US1899537A - Furnace grate - Google Patents

Description

FURNACE GRATE 'Filed March 8, 1930 ATTOR NEY Patented Feb.V 28, 1933 entre. srarss earner este JAMES S. THOMPSON, OF N EW ROCHELLE, NEW YORK, ASSXGNOR. TO 4lEIIEtilBAR CORPORATION, OF CLEVELAND, OHIO, A COREORATON F DELAKVARE rURNAon anatray Application sitek Maren a,

This invention relates to grates of the type used in locomotives, marineA boiler furnaces, and for other heavy duty purposes. particularly, the present invention is conce1-ned with a grate bar which offers numerous advantages over those now in ordinary use by virtue of various features of novelty in construction. rllhe new grate bar .will be described in a form suitable for use in a locomotive re box but it is to be understoodL that the utility of the invention is not confined to that particular use which is described merely for purposes of illustration.

As the demands on motive power have increased in the last few years, larger fire bones have been installed and as a consequence the weight of the grate bars and grate frames has substantially increased. rlhe increase in size and weight of locomotives is limited by the strength ofbridoes, road-bed, etc. and since many new appliances such as feed water heaters, superheaters, and the like have been installed on modern locomotives, efforts have been made to reduce the weight of the grate equipment` as much as possible. As a consequence, the cast iron grate bars heretofore in common use have to some extent been replaced by steel bars, but these bars, while lighter in Weight, have the disadvantage that they are likely to sag and bend out of shape in service. As a consequence, vthe advantage of light weight is largely overcome by the cost of replacement.

This invention is accordingly directed to the provision of a grate bar which affords a more eflicient means of burning fuel 'than the bars now commonly employed and which is substantially lighter per unit of grate area than standard bars of the same material. The new bar may be made of castiron or steel as may be desired, each metal offering the customary advantages thereof and the bar.

itself being not only lighter in weight but of longer life due to the provision of means for ventilating it and thus preventing its reaching a temperature which in the case of'a steel bar would result in distortion. .v

The new bar comprises a longitudinal supporting member on which a plurality of fuelsupporting units are mounted. These units More ieee. sans; no. 434,254. Y

preferred. The carrier bar is made of vlight weight by being' constructed with a longitu- 55 dinal channel'in itsfunder surface and it pref- V erably has anl inverted U-shape. Through -V the top of the carrier member are air ports which communicate withthe air channel so n that air can flow upwardly from the ashpan A into the channel and thence through the i ports to the fuel. At the ends, the carrier bar is provided with the usual trunnions but these trunnions are made hollow and they are in communicationk with the Vchannel so that air can flow throu'gh'th'e trunnions to keep them cool. y The top walls ofthe trunnions are also provided with air ports for` the flow of 'air through the trunnions to points inVv the fuel bed which lie above the trunnions. 7o l/Vith the ordinary bar, no air reaches the Y fuel which lies above the trunnions supported inv sockets in grate frames and this fuel .is consequently burned inefliciently. "With the present bar, the trunnions themselves serve as ,75, a means for supplying air to the fuel and the fuel over the trunnions is burned with as efl'icient combustion as if it were supported on the grat-e bar proper.

rlhe fuel-supporting units may take the form of plates provided with lugs projecting from opposite sides thereof, the units being generally of the construction illustrated and described ininyco-pending application, Ser. No. 489,685 filed March 28, 1930.]y Each unit v is provided with a recess inits plate portion of a size sui'iicient to permit it to be lslipped over the trunnion and on to the carrier bar by a movement lengthwise of the bar and when in place on thev carrier, each unit is v held against dislodgment by portions thereof which underlie the lower edges of the carrier bar.

For a better understanding of the invention, reference may be had tothe accompany-` ing drawing, in which l i Fig. l isl a transverse sectionalviewsof the new grate bar; Y Y` wlig. 2 is a sectional view on the line 2-'2 of Fig. l; Y 100 Fig. 3 is a fragmentary view of the new bar in side elevation, showing the manner of removing one of the units;

Fig. 4 is a fragmentary plan view of one of the units; and Fig. 5 is a fragmentary plan view of the carrier bar with the units removed.

Referring now to the drawing, the carrier bar 10 is illustrated as being generally ofk inverted U-shape, each lug of the U having a laterally extending flange 11, which strengthens it and also serves another purpose presently tofbe described. Between. the legs of the carrier bar is a channel 12 into which air may enter and through the walls of the bar are a multiplicity of air ports 13 communicatingwith the channel. At each end the carrier bar has a portion offset upwardly therefrom and this portion terminates in a hollow trunnion 111-, the passage 15 through which communicates with thevchannel 12. The trunnions thus lie above the aXis of the carrier bar and the top of each trunnion lies above the top of the carrier bar. Since it is the inverted U-shaped portion of the carrier bar which is offset, that portion is narrower than the overall width of the carrier bar measured horizontally. The outer diameter of the trunnion is also narrower than the overall width of the carrier. At the top the trunnion is provided with a plurality of air ports 16 through the trunnion wall. Air entering the channel from beneath flows through the passage in the trunnion, cooling it and escaping upwardly through the ports 16 to the fuel above the trunnion. Near the ends of the carrier bar the flanges 11 thereon have an upwardly curved portion 17.

Mounted on the carrier bar are fuel-supporting units generally designated 18. Each unit comprises a plate portion 19 from both faces of which project spaced lugs 20. The spaces between the lugs provide passages 21 for upward flow of air and each lug is provided with a similar passage 22 in its outer face. The lugs are hollow and open at the bottom, as indicated at 28 so that air may flow up into the hollow interior of thelugs to cool them, the air escaping through an opening 24 in the plate between registering lugs on opposite sides thereof. Each lug may have a plain top but is preferably provided with a multiplicity of projections 25 separated by air channels 26, these channels communicating with the passages 21 and 22. The tops of the projections provide small fuel-supporting surfaces and each projection is surrounded on all sides by space through which air may flow so that the projections ar-erkept cool and prevented from burning out. Since the area at the top ofeach proj ection is relatively small, the fuel supported on the grate bar lies in contact only with. a small amount of solid metal and receives air on all sides o-f each of these small areas so that a highly efficient combustion is obtained.

Each unit is provided with a recess 27 in its lower surface having a shape somewhat similar to the section of the carrier member and at the lower end the recess is in part defined by inwardly extending lugs 28, the distance between the ends of which is less than the overall width of the carrier bar. The recess is large enough at its top to lie free of the top of the carrier bar and each unit thus rests on top of the flanges 11 of the carrier bar, as indicated at 29 and 30. Each trunnion is forinedon a radius not greater than the radius of curvature of the top of the inverted U-shaped portion of the carrier bar and while each unit is locked against accidental removal from the carrier bar because its lugs 28 are spaced a distance less than the Vwidth of the carrier bar across the flanges, the unit may be moved along the carrier bar to the end thereof and there removed. ln this operation, the unit is tilted slightly away from the inner face of the olset portion of the carrier'bar as indicated in dotted lines in Fig. 3 and by continuing the tilting, the lugs 28 may be brought out from beneath the upwardly curved ends of the flanges 11. rlhe spacing of the lugs 28 is slightly greater 'than the width of the upwardlyoffset portion of the carrier bar and slightly greater than the diameter' of the trunnion. Consequently Whenthe unit has been tilted so that its lugs 28 are free from beneath the flanges 11, the unit can be lifted clear of the carrier bar with the lugs 28 passing on opposite sides of the trunnion or on opposite sides of the' offset portion of the carrier bar. vAlso, since the recess 27 in the unit is larger than the trunnion, the unit may, if desired, be taken directly olf the trunnion. However, the possibility of lifting the unit off the carrier bar instead of sliding it off the end yof the trunnion is important since the units may be removed from the carrier bar while the latter remains in place in the grate frame with its trunnions received in the usual sockets therein. The curvature of the flanges' 11 at 17 permit 'the unit to be tilted to the Vdegree necessary' to permit lugs 28 to pass out from beneaththe ends of the flanges;

I am aware that it has been 'proposed to construct grate bars consisting of a carrier member and fuel-supporting units which are removable by movement lengthwise of the carrier bars and are held in place by portions which underlie the edges of the carrier bar. However, in all of these constructions with which I am familiar, the complete removability ofthe units from the carrier bar is accomplished by cutting away a portion of the carrier bar as, for example, the flanges 11, near one or both ends thereof, so that in removing a unit, the latter is moved along the carrier bar until it comes opposite this cutaway portion and is then withdrawn byla movement transverse to the carrier bar. This construction is objectionablefor several reasons, one being that the cutting away of the carrier bar produces a weak point at which the carrier bar is likely to break in service. Also, this cut-away portion usually lies in such position that one unit of theseries when in place on the bar-lies opposite the cut-out. As a consequence, this Vunit is not locked in position and in the shaking of the bar frequently becomes dislodged. In the present constructiomno unit can be removed except by a.movement'lengthwise of the bar and trunnion and when thegrate bar is in place in the grate frame,the engagement of the trunnions in the trunnion sockets of the frame prevents any ofthe units from being accidentally dislodged.

By mal-:ing the carrier member of the new bar of the Construction illustrated, the desired strength may be obtained without the use of heavy masses of metal. The lighten-` ing of the carrier bar by the formation of a channel in its under surface serves the additional useful purpose of permitting ventilation of the bar, air owing up into the channel from the ash pan and thence through the air ports of the fuel bed. By makingthe trunnions hollow, the desired strength is obtained without weakening the structure, and these trunnions are kept cool by air flowing therethrough from the channel, the air escaping either at the ends of the trunnions or else through the ports from the trunnion 'walls to the fuel above the trunnions.

The new bar when made of cast iron is substantially lighter per square foot of grate area than standard cast iron bars andV this lightness is achieved without weakening the bar. When made of steel, the new bar is lighter than an ordinary steel bar of the same area and by reason of the ventilation effect produced, the structure is prevented from sagging and its life is substantially lengthened.

lVhat I claim: Y

l. A grate bar comprising a longitudinal member having its end portions upwardly offset, trunnions projecting from the offset portions of said member, the tops of said trunnions lying above the top of said memher, and fuel-supporting units removably mounted on said membeneach unit having a recess to receive the member and having parts underlying portions of said member and preventing free upward removal of the unit from the member, said parts being spaced a distance greater than the diameter of the trunnion and greater than the width of the offset portions of said member, said` unit being removable by a'movement lengthwise of the member followed by a movement transverse thereto at such an angle as to cause said parts to pass on either side of the trunnion or of the offset portion at the'v having upwardly odset portions at its ends,

trunnions projecting from said offset portions, the tops of said trunnions lying above the top of said carrier bar and fuel-supporting units mounted on said bar, each unit having a recess adapted to-receive said bar, said recess being in part defined by spaced parts cooperating with said carrier bar to prevent removal of said unit' and said parts permitting removal of said'unit by a movement in which said spaced parts pass on either side of the offsetv portion of said carrier bar or on either side of a trunnion. y

3. A grate bar comprisingk a carrier bar terminating at vitsends in Vupwardly offset portions, trunnions projecting from said o'- set portions, the tops of said trunnions lying above the top of said carrier bar and fuelsupporting units mounted on said bar, each unit havino a recessA of a shape similar to the section of said carrier bar and having spaced lugs underlying portions of the carrier bar and preventing free upward removal of the unit therefrom, said lugs being separated a distance greater than the outer diameter of the trunnions and greater than the overall width of the offsetl portions of the carrier bar, the unit at each end .of the carrier bar being removable by a tilting movementbringing said spaced lugs from beneath said portions of the carrier bar followed by a movement at an angle to the axis of the carrier barvin whichsaid spaced lugs pass the trunnion on opposite sides thereof.

4. A grate bar comprising a carrier bar` having upwardly offset portions at its ends,

trunnions ro'ectinof from said-portions in 7 offsetV relation to said carrier bar, the tops of said trunnions lying above the top of the main portion of the carrier bar and fuelsupporting units on said carrier bar, each unit having a recess through which said carrier bar extends, and having spaced lugs underlying the side edges of the carrier bar, said lugs being spaced a distance greater than the outer diameter of the trunnions and Y greater than the width of the offset portions of said carrier bar, the end unit at either end of said carrier bar being removable by a tilting `movement bringing? its lugsA out from beneath theside edges of the carrier bar, followed by a movement at an angle to the carrier bar in which the lugs pass on opposite sides of the trunnion or of the Oifset portion at said end of the carrier bar.

5.V A grate bar comprising a carrier member of generally inverted U-section having laterallanges along the ends of the legs thereof,rthe carrier member having upwardly offset portions at its ends a plurality of fuel-supporting units on said member, each unitV havinga recessfthrough which said irc member extends' and Vportions underlying said flanges on the member, and trunnions projecting from the offset portions of said member, the tops of said trunnions lying above the top of said member, the Vunit at either end of said carrier'member being removable by a tilting movement to bring said portions thereof Vout from under the flanges on said member followed by a movement at an angle to the axis of Ysaid member in which said portions pass on opposite sides of the trunnion.

6. A grate bar comprising a carrier member having lateral flanges and trunnions at its ends, the tops of said trunnions lying above the top of the carrier member and said trunnions having an outer diameter less than the overall width of the carrier member across its flanges and a plurality of fuel-supporting units mounted on said member and having parts underlying said flanges, said parts preventing free upward removal of said units from the carrier member, the unit at either end. of said member being removable by a tilting movement to bring its parts out from under said flanges, followed by a movement at an angle to the axis of the carrier member in which said parts pass on either side of .a trunnion.

7. A grate bar which comprises the combination of a. carrier bar vhaving oflset trunnions at its ends, the tops of said trunnions lying above the top of the carrier bar and the carrier bar having a portion of greater width than the diameter of the Ytrunnions lying below the level of the trunnions, and a plurality of fuel-supporting units on said carrier bar, each unit having parts spaced a distance less than the width of said portion of the carrier bar and cooperating with the carrier bar to prevent free upward re.- moval therefrom, the unit at either end of the carrier bar being removable by a tiltingV movement to render said parts thereof ineffective followed by a movement at an angle to the axis of the carrier bar in which said parts pass on either side of one 'of said trunnions.

8. A grate bar which comprises the combination of a carrier bar having upwardly offset portions at its ends andtrunnions projecting outwardly from said portions with the tops of the trunnions lying above the top` of said Carrier bar, said carrier bar having a portion of greater width than the width of said offset portions and trunnions lying below the level of said trunnions, and a plurality of fuel-supporting units on said carrier bar, each unit having parts spaced aV distance less than the width o'f'said portionv and underlying the latter to prevent free upward removal of said unit-'from the carrier bar. the unit atY either end of the carrier bar be'- ing removablevtherefrom by a tilting movement in which said par-ts pass out from beneath said portion ofthe carrier bar followed by a movement at an angle to the axis of the carrier bar in which said parts pass on opposite sides of a trunnion.

9. A grate bar which comprises the combination of a carrier bar having upwardly offset portions at its ends, and trunnions projecting outwardly from saidportions and offset from the axis of said lcarrier bar, the top of said trunnions lying above the top of said carrier bar and said carrier bar having a portion of greater width than the width of said oifset portions and trunnions lying below the level ofthe bottoms of the trunnions, and a plurality of fuel supporting units on said carrier bar, each unit having a recess shaped to permit the unit to be mounted on said carrier bar with at least a portion of the latter passing through said recess, said unit also having parts spaced a distance less than the width of said portion of the carrier bar and preventing free upward removal of said unit from said carrier bar, .the unit at either end of said carrier bar being removable by'a tilting movement 'to cause said parts to pass out beyond the end of said portion of the carrier bar followed by a movement at an angle tothe axis of said carrier bar in which said parts pass on opposite sides of the trunnion and the offset portions at said end of the carrier bar.

In testimony whereof aiiix my signature.

Y JAMEs s. TnoMrisoN.

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