US 3261596 A
Description (OCR text may contain errors)
July 19, 1966 E. w. BowMAN 3,261,596
ANNEALING AND DECORATING LEHRS Filed Nov. l2, 1963 INVENTOR.
United States Patent O 3,261,596 ANNEALING AND DECORATING LEHRS Edward W. Bowman, 279 Derrick Ave., Uniontown, Pa. Filed Nov. 12, 1963, Ser. No. 322,825 3 Claims. (Cl. 263-8) This invention relates to new and useful improvements in annealing 'and decorating lehrs for glassware and the like and it is among the objects thereof to provide a lehr structure in which the glassware travels continuously on an endless belt through a plurality of heating and cooling zones in which the temperatures are separately fand independently controlled and which zones automatically maiutain the proper temperature conditions once the controls of each zone have been set.
Heretofore, annealing lehrs employed the drift of the treating medium such 'as hot and cold air from one end of the lehr to the other in an attempt to obtain a desirable annealing curve. Because of the many variables in the temperature conditions throughout the length of the lehr, it was diicult to obtain temperature control throughout the different Zones of the lehr through which the ware passed from the heating to the cooling end. In a former Patent No. 3,010,710, granted November 28, 1961, I have disclosed a zonal lehr which is divided into separately controllable temperature Zones by means of adjustable partitions or gates, but which in part depends on drift control to conduct the treating medium from one Zone to the next adjacent zone. In accordance with the present invention, both the heating and cooling zones are independently controlled. The drift from zone to zone is controlled by exhausting and taking in the treating rnedium, either hot or cold air, in each zone so that the zones may be properly described as locked in or fully controlled within itself. Adjustable partitions between the zones are supplied only in the cooling section, the lehr being preferably divided into eight Zones, the front four of which are heated and the rear four are cooled. In addition to each zone being separately controlled, the control elements of the zones are adjustable so that each zone may be operated at diiferent rates for heating `and cooling the Ware passing therethrough.
The invention will become more `apparent from a consideration of the accompanying drawing constituting a part hereof in which like reference characters designate like parts and in which:
FIGURE 1 is `a vertical section, partially in elevation, taken longitudinally of the furnace;
FIGURE 2 a transverse section taken along the line 2-2 of FIGURE 1; and,
FIGURE 3 is a transverse section taken along the line 3-3 of FIGURE 1.
In the drawing, the numeral 1 designates buckstays having an eye or channel sections 2 extending thereacross for supporting the hearth 3 of the lehr which is of any suitable refractory material such as re brick. The lehr is divided into eight zones by brick walls 4 and the first three sections .are separated at the top at 5 by means of refractory brick or other material suitable for a bridge wall. Beginning with the fth Zone, doors or gates 6 are mounted to be movable vertically by means of motors 7 to adjust the gates to clear the ware passing on a conveyor belt designated by the numeral 8, this being an endless belt which passes aro-und guide pulleys 9, 10 and 11 to a drive drum 12 that is driven by a motor 13 through a transmission 14. A plurality of tension pulleys 15 and 16 are provided to maintain proper drive tension with the drive drum 12.
A radiant panel is provided in the roof of the rst lehr zone which is the rapid heating section, the panel being heated by the well-known Selas burners 21 conice nected to a manifold fuel line 22 and zone 1 is further heated by burners 23 beneath the conveyor belt 8. The conveyor belt is dragged over a sheet metal support 25 and ware loaded at the front end, which is rat the left hand side of the drawing, passes through the respective zones to the inspection table or discharge end 26. A door 27 is provided at the front of the lehr and an adjustable door 28 at the discharge end `of the lehr, the latter being provided with counterweights 29.
As shown in FIGURE 3, the roof of each zone is provided with a spaced sheet metal panel 30 leaving openings 31 that communicate with the chamber 32 of each zone and with a fan chamber 33 of each zone. Fans 34 are provided on suspended shafts 35 through the roof of the lehr, the shafts 35 being driven by motors 36. Also, each zone is provided with an exhaust stack 37, FIGURE l, having a damper 38 mounted therein. Thermo-couple 40 is provided in the heating zone 1 and thermo-couples 41, 42, 43, 45, 46 and 47 are provided on the conveyor support 25 throughout the remaining zones of the lehr.
A plurality of fans 50 in the cooling Zone 8 may be provided for rapid cooling and additional fans 50a may be provided in the roof of zone 8 for the same purpose.
The thermo-couples 40 through 47 are connected to limit switches in a control panel, not shown, which switches are connected to operating control motors not shown. Once the burner switches and the cooling zone switches are set to produce annealing or heating in accordance with a predetermined temperature curve, the operation of the lehr is automatically controlled through these limit switches and thermo-couples in a Well-known manner.
Each of the section fans 34, as viewed in FIGURE 3, are provided with louvered dampers 52 to regulate the volume of -air drawn into the zonal chamber by the fan 34 and as previously described, each exhaust stack 3'7 is provided with a damper 38 to regulate the rate of exhaust of the circulated medium. By controlling the lair drawn into the zone chamber and regulating the amount exhausted from each zone, each zone maintains its own temperature across the ware and throughout the zonal area without drift from zone to Zone. As shown in FIG- URE 1, in addition to the burners 23 in zone 1, there are burners 54 and 55 in zones 2 and 3 and a lesser number of burners 56 in Zone 4, there being no burner in the remaining four zones of the lehr.
By regulating the burners to obtain the rapid heating of the ware and the slow cooling through the critical zone, which is in the front zones of the lehr, .and by regulating the inlet dampers 52 and the exhaust dampers 38, any desired temperature conditions may be created in the lehr for either annealing glassware or tiring enameled ware. The motors 36 driving fans 34 are constant speed motors and the regulable louvers 52, FIGURE 3, are motorized to be controllable from without the lehr. All of these controls of course may be assembled on a common control panel. As shown in FIGURE 3, detlector plates 60 may be provided to deect the circulating air .against the bottom of the conveyor belt or support to prevent stratication of the air across the zonal charnber. Also, a center baie wall 61 may be provided to deect the products of combustion from burners 55, as shown in FIGURE 3.
Although one embodiment of the invention has been herein illustrated and described, it will be evident to those skilled in the art that various modications may be made in the details of construction without departing from the principles herein set forth.
1. In 1an industrial heating furnace having a tunnel type heating and cooling chamber and an endless conveyor extending the full length of said chamber at substantially the vertical lcenter thereof, the improvement comprising, means for dividing said tunnel chamber into a plurality of independently controllable heating zones at the front of the t-unnel chamber and cooling zones toward the rear of said chamber, said means consisting of longitudinal spaced walls below said conveyor, correspondingly spaced bridge Walls extending from the top of said tunnel, burners at the top in the front zone of the tunnel chamber, burners at the bottom in all of the heating zones of said tunnel chamber, the heating zones beyond the front zone and the cooling Zones having fan chambers in the top, fans in said fan chambers for circulating the hot gases and drawing in air to the heating zones .and drawing in and circulating cooling air in the cooling zones of said tunnel, exhaust stacks extending from the Zones through the tunnel top adjacent the fan chambers, dampers in said stacks to regulate the exhaust of the circulating medium, and louvers at the top of the fan chambers for regulating the volume of air drawn into the Zonal chambers by the fans whereby each zone is charged with the treating medium and vented independently of any other zones.
2. A furnace as set forth in claim 1 in which each zone is provided with temperature responsive means for controlling the temperature condition of each zone.
3. A furnace as set forth in claim 1 in which the zones 5 are separated by adjustable doors above the conveyor,
References Cited by the Examiner UNITED STATES PATENTS FREDERICK L. MATTESON, IR., Primary Examiner.
WILLIAM F. ODEA, CHARLES SUKALO, Examiners.
D. A. TAMBURRO, D. G. BLACKHURST,
- Assistant Examiners.