US2003154A - Fabricated damper - Google Patents

Description

May 28, 1935. P. s. MENOUGH FABRICATED DAMPER Filed Jan. 31, 1951 3 Sheets-Sheet 1 P41): 5 Mas 004M May 28, 1935. P. s. MENOUGH FABRICATED DAMPER Filed Jan. 51, 1951 3 Sheets-Sheet 2 Zlwpmatoc PAM. .2 Nth 006M May 28, 1935. P. s. MENOUGH 2,003,154

FABRICATED DAMPER Filed Jan. 31, 1951 3 Sheets-Sheet 3 7 m Z M M W W 4 Z w W a 1 j M 0 & a w w m M M g a M Nab M Patented May 28, 1935 UNITED STATES PATENT OFFICE to The Duraloy Com pany, Pittsburgh, Pa., a

corporation of Delaware Application January 31, 1931, Serial No. 512,638

4 Claims.

This invention relates to dampers or doors of the fabricated metal type for heating and annealing furnaces and like installations, and the primary object in view'is to simplify and lower the cost of construction and maintenance of closures of this class, and also reduce'the weight thereof. With this end in view, that part of the damper or door which is subjected to the greatest A heat from the hot gases or products of combustion, or the panel of the damper or door is removable and replaceable with respect to the frame, while the latter is characterized by its simplicity in construction. The removable panel member is preferably comprised of a heat and oxidation resistant alloy sheet metal which in its preferred form is corrugated to compensate for differential expansion and contraction, but which may be of any desired shape and may be comprised of a plurality of sheets with or without heat insulating material therebetween.

The frame of the damper or door is constructed of channeled sections which are preferably interfitted in dove-tail relation at the corners and welded, and the removable sheetmetal panel is then inserted between the side channels and into the groove of the bottom channel. The sheet metal panel may be sealed by a sand seal to render the damper or door gas-tight at the bottom edge of the sheet. The sheet may be detachably secured in place in any suitable manner. I Thus, if the sheet metal panel burns out while the frame, which is generally protected by thebrickwork of the furnace, still remains in condition for further usage, the said damaged panel may be removed and replaced by another new or reconditioned panel and the damper or door is ready for continued use. 7

The usual furnace damper or door as heretofore produced has been very heavy and rugged to withstand excessive heat from the products of combustion, and therefore expensive in construction. Such closure members are generallymade of comparatively heavy alloy castings connected with tie rods or are of the refractory lined and/or water cooled type. Both of these types are much too heavy and expensive in construction for many installations, and there is consequently considerable demand for a damper or door which is comparatively simple, light and cheap in construction.

The present form of damper or door is peculiarly adapted to meet this demand, and may also be used to advantage where relatively high heat conditions prevail, as even though the panel portion may burn out after being in use for some time, it

may be readily renewed and at a cost much lower than the original cost of the heavier types of dampers.

To gain a better understanding of the advantageous features of the improved damper; 5 reference is had to the accompanying'drawings; wherein:

Fig. l 'is a view in elevation of one form of furnace damper of the sliding type embodying the features of the invention, the guides for the 10 damper being shown in section;

Figs. 2 and 3 are enlarged'sectionalviews taken respectively on the lines 2-2 and 3-3, Fig. 1, the guides being omitted;

Fig. 4 is a sectional view taken on theline 4-4, 15 Fig. 1, the guides being shown in this figure;

Figs. 5 and 6 are enlarged detail fragmentary views in front and edge elevation of one of the upper corner portions of the damper;

Fig. 7 isa sectional View of one of the lower 20 corner portions;

Fig. 8 is a View similar to Fig. 1, illustrating a damper having a slightly different frame construction;

Figs. 9 and 10 are sectional views taken respec- 25 tively on the lines 99 and l0 l0, of Fig. 8; and Figs. 11 and 12 are sectional fragmentary views of corner portions of the damper;

Fig; 13 is a' sectional view of a modification in structure; V

Fig. 14 is a view in section and elevation showing a damper of the present improved type mounted to pivot in a frame;

Fig. 15 is a view in section taken on the line l5--I5 of Fig. 14, and

Figs. 16 and 1'7 are enlarged sectionalviews of portions of the frame structureof Fig. 14.

border to simplify the following description and terminology of the claims, the term closure or closure assembly has in general been adopted instead of the alternative expression damper or door.

Referring to the drawings, the reference nu-' meral 5 designates the top frame section, 6 the bottom section and l the side sections. These sections are of channel construction and are preferably comprised of cast alloy heat-resistant metal. At the corners, these frame sections interfit in dovetail relation and are preferably welded, the bottom corner construction clearly illustrated in Figs. 7 and 12.

The panel portion of the closure. assembly is indicated at 8 and consistsIpreferably of a.corru-- gated sheet-or in case of wide closure members, 7 of a series of overlapping sheets welded together,--of heat and oxidation-resistant alloy metal which is inserted in the grooves of the side frame sections 1 from the top of the closure member and slid down into the groove of the bottom section 6. The bottom groove may then be sealed with sand or the like as at 9 to prevent the passage of gas. The pressure of the gases or products of combustion presses the edges of the sheet against the side frame sections so that it will ordinarily notbe necessary to use a sealing medium at this point.

Any number of methods may be adopted'in securing the panel member or sheet 8 inplace so that it may be removed and replaced with comparative ease. In the form of closure assembly shown in Fig. l, the sheet is supported on the bottom section 6 and held in place at the top as illustrated in Fig. 5, the sections being secured in clamped relation on opposite sides of the sheet by bolts H a sealing strip H of suitable material being inserted between said sections on top of the strip. The strip H is preferably a thin strip slightly narrower in width than the space between the-side members of the top section. This strip rests on the top of the corrugated sheet and is free to expand and contract independently. Its function is to seal the gas passage around the top of panel member 8 formed by the corrugations of the sheet.

The corrugated shape of the sheet 8 is of advantage in that it provides for expansion of the sheet and particularly for differential expansion, and it is preferred to leave a clearance space between the sheet and groove walls sections to further accommodate this expansion.

At the top of the closure assembly, note Figs. 5 and 6, the side sections 'l are dove-tailed into the lower edge portions of the top sections 5 as at l2. The frame sections may be welded at this point, if desired, and the weld broken when the sheet 8 is to be removed. v

The closure assembly when assembled is insorted in guides 13 provided with attaching or mounting lugs l4. Very often when a tight closure member is not required, guides l3 are not used, the damper or door sliding up and down in slots in the brickwork comprising the sides of the flue. The top frame sections may be provided with an eye l5 by means of which the damper or door may be raised and lowered. The frame sections are also shown as provided with flanges or ribs l6, which contact with the walls of the guides l3. 7 Y

In Figs. 8 to 12 inclusive, a slightly different type of frame construction for the closure assembly is shown. In this instance the top frame section 50. is made or cast in one piece while the side and bottom frame sections may be interfitted and welded at the corners asflshown in Fig. 12 and the upper ends of the side frames provided with tonguesor like projections H which are bent over the top section 50. and welded thereto. In thisinstance the top frame section and the top'portion of the sheet 8 are provided with registering bolt holes to receive the bolts ID, the sheet 8 being thus suspended from the top section. This type of closure assembly is unusually light in weight and simple in construction. To remove the sheet 8, it is only necessary to break the weld at the tongues l1 and raise the top section 5a together with the sheet from its frame.

Fig. 1 3 shows a modification in structure. In thisinstance, a plurality of the sheets 8 are provided and are shown as either flat or corrugated of the frame and an insulating material 18 is placed therebetween. In this instance, sufficient clearance may be permitted adjacent the edge of the sheet to provide for expansion. It will be obvious that one or both sheets 8 may be corrugated, as for instance, the sheet which faces the interior of the furnace may be corrugated and the other sheet flat, as at 8a.

Figs. 14 and 15 show a further modification in frame construction and also the closure mounted to pivot in a frame l9 which may be seated in the brickwork of a furnace flue or like installation. In this instance the side and bottom frame sections are fitted together and welded at the corners as shown at 28 while the top corners are fitted together and a piece 17a welded over the corners. The sheet 8 is suspended as in Fig. 8 from the top section So by means of the bolts Hi. The bottom section 8 is provided with a trunnion 2' which has bearing in the bottom sill of the frame I9, while the top section 5a is formed with a socket which receives the one end of a control rod 22, the latter extending upwardly through the top of the frame 19 and also through a supporting frame 23 and having a control wheel or handle 24 secured thereon. Bearing supports or blocks 25 are provided on the frame 23. The inner sides of the frame I9 have flanges 26 attached thereto, the side frames 1 contacting therewith when the damper is turned to a fully closed position.

The same advantageous features are present in this'form of closure assembly as in the forms shown in Figs. 1 and 8, it only being necessary to break the corner welds at Ma to remove the panel portion or sheet 8 from its frame.

From the foregoing it will be seen that the improved closure member may be' comparatively light in weight, the side and top and bottom sections together with the removable panel 8 providing an unusually simple assembly of parts which may be manufactured at a relatively low cost. This reduction in weight is an important factor, as dampers and doors as heretofore constructed for this class of work have been very heavy and diflicult to handle. The advantages of'the removable and replaceable panel 8 will be obvious. As the frame sections of furnace damp ers are generally shielded by'the brick work, they do not receive the brunt of the heat as does the panel portion, and consequently the latter is often rendered unfit for use "long before the frame sections.

This picture frame construction also makes possible the use of a corrugated sheet of heat resisting alloy steel for the panel of the damper or door. In a large damper there will be different intensities of heat concentration over the sruface and consequently different degrees of expansion. In a flat damper this causes warpage which soon becomes so great that the damper will not operate. This construction is particularly advantageous in installations which operate at or above a red heat. Such a temperature demands a heat resisting alloy steel. Such a steel however has a very much larger coefficient of heat expansion than is the case with the low temperature cast iron usually used in damper construction and the warpage due to differential expansion would be greater. The use of a cormgated sheet for the panel of a damper admirably compensates for differential expansion and the tendency to warp is materially lessened.

It will also be obvious that the improved closure assembly may be hinged, pivoted or mounted invention as defined by the appended claims.

I claim:

1. A closure for furnace and like installations, comprising a frame section of cast alloy heat-resistant metal having dove-tailed channeled portions therein, panel also of heat-resistant metal allow detachably mounted in the channeled portions of said frame.

2. A closure for furnace and-like installations, comprising side and bottom frame members of relatively heavy cast metal with respect to the remainder of the closure, a top frame member detachably secured to said side members, and a panel member comprised of at least one integral heat-resisting alloy metal sheet removably associated with the side and bottom members and secured to the top frame member, said side and bottom members being secured together independently of said panel member and said panel member having its side edges positioned in grooves formed in the side frame members so that it may be withdrawn therefrom without dismantling the side and bottom frame members.

and a corrugated sheet metal 3. A closure member for furnace and like installations where relatively high temperatures prevail, comprising a frame having side, top and bottom sections of cast metal which are connected together at their corners, the side sec- 5 tions and the bottom section being grooved Ion.- gitudinally, a panel member consisting of one or more heat-resistant metal alloy sheets which have the side edges thereof slidingly engaged in the grooves of the side sections and the bottom edge seated in the groove of the bottom section, the sheet or sheets being thus rendered removable simply by disconnecting the top frame section, said sheet or sheets being formed with uniform longitudinally-extending parallel corrugations to permit expansion without distortion, and meansfor efiecting a seal between the edges of the sheets and the frame sections.

4. A closure for furnace and like installations, comprising a frame of cast metal, a panel of heat resisting vertically corrugated sheet metal asso ciated therewith and means for sealing the closure adjacent the top and bottom of the corrugated sheet panel.

PAUL s. MENOUGH.

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