US2625992A - Multiple group gas burners with independent fuel and secondary air supplies - Google Patents

Description

Jan. 20, 1953 2,625,992

V. S. BECK MULTIPLE GROUP GAS BURNER-3 WITH INDEPENDENT FUEL AND SECONDARY AIR SUPPLIES 2 SHEETS-SHEE'1 1 Filed June 30. 1949 FIG.3.

Jan. 20, 1953 v. s. BECK 2,625,992

MULTIPLE GROUP GAS BURNERS WITH INDEPENDENT FUEL AND SECONDARY AIR SUPPLIES FiledJune 30.1949 ZSHEETS-SHEET2 FIG.6.

TM i 0 C 6 0 0E H r E o m r t Z m 1: 1!- c n v 7 a 0 6 I a a 7 z a w m B m T m .f. n 0 C Patented Jan. 20, 1953 MULTIPLE' GROUP GAS BURNERLS WITH INDEPENDENTFUEL'AND EA'IR SUPPLIES "SECONDARY Vernon .S. Beck, St.,Louis,. Mo. Application J and-30, 1949;"SeriaPNo. I02i370' 3- .Claims.

invention :relates to 'gas--=burners of \the- "modulating" variety for heating and power ;sys-

tems'.

:Briefi'y, rthe-rinvention consists win a multiple 1 gas :-':burner arrangement in a convenient integrally'ibuilt unit'whereinzthe burners for 'a given :ffnrnace are "sectiona'lized intotremovable groups which are independently-supplied *with :primary f-heatingrequirements under varying conditionso'f 'heatloss irom the region'being-heated; -A thermostat responsive to a desire'dtemperature,through a sequence relay -circuit,-controls the sequence of starting of the burner groups. Thus onlyasufiicient'number 'ofburner'groups is "in operation at any one time, operating atbest efficiencyto supply the'existent heating load; and in addition, when "it is necessary to bring more than one group of burners into operation, the respective group's'are sequentially introduced 'so astoeliminate the concussion which ordinarily occurs when all of the burnersof 'a'furnace of substantial 'size-are 'ignited'at'onee. Thus the inventionresults in automaticaly obtaining -higher operating efiiciencies under all load conditions from-a-unit of the-type described. 'It-also'results ina'much quieter "modulated control for bringing burners into operation. Qther features willbe in part apparent and in part pointed "out'hereinafter;

'The'invention accordingly comprises the elements and combinations 1 of elements, features of construction and manipulation, and arrange- -merits of parts which will "be exemplified in the structures hereinafter dscribedgandthe scope of the applicationpf which will be indicated inthe iollowing- 'claims.

In the'a'ccompanyingdrawings, in'which' one of various possible embodiments of the inventionis illustrated "Figii 'is'-a'-front-end view-01a gas "burner unit enribodyir'rg my invention;

Fig. a cross section-"view "on lineal-2 01! Figs. Land -3;

Fig; "'3 'ishorizontal' section 'taken' on:1ine "3- 3 of Fig.2;

Fig. 4'is-a vertical sectiontaken' online-A-J of Fig.2;

Figfi5 is a plan view of Fig. 2 but showing certain burner heads removed;

Fig.6 is a fragmentaryde'tail' plan-viewoi severalburner' heads ItFig. H .is ea :vertical :section taken" on line of Fig-"6 and,

Fig'nsisaa'wiring diagram.

-Simila-r zreference characters indicate correspondingi parts throughout :the several Y views 1 of the drawings.

'Whilethewpresent invention is describedfor burnersiin an insertable unit'used in connection "with-steam :heatin'g boilers, it will beunderstood 1 that the invention is useful ffor-hot waterboilers and: also for=warm air heating-furnaces.

In most-prior heating systems employing gas burners, all burners were brought into-action at thersame time, which: caused a I considerable iconcu'ssionfand" vibration as "all of rthe -burhers': became'ilighte'd, particularly: in cases of large-capacity burners. One 1- solution to :the problem has been theprovision v of slow-opening supply valves. These supplied'all burners at onceand were used -for-contro1ling the volume of gas not only "for starting but :modulating for load requirements. In" the latter connection, suchvalves were-unsatisfactory because the range of change in con"- trolwas'ext-remely-limited. For-example, by re- "ducing gas-pressure from" four ounces'to one ounce (-an= extreme*for most burners) a reduction'of capacity of only 50% canbe attained, which under many circumstances results in waste. In some cases sequentiallyignited groups of burners .have been employed with air supplieswhich were individual to the groups, 'butthese were not:built into units for convenient application to various .furnaces and required a substantial amount of special installation work. By means ofthe presentinvention, acon-venient unit is provided having theabilityl to be applied to match various load requirements oil-anyof-a wide variety of heating plants. Moreover, vused either :withoutor .in conj unction with slow- .actingxvalves,.thereby extendingits field of use- .fulness.

Referring -now m0re:particularly to- Figs. 1-'5, there isshownat numeral! an enclosed rectangular base which .forms an air box unit adapted to be placed under. anyof fa widewariety of boilers. This 'box hasa flat top- 3 and by .means of ,baflies. 5 .and. I is divided into three ,plenum..ch'ambers;9, ll and-i3, which receivevair through forwardcontrol doors I5, 1| 1 and I9, respectively. The .top 3 .is provided with longitudinal .outlet slots 21 (for. issuance oisecondary air. Each slot 2! transverses all of .the plenum chambers 9, I andl3. .Thus a part ofeachslot 2 I formsan outlet for secondary air from one of 'theplenum chambers. Between the slots .21 'in the'top. 3 are" lociatedsocketeforming openings! 2 3 ikarth'e reception of'burner assemblies 25. The

the present invention may :be

ential under 4% p. s. i.,

a small differential under character of each burner assembly is shown in Figs. 6 and 7, and comprises a top manifold 21 having outlets 29 with passages 3| for rising secondary air. Each manifold 21 is on the top of a mixing pipe 33 having a Venturi inlet 35. This inlet is adapted to receive gas from nozzles 31 and also primary air which sweeps into the venturi with the gas from these nozzles. The burner assemblies 25 are removable and interchangeable with respect to the socket-forming openings 23. The entire number of manifolds 21 of the burners 25 may be considered'to be a removable firing platform, removable burner by burner, and. held in position by gravity above the top 3, sectionalized according to the groups of associated plenum chambers 9, I and I3, into which their lower ends extend. Thus (Fig. 2), all of the air for the section A of burners is supplied through the plenum chamber 9; all of that for section B through the plenum chamber I: and all for section C through the plenum chamber l3. One advantage of this construction is that no group of burners becomes starved of air,

since all of the air cannot short-circuit through any one group of burners.

The gas supply for the burner groups is also sectionalized. This is done by sectionalizing the nozzles 31 into groups a, b and c. The group a of nozzles 31 is located in branched manifold pipes 39, extending from a lateral header 4| supplied by an inside leader 43. The group b of nozzles 31 is located in branched manifold pipes 45, extending from a lateral header 41 supplied by an inside leader 49. The group of nozzles 31 is located in branched manifold pipes 5 I, extending from a lateral header 53 supplied by an inside leader 55. All of the leader pipes 43.49 and 55 are supplied from a main gas line 51 to which they may be conveniently attached. As shown in Fig. 5, a pilot line 59 from the main supplies two pilot burners 6| for the section A; pilot line 63 supplies two pilot burners 65 for the section B; and a pilot line 61 supplies two pilot burners 69 for the section 0. This arrangement allows for convenient insertion of the headers 4|, 41 and 53 and manifold pipes 39, 45 and 5| in the respective plenum chambers 9, H and 3 and convenient application of the burner heads above these chambers. Grouping of the heads is automatic, even when applied indiscriminately.

In the pipes 43. 49 and 55 are manual shut-off cocks 1| and suitable pressure regulators 13; also electrically operated gas valves 15, 11 and 19, respectively. These valves 15, 11, 19 are under control of boiler-pressure-operated switches 8| 83 and 85 (see Fig. 8). The switches 8|, 83 and 85 are opened and closed in response to predetermined pressures of the heating boiler which the burners serve. Thus, forexample, when the boiler pressure drops to a small difierent'ial' under 5 p. s. i., switch 8| will close, thus, energizing valve 15 to open; when it drops to a small differswitch 83 will close and energize valve 11 to open; and when it drops to 4 /2 p. s. i., switch 85 will close and energizevalve 19 to open. When one of the switches 8 83 or 85 closes, it energizes the respective gas valve 15, 11 or 19 which opens promptly, although these valves may be of the slow opening type if desired. In conventional gas fired systems any gas valve control used for controlling a set of burners is commonly arranged to shut off the air damper door for when the gas valve is closed, so

such burners as to prevent undue cooling of the'heating surfaces between firings. That practice is followed in the present construction so that door I 5 closes when valve 15 is closed; door I1 closes when valve 11 is closed; and door |9 closes when valve 19 closes. Means for this purpose being common and of a wide variety of forms further details are unnecessary. t

A typical wiring diagram is shown'in Fig. 8, in which 81 indicates a thermostat in a main line circuit 89. It is by means of this thermostat 81 that calls are .made automatically for heat. When the thermostat 81 is satisfied, the circuit 89 is broken; otherwise it is closed. Circuit 89 serves a circuit 99 through a transformer lfll. This circuit 98 supplies a circuit 9|, which includes the pressure-controlled switch 8| and electrically operated gas valve 15 controlling section A and also the motoring elements of a time delay switch 93. Thusif the circuit 9| has been prepared by previous closing of the pressure switch 8|, valve 15 for section A will open when the thermostat 81 closes in response to a predetermined reduction in temperature in the space being heated. This also energizes the time switch second time delay switch 91, serving to close in a control circuit 99. Therefore the circuit 99, if prepared by the pressure-controlled switch 85. causes valve 19 to open a suitable interval of time after valve 11 has opened.

In the circuit 9| are pilot safety switches I93, which are closed as long as pilots 9| are burning; in the circuit 95 are pilot control switches I05 which are closed as long as the pilots 65 are burning; and in the circuit 99 are pilot control switches I91 which are closed as long as the pilots 69 are burning.

Operation is as follows:

Assume that all pilot lights BI, 65 and 69 are burning and that thermostat 81 calls for heat, thus closing circuit 89 and energizing circuit 99.

If upon a call by the thermostat 91 the pressure is under a suitable differential below 4 p. s. i., all of the pressure-controlled switches 8|, 83 and have prepared their circuits 9|, and 99, respectively. Valve 15 for section A opens immediately, thus lighting section A. Since time switch 93 is energized, it energizes circuit 95 after a suitable interval, at which time the prepared circuit 95 is energized and valve 11 opened, thus lighting section B. This also energizes the time switch 91, which after a suitable interval energizes the prepared circuit 99, thus opening valve 19 of section C.

In the event that the call made by the thermostat 81 is under pressure conditions above a small increment over 4 /2 p. s. i., circuit 99 will not be prepared by any closure of the pressure-controlled valve 85. Hence valve 19 will never open. This means that the heating load'under the prevailing conditions can be supplied without all burners being in operation and it is taken care of by lighting of sections A and B in sequence.

In the event that the call made by the thermostat 81 is under pressure conditions above a small increment over 4% p. s. i., circuit 95 also will not be prepared by any closure of the pressure-controlled switch 83. Hence valve ll will never open. This means that the heating load under the prevailing conditions can be supplied by operation of section A only.

When the thermostat 8'! ceases to call for beat. all circuits become deenergized and all of the valves i5, fl and 19 close, thus turning off all burners at the same time. Since no condition of concussion or vibration is associated with turning all burners oil at once, no sequential operation is used in this connection.

Thus it will be seen that a double modulation control is obtained. First, the burner sections light in sequence, regardless of how many sections are required to carry the load. Second, only such a number of sections is called upon to light as are required to carry the load. Moreover, each section when lighted receives its independent supply of primary and secondary air, unafiected by the requirements of any other section. The result is that the burners operate to start quietly and to supply the load efficiently under all conditions.

It may be noted that the air box I is installed with the air inlets 15, ll, [9 located at the front end of the boiler served, that is, the end farthest from the flue connection. Thus when less than all of the burner groups are ignited practically all of the boiler heating surfaces are reached by the resulting hot gases. It is also clear from the drawing that the box I with the contained and attached parts is in its construction independent of any furnace walls or settings, being in the form of a self-contained unit which may be factory-assembled and shipped for simple insertion in any of various furnaces.

It is to be understood that, although the invention has been described as built for a triplegrouped arrangement, it also may be built for other group multiples, such as two, four, five et cetera.

Reference is hereby made to my copending U. S. patent application, Serial No. 206,438, filed January 17, 1951, for Modulating Gas Burner, containing claims directed to the control system set forth but not claimed herein.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. An integrally built burner unit for insertion in furnaces comprising an enclosing air box having a top and inside baffies dividing the box into separate plenum chambers connected individually with openings through one end wall of the box, individual draft controls in said openings, a fuel header in each plenum chamber communicating with the outside of the box, pipes branching from the headers and located by groups in the respective plenum chambers and having fuel outlets, said top of the box having socket-forming openings above said fuel outlets, removable gravity held burners having mixing pipes insertable into said socket-forming openings for cooperation with said fuel outlets and. arranged to accept 6 primary air from the plenum chambers along with fuel from said outlets, the burners aving abutting top manifolds including secondary air passages, said top having additional openings for the release of secondary air from the plenum chambers through said passages in the manifolds to combustion regions of the burners above the box, said abutting manifolds forming a sectionalized firing platform held by gravity in spaced position above said top, said burners being individually removable by lifting from said platform.

2. Apparatus made according to claim 1, wherein said openings in the top for the secondary air are constituted by slots each of which traverses all of the plenum chambers, and wherein the remainder of the socket-forming openings are located in the top between said slots.

3. An integrally built burner unit for insertion in furnaces comprising an enclosing rectangular air box having a top and inside bafiles dividing the box into separate plenum chambers which extend laterally of the box and are connected individually with openings through one end wall of the box, individual draft controls in said openings, a laterally extending fuel header in each plenum chamber communicating with the outside of the box through the end Wall having said draft controls, pipes having fuel outlets and branching from the headers and extending longitudinally of the box and located by groups in the respective plenum chambers and having fuel outlets, corresponding branches in the various plenum chambers being collinear whereby said fuel outlets are arranged in rows, the top of the box having rows of socket-forming openings above the rows of fuel outlets, removable interchangeable rows of gravity held burns having mixing pipes insertable into said socket-forming openings for cooperation with said fuel outlets arranged to accept primary air from the plenum chambers along with fuel from said outlets, the burners havin abutting top manifolds including secondary air passages, said top having additional openings for the release of secondary air constituted by longitudinal slots each of which is located between rows of burners and traverses all of the plenum chambers, said abutting manifolds being in rows parallel to said slots and forming a sec=- tionalized firing platform held by gravity in spaced position above said top, said burners being individually removable by lifting from said platform.

VERNON S. BECK.

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

UNITED STATES PATENTS Number Name Date 1,447,337 Bitgood Mar. 6, 1923 1,918,265 l-lartwig July 18, 1933 1,960,609 Werner May 29, 1934 2,011,283 Huff Aug. 13, 1935 2,139,344 Anderson Dec. 6, 1938 2,142,014 Zink Dec. 27, 1938 2,196,282 Voorheis Apr. 9, 1940 2,231,391 Martois Feb. 11, 1941 2,286,296 McGrath June 16, 1942 2,300,560 Faber Nov, 3, 1942 2,470,996 McGrath May 24, 1949

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