GRATES; CLEANING OR RAKING GRATES
    • F23H17/00—Details of grates
    • F23H17/12—Fire-bars
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23H—GRATES; CLEANING OR RAKING GRATES
    • F23H3/00—Grates with hollow bars
    • F23H3/02—Grates with hollow bars internally cooled

Definitions

  • a gate for supporting combustible materials in furnaces includes a plurality of grate bars each of which has a straight main bar portion formed with cooling channels for cooling uid, and protuberant portions projecting from the main bar portion.
  • the protuberant portions are provided with internal compartments communicating with at least some of the cooling channels in the associated main bar portion so as to provide for cooling off the protuberant portions to protect the same against adverse effects of elevated temperatures.
  • the present invention relates to grates, and more specifically to grates of the type used in furnaces and similar installations.
  • the material-supporting grates in furnaces serve to hold theI material to be combusted in predetermined position. They generally consist of a plurality of grate bars and these latter are usually cooled by providing them with cooling channels through which cooling fluid is circulated. This is done to protect the grate bars as much as possible against the adverse influences of the elevated temperatures to which they are subjected during combustion of the combustible material. If this is not done, the life of these grate bars is significantly reduced.
  • adjacent grate bars of grates of the type here in question are arranged to perform relative movements, for instance reciprocatory movements relative to one another, so as to stir the bed of combusting material and/ or break up this bed or individual components thereof, such as lumps of slag and the like.
  • the grate bars are usually provided with protuberant portions which project to one side of the respective grate bars, usually in opposite direction above the general plane of the grate. This is shown for example in German Patents 959,212 and 969,643.
  • protuberant projections have been found highly advantageous because they not only serve to stir up the bed of combusting material, loosening the individual components of the bed and thus providing for increase circulation of necessary combustion air therethrough, but also because they serve to break up such individual components as lumps of slag, as pointed out above, and thus serve to accelerate combustion of the thereby obtained smaller pieces.
  • protuberant projections which are not protected against the adverse influences of elevated temperatures as are the main portions of the respective grate bars, are destroyed much more quickly than the latter under the very intense heat developing in installations of the type here in question.
  • protuberant projections it is pointed out that it is an important feature for the protuberant projections to have relatively sharp edges which factor assists in the crushing of materials to smaller pieces, and these sharp edges are destroyed particularly under these circumstances just outlined. Added to this is the fact that significant local overheating in the protuberant projections may result in the development of internal stresses and the formation of cracks.
  • a more particular object of the invention is to provide an improved grate of the type under discussion which eliminates the above-mentioned disadvantages but it does so in a simple and inexpensive but yet highly advantageous manner.
  • a concomitant object of the invention is to provide a grate of the type in question which does not require the provision of additional cooling means for obtaining the purposes outlined above.
  • Yet a .further object of the invention is to provide such ⁇ a grate which may be utilized with equal advantage in many types of installations where materials are to be combusted, for example in various types of industrial furnaces including batch-type furnaces, continuous-type furnaces and others.
  • a grate of the type here under discussion which comprises a plurality of grate bars serving a main bar portion formed with cooling channels for the passage of the cooling fluid therethrough, and protuberant portions projecting from the main bar portions.
  • the protuberant portions are provided with respective internal compartments which communicate with at least some of the cooling channels of the associated main bar portion so as to provide access of the cooling fluid from such cooling channels to the internal compartments.
  • protuberant projections are subjected to effective direct cooling so that the material of which they consist is subjected to internal cooling, resulting in an increase of its ability to withstand mechanical stresses and in a consequent increase of its lifetime.
  • FIG. 1 is a somewhat diagrammatic side-elevational fragmentary view of two grate bars embodying the invention
  • FIG. 2 is a section, on an enlarged scale, taken on the line II-II of FIG. 1;
  • FIG. 3 is a vertical fragmentary section through a grate bar incorporating a further embodiment of the invention.
  • FIG. 1 we have illustrated the end portions of two grate bars 1 of the type here under discussion. It will be appreciated that such grate bars are elongated, that is in FIG. 1 in the direction towards the left-hand side of the drawing, and that each grate comprises a plurality these grate bars which in the embodiment of FIG. 1 are arranged in two superimposed layers, each of which is diagrammatically represented by the respectively lower and the respectively upper grate bar 1 in FIG. 1. This, however, is of no direct importance for the present invention except that it should be remembered that in an embodiment of this type the grate bars of the upper and lower layers may be arranged reciprocally with reference to one another.
  • the grate bars each comprise a main bar portion 1 and protuberant portions 2. Although only one of these portions 2 is shown in FIG. 1 for each of the grate bars it will be understood that there may be two associated with each grate bar, namely one located at each opposite end of the grate bar, or that there may be more than two.
  • the protuberant portions 2 are located in the region of the illustrated ends of the grate bars, rearwardly of the respective end faces 5.
  • FIG. 2 which is a section taken on the line II-II of FIG. 1 but on an enlarged scale, shows that the grate bars are provided with a plurality of cooling channels 3 extending in longitudinal direction.
  • These cooling channels 3 in the illustrated embodiment are bounded by the respective outermost wall portions 1a of the grate bar, and the space between the wall portions 1a is further subdivided by wall portions 1b so as to provide a plurality of the longitudinally extending cooling channels 3. It will be notified that these extend from what in the drawing will be seen to be the lower surface of each grate bar in the direction towards the upper surface, from which the protuberant portions 2 extend, but that they terminate short of this upper surface. This is clearly shown in FIG. 2. While in FIGS.
  • the cooling channels 3 are seen to be open at the lower surface of the grate bars, it will be appreciated that they may also be closed by a suitable closure means, such as an elongated strip or plateshaped member which is illustrated in FIG. 3 and which will be further discussed in the discussion of the embodiment illustrated in that figure.
  • a suitable closure means such as an elongated strip or plateshaped member which is illustrated in FIG. 3 and which will be further discussed in the discussion of the embodiment illustrated in that figure.
  • the protuberant projections 2 of which only one is visible in FIG. 2, are provided with internal compartments 4 which are illustrated in broken lines in FIG. 2 and which communicate with respective ones of the elongated cooling channels 3.
  • cooling fiuid which circulates through the cooling channels 3 will also enter into these internal compartments 4 and will thereby cool the protuberant projections 2 with the highly advantageous results outlined above.
  • cooling channels 3 communicate with the one or several internal compartments in each of the respective protuberant projections 2. In the illustrated embodiment, however, only some of the cooling channels 3 are in such communication. The others, in FIG. 2 the respectively laterally outermost ones, are not so in communication. However, in the region of the grate bar beneath the respective protuberant projection 2 the cooling channels which are not in communication with the internal compartment or compartments in the protuberant projections 2, extend at least closer to the upper surface of the grate bars 1. This is indicated in broken lines in FIG. 2 where it will be seen that in the region below the protuberant projections 2 the laterally outermost ones of the cooling channels 3 are upwardly extended so as to provide hollow upper extensions 3a. The reason for showing these extensions 3a in dash lines in FIG. 2 will be appreciated when the section line II--II in FIG. 1 is considered.
  • FIG. 3 it will be seen that it is illustrated herein a vertical longitudinal section through an end portion of a grate bar of the type shown in FIG. l.
  • the main bar portion is identified with this embodiment with reference numeral 1', the protuberant projection with reference numeral 2 and its end face with reference numeral 5.
  • the partition walls 1a and 1b respectively correspond to those identified with reference numerals 1a and 1b in FIG. 2.
  • Reference numeral 3 in FIG. 3 identies one of the cooling channels 3. Unlike the embodiment in FIG. 2, the embodiment illustrated in FIG. 3 does not have downwardly open cooling channels 3.
  • an elongated closure means in form of a strip, plate or similar element is identified with reference numeral 6 and closes the downwardly open cooling channels 3 in the manner illustrated in FIG. 3.
  • the internal compartment or compartments in the protuberant projection 2 are identified with reference numeral 4 in FIG. 3.
  • the compartment 4' is elongated in longitudinal direction of the protuberant projection 2 so as to comprise a portion 4 extending towards but short of the face 5 of the grate bar. This serves to provide still more intensive cooling, particularly also in the region of the face 5', and thus protects the grate bars still better.
  • FIG. 3 A further difference of the embodiment in FIG. 3 over that shown in FIGS. 1 and 2 is the fact that the cover or closure means 6 is provided Iwith guide or deliecting means which serves to'guide or deflect the stream of coolant fluid into the compartment 4', 4".
  • this means is an upwardly projecting section 7 of the cover means 6 which projects upwardly into the compartment 4', 4" and thus serves to deflect the stream of coolant uid, whose path is shown in dashed line and identified with reference designation y, upwardly into the compartment 4', 4 in the manner shown in FIG. 3.
  • a plurality of elongated grate bars having a main bar portion formed with a plurality of longitudinally extending transversely spaced cooling channels for passage of a cooling fluid therethrough, and protuberant portions projecting from said main bar portions; and internal compartments provided in the respective protuberant portions and communicating with at least some of said cooling channels of the associated main bar portions for enabling access of the cooling fluid from said plurality of cooling channels to said internal compartments to thereby effect intensive cooling of said protuberant portions and protection of the latter against adverse effects of elevated temperatures.
  • a grate as defined in claim 1 wherein said grate bars have respective opposite ends each having an end face, said protuberant portions being provided in the region of said ends inwardly of the respective end faces, and wherein said internal compartments extend in said protuberant portions in longitudinal direction of said grate bars and towards the respectively associated end face.
  • each of said grate bars having a first surface from which the respective protuberant portions project and an opposite second surface, and each of said grate bars being provided with said plurality of said cooling channels extending inwardly from said opposite second surface to within a predetermined distance of said first surface beneath the respective protuberant portions; and wherein some of said cooling channels communicate with said internal compartments and the remaining ones of said cooling channels compose sections extending to within a smaller distance of said first surface than said predetermined distance in the region beneath the respective protuberant portions.
  • said grate bars each having a first surface from 'which said protuberant projections extend and an opposite second surface, said cooling channels being provided in said second surface and extending longitudinally of the respective grate bar as well as inwardly of said second surface toward said first surface, and wherein said cooling channels are open at said second surface.
  • said grate bars each having a first surface from which said protuberant projections extend and an opposite second surface, said cooling channels being provided in said second surface and extending longitudinally of the respective grate bar as well as inwardly of said second surface toward said first surface, said cooling channels being open at said second surface; and further comprising cover means clos ing said cooling channels at said second surface.
  • cooling channels being open at said opposite second surface; and further comprising cover means closing said cooling chan nels at said second surface and including guide portions operative for defiecting cooling fiuid into said internal compartments from the respective cooling channels communicating with the same.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Incineration Of Waste (AREA)
  • Furnace Details (AREA)
  • Heat Treatments In General, Especially Conveying And Cooling (AREA)
US732700A 1967-06-02 1968-05-28 Grate Expired - Lifetime US3508535A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE1551872 1967-06-02

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US3508535A true US3508535A (en) 1970-04-28

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ID=5676851

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US732700A Expired - Lifetime US3508535A (en) 1967-06-02 1968-05-28 Grate

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US (1) US3508535A (de)
CH (1) CH463678A (de)
FR (1) FR1567605A (de)
GB (1) GB1229836A (de)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4103627A (en) * 1975-09-04 1978-08-01 Morse Boulger, Inc. Stoker and grate therefore
US4239029A (en) * 1978-02-24 1980-12-16 Josef Martin Feuerungsbau Gmbh Grate for industrial furnaces
USRE30725E (en) * 1980-02-26 1981-09-01 Fireplace grate
US4671190A (en) * 1984-11-30 1987-06-09 Electricite De France (Service National) Fire grate
US4672947A (en) * 1982-08-17 1987-06-16 Martin Johannes J E Grate bar for use in industrial furnaces
US4719900A (en) * 1985-06-13 1988-01-19 Martin Walter J Grate for use in industrial furnaces
US5245983A (en) * 1991-02-18 1993-09-21 Noell K+K Abfalltechnik Gmbh Grate bar and grate for combustion plants
EP2034243A1 (de) * 2007-09-10 2009-03-11 Babcock & Wilcox Vølund A/S Gestufter Roststab für einen Verbrennungsrost

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2599817A1 (fr) * 1986-06-04 1987-12-11 Mediterranee Const Navales Ind Barreau de grille de combustion ou d'incineration
FR2616885B1 (fr) * 1987-06-17 1989-09-22 Mediterranee Const Navales Ind Barreau de grille de combustion ou d'incineration, notamment de grille a mouvement de recul
FR2694376B1 (fr) * 1992-07-31 1994-09-30 A3C Metal Barreau pour grille d'incinération d'ordures ménagères.
DE10201057A1 (de) * 2002-01-14 2003-07-24 Polysius Ag Austragsboden

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1646700A (en) * 1925-04-23 1927-10-25 Alexander Gale Furnace-grate-bar construction
US1664903A (en) * 1928-04-03 Automatic stoker
US2197428A (en) * 1937-06-11 1940-04-16 Clarence F Erb Automatic stoker
US2745364A (en) * 1948-10-01 1956-05-15 Martin Johannes Josef Combustion air supply through grates and grate construction

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1664903A (en) * 1928-04-03 Automatic stoker
US1646700A (en) * 1925-04-23 1927-10-25 Alexander Gale Furnace-grate-bar construction
US2197428A (en) * 1937-06-11 1940-04-16 Clarence F Erb Automatic stoker
US2745364A (en) * 1948-10-01 1956-05-15 Martin Johannes Josef Combustion air supply through grates and grate construction

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4103627A (en) * 1975-09-04 1978-08-01 Morse Boulger, Inc. Stoker and grate therefore
US4239029A (en) * 1978-02-24 1980-12-16 Josef Martin Feuerungsbau Gmbh Grate for industrial furnaces
USRE30725E (en) * 1980-02-26 1981-09-01 Fireplace grate
US4672947A (en) * 1982-08-17 1987-06-16 Martin Johannes J E Grate bar for use in industrial furnaces
US4671190A (en) * 1984-11-30 1987-06-09 Electricite De France (Service National) Fire grate
US4719900A (en) * 1985-06-13 1988-01-19 Martin Walter J Grate for use in industrial furnaces
US5245983A (en) * 1991-02-18 1993-09-21 Noell K+K Abfalltechnik Gmbh Grate bar and grate for combustion plants
EP2034243A1 (de) * 2007-09-10 2009-03-11 Babcock & Wilcox Vølund A/S Gestufter Roststab für einen Verbrennungsrost
WO2009034509A1 (en) * 2007-09-10 2009-03-19 Babcock & Wilcox Vølund A/S Stepped combustion grate

Also Published As

Publication number Publication date
FR1567605A (de) 1969-04-08
CH463678A (de) 1968-10-15
GB1229836A (de) 1971-04-28

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