US2568487A - Multiple tube radiator forced circulation air heating furnace - Google Patents

Description

P 1951 A. B. CARSWELL 2,568,487

MULTIPLE TUBE RADIATOR FORCED CIRCULATION AIR HEATING FURNACE v Filed May 13, 1948 4 Sheets-Sheet l Inventor ALLAH BRYSON CARSWELL Attorney Sept. 18, 1951 4 Sheets-Sheet 2 Filed May 13, 1948 MVN 4 Invehtor ALLAH BRYSON cAnwELL Sept. 18, 1951 A. B. CARSWELL 5 4 MULTIPLE TUBE RADIATOR FORCED CIRCULATION AIR HEATING FURNACE Filed May 13, 1948 4 Sheets-Sheet 5 Inventor I ALLAH masen cmswELL' Atta rny Septo 1951 A. B. CARSWELL ,568,487

MULTIPLE TUBE RADIATOR FORCED CIRCULATION AIR HEATING FURNACE Filed May 15, 1948 4 Sheets-Sheet 4 Inventor ALLAH BRYSO CABSWELL v Attorney Patented Sept. 18, 1951 -u-N rz ?STAT ES FAT OFFICE IMULTIPLE TUBE RADIATOR FORCED CIR- CULATION AIR :HEATING FURNACE AllaniBrysonCarswell, otta vafontario; Canada I :Application May 13, 1948,*Seriol` Nermin-89 e 6 Claims.

*furnacemand` especially .to one having increased heat transfer areas and amore eflicient routing of the poducts of combustion; from the\ fire pot tothe. emergingn smoke pipe.

Among the principal objects ofrtheninvention ara t provide.anovct furnacastructure that will yieldvup ahighenpercentage of thetotal heat of combuston, enable t the.extraction of substantiarl yuallt the:` heat, fromtheproducts. of combustion reducingthe temperature of ,the output of normally-Very: hotfiflua lgases -to, near room .temperatura; andtim whichztthe essential. parts of the furnace are so arrangedzas to afiTord ready, access for cleaning-and seryicing rthattthe i\ unit may be eas ly maintained a in %condition for speak performance e I t A t further. chiesto&thecinvention is to provide a heat-Jtranserring bank ofrfinned smoke i tubes removably :mounted inthe furnace to allow of replacement as%single-unit.

It is::further withinthe province of the invention; heroin tdisclosed .to provide ta" hot air, urnace ofa generailysimplified and improved design, substantial andrdurabl ;structure and enhanced operatmgefiiciency andneconomy that is .capable of manufacturen at; relativelytreasonaable i cost.

the accermalish-rnent` of these` and i related objectsasshall becomezapparent as the: description proceeds, the invention residesintheu constmcton, :combination and? arrangement of `parts as-sha-11 :bes hereinafter a more? fully described, illustrated &in {the ,accompanyng drawings,` and tpointed-outintheclaims hereunto appended.

3 They invention wi11 bevbest `understoodand can bemcre clearly described whenreference is had tothe-drawings\ forming a :part `:of this` disclosure wherein like characters indicate like :parts thrc ghout the sewerakviews.

iFigunesr-and 6 are details oftheheat radating finitbeingzana-elevation and section-respectively.

, rwithranelongated rectangular -casing l a fire potrzand-- dome 3 are arrangedxsomewhat-forwardly of a central position. Across the front of the dome and in open communication with it is 2 attransversehorizontal `chamher 4. Across .the rearof the furnace, level with the dome: and front ;chamber `.4, i and spaced somewhat. behind therearof'the `dome is ,a smoke outlet manifold chambex. from which the usual smoke-1 11 66 emerges. Jtoining the front chamber 4 .and the rear smoke manifold are two banksof finned tubes '[oneon either side of the fire pot .dome.3. Just totherearof this dome a vertical transverse bulkhead or, partitiona divides. the furnace cast ing I into fore and aft sections with halftor more of .the i tube banks lying in the forward part. `;..It w i1l=be seen thetopof the casing l is open as` this instant invention is `not concerned with either thesource or.eventual distribution of the air. However,`theipartition 8 marks .the division betweenther cold air'` in1et 94 and the hot air outlet m. t n

&Below therearsmoke manii'old 5 and the after part ..oi` the tubebanks 1 the air,passageww` or route H, passes through filter pads !2 then `enters` oppositecsidesc of a motor driven fan l3ina fannhousing [4 inthenlowerurear of the iurnace casingithenceunder the, partition 8 into the forward section of'the furnace where it encircles the. fire `potand; dome and rises throughthe bankswof i finned smoke tubes 1. tor pass out through the cutlet |0`in` the open top of the forward section.

Though myrfurnacetmay be-adapted to any kind of fuelorfiring, Figure 1 shows a guntype oil burner |4 inarclosed off compartment the lower 'front protected n by -a removable louvered frontuclosurel5. The upper. part" of the .walls and` slopingpart of the top of .the. front section of the casing. is insulated asindicated at !6 and maddition.- to :a r door !1 `affording access to the fire. pot,. dome .andfnonttransverse chamber' 4,' a. hingingbafle. guard I a. is .Suspended.`

Ereferably the.entire furnace is of a all-welded steel construction i. and .the outer ar-rengaging surfaces `of `the dome 3 -and front chamber 4 havetradiatingnvanes ,or ribs !9 that serve alsoto strengthen the .deine n structure.

Thebanks of tubes"1 areeach formed asacomplete .and .removable unit. The multitude. of small, .relatively thin, equally spaced` paralll tubes'laarecarried by three panels lb, 'ic and. Td respectively and providedwth fireproof, air tight gasketsiare removably Secured to fianges 20 at thei front compartment, the partition 8 and the innern. walleofjthe reansmoke manifoldj.` On the' back ofthe casing"|,` in line with each' bank of tubes 'I is a clean out door 2l of sufiicient size to allow for the installation and removal of a complete bank. spaced longitudinally along the banks of tubes are thin, vertical, transversely extending sheet metal radiating fins 'le having perforations 'If to pass the fins, and the perforations fianged as at Tg. The fin perforations have a tight, frictional engagement with the tubes so the expanding of the metal on heating increases the conductivity of the connection. Like all other joints in this furnace, the tubes are welded to the panels, especially 'lb and 1d, although the partition engaging panel 'Ic may be an enlarged fin.

The cross sectional area of the tubes Ta is such as to offer no obstruction to the flow of the products of combustion therethrough even with the greater surface frictional engagement encountered and being small and finned and of considerable length the gases fiowing therethrough are able to give up almost completely of their heat units before emerging into the rear smoke manifold 5. The down draft of incoming cold air entering 'through the open top 9 of the rear section passes over the rear ends of the already partly cooled banks of tubes Ta, and is partially warmed while taking up most of the remaining heat of the fiue gases in the tube banks. Thus the current ofair is raised to a higher temperature than would otherwise be the case by contact with the ribbed fire box dome and the very hot front sections of the tube banks before leaving the front section furnace outlet o.

From the foregoing description taken in connection with the accompanying drawings, it will be manifest that an efficient and economical furnaceisprovided that will fulfill all the necessary requirements of such a device, but as many changes could be made in the above description andpmanv apparently widely different embodiments of the invention may be constructed within the scope of the appended claims, without departing from the spirit or scope thereof, it is intended that all matters contained in the said acompanying specification and drawings shall be interpreted as illustrative and not in a limitative or restrictive sense;

. Having thus described the invention, what I claim as new and desire to secure by Letters Paten s: i, 1 A furnace comprising a fire pot fueled from the front and dome surmounting the same, a transversely disposed chamber forward of said dome in communication therewith, a transversely disposed outlet manifold to the rear of said dome, removable banks of horizontal tubes on each side of said dome connecting said chamber and manifold and a, casing therefor with an inlet at the upper rear portion and an outlet at the upper front portion thereof and having an air passageway therethrough beginning over the rear of said banks of tubes and subsequently crossing the forward ends of said banks of tubes.

2. A furnace comprising an outer casing, a front fueled fire pot and surmounting dome therein forwardly of centre, a transversely disposed chamber in front of said dome centrally open thereto, a transversely disposed outlet manifold in the rear of said casing and spaced a distance back of said dome, a unitary removable bank of heat transfer tubes on each side of said dome connecting said chamber and said manifold, a vertical transverse partition in said casing extending across said casing from side to side and downwardly from the top to a point spaced above the bottom thereof and disposed to the rear of said dome and a fan circulating air down the back of said partition and up the front; said casing having air inlet and outlet openings disposed respectively to the rear and front of said partiton and both located above the lower edge thereof.

3. The combination with the structure set forth in claim 2, of a clean out door in the back of said casing in line with each of said banks of tubes and wherein said banks of tubes are each removable long itudinally through said doors as a in claim 2, wherein a heat transferring bank of tubes consists of a plurality of elongated horizontal tubes, radiating fins spaced therealong, formed of sheet metal and perforated to pass the many tubes of the bank, the perforations being of a size and flanged to have tight fltting engagement with the tubes.

6. An all-welded steel furnace comprising an outer shell or casing open to the top, a vertical. transverse partition dividing said casing longitudinally into front and rear sections with an opening through the bottom thereof, an air circulating fan directed forwardly through said partition opening so a current of air is drawn into the casing through the open top of the rear section, passed under said partition and expelled through the open top of the front section, a fire pot and dome in said casing forwardly of said partition, a transversely disposed chamber across the front of and in communication with said dome being open thereto throughout its height for the full width of said dome, a transversely disposed outlet manifold in the rear of said casing and spaced a distance back of said partition and a bank of finned heat transfer tubes on each side of said dome connecting said front chamber and said rear manifold, said banks being longitudinally removable through the back of said casing and sealed where 'they fasten to said chamber and manifold with fireproof air-tight gaskets.

ALLAN BRYSON CARSWELL.

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

UNITED STATES PATENTS

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