US3393903A - Space heater - Google Patents

Description

July 23, 1968 C. A. BERGLUND, JR

SPACE HEATER Filed June 29, 1966 Inventor CARL A. BERGLUND, J'R.

July 23, 1968 i c. A. BERGLUND, JR 3,393,903

SPACE HEATER 2 Sheets-Sheet 2 Filed June 29. 1966 ATTYS United States Patent O 3,393,903 SPACE HEATER Carl A. Berglund, Jr., Vermillion, S. Dak., assignor, by

mesne assignments, to Dura Corporation, a whollyowned subsidiary of Walter Kidde & Company, Inc.,

Oak Park, Mich., a corporation of New York Filed June 29, 1966, Ser. No. 561,623

22 Claims. (Cl. 263-19) ABSTRACT OF THE DISCLOSURE This invention relates to a space heater in which a generally cylindrical outer casing is provided together with a generally cylindrical inner casing disposed within the outer casing and spaced therefrom to define a longitudinally extending heat exchange channel therebetween. The inner casing defines a fuel combustion chamber and has associated therewith a fuel nozzle mounted substantially on the longitudinal axis of the inner casing adjacent to one end `thereof and connected to a fuel pump to inject a stream of fuel into the combustion chamber generally along the longitudinal axis thereof. A fan mounted within the outer casing directs a stream of air along the outer casing toward the one end. of the inner casing in a direction substantially parallel to the longitudinal axis of the casings. There is an adjustable baffle structure mounted within and adjacent to the one end of the inner casing which divides the air stream into a first portion directed inwardly into the inner casing and around the nozzle and a second portion directed outwardly into the heat exchange channel and along the facing surfaces of the casings. An electrical ignition system supported adjacent the nozzle provides means for igniting the fuel-air mixture resulting from the mixing of the fuel and the first portion of air to cause combustion thereof within the combustion chamber in a combustion zone therein. A bafiie structure positioned at the end of the inner casing remote from the first mentioned baffle structure permits the products of combustion to exhaust therefrom and at the same time maintains a back pressure on the combustion zone. The first mentioned baie structure is adjustable t vary the amount of air entering the combustion zone and adjustment is also provided to vary the back pressure provided by the second baiiie structure. The baffle structure adjacent the nozzle also includes directing air vanes or fins directing the first portion of the air stream inwardly toward the nozzle and imparting a swirling motion to the said first portion of the air stream.

The present invention relates to space heaters, and particularly to improved air supply control systems therefor and to an improved combustion zone limiting baffle structure incorporated therein.

The present invention is particularly adapted for use in a space heater of the type including a generally cylindrical outer casing and a generally cylindrical inner casing disposed within the outer casing and spaced therefrom to define a longitudinally extending heat exchange channel therebetween, the inner casing defining therein a fuel com bustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of the inner casing adjacent to one end thereof and connected to a fuel pump to inject a stream of fuel into the combustion chamber generally along the longitudinal axis thereof, a fan for creating a stream of air directed along the outer casing toward the one end of the inner casing in a direction substantially parallel to the longitudinal axis of the casings, a bafiie structure mounted adjacent to the one end of the inner Casing and dividing the air stream into a first portion directed inwardly into the inner casing and around the noz- 3,393,903 Patented Jiuly 23, 1968 zle and a second portion directed outwardly into the heat exchange channel and along the facing surfaces of the casings, and an ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel and the first portion of air to cause combustion thereof within the combustion chamber in a combustion zone therein.

It is an important object of the present invention to provide in a space heater of the type set forth a valve plate cooperating with the baiiie structure and adjustable with respect thereto for adjusting the proportion between the first and second portions of the air stream.

In connection with the foregoing object, another object of the invention is to provide an improved baie structure comprising a plate disposed in one end of the casing from the inner casing and having an opening centrally therein to receive the nozzle and a plurality of openings around the periphery thereof for receiving the first portion of the air stream therethrough, there also being provided a plurality of iins mounted on the baffle and directing the iirst portion of the air stream inwardly toward the nozzle and imparting a swirling motion to the first portion of the air stream.

Yet another object of the invention is to provide in a space heater of the type set forth a second baflie structure mounted adjacent to the other end of the inner casing and directing the first portion of the air st-ream and the combustion products carried thereby back toward the one end of the inner casing to confine the combustion zone of the burning fuel-air mixture toward the one end of the casing and -positively to prevent the escape ofl tiames from the other ends of the casings.

Still another object of the invention is to provide an improved space heater of the type set forth wherein the fuel pump, the drive motor for the fuel pump and the fan, the fan and the adjacent end of the inner casing are all mounted in longitudinal alignment within the adjacent end of the outer casing, whereby the fan draws cooling air over both the fuel pump and the drive motor to preheat the air and to cool the ypump and the drive motor.

A further object of the invention is to provide an improved space heater of the type set forth having a fuel tank disposed beneath the outer casing and supporting the same, the fuel tank also preferably being provided with wheel structure to permit ready portability of the space heater.

Further features of the invention pertain to the particular arrangement of the parts of the space` heater whereby the above-'outlined and additional operating features thereof are attained.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specitication taken in connection with the accompanying drawings, in which:

FIG. 1 is a side elevational view of a space heater made in accordance with and embodying the principles of the present invention;

FIG. 2 is an end view with certain portions removed of the space heater of FIG. 1 as viewed from the right;

FIG. 3 is an enlarged fragmentary view with certain portions broken away showing the combustion chamber and heat exchanger forming a part of the space heater of FIGS. 1 and 2;

FIG. 4 is a fragmentary View in vertical section along the line 4-4 of FIG. 3; and

FIG. 5 is a view in horizontal section along the line 5-5 of FIG. 4.

Referring to FIGS. 1 and 2 of the drawings there is illustrated a space heater made in accordance with and embodying the principles of the present invention. The space heater 100 includes a generally cylindrical fuel tank 101 supported for ready portability upon a pair of wheels 110 and a skid 115, the fuel tank 101 supporting thereon concentric casings 120 and 130 providing an air duct and a combustion chamber for the space heater 100. Fuel in the tank 101 is taken therefrom by means of a pump 165 driven by a motor 170 and forced through a nozzle 160 into the inner casing 130; simultaneously a fan 175 also driven by the motor 170 forces air into the inner casing 130 to mix with the fuel therein and to burn thus providing heat. The now heated stream of air from the fan 175 issues from the lefthand end of the space heater 100 as viewed in FIGS. l and 3, and specifically from the lefthand end of the outer casing 120 and is directed by the user into the area where the heat is desired.

Describing now in detail the construction of the space heater 100, the fuel tank 101 has a cylindrical outer Wall 102 closed at the lefthand end thereof by an outer partspherical head 103 and having an inner part-spherical head 104 disposed inwardly from the other end thereof, the cylindrical wall 102 together with the heads 103 and 104 defining a fuel containing compartment therebetween. A filling pipe 105 for the fuel compartment is provided, the filling pipe 105 being fitted with the cap 106 in the usual manner; there also is provided in the bottom of the outer wall 102 a drain plug 107 communicating with the fuel compartment. The righthand end of the cylindrical wall 102 as viewed in FIG. 1 comprises a machinery cornpartment having a vertically arranged compartment wall 108 therein (see FIG. 2 also), and having a compartment head 109 on the outer end thereof, whereby the machinery compartment is defined by the cylindrical wall 102 and the heads 103l and 109.

In order to provide for portability of the space heater 100, the fuel tank 101 is mounted upon the pair of wheels 110 that are in turn supported upon an axle 111 (see FIG. 2), the axle 111 being mounted on the underside of the fuel tank 101 by means of a generally U-shaped bracket 112. The other end of the fuel tank 101 carries thereunder the skid 115, whereby the wheels 110 and the skid 115 are useful to support the fuel tank 101 and all other parts of the space heater 100 upon a suitable underlying support surface.

Mounted upon the top of the fuel tank 101 is an outer casing 120 also cylindrical in shape and having a diameter slightly less than that of the fuel tank 101 but having a length slightly greater than that of the cylindrical wall 102, the outer casing 120 being held in the operative position upon the fuel tank 101 by means of a pair of mounting brackets 121, (see FIG. 2 also). The righthand end of the casing 120 is provided with an outwardly directed flange 122 that is spaced a short distance to the right with respect to the righthand end of the cylindrical wall 102, the other end of the casing 120 extending to the left well beyond the lefthand end of the cylindrical wall 102 as viewed in FIG. 1. The lefthand end of the outer casing 120 carries a part-conical nose cone 123 which converges inwardly to the left but has a substantial opening therein for passage of heated air and combustion products therethrough. Mounted in the side of the casing 120 substantially centrally thereof is a door 124 that provides access to a nozzle structure and ignition system to be more fully described hereinafter, and the lefthand end of the outer casing 120 carries a partcylindrical shield 125 that is mounted on and spaced from the casing 120 by means of three angle irons 126 (see FIG. 2 also), the shield 125 therefore being cooled by air passing through the area between the outer surface of the casing 120 and the inner surface of the shield 125, a handle 127 for the space heater 100 being attached to the shield 125 so that the handle 127 is maintained at a temperature that is comfortable to the touch of a user.

Mounted within the outer casing 120 is an inner casing 130 (see FIGS. 3 and 4 also), the inner casing 130 also being generally cylindrical in shape and arranged generally concentric with the outer casing 120 but disposed to the lefthand end thereof and spaced therefrom by a plurality of angle irons 131, four of the angle irons 131 being illustrated in FIG. 4 of the drawings. The space between the outer surface of the inner casing 130 and the inner surface of the outer casing provides a cooling channel for heat exchange purposes, the area being divided into four separate channels by the angle irons 131, the channels being generally designated by the numeral 135.

The righthand end of the inner casing carries a first baille structure that is positioned within the righthand end of the inner casing 130 and is held in the proper position by a pair of annular indentations 132 extending therearound. The baille structure 140 includes a base plate 141 which is generally annular in shape and is disposed between the two indentations 132 in the periphery of the inner casing 130 and is held therein, the base plate 141 having a central opening 142 therethrough having the center thereof in alignment with the longitudinal axis of the inner casing 130. Mounted on the base plate 142 are four vanes or iins 143 which are shaped to direct air impinging upon the periphery of the base plate 141 inwardly and through the opening 142 and to impart a swirling motion thereto so as to create a vortex of air about the longitudinal axis of the inner casing 130 immediately to the left of the base plate 141 as viewed in FIG. 3. Mounted on the vanes 143 is a front plate 144 having an outer diameter slightly less than the outer diameter of the base plate 141 but arranged concentric therewith and disposed to the right thereof as Viewed in FIG. 3. Formed centrally of the front plate 144 is a central opening 145 concentric with the opening 142 in the base plate 141, the diameter of the opening 145 being substantially less than the diameter of the opening 142, whereby the inner edge 146 of the lfront plate 144 overlies the periphery of the central opening 142 in the base plate 141. There further are provided around the periphery of the front plate 144 and equiangu'larly spaced therearound four semi-circular cutouts 147 disposed between adjacent pairs of the varies 143 and arranged to pass air therethrough and against the front surface of the base plate 141 and against the adjacent surface of the associated vane 143, thereby to direct air into a swirling stream exiting from the baille structure through the cenral opening 142 in the base plate 141. Preferably the cutouts 147 are arcs of a circle having a radius equal to the radius of the central opening 145 in the front plate 144. In this connection it will be noted that the cutout portions 147 are disposed immediately adjacent to the vane 143 disposed in a counterclockwise direction with respect thereto as viewed in FIG. 4.

In accordance with the present invention, there is mounted on the front plate 144 a valveplate 150 that cooperates with the baille structure 140; more specifically, as will `be described ymore fully hereinafter, a stream of air is produced traveling down the outer casing 120 from right to left as viewed in FIGS. l and 3, the baille structure 140 and the associated valve plate 150 serving to divide the air stream into two portions; a ilrst portion of the air stream is directed through the cutouts 147 and into the central opening 142 in the base plate 141 for the combustion purposes, and the second portion of the air stream is directed into the channels 135 to cool the inner casing 130 and to pick up heat therefrom, thus to achieve the heat exchange function. To this end the valve plate 150 is generally circular in shape and has a diameter substantially equal to the diameter of the front plate 144 and also has a central opening 151 therein that is substantially greater than the diameter of the central openings 142 and 145, but concentric therewith. Disposed about the periphery of the valve plate 152 and arranged equiangularly therearound are four cutouts 152 providing openings through the valve plate 150, the cutouts preferably being semi-circular and having the same shape and size as the cutouts 147 in the front plate 144. The valve plate 152 further has a pair of angular Slots 153 therein that extend along arcs having radii with centers at the longitudinal axis of the inner casing 130 each receiving therethrough a `bolt 154 engaging a threaded opening in the front plate 144, the slots 153 and the bolts 154 permitting limited angular adjustment between the openings 147 and 152, whereby to permit adjustment of the amount of air diverted into the first portion of the air stream flowing through the openings 152 and 147 and against the vanes 143 and then through the opening 142.

The inner casing 130 serves to provide a combustion chamber for the burning of fuel therein, thereby to heat the air passing through the casing 130 and through the channels 135, thus to provide the heating function of the space heater 100. To this end a fuel system is provided for the space heater including a fuel nozzle 160 mounted upon the front plate 144 -by means of bracket structure 151 and cooperating screws .162, the nozzle 160 being arranged to inject fuel in a direction longitudinally of the inner casing 130 and along the longitudinal axis thereof. The fuel for burning in the space heater 100 is contained within the fuel tank 101 as described above and is removed therefrom fby means of a fuel pump 165, the fuel pump 165 having an inlet 166 connected by copper tubing 163 to a fuel filter 164 mounted within the machinery compartment and connected in turn to the interior of the fuel tank 101 by a tubing 168. The fuel pump 165 has an outlet port 167 connected by a tubing 169 to the nozzle 160, whereby upon operation of the fuel pump 165, fuel is pumped from the tank 101 through the tubing 168, the iilter 164 and the tubing 163 to the inlet port 166, and from the outlet port 167 through the tubing 169 to the nozzle 160.

In order to provide motive power for running the pump 165, a drive motor 170 has been provided, the drive motor 170 being mounted within the righthand end of the outer casing 120 by means of a mounting bracket 171; more particularly the drive motor 170 is mounted essentially centrally of the outer casing 12()` and having the longitudinal axis thereof in alignment with the longitudinal axis of the pump 165, there being a substantial annular passage around both the pump 165 and the drive motor 170 within the outer casing 120, the pump 165 being actually mounted on and coupled to the drive motor 170. As illustrated, the drive motor 170 is an electrical motor that may be powered from a volt, 60 cycle, a.c. line, and in a typical illustrative example of the space heater 100 is a 1A horsepower motor. In order to provide the necessary electrical power Afor the motor 170, a suitable electrical plug 172 is provided adapted to be connected to a source of electrical power and connecting to a pair of conductors 173 connected to the input terminals of the drive motor 170. The drive motor 170 also has an output shaft 174 that carries thereon a fan 175, the shaft 174 and the fan 175 rotating about an axis that is concentric with the axes of the casings and 130, the fan 175 substantially filling the interior of the outer casing 120 so as to create a strong stream of air flowing along the outer casing 120 from right to left as viewed in FIGS. l and 3. More specifically, the fan 175 serves to draw air across the pump 165 and into the righthand end of the casing 120 and around` the drive motor 170, thereby to cool both the pump and the drive motor and to set in motion within the casing 120 a strong stream of air flowing therealong and to the left and toward the adjacent end of the inner casing 130. As has been explained above, the first baiiie structure 140 and the valve plate 150 therein divide the air stream from the fan into two portions, the first portion being directed inwardly through the openings 152 and 147 against the vanes 143 and thus in a swirling motion through the central opening 142 and about the outer end of the fuel nozzle 160, the air being swirled into a Vortex about the outer end of the nozzle 160.

In order to ignite the resultant fuel-air mixture within the inner casing 130 resulting from the operation of the fuel pump 165 and the air fan 175, an ignition system has been provided. More specifically, there is dis-l posed within the machinery compartment of the fuel tank 101 a high voltage transformer 181 which can produce an output voltage of ten thousand volts or more. The pirinary winding of the transformer 181 is connected to the input conductors 173 and the secondary winding of the transformer 181 is connected to a pair of conductors 182 which extend to a pair of electrodes 185 mounted adjacent to the fuel nozzle 160 and having the outer ends thereof spaced a short distance away from the opening at the outer end of the fuel nozzle 160. More specifically, the electrodes are mounted on a pair of associated insulators 183 by means of a bracket 184 upon the nozzle 160, the electrodes 185 being electrically insulated from the nozzle 160 although mounted thereon. The high voltage from the transformer 181 when applied to the electrodes 185 causes `a continual discharge or arc therebetween, this are serving to ignite the fuel-air mixture within the inner casing 130, thus to insure continual burning thereof within the casing 130 so long as the fuel pump 165, the fan 175 and the electrodes 185 are all properly functioning. The door 124 in the outer casing 130 permits ready tccess to the nozzle 160 and the electrodes 185 as well as the valve plate 150 for service and adjustment thereof.

As a result of the above described structure, it will be appreciated that the fuel in the fuel tank 101 is pumped to the nozzle 160 and upon ejection therefrom is mixed with a swirling vortex of air that is created by the fan 175 and the cooperating baffle structure 140 and the valve plate 150. The proper amount of air for the desired type of combustion of the fuel can be obtained by adjusting the valve plate 150 with respect to the front plate 144, thereby to increase or decrease the amount of air passing through the openings 142 and 147 and thus against the vanes 143 and through the opening 142 of the base plate 141. The valve plate 150 more particularly is adjusted in accordance with the elevation above sea level of the space heater 100 during use and to adjust for changes in the weather, all of which vary the available oxygen supply and thus require adjustment of the air to fuel ratio.

The baiiie structure 140 and particularly the vanes 143 thereon cause the air fed past the nozzle 160 to be in violent swirling motion similar to a cyclone or tornado, whereby to tend to confine the combustion zone of the fuel-air mixture centrally and along the axis of the inner casing 130, thus to minimize corrosion of the interior of the casing 130. Likewise the air passing along the outer surface of the inner casing 130 through the passages 135 tends to cool `the inner casing 130 thus to inhibit and lower the rate of corrosion of the inner `Case ing 130, all while achieving the desired heat exchange function with respect to the second portion of the air stream;

It further is desirable to limit the longitudinal extent of the combustion zone within the inner casing 130, and specifically positively to prevent the emergence of flames or highly heated gases directly from the exit end of the inner casing 130, ie., the lefthan-d end as viewed in FIGS. 1 and 3. To this end a second batile structure 190l has been provided at the exit end of the inner casing 130. The baffle structure more specifically includes a baffle ring 191 extending around the inner periphery of the inner casing 130 at the lefthand or exit end thereof, the ring 191 having a plurality of bifurcated mountings lor fingers 192 about the periphery thereof that extend out beyond the associated end of the casing 130` and then radially outwardly to engage against the inner surface of the outer casing 120. It will be appreciated that the bafe ring 191 will tend to direct air and combustion products that are moving along the inner surface of the inner casing 130 inwardly and then through an opening 193 centrally thereof and concentric with the axis of the inner casing 130. Mounted concentric with the opening 193 but spaced a short distance therefrom is a dish-shaped baille member 195 which is supported by a plurality of legs 196 that extend outwardly therefrom and toward the baille ring 191 and terminate in mounting ilanges 197 extending between an adjacent pair of ilngers 192 and secured to the baille ring 191 by means of bolts 198. The baille member has a general circular outline having a diameterslightly greater that that of the opening 193 and also having a concave surface 199 disposed toward the adjacent end of the outer casing 130' and having the outer edge of the surface 199 overlying the periphery of the opening 193. Air and combustion products being swept along the inner casing 130 are first directed inwardly and through the opening 193 by means of the baille ring 191 and are thus directed against the concave surface 199 on the baille member 195 and are then directed back into the adjacent end of the inner casing 130 as well as around the outer edge of the baille member 195. The cooperation of the bafe ring 191 and the baille member 195 produces in effect a build up of static pressure at the exit end of the casing 130, the static pressure aiding in holding the combustion zone toward the righthand end of the casing 130, and also insuring burning of all the fuel within the casing 130, and also thus positively to prevent the emergence of llames from the exit end of the space heater 100.

The nose cone 123 also cooperates with the baille member 195, and more particularly, the second stream of air that passes through the channels 135 is `directed by the converging inner surface of the nose cone 123 toward the baille member 195, thus to cool the baille member 195 and to permit the continual operation thereof as a `deilector for the hot combustion products being carried by the iirst portion of air stream issuing from the combustion chamber. The nose cone 123 further tends to conilne the heated air stream issuing from the space heater 100 into a relatively narrow conilguration, whereby the output yof the space heater 100 can be directed to the place where the heat is needed by the user thereof.

A further adjustment of the buildup of static or back pressure at the exit end of the casing 130 is accomplished by adjusting the outlet end or the lefthand end of the inner casing 130 (as viewed in FIGS. l and 3) with respect to the outer casing 120, whereby to adjust the size of the opening between the periphery of the baille member 195 and the nose cone 123. To this end, the outer casing 120 has an elongated longitudinally extending slot 128 in the lower portion thereof adjacent to the front end thereof and receives therethrough an adjusting screw 155 which extends through the slot 128 and into a complementarily threaded opening the lower portion of the inner casing 130. By means of the screw 155, the posi tion of the inner casing 130 longitudinally along the outer casing 120 can be adjusted within the limits of the slot 128, a typically total adjustment for example being 1/2 inch. By moving the inner casing 130 to the left until the screw 155 is in the lefthand end of the slot 128 as viewed in FIG. 3, the area of the passage between the baille member 195 and the nose cone 123 is decreased, thereby to increase the buildup of static pressure at the outlet of the inner casing 130, and thus more positively to restrict the Vcombustion zone within the inner casing 131). Conversely, by moving the inner casing 130 until the screw 155 is in the righthand end of the slot 128, the area of the passage between the baille `member 195 and the nose cone 123 is increased. As a consequence, the static pressure is reduced, thereby permitting an enlargement of the combustion zone within the inner casing 13). Such adjustment of the parts to vary the back pressure is highly useful in the case of employment of the heater 100 at extremely high elevations r at extremely low elevations. It will be understood that tightening of the screw 15S holds the inner casing 130 in the adjusted position with respect to the outer casing 120, and thus holds the baille member 195 in the adjusted position with respect to the nose cone 123. It further is noted that such adjustment of the back pressure provides a completely new range of adjustment and a completely new range of effects that can be obtained by moving and positioning the valve plate 150.

Recapitulating now the method of operation of the space heater 101i, the electrical plug 172 is inserted into a suitable receptacle, thereby to apply the operating potentials to the drive motor 176i and to the electrodes 185 via tl e transformer 181. The fuel tank 101 will contain a quantity of fuel inserted thereinto through the fuel pipe 105, a suitable fuel being kerosene or No. 1 home heating fuel oil. As soon as the drive motor 170 is energized, the fuel pump 165 will be placed in operation to draw fuel from the fuel tank 101 through the filter 164 and to discharge it through the outlet line 169 to the nozzle 160, the nozzle 169 serving to spray the fuel into the combustion chamber within the inner casing 130. Operation of the drive motor 176 also operates the fan 175, thereby to create a strong draft or stream of air ilowing from right to left as viewed in FIGS. l and 3. The air stream is divided into a first portion that passes through the aligned portions of the openings 152 in the valve plate 150 and the openings 147 in the front plate 144 and is directed by the vanes 143 into a swirling air mass that passes through the central opening 142 in the base plate 141 and thus around the exit end of the nozzle 160; a second stream of air is directed by the baille structure into the passages 135 between the outer casing 120 and the inner casing 130.

The iirst stream of air mixes with the fuel from the nozzle and passes through the arc between the electrodes 185, thereby to be ignited and to burn in a combustion zone within the inner casing 131B. If the space heater 160 smokes or otherwise gives evidence of insuillcient air in the combustion zone, the access door 124 is opened and the bolts 154 are loosened and the valve plate 151) rotated in a counterclockwise direction as viewed in FIG. 4 thereby to place in alignment greater portions of the openings 152 and 147, thus to divert more air into the inner casing 130 through the baille structure 140. Conversely, if too much air is being admitted, the bolts 154 can be loosened and the valve plate 150 rotated in a clockwise direction thus to provide for a smaller overlap of the openings 152 and 147, thus to decrease the amount of air admitted into the iirst air stream entering the inner casing 130.

The burning fuel-air mixture within the inner casing 130 is confined in an area well spaced from the ends of the inner casing 13) and from the side walls thereof. More speciilcally, the strong stream of air from the fan 175 tends to insure that the combustion zone is spaced well into the inner casing 130 and does not extend outwardly therefrom to the right as viewed in FIGS. 1 and 3. The swirling motion of the first stream of air entering the casing 130 tends to confine the combustion zones along the axis of the inner casing 130 and away from the side walls thereof. Finally, the outer baille structure 190 deilects at least a portion of the air stream and the combustion products carried thereby issuing from the inner casing 1361 back thereinto and builds up a static pressure at the outer end thereof, i.e., the end disposed to the left in FIGS. l and 3, and thereby conilnes the combustion zone within the inner casing 130 and toward the righthand end thereof as viewed in FIGS. l and 3, and also thus positively to prevent the emergence of ilames from the exit end of the inner casing .130.

Simultaneously the second portion of the air stream ilows through the passages 135 and serves to cool the outer surface to the inner casing 130, it also being pointed out that the full air stream serves to cool both the pump and the drive motor thus to preheat the air prior to admission to the inner casing 136 and the passages 135. The second portion of the air stream in the passages 135 is accordingly heated and passes therethrough from right to left as viewed in FIGS. 1 and 3 and finally is deflected by the converging inner surface of the nose cone 123 toward the baille member 195, thus to cool the baille member 195 and to provide for a mixing of the first and second air streams and the combustion products carried by the first air stream, thus to provide a substantially homogeneous heated gas stream issuing from the space heater 100 to be utilized for the space heating function.

In a typical constructional example of the space heater 100, the overall length thereof is 36 inches, the overall Width thereof is inches and the overall height thereof is 24 inches. The outer casing 120 has an overall length of inches and a diameter of 91/2 inches; the inner casing 130 has an overall length of 13 inches and a diameter of 7 inches; the opening 142 has a diameter of 31A inches, the opening 146 has a diameter of 21A: inches, and the openings 147 and 152 have a radius curvature of 11/8 inches; the opening 193 in the baille ring 191 has a diameter of 4% inches, the outer diameter of the baille member 195 is 41/2 inches and the inner surface of the baille member 195 is spaced from the outer end of the inner casing 130 a distance of As inch. The motor .170 is a 1A; horsepower motor and the fan delivers approximately 900 cubic feet of air per minute and the nozzle 160 delivers approximately 0.75 gallon of fuel per hour, whereby to provide a heat capacity of 100,000 B.t.u. per hour for the space heater 100.

From the above it will be seen that there has been provided a space heater which fulfills all of the objects and advantages set forth above. More specifically, an improved baille structure 140 having a cooperating valve plate 150 has been provided which permits ready adjustment of the portion of the total air stream directed into the combustion zone thereby to regulate the fuel-air mixture. The second baille structure 190 has also been provided which directs the combustion gases back into the casing 130 thus to create a back pressure which confines the combustion zone within the inner casing 130, and thus alsopositively to prevent the emergence of llames from the exit ends of the casings 120 and 130.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is: I

1. A space heater comprising a generally cylindrical casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said casing adjacent to one end thereof, means for pumping fuel from a source thereof to :said nozzle to inject a stream of fuel into said one end of said casing generally along the longitudinal axis thereof, a fan for creating a stream of air into said one end of said casing in a direction substantially parallel to the longitudinal axis thereof and around said nozzle, a baille structure mounted within and adjacent to said one end of said casing and dividing said air stream into a iirst portion directed inwardly and around said nozzle and a second portion directed along the outer surface of said casing, an ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel from said nozzle and the air in said ilrst portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein, and a valve plate cooperating with said baille structure and adjustable with respect thereto for adjusting the proportion between Said first and second portions of said air stream.

2. The space heater set forth in claim 1, wherein, said baille structure comprises a plate disposed in said one end of said casing and having an opening centrally therein to receive said nozzle therethrough and a plurality of openings around the periphery for receiving the first portion of the air stream therethrough.

3. The space heater set forth in claim 1, wherein, said valve plate is mounted upon said baille structure and is adjustably mounted with respect thereto.

4. The space heater set forth in claim 1, and further comprising a plurality of fins mounted in said baille structure and directing said iirst portion of the air stream inwardly toward said nozzle and imparting a swirling motion to said first portion of the air stream.

5. The spacer heater set forth in claim 1, and further comprising means mounting said nozzle on said baille structure.

6. A space heater comprising a generally cylindrical outer casing, a generally cylindrical inner casing disposed within said outer casing and spaced therefrom to define a longitudinally extending channel therebetween, said inner casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said inner casing adjacent to one end thereof, means for pumping fuel from a source thereof to said nozzle to inject a stream of fuel into said combustion chamber through said one end of said inner casing generally along the longitudinal axis thereof, a fan for creating a stream of air directed along said outer casing toward said one end of said inner casing in a direction substantially parallel to the longitudinal axes of said casings, a baille structure mounted within and adjacent to said one end of said inner casing and dividing said air stream into a first portion directed inwardly into said inner casing and around said nozzle and a second portion directed outwardly into said channel and along the facing surfaces of said casings, an ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel from said nozzle and the air in the iirst portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein, the second portion of said air stream serving to cool the outer surface of said inner casing and said combustion chamber, and `a valve plate cooperating with said baille structure and adjustable with respect thereto for adjusting the proportion between said lli-st and second portions of said air stream.

7. The space heater set forth in claim 6, wherein, said bafile structure includes a plurality of fins imparting a swirling motion to said ilrst portion of the air stream to confine said combustion zone to an area spaced inwardly with respect to the inner surface of said inner casing.

8. The space heater set forth in claim 6, wherein, said baille structure comprises a plate disposed in one end of said casing and having an opening centrally therein to receive said nozzle therethrough and a plurality of openings around the periphery for receiving the first portion of the air stream therethrough.

9. The space heater set Iforth in claim 6, and further comprising means mounting said nozzle on said baille structure.

10. A space heater comprising a generally cylindrical outer casing, a generally cylindrical inner casing disposed within said outer casing and spaced therefrom to define a longitudinally extending channel therebetween, said inner casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said inner casing adjacent to one end thereof, means for pumping fuel `from a source thereof to said nozzle to inject a stream of fuel into said combustion chamber through one end of said inner casing generally along the longitudinal axis thereof, a fan for creating a stream `of air directed along said outer casing toward said one end of said inner casing in a direction substantially parallel to the longitudinal axes of said casings, a first baille structure mounted within and adjacent to said one end of said inner casing and dividing said air stream into a ilrst portion directed inwardly into said inner casing and around said nozzle and a second portion directed outwardly into said channel and along the facing surfaces of said casings, an ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel from said nozzle and the air in the first portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein, the second portion of said air stream serving to cool the outer surface of said inner casing and said combustion chamber, a valve plate cooperating with said baflie structure and adjustable with respect thereto for adjusting the proportion between said first and second portions of said air stream, and a second batile structure mounted ad jacent to the other end of said inner casing and directing said first portion of the air stream and the combustion products carried thereby back toward said one end of said casing to confine the combustion zone of the burning fuelair mixture toward said one end of said inner casing and positively to prevent the escape of flame from the other end of said casings.

11. A space heater comprising, a generally cylindrical outer casing, a generally cylindrical inner casing disposed within said outer casing adjacent to one end thereof and spaced therefrom to define a longitudinally extending channel therebetween, said inner casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said inner casing adjacent to the one end thereof disposed toward the other end of said outer casing, a fuel pump mounted adjacent to said other end of said outer casing for pumping fuel to said nozzle to inject a stream of fuel into said combustion chamber through said one end of said inner casing generally along the longitudinal axis thereof, a motor mounted in said outer casing between said fuel pump and the adjacent end of said inner casing and operatively coupled to said fuel pump, a fan mounted in said outer casing between said motor and the adjacent end of said inner casing and operatively coupled to said motor, the driving of said fan by said motor drawing a stream of air over both said fuel pump and said motor and along said outer casing toward said one end of said inner casing in a direction substantially parallel to the longitudinal axes of said casings, a baffle structure mounted within and adjacent to said one end of said inner casing and dividing said air stream into a first portion directed inwardly into said inner casing and around said nozzle and a second portion directed outwardly into said channels and along the facing surfaces of said casings, an ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel from said nozzle and the air in the first portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein, the second portion of said air stream serving to cool the outer surface of said inner casing and said combustion chamber, a valve plate cooperating with said baflie structure and adjustable with respect thereto for adjusting the proportion between said first and second portions of said air stream, and a second bafiie structure mounted adjacent to the other end of said inner casing and directing said first portion of the air stream and the combustion products carried thereby back toward said one end of said casing to confine the combustion zone of the burning fuel-air mixture toward said one end of said inner casing and positively to prevent escape of flame from the other end of said casmgs.

12. A space heater comprising a generally cylindrical outer casing, a generally cylindrical inner casing disposed within said outer casing and spaced therefrom to define a longitudinally extending channel therebetween, said inner casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said inner casing adjacent to one end thereof, means for pumping fuel from a source thereof to said nozzle to inject a stream of fuel into said combustion chamber through one end of said inner casing generally along the longitudinal axis thereof, a fan for creating a stream of air directed along said outer casing toward said one end of said inner casing in a direction substantially parallel to the longitudinal axes of said casings, a rst baffle structure mounted adjacent to said one end of said inner casing and dividing said air stream into a first portion directed inwardly into said inner casing and around said nozzle and a second portion directed outwardly into said channel and along the facing surface of said casings, said first baffle structure being adjustable for adjusting the proportion between said first and second portions of said air stream, an ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel from said nozzle and the air in the first portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein, the second portion of said air stream serving to cool the outer surface of said inner casing and said combustion chamber, a second batiie structure mounted adjacent to the other end of said inner casing and directing said first portion of the air stream and the combustion products carried thereby back toward said one end of said casing to confine the combustion zone of the burning fuel-air mixture toward said one end of said inner casing and positively to prevent escape of flame from the other end of said casings, an inwardly converging nose cone mounted adjacent to the outer end of the outer casing and surrounding said second baffle structure to provide an outlet passage therebetween, and structure for adjusting the position between said second baffle structure and said nose cone to change the area `of the passage therebetween and thus to adjust the back pressure on the air stream and combustion products from said casings.

13. The space heater set forth in claim 12, wherein said second bafiie structure is mounted on said inner casing, said nose cone is mounted on said outer casing, and said adjusting structure adjusts the position between said inner casing and outer casing, thus to adjust the position between said second baflie structure and said nose cone to adjust the area of the passage therebetween.

14. The space heater set forth in claim 12, wherein, the said first baffle structure is located within said inner casing.

15. A space heater comprising a generally cylindrical casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said casing adjacent to one end thereof, means for pumping fuel from a source thereof to said nozzle to inject a stream of fuel into said lone end of said casing generally along the longitudinal axis thereof, a fan for creating a stream of air into said one end of said casing in a direction substantially parallel to the longitudinal axis thereof and around said nozzle, a first bafiie structure mounted within and adjacent to said one end of said casing and dividing said air stream into a first portion directed inwardly and around said nozzle and a second portion directed along the outer surface of said casing, and ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel from said nozzle and the air in said first portion of the air stream to cause combustion o-f said fuel within said combustion chamber in a combustion zone therein, a valve plate cooperating with said baffle structure and adjustable with respect thereto for adjusting the proportion between said first and second portions of said air stream, and a second bafiie structure mounted adjacent to the other end of said casing and directing said first portion of the air stream and the combustion products carried thereby back toward said one end of said casing to confine the combustion zone of the burning fuel-air mixture toward said one end of said casing and positively to prevent the escape of flame from said other end of said casing.

16. The space heater set forth in claim 15, wherein, said second batile structure includes a baffle ring disposed adjacent to said other end of said casing and extending radially inwardly from the inner surface thereof, and a baffle member spaced from said other end of said casing and in longitudinal alignment with the opening in said bafe ring and overlying the edges thereof.

17. The space heater set forth in claim 16, wherein, said bafiie member is generally dish-shaped and has the concave side thereof disposed toward said other end of said casing.

18. A space heater comprising a generally cylindrical outer casing, a generally cylindrical inner casing disposed within said outer casing and spaced therefrom to define a longitudinally extending channel therebetween, said inner casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said inner casing adjacent to one end thereof, means for pumping fuel from a source thereof to said nozzle to inject a stream yof fuel into said combustion chamber through one end of said inner casing generally along the longitudinal axis thereof, a fan for creating a stream of air directed along said outer casing toward said one end of said inner casing in a direction substantially parallel to the longitudinal axes of said casings, a first bafiie structure mounted within and adjacent to said lone end of said inner casing and dividing said air stream into a first portion -directed inwardly into said inner casing and around said nozzle and a second portion directed outwardly into said channel and along the facing surfaces of said casings, an ignition system for igniting the fuelair mixture resulting from the mixing lof the fuel from said nozzle and the air in the first portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein, the second portion of said air stream serving to cool the outer surface of said inner casing and said combustion chamber, a valve plate cooperating with said bafiie structure and adjustable with respect thereto for adjusting the proportion between said rst and second portion of said air stream,` and a second baffle structure mounted adjacent to the other end of said inner casing and directing said first portion of the air stream and the combustion products carried thereby back toward said one end of said casing to confine the combustion zone of the burning fuel-air mixture toward said Xone end of said inner casing and positively to prevent escape of flame from the other end of said casings.

19. The space heater set forth in claim 18, and further comprising, a nose cone mounted adjacent to the other end of said outer casing, and directing said second portion -of the air stream inwardly and around said second bafiie structure to cool the same.

20. A space heater comprising, a generally cylindrical outer casing, a generally cylindrical inner casing disposed within said outer casing adjacent to one end thereof and spaced therefrom to define a longitudinally extending channel therebetween, said inner casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said inner casing adjacent to the one end thereof disposed toward the other end of said outer casing, a fuel pump mounted adjacent to said other end of said outer casing for pumping fuel to said nozzle to inject a stream of fuel into said combustion chamber through said one end of said inner casing generally along the longitudinal axis thereof, a motor mounted in said outer casing between said fuel pump and the adjacent end of said inner casing and operatively coupled to said fuel pump, a fan mounted in said outer casing between said motor and the adjacent end of said inner casing and operatively coupled to said motor, the driving of said fan by said motor drawing a stream of air over both said fuel pump and said motor and along said youter casing toward said one end of said inner casing in a direction substantially parallel to the longitudinal axes of said casings, a bafiie structure mounted within and adjacent to said one end of said inner casing and dividing said air stream into a first portion directed inwardly into said inner casing and around said nozzle and a second portion directed outwardly into said channels and along the facing surfaces of said casings, an ignition system for igniting the fuel-air mixture resulting from the mixing of the fuel from said nozzle and the air in the first portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein, the second portion of said air stream serving to cool the outer surface of said inner casing and said combustion chamber, and a valve plate cooperating with said baffle structure and adjustable with respect thereto for adjusting the proportion between said first and second portions of said air stream.

21. A space heater comprising a generally cylindrical casing defining therein a fuel combustion chamber, a fuel nozzle mounted substantially on the longitudinal axis of said casing adjacent to one end thereof, means for pumping fuel from a source thereof to said nozzle to inject a stream of fuel into said one end of said casing generally along `the longitudinal axis thereof, a fan for creating a stream of air into said one end of said casing in a direction substantially parallel to the longitudinal axis thereof and around said nozzle, a. baflie structure mounted within and adjacent to said one end of said casing and dividing said air stream into a first portion directed inwardly and around said nozzle and a second portion directed along the outer surface of said casing, said baffle structure being adjustable for adjusting the proportion between said first and second portions of said air stream, and an ignition system for igniting the fuelair mixture resulting from the mixing of the fuel from said nozzle and the air in said first portion of the air stream to cause combustion of said fuel within said combustion chamber in a combustion zone therein.

22. The space heater set forth in claim 21, and further comprising a plurality of fins mounted in said baie structure and directing said first portion yof the air stream inwardly toward said nozzle and imparting a swirling motion to said first portion of the air stream.

References Cited UNITED STATES PATENTS 2,866,627 12/1958 Sherman.

3,101,193 8/1963 VarVel.

3,211,439 10/1965 Fahlberg.

3,256,003 6/1966 Briggs.

3,263,978 8/1966 Safford.

3,301,308 1/1967 Briggs.

3,319,947 5/1967 Truesdell.

JOHN J. CAMBY, Acting Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,393,903 July 23, 1968 Carl A. Berglund, Jr.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line lz "151" should read 161 Column 6,

line 6, "pirmary" should read primary line Z4, "tccess" should read access Column 7, line 52, after "opening" insert in Column 8, line 71, "to" should read of Column 13, line 36, "portion" should read portions Signed and sealed this 16th day of December 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents WILLIAM E. SCHUYLER, IR.

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