Lining applied to the interior walls of ovens

Abstract: This invention concerns a tool for lining the layer of ceramic insulation applied to the interior walls of ovens consisting of a series of cell-like plates made of refractory material abutting securely against the ceramic layer by means of fixing mechanisms also realised in refractory material.

Description: This patent application involves a lining applied to the interior walls of ovens. Conventional ovens have a composite structure consisting, from exterior to interior, of a metal support casing, a layer of refractory material and an insulation layer that is generally in ceramic. A way to fix a ceramic insulation layer in the support casing of an oven is illustrated in the French patent FR-A-2 375 476. The use of ceramic insulation material on the interior walls of the oven is particularly critical in that the fumes strike the ceramic at very high temperatures causing the ceramic to flake, so that fine particles of material peel off the surface and are carried by the fumes outdoors where they pollute the atmosphere. In view of these considerations and the specific anti-pollution laws introduced, the possibility of lining the interior of the insulation layer of the oven with insulating panels in refractory material has for some time been considered. Recently ovens with a framework of refractory profile sections fixed securely to the support casing of the oven in which the refractory lining panels are fitted and fixed, have appeared on the market. This creates a sandwich type structure against the interior walls of the oven in the sense that the layer of ceramic insulation is between two layers of refractory material: the first conventional layer being on the exterior of the oven, the second lining and protection layer on the interior. The problem of lining the ceramic insulation layer of pre modification models, namely those that do not have the specific support framework for the refractory panels fitted during assembly, remains as yet unsolved. The scope of this invention is to permit lining, with refractory material, the interior ceramic layer of pre modification ovens without the specific support framework in refractory material. The lining according to the invention as defined in claims 1 and 2 comprises cell-like plates in refractory material and screws or pins also realised in refractory material for securely fixing said refractory plates against the internal face of the ceramic insulation layer on the side walls and top of the oven. In a preferred embodiment of the invention the refractory cell-like plates are fixed on the ceramic insulation layer mounted on the vertical walls of the oven by means of screws, also realised in refractory material. These screws are fitted into a specially designed hole at the centre of the respective refractory cell-like plates and then screwed to the layer of ceramic insulation. In particular, when the self-threading screws are screwed in, the shank of the screw progressively penetrates the layer of ceramic insulation thereby remaining securely fixed in the same; the large head of these screws obviously securely holds the respective refractory cell-like plate on the ceramic layer. The use of these self-threading screws is retained to be sufficiently secure for the application of the refractory plates on the vertical walls of the oven considering that in this situation each screw does not support the entire weight of the respective refractory plate, but simply ensures the secure vertical adhesion to the ceramic layer. In the case of refractory plates applied to the top of the oven, the screws support its relevant weight entirely so that in this case it is preferable not to use self-threading screws but bolts in refractory material and respective nuts. In this case, the length of the bolts must be sufficient to pass through the ceramic layer as well as the conventional refractory lining on the exterior of said ceramic layer - both pre-drilled - so that the relevant nut may be fitted on the respective shank, namely at the space between the exterior refractory layer and the support casing of the oven. A second construction version involves cell-like refractory plates fixed against the ceramic layer by means of special refractory pins, that are fitted in pre drilled holes on the ceramic layer itself as well as on the most conventional exterior refractory layer. Each of the pins is characterised by a wide circular head and a smooth shank terminating with a short hooking eyelet for a fork terminating at the top with a threaded shank screwed to a plate having a central threaded hole positioned - in the same way as for the nuts of the previous fixing technique described - between the support casing of the oven and the refractory layer on the exterior face of the ceramic insulation layer. For major clarity the description of the invention continues with reference to the enclosed drawings intended for purposes of illustration and not in a limiting sense, whereby: figure 1 is a view of a vertical section drawing of a wall of the oven on which cell-like plates according to the invention are fitted by means of self-threading screws; figure 2 is a vertical section drawing of the top of an oven to which the cell-like plates according to the invention are applied by means of bolts and respective nuts; figure 3 shows a vertical section drawing of the top of an oven to which the cell-like plates according to the invention are fitted by means of smooth shanked pin. With reference to figure 1, the structure of the side wall of an oven generally has a metal support casing (1) - in the case in question, consisting of series of metal vertical profile sections - on the exterior of this casing; the casing (1) having a layer of panels in refractory material (2) as well as a series of blocks (3) made of insulating ceramic material fixed to the support casing (1) by means of suitable hooks (4). The cell-like plates (5) made of refractory material according to the invention being fixed on the interior face of said ceramic blocks (3). More precisely, said plates (5) have a central hole in which a self-threading screw (6) made of refractory material is fitted and having a wide polygonal head (6a) whose threaded shank is screwed and fixed into the body of the ceramic block (3) immediately behind the respective refractory cell-like plate (5). Figure 2 refers to a section of an oven top; said top also consists of the conventional support casing, which in the case in question, consists of metal studs (7a) and panels (7b). A layer of refractory panels (2) is also fixed on this section of casing (7) as well as a series of ceramic insulating blocks (3) fixed to the support casing (7) by means of corresponding hooks (4). The cell-like refractory plates (5) according to the invention abut against the interior face of said ceramic blocks (3). In this case, said plates (5) are fixed by means of refractory wide-headed bolts (8) fitted into corresponding vertical-axis holes in the ceramic blocks (3) and the refractory panels (2) furthermost from these. The threaded end of said bolts (8) is screwed to respective nuts (9) positioned behind the above refractory panelling (2). Figure 3 is similar to figure 2 with the difference that in this case each of the cell-like plates (5) is fixed to the interior face of the ceramic insulation block (3) behind the same by means of a smooth-shanked refractory pin (10) with wide circular head (10a) also fitted into a corresponding vertical-axis hole in the ceramic insulation layer and the furthermost refractory layer (2). In particular, each pin (10) features an attachment eyelet (10b) at the end of its shank for a fork (10c) terminating at the top with a threaded shank (10d) that screws to a polygonal plate (11) having a central threaded hole positioned behind the above refractory panelling (2). It should be noted that even if figure 3 refers to the use of pins (10) for fixing the cell-like plates (5) to the top of an oven, said pins (10) are used in a similar way to fix the above cell-like plates (5) on the side walls of the oven.

Claims: A lining for the internal walls of an oven, said lining comprising cell-like plates of refractory material (5), a ceramic insulation layer (3), external refractory panels (2) and fixing means, wherein the cell-like plates (5) in refractory material are fixed against the internal side of the ceramic insulation layer (3) by means of said fixing means cooperating with a central hole provided in each plate; it being provided that the fixing means used to fix each cell-like plate (5) against the ceramic layer (3) mounted on the vertical walls of the oven is either (i) a self-threading screw (6) of refractory material with wide head (6a), whose shank is inserted into the central hole of the respective plate (5) until the wide head (6a) touches the external side of the plate (5) and is screwed to the ceramic layer (3) or (ii)a pin (10)in refractory material with wide head (10a), whose smooth shank ends with an attachment eyelet (lOb), a fork (lOc) attached to said eyelet and terminating at the top with a threaded shank (10d); it being provided that the pin (10) is fitted into the central hole of the corresponding cell-like plate (5) and through a through vertical-axis hole suitably drilled on the ceramic layer (3) and on the external refractory panels (2), so that the threaded shank (10d) is screwed with the threaded hole in the center of a polygonal plate (11) suitably positioned behind the refractory external panels (2); it being also provided that the fixing means used to fix each cell-like plate (5) against the ceramic layer (3) mounted on the top of the oven consists in a bolt (8) of refractory material with wide head, completely inserted into the central hole of the plate (5) and through a through vertical-axis hole suitably drilled on the ceramic layer (3) and on the external refractory panels (2), so that it is fitted to the central threaded hole of a nut (9) suitably positioned behind the external refractory panels (2). A lining for the internal walls of an oven, said lining comprising cell-like plates of refractory material (5), a ceramic insulation layer (3), external refractory panels (2) and fixing means, wherein the cell-like plates (5) in refractory material are fixed against the internal side of the ceramic insulation layer (3) by means of said fixing means cooperating with a central hole provided in each plate; it being provided that the fixing means used to fix each cell-like plate (5) against the ceramic layer (3) mounted on the vertical walls of the oven is either (i) a self-threading screw (6) of refractory material with wide head (6a), whose shank is inserted into the central hole of the respective plate (5) until the wide head (6a) touches the external side of the plate (5) and is screwed to the ceramic layer (3) or (ii)a pin (10) in refractory material with wide head (10a), whose smooth shank ends with an attachment eyelet (10b), a fork (lOc) attached to said eyelet and terminating at the top with a threaded shank (lOd); it being provided that the pin (10) is fitted into the central hole of the corresponding cell-like plate (5) and through a through vertical-axis hole suitably drilled on the ceramic layer (3) and on the external refractory panels (2), so that the threaded shank (lOd) is screwed with the threaded hole in the center of a polygonal plate (11) suitably positioned behind the refractory external panels (2); it being also provided that the fixing means used to fix each cell-like plate (5) against the ceramic layer (3) mounted on the top of the oven is a pin (10) in refractory material with wide head (10a), whose smooth shank ends with an attachment eyelet (10b), a fork (lOc) attached to said eyelet and terminating at the top with a threaded shank (10d); it being provided that the pin (10) is fitted into the central hole of the corresponding cell-like plate (5) and through a through vertical-axis hole suitably drilled on the ceramic layer (3) and on the external refractory panels (2), so that the threaded shank (10d) is screwed with the threaded hole in the center of a polygonal plate (11) suitably positioned behind the refractory external panels (2).

Inventors: FICOLA CARLO, FICOLA, CARLO
Applicants: FLII FICOLA DI SCIPIONE S R L, FRATELLI FICOLA DI SCIPIONE - S.R.L.
Application year: 1995
Main classification: F27D1
IPC codes: F27D1