US1810373A - Gas burner - Google Patents

Description

June 16; 1931. M. J. ossm's GAS BURNER Filed Jan. 2, 1929 2 Sheets-Sheet. 2

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Patented June 16, 1931 UNlTED STATES PATENT" OFFICE i g MILLABD J. ROBERTS; OFBUFFALO, NEW YORK, ASSIG-NOR TO ROBERTS-GORDON APPLIANCE CORPORATION, OF BUFFALO, NEW YORK GAS BURNER Application filed January 2, 1929. Serial No. 329,754.

This invention relates to improvements in gass burners which have been designed for use in furnaces, boilers and the like and for either; domestic or industrial purposes.

Oneof its objects is therevision of an automatically controlled gas urner which is eflic ient in operation which is not liable-to get out of order, which is reliable and positive in action, and which produces a maximum f-uampunt of heat at a minimum expenditure of e Y Another object of the invention is to so desi the burner that only the proper. proportion of secondaryair is injected for complete combustion," thereb preventing excessive temperature in the c 'mney andmcreasing the eificiency of the combustion.

A further object is to so construct the burner-that a delayed action of the secondary air.

' supply is effected when-starting, thereby pro-v ducing a noiseless burner.

Other features of the invention reside in the construction and arrangementof parts hereinafter described and particularly pointed out in the appended claims.

In the accompanying drawings: Figure 1 is a perspective viewof my improved burner showing the same installed in a round boiler or furnace. Figure 2 is an enlarged vertical section of the diaphragm for controlling the secondary air door. Figure 3 is an enlargedtop planview, partly 1n section, of the burner and itsassociated parts taken onl-ine 3-3 of Fig. 4. Figure 4: is a 'vertical longitudinal section taken on line 4.4, Figure 3. Figure fi is an'enlarged transverse vertical section of one of the sections of the burner-body taken on line 55, Fig. 3. Figure 6 is an enlarged detailed-vertical of line 6'-6, Figure'3.

Similar characters indicate corresponding section of the pilot burner, taken in the plane heating apparatus, contains a primary cham-' her for the receptionv of the gaseous mixture and a secondary chamber for receiving air to be directed at the base of the gas flame, the secondary air being delivered through an air duct installed through the ash-pit. door of the boiler and serving as a support on whictrthe burner is-mountcd and also as a housing in which the mixing tubes are arranged. I I do The burnerbody 11 may be of any desired shape and is preferably/ made in sections suitably bolted together to facilitate its installation into the heating apparatus. In its top wall the burner-body has a pluralityof outlets or openings 12 for the gaseous mixture and its interior is subdivided by a partition 13 into upper and lower chambers 14-,-

15, respectively, which preferably extend around the outer side of the burner-body, the latter being provided centrally of its lower side with a depending attaching neck or (:01- lar 16 forming an inlet passage 17 for the admission of secondary air. The upper or secondary chamber 14 communicates directly with the secondary air passage 17 while the lower or primary chamber 15 is adapted to receive the gaseous mixture, the secondary air being added to and commingling with the gaseous mixture at the outlets 12 of the so burner-body. Rising from the partition 13 into the secondary chamber 14 and opening at their lowerends into the primarychamber 15 are a pluralityof burner tubesior et's 18, which open at their upper ends at or ad jacent to the burner-outlets 12, whereby the proper proportion of air in the secondary chamber commingles with the gaseous. IIllX ture esca ing from the outer ends of the burner tu s to efl'ect-complete combustion of the gas.

The numeral 19 indicates the air duct for delivering the secondary air to the corresponding chamber 14 in the burner-body 11, this duct extending horizontally through the ash-pit opening of the heating apparatus in the manner shown in Figure 1 and its innerend terminating in an upright leg orportion 20 to the upper 'end of which the neck 16 of the burner-body is fastened, as

shown in Figure 4. ,The ash-pit opening around the duct is bricked up or otherwise sealed and the space between the burnerbody and the surrounding wall of the heating apparatus is sealed with asbestos or similar material. The outer or inlet end of the secondary air duct is exposed to the atmosphere and is controlled by a hinged door 21 which is closed when the gas supply is turned off.

The gaseous mixture is delivered to the primary chamber 15 of the burner/through the medium of one or more Venturi mixing tubes 22 preferably housed within the air duct 19. In the installation illustrated in the drawings, two of such mixing tubes have been shown arranged side by side and connected at their inner ends to tubular fittings 23 )referably cast integral with the burnerbody at opposite sides of its attaching neck 16 and communicating with said primary chamber to effect an equal distribution of the gaseous mixture thereto. The outer ends of the mixing tubes are connected to the main gas supply pipe or manifold 24, which extends transversely through the air duct, gas cocks 25 being provided for regulating the amount of gas delivered to the burner. The

air supply to these tubes may be regulated by suitable shutters 26. Access to the latter and the gas cooks for regulation may be had through an opening provided in the top of the air duct 19 and normally closed by a cover plate 27.

Interposed in the gas line 24 is a suitable pressure regulator 28 and arranged between the'latter and the branches leading to the mixing tubes 22 is a main gas control valve 29 of any suitable type. In the example shown, thisjvalve is of the electrically operated type and is included in the circuit of a thermostat (not shown), so that when the room temperature drops below normal the valve is automatically opened and when it reaches a temperature above normal the valve is closed.

An automatic safety pilot burner is employed for lighting the main burner and its preferred form is shown in Figure 6, where-.

in 30 indicates the base thereof to which its variousparts are attached and 31 indicates a sheet metal housing surrounding the same and arranged to be detachably inserted in an opening 32 in the burner-body, as seen in Figures 3 and 4, a spring clip 33 or similar device being used for holding the pilot unit in place in said opening. Rising from the base is a lava burner stem or tube 34 having apertures 35 therein and secured to the lower end of the base in communication with this tube is a mixer 36 which is connected with the gas line. Mounted on the base alongside the burner tube is an expansion element 37 carrying a porcelain pin 38 engaging a contact strip 39. fixed at its lower end to a contact screw 40. Intermediate its ends this contact strip is adapted to engage a similar contact screw 41 when the element 37 is expanded, said screws and contact strip being included in the circuit of the gas control valve 29. When the pilot burner is lighted the element 37 expands, closing the circuit across the contact screws 40, 41 and causing the gas valve 29 to be turned on in the event that the room temperature is below that at which the thermostat is set. Should the room temperature be equal to or above that point, the'circuit, while established at the contact screws, is broken at the thermostat, as is usual with such temperature-controlling devices.

The opening and closing of the door 21 to control the-admission of secondary air to the duct 19 and thence to the secondary chamber 14 of the burner is preferably accomplished automatically and the mechanism is designed to efl'ect a delayed opening of the door when the burner is started up so that the secondary air is admitted after the. gas has been allowed to ignite. To this end a diaphragmhousing or gas chamber 42 is mounted on and in communication with the gas pipe 24 and is disposed on that side of the air duct opposite to that on which the pressure regulator 28 and the gas control valve 29 are ar ranged, whereby the gas is admitted to the mixing tubes before it reaches said. housing. Disposed centrally in the chamber of the latter is a diaphragm 43 having a stem 44 extending through the top of the housing and pivotally connected to a vertically-swinging lever 45 fulcrumed on a link 46 pivoted to the housing, as shown in Figure 1. One end of this lever is'eonne'cted by a chain 47 with the door 21 of the air duct and its other end has a weight 48 mounted thereon to counterbalance the door. In its top wall the diaphragm-housing has a vent 49 to effect a gradual displacement of air therefrom when the gas is turned on and to correspondingly actuate the lever slowly to open the air duct door. By this construction, when the gas is first turned on the door 21 is closed, so that practically pure gas is ignited at the burner;

shortly thereafter this door is automatically opened by the gas pressure to admit air to the duct 19. VVhenthe gas 'is turned off, the door is automatically closed, producing a. thermos-bottle effect in the heating apparatus and preventing its cooling down.

Supported in a slightly inclined position around the top of the burner-body 11 and just inwardly of the gas outlets 12 are fire clay radiants 50, which are so designed that they are all equally distant from the gas flame and fire-pot Walls. These radiants become red hot soon after the gas is lighted and hold the heat at the burner and against the side walls of the furnace or boiler where it can most readily be absorbed. These radiants or refractory members, because of their location on the top surface of the burner, heat the top wall of the burner both because of heat conducted directly from the radiants to the top wall, and because of heat radiated from these members to the top wall. The heating of the top wallof the burner results in heating the secondary air in the chamber 14 of'the burner.

The heating of this secondary air increases materially the efiiciency of the burner.

In starting up the burner, the safety pilot is first lighted and as soon as its expansion element 37/ moves the contact strip 39 into engagement with the contact screw 41, an

electric circuit is closed to automatically effectthe opening of the gas valve 29 which delivers the fuel to the mixing tubes 22 and thence intothe primary chamber 15 of the burner where it is ignited at the openings 12 by the flame issuing from the pilot. At the start the door 21 controlling the supply of air to the duct 19 is closed, so that practically pure gas is delivered to the burner.

Subsequently, however, the gas pressure acts on the diaphragm 43 to effect a delayed opening of this door whereupon the air is ad mitted to the duct to deliver the proper amount of primary air to the mixing tubes and to also direct a supply of secondary air to the burner-chamber 14: where it is injected at the base of the gas flame to produce a high flame temperature and effect complete combustion of the gas. This air duct, which is proportioned to the amount of gas re-.

quired for the burner, acts to control, measureand direct the amount of air which passes into the burner; it prevents excessive temperature 1n the chimney; 1t increases the efficiency of production; and the excess of air introduced at the burner-openings is reduced to a minimum. When the room temperature reaches that at which the thermostat is set, thegasvalve 29 is automatically turned off and the diaphragm 43 is allowed tolower, closing the controlling door 21 of the air duct 19. Should the pilot go out, the circuit across the contact screws 40-, 4:1 is broken with the result that the gas valve is turned off, thereby eliminating any danger in the use of this improved burner.

I claim as my invention 1. A gas burner, comprising a body having a primary chamber for the gas, a secondary chamber for the air and outlets therein for the gaseous mixture, burner-tubes communicating. at their-"lower ends with said primary chamber and discharging at their upper ends adjacent said outlets, an air duct leading to said secondary chamber, means for interrupting the supply of air to said duct, and a mixing tube. for thegaseous mixture and receiving air from within said air duct and communicating at its inner end with said primary chamber.

2., A gas burner, comprising a body having a primary chamber r'or the gas, a secondary chamber for the air and outlets therein for the gaseous mixture,burner'-tubes communi eating at one end with said primary chamber and discharging at their other ends adjamunicating at its outer end with a source of gas supply and receiving primary air only from said duct, and conducting the mixture of air and gas to said primary chamber, and means for controlling the admission of air to said duct.

3. A gas burner, comprising a body having a primary chamber for the gas, a secondary chamber for the air and outlets therein for the gaseous mixture, burner-tubes communicating at one end with said primary chamber and discharging at their other ends adjacent said outlets, an air duct leading to said secondary chamber, a mixing tube for the gas and air communicating at its outer end with said duct and with a source of gas supply and at its inner end with said primary chamber, and means governed by the How of gas to the mixing tube for controlling the admission of air to said duct.

4. A gas burner having a primary chamber for a mixture of air andgas, a secondary chamber for supplying secondary air to the flame, an air duct leading to said secondary chamber, a gas supply pipe, a mixing tube to receive air therefrom and at it's other end into said primary chamber, means for regulating the amount of air delivered to the mixing tube, a movable closure forcontrolling the admission of air to said duct, and means governed by the flow of gas to said mixing tube for controlling the opening and closing of said duct-closure.

5. A gas burner, comprising a body having a primary chamber for a mixture of air and gas, a secondary chamber for supplying secondary air to the flame, an air duct'leading to said secondary chamber, a gas supply pipe,

a mixing tube communicating with said duct and with a source of gas supply and receiving primary air only from said duct, and having a. connection to the gas pipe, a movable closure for controlling the admission of air to said duct, a controlling valve in said gas pipe at one side of its connection with the mixing tube, and means for controlling the opening and closing of said duct-closure, said fire-box of the heating apparatus andcommunicating at its front end with the atmosphere, a burner having outlets therein for a. mixture of gas and primary air and having a chamber for-admitting secondary air to the flame the latter communicating with the air duct, :1 mixin tube adapted for connection tothe gas supp y and openingat its front end into said air duct to receive primary air from said duct, and at its rear end into a primary chamber, and means appliedto the front end of the air duct for controlling the supply of air thereto.

, 7. A gas burner, comprising av body having a primary chamber and asecondary chamber, an air duct leading to said secondary chamber, a. mixing tubefor the gaseous mixture communicating at its outer end with the air duct to receiveair therefrom only and at its inner end with" said primary chamber, and

trolling the admission of air thereto, a controlling valve in said gaspipe, and means for controlling the opening and closing of said duct-closure, said means including a diaphragm actuated by the pressure in the gas pipe, and connections between the diaphragm and said closure whereby a delayed opening of the latter is effected when the gas controlling valve is opened.

MILLARD J. ROBERTS.

means for controlling the passage of air to said duct.

. 8. A gas burner, comprising a body having superposed primary and secondary chambers for receiving the gaseous mixture and secondary air, respectively, an air duct leading to said secondary chamber, and a mixing tube for the gaseous mixture communicating at its outlet end with said primary chamber and at its inlet end with said air duct to receive primary air therefrom, and means for controlling the passage of air to said duct.

9. A gas burner, comprising a body having a primary chamber and a secondary chamber,

an air duct leading to said secondary chamber, I. gas supply pipe, a mixing tube in communication at one end with said gas supply pipe and the atmosphere and at its other end with said primary chamber, a movable closure applied to said air duct for controlling the admission of air thereto, automatic means for operating said closure, and means for governmg said automatic means to effect a delayed opening of said air duct closure.

10. gas burner, comprising a body having a primary chamber and a secondary chamr, an air duct leading to said secondary chamber, a gas supply pipe a mixing tube in communication atone end with said gassupply pipe and the atmosphere and at its other end with said primary chamber, a movable closure ap lied to said air duct for controlling the a mimion'of air thereto, and actuating means for said closure, said means being 'in communication with the gas pipe an governed by the pressure-therein for effecting a delayed opening action of said closure. 11. A gas burner, comprising a body hav-

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