US1490658A - Oil burner - Google Patents

Description

April 15, 1924. 1,490,658

.L. H. BRADY OIL BURNER Filed Oct. 5 1.922 2 Sheets-Sheet 1 21 L. H. BRADY A ril 15, 1924.

OIL BURNER Filed OCB- 5. 1922 2 Sheets-Sheet 2 a mi'fiifij Patented Apr. 15, 1924.

LEON H. RWY 01 LAKEWOOD, O0.

OIL BURNER.

Application and Gctober s, 1922. Serial no. team.

which the following is a Specification.

itedby the point at which the The present invention relates to oil burners and has for its object to provide an oil burner so'constructed as to embody the features enumerated below.

S ray nozzles in use in oil burners aresub ect to stoppage due "to solid particles carried by the oiland deposited in the small passages or outlets. Stoppa e also results from carbonization of fuel oil, particularly of hieavy grade, when preheated air supply is use When stoppage takes place the burner is usually shut down while it is bein cleaned, causing loss of time and possible amage to the work in the furnace. Centrifugal spray nozzles require the burner to be taken apart in order to get at the various small passages to clean them, which is diflicult on account of the heat.

Centrifugalspray nozzles, are the most eflicient in atomlzing fuel oil and securing rapid and economical combustion. The .action of these nozzles depends upon the ressure, viscosity and specific gravity or the oil and the size, number, disposition, relation of the inlet to the outlet openings and the form of the discharge chamber, these features of construction eing fixed at the time the nozzle is made and not-being susceptible thereafter to adjustment required by other physical conditions of the 011 for which the nozzle was designed or for other grades of fuel oil. I

A further practical consideration is'the use of a preheated air supply to the burner which results in vaporization of the. oil

spray after leaving the burner-and a condition of combustion that approaches that of gas. A great saving of oil due to the high temperature of the oil vapor when it enters the zone of combustion is the result.

The temperature of theair su ply is lim- 181 oil will gasifg or carbonize in the spindle ornozzle, whic are usually exposed tothe hot air or are protected from it by an intervening casing through which cool airis forced or induced.

, To secure the advantages of the centr fugal spray, to afford means of adjustment of the nozzle to various grades of oil andopcrating conditions or to vary the quantity and she. e of the spra while using the same grade 0 oil, to provi e devices for removing solid materials from the oil passages and disposing of them without shutting down the burners, to enable the burners to continue in operation as common, straightspray burners if the grooves become clogged and to provide means for using preheated air and mixing it with the oil spray, this burner has been invented.

In the accompanying drawings- Fig. 1 is a longitudinal section of the burner. p

Fig. 2 is a fragmentary longitudinal section through the nozzle. I

Fig. 3 is a side elevation of the valve head.

Fig. 4. is a cross section on the line H of Fig. 2.

Fig. 5 is a cross section on the same line showing'the valve head turned from the position shown in Fig. 4.

Fig. 6 is a fragmentary cross section of the air cap and air damper.

The burner body 10 has its outercasing 11 involuted to form an inner tube 12 spaced from the oil tube 13 which is threaded at 50 on an enlarged section 14 into a bracket 15 which rests u on the shell of the burner threaded at 18-to receive a valve gland 19.-

which is threaded at 47 to receive valve stem 20. Valve gland 19 .is of hexagonal form at its largest diameter to facilitate its removal by a wrench together with the oil tube. The valve wheel 42 serves to turn stem 20 for adjustment or for regulating or stopping the flow of oil through the supply space 21 or the discharge chamber 34 o the nozzle 22 which is threaded into enlargement 23 of tube 13.

The forward end of the air tube 12 is contracted to form a conical air nozzle 2A: spaced from the oil nozzle 22 by the space 25 and having an opening 26 larger than the out let 35st the oil nozzle,

The shell of the burner body is threaded 'at 28 to receive a threaded air cap 29 with conical termination 34: with a circular central openin 35 for the oil. Chamber 33 is provided with two or more grooves or slots 36 arranged in groups the grooves of each group being alike, as to length cross sec tion and other characteristics and equally spaced around the circumference of the discharge chamber 33. lhese grooves are preferably straight and parallel to the axis of the chamber '33 and communicate at their rear ends with the oil space 21 but. do not extend the full length of chamber 33. The various groups may differ from each other.

The inlet 40 of the oil nozzle 22 is conical and forms a valve seat for the needle valve 41 formed on the larger part of the oil valve stem 20 back of the valve head 32., thus providing for stopping or regulating the oil flow from oil space 21 to discharge chamber 33 and preventing damage of the inner surfaces of 33 and 3% by jamming the valve head against them.

Valve head 32 is provided with a group of two or more groovcs37 parallel to its axis for part of their length then turning at an angle and continuing in a helical form to the forward end of the valve head thereby forming continuous passages through which oil may pass under pressure from oil chamber 21 to discharge chamber 34 reaching the latter at an. angle to its axis and thereby acquiring a whirling motion in the chamber 34 which results in a conical jet whirling spray through the outlet 35. v

Valve head 32 also bears additional groups of grooves 38 which are like grooves 37 in form but do not extend to the rear end of the valve head.

Grooves 3'2 and 38 are alil-re in their r spective groups and are equally spaced. around the circurnl erence'oi the valve head but the various groups may dilier from each other in length cross section or other characteristics.

in the position shown in Fig. i. the grooves 36 and 38 meet and form continuous passages with results like grooves 3'? and thereby amount of oil delivered to ch"- Turning the valve wheel serves the grooves into various combination the flow through grooves 3"? only t tial or complete connection between 33 and 33, in addition to grooves 7.

For each revolution of the valve menses 42, the head 32 will be withdrawn or advanced in the chamber 33 and various quancities of oil will be delivered into chamber 33 for the various relative positions of the grooves on the valve head with those in the chamber. These grooves also serve to catch and crush small solid particles asthe valve head is turned, thereby tending to avoid stoppage.

The form of the conical jet depends upon the rate of whirling motion attained in chamber 3 The farther the valve head is withdrawn from chamber 33, the, longer becomes the column or jets of oil, which slows down the motion and causes a narrower jet. The reverse is also true.

The conical jet, then can be varied both in quantity and form by turning the valve handle 42, thereby varying the length of the chamber 33 and at the same time repeating the groove combinations for each revolution.

It is also plain that if all the grooves become clogged, the valve head can be completely withdrawn from the chamber 33, thereby affording direct communication between passage 21' and. orifice 35 in which condition the burner will continue to operate and will tend to clean itself by-the wash of the oil over the surfaces.

The construction of the body of the burner is such that the tube 13 is outside the shell and away from the air supply passing throu h the air space 39, thereby permitting tlie use of highly preheated air without gasifying or carbonizing the fuel oil in the oil spindle or nozzle, since the forms of the air nozzle 24 and air cap 29 cause cool air to be drawn along the oil spindle and around the oil nozzle through the space 25, thereby preventing overheatlhe air cap 29 is adjustable axially whereby the volume of air issuing from the burn or and the position the zone of combustion may be governed.

The air cap 29 is finished at 42 to receive an air damper 43 with. an outlet which may be of ditlerent or equal area to air inlet 31. Air cap 29 is locked in position by locknut it. and is provided with segmental openings l8 which register with similar openings 49 in air damper l3 so that with openings 43 and &2 out of register and with air cap 29 screwed. down upon air nozzle no air can pass through the burner. as burner may be started with cool air as the furnace warms up cap 29 may he brought still further oh its seat 24;. Further in fease in the :JUG of the air due to its :reased temperature calls for a larger out is than care by brin iv-4g on and d3 adual er uh 7 a: I sired the cor on I S F a. the l or. e

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Air damper cap 43 fits closely against the contact surfaces of air cap 29to prevent es-- cape of air and is held to its seat by screws 53 but allowed to rotate to the required extent by slots "51 which engage screws 53.

It will be seen that by the construction shown I have provided an improved oil burner of simple and cheap construction which can be easily adjusted and operated to maintain its efficiency and economy. The shell of the burner, involuted as shown at 12, forms a short interior tube of comparatively large diameter and open at its rear end to the atmosphere. This construction provides for mounting the oil supply tube at the back and outside of the shell, and extending into the air tube, thus leaving the oil tube and nozzle visible and accessible from the back, and spaced from the heated air supplied through the inlet 31. This latter condition is of practical importance and advantage when the air is pre-heated to temperatures high enough to carbonize or gasify fuel oil in an oil tube or nozzle directly surrounded by hot air.

The use of a hot air supply to an oil burner results in great saving in oil consumed and in higher temperatures in the furnace than are possible when cold air is used. My burner will operate with steam or compressed air, but is particularly adapted to use air of less pressure than 16 oz. to the square inch, since the production of the latter is cheaper and its use is more eflicient than that of the former two. A great objection to'the use of steam or compressed air is that they have such high velocities that oil is carried through and out of the furnace before combustion is complete. Compressed air, when discharged at low or atmospheric pressure, suffers a great drop in temperature so that a cooling effect results at the point where combustion should begin, thereby delaying the combustion. High velocity and cold air supply result in lower temperatures and the consumption of more oil than 18 required when using low pressure, low velocityand warm or hot air.

It will be understood that the oil fed through the tube 13 and nozzle discharges into the air stream entering through the tube 12 and the space 39, and mixes with the air (or steam if used) to form a combustible mixture, but it does not depend upon the air or steam to induce the flow of oil or to atomize it, since the oil 1s suppl ed under pressure.

The oil nozzle produces a conical centrifugal spray by means of-the valve head provided with the inclined grooves which discharge the oil along and not against the inner surface of the cylindrical bore of the discharge chamber, which has a comcal or dome shaped termination with a circular central outlet, thus avoiding abrupt change of direction and loss of velocity.

By means of the grooves arranged in groups on the valve head and in the chamber capable of being connected in various combinations or at various adjustments the oil supply can be changed or modified, and the angle of the spray can also be modified. The change in the length of the discharge chamber in the oil nozzle will vary the shape and length of the spray produced, and this is advantageous for various grades of oil. Normally the nozzle will produce a centrifugal spray, but by withdrawing the valve head will continue to operate with a straight or common jet spray, thereby avoiding shut downs in case of stoppage of the centrifugal passages. All adjustments can be made independently of each other and while the burner is in operation, and it will be noticed that the valve head is without a cleaning point or other projections into the discharge chamber, which points or projections tend to cause fuel oil, particularly if heavy, to cling to them and to emerge from the outlet in the form of a small twisting stream instead of a conical whirling spray. My

nozzle permits the oil to pass from the outlet at a wide angle to the axis thus insuring immediate mixture with the air and quick combustion. 'As shown the air cap is adjustable axially, for regulating the point of combustion, and is provided with a dampercap as described, whereby additional outlet capacities for any given axial position of the air cap may be obtained to take care of the increased volume of air due to increased duty or to expansion of the air from preheating.

Various other advantages will be apparent to those skilled in the art, and the invention is not limited to the particular construction 7 shown but may be varied in numerous ways within the scope of the following claims.

I claim:

1. An oil burner comprising a' body having an inner air tube, and an annular chamber, to which heated fluid may be supplied, surrounding said tube, said tube and chamber having outlet openings at the front, and a central oil tube projecting into and spaced from the wall of said inner tube and having a nozzle at its front end adapted to discharge oil into the air delivered from said openings and a damper cap mounted on the front end of and controlling the discharge from said annular'chamber.

2. An oil burner comprising a body the rear wall of which is involuted to form a central forwardly extending air tube and a. surrounding annular chamber, said chamber and tubev having concentric axially directed outlets at the front, an adjustable cap at the front of said chamber and cooperating with the front end of the tube to vary the outlet from the chamber, and an oil tube spaced within said air tube and having a spray nozzle at its front end.

3. an oil burner, an oil tube having a nozzle at its front end provided with a chamber therein and a jet orifice from said chamber, the wall of the chamber being grooved, and a. rotary valve' stem in said tube, having a head with grooves which may be registered with the grooves inthe chamber to control the supply of oil thereto.

4. In an oil burner, an oil tube having a nozzle at its front end provided with a chamber therein and a jet orifice from said chamber, the wall of the chamber being grooved,

and a rotary valve stem in said tube, having a head with groovz's which may be registered with the grooves in the chamber to control the supply of oilthereto the grooves in the head being inclined at their front ends to cause whirling of the oil jet.

5. In an oil burner, an oil tube having a nozzle at its front end rovided with a jet orifice, a chamber behin said orifice, and a valve seat behind said chamber, and a valve stem adjustable axially in said tube and having a grooved head fitting in the chamber and a valve face behind the head, and cooperating with said seat.

6. In an oil burner, an oil tube having a nozzle at its front end provided with a jet orifice, a chamber behind said orifice, and a valve seat behind said chamber, and a valve stem adjustable axially in said tube and having a grooved head fitting in the chamber and a valve face behind the head, and cooperating with said seat the grooves in the head being inclined to produce a whirling jet.

7. In an oil burner, the combination with a burner having an air tube open at its near end and a bracket behind said tube, of an oil tube projecting into the air tube and provided with a jet nozzle at its front end, and a needle valve mounted in the oil tube, said oil tube being removably mounted in said bracket, and removable bodily with its nozzle and valve from the air tube.

8. In an oil burner, an oil tube having a jet nozzle at its front end and a chamber in saidnozzle having grooves in its side wall, and a valve stem in the tube, having a head fitting and rotatable in said chamber, the head having groups of grooves therein which may be selectively registered with the grooves in the chamber by rotation of the stem.

9. In an oil burner, an oil tube having a jet nozzle at its front end and a chamber in said nozzle having grooves in its side wall, and a valve stem in the tube, having a head fitting and rotatable in said chamber, the head having-groups of grooves therein which may be selectively registered with the grooves in the chamber by rotation of the stem the grooves of one group being inclined to produce a whirling jet.

10. An oil burner comprising a central o-il jet nozzle, a body having an air tube surrounding said nozzle, a hot air chamber surrounding said tube, said tube and chamber having concentric outlets around the jet noz 'zle, a cap provided with outlet openings at the front of said chamber, and a rotary damper plate mounted on the front face of the cap and provided with openings which may be registered with the openings in the cap.

11. An oil burner comprising a central oil jet nozzle, a body having an air tube surrounding said nozzle, a hot air chamber surrounding said tube, said tube and chamber having concentric outlets around the jet nozzle, a cap provided with outlet openings at the front of said chamber, and a rotary damper plate mounted on the front face of the cap and provided with openings which may be registered with the openings in the cap said damper plate having an axially inclined flange projecting in front of its openings, to direct air toward the central jet.

12. An oil burner comprising a' central oil jet nozzle, a body having a central air tube open at its rear end .and surroundin and spaced from 'saidnozzle, the front cut of the tube being contracted to a c'ntral outlet opening directly in front of the 'et nozzle, said body also having an annuiar chamber surrounding said air tube, and a cap on the front of said chamber, having a wall cooperating with the contacted part of the air tube to form an annular outlet, said cap being adjustable axially to vary the size of said outlet.

In testimony whereof, I affix my signature in presence of two Witnesses.

LEON H. BRADY.

Witnesses:

Jon A. BOMMHARDI, G. V ROSENBERG.

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