US2557210A - Draft controlling and back draft - Google Patents

Description

June 9 v P. A. VIOLA ET AL 2,557,210

DRAFT CONTROLLING AND BACKDRAFT DIVERSION DAMPER DEVICE FOR FURNACES Filed May 4, 1948 3nventors 4. 724, (IttorneBS Patented June 19, 1951' UNITED DRAFT CONTROLLING AND BACK DRAFT DIVERSION DAMPER DEVICE FOR FUR- NAG-ES Paul A. Viola and Joseph A. Viola, Bridgeport, Conn.

Application May 4', 1948, Serial N 0.. 24,954

Claims.

This invention relates to a draft control for furnaces. It could be used with practically any type of furnace, but is designed primarily for oil or gas: furnaces, and has for an object to provide a simple and effective device for preventing the downdraft from the chimney passing back into the furnace to possibly blow out the flame or force the gases or products of combustion out into the room.

Another object is to prevent the circulation of cooling air through the furnace to absorb heat and carry it up the chimney when the burner is not operating.

With the foregoing and other objects in view, we have devised the construction illustrated in the accompanying drawing forming a part of this specification. It is, however, to be understood the invention is not limited to the specific details of. construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In this drawing:

Fig. 1 is a partial side elevation and partial section showing use of the device in. a furnace;

Fig. 2 is a longitudinal vertical section through the device taken on substantially the line 2-2. of Fig. 4;

Fig. 3 is a horizontal longitudinal section taken substantially on line 33 of Fig. 4, and

Fig. 4 is an end view looking from the left of Fig. 2.

A furnace of any desired type is indicated at 5, with the usual smoke pipe 6 and any type of oil burner indicated diagrammatically at 1. It is, however, to be understood this is shown merely by way of example, as the device may be used with other types of burners, such, for example, as gas or coal burners. In the pipe is the usual thermostat 8 operating limit switch 9 to turn off the burner when the heat reaches a certain amount, and mounted in this pipe, preferably in the last section as it enters the chimney l 0, is our device indicated as a whole at H.

The device comprises a section of stove pipe l2 adapted to be inserted at the outlet end in the opening to the flue of the smoke-stack or chimney, and at its other end telescoping with the next standard stovepipe section 6. Within this section I2 is a tapered section I3 which may be made of the sheet metal used for making standard stovepipe and the section [2, and this tapered section is of a size so that its larger end l4 fits and is secured in the section l2 adjacent the end nearest the furnace, with its outlet or smaller end I5 adjacent the discharge end of the section I2.

2 This outlet is controlled by a light hinged damper i5. pivotally mounted. on the top of the tapered section by any suitable. means, such, for example, as asubstantially U-shaped bracket I! which may be secured by any suitable means. on the top of the tapered section.

The damper is mounted on a pivot rod l8 extending at one end through the side of the section l2, where it is bent laterally to form a rearwardly extending arm I8a on which is adjustably mounted a counterweight 49 which is adjustable along the rod and may be secured in any adjusted position by the set screw [9a. The rod is formed with an intermediate bend 20 to limit forward movement of weight i9 so that should the weight [9 become loosened or should a child or someone adjust it on the rod, it could not move nearer than this bend to the pivot, so that the damper could not overbalance this weight sufficiently that the damper would not open by draft from the furnace. There may be a small Weight Zl mounted in the damper if it is found the damper itself is not of sufficient weight for the counter-balancing effect, and although the damper may be of other shapes it is preferably substantially conical as shown.

The weight I 9 is so adjusted that with no fire in the furnace the damper l6 will just close, so that a very light draft will open the damper, as indicated by the dotted line in Fig. 2, as soon as the burner is lighted or becomes operative, but any down or backdraft will close this damper so that. it will not blow or flow back into the furnace to blow out the flame of the burner or to force the products of combustion or other gases out into the room. To further assist this action, the outer section i2 is provided with openings 22 on opposite sides and just forwardly of the larger or entrance end of tapered section I3, so that the downdraft flowing toward the furnace, after closing the damper I6, will pass out through these openings 22. These openings also permit air to pass into the pipe during normal operation to help control the draft and to keep it more uniform.

A still further important operation and effect of this device is that when the burner is not operating, as for example, when the temperature has reached a certain limit, as effected by the usual automatic thermostat controls, this damper closes and prevents the fiow of cold air through the furnace and up the chimney, which flow of cold air would, of course, have a cooling eifect on the furnace and carry a considerable amount of heat up the chimney. It therefore effects a greater efficiency in operation of the furnace and a material saving in fuel by preventing this loss up the chimney. This, in addition to the safety features as described and better control of the draft, has made this device very eifective in actual use. Due to its simplicity it can be manufactured at relatively low cost and is easily installed in the smoke pipe.

Having thus set forth the nature of our invention, we claim:

1. A draft control for furnaces comprising a section of stove pipe adapted to form a, portion of the smoke pipe from the furnace to the chimney, a tapered section in the first section arranged with its larger end fitting the inside of the first section in substantially gas tight relationship therewith and its smaller end spaced substantially inwardly of the inner surface of the first section, said tapered section being hollow and open at both ends to provide a gas passageway entirely therethrough, a pivoted damper at the smaller end of the tapered section, means balancing the damper to swing outwardly away from this end under the influence of a draft from the furnace and to be swung by a back draft to close the opening upon the occurrence of a reverse draft, and the first section being provided with air inlet means leading to the space between this section and the tapered section.

2. A draft control for furnaces comprising a section of stove pipe adapted to form a portion of a substantially horizontal smoke pipe leading from the furnace to the chimney, a tapered section in the first section open at both ends to provide a gas passageway entirel therethrough and arranged with its larger end forming the inlet end and the smaller end the outlet, the larger end fitting the inside of the first section in substantially gas tight relation therewith and the smaller end spaced substantially inwardly of the inner surface of the first section, a pivoted damper over the smaller outlet end, a lateral arm connected to the damper, a balance weight adjustably mounted on said arm, said damper being arranged to swing outwardly from said smaller end under influence of a draft from the furnace and to be swung back to close the opening by a back draft from the chimney, and the first section being provided with air inlet openings leading to the space between this section and the tapered section.

3. A draft control for furnaces comprising a section of stove pipe adapted to form a portion of a substantially horizontal smoke pipe leading from the furnace to the chimney, a, tapered section in the first section open at both ends to provide a gas passageway entirely therethrough and arranged with its larger end fitting the outer section in substantially gas tight relationship therewith and its smaller end forming the outlet spaced substantially inwardly of the inner surface of the first section, a damper over the outlet end, means pivotally mounting said damper on the tapered section to swing outwardly away from said smaller end under the influence of a draft from the furnace nd to be swung by a back draft to close the opening in said smaller end upon the occurrence of a reverse draft, said mounting means comprising a pivot rod including a laterally extending arm, a balance weight adjustably mounted on the rod, said rod being provided with a stop means for said weight between the weight and pivot portion of the rod to limit movement of the weight toward this portion, and the outer section being provided with air inlet openings leading to the space between this section and theinner tapered section.

4. A draft control for furnaces comprising a, section of stove pipe adapted to form a portion of the smoke pipe from the furnace to the chimney, a tapered section in the first section open at both ends to provide a gas passagewa entirely therethrough and arranged with its larger end fitting in the outer section in substantially gas tight relationship therewith, and its smaller end spaced substantially inwardly of the inner surface of this first section, a pivoted damper closing the smaller end, means balancing the damper so that it will move outwardly away from said end to open position under the influence of a draft from the furnace and will be swung back to close the opening upon the occurrence of a reverse draft from the chimney, and the outer first section being provided with air inlet openings adjacent the larger end of the tapered section leading to the space between the outer and tapered sections.

5. A draft control for furnaces comprising a section of stove pipe adapted to form a portion of the smoke pipe from the furnace to the chimney, :a tapered section in the first section open at both ends to provide a gas passageway entirely therethrough and arranged with its larger end forming the inlet end and the smaller end the outlet, the larger end fitting the inside of the first section in subtsantially gas tight relationship therewith and the smaller end spaced substantially inwardly of the inner surface of the first section, a pivoted damper over the smaller outlet end, a lateral arm connected to the damper, a balance weight adjustably mounted on said arm, said damper being arranged to swing outwardly away from said smaller end under the influence of a draft from the furnace and be swung by a back draft to close against said end upon the occurrence of a reverse draft from the chimney, and the outer section being provided with air inlet openings adjacent the larger end of the inner section leading to the space between the outer and inner sections.

PAUL A. VIOLA. JOSEPH A. VIOLA.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 80,832 Pastorius Aug. 11, 1868 1,196,117 Kiefer Aug. 29, 1916 1,856,478 Greenberg May 3, 1932

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