US2295502A - Heater - Google Patents

Description

E. LAMB Sept. s, 1942.

HEATER Filed May 20. 1941 F 'IE Q INVENTOR fda/ara' amb 9M ATTORNEY;

Patented Sept. 8, 1942 UNITED STATES PATENT FFICE 8 Claims.

This invention relates to an air heater, and has for objects, an improved air heater for use in heating air in an enclosed area, or for heating air and directing such air at a relatively high velocity, and with relatively small dispersion to any desired point.

Another object is an air heater adapted to use compressed air as the motive power for moving air to be heated over heating means in the heater and for discharging the air heated by said means, at a relatively high velocity and relatively high temperature, into a room or elsewhere, as may be desired.

Another object is an air heater adapted to more rapidly circulate air in a room in a larger volume per minute over heating elements in said heater, than heretofore, and in which heater the motive power for so circulating the room air is compressed air that adds fresh air to the room air at the same time such compressed air functions to circulate the room air.

Another object is a compact, relatively small and light air heater that is free from moving parts, such as a fan, motor or blower, and which heater is adapted to discharge a strongv and concentrated current of hot air in a relatively large volume per minute wherever desired.

A still further object is the method of heating the air in a room by inducing circulation of the room air through compressed air ejector placed f in such room and causing all of the air so induced to flow through the ejector to pass over heated surfaces both before and after such air is mingled with the compressed air that is discharged by the ejector into said room.

Other objects and advantages will appear in the description and drawing.

In the drawing,

Fig. 1 is a sectional view taken vertically through my heater, the source of compressed air being diagrammatically illustrated.

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1.

Fig. 3 is a sectional view taken along line 3-3 of Fig. 1.

Fig. 4 is a diagrammatic view illustrating a modified form of' device.

In detail, my heater comprises an elongated, open ended, tubular member I having a bore I therethrough of generally venturi-shape, the throat thereof being close to one end. This member I is preferably of sheet metal having good heat conductive properties, and adjacent said one end is a hollow, generally frusto-conical member 2, coaxial with said bore, the larger 55 diameter end of said member being threadedly secured within the said open end of the member I for axial movement relative to the latter, while the smaller diameter end of member 2 extends slightly into the neck of said bore. The outer side of member 2 and inner side of the adjacent end portion of member I are spaced apart to provide an annular chamber 3 coaxial with the bore of member I, which chamber is disposed at the side of the restricted neck of member I that is adjacent the threaded connection between members I, 2.

The outer side of the smaller diameter end of member 2 is spaced from say about .002 to .005 inch from the inner side of the neck 4 of member I, thus providing an annular aperture around the bore of member I at said neck. The adjacent sides of the said end of member 2 and said neck, are substantially parallel with the longer sides of member I, and as the taper of said latter sides from the neck toward the end of member I opposite said neck is relatively slight, the said adjacent sides of member I and said neck may be said to be substantially parallel with the central axis of member I. Thus, air under pressure entering chamber 3, will be ejected into bore I' for movement toward the end of said bore that is opposite member 2, for discharge from said latter end. This movement of such air will induce a flow of air into the ared or larger diameter end of member 2 for passage through bore I for discharge from the end of the latter opposite said member 2.

Around the member I are electric heating elements, generally designated 6, which elements are conventional, and are preferably enclosed in elongated, relatively thin metal shells that are secured against member I by any suitable means, to efliciently transfer heat to said member I on one side while heating air that may contact their opposite sides that face outwardly of the member I. Said shells extend longitudinally of member I, to reduce resistance to air to be moved longitudinally of member I outside the latter.

An outer tubular shell 'I, encloses member I, and is coaxial with the latter and spaced outwardly of the elements 6. The one end of said shell extends axially of member I past member 2, and a head 8 closes the end of the shell that so projects past said member. Head 8 extends over the central opening in member 2, but is spaced therefrom so that air passing between shell 1 and member I may be freely drawn into bore I through the central opening in member 2 when compressed air is ejected into bore I from chamber 3.

The end of shell 1 opposite head 8 may terminate substantially even with the corresponding end of member I, and an extension 9 may be provided on member I projecting outwardly of shell 1 from the said end of the latter. The inner sides of extension 9 `are preferably formed so as to be in continuation of the sides of bore I in direction longitudinally of the latter, with the bore of extension 9 coaxial with the axis of bore I.

At the end of extension 9 connecting with member I, the said extension carries a radially outwardly projecting flange 9, which flange connects with the end of shell 1 adjacent thereto. The adjacent ends of member I land extension 9 may be slightly overlapped, as shown in Fig. l, and thus the iiange 9 will function to support said adjacent ends coaxial with shell 1, and to secure extension 9, member I and shell 1 together with the corresponding ends of member I and shell 1 spaced apart.

This flange 9 is formed with an annular row of openings IB, the total area of which is at least the cross-sectional area of the smaller diameter end of member 2, although the aggregate area enclosed by openings Il! is preferably slightly greater than said cross-sectional area of the small end of member 2.

An annular disk II (Fig. 2) or valve, is positioned around extension 9 and against one side of iiange 9', and which disk carries a row of .openings I3 adapted to register with holes I3. Disk valve II is rotatable on extension 9 and slidable against the side of flange 9', it being held against the latter by any suitable means, such as lugs I4. By this construction, rotation of disk II will result in the holes I3 being moved from registering relation with holes IIB, to any desired out-of-register position, until the holes I are completely closed by the material on disk II between holes I3. Upon such movement to said closed position, the area of holes IIJ, will, of course, be progressively decreased, and upon reverse movement of disk II from said closed position, the said area will progressively increase until the holes ID, I3 are in register, and in which latter position air will be admitted to between shell 1 and member I, to the full capacity of holes I 0.

A handle I5 may be provided on disk I I for turning the disk, and stops I may be also formed on the periphery of said disk II to cooperate with one of the lugs I4 for limiting the rotative movement of disk II in one direction or the other.

The flange 9 may be removably secured to the adjacent end of shell 1 by screws I1, to enable removal of the extension 9 and said flange 9 and disk II from shell 1 and from member I.

The inner sides of shell 1 are preferably covered with asbestos I8 or any suitable heat resisting and heat insulating material, as may head 8, and head 8 with its asbestos lining thereon may be removably secured to shell 1 by any suitable means, such as screws I9.

To space the end of member I that carries the element 2 from shell 1, I provide three or more equally spaced spacers 23 at three or more points around said end of said member I, which spacers are secured in place by bolts or screws 2I extending through shell 1 and into sockets formed in the outer sides of member I.

Compressed air is admitted into chamber 3 by a pipe tting 22 that extends from said chamber through shell 1 to outside the latter, where a compressed air line 23 connects the pipe 22 with a compressed air tank 24, which tank receives its air in the usual manner from a compressor 25. A valve 26 is interposed in the air line leading to chamber 3 to control the air admitted into said chamber.

The heating elements 6 are conventional, and are heated by electricity conducted thereto by wires 21 connected with any suitable source of electricity, and any one of the conventional control devices 21 may be provided in the electrical circuit for regulating the temperature to which elements 6 are to be heated.

In operation, the heating elements E are energized, and valve 26 is opened the desired degree, whereupon the compressed air ejected from chamber 3 through the annular aperture adjacent neck 4, will induce a rapid and relatively large flow of air through openings I, I3 into passageway P, and over the heating elements 6, and from thence through the central opening in member 2 into the heated bore of member I for discharge from member I into extension 9 and out of the device. It will be noted that the compressed air that causes this flow of air, is slightly pre-heated in chamber 3, and in pipe 22 where the latter crosses the space between shell 1 and chamber 3, and it is then driven directly along the heated inner surface of bore I for more heating as it intermingles somewhat with the hotter air drawn over elements 6.

The heater, as described to this point, may be a iixed installation in a room or wherever desired, but for many uses, I mount the heater on a portable standard 30 that is vertically adjustable on a supporting base B to any desired height above a supporting surface on which base B may rest.

A vertical pivot 3I on said standard carries a bracket 32 having arms at opposite sides of shell 1, which arms support horizontal pivots 33 secured to said shell for swinging the heater in a Vertical plane to direct the discharge end of extension 9 at any desired angle, relative to vertical, in said plane. As the heater may swing horizontally on pivot 3|, it will be seen that the discharge end of extension 9 may be quickly moved to direct the air discharged therefrom in any desired direction. A set screw 34 may lock the heater at any angle in said vertical plane, while a set screw 35 may lock the pivot 3I against horizontal swinging of the heater, and a set screw 35 may support standard 3U at any desired degree of vertical extension relative to base B.

For example in a paint shop, this heater may be directed onto the work to be dried by the hot air discharged from extension 9, or if the heater is in a room, or enclosed area, for heating the air therein, the discharge end may be directed to cause a circulation of heated air in such area along the oor and back by way of the ceiling and two opposite side walls to the openings I0, I3 for recirculation through the heater and additional heating of such air, or the direction of circulation in the room or area can be varied.

In conditioning and heating the air in a room, the compressor may be outside the room, and thus, a small amount of fresh air will be continually heated and mixed with the air in the room.

In drying the inside of a tank or the like, the compressor and heater may both be .in the room, and the circulation of the same air in the room through the heater will become extremely hot.

It is vital to the satisfactory performance of my heater, that the annular aperture for the compressed air at the throat of bore I', be very small and that it be so formed as to eject the air into the bore generally parallel with the axis of said bore, for otherwise the volume of air induced to flow through the heater in relation to the volume of compressed air would be so small as to be of no practical value.

The velocity of the compressed air ejected into bore I may be modified by adjusting the element 2 axially of bore I. If member 2 is screwed farther into bore I', the size of the annular aperture is decreased, thus reducing the volume of air ejected through said aperture per minute and increasing its velocity, while the opposite result occurs if the member 2 is screwed in direction axially outwardly of said bore.

A partial closing of valve II, will manifestly reduce the volume of air per minute that enters passageway P and thus it will be seen that by the adjustment of either member 2, or Valve II, or valve 26, or control 21', or by the relative adjustment of several or all of the various means disclosed for controlling air flow as to velocity, or volume or the temperature of heating elements, it is possible to obtain practically any desired result.

While I have shown the member I as being of sheet metal where the latter forms part of chamber 3, it is obvious that all walls of chamber 3 may be of cast metal, including neck 4, and the member I may be merely a tapered discharge nozzle, connected therewith. structural details disclosed are not to be considered restrictive to such details, but rather in their functional characteristics for accomplishing the broad results intended.

In Fig. 4 I show a modified form of device, in e which the flange 9 and disk II of Fig. 1 are replaced by an imperforate flange 36 and radially directed openings are in shell 1 adjacent said flange. In this instance, different gases may be admitted to one or more of such openings from separate sources, such as tanks 31 for mixing with the compressed air or other compressed gas from tank 38 and the control of the resultant heated mixture discharged from extension is readily obtained, by the valves 39 in the pipe lines communicating between tanks 31 and the interior of shell 1.

This particular heater is useful in certain drying, fumigating or air conditioning processes where it is desirable to either add a gas to the air or to eject a single gas or controlled mixture of different gases from the nozzle or extension 9.

Having described my invention, I claim:

l. The method of heating air within a room or enclosed area that comprises; inducing circulation of the air in said room through a compressed-air-actuated air induction nozzle positioned in said room by ejection of compressed air into and from said nozzle into said room; conducting the air in said room, so induced to circulate, through a passageway separate from the room-air and nozzle directly to said nozzle for flow through the latter; heating said room air as it flows through said passageway and thereafter further heating the room air together with the compressed air ejected into said nozzle before ejection of said room-air and compressed air into said room.

2. The method as defined in claim 1, in which the room air and compressed air ejected from said Thus the specific f nozzle is re-heated and re-ejected from said nozzle in association with compressed air continuously ejected into said nozzle and room.

3. The method as defined in claim 1 in which said compressed air consists of fresh air conduced to the nozzle from outside said room.

4. An air heater and blower, comprising; an elongated, tubular, air induction nozzle having an air inlet at one end and a discharge outlet at its opposite end; the bore of said nozzle being formed with a throat of substantially venturishape adjacent said inlet, and the bore at opposite sides of said throat extending divergently therefrom longitudinally of the nozzle; an annular aperture extending around said bore adjacent said throat opening axially of the bore toward said outlet and positioned to eject compressed air into the portion of the bore extending between said throat and said outlet; a tubular shell enclosing said nozzle and spaced therefrom with the exception of said outlet and formed with an opening for air in the portion thereof adjacent said outlet thereby providing a passageway for air outside said nozzle communicating between said opening and said inlet; means for conducting compressed air to said aperture for ejection therefrom for inducing a flow of outside air through said passageway and said bore of said nozzle for discharge from said outlet; heating means in said passageway for heating the air in said passageway prior to said air entering said inlet for passage through said nozzle to said outlet, said last mentioned means being arranged and adapted to heat the walls of said nozzle for heating the air passing through the bore of said nozzle.

5. In a construction as defined in claim 4, an open-ended tubular extension on said nozzle coaxial therewith extending outwardly from said outlet to a point remote from said shell.

6. In a construction as defined in claim 4, the means for conducting air to said aperture including an annular chamber disposed in said passageway, the interior of which communicates with said aperture at all points around the latter.

7. An air heater comprising; a compressed-airactuated air-induction nozzle having a through bore providing an inlet for air at one end and a discharge outlet for air at the opposite end, and formed with an aperture opening into said bore intermediate said inlet and outlet; said aperture being directed toward said outlet for inducing a flow of air through said bore from said inlet to said outlet upon ejection of compressed air into said bore through said aperture; means for conducting compressed air to said aperture for ejection therefrom into said bore in direction toward said outlet; heating means between said aperture and said outlet for heating the walls of said bore for heating air adapted to flow therethrough from said aperture to said outlet; a passageway for conducting outside air over the outer sides of said nozzle to said inlet in heat exchange relation to said heating means for pre-heating air admitted to said inlet.

8. In a construction as defined in claim '1, valve means for regulating the volume of air to be conducted over the outer sides of said nozzle to said inlet; means for varying the volume of compressed air conducted to said aperture; means for Varying the volume of air to be ejected into said bore from said aperture; and means for varying the temperature of said heating means.

EDWARD LAMB.

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