US2086608A - Combustion device - Google Patents

Description

July 13, 1937. R. s. DETLOR COMBUSTION DEVICE Filed Oct. 25, 1933 INVENTOR: QJOQedn/ DY. ATTORNEY FIGS.

Patented July 13, 1937 PATENT OFFICE COMBUSTION DEVICE Robert Sydney Detlor, Westmount, Quebec, Canada Application October 25, 1933, Serial No. 695,067

5 Claims.

The inventionrelates to combustion devices, as described ,in the present specification and illustrated in the accompanying drawing that forms partof the same.

- The invention consists essentially in providing a constantly burning safety ignition burner for theiignition of unconsumed combustible gases in a furnace using solid fuel and in the supplying of, supplementary air and gas to the burner to maintain theburner flame against the smothering Ielfect offthe unconsumed combustible gases for their ignition and in the controlling of the forced draft means and the supplementary air and gas in accordance with the condition of the combustible gases within the furnace.

'Ilhe objects .of the invention are to maintain a constantly burning ignition burn-er within the combustion chamber of a furnace burning hard fuel and to automatically increase the burner flame against the accumulation of unconsumed combustible gases above the fire bed for the ignition' of these gases before they pass beyond the range of the ignition burner, to maintain the constant andefiicient ignition of the combustible 1, gases over the fire bed of the hard fuel, to control the starting and stopping of the blower motor of the forced air feed means through the action of the thermostatic switch which is responsive to the ignition burner and to the temperature of the gases within the combustion chamber and generally to provide an ignition burner which will function at all times to maintain the fire clear burning and free of smoke and to contribute to the safety of operationbythe supply of supplementary air and oxygen to the unconsumed gasesfor their prompt and efficient ignition.

' -In"the'drawing, Figure 1 is a longitudinal sectional view of the gas'burner constituting a pilot light and a torch and showing its attachment to thewall of the furnace.

:jFigure '2 is an end elevational view of the burner; showing the attachment thereof to the wall of the furnace.

Figure 3 is a detail of the projecting cap from the furnace wall, showing the tubular gas and air passage broken away.

Figure 4 is a sectional detail of the electrical make and break of connections for emergency use. "Figure 5 is an'elevational detail showing the complete device as applied to a furnace fire box, and the firebox and blower chamber in section. wLike-numerals of reference indicate corresponding pa-rts in'the various figures. -Referring to the drawingthe fire box of the furnacerisindicated=by the numeral I 5 and is shown with the bed of hard fuel IS on the grate l1 over the ash pit 20. An electrically operated blower l8 has the blower chamber l9 opening into the wall 2| of the furnace into the ash pit 26.

Above the level of the fuel bed It the ignition 5 burner has the tubular member 22 extending into the combustion chamber from the coupling 23 which is screw threaded into the furnace wall and extends on either side therefrom. The tube 22 is elbowed at 24 and projects along the wall 2| of the furnace. A flaring inlet casing 30 is mounted on the outer extension of the coupling 23 and has ,the closing cap 3| having a central screwed aperture. An inner tubular member 25 forms with the tubular member 22 an annular supplementary air passage 26 extending from the inlet casing 30 to near the mouth of the tube 22. The tubular member 25 is mounted in the central aperture of the closure cup 3| and extends outwardly therefrom and has the closure cup 32. A gas tube 21 is mounted at its outer end in the closure cap 32 of the tube 25 and extends therethrough to within a short distance of the inner end of the tube 25, and has a closed end with the aperture 29 forming a burner tip, the gas tube 2,! with the tube 25 forms the annular normal air passage feeding air from the inlet 33 beyond the closure cap 3! to the burner tip 29, this gas tube 21 is connected with the gas valve 49 which is shown with the leak hole 59 Which allows for the normal flame of the gas burner tip 29 while the valve itself remains closed.

A pipe connection leads from the inlet casing 30 through the closure cap 3| to the blower chainber I9 and allows for the passage of the supplemental air to the burner tip 29 when the blower is in operation.

On the upper surface of the extreme end of the tubular member 22 a casing or box 4| is mounted and provides an enclosure for the ther- 4 mostatic switch mechanism controlling the supplementary gas supply and the operation of the blower fan motor, and which consists of the bimetallic thermostat 34 mounted on the block 43 and having the extension 44 leading into the 4 path of the burner flame and at its other end connected to the switch arm 35 supporting the contact 36, the switch arm 35 is extended to reach between the forked ends of the magnet 41'! mounted on the bracket 42 and when the switch is open this arm 35 is normally midway between the arms of the magnet.

A screw 51 is inserted through the wall of the box 4i and has a reduced side, and when turned will force the switch arm upwards and away from contact with the lower arm of the magnet 40.

The coacting contact 31 is mounted in the inside of the box 48 immediately above the contact 36. The wires 38 and 39 lead from the contacts 36 and 3 respectively and are passed through an aperture in the wall of the tubular member 22 into the annular passage 26 and through the closure cap 3!.

The wiring 38 and 39 from the contacts 36 and 37 isthen led to the base 46 where they join with the main circuit and connection is made with the wiring 41 which may have connections to thermostatic appliances in the other parts of the building.

The electric circuit is controlled by the switch 56 and has the leads to the blower motor 48 and to the wiring 54 leading to the transformer 55 and the electric magnet 53 which when energized co-acts with the contact 52 on the lever 5| which operates the gas cock 49.

In the operation of the invention, the usual practice is to attach this combustion device through the door frame of a furnace, though it may be projected through the wall of the furnace anywhere above the fire bed.

When the furnace has been stoked up and is more or less black on top, the combustible gases being given off are not ignited in the usual way by the body of the fire, and if allowed to accumulate in the fire box they will smother a pilot light and in time explode and cause a great deal of damage and may result in the serious injury to life.

Under these conditions with this invention the bi-metal thermostat functions under the effect of reduced temperature in the firebox to bring the contacts 36 and 31 together thereby completing the circuit from the switch 56 to the electric motor 48 of the blower I8 and to the electric magnet 53 and closing the contact 52.

The closing of the contact 52 rotates the gas valve 49 allowing a full flow of gas to the burner tip 29 and with the electric motor driving the blower IS an additional supply of air from the chamber i9 is delivered through the pipe 45 into the annular passage 26.

The additional gas and air now supplied makes the ignition burner a torch with a full flame to counteract the smothering effect of the accumulating combustible gases, and ignites these gases before they have a chance to do any damage, and the burner keeps in this condition until the fire is burning bright and strong enough to ignite all of the gases from its own flame.

When the fire is burning brightly and the temperature within the firebox increases, the effect of the increased temperature on the bi-metal thermostat is to separate the contacts 36 and 31 and thereby cut out the blower motor and deenergize the electric magnet 53 allowing the gas valve lever 5| to fall back and the valve 49 to close, leaving only the small flow of gas through the leak hole 5 I.

This small flow of gas through the leak hole 5| together with the natural flow of air through the inlet 33 in the pipe 25 is sufficient to ensure a steady flame of sufllcient proportions for normal burning of the combustible gases.

When there is any tendency of the contacts 36 and 31 to stick together, the magnet 40 will exert a pull on the arm 35 and assist the bi-metal thermostat 34 to separate the contacts.

The screw 5'! acts against the bi-metal thermostat 34 in the opposite direction and. forces the contact 36 towards the contact 31.

What I claim is:

1. In a combustion device, a furnace casing, a fire box therein adapted to contain a bed of solid fuel, a motor driven blower directed at the under side of said fuel bed, and an ignition burner introduced into said furnace above said fuel bed and having an air inlet aperture, a pipe connecting said burner with a source of gas supply, a valve introduced in said pipe and having a leak hole therethrough, a supplementary air inlet in said burner, a pipe connecting said supplementary inlet with said blower, and a thermostatic means operable by said burner to open said gas valve and to start said blower motor to increase the flame of said burner.

2. In a combustion device, a furnace casing, a

fire box therein adapted to contain a bed of solid fuel, a motor driven blower directed to the under side of said fuel bed, an ignition burner introduced into said furnace above said fuel bed and having a gas passage and a pair of air passages for natural draft and supplementary air respectively, a pipe connecting said gas passage with a source of gas supply, a valve introduced in said pipe having a leak hole therethrough, a pipe conmeeting said blower with the supplementary air passage of said burner, and thermostatic means operable by said burner to open said gas valve and start said blower motor to increase the flow of gas and air to enlarge the flame from said burner.

3. In a combustion device, a furnace casing, a fire box therein adapted to contain a bed of solid fuel, a motor driven blower directed to the underside of said fuel bed, an ignition burner introduced into said furnace above said fuel bed and having a plurality of concentric tubes spaced to direct air in annular streams around a central gas tube, one of which has an aperture opening to the atmosphere, and a pipe connection from v the other of said tubes connected to said blower,

4. In a combustion device, a furnace, a fire box therein adapted to contain a bed of solid fuel, a

motor drivenblower directed to the underside of said fuel bed, an ignition burner introduced into said furnace above said fuel bed and having a connection to a source of gas supply and to a motor operated forced draft blower, an electromagnetically operated valve introduced in said gas connection, a thermostatic bi-metal switch situated at the mouth of said ignition burner and heated thereby, an electric circuit including said valve and said blower motor and said switch and adapted to be energized by closing of said switch through contraction of the thermostat bi-metal, to open said valve and energize said motor and increase the flame of said burner.

5. In a combustion device, a furnace, a firebox therein adapted to contain a bed of solid-fuel, a motor driven blower directed to the underside of said fuel bed, an ignition burner introduced into said furnace above said fuel bed and having a pipe connection ,to a source of gas supply, an electro-magnetically operated valve introduced in said gas connection, a pipe connection between said blower and said ignition burner, a switch having a pair of separable contacts, a bi-metallic thermostat extended to the tip of said ignition burner and heated thereby and carrying one of said contacts, a magnet adapted to control the operation of the switch contacts, a main electric circuit having connections to said valve and said motor and said thermostat switch and adapted to energize said motor and to open said valve when the switch is closed to increase the flame of the burner when the thermostat is cooled.

ROBERT SYDNEY DETLOR.

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