US2335098A - Orchard heater - Google Patents

Description

Nov. 23, 1943. G. ANDERSON ORCHARD HEATER Filed March 20, 1940 5 Sheets-Sheet l iii G.ANDERSON ORCHARD HEATER Filed March 20, 1940 3 Sheets-Sheet 2 Nov. 23, 1943. ANDERSON 2,335,098

ORCHARD HEATER Filed March 20, 1940 3 Sheets-Sheet 3 Patented Nov. 23, 1943 UNITED STATES PATENT OFFICE ORCHARD HEATER George Anderson, Chicago, 111.

Application March 20, 1940, Serial No. 324,905

7 Claims.

1 This invention relates'to the general art of orchard heaters, which are devices in the nature of small stoves that are set on the ground between rows of trees or bushes on nights when the temperature threatens to fall to or below the freezing or frost point, and are fired to raise the temperature of the air in the orchard sufficiently to prevent damage to buds, blossoms and green fruit.

These devices usually burn a low grade of oil, and, of course, give off considerable smoke. Early types of these heaters, commonly known as smudge pots, were very crude, consisting of a pot resting on'the ground and containing a body of oil requiring frequent replenishment as it was burned, and a stack or flue above the pot for conducting off the products of combustion. The stacks or fiues were of various heights, depending on the height of the trees or bushes served by the heaters; and between the upper end of the pot and the lower end of the stack 01' flue were openings for the admission of air to support combustion and mingle with the .hot products of combustion, such admixture of air also serving to somewhat thin the smoke and increase the volume and temper the heat of the gases issuing from the top of the stack.

Later developments of these orchard heaters have been mainly in the directions of reducing the smokiness, which is harmful to the fruit; improving the burners to more efliciently utilize the fuel; eifectinga wider dispersion of the heat given off and thus reducing the number of heaters required for a given area; and adapting the heaters to variations in effective height so that they mayserve either low growing vegetation such as berry bushes, or higher growing vegetation such as the citrus bearing trees.-

Among these later developments, is a type of combustion chamber or burner known as the "drip feed, wherein the liquid fuel is delivered in constant small volume to the bottom of the combustion chamber from an oil tank or reservoir, the rate of delivery being substantially equal to the rate of consumption, so that the combustion chamber is constantly filled with flame, and the combustion of the fuel is more perfect, and less carbon and asphaltic residue is deposited on the walls of the combustion chamber and flue. In one known form of heater ofthis drip feed type, the oil tank or reservoir is located on the ground alongside the combustion chamber; and the oil, controlled by a manually regulable valve, flows down a low inclined open top trough from the oil tank onto the bottom wall of the combustion chamber, where it is burned.

The heater of my present invention is of the drip feed type; and among the objects of the invention are: to provide an improved structure by which a fraction of the heat generated is imparted to the oil in the fuel tank, rendering such oil more free flowing; to provide an improved structure by which preheated secondary air is drawn into and commingled with the hot gases rising from the combustion chamber; to provide improvements in the structure of the combustion chamber by which overheating of its bottom wall is prevented, the inflowing oil is uniformly spread as a thin film over the bottom wall, and cracking of the oil is prevented, and the combustion chamber is both anchored in the ground and strongly supported against lateral displacement; to provide an improved hood structure between the lower end of the flue and the top of the combustion chamber by which both the products of combustion and primary air entrained thereby are sent up the flue; to provide a simple means for varying the height of the flue to suit the character of the crop served by the heater; to provide an improved automatic fan for distributing the heated gases rising from the flue or flue extension; to provide an improved fuel feed of the barometric feed type by which atmospheric pressure alone, and not atmospheric pressure plus the weight of the column of liquid in the fuel tank, is the impelling force of the fuel entering the combustion chamber; and, generally, to improve the efiiciency of orchard heaters of the type described.

Still other objects and attendant advantages of the invention will be apparent to persons skilled in the art from the following detailed description of practical embodiments thereof illus-' tra'ted in the accompanying drawings, in which- Fig, l is a vertical axial section through one form of the'heater.

Fig. 2 is a top plan View of the pan-shaped combustion chamber.

Fig. 3 is a vertical section of the combustion chamber, taken on the line 3-3 of Fig. 1.

Fig. 4 is a detail View, mainly in vertical section on the line 4-4 of Fig.. 1, of an automatic fan and its mounting for dispersing the heated gases rising from the stack or flue of the heater.

Fig. 5 is a fragmentary side elevation of the main hood located between the upper end of the combustion chamber and the lower end of the superposed flue, showing a lighting opening and closure therefor.

Fig. 6 is a view similar to Fig. 1, but showing the addition to the structure of Fig. 1 of a secondary air-draft flue encircling the main smoke flue with clearance and extending above the top of the smoke flue for introducing preheated secondary air to the products of combustion and reducing smoke.

Fig. 7 is a view similar to Fig. 1, showing an extension flue mounted on the upper end of the smoke flue to .increase th height of the latter, and open at its lower end to both :the smoke flue and the atmosphere for entraining air into the products of combustion and reducing smoke.

Fig. 8 is a top plan view, viewed on the line 88 of Fig. '1, of a ring by which the oil tank is supported on the'hcod which overlies the combustion chamber, which ring permits the entrainment of air into and through the annular space between the smoke flue and the fuel tank. Fig. 9 is a transverse section, taken on the line 9-';9 .of :Fig. 18..

10iis1a'yiew similar "to .Eig. :6, but illustratin What :1 term :a :bammetric feed of .the ."fuel from :thezfuel tank :to the combustion chamber. 'iliescribingrfirsttthc form :of :theinvention illustrated in .Figs. :1 1.110 inclusive, :LZ designates "a p.an;sha:ped combustion chamber that is preferably of :castmetal'and equipped on its underside with :ancentral depending -;prong :13 adapted to bfigfQICBd into the ground to prevent accidental lateral displacement of -;the combustion chamber. On fthelowersside of "the bottom wall are preferably roast :a :pairiofzparallel-ribs 1'4 (Fig. 3') "on opposite .sides :of lthe center, that rest on the surface of 'fthe ground :and provide .a substantial air space beneath :the combustion chamber to prevent overheating and possible warnin of the bottom wall. iNeara'the lower-end of the sidewall is art-upped :hole 1:5 o {receive ,a rfuelieed :pipe -:I 6; and 59D the :upper :side of the bottom wall is a radial irib 'L'l zcxtending from the .hole l5 to @the centercfithe bottom wall. As the "oilfiowsfrom t ne-pipe jlfi through :the hole 4-5 :and onto the .rib Ir! .a considerable amount :of the oil ;followsalong bothsiiies of themlbtowardthe inner end thereof before it -is iignited by :the :flames 'in the combustion chamber. This rib 1:7,, by conveying the entering oil :as above described, tends :to delay combustion and prevents cracking of the oil the instant :it enters the combustion chamber, and consequently avoids the formation of particles of carbonand asphalt-at the opening of the hole :15 into thecham'ber. Use e f-the device 'has shown that withoutthe rib ll, the oil cracks in the hole l5 and the portion-pf the :feed pipelbetween .hole .15 and :needle valve 28,, depositing particles of carbon and asphalt that .soon clog the flow duct. with the rib ll, such cracking and clogging of the .flow duct does :not occur. Extending vdateral-lyirom'thetop-edge10f the combu on chamber all :are three equally spaced arms 18, the outer ends of which terminate in upturnedfianges'tfi formed with tapped holes.

Driven into the ground at (points opposite the arms !:8,;ar.e-verti ca1:stakes 2&0 each f which is formed with vertically spaced holes .321 that are adap ed to register with tapped :holes of the flanges and receive machine screws '22 by which the combustion chamber 1:2 is securely attached to the stakes fill.

.Abo-ve lfillld axially aligned 'with the combustion chamber :5)? is :a smoke flue or stack 23, .into the lower end .of which is fitted the narrow upper end of .a conical hood 24 that overlies the open top of the combustion chamber 12' .andiis spaced several inches above the latter. The flue and its hood may be supported by any suitable means, but conveniently they are supported by screws 25 connecting the lower edge of the hood to the upper ends of the stakes 20.

26 designates an annular fuel tank or reservoir that encircles the smoke flue 23, and may be supported on the hood 24 by a plurality of spaced brackets 21. The inner wall of the tank 26 includes a vertical portion 26 that isspaced from the opposite portion 'of the smoke flue 23 and an inclined portion 26" that is spaced to the same extent from the opposite portion of the hood 24. This construction provides, between .pa'ssage for-atmospheric air that, of course, picks up considerable heat from the flue and transmits part .of it :to ;the:iuel in the tank, thus keeping the .fuel in freely flowing condition.

Connected into the bottom of the fuel tank 26, is the :upper end-of the :fuel-supply pipe l6; and in-this pipe is preferably incorporated a coil 16 that iliesl-aterally opposite the Y combustion chamher and absorbs enough radiant heat from the latter to :keep the oilflowing freely :and prevent the gumming and-clogging :of the pipe. Between the :coil L6 and the delivery end of the pipe l6 isamanuallyoperable needle valve 23, best shown in Fig. 10, for regulating the rate of flow.

ILocatedabove'the smoke fiue 23 directly across the rising current of hotgases, is a horizontal fan :29 that .-is .rotated by impingement of the gases thereon :anditself [acts to disperse these gasesmadially. EIheI-an -29 is'supported from the upper end of .the flue 23 :by .a. :standard, which may .consist of .a :rod 30 having on its upper end ailateral-ly bent armlsLand the arm .3l having adown-turned .end 32. Thehub of the fan 29 is itself rotatablymounted .on the lower end of ashort shalitsection '33 '(Fig. Al) and rests on a footlflof shaft '33. The lower vend .of rod 32 and the upper end .o'fshaft 33 are formed with interfitting .teeth'S'o and1315 respectively, by which shaft .33 is .suspendedfiom rod .32.; and the teeth 35 and 35 are maintained in engagementby .a sleeve 31 formed with a vertical slot 38 riding over 'a pin39 fixed in 'the'rod 32. When the 'fan 29 is to be applied or removedth'e sleeve is raised. By then lowering the sleeve, the'members '32 and 33 are confined against separation.

Hinged on the upper end of the flue 2-3, is a lid MI which, "when the heater is in use, is thrown back as shown in Fig. '1; but which may be closed when the heater is not in use to prevent the entrance of rain 'or snow.

The oil tank '25 "is provided on its top'with a filling nozzle 41 that is normally "closed by "a cap in the rim of which latter is formed a vent hole l3for 'the admission of air as the level of oil in the tank drops.

In the lower portion of the hood 2'4 is cut a notch M -normally closed by a hinged lid 45 '(Fig. 51)., through which a lighted match may be dropped to initially ignite the f-uel'in the combtu's'tion chamber.

It will be observed by'the :arrows in 'Fig. '1 that not only the products of combustion but also a considerable addition of entrained air flow upwardly through "the hood and smoke flue.

The heater above described, especially when employing a, relatively short smoke flue 2-3 and the tan 29, is more especially useful for the protection of "low growing vegetation, such as berry bushes, garden vegetables and the like.

Fig. 6 illustrates a modification of the form of the invention illustrated in Fig. l, in which there is introduced between the smoke flue 23 and the oil tank 26 an air draft flue 46 and a conical hood 4'! on the lower end thereof overlying and spaced from the hood 24. The flue 46 extends a considerable distance above the top of the smoke flue 23, and the parts 46 and 41, in association with the smoke flue 23 and its hood 24, create an annular passage for the updraft of secondary air that commingles with the products of combustion and primary air issuing from the top of flue 23 and substantially thins the smoke. In this construction a lid 4!), corresponding functionally to the lid 40 of Fig. 1, is hinged on the upper end of flue 46.

In this construction I have shown the annular oil tank 26 supported upon a ring-shaped bracket itself mounted on the hood 47, which bracket is also illustrated in Figs. '7, 8, 9 and 10, and will be more fully described in connection with said figures.

This construction is primarily useful for serving relatively high vegetation such as tall bushes and trees.

In. the form of the invention illustrated in Fig. '7, the flue 48 and hood 4'! of Fig. 6 are substituted by an extension flue 48 which may be of the same diameter as and coaxial with the smoke flue 23 and is mounted on the upper end of the latter as by vertical cleats 43. The lower end portion of the flue extension 48 is widened as shown at 50 and is open at its lower end so as to permit the ingress of secondary air above the flue 23 to mingle with the air and products of combustion issuing from the flue 23. The purpose of this construction is both to increase the effective height of the heater and to reduce the Smokiness. In this case, the lid 48". corresponding functionally to the lids M3 and 40 is hinged on the upper end of the flue extension 48. V

This last described structure is also well adapted to serve relatively high growing vegetation such as tall bushes and trees.

The structure illustrated in Fig. 10 follows that illustrated in Fig. 6, but shows a modification in the oil feed from the oil tank 26 to the combustion chamber l2. In this form of the invention, the cap 42 of the filling nozzle 4 l when screwed down tight, completely seals the space above the fuel against atmospheric air; and a pipe 5! depending from the bottom of the oil tank 26 and equipped with a manually operated cock 52, opens at its lower end into a pan 53 containing a shal low body of oil 54. The bottom of the pan 53 has a hole 55 that registers with a hole 56 in the outer end of a horizontal pipe 5! that leads into the combustion chamber; and in the pipe 51is the manually operable needle valve 28 which regulates the rate of feed. Atmospheric pressure on the body of oil 54 maintains a continuous uniform flow of oil to the combustion chamber, and as soon as the level of the oil 56 falls below the lower open end of the pipe 51, one or more air bubbles rise through pipe El and the body of oil in tank 25 to reduce the vacuum in tank 25 and thus permit the down-flow of enough oil from tank 26 to again close the lower end of pipe 5!. With this device, the in-flow of oil to the combustion chamber is continuous and uniform, while the flow of oil from tank 26 to pan 53 is intermittent. This oil feed system has the advantage over that shown in Figs. 1, 6 and '7, that the oil feed is more constant and uniform, since the movement of the oil to the burner from pan 53 is due only to a small body of oil of, substantially constant volume seeking its level, and not.

to a much larger body of oil in tank 26, the weight of which is constantly lessening as the oil is consumed. Figs. 8 and 9 illustrate the structural features of the ring-shaped bracket shown in Figs. 6, 7 and 10 for supporting the annular oil tank 26. This bracket, which is preferably a casting, comprises a flat ring 53, on the inner periphery of which are spaced depending lugs 59, the inner faces of which are inclined, as shown at 60, to fit the upper surface of a conical hood. In Figs. 6 and 10 the lugs 59 are shown as resting on the upper surface of the hood 41, and in Fig. '7 they are shown as resting on the outer surface of'the' hood 24. The internal diameter of the ring58 is sufficiently greater than that of the flue member which it encircles to allow the free up-flow of air between the lugs 59.

Practical tests of the heater above described and shown in the drawings have satisfactorily proved that it can be operated by very low grades of oil-even crude oil-and yet without enough smokiness to be injurious to the fruit. The location of the oil tank in relation to the flue has the advantage of keeping the oil sufliciently warm to insure its flowing freely to the combustion chamber. The devices illustrated and described in Figs. 6, 7, and 10 for introducing secondary air to the products of combustion rising from-the main smoke flue are very eflicient in the directionv of reducing smokiness, and they possess the additional advantage of converting the heater from a low vegetation heater to a high vegetation heater. The mounting of the associated parts is such that the fines, hoods and combustion chamber can be readily dismantled and reassembled when required for cleaning; the ring-shaped brackets shown in Figs. 6, '7, 8, 9 and 10 not being required to be attached to the parts with which they cooperate.

Variations and modifications in the details of structure and'organization may be resorted to within the scope and coverage of the claims.

I claim:

1. In a heater of the class described, the combination of a pan-shaped combustion chamber having the bottom thereof substantially flat and having the interior thereof above said bottom free of internal obstructions, said bottom having a rib extending radially inward from the sidewall of said chamber to a point near the center of said bottom, said side-wall having an oil-feed aperture therein located directly above said rib at its juncture with said chamber side-wall and adapted to release oil to the outer end of said rib for conduction therealong toward the center of said combustion chamber.

2. In a heater of the class described, the combination of an open-top pan-shaped combustion chamber adapted to have fuel oil fed thereto from an exterior source as required for the maintenance of combustion, a smoke flue mounted in spaced coaxial relationship above said open-top combustion chamber, and a hood depending from said flue and communicating axially therewith, said hood having its open lower end of a diameter not less than the diameter of the open-top of said combustion chamber and spaced therefrom to provide an annular space between said open-top combustion chamber and said hood in direct communication with the outer atmosphere.

3. In a heater of the class described, the combination of an open-top pan-shaped combustion chamber adapted to have fuel oil fed thereto from an exterior source as required for the maintenance of combustion, a smoke flue mounted in spaced coaxial relationship above said open-top combustion chamber, a hood depending from said flue and communicating axially therewith, said hood having its open lower end of a diameter not less than the diameter of the open-top of said combustion chamber and spaced therefrom to provide an annular space between said open-top combustion chamber and said hood in direct communication with the outer atmosphere, and a tube open at both ends and surrounding said smoke flue and spaced therefrom to provide a vertical air draft passage on the outside of said flue.

4. In a heater of the class described, the combination of a pan-shaped combustion chamber having the bottom thereof substantially flat and having the interior thereof above said bottom free of internal obstructions, said bottom having a rib extending radially inward from the sidewall of said chamber to a point near the center of said bottom, said chamber side-Wall having an oil-feed aperture therein located directly above said rib at its juncture with said chamber side-wall and adapted to release oil to the outer end of said rib for conduction therealong toward the center of said combustion chamber, a smoke flue mounted in spaced co-axial relationship above said open-top combustion .chamber, and a hood depending from said flue and communicating axially therewith, said hood having its open lower end of a diameter not less than the diameter .of the open-top of said combustion chamber andspaced therefrom to provide an annular space between said open-top combustion chamber and said hood in direct communication with the outer atmosphere.

5. In a heater of the class described, the combination of a pan-shaped combustion chamber having the bottom thereof substantially flat .and having the interior thereof above said bottom free of internal obstructions, said bottom having a rib extending radially inward from the sidewall of said chamber to a point near the center of said bottom, said chamber side-wall having an oil-feed aperture therein located directly above said rib at its juncture with said chamber side- Wall and adapted to release oil to the outer end of said rib for conduction therealong toward the center of said combustion chamber, a smoke flue mounted in spaced co-axial relationship above said open-top combustion chamber, a hood depending from said flue and communicating axially therewith, said hood having its open lower end of a diameter not less than the diameter of the open-top of said combustion chamber and spaced therefrom to provide an annular space between said open-top combustion chamber and said hood in direct communication with the outer atmosphere, and a tube open at both ends and surrounding said smoke flue and spaced therefrom to provide a vertical air draft passage on the outside of said flue.

6. In a heater of the class described, the combination of an open-top combustion chamber adapted to have fuel oil fed thereto from an exterior source as required for the maintenance of combustion, a smokeflue mounted in spaced coaxial relationship above said open-top combustion chamber, a hood depending from said flue and communicating axially therewith, said hood having its open lower end of a diameter not less than the diameter of the open-top of'said combustion chamber and spaced therefrom to provide an annular space between said open-top combustion chamber and said hood in direct communication with the outer atmosphere, and an air draft flue encircling said smoke flue with clearance and extending above the top of said smoke flue for introducing pre-heated secondary air to the products of combustion and reducing the smoke.

7. In a heater of the class described, the combination of an open-top combustion chamber adapted to have fuel oil fed thereto from an exterior source as required for the maintenance of combustion, a smoke flue mounted in spaced co-axial relationship above said open-top combustion chamber, a conical downwardly-flaring hood depending from said flue and communicating axially therewith, said hood having its open lower end of a diameter not less than the diameter of the open-top of said combustion chamber and spaced therefrom to provide an annular space between said open-top combustion chamber and said hood in direct communication with the outer atmosphere, and an air-draft flue having a conical hood at its lower end, said air-draft flue and hood encircling said smoke flue and its conical hood respectively with clearance, said airdraft flue extending above the top of the smoke flue for introducing pre-heated secondary air to the products of combustion and reducing the smoke.

GEORGE ANDERSON.

Images