US2721546A - Liquid fuel heating apparatus - Google Patents

Description

Oct. 25, 1955 Filed July 10, 1953 M. W. PATRICK LIQUID FUEL HEATING APPARATUS as V 68 V I. \c I. 1 28 3 Sheets-Sheet l J [Ill IN VEN TOR.

MALCOM M4 PATRICK BY A rro/e/vs Y Oct. 25, 1955 M. w. PATRICK LIQUID FUEL HEATING APPARATUS 3 Sheets-Sheet 3 Filed July 10, 1955 INVENTOR. MALCOM W PAr/P/c/r ArroeNE/ 2,1 1 5 LIQUID FUEI; HEAIIN APPARATUS Malcom; W. Batrick, Macedonia,. Ohip assignor to Pen.

f ction.lndustrieslncorporated, ,c9n 9rati0 o h o, ApplicafionJuly-lfl 1953, SeriaPNo, 367,301

laim (Q1! 1 5F Ihisjnyention. relatesgtQ hfiating apparatus; of: the class commonly referred to as space heaters, and, ithas; to-do.

with, irnproyements. in. the design; and. construction of such apparatus, and, with. a unique.- form oh liquid fuel,

bumerespecially adapted, for-use therein,

The, general object: of, my inyention is. to provide an efiicient, natural draft liquid, fuel burning. space heater that. is. designed and: constnucted, for use particularly in temporary or makeshift quarters where: Operating. condi-. tionaarelikely to be unfavorable, and that can;beplaced directly upon the ground if necessary, and: staked; thereto, While. the flue;. that is: incorporated in, the apparatus, is held in, a, substantially vertical position byguy. ropes or similar means.

It is a, further purpose to provide a, so-called, lgnockdown? construction, conSistirlg of relatively few p arts, inch ding a housing ofcomparatively. small compass, which parts are, especially: convenient of assembly and disassembly and, when disassembled, are, with the exception;

of, said housing, capable. of being nested together and,

compactly arranged within the housing. thereby to pro.-. duce a package that convenient of handling, transportation and storage.

Another object of the invention is, toprovide heating apparatus of the aforesaid class, that is simple of con-..

struction, and inexpensive to. manufacture and that willv a.

efficiently andsati fQQtQl'ily burn, liquid. hydrocarbon fuels of' vapious kinds, particularly those. of. a, highly, volatile na ure su h as. gasc ine and hatmay b easiiy an s e y h ed.

Another object is, to, provide a, liquid fuel burner where-. in the p intzof admission of fuel. to the burner casing is so. remote frornthe combustion region that, evenwith highlyvolatile fuels, possibility of flash, back from. such region to the, point of admission is reduced to. a minimum,

Another. object is to, Provide a natural; draft liquid fuel. burning apparat s wher n. t e b rne p oper, i g r of the pot type in principle and is free of any internal, obstruction, that. would interfene with; or reduce theeffectivenessof the n ural draf -t Anothe obiect is to. provide a; burner of the character just described comprising a casing shaped, throughout its lower region to. form a sump, for a pool of fuel and to maintain constan th exp e surf e r a f .11 of given volume regardless of any angle to, which, the. burner may be tilted from vertical, position, within reasonable limits.

The invention readily lends itself to embodiment in he ingpparatus. of av wide. range. of siz s, throughout. which range the apparatu is, proportionately en'ective, As indicative. Qf. itsv cfic tiv ucss, I ay PQint ou that in. a s ructure wherein the heat r h in s pp x m y 30 inches. high and, 7 inches. in. diameter, the; heater is capable of, a fuel burning rate that will, produce a heat Qut-p t.in.tl;1 n ig b rhood. r 30,009 E 7s. pi r hou Auother. object of, the, invention. is, to provide, a liquid uel b r ng ppa u th t l operat o r a W d range of fuel burning rates in a stable and quiet manner with out smoking, and; that will not be affected by such. dis;

turbances as down drafts.

A still further object is to provide anespecially simple, means for effecting a continuous and, uniform flow of fuel to.the vaporizing region, of. the burner at any setting.

of theflow control valve, including those settings respon{ sible for the. lower rates of, fuel. feed th ereby to insure a, steady fireand prevent fluctuationand possibleextinguish;

llfitflf; the flame.

yet further object is,to .provide a construction where: in the parts. interfit: in, such, manner as to be properly located, with respect toone another and tobepositively= held in operative relation without the use offextrinsic fastening means, this feature being. especially valuable, in the knock-downconstruction hereinbeforereferredto,

With. these objectsin view, andothersihat. will become appar n s, this. descript n Pr ee s, t e ve t on. mayv be defined as consisting of the combination. and. arran fii. ment; of partsset 0.1 1. in. the claims annexedt heret o, and llustrated in the accompanying: drawings wherein. like, reference characters designate like parts throughout, the several views.

In the drawings Fig, 1 isa perspective view, of my improved heating ap-v paratus in condition for use, the View: being divideglfinto ott s partsto permit of a rs c e;

EigfZ isacentral vertical section through theapparaf t ts, in knock-down? and compacted condition fortrans; pot a onand tor ge; i

Fig.3 isa section entire line 3 3 of Fig. 2;

F 4 s n. e rged. e al. er ic l se tion. rou h, he a p ra s, with a ue a d. a P t h o n i ermediate, he nds. o the. sli b d nz c a ber o en; i ay;

Fi s a 9: zontalv e t o hr h apparatus imrv mediately above. the bot om 0f the housing, as. indicated b the ass s are. 4.;

F is a t ca ransver e e t n. hro gh he U: ape burne a n ubst nt ly the l e t Fig. 4, showing theadjacent part of the housing andref vealing the interengaged notched portions, of the housing and burner, and

Figs. 7, 8 and 9 are perspectiye views, respectively, of the h usin m the, ho siua ttom and of hshqld downlugs." Y

According to my present preferred construction, the, housing 1 of the apparatus comprises an elongated cylin-. drical wall 2, of sheet rnetai of suitable gauge and quality. At a substantial distance above. its lower end, the wall, 2, is provided with an inwardly directed circumferential. bead 3. Opening through the bottom edge of the cylindrical wali 2 is an arch shaped. opening 4, and at thetop of the opening, and coincident "with the vertical axis thereof, isja notch 5.

Telescoped' over and desirably permanently attached, to the upper end of the wall 2 is a circular peripherally flanged top 8, within an elliptical opening of which is fitted a similarly shaped flue thimble'9. The thimble 2 has an outwardly extending flange 10 at its upper end that overlies the top 4 and is desirably welded thereto, and at its lower end the thimble is provided with an, inwardly directed flange 11 that forms a seat for the flue that is designated, generally, by the reference numeral 12. The top 8 is shown as permanentlyfastened to the cylindricai wall 20f thehousing by a. suitable number of depressions or e ed. Qc -v 955.?

bead 3. The member, when so positioned, defines the bottom of a combustion chamber C. The member is provided with a relatively large central opening 18 that is surrounded by an upstanding cylindrical flange 19, inturned at its upper end to form a seat 20.

denotes, generally, a liquid fuel burner that is made up in most part of a U-shaped casing 26. The casing is desirably constructed of sheet metal halves having flanges 27 and 28 along their inner and outer edges, respectively, that meet in the central vertical longitudinal plane of the casing. As indicated especially in Fig. 4, the flanges are welded together along their outer edges. Butt welded to the inner branch of the U-shaped casing is a cylindrical throat member 30 that is provided with air admitting openings 31, shown as arranged in circumferential rows. The outer branch of the U-shaped casing 26 encloses what, for the present, may be termed a fuel receiving space 33, While the inner branch encloses a carbureting space 34. Between these spaces and adjacent the bottom of the easing is a vaporizing region 35. The wall of the casing that encloses the carbureting space is provided with air admitting openings 36.

Detachably applied to the lower end of the cylindrical wall 2 of the housing 1 is a circular bottom 40, having a cylindrical flange 41 that telescopes over the lower end of said wall. Frictionally engaging the inner side of the wall in the plane of the flange 41, and at spaced intervals thereabout, are spring clips 43 whose inturned lower ends 44 are welded to the bottom 40.

Slidably engaged through holes in the cylindrical wall of the housing adjacent the lower edge thereof are the parallel branches of a number (desirably three) of socalled hold-down lugs 45, each being constructed of a piece of rod of suitable diameter, and the inner ends of the branches of each lug are turned upwardly to form a stop to limit the outward movement of the lug, the lug being retractible until its central portion lies closely adjacent the flange 41 of the bottom 40. Said flange 41 is notched for the reception of the branches of the lugs when the bottom is applied to the housing. The upper edge portion of the flange 41 is cut away throughout the width of the arch shaped opening 4 of the wall 2, and said flange is provided intermediate the ends of the cutaway portion with a notch 48 that is in vertical alignment with the previously mentioned notch 5 of the wall 2. The flanges 27 and 28 of the burner casing 26 are also notched on the vertical axis of the burner casing, and when the inner branch of the burner casing is inserted through the opening 4 and the throat 30 is engaged within the flange 19 of the annular member 15, in contact with the seat 20 thereof, the notch of the flange 27 of the burner casing registers with the notch 5 of the wall 2 and, likewise, the notch of the flange 28 of said casing registers with the notch 48 of the bottom 40. Accordingly, when the bottom is in normal relation to the wall 2, the burner is firmly held in the position described, the flanges of the burner casing interlocking with the cylindrical wall and bottom of the housing in the regions of the aforesaid notches, and in a manner obvious from the construction. A closure 50 fits within the outer branch of the burner casing 26 and is permanently secured in place by welding the horizontal peripheral flange 51 of the closure to the end of said branch. The closure is shown as having a depressed peripheral portion and an elevated central portion within the latter of which is a lighting opening 52 that is normally closed by a disc-like cover 53. Said cover has spaced apertures through which the elongated shanks 54 of a wire retainer 55 extend, the lower ends of said shanks being turned outwardly for engagement with the underside of the adjacent portion of the closure 50 when the cover is lifted by means of a handle 56, formed as a ring from the central portion of the wire retainer 55. The cover is desirably provided with a peep hole 57 through which the operation of the burner may be observed.

Projecting through a hole in the closure 50 that is laterally spaced from the lighting opening 52 is the discharge end of a fuel supply conduit 60. Said discharge end, in the present instance, consists of an elbow 61, the inner end of which defines what may be referred to as the fuel feeding orifice 62.

denotes a so-called dripper wire, which term is intended to embrace any equivalent element that functions in substantially the same way as said wire. Its proximal end is extended upwardly through the orifice 62, substantially centrally of the vertical branch of the elbow 61, and the wire is shown as secured in place by having its upper end projected through a hole in the elbow and welded to the latter about said hole. In the region of the orifice, the wire is desirably offset laterally for contact with the outlet end of the elbow directly below the lateral branch of the latter. Thence the wire continues downwardly and toward the central portion of the burner casing where it terminates a suitable distance above the bottom thereof.

Included in the fuel supply conduit is the casing 68 of a conventional needlepoint valve 69, on the upstream side of which the casing has a lateral branch 70 that is adapted to be joined, by a coupling 71, to a pipe 72, that leads from a suitable source of supply, such as a tank (not shown). It may be explained that the tank is located above the level of the burner so that the fuel will feed by gravity. The pipe 72 is desirably flexible and may consist of plastic tubing. The valve casing 68 is provided with a sight opening 73 through which the feeding of the fuel may be observed when the valve 69 is open.

If desired, a window may be provided in the cylindrical wall 2 of the housing 1 through which the character of the flame that is present in the combustion chamber C may be observed. The window, in the present case, is made by cutting a rectangular opening in said wall and attaching to the wall about said opening a frame 81 between which and the portion of the wall immediately surrounding said opening is confined the marginal portion of a pane 82 of mica or the like.

The top 8 of the combustion chamber is provided with apertures 84 which act as breather holes" to prevent the establishment of a resonant condition within the combustion chamber and thereby assure quiet operation of the burner through its normal burning range.

The flue 12, hereinbefore referred to, desirably consists of a stove pipe made up of sections 85, 86 and 87 that are joined one to another in the usual way, but dilferentiating from a conventional stove pipe in that the longitudinal seam of each section is separable. As will appear from Fig. 3, the lateral edges of the sheet metal blank from which each of the sections is made, are formed for interengagement in an obvious manner for the purpose of retaining the section in tubular condition.

With the sections in such condition, they are joined together to form the flue 12, the lower end of which snugly fits within the thimble 9, in the top of the housing 1, against the flange 11.

Over the upper end of the top section 87 is telescoped the lower end of a draft diverter 90 of conventional character, excepting that it includes means for attaching guys 91 (incidentally through the medium of the diverter) to the upper end of the flue. According to the present construction, each guy 91 consists of a length of rope 92 and an insert of chain 93 adjacent the flue for the obvious purpose of protecting the rope from the heat of the flue. In the erection of the apparatus, the guys are drawn tight and fastened to suitable anchorages or stakes to hold the apparatus in an upright position.

With the apparatus assembled and set up, as illustrated in Figs. 1 and 4, it is placed in operation by first opening the fuel control valve 69 and admitting a limited amount of fuel to the burner casing 26. As this fuel is admitted, it runsdown the dripper wire 65 and accumulates in a small pool in a sump; provided by the bottom portion of the burner casing. The fuel. in this pool is" then ignited by' a' match or torch introduced through the lighting opening 52,. after the cover 53 has been lifted' from said opening. by the handle 55 until stopped by engagement of the outwardly turned lower ends of the shanks 54 with the underside ofthe closure 50*. A small fl'ame ensues, and a mixture of the resultant products of combustion and unburned fuel vapors rises from the pool, and is drawn toward the throat of the.

Ithas been found advisable, during the first few monrents following he lighting of the burner, to keep the cover 53 removed from the opening 52 as this allows. air to enter the burnercasing and sweep past the pool of fuelin the sumpso as to assist in the vaporization of the fuel. After the burner parts have become heated, however, theheat radiated therefrom is sufficient to vaporize the amount of fuel necessary to sustain combustion, and said cover" may now be replaced over the lighting opening.

As combustion continues, the burner casing becomes heated andthe pool of fuel in the sump tends to vaporize more; rapidiy until finally, when equilibrium is reached, i. e:, when the burner is operating, efficiently and satisfactorily at ornear maximum the due to a balance of vapor and air at the present valve setting, the process of combustion is found to originate in the vicinity of the primary air openings 36 and to advance to full intensity in the region of the throat openings 31, attaining completion within the combustion chamber.

During high fire operation, the burner operates with a very small pool of fuel in the sump. It is desirable that a small pool be maintained when the burner is in operation at relatively high fire for this tends toward a stabilized fire condition.

It appears that small peephol'e 57 in. the lighting cover 55 admits a limited amount of air, producing a currentthat carries; the fuel vapors from above the pool of fuel to the combustion zone during normal operation. However, insufficient air is entrained through the peephole to support combustion in the region of the fuel discharge orifice 62 As a result, this region of the burner operates atsuch a relatively low temperature that no carbonor other objectionable residue is deposited about the fuel discharge orifice, and therefore the fuel supply rate remains constant.

It might be well to explain here that, due tothe shape of the burner casing, the surface area of a poolof fuel of given volume that reposes within the sump constitutetf of the elbow portion of the casing is always. thesame, regardless of whether the apparatus is tilted perceptibly from arr upright position. Accordingly, the size of the fire, at any setting ofv the control valve 69, is. unaflectedby a tilting of theapparatus within reasonable limits.

For the purpose of explanation, the interior of. the burner. casing, may be considered as divided roughly into three. zones; the first, including the region, within the outer, branch of the U-shaped casing 26 from the top thereof, to about the center of the burner. The second Zone extends from the first zone into the inner branch of the casing to about the lower end of. the throat, member, and? the third zone continues thereabove through the throat member into the combustion chamber. During high fire operation (wherein the fuel consuming rate in an apparatus] of the size hereinbefore mentioned is approximately cc. per minute, with a heat output in the neighborhood of 30;!)00" B. t .u.-sper hour), combustion is most' intense inthe third' zone, with practically-no-com bustion occurring in the second zone and; of course, none in the first zone. When the fuel supply: is decreased to the low fire rate (3 to 6 cc. perminute with anoutput of 7,500 to 15,000 B. t. ufsper hour) combustion is initiated and practically completed in the second or intermediate zone. Under this present low fire condition, all the necessary primary and secondary air enters throughthe openings 36 in the innerbranch of" the burner casingbelow the throat member. Even at this reduced fire there is no tendency for the flame to flash back to the fuel discharge orifice 6 2, and no combustion occurs in the-region thereof or, in other words, in the first zone. This Ina-y be accounted for by the fact that the burner partsin the immediate vicinity of the orifice are relatively cool, as before stated, and therefore have little tendencytogenerate and ignite vapor even thoughsaid parts be wetted'by the fuel.

Itis manifest from the foregoing that the burner, proper, operates ata lower temperature during high fire, when combustion occurs withinv and is confined to the third zone, i. e. the region of the throatmember and the combustion chamber, than it does atlow fire, when combustion islargely confined to the secondzone, or in other words tothe interior of the inner branch of theburner casing;

After the apparatus has been placed in operation, thesize of the fireis, of course, determined by the amount of fuel fed, and this, in turn, is controlled by adjusting;- the valve 69 and observing the descent of the fuel through the valve casing 68 past the sight opening 73 therein. For minimum fire, inan apparatus of approximately the size referredto, the valve 69 is adjusted toeffect a feedof about two drops of fuelper second. Feed for maximum fire is attained when the valve has been opened sufliciently tocause the drops-to merge into a continuous: stream. At minimum tire, with combustion occurring well down in the burner casing, the burner parts, including' the lower portion (probably two-thirds) of the dripper wire; will be heated to a relatively high degree, the temperature of said portion of the wire exceeding the boiling point of the fuel. Under these conditions, the fuel will drain down the wire in a thin stream until it reaches the highlyheated lower portion thereof when it will flash into vapor and' join the air entering through the lower holes of the burner casing, producing therewith the volume of combustible mixture responsible for low fire. It is apparent that, during this phase, the burner will operate with a dry sump; and because of the presence of the fuel onthe upper portion of the dripper wire, and the drift of air through the outer branch of the casing as previously explained, the parts adjacent the fuel feeding orifice 62 will remain relatively cool, wherefore there will be no likelihood of combustion occurring in the i'mmediatevicin-ity of said orifice.

During high fire operation, when the burner parts, including the dripper wire- 65-, are relatively cool as a result of their remoteness from the flame which is now Well up within; the throat of the burner and in the combustion chamber, the fuel willflow in a continuous stream ofliberal volume down the full length of the dripper wire, further contributing to the wires coolness, and descend therefrom into the sump, with the result that apool is maintained, from the surface of which the fuel is-vaporized by heat radiated downwardly from the flame and the burner parts surrounding it. The vapor thus generated' mixes with the so-called primary air that enters through the holes of the burner casing below the throat, producinga rich mixture that is rendered combustible by secondary air that enters through the openings 31 of the throat member 30.

While I have described only low and high fire operations, it will be obvious that, at any intermediate stage, the respective characteristics of these two extreme conditions proportionately change, the characteristics of one modifying those of the other, according to the setting of the control valve.

When the apparatus is to be transported or stored, it may be disassembled in an obvious manner, after releasing the guys 91 and removing the stakes from the holddown lugs 45. All parts but the housing 1 may now be arranged in compact condition in the latter, as illustrated in Figs. 2 and 3. After removing the draft diverter 90 from the end of the flue section 87, said section and those designated 85 and 86 are opened along their sides by disengaging their hooked edges. The sections may now be expanded and inserted in the housing along one side thereof, and the draft diverter, guys, flexible pipe 72, and other loose parts may be placed in the housing alongside the flue sections. The burner 25 is then arranged in the lower portion of the housing with the throat member accommodated by the opening 14. The annular member 15 may next be placed within the open end of the housing, as illustrated in Fig. 2, and the bottom 49 applied,

delivery means having a fuel discharge orifice that opens into the top portion of the first branch of said casing, said first branch being provided with means in the vicinity of said orifice for admitting air in limited quantity to the casing and being otherwise closed at its upper end, the

lower central portion of the casing being characterized by a bottom that curves upwardly in all directions thereby providing a sump for a pool of fuel whose surface will remain unchanged in area notwithstanding perceptible tilting of the casing from an upright position, the second branch of the casing terminating at its upper end in a perforated throat and having therebelow means for admitting air to the casing.

2. A liquid fuel burner comprising the combination and arrangement of parts defined by claim 1, and a dripper wire having its upper end in fuel receiving relation to said orifice and its lower end in close proximity to and directly above the sump.

3. In a liquid fuel burner, a substantially U-shaped casing in the form of a tubular elbow of constant radius and uniform circular cross section from end to end, the casing including two upstanding branches that are spaced apart a distance less than their diameter, the first branch enclosing a fuel receiving space and the second branch enclosing a carbureting space, the casing providing, by reason of its elbow formation, a fuel sump extending below said spaces, means for delivering liquid fuel to the receiving space, the second branch having perforations located above the sump for admitting combustion air to the carbureting space, and a dripper wire extending from the liquid fuel delivering means at the point of fuel discharge thereof toward and in proximity to and directly above the fuel sump.

4. In heating apparatus of the class described, a vertical housing, a wall disposed horizontally therein and defining the top of a burner compartment, said wall being provided with a relatively large opening, a substantially U-shaped burner casing including relatively short upstanding branches, the first of said branches being substantially closed at its upper end, means for delivering liquid fuel to the upper portion of said first branch, a fuel conveying element leading therefrom to the central bottom portion of the burner casing, the second branch being open at its upper end and joined to said wall about the aforesaid opening, said second branch being provided with means for admitting air thereto.

5. Heating apparatus comprising a vertically disposed cylindrical housing having an opening in one side adjacent the bottom thereof, an annular member within and disposed across the housing above said opening and defining the top of a burner compartment, a U-shaped burner casing including relatively short upstanding branches, said casing being arranged with its central portion disposed within the side opening of the housing with the first branch thereof outside the housing and the second branch within the housing with its upper end joined to said annular member about the opening therein, the last mentioned branch having means for admitting air thereto, the first branch being substantially closed at its upper end, and means for delivering liquid fuel to the first branch in the region of its upper end.

6. In heating apparatus of the class described, the combination of an elongated vertically disposed housing having a relatively large notch in one side thereof that opens through its lower end, a member within and disposed across the housing above said notch, said member defining the top of a burner compartment and having a relatively large opening, a substantially U-shaped burner casing including relatively short upstanding branches, the burner casing being disposed within said notch of the housing with one branch joined to the aforesaid member about the opening of said member, said branch having means for admitting air thereto, the other branch being disposed outside the housing and being substantially closed at its upper end, means for delivering liquid fuel to the last mentioned branch adjacent the upper end thereof, and a bottom applied to the lower end of the housing, the burner casing having parts interengaging with parts of the housing and said bottom for maintaining the burner casing in fixed relation to the housing.

7. Heating apparatus comprising an elongated vertically disposed cylindrical housing, the housing being provided with a relatively large arch like notch that opens through the lower end of the housing, stop means on the interior of the housing above the top of said notch, an annular member having a relatively large opening and adapted to be inserted upwardly into the lower end of the housing and engaged with said stop means thereby to define the top of a burner compartment, a bottom detachably applied to the lower end of the housing, a U-shaped burner casing including relatively short upstanding branches, said casing being arranged with its central portion within the aforesaid notch of the housing with its inner branch joined to said annular member about the opening thereof, said inner branch having means for admitting air thereto, means substantially closing the upper end of the outer branch of the burner casing, and means for delivering liquid fuel to said outer branch adjacent the upper end thereof, the burner casing having means interengaged with the housing and bottom in such manner as to be retained in operative position with respect thereto.

8. A knock-down heating apparatus comprising an elongated vertically disposed housing, the housing being provided with a relatively large arch-like notch that opens through the lower end of the housing, stop means on the interior of the housing above the top of said notch, an annular member having a relatively large opening and adapted to be inserted upwardly into the lower end of the housing and engaged with said stop means, a top for the housing, the housing being provided with a flue connection, a collapsible flue separately connected thereto, a bottom detachably applied to the lower end of the housing, a U-shaped burner casing including relatively short upstanding branches, said casing being adapted to be arranged with its central portion within the aforesaid notch of the housing and with its inner branch engaged with the annular member about the opening thereof, the burner casing having means adapted to be interengaged with the housing and bottom in such manner as to be removably retained in operative position thereby and serving, when in such po sition, to maintain the annular member adjacent the aforesaid stop means, the foregoing elements being so related in size that when disassembled all but the housing are capable of being arranged in compact form within the housing with the bottom applied to the latter.

References Cited in the file of this patent UNITED STATES PATENTS

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