US2841382A - Gas fueled hot air generator - Google Patents

Description

July 1, 1958 A. J. FAucHER 2,841,382

GAS FUELED HOT AIR GENERATOR 2 Sheets-Sheet 1 Filed Aug. 4, 1954 Andrew .1 F aucher IN V EN TOR.

ATTORNEY July 1, 1958 A. J. FAUCHER GAS FUELED HOT AIR GENERATOR 2 Sheets-Sheet 2 IN V EN TOR.

Andrew J. Faucher IGNVl'lON TRANS.

Filed Aug. 4, 1954 ATTORNEY United States Patent @fifice N 2,841,382 Patented July .1, 1.958

I 2,841,382 GAS FUELED nor AIR GENERATOR Andrew J. Faucher, Arlington, Tex.

*Application August 4, 1954, Serial'No. 447,875

' 4-Claims. (Cl. 263-49) 1T his invention relates to gas fueled hot air generators and more particularly to 'such'generators or furnaces especially suited for supplying heated air 'to cotton driers.

The principal object of the invention is to provide a hot air generator which is entirely automatic in its operation and has incorporated therein such safety features as to remove fire-hazards, an important attribute especially when the apparatus is to be used in cotton gins for drying eo'tton,'the safety features inclu ding a gas pressure regulator; automatic control valves responsive to temperature variation (moisture content) of the cotton to be dried, effective to distribute gas flow to burners according to such temperature variations; valve means responsive to suction "in the dryingsystem for extinguishing all burners when'suction diminishes below a predetermined degree.

"Still another object of the invention is to provide a hot air generator exceptionally suited to drying cotton which consists of a plurality .of banksof gas burners, each bank being supplied with fuel through separate conduits having separate fuel control valves for control of fuel to selected banks of burners,the latter.beingprovidedwith a manual and 'an electrically energized pilot. The generator'is connected in'thesystem of conduits so thatsuction'cre'ated by'a 'blower'inthe system will draw'heat from the burners into the cotton drier of the system, which canbe of any conventionaldesign but in any case, the degree'of heat supplied by the burners isautomatically contro'lledby'temperature responsive devices locatedin the conduits through which cotton enters and leaves the drier andwhich areelectrically connected with the valves supplying 'fuel to the burners.

Yet another-object of the invention is to provide a hot air generator installed in acabinet having a side oppositethe .burners closed by doors of screen mesh or other foraminous material so that'air may be drawn across the burners into 'the 'drier system by suction therein, yet preeluding entrance oflint or other readilyignitablematerial which would create-a firehazard. :Moreover, provision'is made for gainin entrance to certain parts of the generator "assembly in the cabinet for repair or replacement while the burners are operating without requiring the opening of the screen doors.

Other objects will appear as the description proceeds when considered with the annexed drawings, wherein:

Figure l'is "a 'front perspective view of a gas fueled hot air generator constructed according tothe invention.

*Figure'il is an end elevational view'thereof.

Figure '3 is a fragmentary rear elevational view'of the cabinet showing the burner assembly and pilot tube in the conduit of the cabinet.

Figure 4'is aperspective viewof one of the burners.

lrFigure 5 is 'a diagram of'a suitable form of electrical wiring usedin the generator, and

:fligure'io is afraginentary diagram of a conduit system incorporating the hotvair generatorand'a cotton drier ion a small 'scale.

Continuing with a more detailed description of the drawing, reference is primarily made to .Figure 1 wherein numeral 10 denotes generally the cabinet in which the assembly is housed and 11, the connector .to which is joined the suction conduit "10a, Figure 6 of the cotton drier 11a, which'latter may constitute any suitable conventional design. The cabinet .is of greater length than height or depth and is separated into a pair of upper, longitudinally aligned compartments A and B and a lower compartment Cwhich is coextensive withboth the upper compartments. The vertical partition 12 separates the compartments A and B and the horizontal partition 13 separates compartment Atrom compartment C. A-door 14, which may 'be solid or of forarninous material, as shown, is hinged at -15 to one end'of the cabinet so that entrance may be gained to compartment A without-opening doors 16 and 17 which provide a closure for the front of the cabinet and which are also foraminous '-so that free passage of air through the-cabinet is permitted. It will become apparent in the course of the description to follow that the doors 1-6 and 17.must remain closed during operation of the generator.

Entering the cabinet 10 through the end wall 18 thereof is a gas pipe 19 in which is incorporatedamanually actuated valve20 actuatable cxteriorly of the cabinet. Interiorly of the cabinet is located agas pressure regulator 21 of conventional manufacture. Thegas inlet pipe 19 is connected to the regulator 21 onone side'and a short pipe22 is connected to the regulator opposite pipe 19 and to the pipe 22, in turn, is connected a T 23. Another short length of pipe 24is connected atone end to the T 23 inalignment-withpipe-22 and at its oppositeend-to an electrically operated control valve25. A burner ;pipe .26 isconnected at one end to the opposite side of the control valve 25 and has'itsopposite end .closed byta'cap .27.

Arranged vertically in the chambers ?B and C or" ithe cabinet It) is a front bank of burners 28. These burners are of identical construction and one is shown in detail in Figure'4. Eachburner consists'of a'tapered leg =.por'-' tion 29, the lower or smallest end'of which is 'flared' at 30 and is formed with an angular flange "31 having.diametrically opposed ears 32. An intermediatelplate 33 inseam 34 havingapertures matching'the apertures Iin-ears .3230 that screws 35 maybe'threaded therethrough totholdithe plate 33 to the flange 31 and .also' to secure .an onterplate 36 adjustably flush with plate 33. The plate 33 has ;a tubularextension 37 on its center which extendszthroughra central opening in plate 36 and the latter :platetis rotatable on the extension so that apertures 38 nnd.39 'in:the plates 33 and 36, respectively, may be relatively 'a'djusted to vary the amountofair mixed withthe gas entering the pipe 29 of the 'burnerthrough the-tubular extension 37.

Theupper orlargest end of the burnerzhasvan annular flange 40 formed :on a right angular :portion 41 thereof, the latter being formedinto a threaded nipple 42. A coupling 43is shown in dotted lines:as'being threaded onto the nipple 42. Cast integralwith the .right angular portion 41 of the burner is'a pair of oppositely extending projections 44. By observing Figure 3.-it'wi1l be seen that these projections, which extend from the sides of the burner bear against the inner sur'face of a horizontal rail 45 and to secure the burners in .upright position relative to the rail 45, asmall rectangular block or plate 47 is set against'the confronting ends of :projections '44 of adjacent'burners and aibolt 4Sisp'assed through the plate -47 and the rail .45 and a wing nut 49 is threaded onto the end of the bolt1(Figure 1i).

'The rear bank of burners 28a is identical with the front bank of burners .and are mounted in a manner identicalito that in-which the strontium-nets :are mounted, hence all of theelementsiofwhich :bothabanks 13f burners are composed bear the same characters of reference except that the horizontal rail from which the rear burners are supported is identified by'numeral 50 in Figure 1."

' The burners 28a of the rear bank are supplied ;with

gas through a horizontal pipe 53 to which "each burner v is connected by a short pipe 54, each having a regulating valve 55 incorporatedtherein. The fuel pipe 53 has one end communicating with one side of a control valve 56 and its opposite end sealed. The control valve 56 is identical to the control valve 25 in the fuelpipe supplying the front burners and to its opposite side is connected 7 a pipe 57 which communicates with the T 23. Hence pressure of fuel'to both banks ofburners is controlled by the single regulator 21.

In order to compensate for the distance between the cotton will govern the action of the first'and second stage H valves, that is, the valves 25 and 56 which control flow of gas to the front and rear burner assemblies, rcspecfront burner assembly and the ignition points of the burners, each has a pipe extension 58 (Figure 3) screwed into the coupling 43 whose end terminates in the same plane with the ends of the couplings 43 of the rear bank of burners whose close adjacency to the rear wall of'the cabinet 10 precludes necessity for pipe extensions such as theextensions 58 of the front burners. 1 Connected also to the regulating valve 21 by means of a small tube 59 (Figure 1 is a'gas pressure regulator 60 whichcontrols gas pressure to a pilot control valve 60a. A manual cut-off valve 61 is incorporated in the tube 59 for closing off fuel therethrough whennecessary or desirable; A pressure gauge 62 is connected to one side ofthe regulator 60 and to'the opposite 'side of valve 60a.

' rated in the pipe 64. Connected to the other leg of the T 63. is a similar pipe 67 which communicates with a manual pilot 68. This pipe also has incorporated therein aregulating valve 69. r a

The-manual pilot 68 is in communication with a .per-

' forated .distributing pipe 70 underlying the rear flush ends of the burners 28 and 28a as shown in Figure 3. The distributing pipe 70 has a series of perforations 71 which are smaller than adjacent perforations 72 .which latter are made larger to accommodate the rear burners 28 which are on a higher plane than the burners of the front bank. a v a 7 It has been; stated that the invention is installed in the conduit system 10a of a cotton drier 11a. The fan or bloweris indicated at 72a in Figure 6 but may be located at any suitablerpoint in the conduit system of the drier 11a' in order that the suction of the fan or blower of thesystemwill draw air through thecabinet 10 and across the burner assemblies 28 by'means of the connector .11 by which the generator is connected into the system. .It is necessary thatlthere be provided some means to insure that function of the burners depends upon suction through the. generator. In. other words, the burners will not operate unless the fan 72a is in operation. With this. in view, an air switch 73 is pro vided whichis in communication with a suction tube 74 by means of a smaller tube .75 (Figure l), the suction tube74 extending into theconnectorll of the cabinet 10 cient to actuate? the airswitch 73, thus to extinguish the I Referring tothe electrical system illustrated in Figure 5 burners in :the manner to be presently explained.

it will be observed that arelay 76'of any suitable design is provided to which are connected the air-switch 73; automatic pilot 65; pilot valve '60, burner'valves'25 and 56; an ignition transformer 77 and a pair of thermo stats or temperature control units 78 and 79.

The temperature control units 78 and 79 are located in the cotton ducts 10a and 12a,(Fig. 6) through which cotton enters and leaves the drier. control units, are of well known. manufacture, one. being arranged in the intake duct 10a of the cotton drier while the other isdisposed in the cotton drier outlet duct 12;:

thereof, as indicated by reference numerals:78;and 79,- respectively, in Fig. 6.' The control units'78 and 79'may be substituted by moisture sensitive elements of wellknown manufacture orsuch elements may function in conjunction with said control units in such manner that the moisture content as Well as the temperature of the tively. For example, when the temperature of. the cotton reaches 178 F., the temperature control '78 will cause l valve 25' to close, thereby extinguishing the front burner assembly, An increase of 2 F.,'in the temperature of; the cotton will cause the temperature control 79 to func: tion to actuate the second stage valve 56, tofextinguish the rear burner assembly. v

In operation, the various regulator valvessuch'asthe masterregulator 21; valves 52 and of the burners 28; valves 61, and 69 of the pilots 65 and 68 are all pre-. set to predeterminethe flow of fuel to the burners and' pilots. The doors 16 and 17 of the cabinet are closed and the fan or blower 12a of the cotton drying system is started. Suction of thefamcausing a draft of air through the cabinet 10 and over the. burners 28fwill, create a suction in the tube 74 in the duct connector '11 and which will actuate the air switch 73 to closedposi tion. ,The main gas inlet valve 20 is opened and the,

fused disconnec't 80' (Figured) is closed and after a period 'of one minute, therstarting switch 81 is closed which energizes the electric pilot 65 through the relay 76 and ignition transformer 77. r

A suitable type of electric pilot is found. in neapolis-Honeywell flame rectifier pilot which is shown in Figures 1, 3 and 5; Since the design and function of this pilot is conventional, a description thereof per sc is not considered necessary. Gas suppliedby the manual pilot 68 is ignited by the automatic pilot 65 whichllatteri 'ignites both banks of burners.

Air drawnthroughthe cabinet 10 is heated by the burner assembliesz28 and 28a and conveyed to the'cotton drier. As the cotton passes through the ducts leading to and from the drier, the

temperature controls :78 and 79 function to vary the. a amountof fuel passing through the valves 25 and56. according'to the moisture content or temperature of the,

cotton, thus varying the degree of heat generated by the burner assemblies .28 and 28a. As stated previously,

when the temperature of the cotton rises to a'pr'edetcrmined degree, valve 25 will be closed toextinguish the front bank of burners and a slight increase in temperature as indicated by'thecontrol 79, valve 56 will be closed to extinguish the companion bank of burners.

If, at any time the suction in the. drying. system shouldclose or be interrupted for any reason, such asiby the stoppage of the fan therein, the air switch 73 willautomatically cause'the .closing of valves 25 and 56, thereby; cutting off all fuel to'the burner assemblies '28 and 2841,;

aswell as to the manual pilot 68 through the medium of regulator and valve 60a. This latter valve which is of conventional manufacture,,is also made. to closeinthe event the flame of the electrical pilot is extinguished for any reason. In order 'to' immediately determine whether or notthe airswitch 73 is' funct ioning, a lamp 83 (Figure 5) is incorporated in'thc circuit These temperaturc which is illuminated during closed position of the air switch.

in order to extinguish the burners 28 and 28a and electrical pilot 65 in a manner other than under emergency conditions, the switch 82 is actuated Whose function in relation to the burner valves and 56 is self-evident in the electrical diagram shown in Figure 5.

While the hot air generator has been described chiefly in association with a cotton drier, it is clearly apparent that it has ready application in other fields Where heated air may be required, such as in the heating of buildings and many other adaptations.

Maniiestly, the construction as shown and described is capable of some modification and such modification as may be construed to fall within the scope and meaning of the appended claims is also considered to be within the spirit and intent of the invention.

What is claimed is:

1. In combination with a duct through which air is constrained to pass, a hot air generator comprising a cabinet having an air passage in communication with said duct an air previous screen through which air is influenced into said air passage and duct and adapted to intercept inflammable particles entrained in said air, a gas fuel line entering said cabinet, a gas pressure regulator in said line, a front and a rear gas supply pipe disposed in longitudinal parallelism in said cabinet and communicating with said regulator, a series of longitudinally spaced and vertically disposed front burners communicating with said front pipe, a series of rear burners communicating with said rear pipe in parallelism with said front burners, said burners terminating in the same plane in the air passage of said cabinet, a manual pilot for said burners, an electric pilot, an electrical circuit, a control valve for each of said gas supply pipes and connected electrically in said circuit, remote temperature responsive means for actuating said control valves in accordance with changes in hot air requirements of said burners, an air switch in said circuit and means disposed in said air passage and communicating with said air switch to actuate the same upon cessation of air flow through said cabinet, to close said control valves to extinguish said burners.

2. In combination with an air duct through which air is passed, a hot air generator comprising a cabinet through which air passes into said air duct screens through which said air is passed preliminary to its passage into said duct to intercept inflammable particles entrained in said air, a first group of gas burners in said cabinet in the stream of air entering said air duct through said cabinet, a second group of burners forwardly of and adjacent said first group of burners, a manual pilot for said burners, an electric circuit, an electrically ignitable pilot in said circuit, an individual gas supply pipe for each of said groups of burners, a main gas supply pipe communicating with said individual gas supply pipes, a pressure regulator in said main supply pipe, a control valve in said circuit for each of said individual supply pipes, an air actuated switch in said circuit held in closed position by suction of air through said cabinet and across said burners, said air switch being effective, upon cessation of said suction to close said control valves, and temperature responsive means in said air duct and having electrical connection with said control valves and said electrically ignitable pilot to vary the amount of fuel delivered thereto in accordance with temperature changes in said air duct. pparatus for generating hot air for delivery into a district. mg duct having an air moving means therein, said apparatus comprising a cabinet connected to said distributing duct and through which air is drawn by the air moving means of said duct means through which said air is constrained to pass in its course to said distributing duct for removal therefrom of combustible materials entrained therein, gas burners disposed in the stream of air passing through said cabinet, a gas supply pipe for said burners, a pressure regulator in said gas supply pipe, an electric circuit, a gas control valve in said circuit and communicating with said gas supply line, a manual and an electrical pilot, the latter being connected in said circuit for igniting said manual pilot and said burners, an air switch in said circuit and held closed by suction created by air drawn through said cabinet by said air moving means, means connecting said air switch electrically with said gas control valve to close the latter upon cessation of said air moving means an air suction tube disposed in the air stream forwardly of said burner and connected to said air switch and in which suction is established and maintained by said air moving means of said air distributng duct to mantain closed position of said air switch, and means located in said distributing duct and responsive to changes in temperature in said duct to actuate said control valve and vary the gas flow to said burners according to temperature requirements in said distributing duct.

4. Apparatus for heating air in an air distributing duct having air moving means therein, said apparatus comprising a cabinet having means for connecting the same to said distributing duct and through which air is caused to be drawn into said duct by said air moving means screens through which said air is constrained to pass for the removal of combustibles entrained in said air, a series of gas burners located adjacent to said connecting means, a gas supply pipe for said burners, an electrical circuit, a gas control valve in said circuit and communicating with said supply pipe, temperature and moisture responsive means in said duct for actuating said control valve to supply gas to said burners in accordance with heat requirements in said duct, means for igniting said burners, an air switch in said circuit and connected with said control valve and means for actuating said air switch to close said control valve when air ceases to pass through the connecting means between said cabinet and said air distributing duct.

References Cited in the file of this patent UNITED STATES PATENTS 1,164,058 Bayne Dec. 14, 1915 1,463,615 De Camp July 31, 1923 1,517,463 Rose Dec. 2, 1924 1,811,980 Smith June 30, 1931 2,129,059 Herbster et al. Sept. 6, 1938 2,211,631 Sweeley Aug. 13, 1940 2,212,352 Plein Aug. 20, 1940 2,453,382 Pietsch Nov. 9, 1948 2,470,996 McGrath May 24, 1949

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