US2576685A - Forced air circulation combustion type space heater - Google Patents

Description

Nova 27, 1953 K. S. JENSON FORCED AIR CIRCULATION COMBUSTION TYPE SPACE HEATER Filed Nov. 18, 1947 2 Sl-IEETSSHEET l o a o u o o ZNVEN TOR. flwzm 5. Y 15/1 50 K. S. JENSON Nov. 27, 1951 FORCED AIR CIRCULATION COMBUSTION TYPE SPACE HEATER 2 SHEETS-SHEET 2 Filed NOV. l8, 194? INVENTOR. Kf/v/vzr/ 5. Zwjo/v Patented Nov. 27, 1951 FORCED AIR CIRCULATION COMBUSTION TYPE SPACE HEATER.

Kenneth S. Jenson, Wisconsin Rapids, Wis., as-

signor to Prentiss-Wabers Products Company, Wisconsin Rapids, Wis., a corporation of Wisconsin Application November 18, 1947, Serial No. 786,651

Claims.

This invention relates to a space heater of the type in which a combustion chamber is positioned within a surrounding cabinet. In the description to follow, the heating unit is exemplified by an oil burner which is disposed within the lower end of an upright combustion chamber in the form of a cylindrical drum which is disposed within the cabinet in spaced relation to its walls and top. A space heater of this general description is well suited for small homes, stores, shops and the like.

For its objects my invention here is concerned with optional conversion of a space heater of the natural circulation type to one of the forced circulator type by application thereto of a blower unit; with the construction of the heater cabinet which facilitates the attachment thereto of the blower unit on the cabinet rear wall over an openll'lg therein provided by displacement of a knockout closure section; with the discharge nozzle l forming part of the blower unit which forces a thin stream of air over a primary heating surface to be reheated preliminary to its delivery from the cabinet; with the means provided for forced discharge of highly heated air in a thin stream in a downwardly inclined direction from the cabinet; with the arrangement of passages provided withinthe cabinet front at a point close to its top for movement of heated air to and through the blower unit; and with the blower unit itself and the protection afforded to its operating motor; and with various other features of construction which will be specifically referred to hereinafter. A space heater having these various features of construction is greatly improved in its performance, and the heated air discharged therefrom will continue its movement to a distant point in the room where it is most effective and comfortable for heating purposes.

Objects and purposes such as these, and also others which will be hereinafter noted, may be realized from a construction such as is illustrated in the accompanying drawings wherein:

Figure 1 is a plan view of a space heater which embodies the features of my invention;

Fig. 2 is a view in vertical section taken on line 2-2 of Fig. 1;

Fig. 6 is a fragmentary view in elevation of the rear wall of the heater cabinet, showing the knock-out panel provided therein adjacent the flue thimble which extends outwardly of the wall; and

Fig. 7 is a horizontal section taken on the offset line 1-1 of Fig. 2;

The space heater of this invention comprises a cabinet C having a front wall l0 rising from a bottom II and joining with side walls l2 which are interconnected by a. rear wall IS. A top wall I6 is carried by and supported by the remaining vertical walls. The cabinet top is provided with a grille which may comprise a plurality of forwardly inclined depending louvers I! which define between them narrow vertical slits. If desired, the cabinet may be supported slightly off the floor as by means of a plurality of feet (not.

shown).

Within a cabinet of this general description is a platform raised slightly from the bottom for support of an upstanding combustion chamber in the form of a drum D. The top 28 of the drum is slightly upwardly convex in contour and spaced from the cabinet top wall iii a. substantial distance to provide therebetween a horizontal pasi sageway t having at its front a forwardly inclined depending baffle shield 21. This baffle shield provides, in effect, a louver to deflect downwardly the air passing out through an elongated delivery opening 0 therebelow formed in the front of the cabinet and defined in part by a head plate 22 also extending downwardly and forwardly from a point adjacent the drum top at its front toward an outstanding panel 23 which may constitute a door for the cabinet front wall Pig. 3 is a side elevation of the blower unit uni I Fig. 5 is a view in front elevation of the blower If desired, this head plate 22 may be apertured at 24 in the form of a grille, both for ornamentation and to provide escape openings for air ascending through the passageway a between the drum and the cabinet front panel 23. This panel extends for the major portion of the width of the cabinet (see Fig. '7) and down to a point relatively close to the bottom thereof. Closely below the panel is an elongated slot 25. extending crosswise of the cabinet to provide therefor an inlet opening for air which is to, be circulated upwardly therewithin. Another inlet opening in the form' of an elongated slot 26 may also be provided in the rear wall l5 at a point close to the cabinet bottom for the same purpose.

'The heating drum D is positioned centrally within the cabinet so as, to be spaced from all its 1 walls, including the top l6 below which thehori- 5'5 ggntal top passageway t is provided v um in its bottom region is place P-.

thin the here shown as the pot type, to which fuel oil may be fed through a pipe 39 which leads from a control unit iii. A supply tank 32 supported at the rear of the cabinet between bracket plates 33 is connected by a pipe 34 with the control unit to assure a gravity feed of oil thereto for operation of the burner.

From an opening in the rear side of the drum D, in its upper region, is extended a flue thimble 38, passing through the rear wall l of the cabinet to connect with the elbow Slof a flue pipe 38 for eduction of the products of combustion into a stack or chimney (not shown). So that this thimble may be of minimum length, it is located in the center of the back wallof the cabinet. and

relatively close to its top so as to connect with the heating drum at a high-up point.

The space heater thus far described is complete and operative as a radiant type of heater. The air entering through the base inlet openings and 26 is free to ascend along the heating drum within'the passageway b rearwardly thereof, and also within the somewhat wider passageways 0 upon opposite sides thereof. To-a certain extent this is true also of the air ascending within the front passageway a which may be partly closed at the top, by the head plate 22. In this upward movement the air is raised to a high temperature by convection, and in this condition escapes through the grille in the cabinet top I 6, and perhaps also i through openingsin the head plate 22, if pro vided therein, to enter the room into which additional heat is also transferred by radiation from the heated walls of the cabinet. A space heater.

so operating is effective to heat a room but only within a short radius; it cannot operate efiective-' ly as does a forced circulator type of heater, to deliver the heat to a more distant point. To provide for a forced circulation and discharge of the heated air through the delivery opening 0 at the front of the cabinet near its top, and therebyconvert the heater to one of the forced circulator type, I have arranged blower means of a novel character now to be described.

A blower unit B, complete in itself, is optionally attachable to the rear wall 15 of the cabinet to discharge therefrom the air which is heated.

therewithin. This blower unit fits over an opening. it formed by displacement of a knock-out section K having its margins spaced very slightly by a narrow slit as from the cabinet read wall i5 to which it may remain connected by tenuous webs 4 l. Such a section may readily be displaced from the cabinet wall with which it is initially joined integrally by pressing its opposite ends inwardlyand then bending the panel back and forth until it becomes loose and free. The opening is vacated by the knocked-out section K isv located in part overthe thimble 36 (see Fig. 6). It also extends laterally to one side ofthe thimble and angularly in a downward direction with its low end formed substantially as a semi-circle.

The blower unit B comprises an elongated housing which atone end is enlarged and rounded in the general form of a scroll s, the housing extending laterally therefrom ,to provide a duct cl whose rear wall is curved around forwardly in the form of an elbow (see Fig. 1). This duct opens out in the form of a generally rectangular mouth opposite the wall opening is at a point above the fine thimble 36 (see Figs. 5 and 6) where it joins with a nozzle N from which the heated air issues in .the form of a stream which is vertically thin..and horizontallyLwide, nczzle'may be secured fixediy tc'th'erorward'sice' I with.

n; in.)

sure on all the parts carried thereby.

of the blower housing so as to require no other support. As shown, this nozzle comprises a lower channel piece 41 facing an upper channel piece 48 to which it is joined, both channel pieces being upwardly inclined, but the former more so than the latter so as to be in converging relation there- The upper channel piece continues on beyond the lower channel piece to provide a Shield 5% having depending flanges along opposite edges,

.; the shield at its forward end 5| executing a slight transform the stream of air moving out of the result, the air which may have dropped a few degrees in temperature during its passage through the blower unit will be reheated in passing'over the'drum preliminary to its dischargev through the delivery opening 0 in the cabinet front at a point close to its top.

The blower unit 33 comprises also arotor 55 (see Fig. 3) which may take the form of the C011".

ventional squirrel cage, tharotor being located eccentrically in the scroll end 5 of the blower: housing (see Fig. 5.). wherea large circular inlet opening thereinto is fitted with a collar 55. Thisrotor is carried by a shaft '51. which extends] through one end of a housing M containing. an glectrical motor so as to be directly driven'there- The motor housing M is afiixed at one end to a'vertical'base plate 66 (see Fig. 4) formed with a plurality of" offset feet 6| through each of which is extended a bolt 62 which passes also through a bracket plate 65 and on through a spacer sleeve 56. Continuing, this bolt also passes through a shield 61 spaced from the bracket plate and from the proximate rear wall of the housing 5 through which the bolt is'extended to present-its head 68 against the innerface thereof. A look nut 59., also threaded onto the bolt, may engagewith the outer. face thereof. Bysome such means as this each bolt. is carried rigidlyb'y the blower housing rear wall.

from which it extends outwardly to secure the various parts just described. Threaded onto each bolt upon opposite sides of the feet 6| of the baseplate are grommets ill to the. outer side" of which are arranged washers, a nut.'l2 being theaded onto the bolt to exert a clamping presassembly is desirably provided for each foot of the base plate tosecure the motor immovably upon the exterior of the rear wall of the blower housing.

The bracket plate 55 which stands in spaced relation to both the motor and the cabinet rear wall is extended beyond the motor both vertically and horizontally to shieldit from the heat which radiates .f'ron'i theiblow'er housing, The

' shield '6!also"interveues'between the" brack t. plate and the cabinet; being spaced from 'a'cli' Such an by an air gap which is open on all sides so as to further prevent the transmission'oi heat outwardly toward the motor. Since the motor is spaced laterally from the flue pipe 38 by only a short distance (see Fig. 1), I have arranged at the end of the bracket plate 65 a lateral extension I5 which serves as a shield to protect the motor against excessive temperature at that point.

The collar 56 surrounding the inlet opening into the blower housing is formed to provide frictional bearings 18 for a rod 80 one end of which is turned to provide a crank 8|. Afiixed to this rod and concentric with the circular collar 56 is a damper 82 which, in the position of Fig. 5, substantially closes the inlet opening into the blower housing. The operating crank 8| may be turned to adjust this damper to any selected rotative position whereby to control the amount of heated air entering into the blower housing.

Electrical energy for operating the motor is conducted through insulated wires contained in an extension cord 85 which is encased for a substantial distance by a conduit pipe 36 having brackets 81 and 88 to facilitate its fixed attachment to the rear wall of the cabinet. By the provision of such a conduit pipe extending from a point adjacent the motor downwardly toward the lower end of the cabinet, ample protection is afforded to the extension cord against excessive heat which otherwise might prove dangerous to the electrical connections.

The air circulating space heater of this invention is advantageous in numerous particulars. Perhaps a feature of primary importance is the arrangement whereby air heated to a maximum temperature within the cabinet is drawn into the blower at a high-up point, and then discharged therefrom, in the form of a verticallythin, horizontally-wide stream, close to the primary heating surface at the top of the heating drum where it is subjected to reheating; the air at this point of maximum temperature is then delivered outwardly and downwardly from the front of the cabinet at a point close to its top to proceed therefrom toward the opposite end of the room at a low down level. This stream of air which is driven outwardly from the cabinet in no wise impairs the heating by radiation in the lateral area close to the cabinet or the heating by convection in the area thereabove. The air forced out to the front and downwardly is intended rather to reach a more distant part of the room. perhaps even passing through an open doorway into another room therebeyond.

When distribution of heat takes place by natural convection the result is a high temperature in the u per portion of the room and in an area close to the heater cabinet, but adjacent the floor and at some distance from the heater the temperature is relatively low. As a result there is less comfort to the occupants of the room, and

the expenditure of more fuel and heat is re-.

quired to attain a desired comfort level. By the heater herein disclosed, I am able to-force a substantial portion of the heated air out to a greater distance from the cabinet, in a comparatively narrow'stream that issues from a point near the top of the heater cabinet in a direction angularly downwardly toward the floor. heat tends to rise readily, it is desirable, in order to obtain mechanicaladvantage for the distance to be reached, that the heated air should bedis charged angularly toward and .at some distance Inasmuch as from-the floor to attain lateral distz'nce. -While 7c 6 it is possible by using suflicient force to attain lateral distance when the air is discharged at lower levels, comfort is noticeably lacking in such circumstances and the faster moving air stream may be noisy and may also pick up dust and dirt which will be dispersed throughout the heated area.

By my invention the high temperature air is discharged from the heater at a point, adjacent its top at moderately high velocities. Its movement proceeds angularly downwardly toward the floor and then in a generally horizontal direction close to the floor. When it has first advanced a short distance from the heater, the air tempera-' ture begins to reduce due to its diffusion with cooler air. By the time the air has reached the floor its temperature is reduced below the danger point so that overheating or scorching of finishes or coverings will be avoided. By diffusing the high temperature in the manner explained a large quantity of heat is delivered to the greatest possible distance from the heater at a comfortable temperature; at the more distant points its velocity is reduced somewhat so that the heated air will rise and diffuse in its entirety within the remaining cooler air of the room.

Another feature of importance inherent in this invention is the blower unit itself which is attachable to an existing heater cabinet, or may be aiiixed thereto at the time of its manufacture or sale. For convenience in shipping, and otherwise, it may be preferred to install the blower unit on the cabinet at or about the time that the space heater is to be delivered for use. This blower unit is designed for aflixation to the cabinet rear wall at the point where it will be most efiicient in operation, 1. e., directly over the flue duct which extends laterally from the heat ing drum at a point relatively close to its top. At this high-up level the air ascending through the passages a, b, c, and {1 will have attained its highest degree of temperature. It is at this point that the air is drawn into the blower through its inlet opening and then circulated therethrough and out again through the forwardly extending nozzle directly over the top of the heating drum. Here a reheating 'of the air takes place preliminary to its discharge from the cabinet at the front. By this arrangement the blower circulates and discharges heated air which has reached a point of maximum temperature, and just prior to its emergency from the cabinet reheats the air so that at the moment of its delivery into the room its temperature is at the' very highest point.

By the various other minor features hereinbefore described I safeguard the motor from the surrounding temperatures which may be considerable. On the two sides which are proximate to the cabinet and to the flue the motor is protected by shields with intervening air spaces which will promote ventilation. The resilient grommets employed in connection with the bolts which secure the motor base to the cabinet rear wall serve also to eliminate vibration and noise. The motor although positioned in a zone of relatively high heat may be depended upon to operate over a long period without danger due to the protection afforded by the means described.

I claim:

1. An air circulating space heater in which is combineda cabinethaving base inlet openings and in its upper region outlet openings for escape of heated air and at its front close to thetop ahorizontally *exteirdm'g, downwardly unarmed;

acre-68c 7. louver for deliveryofair 1n a directiontoward the floor-and; forwardly of the heater, said cabinet beingalso provided with ablower unitopening located at the back of the cabinet intheupperregion thereof, a-combustion chamber within the cabinet in spaced relationto its :walls and top, and a blower unit having a housing attache abletov the cabinetyrearlwall in covering relationtoathe blower unit opening therein and formed with spacedinlet and outlet apertures oppositethe-cabinet opening, a nozzle extended from the outlet aperture of the housing inwardly of the cabinet witha horizontally wide and vertically thin dischargeopening close to. the cabinet top at apoint above the combustionchamher and inclined downwardly toward the top of thecom-bustion chamber and toward the delivery louver thereb-eyond through thewfront wall ,of the cabinet-a motor carried by the housing exteriorly thereof and a blower in driven relation with the motor-mounted-within the blower housing.oppo-- site the inletaperture adapted to drawin. highly heatedfair from the space surrounding the com bustion chamber and discharge it through the nozzle back across the topofthe combustion chamber to be reheated thereby immediately preceding its forced delivery through the front louver of the cabinet for circulation downwardly and forwardlythereof. j

.-2. air circulating space heater according extending from thecombustionchamber through.

the cabinet rear wall in proximity'to. the motor, and a mounting for-the motor upon the blower housing comprising'connections whereby thermotor is maintained in spaced relation-to the honeing, and an insulating shield intervening between the motor and the housing and between the :motor and thi'mble flue.

5. In an air circulating space heater, the combination of a cabinet having-vertically spacedinlet and outlet apertures therethrough, a combustion chamber fixedly positioned within the cabinet spaced from the walls and top thereof, a finethimble extending *fIOlll ,-the combustionlchamber through the cabinet rear wall and therebeyoncl, .there being an-elongated opening through said wall above and laterally ofthe flue thimble, and a blower unitafiixed to thecabinetrear wall exteriorly thereof in covering relation to the elongated opening therethrough, ,theblower unit comprising a housing-withspacedinletand outlet apertures oppositathe rear wall opening in communication .with the cabinet interior, at iotatable blower withinthe housing opposite the. inlet opening,.a nozzle carried by the housingin surrounding relation to the outlet aperture and extending therefrom into the cabinet within the space between its top and the top of the combustion'chamber, arnotor. afljxedtnthe housing exteriorly .thereofa the blower, and

wait-935 and blower and-serving tosupport the latter with-- in-the housing. 1 r

. 6. In an air circulating space heater, the com-- bination of a cabinet provided-with a base inlet opening and an upperoutlet openingfor escape. of heated air and at its frontadjacent the topv with a horizontall extended, downwardly inclined louver for forced delivery of air ina direction towards the floor and forwardly of the heater, a combustion chamber located within the cabinet and spaced from the walls and topthereof, there being an elongated opening in, the rearwall of the: cabinet, and a blower unitcomprisingau elongated housing fixedly secured to the rear wall of the cabinet upon the exterior face thereof and fitted over the elongated opening in saidrear wall of. the cabinet, a discharge nozzle mounted upon the blower housing and extending through theopening insaid rear wall into the cabinet within the space between itsv topand the combustion chamber therebelow and pointedtowards the louver throughthe cabinet front wall, whereby heated air .issuing from the nozzle will pass over the top of the. combustion chamber to be reheated thereby immediately preceding its forced, delivery through the louver, a blower mounted within the housing for operation therein, and a motor connected with the blower for operation thereof and mounted upon the housing exteriorly thereof, there. being in the housingw l covering the elongated opening in the cabinetrear wall an inl-etaperture opposite the'blo'wer.

7, In an air circulating space. heater, the combination of a cabinet provided with-base inlet openings and upperoutlet openingsforescape of heated air, and at its front adjacentthe top' with a horizontally extended, downwardly inclined louver for delivery of'air in adirection towards the floor and forwardly of the heater, there being an elongated opening in the rear wall of the cabinet. to provide communication with themterior thereof, a combustion chamber located within the cabinet and spaced from the walls andtop thereof, and a blower unit comprising an elongated, housing secured to the rear wall of the cabinet exteriorl'y thereof and covering the elongated opening of said rear wall, said housing being provided with spaced inlet and outlet apertures opposite the elongated opening'in the rear wall of the cabinet to provide communication with the interior thereof, a motor driven blower mounted for operation within the housing opposite the inlet aperture thereof, and a nozzle carried by the housing opposite theoutlet' aperture thereof and extended laterally therefrom through-the elongated opening inthe rear wall of the cabinet into the space intericrlythereof between the top of the cabinet'and -the combustion chamber therebelow and pointed'toward-s' the louver through the cabinet front wall where,- by heated air discharged from the nozzle required to pass over the--top of the combustion chamber immediately preceding its forced olelivery through the louver in adownwardly and. forwardly direction.

8. In an air circulating 'space heater, the combination of; a cabinet having-low .inletand high outlet openings therethrough and adownwardly inclined louver at the cabinet front extending. horizontally in proximity to its top, a drum ar.. ranged within the cabinet spaced from the walls and top of the cabinet and forming a combustion chamber, air circulating means provided withan inlet communicating with .the space between the.

combustion chamber. f rmin drum and the cab:

v .i baaegghthaiiriwaieaioair ing means having a nozzle and provided with an outlet connected to the nozzle, said nozzle being horizontally wide and vertically thin and extending into the cabinet through an opening, thereof into the space between the top of the drum and the top of the cabinet toward said louver and inclined slightly downwardly to direct air issuing from the nozzle toward the top of the drum for impingement against the same for reheating thereby immediately preceding its forced discharge through the delivery louver at the front of the cabinet.

9. In an air circulating space heater, the combination of a cabinet having low inlet and high outlet openings therethrough and a downwardly inclined louver at the cabinet front extending horizontally in proximity to its top, a drum within the cabinet spaced from the walls and top of the cabinet and forming a combustion chamber,

and an air circulating blower unit mounted on ithe rear wall of the cabinet exteriorly thereof and provided with an inlet communicating with the space between the combustion chamber forming drum and the cabinet below the top of the drum, said air circulating blower unit having an outlet and provided with a fixedly extending nozzle connected to said outlet and projecting through an opening in the rear wall of the cabinet and extending into the space between the top of the cabinet and the top of the drum, the nozzle having a discharge opening horizontally wide and vertically thin with a shield projecting from the top of the nozzle and inclined downwardly toward the top of the drum to direct air issuing from the nozzle toward the top of the drum and cause the current of air issuing from the nozzle to impinge against the top of the drum for reheating immediately preceding its forced discharge through the louver at the front of the cabinet.

10. In an air circulating space heater, the combination of a cabinet having low inlet and high outlet openings therethrough and a downwardly inclined louver at the cabinet front extending horizontally in proximity to its top, a drum with in the cabinet spaced from the walls and top of the cabinet and forming a combustion chamber, and an air circulating blower unit mounted on the rear wall of the cabinet exteriorly thereof and provided with an inlet communicating with the space between the combustion chamber forming drum and the cabinet below the top of the drum, said air circulating blower unit having an outlet and provided with a fixedly extending nozzle connected to said outlet and projecting through an opening in the rear wall of the cab inet and extending into the space between the top of the cabinet and the top of the drum, the nozzle having a discharge opening horizontally wide and vertically thin facing toward the louver at the cabinet front with a shield projecting from the top of the nozzle and inclined downwardly toward the top of the drum to direct air issuing from the nozzle toward the top of the drum and cause the current of air issuing from the nozzle to impinge against the top of the drum for reheating immediately preceding its forced discharge through the louver at the front of the cabinet.

KENNETH S. JENSON.

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

UNITED STATES PATENTS Number Name Date 1,169,448 Williams Jan. 25, 1916 1,729,202 Blom-feldt Sept. 24, 1929 1,923,079 Delamere Aug. 22, 1933 1,996,927 Lake Apr. 9, 1935 2,041,870 Shefifield May 26, 1936 2,263,362 Logue Nov. 18, 1941 2,276,614 Grapp Mar. 1'7, 1942 2,348,127 Grimes May 2, 1944 2,386,508 Ripley Oct. 9, 1945 2,398,113 Parrish Apr. 9, 1946

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