WO1988000310A1

WO1988000310A1 - Self-supporting vertical pipe structure of ceramic material

Info

Publication number: WO1988000310A1
Application number: PCT/DK1987/000079
Authority: WO
Inventors: Bent Lauritz Christiansen
Original assignee: Hasle Klinker- Og Chamottestensfabrik A/S
Priority date: 1986-06-27
Filing date: 1987-06-23
Publication date: 1988-01-14
Also published as: DK309386D0; AU7690787A; DK155552B; DK155552C; DK309386A

Abstract

A self-supporting vertical pipe structure which is suspended by its upper end, for example a central discharge pipe of a cyclone, consisting of fireproof units engaging each other is characteristic in that the units (3-9) are I-shaped. This structure has a tensile strength which is three times that of the known structures and moreover there are numerous other advantages by the structure, among other things it is possible with two unit sizes to build up pipes of many different diameters.

Description

SELF-SUPPORTING VERTICAL PIPE STRUCTURE OF CERAMIC MATERIAL.

The invention relates to a self-supporting vertical pipe structure of ceramic material, which is suspended by its upper end, for example a central discharge pipe of a cyclone, consisting of fireproof units engaging each other and being thereby interlocked.

Such structure is known from for example our co- pending Danish patent application no. 2055/83. This structure is built up by units which seen in tangential direction may almost be called C-shaped and they are connected by turning every second unit in such a manner that the C-shape is laterally reversed so that they may thereby be hooked into each other. Due to its shape the C-shaped unit cannot be symmetrically loaded by the suspension thereof. Exposed to wide temperature variations it is not easily recognised which temperature expansions or contractions will occur. Under any circumstances there will be no symmetrical stresses.

It is the object of the present invention to provide an improved structure.

The pipe structure according to the invention is thus characteristic in that seen in radial direction the units are substantially I-shaped, i.e. consist of a vertical body flange, two horizontally protruding upper flanges and two horizontally protruding lower flanges. There is thereby provided a structure which has proved to have a tensile strength being more than three times greater than that of the known structure with the same thickness of material and the same material. It is assumed that this is among other things due to a quite symmetrical structure providing symmetrical distribution of stresses by the actual mechanical load as well as by temperature variations provided that these are evenly distributed over the surface. Moreover, pipes of various diametres are easily made by this structure. It is thus possible by having two types of units of differing widths, i.e. width in tangential direction, to build up pipes of practically all diametres ranging between the diametre corresponding to the smallest unit and the diametre corresponding to the largest unit, respectively. It would for example be possible to obtain an intermediate diametre by building up a pipe by alternately using the first and the second unit along the periphery. This pipe would then have the average diametre. The pipe structure may furthermore be characteristic in that on the upper side of the horizontally protruding lower flanges and on the lower side of the horizontally protruding upper flanges there are provided coupling parts in the form of projections and holes which by assembling are adapted to interlock. It is thereby possible to obtain a highly stable structure.

An embodiment of this structure is characteristic in that the projections are exclusively provided on the lower flange, that the height thereof is smaller than the depth of the matching holes, and that projections and holes have the shape of truncated cones with the same cone angle. By letting the holes turn downwards they are not filled with sand, dust, raw meal or dirt which could concentrate the stresses and thus become destructive. The same applies when the depth of the holes is greater than the height of the projections.

Another embodiment is characteristic in that the side faces of the I-shaped profile of a unit are radial faces, i.e. have a radius as generatrix apart from the places where projections and holes are situated. It is thereby possible to achieve a good fit and thus tightness between the units.

For providing good sealing along the upper edge and the lower edge of the units the structure may be characteristic in that the upper and the lower faces of the I-shaped profile of a unit, viewed substantially in tangential direction, are provided with a labyrinth seal in that the individual faces or edges of the labyrinth of the individual unit extend circularly around the pipe axis or rectilinearly, substantially tangentially.

A particularly advantageous embodiment of this structure is characteristic in that the labyrinth seal is formed by a horizontal centre face, an outer inclined face extending upwardly of the centre face, and an inner inclined face extending downwardly of the centre face and that by two adjoining units there is a clearance between the centre faces whereas the inclined faces abut on each other. When the sealing or the abutment has thus been established along the inclined faces, the structure may absorb expansions or contractions in the longitudinal direction of the pipe without spoiling the sealing and not least without creating sealings as a result thereof. This structure can already stand expansions or contractions in tangential direction without ring stresses arising thereby. The only thing happening is that the units slide on each other in the contact surfaces, i.e. by the lower side of the upper, horizontally protruding flanges and by the upper side of the lower horizontally protruding flanges in that the clearances between projections and holes allow for this.

Finally, the pipe structure may be characteristic in that the inclination of the inclined faces correspond to the inclination of the projections and the holes.

It is thereby possible by suitable dimensioning to obtain units which despite protruding parts such as projections and labyrinth edges may nevertheless be edged into each other one by one for interlocking engagement thus obtaining a closed pipe which may still stand heat expansions in all directions.

The invention will be further explained with reference to the drawing wherein.

Fig. 1 is a section of a course by the upper edge of a pipe structure according to the in¬ vention viewed from outside,

Fig. 2 a, b, c and d in double rectangular view a standard unit (A in Fig. 1), Fig. 3 a, b and c in double rectangular view a suspension unit (B in Fig. 1), and

Fig. 4 a, b, c and d in double rectangular view an upper unit (C in Fig. 1).

Fig. 1 shows a section of a course by the upper edge of a pipe structure consisting of I-shaped standard units 1-9. By the upper edge 10 there are provided specially designed suspension units 11, 12 and 13 provided with holes 14, 15 and 16 which may be engaged by not shown radially and inwardly protruding pegs or pins of metal, preferably steel, which then support the pipe structure. These pegs or pins may advantageously be vertically adjustable so as to provide an even distribution of the forces along the periphery. Between the suspension units 11, 12 and 13 there are arranged units 17, 18 and 19 being I-shaped like the standard units 1-9 but having other proportions. It should be noted, however, that the units may have different widths as will appear from the drawing of the units 18 and 19 and the units 4 and 7. By combining units of different widths it is possible by the present structure to build up pipes of different diametres.

In Figs. 2a, b, σ and d the individual parts have the same reference numerals in the individual figures. The same applies to Figs. 3, 4 and 5. Fig. 2b shows the standard unit seen from the inside of the pipe, Fig. 2d shows a side view of the standard unit and the remaining figures 2a and 2c show sectional views as indicated in Fig. 2b.

Fig. 2b clearly shows the I-shape where the body flange 20 forms the centre part. At the upper end there are two protruding horizontal flanges 21 and 22 and at the lower end two protruding flanges 23 and 24. On the upper side of these lower flanges 23 and 24 there are cast four conical projections 25, 26, 27 and 28 whereas on the underside of the upper flanges 21 and 22 there are cast corresponding conical holes or recesses 29, 30, 31 and 32. It is noted that neither the projections 25-28 nor the holes 29-32 are circular symmetrial. The unit has by its upper edge a kind of labyrinth seal consisting of a horizontal centre face 33, an outer inclined face 34 extending upwardly of the centre face 33 and an inner inclined face 35 extending downwardly of the centre face 33. Units are in the same manner by their lower edge designed with a horizontal center face 36, an outer inclined face 37 and an inner inclined face 38. In mounted position inclined edges will engage inclined edges whereas between adjoining centre faces there will be a clearance. This will allow the units to be relatively displaced in vertical direction without any stresses occurring. The inclination of the inclined faces corresponds to the inclination of the sides in the projections and the holes. It is thereby possible to edge the units into each other.

Fig. 3 shows a suspension unit consisting of a body flange 38, two vertically protruding lower flanges 39 and 40 provided with projections 41-44 in the same manner as the standard unit according to Fig. 2. The height of the horizontal flanges are merely greater than by the standard unit because the strength of the suspension unit is weakened by a hole 45 adapted for suspension by means of a peg. The higher horizontal flange of this unit thus means that the adjacent units get a longer body flange as will appear from Fig. 4 and from Fig. 1, see parts 18 and 19.

The invention is not limited to centre pipes in cyclones but is conceivable for use for all other self-supporting structures built up by loose units.

Claims

8PATENT CLAIMS

1. Self-supporting vertical pipe structure of ceramic material, which is suspended by its upper end, for example a central discharge pipe of a cyclone, consisting of fireproof units engaging each other and being thereby interlocked, characterised in that seen in radial direction the units are substantially I- shaped, i.e. consist of a vertical body flange, two horizontally protruding upper flanges and two horizontally protruding lower flanges.

2. Pipe structure according to claim 1, characterised in that on the upper side of the horizontally protruding lower flanges and on the lower side of the horizontally protruding upper flanges there are provided coupling parts in the form of projections and holes which by assembling are adapted to interlock.

3. Pipe structure according to claim 2, characterised in that the projections are exclusively provided on the lower flange, that the height thereof is smaller than the depth of the matching holes, and that projections and holes have the shape of truncated cones with the same cone angle.

4. Pipe structure according to claim 1, 2 or 3, characterised in that the side faces of the I-shaped profile of a unit are radial faces, i.e. have a radius as generatrix, apart from the places where projections and holes are situated.

5. Pipe structure according to claim 1, 2, 3 or 4, characterised in that the upper and the lower faces of the I-shaped profile of a unit, viewed substantially in tangential direction, are provided with a labyrinth seal in that the individual faces or edges of the labyrinth of the individual unit extend circularly around the pipe axis or rectilinearly, substantially tangentially.

6. Pipe structure according to claim 5, characterised in that the labyrinth seal is formed by a horizontal centre face (33, 36), an outer inclined face (34, 37) extending upwardly of the centre face, and an inner inclined face (35, 38) extending downwardly of the centre face and that by adjoining units there is a clearance between the centre faces whereas the inclined faces abut on each other.

7. Pipe structure according to claims 3 and 6, characterised in that the inclination of the inclined faces correspond to the inclination of the projections and the holes.

8. Pipe structure according to one or more of the preceeding claims, characterised in that the pipe comprises units of different width, i.e. different size in tangential direction.