US2286173A - Apparatus for proportioning the flow of fluids - Google Patents

Description

J. J. MAXON June 9, 1942.

APPARATUS FOR PROPORTIONING THE FLOW OF FLUIDS Filed Nov. 14, 1939 2 Sheets-Sheet 1 .l. .l. m 9 oo 7- 6 5 A? Z] k N m m m v A w l A K v .7 T4 2 1 m N H mm 2 3 IN!!! 1 n7 3 0 F .l I 5 o 3 v. 2 2| v 6 J APPARATUS FOR PROPORTIONING THE FLOW OF FLUIDS Filed Nov. 14, 1959 2 Sheets-Sheet 2 FIG. 5

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d oHN J. MAX'QN Patented June 9, 1942 UNITED STATES PATENT OFFICE APPARATUS FOR PROPORTIONING THE FLOW F FLUIDS John J. Maxon, Muncie, Ind., assignor to Maxon Premix Burner Company, Muncie,-Ind., a cor- Duration of Indiana Application November 14, 1939, Serial No. 364,377 Claims. (Cl. 2773) This invention relates to improvements in appressure, This frictional resistance varies with paratus for proportioning the flow of fluids. each individual installation clue tothe fact that Experience in the proportioning of gas and furnaces are not exactly alike, and that inair, and in the proportioning of liquid fuel stallations of piping are not exactly alike either (either oil or liquefied gases) and air, for the 5 as to diameter or length, or as to the number,

purpose of making a combustible fuel-air mixcharacter and arrangement of elbows and other ture for use in industrial furnaces, ovens, and fittings. The effect of this frictional resistance, the like; has brought to attention certain factors like that of he internal furnace pressure above of how to obtain control of such fuel-air mixof the fuel inlet and of the air inlet in the pro ture so that a-uniformly eflicient or a uniformly portioning means. I

controlled furnace atmosphere, or both, may be For the reason that the effectiveness of "the had. air inlet is less when the furnace is operating One of these factors is internal furnace presat maximum firing rate, than when the burners sure. It is well known that if a relatively large are turned down low; and that therefore there amount of fuel is being burned in a furnace dur-- is more area at the air inlet at high firing rates ing a predetermined length of time, the vents than is needed proportionately; and for the for the spent gases become choked, thus tending further reason that there is no way to predeterto set up within the furnace a considerable posimine the proportional air inlet area until the tive pressure. And, on .the other hand, if in an equipment is installed on a furnace and started the same furnace and during the same length of up under actual operating conditions, it becomes time, a relatively small amount of fuel is being necessary to change the gas-air fuel ratio,i in burned, the functioning of the vents is normal, conformity with the internal furnace pressure,

-' ingly remain slight. Similarly, in a furnace to countered. In o her wo d the appar tus for,

so functioning as to carry off spent products of compared with the lowerresistance which pre-' combustion during the lowflring rates, without vails at reduced flring rates. choking, These resistance pressures act to retard the These facts teach that in furnaces generally, flow of the fluids through both the fuel inlet and there is a tendency toward a building up of inthe air inlet, such action being of greater intencreased internal pressure when the burners sity upon the air flow than upon the flow of the therefor are operating at wide open position; liquid or gaseous fuel. Hence it is found genand a tendency to a lowering of internal furerally that in an industrial burner system when nace pressure when the burners are operated operating at high firing rates; the effect of the at intermediate or lower firing rates. This 40 internal furnace pressure is to cause propor-' changing internal pressure has a direct bearing tionally less air to enter the furnace through the upon the performance of all industrial burner burners than is able to enter against the lower systems regardless of the means employed for internal furnace pressure prevailing at reduced measuring out the quantities of fuel and the firing rates. Thus there is an inherent tendquantities of air for the mixture thereof. ency in all known industrial burner systems to Another of the factors above referred to, is produce a too rich" fire at high firing rates, frictional resistance. By frictional resistance, is (that is to say, a type of firein which there is meant, resistance that is present in the pipes or insufiicient volume of air to complete combustion pipe lines which conduct the gas and air to the of fuel) thereby leading to, ineflicient operation. burner nozzles through which the fuel mixture The condition just mentioned may be overis burned. This resistance increases as the firing come by changing an adjustment on valves of rate goes up, and it decreases as the firing rate proportioning devices hitherto devised and well is diminished. In these instances the influence known, so that the area of the air inlet is inon the burner system is much the same as the creased to admit slightly more air and thus to influence which is incident to internal furnace restore the mixture proportions suitable for producing the desired furnace atmosphere or combustion efficiency. It is well known however, that when such an adjustment is resorted to-so as to bring the proportions of the fuel mixture elements into desired balance at a high firing rate-the fire becomes lean" or oxidizing as soon as the firing rate is reduced. This effect is incident to the admittance of a too-high volume of air against the lowered internal furnace pressures or the lowered resistance conditions that prevail when burners are: operated at reduced firing rate.

It is also well known that adjusting devices are also provided in proportioning apparatus as hitherto devised, whereby alteration of the area of the fuel inlet may be had. However, in. all

prior apparatus of the kind referred to, the predetermined and fixed fuel-air ratio is unchanged. Whereas, by the use of. such prior devices, compensation may be had for variables met with in furnace operation, such as change in the B. t. u. value of fuel; change in the overall character of furnace atmosphere (such change being sometimes necessitated by a change in the type of work being handled through the furnace or oven) and change in the basic or main pressure at which fuel or air is supplied to the proportioning device; (as in instances wherein a furnace with burners operating on compressed air is modified so as to be handled with burners operating on air supplied by a low pressure fan) it is believed that no proportioning apparatus has hitherto been developed to compensate for the variables. with which the present invention has to do, and which said variables are again referred to briefly, as follows;

Changes in internal furnace pressure caused by increase or decrease in firing rate of the burners.

Changes in frictional resistance of the air or fuel manifold piping (caused by increase or decrease of the rate of flow of fluids through these headers).

Changes in pressure at which combustion air is supplied up to the proportioning apparatus (that is, if furnace is equipped with blower or fan, and in which instance the pressure of the air supply will tend to weaken slightly as the firing rate increases), and

Changes in pressure of fuel supply up to the proportioning apparatus (caused by tendency of gas pressure or oil pressure to drop slightly as the firing rate is increased).

To provide compensation for all variables met with in burner systems for furnace or oven operations, inclusive of the variables lastly above mentioned, suchcompensation being regardless of the type of mixer through which the proportioned fluids are to. be confined and used, my idea is to afford means whereby to adjust the proportions of the two fluids (that is-to adjust the fuel-air ratio) at and to maintain said adjustment for any point in the capacity range of the burner system.

Accordingly, the object of my invention, broadly stated, is to provide an apparatus afford: ing facility whereby to vary the volume of inlet of air as received from a supply source at any pressure, and to vary the volume of the inlet of fuel as received from a supply source at any pressure, and to modify the proportioning so obtained, at and to establish such modification for different stages of the feed flow of the proportioned air and fuel; by such facility, the combustible mixture ultimately resultant from said proportioning, being of consistency which is dictated by the conditions under which the burner system and furnace or oven are operated.

The above stated general object, as well as other and more specific aims of my invention which will presently be apparent, are accomplished by, and my invention is embodied in the new construction, combination and arrangement of parts described in the following specification, and illustrated in the accompanying drawings. The different parts of the invention are identified by suitable characters of reference applied to them in the several views in the drawings, in which- Figure 1 is a front view .of my new fluid-flowproportioning apparatus, a portion of cover plate being broken away.

Figure 2 is a side view, taken in the direction of arrow 2 in Figure 1, a portion of the air-inlet flange fitting being broken away.

Figure 3 is a side view of Figure 1, in the direction of arrow 3 in Figure 1, a portion of the cover plate, and a portion of the arm structure which is coordinated with the air inlet gate arm, and a portion of the flow discharge fitting being broken away.

Figure 4 is a vertical cross section view taken on the broken line 4-4, and in the direction of arrow 4 in Figure 1.

Figure 5 is a top plan view of Figure 1, taken in the direction of arrow 5 in Figure 1; cover plate 10 being removed.

Figure 6 is a top plan view of the gate arm detached, a portion thereof being broken away and disclosing to view the resilient cam strip, and a portion of the latter being broken away, disclosing to view the curved slot underneath same.

Figure 7 is a sectional top plan view taken on the broken line 1-1, and in the direction of arrow 1 in Figure 1.

Figure 8 is a diagrammatic view showing the gate valve at half-on position.

Figure 9 is a diagrammatic view showing the gate valve at on position.

Figure 10 is a detachedvertical sectional view on the broken line ii -"i0, in the direction of arrow I0 in Figure 5.

The meaning of the word gas as herein occurring, is inclusive of liquid fuel. This fuel may be liquefied gas of any one of the many kinds known and widely used, and/or oil.

By the term "combustible mixture as used herein, is meant the combined volumes of gas and of the air used for the combustion thereof after such volumes will have passed from the discharge openings of my new and improved apparatus described herein. 3

Cast metal casing structure I! embodies a vertical bore I3 at the top of which is secured a plate 14 provided with a circular opening I. Openings which communicate with said bore II from opposite sides thereof, are designated as air inlet [8, and air outlet iii. A conventional flange fitting 20 accommodates air inlet pipe 2|. A hollow cylindrical gate 22 and which is rotatively retained in the said bore l3 embodies a circular boss which is received in the bore I! of the said top plate It. The said gate is provided with apertures 23 and 24 so positioned, that with a turn of the gate through one fourth of a revolution its status is changed from closed position to open position, and vice versa. Axial shaft 21 which is made fast, to said gate as by being threaded therein and secured by a'nut 28; and

by a stud pin which projects from the top of said gate, constitutes a power transmitting connection and it will presently receive further reference.

Embodied by said casing, and located closely adjacent to the said bore I3 is a cavity 3|. At an open side thereof a plate 32 is secured, as by cap screws 33. An opening from said cavity and which is located adjacent to said air outlet I9, I designate as gas outlet 34. Side face 35 of the casing is adapted to have secured thereto,

a hollow fitting 36 to span said air outlet l9 and the said gas outlet 34, and to which may be attached a delivery or conducting conduit (not shown) of any desired type. Threaded opening 31 in the side plate 32 and which is adapted to receive gas inlet pipe 39 communicates with the interior of an entry box 38 which is integrated with said side plate, as illustrated in Figure 4.

A fluted flanged valve head 40 which is retained loosely in a bore in the top side of the said entry box, and which is seated as at 4|, has a stem 42 which is received in the central bore of an abutment head 43. v

This abutment head is screwed to sealed position in the bottom side of said entry box. A helical spring 45 whose one end bears against the shank of said abutment head has its other end impinged against the said valve head 40, the latter thereby being retained yieldingly in its closed position as indicated in Figure 4.

Loose in the bore of a bushing 46, and which said bushing in turn is slidingly retained in a bore 44 therefor provided in the casing at position immediately above the valve head 40, is a push rod 41. This push rod, made preferably of non-corrosive metal, is of such length that with its lower end in engagement with the said valve head 40, its other end extends a predetermined distance above said bushing. Packing in said bore 44 constitutes a closure at said push rod and to prevent egress of gas from cavity 3|. A helical spring 5| which is disposed within a counterbore of the said bushing 46, and upon a washer 52 that reposes on said packing, urges the said bushing upwardly, and for the purpose presently to be set forth.

A member which consists of a segmental plate 53 having a hub 54 provided with a bore 55, I designate as an arm structure. For moving of this arm structure. a projecting member 68 available as a handle connection to which mechanical means (not shown) may be attached, is provided. In the bottom face of said hub is a recess 56. A slot 51 of curvature struck from the axis of said hub is so located, that upon lowering the said arm structure to its operative position (see Figure 4) the shaft 21 will have been received in the bore 55, and the stud pin 30 will have been received in the recess 56 of the said hub, the push rod 41 will have been received in the slot 51, and the bottom face of the said arm structure at slotted portion thereof, will have come into engagement with the top face of the aforesaid bushing 46.

Upon screwing the nut 58 on the upper portion of said shaft 21 .to tightened engagement with the said hub, the said arm structure will have been securely united with the said gate 22, the said shaft 21, stud pin 30 and nut 58 constituting power transmitting devices interconnecting the arm structure and the gate, whereby upon a movement of the arm structure, there is a corresponding movement of the gate.

At the top surface of the casing is an index point Z and which is located in registration with a line bisecting the center of said push rod 41.

In the marginal top portion 65 of said arm structure, and which said top portion is of curvature the same as slot 51, threaded adjusting pins 61 are arranged in succesive order, as shown in Figures 1 and 5. They are designated by numerals-reading from left to rightnamely, 0, I, 2, 3, 4, 5, 6, 1, 8, 9, I0 and II. Each of these pins is individually adjustable by the use of a suitable implement such as a screw driver, and each is capable of being stayed at the position to which it is adjusted, as by a lock screw 69.

It is by the adjusting vertically, of these pins, carried as they are, in relation to the push rod; and each, constituting, as it does, a power transmitting element to actuate the push rod when brought into coacting relation with the latter; that a determinate measure 'of the range of downward movement of the push rod (and therefore a determinate measure of the extent of opening movement of the gas valve) may be had for and in relation to any one of the multiple settings to which the air gate may be moved, such measure being independent of the measure had at any one, and all other of said multiple settings.

To facilitate the passing of the pins into the zone of engaging registration with said push rod, and to contribute to ease in handling the arm structure in its moving of the air gate I provide the parts as follows; A body piece 63 for manual use, or as a secured at its base portion as by cap screws 66 to the part 53 of the said arm structure, embodies marginal portion which is of curvature the same as the curvature of said slot 51. Said body piece is of formation in cross section, as shown in Figure 10, to provide a curved cavity 64. A curved strip 6| made of flexible material such as laminated steel and of suitably light gauge, has medial arm portion secured, as by cap screws, to the underside of the base portion of the part 63. This strip is poised within said cavity 64 and immediately underneath the se ries of pins, and it is of length to span the reach of the curved slot 51.

medial arm portion, the urge of the strip is upwardly, and therefore toward the bottoms of said pins, said bottoms being rounded as indicated in the drawings. Against the underside of the strip 6|, the push rod 41 (urged upwardly and toward said pins by the spring 45) impinges. Said strip, yielding as it does, in the portion thereof immediately at the push rod and adjacent pin, it constitutes a practicable bridging to facilitate the passing of the pin to engagement with the said push rod. Pressure of spring 5| against bushing 46, holds the latter against the underside of part 53, thereby staying the arm structure.

In readiness to be operated, the invention with its several parts in their correlated positions, appears as shown in the drawings, the arm structure having been moved in the direction of the arrow off, to the extreme end of its stroke, the indicator numeral 0 having been brought to the zero point Z. The air inlet It? now is closed. The gas valve head 40 is in the closed position.

The arm structure, by the handle 68 is now moved in the direction of arrow on, see Figure 5) bringing the indicator numeral 1 to index Z. Pin at I is then adjusted to afford the desired measure of opening at gas valve 40. When tests at the furnace (not shown) indicate that By the action of said the proper amount of gas volume has been obtained with relation to the volume of air which is being admitted at the gate at air inlet I 8, the adjusting pin l is stayed by tightening the lock screw 69. Now the handle 68 is again moved in the direction of arrow on bringing the indicator numeral 2 to the index Z. Pin 2 is then adjusted so as to afford the desired measure of opening of the gas inlet valve 40. When the tests continued at the furnace indicate that the proper ratio of gas to the air, as the latter is admitted at I8, is had (at the stage wherein the pin 2 is at index Z) its lock screw is tightened. The handle 68 is again moved in the direction of arrow on, the pin 3 being brought to index Z and then adjusted to and made fast in desired position. With each succeeding shift of the said arm structure, there is the adjusting and staying of the pins at 4, 5, 6, I, 8, 9, l and H in their successive order.

It will be understood that by the urge of spring 48 against the valve head 40, the push rod 41 is held constantly pressed upwardly against the face of the flexible strip GI, and that the latter affords a suitable bridging tosmoothly ease the passing'by the pins, one after another, to their respectivepositions as related to the top of the said push rod.

A cover plate in fitted connection with the arm structure as by a cap nut ll applied to the end of gate shaft 21, constitutes a protective shield for the said arm structure and the adjusting pins 61.

An annular ring shaped plate 12 of predetermined internal diameter and which is made fast to the side of the casing, as by cap screws 13, determines the diameter of, and it centers the discharge flow of the proportioned streams of air and gas.

The invention lends itself to use in connection with automatic control facilities of any conventional type. In such instance, a crank member (not shown) is substituted for the handle 68.

The invention renders practicable the supplying of air and gas volumes in proportions suitable for combustible mixtures intended for bumer systems generally, and whether the point of delivery of the proportioned volumes is adjacent to, or is remote from, the locus of the apparatus. It lends itself tonin'stallations whereby the gasair proportions which it supplies, may be discharged under pressure into the piping system and may be burned from one nozzle or from a plurality of nozzles. Either the open port, or the sealed port method of firing may be practiced. Line type nozzles also may be used.

The utility of my invention and the advantages accomplished by its practice are obvious. When tests of the combustible mixture (said mixture being constituted at the furnace (not shown) by suitable intermingling of the gas and air streams flowing from the gas outlet 34 and the air inlet l9 respectively) will have indicated the nature of change in the proportions of said streams necessary to compensate for such specific. atmosphere conditions in the furnace as may have been encountered, variation of the volume of gas flow may be had and maintained at any stage in the capacity range of firing. Or, in other words,

- at any setting of the air inlet gate between its extreme positions of oif" and on. When the apparatus will have been set in conformity with the furnace conditions for which it is adjusted, the firing rate is apparent by observing the position at which the said arm structure is set.

Included in the class of plant organizations wherein the problems of obtaining efllcient burner system operation and efficient combustion are common, are annealing furnaces, forge furnaces, furnaces for heat treating, steel mill furnaces, and reverberatory melting furnaces. In all of these, my invention is of utility in making possible the obtaining of proportioning of the elements going into the make-up of the required combustible mixtures whereby compensation is had as dictated by local conditions.

In the embodiment of my invention as herein illustrated and described, the amount of machine work involved is relatively small; the different parts are capable of being economically assembled and interconnected, and the apparatus in its entirety is close built and substantial, and is not liable to get out of order. Access may be readily had to the interior thereof when necessary for inspection and cleaning or for renewals; and the device throughout is capable of bein modified as to details to meet capacities of all ranges, and'various installations conditions.

Whereas I have shown and described my invention in form embodying structure and details of preferred, formation and arrangement, it will be understood that modifications may be made in the details of construction, form, and arrangement of the several parts, within the scope of the invention as it is defined in the appended claims, without departing from the spirit or principle of the invention or sacrificing any of its advantages.

What I claim as my invention is:

1. Apparatus for proportioning the flow of air and fuel to industrial burner systems, comprisarate and independent compartment, said entry box having fuel inlet and outlet connections and a stemmed valve, a compression spring constantly urging said stemmed valve towards closed position, a push rod extending through a packing gland in the wall of said entry box and aligned for direct engagement with said stemmed valve and operable to open same in opposition to the urge of said compression spring, means for. actuating the push rod simultaneously with the moving of said arm structure and for varying at different positions of the gate the ratio between the extents of opening of said gate and stemmed valve, said means including a series of individually adjustable threaded pins carried by the said arm structure and so located that upon movement of the latter through its range of positions, the threaded pins will be brought successively into engagement with the push rod, each in its turn thus actuating the latter, a fiexible strip carried by said arm structure and interposed betwen the push rod and the threaded pins, to facilitate their said engagement, whereby at each of the multiple positions to which said arm structure is moved, the flow of fuel and flow of air are proportioned one to the other, and an air-fuel ratios prevailing at other positions, is established and maintained.

2. Apparatus of the kind described, comprising a valve for the air, and a valve for the fuel, an arm structure operable to move the air valve, a spring to urge the fuel valve toward closed position, a push rod carried by the fuel valve and operable to resist said urge, successively arranged pins carried by said arm structure in line with said push rod, each being individually adjustable with relation to said push rod, means to secure each of said pins in the position to which the latter is adjusted, and a flexible bridging strip fixedly secured to said arm structure and carried thereby in position between said successively arranged pins and the said push rod.

3. Apparatus of the kind described for proportioning the flow of air, and the flow of fuel, to industrial burner systems and the like, comprising a casing structure having a cylindrical bore and being provided with an open compartment adjacent to said bore, and each of opposite sides of said bore having an opening therein, one for ingress of the air to, and the other for the egress of the air from the said casing structure, and there being an outlet from said compartment, a gate iournaled in said bore and having ports so arranged that with a turn of the gate through ninety degrees in one direction the ports are transposed from closed position to open position, and when said gate is moved through ninety degrees in ,the opposite direction the said ports are transposed from open position to closed position, a segmental arm structure coordinated with and operable to move the gate from one to the other of its extreme positions, an entry box associated with and constituting a closure of said compartment and which said entry box is provided with a fuel inlet, a valve for the fuel inlet, a push rod engaged with said fuel valve and extended through the wall of thecasing structure, spaced threaded pins carried by and protruding from the circumferential marginal portion of the said arm structure and which are capable of being screwed to and fastened at adjusted positions, packing at the said push rod, a brake device to yieldingly stay the said arm structure at any of the positions to which it is moved, and an arcuate flexiblev strip fixedly secured to and carried by the said arm structure at a plane between the push rod and the said pins.

4. Apparatus of the kind described for proportioning the flow of air and the flow of fuel to industrial burner systems and the like, comprising a casing structure having a cylindrical bore and there being an open compartment within said casing, and each of opposite sides of said bore having an opening therein, one for ingress of air to, and one for egress of air from the said casing structure, and there being an outlet from said compartment, a gate Journaled in said bore and having ports so arranged that with a turn of the gate through ninety degrees in one direction the ports are transposed from closed position to open position, and when the gate is moved through ninety degrees in the opposite direction the said ports are transposed from open position to closed position, an entry box associated with and constituting a closure of said compartment and which said entry box is provided with a fuel inlet, a valve for the fuel inlet, a push rod engaged with said fuel valve and extended through the wall of the casing structure, a rotatably mounted arm structure, power transmitting devices interconnecting the arm structure and said gate, means to constantly urge said fuel valve toward closed position, a brake device to yieldingly stay the said arm structure at any of the positions to which it may be moved, a flexible strip fixedly secured to and carried by said arm structure in registration with said push rod. and a series of individually adiustable pins carried by said arm structure, and against the ends of which said pins the said flexible strip is urged. 4

5. In apparatus of the kind described, the combination of a casing having an air inlet and an air outlet, a gate device to regulate the amount of air admitted to and discharged from said casing, a casing having a fuel inlet and a fuel outlet, a stemmed valve for the fuel inlet, a spring to urge the fuel valve closed, a push rod in engagement with said stemmed valve and operable to move said stemmed valve in opposition to said urge, a rotatably mounted arm structure operable between two positions and which is adapted for actuation either manually or mechanically, power transmitting devices interconnecting the said arm structure and the said gate whereby upon rotative movement of the arm structure there is rotative movement of the gate, means interacting between the arm structure and the push rod to actuate the latter simultaneously with the actuation of said arm structure, said means consisting of a series of protruding pins carried by the arm structure, each of said pins being adjustable, a set screw to lock each of the pins at the position to which it is adjusted, and a flexible strip fixedly secured to and carried by said arm structure in position between the said pins and the said push rod.

'JOHN J. MAXON.

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