US2283819A - Oil burner - Google Patents

Description

May 19, 1942- E. J. Y. RUTHEfiF'ORD OIL BURNER Filed July 31, 1940 2 Sheets-Sheet 1 May 1942; E. J. Y. RUTHERFORD OIL BURNER Filed July 31, 1940 2 Sheets-Sheet 2 Patented May 19, 1942 OIL BURNER Edward James Young Rutherford, Chesham Bois,

' England Application July 31, l9 40,Serial No. 348,867 In Great Britain August 10, 1939 4 Claims.-

This inyention relates to liquid fuel burners of the type in which the fuel is atomized by a jet of fluid, for example steam generated in a flash boiler heated by the flame of the burner.

The main object of the invention is to provide an improved burner of this type in which partial atomization is supplemented by open vaporization, the latter being dependent on natural draft.

Another object is to provide an improved burner suitable especially for relatively heavy fuels, such as petroleum residuals or high-boiling distillates, and capable of silent and efiicient operation in small sizes, as for domestic cooking purposes, though applicable also to the firing of boiler furnaces and the like. Silent operation is secured by effecting only partial atomization with a low-pressure atomizing agent, leaving the vaporization to be completed by heat.

Other objects and advantages of the invention will be apparent from the following description of a preferred embodiment, in which:

Fig. 1 illustrates in part-sectional elevation an oil-fired cooking range provided with the improved burner.

Fig. 2 is a sectional elevation of the burner on a larger scale, showing the upper portion of the vaporizing chamber.

Fig. 3 is a plan of the burner head, as seen in Fig. 2. g

Referring to Fig. 1 the cooking range comprises a casing a. having a hot plate I) and an oven 0, both heated by the burner 01; the hot gases entering through a substantially horizontal passage e travel up a vertical flue I, along beneath the hot plate I) and around the oven 0, being then led at the back of the casing a to a chimney g under natural draft. The burner d, which is attached to the side of the casing adjacent to the passage e, comprises a main chamber d formed by a vertical tube of frustoconical internal shape, made of fire-clay or other refractory material and encased in a sheet metal cover, the lower portion being moulded or cast with a horizontal air inlet :1 on one side and a lateral outlet d leading to the horizontal passage e on the opposite side; the top of the chamber has a central vertical passage h (see Fig. 2) with the fuel nozzle z arranged approximately horizontally and radially in relation to the pas-' sage, while the nozzle :1 for the atomizing agent is arranged vertically and in line with the axis of the chamber. The liquid fuel is fed by gravity to the fuel nozzle from an overhead tank is, preferably situated outside the kitchen or galley, by way of a filter k and a pipe k controlled by a regulating valve k The atomizing agent used in the present instance is low-pressure steam generated in a flash boiler consisting for example of a double tube 1 of the Field type arranged inside the vertical .generator.

chamber d and close to one of the sid walls; the water supply from a second overhead tank m, preferably situated directly above the cooking range, is connected through a pipe m and a regulating or shut-off valve m to the top of the inner member of the Field tube, the steam pressure corresponding to the height of the water. level in the tank m, for example 5 feet, above the The outlet from the generator vis coupled to the atomizing fluid nozzle 7' by an internal passage in a burner head or fitting a mounted on the top of the chamber d this fitting n conveniently providing a liner for the passage h and also supporting the two nozzles 21;, as well as the several pipes or tubes is, Z and m and a branch connection 0 toan air.- supply for starting purposes.

The main air inlet 11 which may be controlled by a pivoted flap or damper dlflis preferably raised above the'floor or bottom of the vertical chamber (P, with a slight drop at a step d between the lower inner edge of the inlet and the level of the floor. The floor itself may slope downwardly and at a small inclination from the side at which the main air is admitted, towards shallow port, extending around a part of the circumference of the chamber, and connecting up with the interior of the horizontal passage e, which is of approximately rectangular cross sec tion at its connection with the sloping floor of the chamber d As shown more clearly in Figs. 2 and 3, the steam generator Z, consisting for example of a close-ended tube of half-inch external diameter with an inner tube. Z of one eighth of an inch external diameter, is carried by a bridge-piece p detachably secured to the burner head by means of a clamping stirrup q pivotally attached to lugs n on opposite sides of the fitting n and having a screw q adapted to engage the bridge-piece in line with its lateral connection n leading to the nozzle 7'; the steam generator can thus be detached for inspection or attention without disturbing other parts of the burner, and when replacing the steam generator the correct position of the bridge-piece is ensured by a dowel pin n in line with the air-supply branch 0. The connection n opens into a separator chamber 7' enclosing a perforated metal screen or gauze 7 through which the steam passes to the nozzle; a clearing rod or pricker r, operated by an external handle T is movable axially in the chamber 7' for the purpose of clearing the steam nozzle when necessary. The nozzle is detachably mounted in the base of the chamber i its pro- J'ecting lower end being fitted with one or more adjustable washer plates 9' for regulating the admission of air through lateral openings h is then opened, and the atomized fuel burns within the chamber d until a sufiicient temperature is reached. The Water supply valve m is then opened and the steam generated in the flash boiler Z will take over the duty of atomizing agent, causing the fuel to become partially atomized as it falls down inside the vertical chamber d while the heat provided by the refractory walls of the chamber tends to vaporize the fuel, reducing the atomized particles to the condition of mist or vapour. It will be understood that in normal operation there is only partial combustion of the fuel inside the chamher al the air pump or other supply to the branch being put out of action and the passage h in the top of the chamber admitting only a minimum quantity of air, regulated by the washer plates f sufficient to break any vacuum and to prevent back-eddying of the atomized fuel delivered from the nozzle 1', and also to support the limited combustion required for maintaining the working temperature.

At the bottom of the chamber d the atomized and vaporized fuel comes into intimate mixture with the main air supply admitted by the lateral inlet (1 this air being drawn across the bottom of the chamber due to the draft induced by the chimney g; the air thus meets the atomized and partiallyburnt products descending from the vertical chamber, and practically completes the combustion within the burner mouth 6, from which the flame is directed into the vertical flue 1.

Any unatomized fuel dropping onto the floor of the chamber (1 will be vaporized by the heat of the refractory material and caught up by the air current for complete combustion, the liquid lying on the bottom of the chamber being shielded from the incoming cold air by the step d which gives a slightdrop of level to the floor, so that the fuel will not be blown away in liquid form by direct exposure to the air current.

In portable burners and other apparatus subject to vibration, where the use of fireclay is undesirable, the chamber d may be formed by a metallic tube or pressing of non-oxidizing metal, with an insulating airspace around the said chamber and inside the sheet metal cover.

What I claim is:

1. An oil burner comprising a substantially vertical chamber, said chamber having refractory walls and bottom and being provided with an aperture near its top end and openings on opposite sides near its bottom end, a nozzle arranged in line with the axis of said aperture, a fuel nozzle arranged within said aperture and below said first-mentioned nozzle, for supplying liquid fuel to said fuel nozzle, a flash boiler mounted within said chamber, a burner head fitting mounted upon the top of said chamber, said burner head fitting providing a liner for said aperture and supporting said nozzles, a tubular member detachably mounted upon said burner head fitting, a screw-provided stirrup clan'mina said tubular member to said burner head fitting, said tubular member supporting and connected to said flash boiler, means for supplying water to said flash boiler, and means for passing steam from said flash boiler to said first-mentioned nozzle, said steam-passing means including a spigot and socket connection between said tubular member and said burner head fitting, and said spigot and socket connection being in line with the screw of said clamping stirrup.

2. An oil burner comprising a vaporizing chamber, said chamber having substantially vertical refractory walls and a refractory bottom and being provided with an aperture at its top end and openings on opposite sides near its bottom end, one of said openings having communication with the atmosphere, a flue connected to the other of said openings, a nozzle arranged in line with the axis of said aperture, a fuel nozzle arranged within said aperture and below said first mentioned nozzle, means for supplying liquid fuel to said fuel nozzle, a flash boiler mounted within said vaporizing chamber and adjacent to a substantially vertical wall thereof, means for supplying water to said flash boiler, and means for passing steam from said flash boiler to said first mentioned nozzle for subdividing the fuel delivered by said fuel nozzle at the top end' of said vaporizing chamber, said one opening admitting air at atmospheric pressure and said other opening forming a lateral outlet for combustion of the fuel vaporized within said chamber with air admitted through the first-mentioned opening by natural draft to said flue.

3. An oil burner comprising a heat-retaining chamber having an aperture at its top end, an atmospheric air inlet and a lateral outlet both near its bottom end, said air inlet and lateral outlet being on opposite sides of said chamber, a fiue in connection with said lateral outlet, a nozzle arranged in line with the axis of said aperture, means for supplying a low-pressure atomizing agent to said nozzle, a fuel nozzle arranged within said aperture and below said first-mentioned nozzle, and means for supplying liquid fuel to, said fuel nozzle, said liquid fuel being subdivided by said atomizing agent at the top end of said chamber, vaporized by heat within said chamber before reaching the bottom end of said chamber, and finally burnt at said lateral outlet with air drawn through said air inlet by natural draft to said flue.

4. An oil burner comprising a heat-retaining chamber having an aperture at its top end, a main air inlet and a lateral outlet both near its bottom end, a flue connected to said lateral outlet, a nozzle arranged in line with the axis of said aperture but leaving a passage for admission of air to said aperture around said nozzle, means for supplying an atomizing agent to said nozzle, adjustable means for controlling the admission of air through said passage, a fuel nozzle arrangedwithin said aperture and below said first-mentioned nozzle, and means for supplying liquid fuel to said fuel nozzle, said liquid fuel being subdivided by said atomizing agent at the top end of said chamber in association with air admitted through said passage and being subsequently vaporized by heat with partial combustion within the lower part of said chamber, atmospheric air being drawn through said main air inlet by natural draft to said flue for completion of combustion at said lateral outlet.

EDWARD JAMES YOUNG RUTHERFORD.

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