US2340410A - Flue top - Google Patents

Description

flwucwto/o PHILL HANCELLOR P. CHANCELLOR FLUE TOP Filed March 12, 1940l Feb. l,y 1944.

mll' n Patented Feb. 1944 FLUE Tor l Phill Chancellor, salem, ohio Application March 12, 1940,.se1ia1N0. 323,556l

`(o1. QSL-cci i claim.

This invention relates to a flue top and more v particularly to a devicx'e for preventing down drafts in a vertically extending flue without in` teiferi'ng' substantially with the normal flow of air or gases through the flue. u

It is well known thatin various flue installations, particularly that of av chimney whose function is to carry away smoke and gaseous products of combustion, that certain meteorological conditions which interfere with the proper functioning of the flue arise from time to time to seriously interfere with the operation of the furnace, burners or other apparatus which the flue serves. These conditions often cause a downward surge or flow of air in the flue and it is the primary object of the present invention to provide an apparatus which will prevent such downward surges or ow of air under all conditions of weather and environment.

A further object of the invention is the provision of an apparatus having the characteristics pointed out above but which may be. economically constructed, readily applied to existing flues and which does not interfere with the normal functioning of the flue.

These and other objects and advantages of the invention should become apparent from a consideration of the following detailed specification and the accompanying drawing wherein there is specifically disclosed a preferred embodiment of the invention.

In the drawing:

Figure 1 is a side elevation of an apparatus constructed in accordance with the invention, the apparatus being shown as applied to a, con- .ventional flue, the latter being shown in section;

Figure 2 is a horizontal section of the apparatus taken along the line II--II of Figure 1; and

Figure 3 is a fragmentary sectional View taken along the line III-III of Figure 2.

The apparatus in its preferred and illustrated embodiment includes a sleeve I which is conveniently constructed of sheet metal and adapted to be received within the upper end of a vertically extending flue I6. It is desirable that the lower end of the sleeve I0 be'tightly received within the flue and in practice the peripheral contour of the lower end of the sleeve is similar to the inner shape of the particular flue to which the apparatus is to be applied.

Sleeve I0 is tapered inwardly toward its upper end and progresses in peripheral contour from the inner shape of the nue at its bottom to a circle at its top. Secured to the upper end of the sleeve I E! is a flat fiange II which extends out over the top end surface of the flue I6, thus providi'i'g a support for the apparatus.

- Extending upwardy from and securely fastened to the flange i I area plurality of inwardly curved Walls I3, preferably' four in number, which terminate short of each other to provide a` plurality of vertically extending openings 20 equally spaced about the outer periphery of the apparae tus'. A horizontally disposed ceiling member I5 is positioned on topof thewalls I3, being preferably also constructed of sheet metal, and fastened to thewalls by any suitable expedient. A conical roof I li overlies the ceiling i5 and completes the apparatus. It should be observed that the roof I4 extends outwardly beyond the walls I3 and the openings 20 and this, together with the corneal shape of the roof, diverts any downward ow of air from the passages leading to the flue I6.

The operation of the apparatus described above should be readily apparent. In the event of a downward flow of air in the apparatus environment, the roof I4 will function to divert the now away from the vertical openings 20 leading to the space within the flue. If the flow of air is directed angularly downwardly the substantial part of the flow will again be diverted by the roof and only that portion which can enter one or two of the openings 2l] will pass into the apparatus. This component, however, will be deflected upwardly by the flat surface of the ange I I and will be drawn out of the apparatus through the other of the openings 20. The flat surface of the flange II cooperating with the flat and uninterrupted ceiling I5 provides an unrestricted passage for the horizontal movement of air through the apparatus and eliminates recesses and pockets which would cause the air to swirl and build up a positive pressure in the apparatus which would result in a down draft. By referring to Figure 2, which indicates by means of arrows the horizontal component of ow through the apparatus, it can be observed that quantity of air entering the apparatus is determined solely by the frontal areas of the openings 20 presented to the direction of air flow. This total area is small in proportion to the total obstructional area of the apparatus and is definitely less than the effective area of the other of the openings 20. By reason of the curvature `of the side walls I3 the said effective area is at all times subjected to an exhausting force and, therefore, the average pressure within the ring I2 where the sleeve I0 meets the flange Il 2- v 2,340,410 i t f f will always be less than the average pressure of the atmosphere immediately surrounding the apparatus and this, of course, insures the proper functioning of the ue under all conditions.

Figure 2 illustrates a condition where the flow of air is directed toward one of the openings 20 and in this situation the volume of air passing into the apparatus is determined by the crosssectional area of the one opening. Theoretically we can assume that this volume of air passes directly through the apparatus and exhausts therefrom at the opening diametrically opposite. The air impinging against the inwardly curved walls i3 immediately adjacent the first named opening will be caused, by reason of theA curved surfaces, to be diverted outwardly along the outer reaches of the curved surfaces and as these volumes of air move past those openings 20 which are at right angles to the first named opening, the air and gases within the apparatus will be sucked out through those openings.

The above specificallyv described embodiment of the invention should be considered as illustrative only as obviously many changes may be made therein without departing from the spirit or scope of the invention as dened in the appended claim.

The term flue as used throughout the specification and claim is to be taken asmeaning any channel or passage for smoke, air, gases of combustion or other gases as the invention is equally applicable to these various uses. For example, the apparatus of the invention may be advantageously applied to the discharge end of a Ventilating duct or shaft.

What I claim is:

Apparatus of the character described comprising in combination an upwardly tapering sleeve adapted to fit within the upper portion of a flue, a portion of said sleeve having a peripheral contour corresponding to the inner shape of the ilue whereby the sleeve may be closely fitted within the flue, a flange secured to the upper end of said sleeve and adapted to overlie the top end of said flue, a plurality of side Walls extending upwardly from the outer portion of said ange, said Walls terminating short of each other to provide a plurality of circumferentially spaced but diametrically opposed vertically extending openings unobstructed in laterally or horizontally outward directions to allow unimpeded flow of air transversely through an opposed pair of said openings and across the open top of said sleeve,V said walls being curved about-vertical axes' positioned outwardly of and intermediate said openings, the radius of curvature of said Walls being greater than half the mean lateral dimension of the flue opening whereby a portion of an air flow impinging laterally on said walls will be deflected outwardly to create a suction Vabout certain of said openings which are circumferentially spaced from said opposed pair of openings, and a roof over said Walls extending outwardly of said walls.

PHILL CHANCELLOR.

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