US3452408A

US3452408A - Continuous tunnel kilns having a rotary roller sole for firing ceramic materials

Info

Publication number: US3452408A
Application number: US603023A
Authority: US
Inventors: Adriano Bossetti
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-12-21
Filing date: 1966-12-19
Publication date: 1969-07-01
Anticipated expiration: 1986-07-01

Description

y 1, 1969 A. BOSSETTI 3,452,408

CONTINUOUS TUNNEL KILNS HAVING A ROTARY ROLLER SOLE FOR FIRING CERAMIC MATERIALS Filed Dec. 19, 1966 INVENTOR Ape/4N0 fiosssrr/ BY y-JW ATTORNEYS United States Patent .0

Int. Cl. 1 27b 9/00 U.S. Cl. 25-142 2 Claims ABSTRACT OF THE DISCLOSURE A continuous tunnel kiln has a sole comprised of rotating rollers for supporting ceramic workpieces during firing, the rollers being hollow for the reception of gas burners and multiperforate for the escape of combustion gases.

This invention relates to a continuous tunnel kiln for firing any ceramic materials having each sole of its tunnel (which has to be run through by the firing material) constituted by one or more adjacent tunnels provided with a set ,of rollers disposed transversely in respect to the tunnel, said rollers projecting from the kiln wall towards the outside, to cause, rotating all together, the advancing of the material carrying plates. Expedients and arrangements are provided to prevent material under firing from hindering the furnace operation should the plate carrying said material break, which can occur fairly easily, due to the high temperatures reached in these kilns.

The rollers provided for advancing the plate carrying thescharge are hollow, with circular section and have relatively thin walls, to facilitate their cooling. They are located transversely in adapted grooves of the upper layer, they are not adjacent but spaced apart and protrude slightly relative to the upper sole level of the tunnel. The distance between the rollers outside surface and that of the cavity is reduced to the minimum.

In addition, the sole according to this invention is formed of two separate superimposed layers, each of them being either continuous or formed by block elements; moreover, each layer is provided with transverse chambers, it being possible to arrange electrical heating means both within the chambers of the upper layer (that is, within the space between the rollers) and within the lower chambers, and possibly within both of them.

Furthermore, according to the present invention there is provided small gas burners arranged within said transverse chambers in lieu of the electrical heating means, the chambers preferably having suitable holes for exhausting the combustion products.

This invention further provides small gas burners arranged also or only within all or part of the rotary rollers, each roller within which a burner is located preferably having suitable holes for exhausting the combustion products.

The present invention will be further described, by way of example, with reference to the accompanying drawings in which:

FIG. 1 is an elevational view according to line 11 of FIGURE 2 showing a kiln for firing ceramic materials according to the present invention;

FIG. 2 shows a horizontal section taken along the line 2-2 of FIGURE 1, looking in the direction of the arrows; and

FIG. 3 is a detail of FIGURE 1, showing in perspective view the structure of the cavities of the upper layer, each cavity being adapted to receive a gas burner.

3,452,408 Patented July 1, 1969 Each kiln tunnel has, as its sole, a layer 6 of refractory material provided with transverse chambers 2, suitable for receiving a gas burner for heating purposes; such a layer 6 shall (or may) constitute besides the bottom for the channel considered, also the ceiling for an underlying channel (not shown). The upper surface 3 of overlying layer 3 is shaped so as to define transverse grooves 4, in which the rollers 5 are mounted and rotate, as Well as transverse chambers 2'. The arrangement for one or more gas burners is provided within one or more of said chambers 2, which chambers are practically on the level of the roller axes and between one roller and the adjacent one.

Chambers 2 and 2' preferably have a plurality of holes 8 for the exhaust of combustion products.

The arrangement of small gas burners interconnected by a plurality of supply conduits is provided within all or some of rollers 5; preferably, each roller 5 has a plurality of holes 8 for the exhaust of combustion products, or other purposes hereinafter explained.

The gas burners are arranged within rollers 5 in addition to or in lieu of the above-cited burners provided within chambers 2 and 2'.

Rollers 5 may be cooled by air, which emerging from holes 8' also will serve as secondary air combustion for the burners arranged within said rollers and/or

chambers

2 and 2, as well as for causing the atmosphere within the kiln to become oxidative if such air is supplied in a suitable amount. In rollers 5, wherein the gas burners are arranged, there can also be effected a combustion with an excess of gas so as to provide a reducing atmosphere in the kiln, through the holes 8'.

The control for the rollers and the other details of construction of the kiln will not be herein described since they are already known by the persons skilled in the art.

It is apparent also that some modifications or changes shall be made by those skilled in the art to the above described embodiment, without departing from the protective limits of the present invention.

What is claimed is:

1. In a furnace for ceramic material, the furnace having a vault and a sole, the sole having a continuous bottom and a plurality oftransversely extending spacers extending across said bottom, said spacers defining transverse grooves between them, rollers mounted for rotation in and extending lengthwise of said transverse grooves and protruding a short distance above said spacers, said spacers having cavities for heating means therein extending lengthwise of said spacers and disposed between upper portions of said spacers and said continuous bottom; the improvement in which said rollers are hollow for the reception of gas burners therein, and said rollers have openings extending therethrough for the passage of combustion gases from the hollow interior of the rollers through said openings and into the furnace.

2. In a furnace for ceramic material, the furnace having a vault and a sole, the sole having a continuous bottom and a plurality of transversely extending spacers extending across said bottom, said spacers defining transverse grooves between them, rollers mounted for rotation in and extending lengthwise of said transverse grooves and protruding a short distance above said spacers, said spacers having cavities for heating means therein extending lengthwise of said spacers and disposed between upper portions of said spacers and said continuous bottom; the improvement in which said cavities contain gas burners and are in communication both with each other and with 3 4 the inside of the kiln through holes, to allow the passage References Cited of the fuel gases towards the inside of the kiln, said UNITED STATES PATENTS rollers being hollow for the reception of gas burners 3,110,075 11/1963 Bossatti 25 14Z therein, and said rollers having openings extending there- 3,135,037 5/1964 Bossatti through for the passage of combustion gases from the 5 3,262,17 7 196 B ni 25 14 hollow interior of the rollers through said openings and into the furnace WILLIAM J. STEPHENSON, Primary Exammer.