US1868856A - Heating device for leers - Google Patents

Description

HEATING DEVICE- FOR LEERS Original Filed Jan. 21,1929 3 Sheets-Sheet 1 o oooooom-u I I I v SYLVESTER d mm TM a m Original Filed Jan. 21, 1929 a Sheets-Sheet gwowntov damn aha-.4 July 26, 1932 PATENT mm:

JULIUS SYLVESTER, OF PENNSYLVANIA ABSIGNOR TO SIMPLEX.EN-.

GINEEBING comm, OF WASHINGTON,

DELAWARE PENNSYLVANIA, A CORPORATION OI I HEATING DEVICE FDR Original application filed January 21, 1829, SeriaI Ho. 333.8%. Divided. and this application flied January 4,1930, Serial Ko. i18,57?.

This invention relates to heatin devices for leers, and while primarily designed for m n improved heating means, preferably of electrical type, whereby the sides of the leer may be heated'by heating units separate from those which heat the center of the leer,

. and also to provide separate heating devices above and, below the conveying mechanism,

whereby uniform heating of the material under treatment may be secured.

A further object of the invention is to provide means for protecting the heaters below 2!) the conveying mechanism from injury or short circuiting by falling particles of broken glass or other material under treatment, and for guiding such broken particles away from the heaters and conducting them to cleanout passages .for removal through doors at the sides of the leer.

A' still further object of the invention is to provide a leer having zones of varying temperatures, and insulations for said Zones to differing in degreeof heat conductivity for its articular zone.

he invention consists of the features of construction, combination and arrangement of parts, hereinafter fully described and claimed,'reerence being bad to the accompanying drawings, in which Fig. 1 is a diagrammatic side elevation of a sheet glass annealing roller leer to which.

' my improved heating means is shown ap- 40 plied, and a sheet forming apparatus coacting with the roller conveyor of the leer for intermittently forming glass sheets and feeding the same through the leer for annealing treatment.

M Fig. 2 is a vertical longitudinal section through the leer, showing highly heated and less highly heated or relatively cooling sections of the leer.

Fig. 3 is a vertical transverse section. on line 3-3 of Fig. 2.

In the illustrated embodiment of my invention as herein disclosed, I have shown the.

invention embodied in a leer chamber, kiln or tunnel 1 for annealing sheet glass, through which kiln the glass sheets intermittently formed by a casting apparatus 2 is transported by a roller conveyor 8, driven by any preferred type of driving apparatus. The rolls 3 of the conveyor are arranged suficiently close together to properly support the lass sheets, and the rolls located outside the iln are journaled in a suitable support ing frame while those located inside the kiln.

are journaled in the side wallsof the kiln, as shown particularly in Fig. 3. The rolls themselves may be of any suitable construction for the purpose, but 1 preferably employ the types of rolls disclosed in my aforesaid application Serial No. 333,887. The kiln is provided at its iniet end, at least, with suitable doors adapted be opened as required to ermit the sheets to pass into the kiln and t en closed to prevent loss of heat from the kiln when glass is not being 'annealed or no new sheets are being supplied.

Any suitable construction of doors for this purpose may be employed. The kiln, as illustrated in Fig. 1, is made up of two principal divisions which may be referred to as the highly heated portion 19 and the less highly heated portion 20. Each of these por tions is made up of a lurality ofsections. The characteristics of t ehighly heated portion are the more expensive construction designed to prevent heat radiation and the closer spacing of the heating units as indi-' cated in Fig. 2,. which figure shows the two adjacent sections of the highly heated and cooling portions ofthe kiln'at their point of.

intersection. The temperature Within the throu h the kiln at a proper speed for the annea ing action, the sheets being heated to annealing temperature in the highly heated portion of the kiln and then passing tothe cooling portion of the kiln, where their temrature is reduced, and the sheets finally ischarging at the end of the kiln upon a discharge conveyor from which they may be removed by suitable lifting means.

The means for heating the kiln comprises electric heating units arranged in two groups, 23 and 24, one above and the other below the conveyor rolls. Thus both the top and bottom of the glass passing over the rolls will receive heat. The lower group of heating units is preferably protected from damage and short circuiting by means of casings enclosing them, which casings include hoods or covers 25 which prevent broken glass or other material being conveyed by the rolls from falling upon the heating coils. The units 24 are closely spaced in the highly heated sec,

tion of the kiln, and are placed farther apart in the cooling section. Suitable control mechanism, not shown, is provided for regulating the amount of current supplied to the individual units along the length of the kiln in order to ensure the proper supply of current to each heater and the proper lowering of temperature from the entrance end to the discharge end of the kiln. The highly heated portion of the kiln is provided with solid masonry 26 designed to prevent loss of heat, while the cooling section of the kiln has a comparativel thin floor 27, supported on a framework 2;.

Preferably the units of the lower group of heating coils are arranged in three sections 28 29 and 30, arranged, respectively, at one si e of the center, at the center, and at the opposite side of the center of the kiln, so that an effective arrangement of heating units is provided allowing them to be individually controlled. This arrangement, clearly shown in Fig. 3, ermits the sides of the kiln to receive as hlgh a degree of heat as the center.

This ensures evenness of glass annealing and prevents deformation of the rolls. The heaters 23 above the rolls ma be arranged solely between the center and t 1e sides 0 the kiln, the center space being devoid of a heater, as the risin heat, by the described arrangement of the coils, will provide for a uniform heatin of the glass or other material above and be ow the line of the conveyor.

Beneath the rolls 3 are transverse cleanout passa es 31, 32, which slope from the center 0 the kiln downwardly and outwardly to openings at opposite sides of the kiln,

I closed by removable doors 34. This permits ly while in transit. The hoods or covers 25 are provided with sloping sides, as clearly shown in Fig. 2, and the heaters and their hoods are so arranged with respect to the cleanout passages as to adapt said sloping sides of the hoods to deflect the falling particles-downward into the cleanout passages 31, 32, from which they may be readily removed at required intervals.

As shown particularly in Figs. 2 and 3, the passages 31 and 32 are-arranged below and in a vertical plane between each pair of transverse heater groups 28, 29 and 30, so as to directly receive the broken glass sliding off the relatively inner sloping sides of the hoods 25 of the heaters of that pair of groups, and said passages 31 and 32 are provided with sloping sides which extend outward and upward laterally beneath the heaters of such pair of groups and intersect the sloping sides of adjacent pairs of channels which lie on opposite sides of the first-named channels and in alinement with the spaces between adjacent pairs of heater groups, the arrangement being such that the intersecting sides of adjacent sets of channels lie in a vertical plane between such adjacent sets of heaters of adjacent pairs,whereby the broken glass particles passing over the relatively inner faces of the hoods of a pair of heaters fall directly intotheintervening channels below, while the particles of glass passing over the relatively outer faces of the hoods of a pair of heaters and the relatively outer faces of the hoods of the next adjacent pair or pairs of heaters fall be tween the heaters of adjacent pairs and down upon the intersecting sides of adjacent sets of channels and are guided thereby into such channels. By this means the necessity of employing channels on opposite sides of each groupof heaters and between the same and each gron of heaters at opposite sides thereof is avoi ed, the cost of kiln construction reduced, and greater simplicity of construction and efliciency of operation obtained.

From the foregoing description, it will be seen that my invention provides a simple, reliable and eflicient type of heating and insulating means whereby the advantages set forth. are gained. forth particularly for use in connection with glass annealing kilns, it will, of course, be understood that it may be employed in conjunction with kilns for action upon other materials and for drying and many other purposes.

Having thus fully described my invention, I claim i 1. A leer having a heating chamber, a wa-re conveyor therein comprising transversely arranged longitudinally spaced rolls disposed \Vhile the invention is set between the top and bottom of the chamber, heating means at the top of the chamber and above the rolls comprising lon 'tudinally spaced pairs of unitary'electrical eaters, the Y heaters of each pair bein jointly controlled and extending transverse y of the leer chamber at opposite sides thereof and spaced from the center of the chamber, and heatin means at the bottom of the chamber and be ow the conveyor comprising longitudinally spaced groups of unitary electrical heaters, each group consisting of three independently controlled heaters extending transversel of the leer chamber and arranged respective y at the center of the leer, between the center and one side of the leer, and between the center i and the other side of the leer, whereby the sides of the leer at the top will be directly heated to substantiall the same degree and the center and sides 0 the leer at the bottom ma be controllabl heated to the same or varia le degrees, while the center of the chamber at the top will be heated by rising currents of heat from below.

2. A leer having a heating chamber, an openwork conveyor therein disposed between the top and bottom of the chamber, heating means at the top of the chamber and above the conveyor V comprising longitudinally spaced pairs of unitary electrical-heaters, the

heaters of each air extending transversely of the leer cham er at opposite sides thereof and spaced from the center of the chamber, and heating means at the bottom of the cham- 95 her and below the conveyor comprising longitudinally spaced groups of unita electrical heaters, each group consisting 0 three independently controlled heaters extending transversely of the leer v chamber and arranged respectively at the centerof the leer, between the center and one side of the leer, and between the center the leer,

3. A leer havin a heating chamber, a roll conveyor for con ucting ware therethrough, a plurality of pairs of Ion 'tudinallyspaced groups 0 heaters dispose at the bottom of said chamber, the heaters of each group extending transversely of the chamber, doors at the sides of the chamber, cleanout passages bein formed in the base of the chamber and in a inement with the spaces between the groups of heaters of each pair and slopin in opposite directions downwardl towa 55 the doors atthe opposite sides of the In, each channel having its side walls inclining upwardly .and outwardly beneath the related pair of heater on s and intersectin the adjacent side wa ls o the channels associated with other heater'groups at opposite sides thereof at points below and between the heater groups of adjacent pairs, and protective hoods overlying the groups of heaters and having inner and outer sloping sides, the relv atively inner sloping sides of e hoods of the and the other side of a In testimony whereof I afiix my sisgnature. T

JULIUS SYLVE ER.

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