US2651514A

US2651514A - Apparatus for producing a heated gaseous medium

Info

Publication number: US2651514A
Application number: US133103A
Authority: US
Inventors: Rallston M Sherman
Original assignee: Silent Glow Oil Burner Corp
Current assignee: Silent Glow Oil Burner Corp
Priority date: 1949-12-15
Filing date: 1949-12-15
Publication date: 1953-09-08
Anticipated expiration: 1970-09-08

Description

Sept. 8, 1953 R. M. SHERMAN APPARATUS FOR PRODUCING A HEATED GAsEoUs MEDIUM Patented Sept. 8, 1953 APPARATUS-Fon PRODUCING A HEATED.

v GAsEoUs MEDiUM Rallston M. Sherman, Glastonbury, Conn., as-

signor to The Silent Glow Oil Burner Corpora-l tion, Hartford, Conn., a corporation of Connecticut Application December 15, 1949,- vSerial No. 133,103

4 claims. (o1. 263-4-19) My invention relates to the production of heated gaseous mediums, the heat of which is derived by burning uid fuel, so as to enable'the heat generated by combustion of such fuel to be conveyed to a more or less distant place.

The invention, which has among its objects the production of a heated gaseous medium While effecting proper combustion of the fuel, will be best understood'from the following description when read in the light of the Vaccompanying drawing of an embodiment of the invention, while the scope of the invention will be more particularly pointed out in the appended claims.

- Thedrawing is an elevation, with parts broken away and parts in section, of a form of the invention in which the `fluid. fuel employed is in the form of fuel oil. f

In the form ofthe invention illustrated by the drawing there is providedan inner or combustionV chamber I having the cylindrical lateral wall 3 and end walls 5 and 1. The cylindrical wall is shown as provided withsmall relatively closely spaced perforations 9. `These perforations are distributed over the entire cylindrical surface, while, as shown, the end Walls are imperforate except for the central opening II formed in the end walll 5. However, 'if' desired, the perforations 9 also may extend over the end wall 'I. i I

The opening II of the end wall 5 receives the discharge end section I3 of an air conduit I5 comprising an intermediate section I'I carrying at one end the section I3 and communicating at its opposite end with a section I9 formingpart of a conventional gun-type "oil burner'.VY This burnercomprises a casing portion 2|v containing an Velectric `motor driven fanvor blower 23 for forcing atmospheric air ythrough the air-conduit I5-Ainto kthe combustion chamber I, Vthe amount of air discharged by the fan beingy regulatedfin the usual manner by adjustable Vshutters (not shown) positioned at one end of such casing portion, vwhich-'shutters controlthe size of the air intake to the fan. -As in the conventional vguntype oil burner, the pump 25, driven by the same Inotor as the fan, draws fueloil` fromY the tank 21 -and discharges it under pressure into la pipe 23 in communication with an oil conduit orpipe 33 positioned' axially of the air conduit I5, thev pipe 33 having at-its end adjacent the combustion chamber I a spray nozzle 35 for atomizing orV comminuting the -fuel ',oil. lThe fuel oil so atomized enters *the combustion'chamber I admixed with the air discharging Afrom the ad-j -z jacent end of the air conduit I5. The nozzle is so designed as to secure the desired pattern of flame produced by the mixture when it is burned in the combustion chamber I and the desired amount of oil supplied the combustion chamber. Preferably positioned in the section I3 of -thefair conduit l5 is a circunriferentialv series of vanes 31 for causing a whirling action of the air discharged into the combustion chamber I from the conduit so Aas thoroughly to mix the air with the atomized oil. The burner, as shown, `is provided with an ignition spark device 39 for igniting the mixture, and preferably is provided with the usual controls for governing the operation of the burner in accordance with the'temperature conditions of the space to be heated vby the gaseous medium produced by the-apparatus.` Surrounding the drum orfcombustion chamber l with its Walls in spacedvrelation vthereto is shown an outer'drum or chamber 4I having the lateral cylindrical wall 43 and opposite.

end walls

45 and 41, the end-wall 45l being provided with an opening 49 to permit passage therethrough of the section I1 of the air conduit I5, While the end wall `41 has a central opening withwhich communicates a conduit `5I for conducting the heating medium produced by the apparatus to the space to be heated as, for example, to the heating flues of a tobacco or other crop storage or cropvcuring barn. Y y As shown, the section I'I `of the air'conduit I5 is provided with perforations 53 forming an opening which permits the bulk of the air forced through the air conduit I5`by'the ian 23 to enter the space between the inner and outei1 drums or chambers I and 4I for passage therethrough and discharge into the conduit 5I. This -air is heated by contact with and radiation from the hot walls of the inner or combustion chamber` I, and mixes with the gaseous products of combustion discharged into such space from the combustion chamber through the perforationsfg for further augmenting the heat of the gaseous medium thus produced. In respect to the amount of oil burned in the combustion chamber I, the fan 23 is of oversize because of the bulkof the air forced by it discharging through'the perforations 53. Preferably the amount of air discharged through these perforations will be such as to maintain the hottest portions of the walls of the outer chamber 4I and conduit 5I at as high a temperature as possible, say 650 F., but without causing them at any point to glow so as to avoid creation of a re hazard. Ordinarily thisY will` necessitate discharge through the perforations of from about 70 to 80% of the air supplied by the fan, the remainder of the air discharging into the combustion chamber I in the form of air admixed with the atomized oil, with the result that a very large voume of :heated gaseous -medium is produced by `the apparatus: tor discharge through the conduit 5 l.

The combination chamber i preferably is identical with that described in applicants pending application Serial Number 115,090, nled September 10, 1949, and preferably the burner is operated in identically the same'wayf. As in said application, complete combustion of the oil may be secured by having' in the combustion chamber a flame of such pattern that it does not contact with the walls of said chamber; the ycil being burned at such rate that the perforated area of the chamber throughout its extent is heated to incadenscenceY say from 900 to 1500" E. Acomplete combustion will result inV the gaseous; medium produced by the presentappa containing. no innammable products, will render it odorless smokeless, for :with .combustion the. gaseous combustion vrmoducts escaping through the perforations e will consist Wholly of carbon dioxide, oxygen and nitrugen,

Pceferabdy the space between the two here t It and. the cross-sectional area or the conduit 5l' are such,l with relation tothe amount or. suppiied. that and. the amounts or air the chamber :l and the senera'tedc thatthspressme inthe; chamber l is very slightlyin excess of that. in the spacev between. the two chambers so as to prevent entranceoi air from. .such space into the chamber l through the pe'norationsf 9o Were .such :air permitted to enter the chamber l through the perfcrati'onsg. or were the name within that chamber' permitted: to contact wuth its .perforated wall portions so that mrburned' products of thevaporized--oil would escape through. said perforations, confiplete combustion of the oil would not occur. Under any ordinary conditions the difference in pressures mentioned need amount only from about 0.0008 to 0.006 inch of water. The pressure in the space between the two chambers, however, can be such as isf reu,-V uisite to forcethe heated medium to the place where it is to be used, or an exhaustfan or blower associatedwit-h the conduit 5i may be employed fer: that purpose, such ian or blower when ernployed, of. course, acting. to draw the heated :medium from thespace between the two chambersfso as to tend to reduce the pressure in that spacew and that. way act as well asthe or blower -23 to determi-ne the amount of air passed through such space and. therefore theactual pres sure maintained in it.,

As further pointed out in the above mentioned applicatiom to secure compl-ete combustion the perforations i)I should not exceed approximately 0.15A inch in diameter or otherwisehave a cross--V sectional area greater than that.` approximately represented by a circular perfo-ration, of suchdiameter,- the perforations preferably being as small as canA be economically produced. Furthermore, tosecure complete combustion` within the combustion.chamber the total areapresented by the perforations per square inchv of perforated surface should be from approximately 0.05 to I 0.14 square inch, while the. sheet metal constituting the perforated portionV of' the combustion chamber should'v be as thin as structural requirements will permit, refractory sheet metal, such as stainless steel, about sa inch thick giving's'atisfactory results in most situations. Furthermore, as pointed out in said application, to secure combustion the cubical contents of the combustion chamber should be from approximately 2300 to 4000 cubic inches per gallon of oil burned therein per' hour, the total perforated 'surface of the chamber expressed in -squareinches from 15 to 35% of the arithmetical value of the cubical contents of the chamber expressed in cubic inches.

Various 'kinds oi oils may be burned, satisfactory results having been secured with ordinary serrurier@ial.gasoil-'iriaY kerosene, and all grades of fuel-l-elrrptesoaled No. 3 fuel oil.

Wh'err a cylindrical combustion chamber is employed the relation between its diameter and its length is not critical, satisfactory results having been secured where the length of the chamber is from 10'0`to 400% of its diameter. Examples of these cylindrical combustion chambers are those 15 inches tn diameter and. y118 inches lone,\.22 inches in diameterrand 24 inches ion-g, .22 .inches diameter and 36 .inches long. arrd26` inches in diameter and 30 inches long.. Other .proportions between the .length and. diameter of the combustion chamber however may beemplbyed, andsatisfactory results have been secured with combustion` chambers the lengths-*of which are less than their diameters, for. example, a r-:ombustionl 'chamber 22 inches in 'diameter and 18 inches long.

The amount vof air admi-ized with the atomized oil may be that commonly employed in connection with domestic oil burners, ,preferably an amount of air which will give a bright orange llame. However, lesser amounts or air may be employed dow-nto that vwhich will `give: a blue name. It is advisable, as' inthe ordinary case of combustion apparatus, to keep' the excess amount of air admixed with the atomized oil at .a minimum consistent with .securing` satisfactory operation, as otherwisethe temperature or `the combustion products will be unduly decreased. In accordance with common practice this amount of air should vbe suchas .to `give a rather small amount of excess Y oxygenY in :respect to the amount thereof which will stoiehiometrically secure complete combustion, namely; from about 8 to 15 excess oxygen, ,preferably from about l0 tol2i%.

It will be understood that within the scope' of the appended claims wide deviation-s may be madeirom the formof the invention described without departing: .from the. spi-rit of the invention.

l'. Apparatus for producing a heatedv gaseous medium comprising walls forming a combustiony chamber having an opening, at least a portion of which Walls is .formed withV a multitude of spaced small' perforations other than said opening, which perforations constitute substantially the. sole means of escape of combustionproducts from said. chamber, means for heating said. walls comprising burner means for entering into said chamber through said opening a blast consisting of nuid fuel mixed with` requisite air for supportmg substantially com-plete combustion of such fuel -in said chamber, which burner means constitutes substantially the sole means for supe pl-ying air to said. chamber, that air being con tained in said mixture so. supplied said. chamber, walls at the `exterior of said. combustion cham# ber forming with said combustion chamber a second chamber with whichsaid perforations. directly communicate for discharging combustion products from said combustion chamber into said tact with said perforated wall portion of said" combustion chamber and in such amounts as to maintain a pressure in said second chamber less than that maintained in said combustion chamber by the blast of mixture entered into it and combustion of said mixture therein, whereby to heat the air so passed and mix it with said combustion products to form the heated gaseous y medium while preventing ilow of air from said second chamber to said combustion clhamber through said perforations.

2. Apparatus for producing a heated gaseous medium comprising walls forming a combustion chamber having lateral and end walls, which lateral Walls are formed with a multitude of spaced small perforations constituting substantially the sole means of discharge of combustion products from such chamber, walls in opposed spaced relation to the first mentioned Walls forming an outer chamber having a discharge opening, into which outer chamber said perforations directly open for discharging into said outer chamber products of combustion from said combustion chamber, burner means for entering into said combustion chamber through one of its end walls a blast directed toward its opposite end wall consisting of fuel oil mixed with requisite air for supporting substantially complete combustion of such fuel in said chamber, which burner means comprises a fuel oil conduit and an air conduit and means for supplying said conduits with oil and air respectively, under pressure for forming said blast, the fuel oil conduit having at its discharge end lan oil atomizing nozzle adapted to discharge into said combustion chamber a spray y of oil of such shape as to produce a flame of such pattern in said combustion chamber that it is in out of contacting relation to the walls of said combustion chamber, said air conduit also having an outlet for discharging air into said outer chamber for ow therethrough to the discharge opening of said outer chamber in contact with the walls of said combustion chamber and in such amounts as to maintain a pressure in said outer chamber which is less than the pressure maintained in said combustion chamber by said blast of mixture entered into said combustion chamber land combustion of said mixture therein whereby to prevent ow of air through said perforations into said combustion chamber.

3. Apparatus for producing a heated gaseous medium comprising walls forming a combustion chamber having lateral and end Walls, which lateral walls are formed with a multitude of spaced small perforations constituting substantially the sole means of discharge of combustion products from such chamber, walls in opposed spaced relation to the iirst mentioned walls forming an outer chamber having a discharge opening, into which outer chamber said perforations directly open for discharging into said outer chamber products of combustion from said combustion chamber, burner means for entering into said combustion chamber a blast consisting of fuel oil mixed with requisite air for supporting substantially complete combustion of such fuel in said chamber, which burner means constitutes substantially the sole means for supplying air to said combustion chamber, that air being contained in said mixture, and comprises a fuel pump and an air blower, connections for entering air from said blower into said combustion chamber through one of its end Walls and directing it toward its opposite end wall, an oil atomizing nozzle supplied by said fuel pump for entering a spray of o-il into said combustion chamber adjacent that end wall of said chamber through which the air is entered, which nozzle is so positioned as to mix such spray with the air being so entered and is adapted to form an oil spray of such shape as will produce a ame of such pattern in said combustion chamber that it is in out of contacting relation to the walls of such chamber, and air admission means for supplying air from said blower to said outer chamber for ilow therethrough to the discharge opening of said outer chamber in contact with the walls of said combustion chamber and in such amounts as to maintain a pressure in said outer chamber which is less than the pressure maintained in said combustion chamber by said blast of mixture entered into said combustion chamber and combustion of said mixture therein whereby to prevent iiow of air through said perforations into said combustion chamber.

4. Apparatus according to claim 3 in which the end wall of the combustion chamber opposite the end wall thereof through which the air is entered into said chamber also is formed with a multitude of spaced small perforations, which perforations and those of the lateral Walls of said chamber constitute substantially the sole means of discharge of combustion products from said chamber.

RALLSTON M. SHERMAN.

References Cited in the le 0f this patent UNITED STATES PATENTS Number Name Date 1,650,342 Good Nov. 22, 1927 2,072,731 Crosby Mar. 2, 1937 2,225,775 Garrett Dec. 24, 1940 2,422,213 Smith June 17, 1947 2,445,466 Arnhym July 20, 1948 2,446,059 Peterson et al July 27, 1948 2,531,810 Fyffe Nov. 28, 1950 2,538,953 Yates et al Jan. 23, 1951