US2077424A - Gas burner - Google Patents

Description

April 20, 1937. c. J. LEVEY ET AL GAS BURNER Filed Dec. 5, 1932 III Patented Apr. 20, 1937 UNITED STATES GAS BURNER Clarence J. Lovey, Park Ridge, and Edward J. Haedike, Chicago, Ill., assignors to National Machine Works, Chicago, 11]., a corporation of Illinois Application December 3, 1932, Serial No. 645,500

13 Claims.

The present invention relates to improvements in gas burners.

The primary object of the present invention resides in the provision of a novel gas burner in which the primary air of a rich air-fuel mixture and secondary air are supplied from a single pressure source.

Various general objects are to provide a new and improved gas burner which for a given size has a relatively large B. t. u. capacity, thereby resulting in a reduced size and a comparatively low cost for any given capacity; in which the proportioning of air and fuel is simplified and readily controlled; and which is particularly adapted for the use of very low forced draft pressures,

thus keeping down the cost of operation while maintaining efficient combustion.

Further objects and advantages will become apparent as the description proceeds.

In the accompanying drawing,

Figure l is a fragmentary horizontal sectional view taken along line I of Fig. 2 of a burner embodying the features of our invention.

Fig. 2 is a side elevational view of the burner,

. partially in section along line 2-2 of Fig. 1.

Fig. 3 is a fragmentary detail sectional view taken along line 3-3 of Fig. 1.

While the invention is susceptible of various modifications and alternative constructions, we have shown in the drawing and will herein describe in detail the preferred embodiment, but it is to be understood that we do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawing, the burner constituting the exemplary embodiment of the invention comprises a burner head I having primary air-fuel mixture openings or ports H and secondary air ports l2. A proportional mixer I3 is connected to the head I!) to supply a rich mixture of primary air and fuel to the burner ports H.

Preferably, the proportional mixer I3 is of the inspirator type, comprising an air induction tube I4 and a fuel nozzle having a restricted jet orifice l6 for discharging a stream of fuel under pressure as the driving fluid axially into the tube. Fuel gas under pressure is adapted to be supplied to the nozzle l5 from a suitable source (not shown) through a line H having a control valve IS with a manual operating lever l9.

The primary air to the mixer I 3 and the secondary air to the burner head In are supplied from a common source comprising a wind box or air chamber from which the inlet end of the air induction tube l4 opens, and with which the air ports H! are in communication. The wind box into which the mixer I3 discharges.

20 may be provided in any suitable form, and in the present instance is shown as comprising two closed end wall sections 2| and 22 connected into an integral unit by an intermediate wall section 23.

The air for combustion is supplied under a low pressure to the wind box 20 from a blower 24. In the present instance, the blower 24 is mounted rigidly on the wind box 20, and has an outlet duct 25 connected to a flanged opening 26 in one side of the end section 2|. To control the amount of air supplied to the chamber 20 and hence the air pressure therein, the inlet of the blower 24 for admitting air from the atmosphere is provided with a rotatably adjustable shutter 21. Thus, a single source of comparatively low pressure air is used to supply primary air for a rich mixture of air and fuel, and secondary air to complete combustion.

The gas regulating handle l9 and the air shutter 21 are mechanically connected for joint operation by means of an adjustable link 28 so that the supply of fuel and the total supply of air may be varied proportionately in accordance with the demand on the burner. The proportion may be altered by adjusting the length of the link 28.

The burner head l0 may be provided in various forms and may have ports of various shapes and arrangements depending on the requirements of the firebox for which it is intended. In its preferred form, the burner head i0 is integral with the end section 22, and is square in lateral section. The wind box 20 also is square in lateral section so as to conform in shape with the head H1. The interior of the burner head III is hollow, and serves to define a closed plenum chamber 29 which opens to the fuel mixture ports H and The outer end of the burner head H] is formed at opposite sides respectively with two spaced burner faces 30 and 3| in which the burner ports H and 12 are formed. Preferably, each face has two closely spaced vertical rows of the burner ports H. The two burner faces 30 and 3| are slightly and oppositely inclined horizontally so as to orientate the respective sets of ports II in diverging directions.

Formed in the burner head l0 and opening from the air chamber 20 through the plenum chamber 29 to the burner faces 30 and 3| respectively between the two rows of each set of burner ports H are two vertically elongated secondary air passages 32. An elongated partition member 33 tapering inwardly in width is mounted in the discharge end of each passage 32 to define two secondary air ports I2, one for each row of burner ports ll. Thus, each row of burner ports H discharges a series of jets of the primary fuel mixture in close proximity to and substantially parallel with a sheet of secondary air.

The burner is particularly adapted for a closed firebox (not shown) in which all of the air f combustion, both primary and secondary, is supplied from the air chamber 20 to the burner head l0.

5 To mount the burner in position, the end section 22 is formed with an outer peripheral mounting flange 34 adapted to be secured to the wall of the firebox.

In the preferred form of the mixer l3, the tube l I4 is a Venturi having an inlet cone 35 and a discharge cone 36. The discharge end of the tube i4 is threaded into a central opening 31 in the inner wall of the head ID in communication with the fuel chamber 29, with an outer periph l eral flange 38 on the tube turned tightly against an annular flange 39 about the opening to secure the parts in rigid assembly.

A spider 40, integral with the entrance to the inlet cone 35 and defining air inlet openings, is

formed externally with a central axial sleeve 4| in which the fuel nozzle I5 is slidably mounted.

The nozzle I5 is adjustably threaded into the inner end of a sleeve 42 integral with the end wall of the section 2|. A screw plug 43 in the outer end of the sleeve 42 is adapted to be removed to afford access to the nozzle I5 for purposes of adjustment or replacement. The fuel line I! is connected to one side of the sleeve 42.

It will be understood that the discharge of fuel under pressure through the jet orifice IE will induce the flow of a proportionate amount of air from the chamber 20 into the inlet cone 35. The air and fuel are intimately mixed in the discharge cone 36, and the resulting primary fuel mixture passes to the plenum chamber 29 from where it is discharged through the burner ports H. The amount of fuel mixture supplied is under the control of the fuel valve l9. To control the airfuel ratio of the mixer l3, a rotary shutter 44 in the form of a disk is adjustably threaded onto the sleeve 4| in spaced relation across the inlet to the cone 35. A hand hole 45 in one side of the section 2| is normally closed, but may be opened to afford access to the shutter 44 for purposes of 45 adjustment.

Supplying all the air for combustion from a single regulated source insures an accurate airfuel ratio at all rates of combustion. The required amount of air for complete combustion, with a small excess if desired, is supplied to the wind box 20. A portion of the air enters the mixer-l'3. The balance is discharged as secondary air through the ports l2. Slight changes in the ratio of primary air to fuel are automatically compensated for by corresponding changes in the quantity of a secondary air made available. If, for example, the amount of air in the primary fuel mixture should increase, the secondary air available at the air ports l2 would be proportionately reduced due to the corresponding drop in pressure in the chamber 20. Thus, the airfuel ratio control is simple and accurate, and assures efiicient combustion.

\ By reason of the supply of both primary and secondary air under a slight pressure, thus constituting the burner one of the blast type, the

B. t. u. discharge capacity of the burner ports II for a given size of burner is materially increased. The results in a reduction in cost and a decrease in the physical dimensions of the burner for any given capacity. The burner may be operated with a slight positive pressure in a closed firebox, and without any natural draft, thereby eliminating the seepage of air into the firebox which commonly occurs where natural draft burners are used, and which would reduce the efliciency of combustion and would be subject to variations due to changes in draft.

We claim as our invention:

1. A gas burner comprising, in combination an elongated wind box defining an air pressure chamber, a burner head rigid with one end of said box, said head having a fuel chamber and a plurality of fuel ports opening from said fuel chamber and having air ports adjacent said fuel ports and opening from said air chamber, a proportional Venturi air and fuel mixer mounted in said air chamber and discharging to said fuel chamber, said mixer having an induction air inlet in said air chamber and having a fuel nozzle, means including a regulating valve for supplying fuel to said nozzle, an airblower supported on said wind box and discharging to said air chamber, said blower having an inlet provided with an adjustable air shutter, and adjustable means mechanically interconnecting said valve and said shutter for proportionate movement.

2. A gas burner comprising, in combination, a closed wind box defining an air chamber, a burner head rigid with one end of said box, said head having a fuel chamber and a plurality of fuel ports opening from said fuel chamber and having air ports adjacent said fuel ports and opening from said air chamber between said fuel ports, a proportional air and fuel mixer mounted in said air chamber and discharging to said fuel chamber, said mixer having an induction air inlet in said air chamber, means for supplying fuel to said mixer, and an air blower supported on the top of said wind box for discharging air under pressure to said air chamber.

3. A gas burner comprising, in combination, an elongated wind box closed to the atmosphere and defining an air chamber, a burner head rigid with one end of said box, said head having a plurality of primary fuel ports and having a plurality of secondary air ports adjacent and opening between said fuel ports and opening from said air chamber, said ports being oriented to discharge fuel and air in a direction generally longitudinally of said box, a proportional Venturi air and fuel mixer mounted in said air chamber and discharging to said fuel ports, said mixer having an induction air inlet cone opening from said air chamber and having a fuel nozzle discharging into said cone, means including a regulating valve for supplying fuel to said nozzle, an adjustable valve for controlling the air-fuel ratio of said mixer, and an air blower rigidly supported on said wind box and connected to discharge air under pressure to said air chamber.

4. In a gas burner, a burner head comprising in combination, a body formed witha fuel chamber and with spaced oppositely inclined burner faces, two rows of alined burner ports formed in each of said faces and opening from said chamber, and two air outlets formed in each of said faces between said rows of burner ports and in respective association therewith.

5. In a gas burner, a burner head comprising, in combination, a hollow body defining a fuel chamber and having two sets of burner ports opening from said chamber, two air passages opening through said body and said chamber respectively adjacent said two sets of ports, the fuel ports of said two sets being respectively inclined to discharge fuel in diverging directions, and means in'the discharge end of each passage defining a plurality of air ports.

6. In a gas burner, a burner head comprising, in combination, a hollow body defining a fuel chamber and having two parallel linear rows of burner ports opening from said chamber, an air passage opening through said chamber between said rows of ports, the discharge end of said passage being elongated and parallel to said rows, and an elongated partition member in said discharge end defining two air ports associated respectively with said rows of ports.

7. A gas burner comprising, in combination, a closed elongated wind box having a relatively large capacity and consisting of connected end and intermediate sections, one end section being r formed with a burner head having a fuel chamber and a plurality of air discharge passages opening from said wind box through said fuel chamber, a plurality of fuel discharge ports opening from said fuel chamber at opposite sides of each air passage, a proportional Venturi air and fuel mixer located in said wind box in substantial spaced relation to the longitudinal walls thereof, and having an expanding cone supported by said one end section and discharging to said fuel chamber, said mixer also having an inlet cone opening to said wind box and a nozzle mounted in the other end section and discharging axially into said inlet cone and supporting said inlet cone, a valve adjustably mounted on said nozzle for controlling the effective air inlet area of said inlet cone, a fuel line connected to said nozzle and including a fuel regulating valve, an air blower mounted on said wind box and discharging thereto in the region of said inlet cone, said blower having an inlet provided with an adjustable control shutter, and adjustable means mechanically interconnecting said fuel regulating valve and said shutter for proportionate movement.

8. In a gas burner, a burner head comprising, in combination, a hollow body defining a fuel chamber and having a plurality of sets of parallel rows of burner ports opening from said chamber, a plurality of air passages opening through said body and said chamber and associated respectively with said sets of burner ports, each passage having an elongated discharge end parallel to and opening between the rows of burner ports of the associated set, and a plurality of elongated partition members disposed respectively in the discharge ends of said air passages to define two elongated parallel air ports, said partition members being tapered inwardly.

9. A gas burner comprising, in combination, a closed wind box defining an air chamber, a burner head rigid with one end of said box, said head having a fuel chamber and a plurality of fuel ports opening from said fuel chamber and having air ports adjacent said fuel ports and opening from said air chamber at one side of said fuel ports, a proportional air and fuel mixer mounted in said air chamber and discharging to said fuel chamber, said mixer having an induction air inlet in said air chamber, means for supplying fuel to said mixer, an air blower supported on said wind box for discharging air under pressure to said air chamber, and regulating means for maintaining an adjustable ratio between the amount of fuel supplied to said mixer and the amount of air supplied to said air chamber.

10. A unitary forced-draft gas burner comprising, in combination, an elongated wind box closed 7 at one end by a burner head having a pluralityof juxtaposed air and fuel mixture discharge openings and adapted to be inserted substantially horizontally into a combustion chamber, said box defining a closed air pressure chamber directly in communication with the air discharge openings, proportional air and fuel mixing means mounted within said chamber and having an air induction inlet open to said chamber, a fuel nozzle discharging into said inlet, and an outlet in communication with said fuel mixture discharge openings, means for supplying gaseous fuel to said nozzle, an air blower rigidly mounted on said box for supplying air under pressure to said chamber, and adjustable control means for effecting the supply of fuel and air respectively to said nozzle and said chamber in a predetermined ratio.

11. A unitary forced-draft gas burner comprising, in combination, a wind box having end walls and defining an air pressure chamber, one end wall constituting a burner head with discharge openings adapted to receive secondary air directly from said chamber, a proportional air and fuel mixer mounted within said chamber, said mixer having an air induction inlet open to said chamber, a discharge tube rigidly supported by said one wall for supplying fuel to said head for discharge therefrom in a direction generally longitudinally of said inlet and discharge tube, and a fuel nozzle discharging into said inlet and supported by the other of said end walls, means including a control valve for supplying fuel to said nozzle, and a blower rigidly connected to said wind box to form a unitary structure therewith and for supplying air under pressure to said chamber.

12. A gas burner comprising, in combination with a closed wind box defining an air chamber, a burner head rigid with one end of said box, said head having a plurality of fuel ports and having air ports opening from said chamber between said fuel ports, proportional air and fuel mixing means mounted in said air chamber and discharging to said fuel ports, said mixing means having air induction inlet means in said air chamber, means for supplying fuel to said mixing means, an air blower supported on said wind box for discharging air under pressure to said air chamber, and regulating means for maintaining an adjustable ratio between the amount of fuel supplied to said mixing means and the amount of air supplied to said air chamber.

13. A unitary forced-draft gas burner comprising, in combination, a wind box defining an air pressure chamber and having a burner head closing one end of said chamber and a wall closing the other end of said chamber, said head having a plurality of pairs of individual air and fuel mixture discharge openings and having air outlets disposed respectively between the openings of said pairs and adapted to receive secondary air from said chamber, air and fuel mixing means mounted within said chamber and adapted to receive air therefrom and rigidly connected to said head for supplying fuel to said openings for discharge therefrom in a direction generally longitudinally of said box, means including adjustable volume control means for supplying fuel to said mixing means and opening through said wall, and a blower rigidly connected to said wind box to form a unitary structure therewith and for supplying air under pressure to said chamber.

CLARENCE J. LEVEY. EDWARD J. HAEDIKE.

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