US2603882A - Cooling system for industrial ovens of the conveyer type - Google Patents

Description

' MAYER C. F. COOLING SYSTEM FOR INDUSTRIAL OVENS OF THE CONVEYER TYPE Filed May 20, 1948 4 Sheets-Sheet 1 INVENTOR. I BY C424 fi-Mnysk J ly 22', 1-952 c. F. MAYER .COOLING SYSTEM FOR INDUSTRIAL OVENS OF- THE, CONVEYER TYPE File d Bay 20'; 1948 4 Sheets-Sheet 2 "INVEIIIVTORL 6 w; fiMnYsk flrroxazvsys I July 22, 1952 Filed llay 20. 1948 C. F. MAYER COOLING SYSTEM FOR INDUSTRIAL OVENS OF THE CONVEYER TYPE 4 Sheets-Sheet I5 2763; C494 MAYER" c. F; MAYER 2,603,882-

COOLING SYSTEM FOR INDUSTRIAL I OVENS OFTHE CONVEYER TYPE v I 1 I 4 Sheets-Sheet 4 Jpl 22,1952

Filed May .20. 1948 v By CkeZFMnne-e Patented July 22, 1952 COOLING SYSTEM FOR INDUSTRIAL OVENS OF THE CONVEYER TYPE Carl F. Mayer, Lakewood, Ohio Application May 20, 1948, Serial No. 28,078

. Claims. (01. 34-66) lhisv invention pertains to industrial ovens of the conveyor type that are used for drying cores or molds, or for heat treating articles of manufacture, or for drying or baking surface coatings thereon, such as enamel.

- 'In industrial ovens of the conveyor type, provisions are usually made for cooling the work to convenient'handling temperatures as the work approaches the unloading station, some consideration being given, also,.to the comfort of the workmen who remove the work from the con- My present invention relates to cooling means for industrial ovens, particularly of the vertical type, and its principal object is to provide a cooling system that is reliable and efficient in cooling the work .and that maintains a temperature atmosphere in the region of the unloading station.

Another object of my invention is to provide a "cooling system for industrial ovens that includes refrigeration means by which the cooling fluid is chilled.

. A related object is to make the refrigeration means variable as to its cooling capacity, and auxiliary to the air supply for the cooling system, so that artificial cooling may be dispensed with when the natural temperature of the aircis sufficiently low to serve the purpose, or so that, the eflect of the refrigeration means may be modifledjto attain the desired drop in temperature of the air.

,Another object of the invention is to provide cooling equipment fora conveyor type oven by whichthe cooling fluid is well distributed and ap-v portioned along the-path of movement of the work as the latter approaches the unloading station, and by whichthe fluid is promptly with- I drawn after passing about the Work so that any obnoxious .odors or injurious gases given off by p the work-during its passage through the cooling zone are quickly and effectively disposed of. Another and related object is to extend the area of the fluid withdrawing means beyond the cooling zone and into the region of the unloading station,,thereby to render the atmosphere in which the operators work more wholesome and comfortable.

A further object is to provide air impelling means opposite the unloading door or opening of the oven for supplying fresh air immediately in the region of said door or opening.

A still further object of the invention is to provide the cold air supply duct of the system with a seriesof outlet passages that are stepped along the path of movement of the work and which openings are equipped with regulating means or shutters by which the effective cross sectional area of said passages may be varied thereby-to better distribute and apportion the cooling fluid along said path. 7

It is another object of my invention toimprove the operation of the oven, generally,by incororating an injector inthe exhaust flue or the oven that is supplied with motive fluid fromthe discharge end of the cooling system. V r 1 Because of the character of the invention itself, and the huge size of ovens of the kind in which it is incorporated, I have illustrated the invention in a'somewhat diagrammatic way in the accompanying drawings; and as I proceed to describe the invention by reference thereto, utilizing'like reference characters to designate like parts in the several views, objects and advantages additional to those'above enumerated will become apparent.

In the drawings, Fig.- 1 is an elevational'view of' an industrial oven of the vertical type equipped with the cooling system of my invention, the oven being viewed from the unloading side; Fig. 2 is an elevational view of the oven as though looking from the right of Fig. 1; Fig.3 is a similar view, looking from the opposite side of Fig. 1; Fig. 4 represents a vertical section through the oven, substantially on the line 4 4 of Fig. 1, and Figs. 5,6 and 7 are horizontal sections, taken on the respective lines 5-5, 6-6" and 11ofFig.1. The. present oven comprizes a front wall I, a rear wall 2, side walls 3 and 4, and a top wall 5.- The parts of these walls that enclose the heated chamber A in which the work is dried or otherwise treated, are, in practice, constructed of sections of suitable size, each consisting of a large slab or flat body of insulating material enclosed in sheet metal, and the. sections are suitably joined and held together within a framework that is made up of standard structural elements such as channels, I-beams, etc., theiramework being designated generally by the reference character ID. The oven structure rises from the bottom of a pit II of suitable depth below the level of the floor l2.

The bottom of the heated chamber A is something more than head height above the floor I2, and below said chamber the front wall is fabricated of metal plates N that are spaced apart vertically-to provide therebetween a loading door or opening B, while the corresponding portion of the rear wall is made up of similarly arranged metal plates l5 between which is anunloading door or opening C.

are large sprocket wheels 58 about conveyor chains 6! are engaged. The sprocket {wheels are rotated in the direction indicated Extending laterally from the sides of the oven structure, at about the level of the bottom of the heated chamber A, and constituting parts of the general framework it, are platforms and 2!.

In the plane of these platforms, a bridge 22 extends transversely through the oven and supports a heater 25, desirably or the gas, liquid fuel or powdered coal burning type, and constructed to provide a'fluid circulating space, according to prior practice. Rising from the rear edge of this bridge, in suitably spaced relation to the wall 2, is a heat insulating partition 26. which "may be constructedoi metal plate, that 21 is a wall,

rises from the top of the heater 25 in forwardly;-

spaced relation to the partition 25 so as to define therewith a so-called recirculating (111013 28 that opens at its lower end into the fluid circulatin space of the heater 25. Shown as rising from the side of the heater opposite the recirculatingduct. are two heat supply ducts 3%. Obviously, one broad supply duct mightbe utilized in place of -;the two shown. Supported upon the platform 2| .is alheatsupplyian on-blower 32, shown as adapted to be driven, through suitable connections 33, by an electric motor 34. -;'l he inlet-of ,-the fan or blower 32 is placed in communication;

through aconduit 35, with thef luid circulating mm the fluid circulating space of the heater 25QandldeIiVered t the iducts 'sil from which it will be projected substantiallyhorizontally across aipartof theiheated chamber A that maybe .termed the drying or treating area. .Also by .theflaction of the fan or blower 32, suction is :created within the fluid circulating space of the a :.heater 2 5 so as to withdraw air..from the top portion of the heated chamber A through the recirculating duct 28. .It may be mentioned,

however, that in the operation of the heater, a

certain amount of atmospheric air is continually drawn in and added to that returned from the heated chamber, and this surplus fluid is withdrawnirom the taper theoven through ducts lfl'lthat'open through the rear wall 2 adjacent the top of the oven and communicate with a stack 4|.

Included in the general .framework it, near the top of the oven,yar'e platforms Mend "that support the respectivebearings 46 and 4! .on opposite sides of the-oven. Disposed transversely of the oven and extending outwardly throughiholes in the side walls 3" and 4 is a shaft 5%! that is'journaled in said bearings, and secured to the shaft beyond the bearing l'i isa gear -EBthat meshes with .a driving pinion 54,. This pinion constitutes a part of drivinglmechanism designated generally by the reference numeral 55.. ,Fastened to the shaft .56, inside the oven, and iniclose proximity to the side walls 3 and B,

by .the arrow in Fig. 4 to propel the chains upwardly adjacent the'front wall of the oven and downwardly adjacent the rear wall thereof.

which endless rear wall 2.

the cores, molds, or other articles .th'atfare to be dried, baked or heat treated.

The work descends adjacent the rear wall 2 through what may be termed the cooling area ,or zone enclosed by the partition 26 and the adijacentiportions of the rear and side walls of the oven. Supported by the framework on the outer sidejof the rear wall 2, substantially throughout the area of the cooling zone is a cold air supply duct 80. Passages 81 lead therefrom through the Flow of air through the passages 8! is adapted to be controlled by dampers 84 that are adjustable .by any suitable means.

Thus, the supply of coldia'i-rto the cooling zone may be. properly regulated and distributed .from top to bottom thereof. Airtis conveyed tothe top of the duct '86 bya conduit 85 .thatleads from the outlet of a cold .air supply fan or-blower 86, mounted on a platform .-81 that extends la'terall'y from the oven beyond the side .wall 4 a suitable distance below the plane of -the.p1atforms 4!; and 45. The inlet of the cold air'fan or blower 86 communicates through an outwardly flaring casing 88 with the evaporator housing 89 of refrigeration apparatus designated generally'by'the referenceinumeral 90.

It will 'be understood that the evaporator housing 89 has an opening or openings through whichatmospheric airis .drawn by the action of the'fan or blower 86. The evaporator is made up of a plurality of units that may individually be thrown into and out of operation wherefore the'cooling ,.capacity of the refrigeration. apparatus may be varied at will. Therefore, refrigeration may be supplied as required to;chill the air to the desired degree of coolness; or .all units of the, evaporator may be rendered ineffective when the atmospheric temperature is low enough to need, no chilling.

.Situated along the outer sides of the wallst and iiare recovery ducts 95. .These ducts areof substantially the same dimension, in a directionfrom front to rear ofthe oven, as thefciooling zone; and they extend upwardly from about theplane of the platforms '29 and 2l'to an elevation above the top plane of the cold air supply duct 83 where they curve 'rearwardly and join a .transverseconduit 9B. vAs best shown in Fig. 6, the Sconduit'QS extends forwardly, adjacent the wall 4, to and communicates with the inlet, of anexhaust fan or blower 100. This fan or blower isoperated, through driving connections .101, by an electric motor I02. This equipment is mounted-on the platform '81, along with the reirigeration apparatus and the cold air supply fan or blower. A conduit 1B5 leads from the outlet .of the exhaust fan or blower lflfl-rearwardly andupwardly to where it hasconneetion with a pipe Hi6 which extends through theadjacent side of the stack 6|. Inside the stack, .the pipe is extended upwardly, axially of thestack, and

operation a suction will be createdth'atf will enhance the natural draft of the stack ilLand thus more effectively draw off the surplus gases from the top of the oven throughthepreviously mentioned passage .40. i

F'or the same and obvious reason that the cold air supply-duct 80becomes progressively smaller in cross section as it extends downwardly along the cooling zone, the duct's'95 taper downwardly;

and-these 'latter 'ducts communicate with the cooling-zone through passages. 0. 1

Attention is? particularly directed to the fact that the recovery ducts 95 extend below the cooling zone, and"'substantially to the plane ofithe platforms 20' and! l,' as casually mentioned hereinbefore. This insures "withdrawal" of heated gases and odors "given 'oif'byi the 'work'in the region of the unloading opening Also reclov= ered by the extended portions of the ducts-95 are 'hotgasesthat may drift down from the cooling area or zone, However, to insure the maximum of comfort-ts the-workmen employed at the unloading station, I seal off the spaceinwardly of said opening from the portion of the oven beneath the bridge 22 by a heat insulating baffle wall-J1 [5.3 -'This ba'file wall extends in a transverse direction from one to the other of the side wallsof the oven and vertically between said bridge 22 and the level of the floor [2;] This wall may be provided with one or more openings H6 that are occupied by ventilating fans H1, driven by electric motors H8. 'The air supplied to these fans tends to check .anydownward' drift of heated gases from above, and cools that portion of :the unloading zone that is faced by the workers in front of the opening C;

vFrom the foregoing description, it will'be seen that my invention provides a cooling system for industrial ovens of the conveyor type that efi'ectively'cools the work as it approaches the unloading opening or station and maintains a comfortable atmosphere in the region gof suchopening or station. Since the work is cooled to a proper handling temperature and hot obnoxious ases are eliminated from the vicinity of the unloading station, the workmen will naturally perform more efiiciently, and processing of the articles will be expedited. The system, as herein disclosed, also provides for regulating the temperature of the cooling air below that of the atmosphere, and for effecting proper distribution of said air along the course of movement of the work.

Having thus described my invention, what I claim is:

1. A cooling system for vertical industrial ovens of the conveyor type. which ovens are characterized by a walled structure having an opening providing an unloading station and enclosing a space above said station serving as a cooling zone and through which zone and past which station a flight of the conveyor descends; said cooling system comprising means adjacent the Walled structure above said opening and substantially coextensive in area with said zone for delivering cooling air to the zone, and means adjacent the sides of the walled structure and extending downwardly from the top of the cooling zone and continuing through the region of the unloading station for withdrawing gases from said zone and region simultaneously with the delivering of the cooling air to said zone, the last mentioned means exhausting said gases from the system, a baille wall within and extending transversely of the walled structure for closing off said region from the adjacent portion of the interior of said structure, said baffle wall having a ventilating opening,

of the conveyor-type, each of'which ovens includes side walls and arear wall, the latter having an unloading opening, and the oven including a partition extending between the side walls and spaced from the-rear wall above the planeof said unloading opening to set off within the oven a cooling zone through which, and past said open ing, a flight of the conveyor descends; said cooling system comprising: a cold air supply duct sup* ported on: the outer side of said rearwa-ll and being substantially coextensive in area with-"the cooling zone, said rear wall and" the duct having a series of passages through which the duct com mun'icates With'thecooling zone, means for sup plying cooling" air tosaid duct, refrigeration means for chilling said air, ducts supported-on the outer side'of the'side walls of the oven and extending downwardlylfromabout the top plane of the supply duct a distance belowr-the-bottom plane of the said supply duct'so 'as-to have parts disposed on' opposite 'sides of the. region of the unloading: opening, the sidewalls of. the: oven and :the ducts adjacent thereto having passages through which the said ducts communicate-with the cooling zone and said region, and fluidimpelling meanshaving an inlet in communication with the-,upperends of; the second mentioned ducts-for Withdrawing gases therefrom. I I 3. A cooling system {for vertical -industrial ovens of theconveyor type, each of which: ovens includes side walls and a rear wall, -the-latter having anunloading opening, and the oven in: eluding-a partition ,extending between the side walls and spaced from-the rear wall above-the plane Y of said unloading opening toset 01f, within the-oven a cooling zone through which, and-:past said opening-,aflight of the conveyor descends; said cooling system comprising a cold air supply duct supported on the outer side of said rear wall and being substantially coextensive in area with the cooling zone, said rear wall and the of air flowing through said passages, ducts supported on the outer side of the side walls of the oven and extending downwardly from about the top plane of the supply duct a distance below the bottom plane of the said supply duct so as to have parts disposed on opposite sides of the region of the unloading opening, the side walls of the oven and the ducts adjacent thereto having passages through which the said ducts communicate with the cooling zone and said region, and fluid impelling means having an inlet in communication with the upper ends of the second mentioned ducts for withdrawing gases therefrom.

4. A cooling system for vertical industrial ovens of the conveyor type, each of which ovens includes side walls and a rear wall, the latter having an unloading opening, and the oven-including a partition extending between the side walls and spaced from the rear wall above the plane of said unloading opening to set off within the oven a cooling zone through which, and past said opening, a flight of the conveyor descends; said cooling system comprising a cold air supply duct supported on the outer side of said rear wall and being substantially coextensive in area with the cooling zone, said rear wall and the duct having a series of passages through which the duct communicates? with thei-coolingzone; means .for

supplying cooling air to'isaidpdu'ct; ducts supported'on' the 'outerside. ofthe sidewalls ofthe oven and extending downwardly fromr about the top-plane of the supplyduct a distance below-the bottom plane ofthe said supply-duct'so as tohave parts-:edisposed on opposite sidesfof: the region of the unloading opening, the side walls of the oven and, the ducts adjacent thereto having passages through which-the said. ducts communicatet with the cooling zone and said region, fluid impelling, meansihavingl an inlet in communication with-the upper :ends of the second mentioned'ducts ,for' withdrawing gasestherefrom; a bafflez-wall spaced inwardly from that portion of the-:reariwall having the unloading opening-and beingrin :substantially .the-j-vertical plane of "the aforesaid; partition, said'bafile' wall having a ven tilating. opening, and an air impeller for creat ingiea' draftxof air through said 'opening.

- 53 11 -cooling system for: vertical industria ovens-oftheconveyoritype, each of whichovens includes side walls anda rear'wall, the latter havinglan unloading opening, and the oven ineluding a partitionextending between the side walls-and; 'spaced'from the rear wall above the plane :of said unloading opening :to set off within the ovenia cooling zone through which, and past said' 'op'eningia flight'of the conveyor descends; said, cooling'system comprising a'c'old air supply duct supported'on the outer side of said rear wall and being substantially coextensive in area w-ith the" cooling zone, 'said rear'wall and 'the duct having-a series of passagesthrough which the duct communicates with the cooling zone, means for supplying cooling air to' said-duct, regulable refrigeration means for chilling said airgduct's supported on the outer sideo'f the side walls ofthe oven and extending" downwardly from about-the top plane of the supply (mega 'distancer'below the zhottom -:.plane ofthe -sa1 thereto having :passages through which the; said ducts? communicate with the cooling :z'one: and said :re'gion,; fluid: impelling meansJhaVing anQ-im let in communicationrwith theupp'er, endsofithe second' mentioned ducts "for withdrawingggases therefrom; a bafileawall spaced: inwardlyljv from that portion of; the rearewallhaving' the unloade ingop-enin'g and being in substantially the vertical plane of the" aforesaid: partition, said bafiie walli having ventilatingopenings, and an air-impellergin operative relation to each ofisaidsopeningsx x; w v CARL F. MAYER;1,"'

V, r, BE E QE CITED 1 rrne'; following references are of record in the fileof thisfpatentt I Y I v UNITED STATES PATENTS;

Number Nanie Date 333,939 Foote [Jan.'5, 1886 1,446,947 Taliaferrol Fehl 27, 1923 1,496,651 Bentz June'3j 1 924 1,742,099 Robertson an. Dec. 31,1929 1,167,872 Fox i June 24, 1930 1,844,094 Kneass' f Feb." 9, 1932 1,934,904 Barnett et a1. Nov. 14," 1'933 2,009,356 Otis '61; all Q L July 3O, 1935 2,110,352 Baker 'M ar.8, 19 38 2,134,906 Byron Nov. 1, 1933 2, 17,452 Peck 'OctLB, 1940 $355,814 -Mayer Aug. 15,:1944 2 ,385,962 1 Barnett o ct. 2, 1945 2,422,105 Lehrer June 10,1947

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