US2517446A - Fog suppressing gas burning heater system - Google Patents

Description

FOG SUPPRESSING GAS BURNING HEATER SYSTEM 2 Sheets-Sheet 1 Filed NOV. 5, 1945 @ff/lla@ @ams gym Ms Aug. 1, 1950 F. A. RYDER ErAL Eos sUPPREssING GAS BURNING HEATER SYSTEM 2 Sheets-Sheet 2 Filed Nov. 5, 1945 Patented Aug. 1, 1950.

UNITED STATES PATENT OFFICE FOG SUPPRESSING GAS BURNING HEATER SYSTEM Application November 5, 1945, Serial No. 626,604

This invention relates generally to heating systems, and more particularly to improved heating systems for small buildings.

It is customary to provide a chimney or stack for carrying away the products of combustion of a furnace or other heater, even in the case of heating systems particularly adapted for use in small buildings. A chimney represents a considerable proportion of the cost of a building. The proportionate cost of a chimney in a small building is especially high, and the elimination of the need for a chimney in such buildings results in a great saving in construction costs. The heating system of the invention provides for the discharge of the products of combustion into the exterior atmosphere through the side wall of the building, thus making it unnecessary to provide a chimney, and yet providing for the positive flow of such products from the heater. With such an arrangement, there is objectionable condensation of moisture contained in the combustion products upon contact with the relatively cold outer air. This is particularly true of gas fired heaters. To prevent the possibility of such condensation, meansare provided in the present `heating system so that condensation does not occur upon such contact.

It is an object of this invention to provide an improved heating system, particularly adaptable for heating small buildings, which eliminates the need for a chimney.

Another object is to provide an improved heating system particularly adaptable for small buildings in which means areprovided for discharging products of combustion through a side wall of the building.

A further object is to provide an improved heating system, particularly adaptable for small buildings, discharging the products of combustion through a side wall of the building, in which means are provided to prevent the formation of a cloud of condensed vapor at the exhaust outlet. i

It is also an object of the invention to provide a heating system discharging products of combustion through a side wall of a building to the exterior thereof and having means for diffusing the products of combustion through an air stream for discharge in mixed condition therewith. v

Other objects and advantages of the present invention will become apparent from the ensuing description of an embodiment thereof, in the course of which reference is had to the accom-- panying drawings, in which:

2 Claims. (Cl. 158-7) Fig. 1 is a central vertical sectional view through the heater, with parts in elevation and parts in fragmentary section;

Fig. 2 is a horizontal cross sectional view taken substantially along the line 2 2 of Fig. 1, with parts in elevation and parts in fragmentary section; and

Fig. 3 is a fragmentary elevational view taken substantially along the line 3--3 of Fig. 2, with parts in fragmentary section.

This invention is in the nature of an improvement on the heating system disclosed in the copending application Serial No. 596,130, filed May 28, 1945, by Theodore Y. Korsgren and Frank A. Ryder and now abandoned.

The heater is illustrated as comprising a substantially cylindrical housing Ii! suitably secured at its upper edge to a flange il. The flange is shown as circular in shape and is secured to the flooring It by screws not shown. A register l2 covers the opening in the floor and is supported by a horizontal ange portion lll. The register has a plurality of sloping baies IB, the spaces between the central baliles providing ports for the discharge of heated air as indicated by the upwardly directed arrows in Fig. 1, while the spaces between the outer bales provide ports for the admission of Ventilating air, as indicated by the downwardly directed arrows. Since the upward flow of heated air is at a substantial velocity, the heated air will be forced into the room while cool air will iiow along the floor and downwardly between the outer bailles.

Filters 2i! may be provided to remove foreign matter from, the downwardly moving air. Each lter may comprise a pair of spaced foraminated plates 22 between which a suitable filtering material 24 is disposed. The iilters 2li may be supported between an upper apertured rectangular plate 26 and a lower apertured partition plate 23 to cause the entering air to flow through the filters in the directions indicated by the arrows.

The heating unit comprises a casing 3B of generally cylindrical shape having an adapter 32 at the top thereof providing a generally rectangular outlet. A flaring pipe section 3ft of rectangular cross section is secured to the adapter 32 and is provided with deflectors 36 at its upper end. The casing 3!) has its lower end joined to an inlet extension 38 which has legs lil resting upon the bottom wall 42 of the housing` Iii. A heat exchanger 44 is suitably mounted in the casing 3U. The heat exchanger is shown as being of the spiral type wherein the products of combustion ow `spirally outwardly from a center chamber 3 46 through a spiral passageway 48 to an exhaust or outlet tting 50, this fitting extending through the housing l0.

Combustion takes place within a combustion chamber 52 secured to the heat exchanger M and communicating directly with the center chamber 4t thereof. l In the particular heater shown, domestic gas is used as the fuel and is supplied through a pipe 513. Gas is supplied to a pilot burner 55, projecting into the combustion chamber, through a conduit 58. Gas for normal combustion is supplied to a main burner nozzle 63 through a conduit S2. The flow through thereonduits 58 and 62 is controlled by suitable valve mechanisms @il and tt, respectively, which may be of the solenoid-actuated type well known in the art. A spark plug 68 having its electrode within the combustion chamber 52 may be employed to effect ignition of the pilot flame.

Circulation of Ventilating air through the heater is induced by a fan 'IB driven by a motor l2 suitably supported from the legs iii). The fan draws cool air downwardly through the :housing I3 about .the casing 33 and blows it upwardly through the spiral passageway formed by the walls ofthe exl'iaust passageway 48 `and the casing 30, as indicated by the arrows in Fig. 1.

A thermostat (not shown) may be employed to control the operation of the main burner te and fan 'it to maintain a vdesired temperature in the room or building being heated. A manual control rod M may be provided for starting and stopping the operation of the heater as desired, this control rod controlling energization ci the spark plug 65 and flow of gas through the pilot flame control valve mechanism til. As shown in 1, the rod it may actuate both a lever l5 for controlling electric switches in a box i8, and a lever I9 for opening and closing a pushbettom type valve 82 in the valve mechanism 54.

An exhaust pipe et is connected 'by a suitable adapter fitting 83 to the outlet tting tti, and, as shown in Fig. 2, extends substantialiy horizontally to a side wall 84 of the building. A `discharge conduit S6 jackets the exhaust pipe Bil, having one end closed and secured to the exhaust pipe an adapter '38 adjacent the heater. rEhe other end of the discharge conduit t@ projects beyond the discharge end of the exhaust pipe tt, and extends `through the wall so as to vent to the exterior atmosphere. The exhaust pipe 89 and discharge conduit Sii may be held in suitably spaced relation by spacing means (not shown) of any suitable type. By this arrangement, no chimney or vertical flue is required in the building, 'since the exhaust gases are led through a relatively short conduit from the heater to the open air. The fiow of exhaust gases is not hindered by the absence of ra vertical passage therefor', Vso that the efficiency of the heating system is not lowered. At the same time, `the construction cost of the building is reduced, and the trouble and expense incident to the cleaning and maintenance of a chimney is avoided. The construction just described, therefor, by which the exhaust gases kare discharged horizontally through a side wall instead of vertically through the roof, is distinctly advantageous.

lidiffuser '99 is connected to the discharge end of the exhaust pipe St, and may suitably take the form of a perforated cap, although itmay be of any other desired construction as, for example, an open tubular member with perforations in the wall thereof. A baille plate 92 is secured in the conduit 86 between the Vopen end thereof and the diffuser 90 to cause turbulence and thereby promote better mixing.

An air inlet conduit 9d has one end thereof extending through the wall 84, with the other end connected to a flaring adapter fitting 96 which leads to the housing S8 of a blower -I driven by motor 62. The latter may -be supported from the housing ill by a suitable bracket l |34. A suitable adapter IDS connects the blower housing 98 with two conduits Hi8 and Ht, a portion of the air drawn through the inlet conduit 94 being forced through each of these conduits |03 and I lil by the blower The conduit ISB leads to the combustion chamber 52 to conduct air for combustion to the burner. The products of com bustion pass from the burner into the center chamber fit and through the spiral exhaust passageway lit, outlet fitting 5t, and adapter fitting e3 into the exhaust pipe 8G;

The conduit lill leads from the blower to the discharge conduit 843, being connected thereto in any suitable manner adjacent the `closed end thereof, as by means of a branch 8l of the conduit S6. A portion of the air drawn through the inlet conduit 94 thus by-passes the heater vand flows through the discharge conduiti and around the exhaust pipe Se to vent to the atmosphere. In its passage through the discharge'conduit 85, this air, which may conveniently be termed diluent air, niingles with the products of combustion `issuing from the exhaust pipe through the diffuser de, the mixing of the exhaust gases and diluent air being promoted by the restriction provided `by the baiile plate 92. The mixture flows past the baffle plate 92 to the atmosphere. The portions of the discharge conduit 86 and the inlet conduit 94 which project through the wall 813 may conveniently be disposed adjacent-each other, sothat a single opening in the wall may accommodate both conduits. A screen or iilter l t3 maybe provided in the inlet conduit 96 to bar the ingress of foreign bodies. A suitable shield `or hood (not shown) may be provided to shield the open ends of the conduits 865 and 9d from rain andthe like.

The exhaust gases or products of combustion produced in the burner and passing through the exhaust pipe contain a high proportion Aof moisture. The exhaust gases are at an elevated temperature, and this elevated temperature com,- bined with the high moisture content results in the gases having a relatively high dew point. If the exhaust gases are discharged directly into the relatively cold outside air, normally Apresent during the operation of a heating system, an objectionable cloud of condensed vapor might-form immediately adjacent the outlet and the wall l84 of the building unless the exhaust gases are very hot. In the apparatus described, the addition of diluent air at the diffuser 90 and the provision of baille plate 92 prevent such cloud formation. The diluent air and exhaust gas mixture has a temperature somewhat lower than that of the exhaust gases, but still considerably higher than the outside atmosphere. The mixture also 'has a somewhat lower proportion of moisture than the exhaust gases, since the diluent air does not contain 'as large a proportion of moisture as do the exhaust gases. The relative humidity of the mixture of diluent air and exhaust gases is therefore lower, resulting in a lower dew point for the mixture. When this mixture of lower dew point passes into the outer atmosphere, none or very little vapor condenses, and no vapor cloud is formed.

The cloud preventing effect depends upon the temperature of the exhaust gases and the quantity and humidity of diluent air. The higher the exhaust gas temperature, and the greater the quantity of air mixed therewith within limits, the better the results obtained. This general statement of the principle involved is subject to limitations imposed by practical considerations, but most satisfactory results are obtained Within these limitations by applying the two factors mentioned, that is, the high exhaust gas temperature and the quantity of diluent air, in varying combinations. Increasing the exhaust gas temperature and increasing the quantity of di1- uent air both tend to decrease the over-all efficiency of the heating system, and it is therefore desirable not to increase the exhaust gas temperature or the diluent air flow rate more than necessary to prevent the clouding eifect.

As an example, we have found that with an exhaust gas having a temperature of between 500 degrees and 600 degrees Fahrenheit the addition of about 20 to 30 per cent diluent air is sufcient, if the exhaust pipe is short. Without any diluent air much higher exhaust temperatures would be necessary.

The maintenance of a high temperature in the exhaust gases is assisted by the flow of diluent air about the exhaust pipe, which results in insulating the exhaust pipe against substantial heat loss. Most of the heat lost by the exhaust gases is transferred to the diluent air, which is of advantage since it is not lost to the system inasmuch as the diluent and exhaust air are to be mixed eventually anyway. Therefore, the temperature of the mixed gases at the discharge end of the pipe 30 is only slightly less than they would be at the outlet fitting 50. The diluent air thus serves both to conserve the heat of the exhaust gases until the zone of mixing adjacent the diffuser 90 and baffle plate 92 is reached, and to produce with the exhaust gases a mixture of high temperature and low relative humidity and consequent loW dew point, as already explained. In order to get the full benet of this insulating effect, especially with long thin exhaust pipes.

more diluent air should be used than proposed above. For instance, with a pipe fifteen feet long, as much as 200 per cent diluent air can be used to advantage.

Instead of jacketing the exhaust pipe by the discharge conduit 86, the exhaust gases and the diluent air may be conveyed separately to a mixing fitting or chamber and discharged therefrom to the outer atmosphere, if desired. In this case, the diluent air would not jacket the exhaust pipe and provide heat insulation therefor, and accordingly it would be desirable to insulate the exhaust pipe against heat loss.

With exhaust pipes which are relatively short, the mixing of diluent air and exhaust gases may take place at a point quite close to the heater. In such case, the jacketing of the short length exhaust pipe 3B by the discharge conduit 86, or the insulation thereof by other means, would be unnecessary. It appears that the location of the mixing zone relatively close to the outlet to the atmosphere is the important consideration. If this location is relatively remote from the heater,

6 provision should be made to minimize the heat loss from the exhaust pipe, while if this location is close to the heater as well as to the outlet, the heat loss is so slight as to render unnecessary any insulation of the exhaust pipe.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. In a heating system including a gas burner, an exhaust pipe to conduct `products of combustion including a high concentration of water vapor from said burner, a fog suppressing system comprising a perforated extension on the discharge end of said pipe for diffusing said products, a conduit surrounding said pipe for substantially its full length and terminating in the outside atmosphere in a venting end beyond said extension, means restricting the interior of said conduit intermediate said extension and said venting end, and means to force air through said conduit about said pipe and extension in the direction oi flow of said combustion products, the last said means introducing said air into said conduit adjacent said heater, whereby heat insulation is provided for said pipe and said combustion products and air are intermingled in the vicinity of said extension and restricting means to provide a low dew point mixture for discharge to the atmosphere.

2. In a heating system including means forming a combustion chamber and a gas burner therein, a pipe connected to said combustion chamber for exhausting combustion products having a high concentration of water vapor therein from the combustion chamber, a conduit surrounding said pipe for substantially its full length and terminating in the outside atmosphere to define an annular space between said conduit and said pipe, means to force cold atmospheric air into said annular space adjacent said combustion chamber, and means at the outlet end of said exhaust `pipe for mixing air from said conduit with the products of combustion from said exhaust pipe adjacent the termination ot said conduit and for exhausting said mixture to the atmosphere.

FRANK A. RYDER. THEODORE Y. KORSGREN. ARTHUR Rf. COLLINS.

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

UNITED STATES PATENTS Number Name Date 345,107 Brinkerhoi July 6, 1886 1,353,740 Gillespie Sept. 2l., 1920 1,604,271 Friedman Oct. 26, 1926 1,629,921 Mansfield May 24, 1927 1,773,870 Schmidt Aug. 26, 1930 1,869,939 Latimer Aug. 2, 1932 2,286,855 Holthouse June 16, 1942 2,385,652 Rifle Sept. 25, 1945 FOREIGN PATENTS Number Country Date 234,896 Great Britain June 4, 1925

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