US2477473A - Electrical space heater - Google Patents

Description

July 26, 1949. K. e. ANDERSON 2,477,473

ELECTRICAL SPACE HEATER Filed Jan. 51, 1947 2 Sheets-Sheet 1 1 Inn v III'IIII,

j; INVENTOR.

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July 26, 1949.

Filed Jan. 31, 1947 K. G. ANDERSON ELECTRICAL SPACE HEATER 2 Sheets-Sheet 2 INVENTOR.

- 1524507 azye @za e/flm J e d v dud/wow Patented July 26, 1949 UNITED STATES PATENT OFFICE ELECTRICAL SPACE HEATER Kador George Anderson, Chicago, 111.

Application January 31, 1947, Serial No. 725,697

8 Claims.

1 The present invention relates to space heaters and in particular to improvements in the construction of space heaters which use an electrical resistance unit as the source of heat.

Conventional electric space heaters may be divided into two classes; radiant heaters which depend upon the direct radiation of heat generated by an electrical resistance, and circulating or convection heaters. Circulating heaters are usually provided with a fan which moves the air rapidly over a heated element thus warming the air in the room by forced convection. Radiant heaters cause the surface of the body exposed to the glowing element to become excessively warm but heat is not transmitted to surfaces which are not exposed to the direct heat rays from the element. Electrical space heaters of the forced convection types are generally a source of discomfort to the occupants of a room in which such a heater is operated. Large quantities of air are moved past the heating element by means of the circulating fan, and this causes drafts in the room which may impair the health of small children and cause discomfort to other occupants of the room. Moreover,;

ers of all types is the lack of humidifying means.

The low humidity in an electrically heated room causes discomfort to the occupants and also damages the furnishings by drying them to the point that the wood and glue check and crack.

Humidifiers of various types have been tried on;

electrical heaters but they have either been ex- .pensive or have resulted in excessive corrosion on the heating element.

The object of the present invention, therefore,

is to provide a space heater which overcomes.

the objections of the prior art structures. As will hereinafter appear this object is accomplished by the provision of an improved circulating heater which will operate to heat and circulate the air in a room without requiring the use of a fan or other mechanical circulating device. Another object of the invention is to provide a. space heater of the class described which will heat a relatively small volume of air to a high temperature, humidify the heated air, and i then difiuse this heated and humidified air throughout the room in such a manner that annoying drafts will be substantially eliminated. These and other objects and advantages of the invention will be made apparent in the accomvwhich fits within the shell l5.

panying drawings and the following description of one preferred embodiment thereof.

In the drawings,

Fig. 1 is a perspective view of a space heater of the class described embodying the features of the present invention;

Fig. 2 is a sectional view taken on line 2-2 in Fig.

Fig. 3 is a fragmentary sectional view taken on line 33 in Fig. 1; and

Fig. 4 is a fragmentary sectional view taken on line 4-4 in Fig. 1.

The improved heating and circulating effect attained from a space heater embodyin the features of the present invention is believed to be due to the fact that the air is heated in a substantially enclosed chamber. The radiant heat from an electrical element is restricted to this confined area and does not pass to the surrounding atmosphere. The air is heated to a relatively high temperature in the enclosed space and this increases the convection effect when the heated air is vented. The high velocity of this vented air stream is utilized to draw humidified air into the heated air stream. The improved space heater as illustrated comprises a cabinet 5, a heating chamber 7 within the cabinet, an electrical resistance unit 9, disposed within the heating chamber 1, openings in the cabinet for admitting cold air to the heating chamber, a chimney I l, for venting the heated air from the heating chamber 1, and for confining the stream of vented air, means for drawing humidified air into said heated air stream, and a diifuser i3 for distributing the heated and humidified air throughout the room.

is either formed with reinforcing type lock joints or comprises sheets bolted or riveted to a frame. A hinged door I1 is provided in one side of the cabinet 5 to allow access to the humidifying means. The cabinet structure includes a top closure l9 which is shaped as illustrated and The top It! is held in position by spring clips 2! in order that it may be easily removed. The cold air inlet openings are provided by louvers or ports 23 disposed around the lower section of the cabinet shell IS. A second set of louvers or ports 25, which allow the circulation of air through the humidifier, are vertically spaced from the air intake louvers 23.

The bottom closure of the cabinet 5 is a generally square sheet metal member 21. Symmetrically disposed portions are pressed out of the bottom surface of the closures to provide four legs 29 which support the cabinet 5. Conveniently the bottom closure is attached to the shell 15 by rolling a lock joint 3| in three sides of the bottom member 21 which may be engaged by a cooperating flange 33 on the, shell I5. The engaged members may be held in place by a thumb screw 35 as illustrated.

The bottom of the heating chamber 1 is made from a generally square, downwardly dished pan member 31 of sheet metal, which isadapted to. fit

within the cabinet 5. A plurality of turbulence rings 39 are spun or pressed into the bottom of the pan member 3'1. The turbulence rings. 39; comprise a series of alternately concave and. convex, depending concentric ridges shaped substantially as shown in the drawings. also serves as an added reinforcing member for the cabinet. I

The top of the heating chamberis formed from a square pan member 4|, similar-to pan 3-1; and

into-which are formed'a series of turbulence rings 43 corresponding to the lower rings 39. The upper pan 4i= is vertically spaced fromthe lower pan member 31, substantially as shown inthe drawings.- A heated airyent 45; adapted to connect with the chimney I I, is located in the center of'theupperpanA-L The lower surface of the bottom-pan 31 and the upper-surface of thetop pan 4 I are covered with a suitableinsulating; material 41 such asa inch sheetof asbestos orthe like. The interior surfaces of the heating-chamber are desirably blackfinishedso-as to provideefficientheat radiating surfaces; 7

Aconvenient method for assembling the pans siand is-illustrated-in detail'in-Figs. 3'and'4, Indentations-M are; made in the shell l5 at the level at which the pans areto be supported. The indentations 49w for the top. pan 41 are horizontally spaced from those providedfor the bottompansi'sothat notches-51 can be cut' in the bottom pan 37 to allow it-to slip" into position. Boltsbfi are provided'to maintain the-pans in position on the indentations.

The electricalresistance unit orelement 9 is disc-shaped and is provided-with" a seriesofvertical passageways; The resistanceunitll" is horizontallydisposed under the heated" air vent es in the upper pan 41-. Electrical leadsbiextend downwardly through'the bottom of the heating chamber- 1 where they are attached'to a frame 51 provided on the bottom member 21to' support the element: 9 The heating-element 9-may conveniently-v comprise an electrical resistance wound on an insulating bodywhich is covered-by an integrali metal shell. This enclosed construction obviates the dangerof short circuits and-shocks. Heating elements-of-this-type are used in-electric stoves, etc. and-are soldunder the tradename of/Calrod.

The chimney I lextends vertically and connects the heatedaair vent45 in the upper pan-4l with a point. adjacent: the top of the cabinet-"5, as shown inthe drawings; The upper portion of the chimney ll iszsupported by'a plurality of guide wires. 59' whichare attached atone end-to" the cabinet shell l5iandat the other end to=a collar that the heated air will not be cooled--whileitis- The bottom closure 4 passing through the chimney. A suitable mate= rial for this purpose has been found to be a .032-inch thick aluminum sheet.

The cabinet top [9 is provided with a flared opening 83 as is shown in the drawings. The lower portion of this opening 63 is adapted to fit loosely around the upper portion of the chimney H to provide an aspirating ring 65. The inverted, generally cone-shaped air difiuser I3 is supported within this flared opening by four brackets 61.

The annular air passageway 69 between the flared opening 63 and the diffusing cone l3 should be proportioned so that the total area of the passageway 69 is greater that the cross-sectional area ofthe top of the chimney H. Heated air flowing from: the chimney II will then have an unimpeded path as it passes out around the diffuser l3.

Radiating fins H are attached to the bottom pan member" 31 of the heating chamber 1, in order to increase'the' transfer of heat-to-the air. The radiating-fins Tl" are vertically disposed and extend radially outwardly from the central portion'of. the heating chamber. The innerportions of the fins H' are in close proximity with the heating element 9,- oreven may beattached to the element.

A plurality 'of flow-directing and radiatingshells F3 are supported onthe" upper surface of the heating element 9* by means ofwires as is shownin the drawings. The shells' 13* are made from sheet material" and are desirably concentric cylinders or frustums of" cones. The number'of these shells required for optimum heat transfer varies withthe sizeof thechimney and the temperature of the heatingelement; but it has been found thatthe air'passagewaysbetween the shells w-shoultl-beat least about mm; wide; Both the fins H and the shells 13- should be disposed in: directions which are generally p'arallelto the streanrfiow of the air in the heaterso as to'cause but littleinterference with" natural convection currents.

An annularhumidifier'pan 11- fabricated from sheet" material which=is a good conductor-of heat, is supported-0n the outer surface of the chimney II. The central opening!!! in the'p'a'n' 11f is adapted-to support thepan" at the desired height above the heating chamber: During manufacturing, thedimensions of the partsmay be adjusted sothat the humidifier pan 1T may be moved toward or-away from'the'h'eating chamber Tin'order to'control therate at which the. water is heated l and evaporated:

Dry or unhumidified'tairenters the humidifying chamber through the louvers'or ports. provided along the lower portion of thecabinet-walls. I5. The-dryairabsorbs moisture" from theiwater provided'in pan-l1. The'rapid passage of heated a y'th a piratinsir ng; causes. apressure differential at the ring which draws the humidified'a-ir into the heated air. stream.

The air tobeheated has'an unobstructedfiow through the heater andpasses alongthefins and the heated convection shells which: reduces-the tendency of-air to form .an insulating film around these h'eatingsurfaces: The turbulence. rings, which" are one' .offth'e: important. features; of. the

invention; accomplish turbulentmotion of the air alongthe radiating surfaces and even further-reduce thethicknesses" of the stationary. air. films. Theheatingchamber, because of the combination of thelouvers in thejcabinetand'the turbulence rings is' substantially a black' body and thus transfers heat only to the air that is passing through the chamber.

By means of the heating arrangement .of the invention, the air is vented rapidly enough through the chimney to cause an aspirating effect which may be used to mix humidified air with the dry heated air. The flow of air through the space heater provides adequate circulation for heating purposes, but does not cause excessive air movement in the room.

Features of my invention that are believed new are expressly set forth in the appended claims.

I claim:

1. In a space heater of the class described, a cabinet having anair vent at the upper end thereof and an air inlet port at the other end, heating means including a heating chamber, a heating element supported within said heating chamber, and a chimney disposed within said cabinet, said heating chamber having an inlet which communicates with said inlet port of said cabinet and an outlet which communicates with the inlet end of said chimney, said heating chamber having a plurality of turbulence rings formed in the upper and lower surfaces thereof, the outlet end .of said chimney communicating with said air vent in said cabinet, and air diffuser means supported on said cabinet adjacent the outlet of said chimney.

2. In a space heater of the class described, a cabinet having an air vent at the upper end thereof, cold air inlet ports at the other end thereof, and humidifying air inlet ports vertically spaced above said cold air ports, heating means including a heating chamber, having a heating element supported therein, and a chimney disposed within said cabinet, said heating chamber .having an inlet which communicates with said cold air inlet ports and an .outlet which communicates with the inlet of said chimney, the outlet end of said chimney communicating with the interior of said cabinet, means for humidifying the air entering said cabinet through said humidifying air inlets, and means for locating the outlet of said chimney and said air vent in said cabinet so that movement of heated air out of said chimney effects a pressure differential which is operable to move air through said humidifying air inlet ports into the interior of said cabinet, and into said heated air stream.

3. In a space heater of the class described, a cabinet having an air vent at the upper end thereof, cold air inlet ports at the other end thereof, and humidifying air inlet ports vertically spaced from said cold air ports, heating means including a heating chamber, having a heating element supported therein, and a chimney disposed within said cabinet, said heating chamber having an inlet which communicates with said cold air inlet ports and an outlet which communicates with the inlet of said chimney, said heating chamber having a plurality of turbulence rings formed in the upper and lower surfaces thereof, the outlet end of said chimney communicating with the interior of said cabinet, means for humidifying air within said cabinet, and means for locating the outlet of said chimney and said air vent in said cabinet so that movement of heated air out of said chimney effects a pressure differential which is operable to move air through said humidifying air inlet ports into the interior,

of said cabinet, and into said heated air stream.

4. In a space heater of the class described, means defining the walls of a cabinet having an upper air vent, heating means including a heating chamber, and a chimney, said heating chamber being defined by vertically spaced upper and lower pans supported on said walls, a centrally disposed air outlet in said upper pan, said pans each including a plurality of concentric turbulence rings, air inlet ports in the walls of said cabinet intermediate said pans, a heating element located centrally in said cabinet and supported between said pans, radially disposed fins attached to said bottom pan extending outwardly froma position adjacent said heating element, said outlet in said upper pan communicating with the inlet end of said chimney, the outlet end of said chimney communicating with the interior of said cabinet and said upper air vent so as to define an aspirating ring, humidifying means disposed within said cabinet above said heating chamber, and secondary air ports in said walls of said cabinet, whereby heated air flowing through said chimney draws humidified air into said flowing, heated air at said aspirating ring.

5. In a space heater of the class described, mean defining the walls of a cabinet having an upper air vent, heating means including a heating chamber, and a chimney, said heating chamber being defined by vertically spaced upper and lower pans supported on said walls, a centrally disposed air outlet in said upper pan, said pans each including a plurality of concentric turbulence rings, air inlet ports in the walls of said cabinet intermediate said pans, a heating element located centrally in said cabinet and supported between said pans, radially disposed fins attached to said bottom pan extending outwardly from a position adjacent said heating element, said outlet in said upper pan communicating with the inlet end of said chimney, the outlet end of said chimney communicating with the interior of said cabinet and said upper air vent so as to define an aspirating ring, a plurality of spaced-apart flow directing shells supported upon said heating element and disposed generally parallel to the walls of said chimney, humidifying means disposed within said cabinet above said heating chamber, and secondary air ports in said walls of said cabinet, whereby heated air flowing through said chimne draws humidified air into said flowing, heated air at said aspirating ring.

6. In a space heater of the class described, means defining the walls of an elongated, vertically extending cabinet having an upper air vent, heating means including a heating chamber and a chimney, said heating chamber being defined by a pair of generally horizontally extending vertically spaced, downwardly dished pans supported on said walls of said cabinet, said pans each including a plurality of alternately concave and convex, concentric turbulence rings, air inlet ports in said walls of said cabinet intermediate said pans, a horizontally disposed heating element located centrally in said heating chamber supported between said pans, vertically disposed fins attached to said lower pan extending radially outward from a position adjacent said heating element, a heated air outlet in said upper pan, said outlet communicating with the inlet end of said chimney, the outlet end of said chimney communicating with said air Vent in said cabinet. and a plurality of concentric, generally cylindrical, spaced-apart fiow directing shells supported upon said heating element and disposed parallel to the walls of said chimney.

'7. In a space heater of the class described, means defining the walls of an elongated, vertically extending cabinet having an air vent in the upperend thereof, heating means including a heating chamber and a chimney disposedwithin said cabinet, said heating chamber being: defined by a pair of vertically spaced: generally horizo'ntally extending, downwardly dished pans supported on: said cabinet walls; air inlet: ports in air outlet in said upper pan, the outl'etendofisaid chimney communicating With the interior of said cabinet and said air vent in a manner adapted to cause a pressure diiierentialoperable todraw air from the interior of said cabinet upon the passage of air through said chimney, apan for containing water, disposed around said chimney, secondary air ports in said cabinet'walls for sup plyin'g unhumidified air to the interior of 'said cabinet; and a generally conical air diffusing member disposed Within said air vent adjacent the outlet of said chimney.

a' spaceheater of the class described, means'defining the walls of anelongatedjvertically extending cabinet having an air vent at the upperendthereof, heating means including i aheating-chamber and a chimney, said heating chamber being positioned adjacent the lower'end ofsaidcabinet and being defined by a pair" of generally horizontally, extending; vertically spaced-apart pans whichare supported'on said walls of said, cabinet, said, cabinet walls havin cold air inlet ports formed therein. intermediate said panda horizontally disposed heating element located centrally of said heating: chamber and. supported between said pans, a heated. air outlet in the central portion of said upper pajn, said outlet communicating with the inlet of said chimney, said chimney extending upwardly, and having its outlet end in communication Withjthe interior of said cabinet and with said. airventin the upper end of said cabinet, said cabinetwalls having' humidifyin'g air inlets formed, therein a which are vertically spacediabove the upper .of

saidpans, means for humidifying thev airflentering' said cabinet through said ,hiunidifyingc air inlets, and means for locating the outlet, of said chimney relative tosaid' air. vent in said cabinet so thatmovement of heated air LltOf said chimney: efiects a pressure difterential which isoperable, to move air through said humidifying air ports intothe interior of said cabinet and into the heated air stream, 7 p

KADOR GEORGE ANDERSON.

REFERENCES CITED The following referenlces are'o-f" record in the file of this patent:

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