US2494394A

US2494394A - Heating apparatus and fuel flow controlling means therefor

Info

Publication number: US2494394A
Authority: US
Inventors: Walter S Landon
Original assignee: Detroit Lubricator Co
Current assignee: Detroit Lubricator Co
Priority date: 1943-10-11
Filing date: 1943-10-11
Publication date: 1950-01-10
Anticipated expiration: 1967-01-10

Description

Jan. 10, 1950 w. s. LANDON 2,494,394

HEATING APPARATUS AND FUEL ELow coNTRoLLrNG MEANS THEREFoR Filed oct. 11, 194s Fla-I 2 5f 25E' INVENTOR 45 25 www'. ,J

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.ALL ATTORNEY Patented Jan. l0, 1950 HEATING APPARATUS AND FUEL FLOW CONTROLLING MEANS THEREFOB Walter S. Landon, Detroit, Mich., assignor to Detroit Lubricator Company, Detroit, Mich., a corporation of Michigan Application october 11, 1943, sci-m No. 505,744

7 Claims. (Cl. 158-36) My invention relates to new and useful improvements in heating apparatus and more particularly to means for controlling the supply of liquid fuel to a heating apparatus having a main burner and a pilot burner.

An object of the invention is to provide means to increase the ow of fuel to the pilot burner upon supply of fuel to the main burner.

Another object is to provide means to determine the maximum supply of fuel to the pilot burner.

Another object is to provide means to regulate the flow of fuel to the pilot burner and tothe main burner.

Another object is to provide means to determine the maximum flow of fuel to the pilot burner by the regulating means at which fuel will be initially supplied to the main burner.

Another object is to provide cleaning means for the means for supplying fuel to the pilot burner.

Another object is to provide safety means for stopping the supply of fuel upon failure of combustion in either the main burner or the pilot burner.

The invention consists in the arrangement and cooperative relation of parts and in the heating apparatus control effected or accomplished by such parts, all to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings to be taken as a part of this specification there are fully and clearly illustrated several preferred embodiments of the invention, in which drawings:

Figure 1 is a view of part of a heating apparatus in .vertical central section and having operatively connected thereto one control means of this invention and shown partly in vertical section and partly in elevation;

Fig. 1 is a detail view of the overcenter lever trip mechanism shown in Fig. 1,

Fig. 2 is an enlarged detail view in section on the line 2-2 of Fig. 1;

Fig. 2 is a detail plan view of the adjustment knob and high-nre and pilot iire stops shown in Fig. 2,

Fig. 3 is an enlarged detail view in section that in Fig. 1 and having operatively connected thereto another form of control means.

Referring to the drawings by characters of reference, I designates generally the main liquid fuel burner, preferably of the pot type, of a heating apparatus having a liquid fuel pilot burner 2, also preferably of the pot type. The main burner I has a bottom wall 3 with a. central opening or aperture l therethrough which is surrounded by an oil retaining ring or wall 5 cooperable with the cylindrical burner side wall 8 to provide an annular fuel receiving space or pan 1. The side wall 6 is provided with a plurality of rows of combustion air supply ports 8. The top wall of the burner I has a burner opening 9. 'I'he pilot burner 2 is positioned beneath the opening 4 in registry therewith and preferably has the upper edge of its side wall I0 engaging the under side of the main burner bottom wall 3 so that the flame from the pilot burner 2 will discharge upwardly through the opening 4 into the main burner I for igniting the fuel in the pan 1. The side wall I0 has a plurality of rows of combustion air supply ports I I. The pilot burner bottom wall I2 cooperates with the side wall Il! to provide an oil receiving pan or space I3.l

Opening through and secured in an aperture in the main burner side wall 6 adjacent the bottom wall 3, there is a fuel supply pipe or conduit I4 which extends laterally and preferably horizontally to an upright, preferably vertical, main fuel supply conduit or pipe, generally designated I5. The conduit I 4 is connected into the conduit I5 by means of the side opening of a T-iltting I6 having its alined openings vertically positioned and connected respectively to an upper pipe Il and a lower pipe I8. The lower end of the pipe I8 is connected into the yside opening of a T-iitting I9 which has one of its alined end openings connected to a laterally extending, substantially horizontal pilot burner fuel supply p ipe or conduit 20 which has its free end opening through and secured in an aperture in the pilotburner side wall III adjacent the bottom wall I2 for supply of fuel to the space I3. The other alined end opening of the fitting I9 .is provided with a reduction bushing 2| such that thebottom surface of the bushing bore or port is above the level of the bottom surface of the conduit 20 in order to provide a dam or partition 22 to normally direct the flow from the main conduit .I5 into the branch conduit 20. The height of the dam 22 also determines the fuel level in the pilot burner space I3 and in the branch conduit 20, say at the level indicated by line A, at which fuel will ow over the dam and through the bushing 2li. In the pipe I8 adacent its upper end there is an annular internal restriction or shoulder 23 Providing a calibrated oriiice 24 positioned a predetermined distance below the horizontal bottom surface of the fitting lateral port 25 and of the branch conduit i4 indicated by the line B such that the liquid head on orifice 24 will be limited by the outflow through port 25 and determine the maximum rate of fuel iiow through the orifice 24.

The conduit I is fed or supplied above the level of the orifice 24 with liquid fuel from a fuel supply means or device generally designated 26 capable of variably controlling the supply of fuel at constant rates. The device 26 has a constant level liquid chamber 21 in which the liquid level is maintained substantially constant by an inlet needle valve 28 operated by a float and level' mechanism 29 in a manner well known in the art. The chamber 21 is supplied with liquid fuel from any suitable source of supply such as a tank, not shown, through a pipe 30 connected into a strainer chamber 3l' from which the fuel ows to the chamber inlet port 32 controlled by the valve 28. Outow of liquid fuel from' the chamber 21 is through an aperture 33B and outlet port 35 to the conduit I5 and is controlled by a meterlng valve 33 having a V-slot 34 controlling iiow through the outlet port 35 positioned below the chamber liquid level, indicated by the line L-L of Fig. 2. The stem 36 of valve 33 has a left hand screw thread 38 of steep pitch adjustably screwthreaded in the sleeve 39 for vertically adjusting the valve 33 to control the rate of now through outlet 35. The stem 36 is provided with ahand grip and stop member or knob 40 engageable with a low or pilot fire stop member 4I and with a high fire stop member 42 for limiting rotary motion thereof. The outlet 315 opens into an inclined passageway connected at its upper end into a vertical hollow boss 43 which has its lower end screw-threadedly connected to the upper end of the pipe I 1. At the upper end of the boss 43 and alined with the orifice 24 there is a rotatable plug or supporting member 44 having a screw driver slot in its upper outer end for rotation of the plug. Secured to the lower inner end of the plug 44 and extending downward through the boss 43 and the pipe I1 and through the orifice 24 there is an orifice cleaning member or wire 45 which is bent or offset or excentrically mounted so that it will scrape -the side wall of the orice 24 upon rotation of the plug 44. The Wire 45 is preferably of polygonal cross section, say triangular as in Fig. 3, for at least that portion of its length which extends through the orifice 24. It may be noted that the wire 45 should at all times have contact with the side wall of orifice 24 so that it will not create a change in flow rate, as would be the case if it had its position, radially of the orifice 24, altered upon rotation of the plug 44.

Safety means are provided for closinggtherinlet valve 23 to shut off iiow to the mainc'duit I5 and the heating apparatus in the event of predetermined excess liquid level in the chamber 21 or upon rise of liquid level in the fitting I9 above the line A. The chamber 21 has an overflow outlet 48 which determines the maximum level permissible in chamber 21. The outlet 46 discharges into a cup 41 carried by and discharging through its bottom wall into a vertical conduit or pipe 48 which, at its lower end, is connected into one of 75 and 'pass through the pipe 50 and the outlet 5I intol lil the alined end ports of a T-iitting 49. The lateral port of fitting 49 is connected by a pipe or conduit 50 to the bore of bushing 2i so that oil iiowing into the fitting through pipe 48 or pipe 50 will be discharged downward through the other alined or bottom fitting outlet 5I. Positioned below the outlet 5I there is a bucket or container 52 which is connected by a vertical link or supporting member 53 to one end of a safety lever 54 plvotally supported as at by the control device 26. The lever 54 overlies the inlet valve 2S and is engageable therewith to positively seat the same and close the inlet 32. The lever 54 and empty container 52 are supported in inactive upper position by an overcenter spring 56. When liquid which overflows through the outlet 5I fills the bucket 52 to a predetermined value the increased Weight on the lever 54 will cause the same to pivot about pin 55 sufficiently to move the spring 56 from its overcenter position to a position overcenter in the opposite direction. In so moving, the lever 54 will engage the upper end of the valve stem 28 and the combined force of the trip bucket mechanism. the liquid therein, and the spring 56 will cause the lever 54 to positively move the valve stem 28 to closed position.

outlet 35 will be at the rate of say 2 ccs. per minute. which flow will be passed by the orifice 24 so that there will be no iiow through branch conduit I4. With the stem stop member 40 against the pilot stop member 4 I the fuel fiowing into the pilot burner space I3 is ignited by any suitable means and the heating apparatus will continue to operate at a low pilot lire. If it is desired to start the main burner I, then the stem 36 is rotated counter-clockwise away from the stop member 4I to some position, such as is shown in Fig. 1, which will open the metering valve 33 to provide a iiow through the outlet 35 at a rate greater than 4 ccs. per minute. This increased flow will result in an increasing rate of ilow through the orifice 24 as the liquid head on the orifice builds up to the line B, thereby causing an increasing rate of combustion in the pilot burner 2. When the head on orifice 24 reaches the line B the excess oil will flow through the outlet 25 and branch conduit I4 into the main burner space 1 for ignition by the increased pilot flame. The diameter of port 25 and conduit I4 is suilicient so that there will be substantially no increase of liquid level above the line B when the valve 33 is moved to full open position with the stop 4I) against the stop member 42 and therefore the rate of flow through the oririce 24 and the size of the ilame in the pilot burner 2 will be substantially unchanged for all adjustments of the valve 33 at which fuel will be fed to the main burner I. In order to assure .that a constant flow rate will be maintained to the pilot burner 2 for any setting of the valve 33, the cleaning member supporting plug 44 will occasionally be rotated so as to clear the orifice 24 of any accumulated wax or other foreign matter, the sharp edge of the wire 45 serving to scrape the side wall of the orice. If, for any reason, fuel collects in.

anche the container 52, the dam 22 limiting the height to which the liquid can collect in the space I3. When the Weight of the liquid in container 52 is sufficient to overcome the component of force of spring 5B, then the rod 53 will be pulled downward, thereby rotating the lever 54 on its fulcrum or pivot 55 to move the spring 58 overcenter, whereupon the lever 54 will be moved sharply downward into engagement with the valve 29 and close off further inflow of fuel to the chamber 21. This closure of valve 28 will stop further flow of fuel to the pilot burner 2 as soon as the liquid level in chamber 21 drops below the inlet to the outlet port 35. If the fuel supplied to the main burner I is not ignited for any reason, then, when the level of theliquid in the space 1 increases sufliciently to overflow the wall or ring 5, the overflowing fuel will discharge into the pilot burner space I3 and flow thence through the branch conduit 20 and the pipe 59 and outlet 5| into the container 52 to close off the valve 28 as above described and stop supply of fuel to the burners I and 2. In addition, if the float mechanism 29 should fail to function or if, for any other reason, the level in chamber 21 should increase above the overow outlet 46, then the excess liquid will be discharged into the container 52 and operate the safety trip mechanism to close valve 28 in the same manner as for fuel flow through pipe 59. thereby stopping the supply of fuel to the burners and 2. It will be apparent that the safety trip mechanism can be readily reset by swinging the supporting member 53 outward and tipping the container 52 to drain it of liquid fuel, whereupon the member 53 would be pushed upward to return the spring 5E to its overcenter position as shown in Fig. 1, and the container 52 repositioned beneath the outlet 5|.

Referring to Fig. 4, the control device differs from that of Fig. 1 only in the following respects. The boss 43 has its lower end changed so as to position its connection to the pipe I1 of conduit 5 in vertical alignment with the metering valve outlet 35, the upwardly inclined passageway, here designated 68, being retained to vent air to atmosphere which might collect in the pipe or conduits on the outlet side of orifice 35. The cleaning member 45 of Fig. l, here designated 5I, is secured directly to the bottom end of the metering valve 33 in any suitable manner so that the orifice 24, here designated 62, will be cleaned and have its side wall scraped to remove wax and other foreign matter on each operation of the metering valve. If it is desired to clean the orifice 62 at additional times. the

same may be done by a quick operation and return of the metering valve 33 to its desired setting. The orifice 62 is here shown as carried by and formed through an adjustable sleeve or plug 63, preferably adjustably screw threaded in the bore of the pipe I8, so that the position of the orifice relative to the bottom surface of the port 25 and branch conduit I4 can be adjusted to regulate the maximum liquid head onthe orice 62 and accordingly the maximum rate of flow of liquid fuel to the pilot burner 2. From the foregoing description of this Fig. 4, it is believed that the operation of the control device and the heating apparatus, when changed as shown in Fig. 4, will be apparent when taken in connection with the description of Fig; l. and no further description is deemed necessary.

Referring to Fig. 5, the heating apparatw:` has a main liquid fuel burner 10 of the pot type having a bottom wall 1I cooperable with a cylindri- 6 cal side wall 12 to provide a mixing chamber 18 and an oil receiving space or pan 14. Through ,the side wall 12 there are a plurality of rows of air inlet holes or ports 15 for supplying primary combustion air to the chamber 13. The burner 18 may be provided with a surrounding jacket 16 which provides an annular compressed air supply chamber 11, which may be supplied with air undery pressure by any suitable means such as a blower 81* or the like discharging into the chamber 11 through the inlet duct 18. Liquid fuel is supplied to the burner space 14 through a laterally extending and substantially horizontal conduit or pipe 19 which opens through and is secured in the wall 12 adjacent the bottom wall 1|, the conduit 19 preferably being inclined slightly downward toward the wall 1|. Extending upward into the chamber 13 there is a liquid fuel pilot burnery preferably of the pot type having a bottom wall 8| and a cylindrical side wall 82 cooperable therewith to provide a mixing chamber 83 and a liquid fuel receiving space or pan 84. The side Wall 82 is connected or joined directly to the main Vburner bottom wall 1| so that the bottom Wall 1| will be heated by conduction from the pilot burner 80. The chamber 83 is surrounded by a jacket 84 which provides an annular compressed air chamber 85 for supplying primary air to the chamber 83 through a plurality of rows of primary air inlet ports or openings 86. The chamber 85 is supplied with air under pressure through a duct 81 which may be supplied with air under pressure from a blower 81a or the like, but which preferably extends into the chamber 11 and has its open end portion or inlet 88 positioned above the level of the lowermost row of air inlet ports 15. The air supply to the duct 81 from the chamber 11 is controlled in any suitable manner as by a valve or damper 89 positioned in the duct 81 and which may be thermostatically or otherwise controlled in accordance with an increase in the fuel supply to the pilot burner. The bottom wall 1| is provided with a plurality of ports or apertures 90 so that the air supplied by the duct 81 can pass into the upper part of the chamber 85 for ow through the air supply ports 86. Liquid fuel is supplied to the pilot burner space or pan 84 through a lateral substantially horizontal conduit or pipe 9| which opens through and is secured in the side wall 82 adjacent the bottom wall 8|. The main burner fuel conduit 19 is positioned above the pilot burner fuel supply conduit 9| and these conduits extend from and are supplied with liquid fuel by an upright substantially vertical main fuel supply conduit 92. Positioned in the conduit 92 intermediate the levels of the conduits 19 and 9|, there is an annular flange or sleeve which may be adjustable as in Fig. 4 and through which'there is a calibrated fuel ow controlling orifice 93. The oriilce 93 is positioned a predetermined distance below the level of the bottom edge of the opening 94 which leads from the main conduit 92vinto the main burner conduit 19. The portion of the conduit 92 above the orifice 93 and below the bottom edge of opening 94 serves as a dam and cooperates with orifice 93 to determine the maximlun flow rate of fuel to the pilot burner and the rate of supply of fuel to the conduit 9'! at which fuel will be'supplied to the main burner 'I0 as above described in connection with 1. Liquid fuel is supplied to the main conduit 92 from the outlet 95 of a constant level liquid fuel supply device 98 which may be similar to the de- 7 vice Il of Fig. l or may be any other constant level device such as disclosed in the patent to Russel, No. 2,317,556 granted April 27, 1943, wherein safety means is included for closing the inlet valve upon occurrence of excess liquid level. The device 96 has a constant level chamber $1 discharging through the outlet 95 which is controlled by a fuel metering valve 98, such for example as shown in Fig. 1. The cleaning wire 99 for the orifice 83 may be attached to the valve I as described above in connection with Pig. 4.

The liquid level in the chamber 91 is maintained substantially constant at the line R by any suitable means, such as an overflow pipe or the float operated inlet valve mechanism as described and shown in Fig. l. The line designated S indicates the excess liquid level at which the safety mechanism will be actuated to close the inlet to chamber 91 and stop the supply of liquid fuel to the main conduit 92. The device 96 is positioned relative to the main burner 'lll so that the maximum liquid level in chamber 91, indicated by the line S, will be below the lowermost row of air inlet ports l in the main burner lll.

The operation of the apparatus and control means of Fig. 5 is as follows: Assuming that the safety trip means for the inlet valve to chamber vQl is in inactive position, that there is a source of liquid fuel connected to the chamber 91 so that the liquid level is standing at the line R, that the minimum pilot fire stop Il of Fig. 1 has been eliminated or moved so that the valve it .is closed to cut off fuel to the pilot burner 80, and that air under pressure is being supplied to the chamber 1I and the duct 81, then, upon opening the metering valve 98 to provide the minimum flow for pilot ame, fuel will discharge from the chamber `$l through outlet 95 to conduit $2 and thence through the oriilce S3 into the pilot burner space or pan 84 where it can be ignited by any suitable means. When it is desired'to ignite the main burner 10, the metering valve 98 will be moved toward open position to increase the rate of flow through the outlet 95 in excess of that which can flow through the oriilce 93 and therefore the liquid head will build up in the conduit $2 until it reaches the level of the opening or port 94 and will thereupon ilow into the main burner space or pan 14 which has had its bottom wall heated by the pilot burner-80 so that the liquid fuel in pan 'M will be readily vaporized to mix with the air under pressure supplied from chamber 'I1 through ports l5. The liquid head on the orifice 93 will increase the ilow rate to the pilot burner to a desired maximum, thereby increasing the pilot burner flame which will ignite the combustible mixture of air fuel in the chamber 13. It is desirable to increase the rate of flow of fuel to the pilot burner when the main burner is ignited in orderA to prevent the possibility of extinguishment of -the pilot burner which may result from thev operation of the main burner,

unless the pilot flame is increased. If the increased supply of fuel to the pilot burner requires additional air, then the damper 89 will be adjusted to permit an increased air flow to the chamber 8B.

What is claimed and is desired to be secured by Letters Patent of the United States is:

l. In a heating apparatus, a pilot burner, a main burner superposed on said pilot burner and having a bottom wall aperture communicating directly with the interior of said pilot burner, a lateral feed pipe for supplying liquid fuel into the base of said main burner, a lateral feed pipe for supplying liquid fuel into the base of said pilot burner, an upright pipe feeding said lateral pipes and having a flow restricting oriilce therebetween, a constant level liquid chamber having an outlet discharging into said upright pipe above said orifice, and a metering valve in said -outlet and determining the rate of fuel flow to said upright pipe, the size of said orifice determining at what rate of fuel ilow from said outlet, fuel will be backed up by said orifice and overilow into said first-named lateral pipe.

2. In a heating apparatus, a pilot burner, a main burner superposed on said pilot burner and having a bottom wall aperture communicating directly with the interior of said pilot burner, a lateral feed pipe for supplying liquid fuel into the base of said main burner, a lateral feed pipe for supplying liquid fuel into the base of said pilot burner, an upright pipe feeding said lateral pipes and having a ilow restricting orifice therebetween, a constant level liquid chamber having an outlet discharging into said upright pipe above said orifice, a metering valve in said outlet, and safety means operable after occurrence of excess liquid level in said pilot burner to cut oil flow of liquid fuel to said upright pipe.

3. In a heating apparatus, a pilot burner. a main burner superposed on said pilot burner and having a bottom wall aperture communicating directly with the interior of said pilot burner. a' lateral feed pipe for supplying liquid fuel into the base of said main burner, a lateral feed pipe for supplying liquid fuel into the base of said pilot burner, an upright pipe feeding said lateral pipes and having a flow restricting orice therebetween, a liquid fuel chamber having an outlet connected to said upright pipe above said orifice, a valve in said outlet, said orifice being operable to restrict flow to 'said pilot burner and being positioned a predetermined distance below said main burner feed pipe so that there will be a predetermined increased head of fuel on said oriilce upon operation of said valve to supply fuel to said main burner.

4. In a heating apparatus, a pilot burner, a main burner superposed on and communicating with the pilot burner, means for supplying liquid fuel to said burners comprising a constant liquid level device having an outlet, a main supply conduit connected to said outlet, a metering valve controlling said outlet and the now to said conduit, a pilot burner supplying conduit leading from said main. supply conduit to said pilot burner, a main burner supplying conduit leading from said main supply conduit to said main burner, Vsaid main supply conduit having a ilow restriction orice positioned between said supo plying conduits, and means to cut off the supply to said supply conduit, a flow restricting oriilce member" positioned in said supply conduit adjacent to but below said main conduit and operable to restrict ow through said lower conduit'upon opening of said metering valve to supply liquid to said main conduit, a valve controlling said inlet, safety means having a liquid receiving container and operable upon liquid flow into said container to close said inlet valve, and a conduit leading from said lower conduit to said container.

6. A control device comprising a constant liquid level device having a chamber with an inlet and a main outlet, a float operated valve controlling said inlet, said chamber having an overilow outlet, a metering valve controlling flow from said main outlet. a main supply conduit connected to and extending downward from said main outlet, a main conduit extending laterally from said supply conduit, a lower conduit extending laterally from said supply conduit at a point below said main conduit, said main supply conduit having a flow restricting orifice therein above the level of said lower conduit, safety trip means Ihaving a liquid receiving container and operable by weight of liquid in said container to close said iloat operated valve, a vertical discharge conduit discharging into said container and operable to receive liquid from said overflow outlet, a feed conduit connecting said lower conduit to said. discharge conduit, and a dam for said feed conduit determining the liquid level in said lower conduit at which liquid will flow through said feed conduit into said container to actuate said trip means.

7. In a heating apparatus, a main pot type liquid fuel burner having an opening through its bottom wall and having primary air inlets through its side wall spaced above its bottom wall, a pot type liquid fuel pilot burner extending into said main burner through said opening and having its side wall joined in heat conducting relation to said bottom wall, a constant level liquid fuel supply means positioned relative to said main burner such that the maximum pos- 10 sible liquid level in said supply means will be below said primary air inlets, said fuel supply means having an outlet, means to control the rate of flow from said outlet, a main fuel conduit leading from said outlet and discharging into said main burner, a fuel conduit leading from said outlet and discharging into said pilot burner, a restricted orifice means in said lastnamed conduitfand operable to restrict fuel flow from said outlet to said pilot burner, and a dam interposed between said orifice means and said main conduit and cooperable with vsaid orifice means and blocking flow to said main conduit to determine the substantially maximum rate of fuel flow to said pilot burner, said dam and said orice means cooperating with said outlet control means to determine at what minimum rate of flow from said outlet fuel will be fed to said main burner.

WALTER S. LANDON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 425,667 Fenby Apr. 15, 1890 1,109,768 Laux Sept. 8, 1914 1,377,994 Wagner May 10, 1921 1,556,817 Higgins Oct. 13, 1925 1,650,065 Dial Nov. 22, 1927 1,891,855 White et al Dec. 20, 1932 1,987,179 Chadwick Jan. 8, 1935 2,075,242 Todaro Mar. 30, 1937 2,086,884 Sherman July 13, 1937 2,247,689 Kirkpatrick July 1, 1941 2,253,056 Ullstrand Aug. 19, 1941 2,346,817 Breese et al Apr. 18, 1944 2,353,341 Klonaris July 11, 1944