US1698479A

US1698479A - Apparatus for annealing sheet glass

Info

Publication number: US1698479A
Application number: US141631A
Authority: US
Inventors: Mulholland Vergil
Original assignee: Hartford Empire Co
Current assignee: Hartford Empire Co
Priority date: 1926-10-14
Filing date: 1926-10-14
Publication date: 1929-01-08
Anticipated expiration: 1946-01-08

Description

Jan. 8,1929. 1,698,479

V. MULHOLLAND APPARATUNS. FOR ANNEALING SHEET eLAss- Filed Oct. 14, 1926 i=1- v 4 1120612101" 6 il zzwuzhzmz {3%{5 y mm mm,

A iiofn 11y.

Patented Jan. 8, 1929.

Ll NlTED STATES PATENT OFFICE."

VERGIL MULHOLLAND, OF WEST HARTFORD, CONNECTICUT, ASSIGNOR TO HARTFORD- EMPIRE COMPANY, OF HARTFORD, CONNECTICUT, A. CORPORATION OF DELAWARE.

APPARATUS FOR ANNEALING- SHEET GLASS.

Application filed October 14, 1926. Serial No. 141,631.

This invention relates to apparatus for annealing sheet glass and it has particular relation to lehrs of the tunnel type, through which sheets; or continuous strips of glass are transported by a conveyor, and in which they are subjected to varying temperature environments, in order to relieve stresses and strains that may exist in the glass.

One of the objects of this invention is to provide a lehr in which both the upper and the lower surfaces of the sheet glass will be subjedtedto a uniform temperature at any given cross sectional portion of the tunnel, and in which the temperature above and be low the glass may be easily regulated throughout the entire length of the tunnel. Briefly, this temperature control is obtained by providing a tunnel lehr having two separate and independent fire boxes, one above and one beneath the receiving end of the tunnel, and communicating respect1vely with heating flues extending longitudinally above and beneath the tunnel. The temperature in each of these flues is regulated at will by damper-controlled openings through which air from the outer atmosphere maybe admitted into the flues in regulable quantities to dilute and cool the heated gases passing therethrough.

In the accompanying drawings:

Figure 1 is a diagrammatic longitudinal section through a tunnel lehr constructed in accordance with the invention;

Fig. 2 is a vertical transverse sectional view,

on a larger scale, taken on. line 22 of Fig. 1, and illustrating the method of connecting the flues-"to a common suction device;

Fig. 8 is a similar view taken on line 33 of Fig. 1 and illustrating the construction of the damper-controlled openings in the flues, and

Fig. 4 is a vertical longitudinal sectional view through a. portion of the tunnel and illustrating the baflie plates for minimizing the draft above the glass.

Referring to the drawings, a relatively wide and low lehr tunnel 1 is illustrated as being constructed of a plurality of substantially similar metallic sections 2 arranged in end-to-end relation. The tunnel sections are mounted on rollers 3 which ride on rails 4 carried by a plurality of pedestals 5. By

, neath the lehr and is supported by rollers 7 The conveyor 6 may be of any preferred construction and may be driven by any suitable mechanism indicated at 8, Fig. 1.

Heating flues

9 and 10, respectively, extend longitudinally above and beneath the tunnel and respectively communicate, through damper controlled

passageways

11 and 12,

with the boxes 13 and 14 disposed one above and one beneath the receiving end of the lehr. A plurality of damper-controlled openings or

stacks

15 and 16 are disposed at intervals longitudinally of the

flues

9 and 10, respectively, and establish communication between these flues and the outer atmosphere.

Heated gases from the fire boxes 13 and 14 are drawn through the

flues

9 and 10 by means of a common suctionv device 17, which communicates with the upper flue 9 through a damper-controlled passageway 18 and with the lower flue 10. through a damper-controlled passageway 19 and a pair of pipes 20 disposed one on each side of the tumiel. This suction device may be of any preferred construction but is herein shown as comprising a motor-driven suction fan. Heat is prevented from dissipating too rapidly from the flues and from the tunnel by means of a suitable casing 21 of insulating material.

By suitably adjusting the dampers in the

passageways

11, 12, 18 and 19, the draft in the

flues

9 and 10 may be regulated at will a tendency for a current of air to flow through the tunnel above the glass and to disturb the desired heat conditions therein. WVhile this difficulty may be partly compensated for by supplying more heat to the upper flues than to the lower, it may be found desirable 'to equip the tunnel with a pluralityof transversely extending baflie plates or partitions 22, Fig. 4, which depend from the top of the tunnel and are arranged at intervals therealong. These baflies are preferably cast integral with the top wall of the tunnel and extend downwardly to a point adjacent to the glass, suflicient clearance being provided to prevent them from contacting with the glass when they expand under the influence of heat.

The draft above the glass is thereby re- Y duced to that which may pass through the relatively small spaces between the upper surface of the glass and the lower edges of the baflies 22. The air in the spaces between the battles is in a substantially static condition and retains the temperature of the adjacent portions of the heating flue.

-- By means of the above-described construction, a uniform temperature may be readily of the invention as defined in the appended claims.

I claim as my invention 1. Apparatus for annealing sheet glass, comprising a tunnel, means for transporting sheet glass therethrough, a heating flue extending longitudinally above said tunnel and communicating with a fire box located above the receiving end thereof, a heatin flue extending longitudinally beneath said tunnel and communicating with a fire box located beneath the receiving end thereof, and means,

located at intervals longitudinally of each of said flues for controlling the temperatures in different zones of said tunnel.

2. Apparatus for annealing sheet glass, comprising a tunnel, means for transporting sheet glass therethrough, a heating flueextending longitudinally above said tunnel and communicating with a fire box located above the receiving end thereof, a heating flue ex--.

tending longitudinally beneath said tunnel and communicating with a fire box located beneath the receiving end thereof, and means located at intervals longitudinally of each of said flues for admitting atmospheric air into said flues to control the temperatures in diiferent z ones of said tunnel.

3. Apparatus for annealing sheet glass, comprising a tunnel, means for transporting sheet glass therethrough, a heating flue extending longitudinally above said tunnel and communicating with a fire box located above the receiving end thereof, a heating flue extending longitudinally beneath said tunnel and communicating with a fire box located beneath the receiving end thereof, and means located at intervals longitudinally of each of said flues for admitting atmospheric air in regulable quantities into said flues to control the temperatures in different zones of said tunnel.

4. Apparatus for annealing sheet glass, comprising a tunnel, means for transporting sheet glass therethrough, a heating flue ex-.

tending longitudinally above said tunnel and communicating with a fire box located above the receiving end thereof, a heating flue extending longitudinally beneath said tunnel and communicating with a fire box located beneath the receiving end thereof, a single suction device communicating with both of said flues for drawing heated gases from said fire box through said flues at subatmospheric pressure, and means located at intervals long'itudinally of each of said flues for controllingthetemperatures in diiferent zones of said tunnel.

.5. Apparatus for annealing sheet glass, comprising a metallic tunnel, means for transporting sheet glass therethrough, a flue extending longitudinally above said tunnel, the top wall of said tunnel constituting the bottom wall of said flue, a the box disposed above the receiving end of said tunnel and communicating with said upper flue, a heating flue extending longitudinally beneath said tunnel, the bottom of said tunnel constituting the upper wall of said lower flue,

a fire box located beneath the receiving end of said tunnel and communicating with said lower flue, means for causing the flow of heated gases through both ofsaid flues at subatmospheric pressure, and a series of dampercontrolled-openings disposed at intervals longitudinally of each of said flues for admitting regulable quantities of air from the outer atmosphere into said flues to dilute and cool the hot gases passing therethrough and to thus independently control the temperatures in diiierent zones longitudinally of said flues and tunnel,

6. Apparatus for annealing sheet glass comprising a tunnel, means for transporting sheet glass. therethrough, similar longitudicomprising a tunnel, means for transporting sheet glass therethrough, similar longitudinal heating fines respectively above and below said tunnel, similar fireboxes communicating respectively With said fines at points opposite one another, similar means for each flue spaced at intervals therealong for controlling the temperatures therein, whereby the heat conditions above and below the glass may be separately controlled, and means to lo Withdraw the heating media from said fines.

Signed at Hartford, Conn, this 13th day of October,

1926- VERGIL MULHOLLAND.