DE2954310C2 - Process for the production of extruded hollow bricks from clay as well as plant and extrusion press for carrying out the process - Google Patents

Description

The invention relates to a method of manufacture of extruded hollow clay bricks, which run perpendicular to the direction of heat transfer Rows of large chambers, which are arranged offset from continuous longitudinal webs and from row to row Cross webs are limited, and have open-edged partial chambers in inner rows due to offset in which a horizontal clay strand is produced, in which the longitudinal webs extend vertically, and the clay strand is cut vertically into individual bricks, which are then dried and fired. From US-PS 21 92 723 a method of the type mentioned is known at ci ^ rn for extrusion of refractory bricks with two or three extremely long chambers, on the one hand, those in the raw mass trapped air is removed prior to extrusion, thereby increasing its density, and on the other hand the addition of pulverized coal brings about a lubrication of the mouthpiece, whereby smoother outer surfaces are achieved and the formation of cracks is to be prevented. At the next The burning process incinerates the enclosed coal and thus increases the porosity of the burned masses again. Customary brick clays that have not been specially pretreated can be used in the known process cannot be used because of the risk of cracking in the brick blanks. With the horizontal Extrusion presses are created when using conventional brick clays due to the unavoidable fluctuations frictional stresses between the exit speed and the conveyor speed, which are caused by the thin longitudinal and transverse webs of the brick to be produced cannot be compensated for. That's why especially in the lower corner areas of the clay strand emerging on the support surface of the conveyor base at least to deformations of the longitudinal webs, but in general to their complete breakage, with which of course the lattice structure is destroyed and the bricks become unusable,

The invention has for its object to provide a method of the type mentioned above, which Processing of common brick clays without special

Mixtures permitted under normal processing conditions.

A first solution to this problem results from the fact that the tone strand with a on its underside over the width of the clay strand continuous edge crossbar pressed and through a front of the mouthpiece horizontal cutting wire along the edge crossbar into a brick strand and a lower one Support strand is cut, with chambers being cut open in inner rows so that both strands are cut together vertically and that the goat blanks at least until a sufficient level is established Intrinsic strength remain on the sections of the support string that are used as transport documents, which are then removed.

An attachment to carry out this first procedure with an extruder, a conveyor system connected to the extruder, a drying system and a kiln is characterized in that the lower part of the chamber on both sides of the strand two outermost herons, forming nuclei to the lower Boundary line of the mouthpiece have a greater distance than the sub-chamber cores of the inner rows and that following the mouthpiece with one of the thickness of the edge transverse web to the sub-chambers the inner row corresponding to the distance to the conveyor system, a cutting wire transversely to the strand movement direction is excited

So a strand of clay emerges from the mouthpiece, which has a continuous lower edge crosspiece This has a greater thickness in the two outer edge areas, since it is also the after Cut there remaining cross bar contains the horizontal cut after exiting the mouthpiece is carried out at a distance from the support surface, which corresponds to the thickness of the edge crossbar at the corresponds to opening sub-chambers.

A second solution to the problem is obtained in that at the same time as the brick strand forming Clay strand a lower support strand is produced from clay, the clay mass through a continuous horizontal web of the mouthpiece is divided so that the support cord immediately after exiting the mouthpiece by the thickness of the horizontal web of the mouthpiece is increased that both strands together vertically are cut and that the goat blanks at least until sufficient intrinsic strength has been achieved on the sections serving as a tra.isport underlay of the support strand remain, which are then removed.

In this version, a thin band is pressed as the lower supporting strand, while the upper brick strand corresponds in its contours to the later brick. The support cord can easily be on a relatively short distance parallel to the top, since it is not an end product and therefore a minor damage that occurs is irrelevant.

This procedure enables the. Support cord with to provide additional guides for the brick strand. For example, it is conceivable to use the support cord in the Cross-section roughly U-shaped or like a comb and wider than the brick strand to be pressed, so that after the two strands are brought together, the protruding ones on the outside The bars grip the brick strand at the sides. The middle webs of the preferably designed support strand 'are arranged so that they protrude into the upwardly open partial chambers of the Ziegfcistrang.

To carry out this second method, an extrusion press is suitable, in which the mouthpiece is divided into two parts by a horizontal web, the part of the mouthpiece arranged below the horizontal web is wider than the upper part and is U-shaped or comb-shaped in cross-section and the two openings for the upstanding webs on the outside lie outside the vertical boundary surfaces of the upper part of the mouthpiece.
In both embodiments, a base of the same material is formed for the brick strand and the divided brick blanks, from which the brick blank is not removed during the further manufacturing process, in particular until the end of the drying process. The entire contact surface with the open sub-chambers and in particular the endangered corner areas are protected.Differences between the exit speed and the conveying speed have a particular effect on the support strand, in which, however, the formation of cracks and breaks is insignificant and the function of the previous edge crossbar eni.v _K richt For the first time, the theory of the optimal λ / heat flow extension can be applied to the edge area in extruded bricks made of clays processed in the usual way, so that the heat flow in the edge ions is continuously deflected in the same way via the longitudinal webs.

In the case of an arrangement of a sub-chamber in the outermost row as the lowest in the strand, manufacturing technology could even this subchamber to the bearing surface of the brick strand, i.e. to the joint surface of the brick be opened, but this would require very careful handling of the bricks when laying the wall. The loss of heat flow path in bricks in which the sub-chambers of the first and last row remain closed, but can be neglected.

The brick strand lying on the supporting strand serving as a transport base becomes vertical brick blanks cut up. The further process steps can now be carried out in three different ways will.

The first option provides for the goat blanks to be rotated by 90 ° after they have been separated, which means the chambers are brought into a vertical position, with the transport documents falling off at the same time. The brick blanks are then dried and fired in the usual way and the sections of the support strand can be returned in the raw mass.

The second preferred option provides that the brick blanks are not rotated, but on theirs Transport documents, the sections of the support string. remain and dry together with them will. This possibility has the additional advantage that more uniform drying can be achieved because the air can pass through the still horizontal air chambers freely and unhindered, thereby avoiding tensions due to different drying times of different areas of the blanks will. Then only the sections of the support string are removed and then the bricks burned. The dried Abb'äch'hitte can be fed back to the raw material, whereby no material loss occurs.

The third possibility is that the blanks on their transport support during the firing remain, which can be an advantage for blanks with particularly long large chambers.

te, where there is a risk of damage when removing the Transport documents related manipulation could exist.

The invention will now be described in more detail with reference to the figures of the drawings. Show it the

F i g. 1 and 2 plan views of two different exemplary embodiments of a brick to be produced, the

3 shows a vertical section through a clay strand after it emerges from a horizontal extruder, the

4 shows a schematic representation of a manufacturing plant, the

Fig. 5 and 6 sections through the mouthpieces of two horizontal extrusion according to the in F i g. 3 line V-V shown on the strand, the

F i g. 7 shows a vertical section through a clay strand similar to FIG. 3 according to another method example.

A first embodiment of a brick 20 which can be produced by the method according to the invention, as shown in FIG. 1 has an odd number η of rows 5 with air chambers perpendicular to the heat transfer direction A. Each row 5 of this embodiment consists of two rectangular, narrow, elongated large chambers 1, as well as a sub-chamber 2 ', the length of which corresponds to about half the length of the large chamber 1 the tile length = strand height extend in a straight line continuously, and separated by offset transverse webs 6. The first and last row 5 ', and thus also all others that fall on odd numbers in the sequence of the rows, begin in the drawing below with a sub-chamber 2'. As a result, a first transverse web 6 'belonging to the normal brick lattice is formed at half the height of the first large chamber 1 of the second row. The F i g. I (and also FIG. 2) also represents a view of the mouthpiece of the extrusion press. After the execution of FIG. 1, the brick 20 has two large chambers 1 and a sub-chamber 2 '(or 2) per row, which enables a particularly large large chamber length of 107.5 mm for an example brick line = strand height of 300 mm.

The brick 20 of FIG. 2 is with only large chambers 1 having basic rows 5 as well as staggered rows 5 ″. The basic rows 5 have two sub-chambers 2.2 'at the two ends of the row. With a brick length of 300 mm, for example the large chambers 1 have a length of 90 mm.

In both execution examples there are exceptions of the sub-chambers 2 'and 2 in the two outermost rows 5' all other sub-chambers to the abutting surfaces 3 open and therefore designated with 2 "

The known design of the brick with open sub-chambers 2 "offers the particular advantage that the values of a high thermal resistance that are valid for a central area of the brick with offset transverse webs apply to the entire brick, as the heat flow path is interrupted due to the Edge crossbar almost (Fig. 2) or completely (Fig. 1 above) that in the middle of the brick corresponds to the total thermal conductivity of the brick therefore actually reaches the value that was calculated for the center of the brick.

In the F i g. 3 to 5 a first method for producing a brick according to FIGS. 1 or 2 is shown The F i g. 3 shows a vertical section through a strand of clay emerging from a mouthpiece 9

13. This is provided on its underside with an edge transverse web 12, which, however, is cut off in the further process steps along level 2 and finally removed. For this purpose, the in F i g. 4 schematically illustrated manufacturing plant are used. In the vicinity of the mouthpiece 9 of the extruder 10, a cutting wire 11 is stretched transversely to the strand movement direction B at a distance corresponding to the width of the edge transverse web 12 to be cut off from the conveyor system 25, which is aligned with the horizontal boundary line b of the mouthpiece 9, which the emerging clay strand 13 into the upper brick strand 8 and the lower support strand 7 is cut.

The two strands 7, 8 are now conveyed further, with the support strand 7 serving as a transport base for the brick strand to protect it from damage, and by a vertically moving cutting device 22 which also moves in direction B during the cut , divided together, whereby the brick blanks 8 'and the sections 7 of the support strand 7 arise.

Following the vertical section, when the brick blanks 8 'are rotated 90 ° so that the air chambers extend vertically, the sections T can be removed. Preferably, however, it is provided that the brick blanks 8 'together with their transport documents, the sections T of the support strand 7, are brought into the drying system 23 and dried. Particularly even drying is achieved, as the air can sweep unhindered through the horizontal chambers. After leaving the drying system 23 there is also the possibility of separating the brick blanks 8 ′ from the sections T (arrow 26) before they are brought into the kiln 24.

This separation is preferably carried out, as shown by the solid arrows, since the dried blanks S 'are already sufficiently firm to rest on the cut surface so that the protection provided by the transport pad is no longer required. The removed dried sections T can be fed back to the raw clay so that no material loss occurs.

In the case of brick blanks 8 ″ with particularly long large chambers 1, however, it is also possible during the firing the support on the transport documents now designated as sections 7 "is desirable or advantageous be. In this case, the further treatment of the dried pieces 8 ″, 7 ″ runs together accordingly the dashed arrows in FIG. 4. They are thus fired together in the kiln 24 and divided after the exit, which in turn produces bricks 20. The also burned sections 7 " can no longer be returned to the raw mass.

The F i g. 5 shows a section through the mouthpiece 9 of the extruder 10 from FIG. 4, the section corresponding to the section along the line VV of FIG. 3 is laid through the strand, as well as the adjoining area of the conveyor system 25. In the mouthpiece 9, the cores 21, which correspond to the chambers 1, 2, are arranged. The lowest core 21 'forms the lower sub-chamber 2' of the last row 5 'and is at a distance of twice the width of a transverse web 6 from the lower delimitation line b of the mouthpiece 9. In the vicinity of the mouthpiece 9 is transverse to

Strand movement direction B of the cutting wire 11 in the middle of the distance between the boundary line b, which is aligned with the surface of the conveyor system 25, and the underside of the core 21 'stretched. The emerging clay strand is cut horizontally by the cutting wire 11 along the plane a, so that the support strand 7 and the brick strand 8 are formed. As apparent from the Ze ^ ssinung seen remains after cutting in Bereicn the core 2V one crosspiece 6 ", the g the edge-Ifsteg for 'formed part chamber 2' through the core 21> {F i. 3). For the third to (n -2) th sub-chamber 2 ″, which is open in the finished brick to the abutment surface 3 according to the line a, the lowermost cores extend further down so that their lower edges are in extension of the plane a. Their distance from line b therefore only corresponds to the distance between the cutting wire 11 and the surface of the conveyor system 25. When the clay strand is cut, these Tcükammerr! 2 "cut open. The bottom cores 21 'for the large chambers 1, however, also only extend as far as the core 21' shown for the sub-chamber 2 'of the outermost row 5', so that the large chambers after the horizontal cut through an edge web 6" are locked. Otherwise, the design of the mouthpiece 9 and the distribution and dimensioning of the cores 21, 21 'correspond to the illustration in FIG. 1 and 2, from which the differences in the bottom core page can be clearly seen.

A variant of the method for producing a brick according to FIGS. 1 or 2 is based on FIG. 6th Besch .eben, which also have the cut like F i g. 5 accordingly the line V-V in FIG. 3 shows. In this variant, the mouthpiece 9 of the extruder 10 consists of an upper part 14 'and a lower part 14 "which are separated by a cutting element. This can also be a cutting wire. Instead of the cutting wire, however, a fixed horizontal bar is preferred 15 provided. The formation of a fixed horizontal web 15 is explained in more detail below additional benefit.

The arrangement of the cores 21 is similar to that in FIG. The endeavor of the brick strand 8, after emerging from the upper part 14 'of the mouthpiece 9 on the transport base, formed by the support strand 7 to sink, which may damage the Brick grid could lead, is counteracted by the fact that the support strand 7 immediately after the exit from the lower part 14 'of the mouthpiece 9 by the shape of the conveyor system 25 by the thickness of the Horizontal web 15 is raised. This can happen very quickly, since destruction of the support strand 7 is not to be feared and a minor damage would be insignificant. The brick strand 8 is therefore short after exiting the mouthpiece 9 without slack on the support strand 7. From this point in time the further process steps proceed in the same way as on the basis of FIG. 4 explained

As mentioned above, the design of the cutting element in the form of a horizontal web 15 offers a further advantage, which is illustrated in FIGS. 7 is explained. It is thereby possible to make the cross-section of the support strand 7 and thus of the transport base not only rectangular, as in the method according to FIG. 5, but also to design differently. The cross-section of the lower support strand according to FIG. 7 preferably formed like a comb. The support strand 7 also has a greater width than the brick strand 8, so that the two outermost webs 16 of the comb are outside the side walls of the brick strand 8 and encompass them in the lowest area. In this way, an additional lateral support is achieved for the production of particularly long sub-chambers 2 '. At the same time, central supports can also be formed in the form of central webs i! 7, which protrude slightly into the open part chambers 2 ″ . After the support strand 7 has been raised, further processing takes place as described with reference to FIG.

Again for very long large chambers 1 or long sub-chambers 2, it can be advantageous, especially to stabilize the outermost longitudinal webs 4, to also press a further auxiliary strand at the top, which is cut off by a second cutting wire 11, which is on the brick strand 8 or on the brick blanks 8 'remains and is only removed at a later point, in particular after drying. For this purpose, too, this auxiliary strand can again have the shape of a U in cross-section, but lie upside down on the brick strand 8 and thus additionally support the upper corner areas. This can especially for the production of bricks 20 according to Fi g. 1 have meaning, in which the upper part chambers 2 ″ of the second to (n -l) th row are open. Otherwise, the upper open sub-chambers 2 ″ are formed by corresponding shaping of the inner surface of the mouthpiece.

For this purpose 4 sheets of drawings

Claims (6)

Patent claims: 1. Process for the production of extruded hollow bricks from clay, which are perpendicular to the direction of heat transfer running rows of large chambers that of continuous longitudinal webs and from row to row staggered transverse webs are limited, and due to offset in inner rows have open-edged sub-chambers, in which a horizontal clay strand is generated in which the longitudinal webs extend vertically, and the tron strand is cut vertically into individual brick blanks is, which are then dried and fired, characterized in that the Clay strand with a transverse edge web on its underside across the width of the clay strand pressed and along by a horizontal cutting wire (il) placed in front of the mouthpiece (9) the R ».dquersteg is cut into a brick strand (8) and a lower support strand (9), wherein in inner rows (5 ") chambers (2") are cut so that both strands (7, 8) together be cut vertically and that the brick blanks (8 ') at least until a sufficient Intrinsic strength on the sections (7 ') of the support strand that are used as a transport base (7) remain, which are then removed. 2. System for carrying out the method also claim 1 with an extruder, a conveyor system connected to the extruder, a drying system and a kiln, characterized in that the lower sub-chamber (2 ') of the two outermost rows (5') on both sides of the strand forming cores (21 ') to the outer limiting knee (b) of the mouthpiece (9) have a greater distance than the sub-chamber cores of the inner rows (5 ") and that following the mouthpiece (9) with one of the thickness of the edge crossbar A cutting wire (11) is stretched transversely to the strand movement direction (B), corresponding to the distance from the conveyor system (25) corresponding to the part chambers (2 ") of the inner row. 3. Process for the production of extruded hollow clay bricks perpendicular to the direction of heat transfer running rows of large chambers, those of continuous longitudinal webs and transverse webs that are offset from row to row are limited, and have open-edged partial chambers in inner rows due to the offset, in which a horizontal clay strand is produced in which the longitudinal webs extend vertically, whereupon the clay strand is cut into individual bricks, which are then dried and fired, characterized in that at the same time as the clay strand forming the brick strand (8) a lower one Support strand (7) is produced from clay, the clay mass through a continuous horizontal web (15) of the mouthpiece (9) is divided so that the support strand (7) immediately after exiting with the mouthpiece (9) by the thickness of the horizontal : ges (15) of the mouthpiece (9) is raised that both strands are cut vertically together and that the brick blanks (8 ') at least up to Achievement of sufficient intrinsic strength on the sections serving as transport documents (7 ') of the support strand (7) remain, which are then removed. 4. The method according to claim 3, characterized in that the support strand (7) in cross section approximately Is U-shaped, and the lateral, vertical webs (16) during transport encompass the lateral edge longitudinal webs (4 ') of the brick strand (8). 5. The method according to claim, characterized in that that the support strand (7) is formed like a comb in cross section, and its aittlere, vertical webs (17) during transport into the downwardly open part chambers (2 ") of the brick strand (8) protrude. 6. extrusion press for performing the method according to claim 4 or 5, characterized in that that the mouthpiece (9) is divided in two by a horizontal web (15), that the one below the horizontal web (15) arranged part (12) of the mouthpiece (9) opposite the upper part (13) and widened is U-shaped or comb-shaped in cross-section and that the two openings for the protruding outside The webs lie outside the vertical boundary surfaces of the upper part (13) of the mouthpiece (9).