US2673726A - Jet tobacco curer - Google Patents

Description

March 30, 1954 H, A. OLDENKAMP JET TOBACCO CURER 2 Sheets-Sheet l INVENTOR HENRY A. OLDENKAMP xmvaazz/ ATTORNEY led Aug. 16, 1950 Patented Mar. 30, 1954 UNITED STATES PATENT OFFICE JET TOBACCO CURER Henry A. Oldenkamp, Valhalla, N. Y., assignor to American Machine and Foundry Company, a. corporation of New Jersey Application August 16, 1950, Serial No. 179,710

8 Claims. 1

This invention relates to direct fired tobacco curing apparatus and more particularly to a jet type burner for use in curing tobacco.

Before tobacco is placed on the market it is the usual practice after harvesting, to store it in a tobacco curing barn to cure the tobacco leaves. To assist in this curing process the temperature in the tobacco curing barn is artificially raised by means of a suitable coal, wood or oil burning furnace. Since it is not desirable that the tobacco leaves being cured be contaminated by either soot or oil smudge, a central heating system is frequently employed which allows heat to be radiated while carrying ofi the flue gases. This practice decreases the possibility of contaminating the cured tobacco by either soot or oil smudge. On the other hand, this requires a high investment inequipment and a great deal of heat is lost up the flue pipe. This investment in equipment andwaste of heat increases the cost of curing the tobacco.

It is an object of the present invention to-provide a direct fired oil burner which will be of simple and inexpensive construction and of high burning eiiiciency.

It is a further object of this invention toprovide an oil fired burner wherein fuel will be so completely oxidized thatthe combustion products can be discharged directly into the tobacco curing barn and there will be no danger of contaminating the tobacco leaves being cured.

It is an object of this invention to provide an oil burner unit which will be of such construction that the accumulation of carbon in the burnor will be avoidedwithout interfering with the complete combustion of theiuelburned therein.

Another object is to move the hot combustion products away from the combustion chamber as rapidly as possible.

A further object is to utilize thesame source of air for supplying air for combustion as well as for rapidly moving the hot combustion gases away from the fire box.

Other objects and featuresof the invention will appear as the description of the particular physical embodiment selected to illustrate the invention progresses. In the accompanying drawings, which form a part of this specification, like characters of reference have been applied to corresponding parts throughout the several views which make up the drawings.

In the accompanying drawing:

Fig. 1 is a sectional side elevationoi the combustion chamber assembly, and

Fig. 2 is a plan view of the entirejet burner, and

Fig. 3 is a sectional end elevation of the combustion chamber assembly, taken on line 3-3 of Fig. 1, and

Fig. 4 is a partial end elevation of the burner nozzle clamp, and

Fig. 5 is a schematic plan view of a typical hook up of the burner to a tobacco curing barn.

With reference to the drawings, the jet burner consists of a combustion chamber assembly C, a suitable fan F, a pump P and a motor M which drives the fan F as well as the pump P. There is also provided a transformer T which fur nishes the necessary'high voltage for the ignition i. e. the spark plug of the burner. The fan, motor, pump and transformer are conveniently mounted on a base plate 3 (Fig. 2). Pump P is connected by means of a tube S to a source of supply of oil (not shown). A return tube R. is provided to return fuel pumped in excess of that required back to the fuel tank.

The combustion chamber assembly as illustrated in Figs. 1 and 3 consists of a combustion chamber jacket ID, a combustion chamber cap l2, a combustion chamber wall l4 and a spinner plate It. The combustion chamber jacket in is connected to the fan outlet by means of a transition duct I8 (Fig. 2).

The wall of the combustion chamber i4 is cylindrical in design and is mounted at the mouth end of the jacket Ill. The mouth end of jacket [0 has a short portion I I which is parallel to the mouth end of the combustion chamber Hi. The combustion chamber I4 is spaced from the chamber jacket [0 by means of three equally spaced suitable brackets 29 (Figs.- 1 and 3). The end of the combustion chamber I4 is flush with the mouth end of the jacket It and has a continuous annular spacing "22 between the outer periphery of said wall 14 and the inner surface of jacket Ii]. A spacing of 5 2 of .an inch has been found very satisfactory for this purpose. It has been found for best results that this spacing must not be less than & of an inch nor more than 1% of an inch.

The combustion wall or cylinder M is provided with two rows of equally spaced holes 24 at its open end. The size and location of these holes playan important part in obtaining a good mixture and in preventing undesirable carbon formation and deposits. Applicant has found that theseholes should preferably be between A and $6 inch indiameter and should be spaced from each other between inch and inch. Therfirst row of holes should be between /2 inch and one inch from the end of the combustion chamber I4.

Within and near the opposite or bottom end of combustion cylinder [4 is located the cup shaped combustion chamber cap 12 which is secured to suitable lugs 26 of brackets 26. The cup shaped chamber i2 is mounted so as to provide a narrow uniform annular opening 28 between the outer wall of cap l2 and the inner wall of cylinder i 4. This opening should be between &4 of an inch and of an inch. A spacing of "3 2 of an inch has been found very satisfactory for this purpose.

The bottom portion of said cup shaped chamber cap I2 is also provided with a centrally located circular opening 30 through which a suitable nozzle 32 protrudes. Nozzle 32 is held and adjustably supported by 3 suitable nozzle clamp lugs 34 (Figs. 1, 3 and 4) each of which is secured to one of the brackets 20 mentioned above. By loosening or removing clamp nut 36 the burner nozzle 32 may be adjusted horizontally or easily removed for inspection or cleaning. The nozzle 32 by means of a tube 38 is connected to the pump P.

Within the bottom of the cup shaped cap I2 is also mounted the spinner plate l6 which by means of a plurality of short narrow lugs 40 is attached to the bottom of the cup shaped cap 12 in such a manner that said plate is spaced a short distance of approximately of an inch from the bottom of said cap I2. The spinner plate I6 is also provided with a centrally located round opening 42 which is surrounded by a row of small holes 44. Besides each hole there is provided a plurality of radially cut louvers 46 employed for the purpose of giving the passing air stream a turbulent or swirling motion and to also keep the plate from accumulating carbon.

The bottom portion of cap [2 is also provided with an opening 48 through which a spark plug 56 projects into said cap. The spark plug 53 is held by a suitably shaped and bored block 52 which is secured to the bottom portion of cap i2.

In order to prevent oil from being sprayed by the burner if it fails to ignite or the flame goes out, there is provided a conventional Visa flame detector 58. This detector will cause the fuel pump to stop operating if the flame in the combustion chamber should go out. The Visa flame detector 58 is mounted inside of the tube 56 and is connected to the cup-shaped cap l2 over an opening 54 formed therein. These components may be readily serviced by removing the cover plate 60 shown in Fig. 2.

There is also provided a fusible link 64 mounted in such a manner that if the temperature in the tobacco curing barn goes above a predetermined amount it will cause the fusible link 64 to melt which in turn will result in a switch being actuated so as to cause the oil burner apparatus to be shut 01f automatically.

For purposes of illustration the fusible link 64 is shown connected to a hook 62 attached to one side of the tobacco curing barn. One end of the wire 66 is connected to the other end of the fusible link 64 and the other end of the wire 66 is connected to a switch held normally closed when the wire 66 is taut. A spring 10 is provided for opening the switch 68 automatically as soon as the tautness of the wire 66 ceases due to the fusing of link 64. As soon as the link 64 fuses, thus releasing the wire 66, the switch 68 will be opened thereby causing the fuel burner to be shut off.

A solenoid operated valve 39 is mounted in the oil pipe line 38. The operation of the solenoid 4 operated valve 39 is controlled by a thermostat 4| having a control setting knob 43.

Different stages are frequently followed in ouring tobacco which require low temperatures and no circulation of air and other times moderate temperatures with circulation of air and still other stages no circulation of air and very high temperatures. These objectives are readily obtainable with the present apparatus by throwing the selector switch 13 and the temperature knob 43 to obtain the results desired.

As has been previously described this fuel burner is especially well adapted for use in connection with tobacco curing barns. There is shown in Fig. 5 a schematic illustration of the manner in which my jet burner may be connected with a heat distribution system in a tobacco curing bar. In the arrangement chosen to illustrate my jet burner there is provided a fire box l5 which is connected to a heat distributing header 16. The header [6 in turn has hollow distributing arms 18 extending therefrom which are made up of spaced sections which allow the heat to escape between the joins 86. As will be noted my jet type burner designated generally by the letter C is mounted outside of the tobacco curing barn 82 and the heat distribution system is mounted on the inside of the tobacco curing barn. The heat distributing system shown in Fig. 5 is fully disclosed and claimed in co-applica-tion S. N. 186,972 filed by John A. Maul and Philip Kaftol on September 27, 1950.

The operation of my invention may be briefly described as follows:

When the green tobacco leaves have been hung in a tobacco curing barn the burner apparatus is turned on by setting the thermostat control knob 43 at the temperature desired. The selector switch 13 is usually connected with contacts 12 in the initial curing stage (sometimes referred to as the yellowing stage or yellow leaf stage). When the burner is turned on it causes the motor M to operate and the normally closed solenoid valve 39 to be opened. The rotation of the motor M causes the fan F to rotate and the fuel pump P to operate to thereby force oil to the nozzle 32 which sprays the oil at the rate of approximately 2 gallons an hour through the opening 42 into the burning chamber I l. The fuel pump P capacity may range from 1.75 to 3 gallons of fuel per hour.

Any oil that is pumped in excess of that required by the burner flows through a by-pass back to the source of fuel through the return duct R. When the normally closed solenoid valve 39 is opened the spark plug 50 is also in operation to ignite the sprayed fuel. Similarly the Visa flame detector also goes into operation so as to shut off the entire unit in the event the fuel does not ignite in the time allowed and ii the burning does not continue during the period oil is being pumped and sprayed into the combustion chamber M.

The fan F supplies air at the rate of approximately to cubic feet per minute to the burning chamber I4 through the annular orifice 28 as well as through the louvers 46, holes 56 in the spinner plate l6 as well as through the opening 36 underneath and out through the sides of the spinner plate l6. Some air is also delivered into the combustion chamber Hi through the openings 24 so as to obtain additional burning in the chamber. An additional quantity of air is forced through the annular orifice 22 around the outside perimeter of the combustion taking place primarily for providing an excess of air to be mixed with the hot combustion gases coming out the combustion chamber.

All of the air forced through the different openings mentioned causes the heat to be immediately and rapidly carried away from the area in which the actual combustion takes place. In this respect it will be noted that in ordinary burners it is desirable to maintain the heat concentrated in one area as long as possible so as to obtain a maximum heat transfer. In the present case however it is desirable to remove the heat as quickly as possible so as to cause it to be immediately conducted into the heat distributing apparatus.

As has previously been described if the fusible link should melt during the period Of operation the normally closed switch 68 will be automatically opened by means of spring 'Hl so as to shut off the oil burning apparatus.

When the desired temperature in the barn is attained the thermostat shuts off the oil burner. Since the selector switch 13 has been connected to the contacts :12 the motor M stops operating whenever the thermostat 4| shuts off the motor.

In the second curing stage it is often desirable to employ a moderate heat and to have a higher amount of circulation of air in the tobacco curing barn. This stage is sometimes known as the dry leaf stage. In this case the thermostat ti is turned to a higher temperature and the selector 1 switch it is connected to contacts l4. This causes the oil burner to operate in the manner heretofore described so as to raise the temperature and maintain the temperature in the tobacco curing barn at a higher temperature. In this case however, in the intervals between the cycling of the oil burner the motor M continues running thereby rotating the fan F because selector switch l3 is connected to the contacts 14. The rotation of the fan F circulates air through the heat distributing system even though there is no flame burning in the combustion chamber C. The normally closed solenoid valve "ll however is maintained closed even though the motor M operates. Therefore even though fuel pump P is operated all of the oil passes through the by-pass back through the return duct R to the fuel source and none of it passes to the spraying nozzle 32.

In the third curing stage sometimes known as k lling the stem stage, it is desirable to have a high degree of heat with a minimum of circulation. In this case the thermostat control knob E3 is turned to the temperature desired and the selector switch 13 is connected to contacts 12. The oil burner will then operate cyclically to raise the temperature of the tobacco curing barn to that desired and when the thermostat shuts off the oil burner the fan F will not continue to rotate during the off cycle because the selector switch it has been connected to the contacts 12.

It will thus be seen that I have provided an oil burning apparatus for use in tobacco curing barns which is highly versatile in that the farmers can obtain the type and amount of heat they desire by simply settng a few control knobs.

Applicant has found that the specific dimensions given in the foregoing description are desirable to obtain complete oxidation and it is believed that fairly close adherence to these dimensions are needed to provide correct functioning of the burner.

The invention above described may be varied in constructions within the scope of the claims, for the particular. device selected to' illustrate the invention is but one of many possible embodiments of the same. The invention, therefore, is not to be restricted to the precise details of the structure shown and described.

What is claimed is:

1. A fuel oil burner having a fuel burning capacity between 1.75 and 3 gallons per hour, comprising a cup-shaped member having a hole in the center portion thereof, an atomizing nozzle positioned at said opening for spraying fuel therethrough, a spinner plate spaced from the opening formed in said cup a distance of approximately one quarter inch and having a hole formed in the center part thereof, louvers formed in said spinner plate for swirling the air drawn through the center opening formed in said cup around the sprayed oil, additional holes positioned between said louvers and said central opening, a straight walled tubular shell surrounding the open end of said cup and having a uniform annular spacing from the lip thereof of not less than ,4 of an inch and not more than of an inch, a second tubular housing surrounding said first-named tubular shell havin an annular separation from the far end of said tubular shell which is not less than of an inch and not more than Te of an inch spaced therefrom and a device for igniting said sprayed fuel.

2. A jet type oil burner having a fuel burning capacity between 1.75 and 3 gallons per hour comprising, a tubular shell of uniform diameter throughout its length, a second tubular shell surrounding and having an annular spacing between one end of the first-named tubular shell and one end of the second tubular shell which is not less than ,4 of an inch and not more than T'sof an inch, said second tubular shell tapering outwardly away from said end of said first-named shell, a cup-shaped member having the lip portion thereof projecting inside of one end of said first-named tubular shell a short distance, said cup-shaped member having a hole formed in the center thereof, means for spacing the portion of said cup-shaped member projecting inside of said firstnamed tubular shell a distance from said firstnamed tubular shell of not less than of an inch nor more than g of an inch, a plate having a plurality of radially extending louvers formed in the face thereof mounted at a spaced distance from the hole formed in the center of said cupshaped member for swirling air around the inside of said inner shell, a nozzle for sprayin fuel inside of said first named tubular shell and a fuel igniter for igniting the fuel so sprayed inside of said first named tubular shell.

3. A jet type burner of a fuel burner capacity between 1.75 and 3 gallons per hour and having a combustion chamber comprising a tubular sleeve having a uniform diameter throughout its length which is open at both ends, said sleeve having two rows of holes formed in one end of said sleeve which are spaced a distance of approximately five-eighths of an inch from each other, an outer sleeve surrounding the end of said inner sleeve having the holes formed therein, said outer sleeve being spaced from said inner sleeve a distance of not less than ,4 of an inch and not more than 1 g of an inch and flaring outwardly from the opposite end of said inner sleeve, a fuel spraying nozzle, a cup-shaped cap extending a short distance inside of the opposite end of said inner sleeve and having a diameter which allows an annular spacing between the portion of said cupshaped member and extending inside of said inner sleeve and the inner sleeve of not less than 4, of an inch nor more than 1*; of an inch, said cup shaped member having an opening formed in the center portion thereof through which the discharge end of the fuel spraying nozzle extends, a pump for forcing fuel through said nozzle sprayer to spray fuel inside of the combustion chamber comprising the inner sleeve and the cup-shaped member, a fan for delivering a predetermined quantity of air through said spacings and openings into the combustion chamber, and a connecting duct interconnecting said fan with said outer sleeve to conduct said air to said spacing and openings, and a spark plug for igniting said sprayed fuel.

4. A burner having a fuel burning capacity between 1.75 and 3 gallons per hour comprising a cup-shaped cap having an opening in the center part thereof through which fuel and air can pass, a straight walled shell extending from said cupshaped member and surrounding the lip end of said cup-shaped member at one end, said straight walled shell being of such diameter that there exists a continuous annular spacing between the lip end of said cup-shaped member and one end of said shell through which a continuous band of air can pass, the far end of said shell having a plurality of circumferential rows of holes formed therein which are spaced approximately of an inch from each other, an outer shell tapering towards the far end of said first-named shell, the

end of said outer shell being mounted flush with said inner shell and being spaced from said inner shell a distance which allows an annular spacing to be formed therebetween of not less than A of an inch nor more than g of an inch, a fan for forcing a predetermined quantity of air through said outer shell past the annular spacings formed between said outer shell and inner shell and the inner shell and the lips of said cups and through the opening formed in the center part of said cup-shaped member, a fuel nozzle mounted in the center opening of said cup-shaped cap for injecting fuel into said cup and inner shell for burning, and a fuel igniter for igniting the fuel so injected.

5. In a jet type burner having a fuel burning capacity between 1.75 and 3 gallons per hour, a cup-shaped member having a center opening formed in one end thereof, a spinner plate having an opening formed in the center portion thereof and having louvers formed in said plate for causing air passing there past to have a swirling motion, means for spacing said spinner plate from the bottom portion of said cup-shaped member to allow air to pass therethrough and therearound, a straight walled tubular member having one end extending around the outside of the lip portion of said cup-shaped member and having an inside diameter of said end larger than the outside diameter of the lip portion of said cup-shaped member so as to allow a continuous annular spacing therebetween of not less than ,4 of an inch nor more than rs of an inch, means for rig idly spacing said inner shell from the lip end of sair cup-shaped member, an outer shell having one end tapering towards the opposite end of said inner shell so that the ends of both the inner shell and the outer shell are flush, the narrow tapered edge of said outer shell having a short portion extending parallel to the end of said inner shell and having an inside diameter which permits an annular spacing to be formed between the outer shell and the inner shell of not less than of an inch nor more than 6 of an inch, a fuel injecting nozzle for spraying fuel through the opening formed in said spinner plate and said cupshaped member into the inside of said combustion chamber consisting of the inner shell and the cup-shaped member, a source of air under pressure for forcing a predetermined quantity of air through the spaces formed between said inner shell and said outer shell and the inner shell and the lip of said cup-shaped member as well as through the center opening of said cup-shaped member and spinner plate, and a fuel igniter for igniting fuel sprayed into said combustion cham her.

6. A combustion chamber for a jet type burner having a fuel burning capacity between 1.75 and 3 gallons per hour comprising, a straight walled shell having two coaxial rows of holes formed at one end thereof which are spaced approximately one half inch from each other and the row nearest the end of the straight walled shell is approximately three quarters of an inch from the end of said straight walled shell, a cup-shaped member having a lip portion extending a short distance inside of the opposite end of said straight walled shell, said lip portion of cup-shaped member having an outside diameter which is spaced not less than /64 of an inch nor more than A of an inch from the inside diameter of said opposite end of said inner shell, an outer shell surrounding said inner shell and having one end mounted flush with the end of said inner shell having said holes, said outer shell, after extending parallel with said inner shell, for a short distance from the end thereof said outer shell flares outwardly from the inner shell, a fuel spraying nozzle extending through the opening formed in the center portion of said cup-shaped member for spraying fuel through said opening into said combustion champer, a source of air under pressure connected to said outer shell for causing air to flow between and through the opening formed in and by said outer and inner shells and said cup-shaped memher, and a fuel igniter for igniting fuel so sprayed into said combustion chamber.

7. A jet type oil burner having a fuel burning capacity between 1.75 and 3 gallons per hour comprising, a tubular shell for uniform diameter throughout its length, a second tubular shell surrounding and having an annular spacing between one end of the first named tubular shell and one end of the second tubular shell which is not less than & of an inch and not more than 1% of an inch, said second tubular shell tapering outwardly away from said end of said first named tubular shell, 9, cup shaped member having the lip portion thereof projecting inside of one end of said first named tubular shell a short distance, means for spacing the portion of said cup shaped member projecting inside of said first named tubular shell a distance from said first named tubular shell of not less than & of an inch nor more than of an inch, a, plate having a plurality of radially extending louvers formed in the face thereof mounted on the inside of said cup shaped member at a spaced distance from the hole formed in the center of said cup-shaped member, a fuel spraying nozzle positioned at the opening formed in said cup-shaped member for spraying fuel inside of said first named tubular shell, a fan for blowing air through said various openings to mix said sprayed fuel with air, and an igniting device for igniting the fuel so sprayed through said nozzle.

8. A jet type burner having a fuel burning capacity between 1.75 and 3 gallons per hour for used in connection with a tobacco curing barn having a duct type heat distributing system mounted therein, comprising a straight walled inner shell having two circumferentially spaced rows of A inch holes, formed at one end of said shell at a distance of an inch from the end thereof and wherein the holes are separated from one another a distance of approximately inch, an outer shell surrounding and spaced from said inner shell a distance approximately of an inch, a source of air for forcing air between said inner shell and said outer shell out through the spacing therebetween and through the holes formed in said inner shell to cool said inner shell and to force the hot combustion gases through the distribution system, a cup-shaped member having the open end thereof extending into the opposite end of said inner shell, said cup-shaped member having an outside diameter which will allow a 3 1 inch spacing between and all around the cup-shaped member and the inner shell, a nozzle projecting through an opening formed in the center part of said cup-shaped member for spraying fuel therethrough, a spinner plate spaced from the opening formed in said cupshaped member for imparting a, swirling motion 19 to the air stream forced through said center opening, a supply of air for forcing air through the spacing formed between said cup shaped member and inner shell to effect a cleaning action thereon and a spark plug for igniting the fuel so sprayed.

HENRY A. OLDENKAMP.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,268,464 seippel Dec. 30, 1941 2,417,445 Pinkel Mar. 18, 1947 2,419,626 Bugler Apr. 29, 1947 2,446,059 Peterson et a1 July 27, 1948 2,477,584 De Zubay Aug. 2, 1949 2,510,645 McMahan June 6, 1950 2,513,325 Hundstad July 4, 1950 2,522,081 Allen Sept. 12, 1950 2,541,170 Mayers et al Feb. 13, 1951 2,552,492 Nathan May 8, 1951 2,549,858 Sforzini Apr. 24, 1951 2,565,843 Dennison Aug. 28, 1951 2,611,599 MacCracken Sept. 23, 1952

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