US2690766A - Valve assembly for modulating burner control system - Google Patents

Description

Oct. 5, 1954 J. L. BREESE 2,690,766

VALVE ASSEMBLY FOR MODULATING BURNER CONTROL SYSTEM Filed Dec. 12, 1949 5 Sheets-Sheet 2 ri g 79,3 4 70 y ,17 4

m $1 k :23 73% by J. L. BREESE Oct. 5, 1954 VALVE ASSEMBLY FOR MODULATING BURNER QONTROL SYSTEM Filed D60. 12, 1949 5 Sheets-Sheet 3 06f. 4 J. L. BREESE 2,690,766

VALVE ASSEMBLY FOR MODULATING BURNER CONTROL SYSTEM Filed Dec. 12, 1949 5 Sheets-Sheet 4 QLU-----4 1770622 far .Jvmes L .Ei as J. L. BREESE Get. 5, 1954 VALVE ASSEMBLY FOR MODULATING BURNER CONTROL SYSTEM Filed Dec 12, 1949 5 Sheets-Sheet 5 Patented Oct. 5, 1954 VALVE ASSEMBLY FOR MODULATIN G BURNER CONTROL SYSTEM James L. Breese, Santa Fe, N. Mex., assignor to Breese Burners, Inc., Santa Fe, N. Mex, a corporation of Delaware Application December 12, 1949, Serial No. 132,531

7 Claims.

My invention relates to a modulating system for .oil burners andhas for one purpose to provide an improved valve assembly.

Another purpose is to provide an improved valve adaptable for use in a modulating system.

Another purpose is to provide such a valve having a readily removable stem.

Another purpose is to provide for complete shut-off when the valve stem is removed.

Another purpose is to provide an improved valve mounting.

Another purpose is to provide a modulating system relay.

Other purposes will appear from time to time in the course of the specification and claims.

I illustrate the invention more or less diagrammatically in the accompanying drawings, wherein:

Figure 1 is a vertical transverse section of parts in elevation;

Figure 2 is a section on an enlarged scale of line 2-4 of Figure 1;

Figure 3 is a section on the line 3-3 of Figure2;

Figure 4 is a section on the line 4-4 of Figure 2;

Figure 5 is a section on the line 5-5 of Figure 2;

Figure 6 is a section on the line 6-6 of Figure 1;

Figure 7 is a section on the line 'l---! of Figure 1;

Figure 8 is a front elevation of the electric control assembly;

Figure 9 is a wiring diagram; and

Figure 1G is a view similar to Figure 2, of a variant form of valve housing and assembly.

Like parts are indicated by like symbols throughout the specification and drawings.

Referring to the drawings, A, in Figures 1 and 6, generally indicates .a burner to which my system may be applied. It will be understood that the details of the burner do not, of themselves, form part of thepresent invention, and that my invention may be employed with other burners. However, as a matter of typical illustration, I illustrate my invention as applied for use with the below described burner.

Referring to Figure 6, I indicates an end ring and 2 an opposite end ring or plate. The plates are spaced apart and connected by a generally cylindrical housing 3, shown as of sheet metal. Positioned in the housing 3 and spaced inwardly therefrom, is a burner pot d having a generally cylindrical circumferential side Wall 5 and a concavo-convex end wall 6. The parts may be held together by bolts 1 extending between the rings I and 2. A flame ring 8 may be employedas an abutment and securing ring for the end ring I. The side wall '5 of the pot is shown as having a plurality of primary air inlets a spaced circumferentially thereabout and located at various distances from the open end of the pot.

is indicates a row of secondary air inlets which may be tilted toward the open end of the pot.

l l is any suitable re-circulating ring which may be connected with the flame ring 8 as by arms l2.

[3 generally indicates a fuel receiving cup having opposite lugs 4 and l5.

I5 is a screw threaded connector for the lug l 5.

I7 is a screw threaded connector for the lug l4. 11, also, defines part of the liquid fuel duct or inlet [8, which extends to the interior of the cup I3.

I9 is any suitable clean-out rod with its exterior handle 2t. Air may pass to the space' within the housing wall 3 and the pot 4 through the air inlet 2-11 of the end plate or ring 2. A booster motor 25 is shown as mounted opposite to aperture 2-41. It drives a fan 25 aligned axially with the aperture 2-11 and preferably positioned in the space between the endring 2 and the end wall 6 of the pot 4.

2-! is any suitable rheostat controllable by the manually operable knob 2 1-11.

The present invention is directed primarily to controlling and modulating the supply of liquid fuel to the cup 13 of the earlier described pot or vaporizing burner. It will be understood to be desirable to maintain as near an even temperature as possible, at the temperature level desired by the user. In burners of the type herein shown a supply of primary air, such as flows in through the inlets 9, mixes with a vaporized hydrocarbon to form a primary or rich mixture which is too rich for satisfactory combustion. This primary mixture moves toward the pot or housing outlet and receives a secondary air supply, such as is admitted through the secondary air inlets Ill. The secondary air supply is sufficient for complete combustion. The heating output of the unit is controlled by controlling the rate or volume of flow of liquid fuel to the evaporating cup l3. At the same time the supply of air is controlled by controlling the action of the fan 25.

In connection with the details of liquid fuel metering and supply, I illustrate in Figure 2 my preferred valve assembly.

35! generally indicates a valve housing structure, shown in considerable detail in Figures 2 and 3, which has an end enlargement 3| which surrounds the previously described liquid conduit or connector. The conduit or connector I1 is shown as having an intermediate reduced portion Ila which extends through the bore 32 of the valve housing lateral extension 3|. It will be noted, as in Figure 2, that there is a clearance between the inner surface of the bore 32 and the outer surface of the reduced connector portion Ila. The connector portion is provided with liquid fuel inlets l'lb. Liquid fuel is delivered along the duct 33 to the space about the reduced connector portion Ila and flows through the inlets [1b and is thus admitted to the liquid fuel inlet or duct I8, along which it flows to the interior of the cup [3. The liquid fuel supply which is metered by the below described structure comes initially, from any suitable supply or storage member not shown, through a feed pipe 35 to a float valve assembly generally indicated as B. The float valve assembly may include a strainer chamber 36 with its strainer 31 and a float chamber 38 with its main float 39 controlling any suitable needle valve 40 through a structure the details of which do not form part of the present invention. It will be understood that the float 39, in response to the level of liquid fuel in the float chamber B controls the further inflow of fuel by its control of the needle valve 40. Liquid fuel from the interior of the float chamber B escapes through the outlet duct or fitting 4|. This fitting is screw threaded as at 42 to be secured to the float chamber, and has an intermediate enlargement or hex 43 which serves as a spacer between the float valve assembly and the valve housing 30, and has its opposite end threaded as at 44.

45 is a locking nut or cap, threaded to the portion 44, and effective to draw the valve housing 30 firmly against the hex 43, thus maintaining the valve housing 30 and the float chamber B firmly secured to each other. Float chamber itself is supported on any suitable bracket 46 which may be secured to, or form part of the end ring 2 of the burner. There is a relatively short gap between the valve housing 30 and the burner. The interior of the valve housing is connected to the space between the burner side wall 3 and the burner pot for example, by the duct 41 extending to any suitable fitting 48 on the top of the float assembly, its opposite end extending into the space within the side wall.

Referring to the line of flow of liquid fuel through the valve assembly within the housing 30, the bore 5!) of the fitting 4| delivers liquid fuel to a space 51 surrounding an intermediate part of the fitting M. This space 5!, within the valve housing 30, receives liquid fuel through the outlets 52 of the fitting 4|. Two generally vertical valve bores are shown formed within the housing 30 as at 53, 54. Positioned in each such bore are the annuli 55, 56. Each such annulus is upwardly urged by a coil spring 51, the lower end of which abuts against a screw threaded closure plug 58. Each annulus 55, 56 has an upper seat 59 which seats against a hollow valve stem 60, 6|. Each such valve stem has a metering aperture 62, 63, and a vent hole 64, 65. Each valve stem is controlled by an adjusting or control knob I0 rotatable within an upwardly extending boss H of the valve housing 30. Within each such boss is a camming element 12 in the form of a set screw having an inner end 1211 which extends within the cylindrical bore within which each knob I0 rotates. The outer surface 4 of each knob is provided with a cam slot or track 13, whereby, in response to rotation of each knob 10 it is raised and lowered in the bore in which it rotates.

15 is an internal adjusting screw in the screwthreaded interior of the bore. It receives an engaging head I! integral with the upward extension 16 of the valve stem 60 or 6|. It will thus be understood that an initial or factory adjustment can be made by rotation of the set screw 15. When the device is assembled the springs 51 are effective to urge the annuli 55 or 55 against the lower end of the valve stems 60 or 6 l. The permitted upward limit of each valve stem is determined by the engagement of the head 1'! with the set screw 15. The operator may thus readily control or change the setting of each valve stem by merely rotating its appropriate knob 10. Such rotation raises or lowers the valve stem 60 or BI, and thus raises or lowers the metering aperture 62 or 63. It will be understood that when the control knob is upwardly removed, the springs 51 are effective to move the annuli 55 or 56 upward sufficiently to prevent any inflow of liquid fuel from the float chamber. It will be noted that fuel flows to the valve stem 61 along the duct and fuel flows to the valve stem '60 along the duct 8|. These ducts are at such a height as to have their delivery ends masked by the annuli 55 or 56 when the appropriate knob 15 is removed. The knob 10 can be removed by aligning slot 10a with the set screw 12. As will be clear from Figure 2 whatever fuel passes the metering aperture 62 reaches the cross passage 85. This cross passage extends to the space beneath the metering valve 6|. Thus the total of fuel passing through the two metering apertures 62 and 63 flows through the extension 86 of the passage and thus reaches the outlet duct 33.

90 is an adjustable needle valve which may be adjusted toward and away from any suitable seat 9|. It may be screw threaded as at 92 for adjusting in a threaded bore, the upper end of which is closed by any suitable threaded closure 93. Thus the needle valve may be set at the factory or by a serviceman, to pass a suitable maximum fuel flow. It cannot readily be tampered with on the job.

In considering the operation of the two valve stems it will be clear, as shown in Figure 2, that each valve stem, with its metering apertures 62 or 63 is surrounded by a body of liquid fuel delivered from the float chamber. Fluctuation in the level of liquid fuel in the space surrounding the valve stems 60 or 6| varies the head of liquid about the metering aperture and thus varies the rate of flow of liquid through the metering apertures. In the use of the device in a burner which may be described as burning, for illustration, at the three levels of pilot fire, intermediate flre, and high fire, the valve stem 68 may be described as the high fire valve stem and the valve stem 6| as the pilot valve stem. The operation of the valves in response to an increase in the level of liquid fuel surrounding the valve stems will later be described.

Referring to the Wiring diagram of Figure 9 it will be understood that the motor 25 is preferably constantly rotating whereby the fan 26 is constantly maintaining a head of air pressure in the space surrounding the pot 4. Thus an adequate supply of primary and secondary air is delivered through the apertures 9 and ID. The

rate of the motor may be controlled or adjusted for example, by the rheostat 2].

I illustrates a manual switch which may be located in the control box as shown in Figure 8. When the switch I00 is closed power is delivered through a circuit including any suitable power line or source of electrical power not herein shown.

IDI indicates an anticipating room thermostat with its fixed contact I02, its warping bar I03, and its anticipating coil "33a.

I04 is any suitable means, such as a heat motor, for performing work in response to the closure of the circuit through the room thermostat. Its actuating member I05 may rotate the pivoted contact I06 in relation to the rheostat coil I01. As the length of the coil It! in the circuit is reduced by the movement of the contact lever I 06, the speed of rotation of motor 25 is increased. Similarly, as the arm Hi5 drops toward the position in which it is shown in Figure 9 the motor speed is reduced. If the arm I86 moves a sulficient distance to engage the moving contact I08, the contact I08 is thereby moved to circuit break ing position. This prevents the heat motor from being damaged by overheating. As soon as the contact at I68 is broken, the lever arm I86 will start to descend, but will shortly resume its ascent. It will be understood that any suitable transformer I I!) may be employed for the heat motor.

In the operation of the device, it will be understood that the rate of delivery of air to the space about the pot 4, and thus through the apertures 9 and I0, is controlled primarily by the rate of rotation of the fan 26. But as the pressure within the wall 3 increases, air pressure within the float chamber B is affected through the air connection 41, 48 between the burner space and the interior of the float chamber. The increase of pressure in the valve housing B raises the level of liquid fuel in the spaces about the valve stems 60 and GI, and thus increases the head of liquid fuel above the metering apertures 52 and 63.

- With reference, for example, to Figure 2 the oil level in the float chamber, which is controlled by the float 39 is indicated at X. The pilot pressure level of the liquid fuel is indicated at Y and the high fire pressure is indicated at Z. The level of the fuel at intermediate pressure will be understood to be intermediate Y and Z.

With reference to the form of Figure 10, it will be understood that while, under many circumstances, I find it advantageous to have the twin structure of Figure 2, nonetheless, .it is practical to employ a structure having a single valve stem or member 6m in which the pilot aperture 63a is substantially below the fuel level, whereas the high fire aperture 62a. is located adjacent the fuel level or, specifically, adjacent the pilot pressure level. Thus the pilot orifice is at all times substantially below the level of the fuel, whereas the high fire orifice may be above the level of the fuel. Otherwise, the structure has been shown as identical with that of Figure 2, save for the omission of the separate high fire valve stem 60 and its associated parts.

It will be realized that whereas I havedescribed and claimed a practical and operative device, nevertheless, many changes may be made in size, shape, number and disposition of parts. I therefore wish my description and drawings to be taken as in a broad sense illustrative and diagrammatic, rather than as limiting me specifically to the details of my disclosure. It will be under stood, for example, that my control system may be employed with other burners and that my val-vestructures may be applied to other uses than controlling burner fuel.

The use and operation of the invention .are as follows:

I provide an efficient modulatingsystemwhereby the operator may enjoy a fairly even temperature in the space heated by a burner controlled in accordance with the above described system. Any suitable tank or supply means may be employed for supplying liquid fuel along the pipe 35 to the float chamber assembly B. The inflow of fuel past the Valve 40 is controlled by the float 39. The fan 2E constantly maintains above atmospheric pressure in the space around the burner pot 4. The pressure developed by the fan is transferred to the sealed top float chamber 38 by the pressure line or duct 41, 48. Thus it maintains a head of fuel in the metering valve in irect proportion to the pressure developed in the burner housing or casing 3. The speed of the fan is governed by the modulating relay unit illustrated in Figures 8 and 9. When the control arm I slides from its full line position of Figure 9 through its dotted line position it increases the fan speed from its initial slow pilot speed, at an ever increasing rate, until thecapacity high fire speed is obtained when the arm I06 has reached its upper dotted line position. Travel of the arm is accomplished by the heat motor 104 which receives its impulses from the room thermostat. The fuel fiows from the float chamber through the above described duct to the space about the pilot valve stem BI and also to the space about the high fire valve stem 59. It will be'noted that in Figure 2 the pilot metering orifice 63 is substantially below the upper level of the head of liquid fuel to which it is subjected and that, therefore, there i substantially no fluctuation in the rate of flow of liquid fuel through the pilot orifice. tthe pilot stage the fuel surrounds the high fire valve stem 66 to a pressure level which is below the metering orifice E2. Ca-pillarity draws the fuelabove the orifices, the orifices being submerged at all times, even durmgperiods of nofiow.

Referring to the space surrounding the valve stems B0 and G I, that portion above the indicated fuel, within and without the valve stems, represents air at atmospheric pressure. When the easing pressure of the burner is transmitted to the top of the air-tight float chamber, the'fuel levels in both the pilot and the high fire chambers are forced upwardly in response to pressure increase.

' This increases the rate of flow through both the pilot and high fire pressure in proportion to the increase in burner .casing pressure. But the in creased rate of flow through the pilot orifice is small compared to the increase in flow through the high fire orifice. The fuel passing through both orifices has a free drop which may, for example, be approximately at one-half inch at intermediate fire flow, indicated by the solid drops emerging from the valve stem orifices. The fuel as shown in Figure 2 levels off at approximately the center of the oil outlet 18 to the burner. It will be clear from Figure 2 that both fuel supplies merge and then pass through the metering oriflees or seat 9i. As pressure is increased onthe body of oilin the float chamber the level of oil in both pilot and high fire chambers rises.

.A vitally important feature of my modulating fuel control system is the modulating relay of Figures Band 9. Since it operates by a heat motor it is affected by the temperature of the space in which it is mounted. The relays should be mounted in the same space as is controlled by the thermostat.

Whereas I have shown my modulating system with two stems, it will be understood that I may employ a single stem, as shown in Figure 10.

It will be noted that the interior of the valve assembly is readily accessibl for inspection and cleaning. The valve stems may readily be removed. When they are removed the springs 51 automatically raise the annuli to out off the further inflow of liquid fuel. It will be further understood that each stem may be individually removed without affecting the fiow of fuel to and past the opposite stem. As above mentioned, when the control or modulating arm I06 reaches high fire maximum its movement is effective to move the control element I08 to avoid overheating in case of high ambient temperature.

In considering the use of the device some differences between my solution and ordinary room controls should be kept in mind. In the ordinary room control, when the room thermostat makes contact through a snap-acting relay, it throws the burner into operation. The burner stays in operation all during the time that the thermostat is in contact. This may be anywhere from fifteen minute to an hour or more. The anticipating coil usually acts for about a half degree, so that as soon as the ambient temperature around the thermostat is within a half degree of, say, 70 degrees, the burner is shut off and the residual heat in the system brings the thermostat up to '70 degrees.

In my system, I use a larger or hotter anticipating coil 13a, so that the temperature of the bimetal leaf of the thermostat is brought up to the predetermined shut-off point very rapidly, usually within less than a minute. During this time, heat is being stored in the heat motor, and the arm I06 starts to rise. With the gradual increase of fan pressure, the heat from the burner transmitted to the room in which the thermostat is placed gradually decreases the length of time that the thermostat contacts are closed. For example, say the room has dropped to 69 degrees, and at that temperature the thermostat is in contact fifty percent of the time and out of contact fifty percent of the time in any given time interval, such as one or two minutes. As the ambient room temperature rises slightly, the length of time in which the thermostat is making contact will gradually decrease, thus supplying less heat to the heat motor, and the arm I06 will find a position which will exactly satisfy the set conditions of the thermostat.

In practice, the employment of the restriction valve 90 is important. It is a matter of expediency whether the restriction or needle valve 90 is on the burner side of the valve assembly or not. It could equally well be at the other side of the metering orifice. It performs the function of restricting the maximum flow of fuel in accordance with the law that the rate of flow is proportional to the square root of the head. As long as the flow through the metering orifice is less than the possible flow through the restrictive orifice, the restrictive orifice, controlled by the valve 90, does not come into play. The rate of flow increase through the high fire orifice or metering aperture 62 or 62a is very rapid, inasmuch as a few hundredths of an inch increase in pressure may double, or even triple, the head at that point. But as soon as the restrictive valve comes into action. a few hundredths of an inch is a very small proportion of its control head, and, therefore, its rate of increase is much smaller. In going from pilot to intermediate fire a rapidly increasing rate is important, as it is advantageous to reach the intermediate fire stage as soon as possible. But as soon as the fire stage approaches maximum, a rapid rate of increase is disadvantageous, as if the same rate of fuel increase were continued, too much fuel would be delivered for the amount of available air supply.

In effect, I therefore combine two different metering methods, or two different responses to an increase in the head of fuel. During the period when a rapid increase is desired, a rapid increase is available, in response to the controls employed. But when a further continuance of the rapid rate of increase would result in an excess fuel supply, the rate of increase is, at the proper point or zone, drastically reduced.

Whereas in my structure I find it advantageous to provide clearances in the space about the hollow valve stems, sufficiently small to cause rise of liquid by capillary attraction, it should be kept in mind that the ability to control a small amount of fuel through a relatively large orifice will still exist, even if there were no surface tension or capillary attraction. However, it is an advantage to have the high fire orifice 62 normally above the fuel level so that, when the speed of the fan motor varies, or the fan motor stops completely, the flow of fuel is correspondingly affected.

Broadly stated, my system includes a modulating burner with an air confining housing, a fan which delivers air under pressure to the housing and means, responsive to temperature changes in the heated space, for varying the rate of rotation of the fan and thus for varying pressure in the confined air housing of the burner. Changes in the burner air pressure are reflected in the sealed liquid fuel receiving chamber. An increase in air pressure in the burner, and thus in the sealed fuel chamber raises the fuel level to which the metering apertures are subjected. In other words, liquid fuel rises in the upright passages or wells in which the hollow valve stems or valve walls are positioned. Whereas, at the pilot stage a constant flow of liquid fuel passes through the pilot metering aperture, the high fire metering aperture need not pass liquid fuel at all. When the house thermostat calls for heat and speeds up the fan, there is then a slight rise of liquid fuel in both wells. This does not substantially increase the rate of fiow of liquid fuel through the pilot metering aperture, since it is already subjected to a head of liquid fuel. But the metering orifice of the high fire unit, operating as a weir passes a greatly increased flow of liquid fuel. This weir continues until there is a definite head of liquid fuel above the high fire metering aperture. In other words, at pilot fire a constant and very small delivery of liquid fuel is maintained. A relatively slight rise in the liquid level results in a very substantial fiow of liquid fuel through the high fire metering aperture.

The control means for varying the rate of fan operation are accurate, safe, and efficient. There is no possibility of overheating, because of the safety connection above described. A very slight rise in ambient temperature breaks the heat motor actuating circuit and permits the rheostat contact to move toward its low speed position. I thus provide a very precise and efiicient modulating system.

I claim:

1. In a metering assembly for controlling the flow of liquid, a source of liquid including a supply duct, a hollow well, at least one hollow stem in such well, such stem having an outer face spaced inwardly from an inner face of the well within which it is located, the interior of the well exterior to the stem being in communication with the supply duct, the stem havin a metering liquid discharge means with a capacity which is dependent upon the liquid level in the well, and a delivery duct in communication with the interior of the hollow stem adapted to receive and deliver the fuel discharged through the discharge means of the stem, said stem being 1ongitudinally adjustable within said Well and having a masking portion which, when positioned over the liquid communication between the interior of the well and the supply duct, will mask it and shut on liquid communication between the sup-ply duct and the well.

2. The structure of claim 1 characterized by and including spring means for biasing the stem and masking portion upwardly.

3. The structure of claim 2 characterized by and including manually operable adjustment means for adjustably positioning the stem longitudinally in the well, the spring means having a resiliency such that, when the stem is free for unlimited longitudinal movement in the well, the masking portion will be positioned over the liquid communication between the interior of the well and the supply duct.

4. The structure of claim 1 wherein the metering liquid discharge means includes a plurality of orifices in the stem of different metering capacity.

5. In a metering assembly for controlling the flow of liquid, a source of liquid, including a supply duct, a plurality of hollow wells, a hollow stem in each well, each stem having an outer face spaced inwardly from an inner face of the well within which it is located, the interior of each well exterior to its stem being in communication with the supply duct, each stem having a metering liquid discharge means with a capaclty which is dependent upon the liquid level in the well, the capacity of th metering liquid discharge means in each stem being difierent from the capacit of any other, and a delivery duct in communication with the interior of the hollow stems adapted to receive and deliver the fuel discharged through the discharge means of the stems, each stem being longitudinally adjustable within its well and havin a masking portion Which, when positioned over the liquid connection between the interior of its well and the supply duct, will mask it and shut ofi liquid communication.

6. The structure of claim 5 characterized by and includin spring means for biasing the stems and masking portions upwardly within their wells.

7. The structure of claim 6 characterized by and including manually operable adjustment means for adjustably positioning each stem longitudinally in its well, the spring means having a resiliency such that, when a stem is free for unlimited longitudinal movement in its well, its masking portion will be positioned over the liquid communication between the interior of the well and the supply duct.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,583,238 Scudder May 4, 1926 1,645,443 Meyers Oct. 11, 1927 1,743,966 Goudard Jan. 14, 1930 1,789,357 Metcalfe Nov. 4, 1930 1,833,273 Williams Nov. 24, 1931 1,854,749 Lord. Apr. 19, 1932 2,045,821 Austin June 30, 1936 2,367,038 Martin Jan. 9, 1945 2,416,514 Chadwick Feb. 25, 1947 2,507,119 Randall et a1 May 9, 1950 FOREIGN PATENTS Number Country Date 212,909 Great Britain Apr. 9, 1925

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