DE7819861U1 - Shaped ceramic product, especially chimney pipe - Google Patents

Description

DR. SOLF & ZAPF

Authorized representative at the European Patent Office
Professional Representatives before the European Patent Office

I / fr / 1012 G OTAVI MINEN AG, Hynspergstr. 24, 6000 Frankfurt / Main 18

/ Shaped ceramic product, especially chimney pipe "> I \ / j

The invention relates to a ceramic-fired molded ι Product, especially a chimney pipe for installation as an indoor f

pipe into a multi-shell assembly chimney. |

Such chimney pipes are mostly using Clay and chamotte Made in a ceramic fire. They are usually used in multi-layer house and heating chimneys that are fixed with and / or liquid and / or gaseous fuel-operated heating systems. A house chimney should therefore be sufficiently resistant to exposure to fire, smoke or exhaust gases as well as by sweeping devices (DIN 18160). So must The chimney pipe as a building block of the chimney is fire and acid-resistant, gas-tight and

be soot-free and especially a sufficient one Compressive strength and thermal shock resistance

point. In addition to the compressive strength is in connection with the requirement to maintain the gas tightness Resistance to temperature changes during operation is an important property that a chimney pipe must have. Because the heating systems act on a chimney and thus the chimney pipe neither continuously nor with smoke or exhaust gases at a constant temperature. Rather, the temperature influence can be very unstable and changeable.

A chimney pipe that does not relieve the structural stresses that occur during operation due to temperature fluctuations can compensate for tears. The formation of cracks usually affects the gas tightness and strength of the Chimney lost, which can lead to significant damage.

The object of the invention is. the tendency to form cracks in a ceramic-fired chimney pipe by increasing the resistance to temperature changes. ■

According to the invention, this object is achieved by a ceramic-fired chimney pipe, the shards of which have a texture, the texture being formed by pore chambers.

The term "texture" is borrowed from mineralogy. It is included in this subject area by external

Causes caused spatial arrangement of the mineral aggregates of a rock Understood. In the context of the present invention, the term texture is used to denote the structure of the fired Shards of the ceramic tube described.

The shard of the ceramic pipe according to the invention preferably has long, closed pore chambers in the cross-sectional image, the longitudinal axes of which are approximately parallel to the wall of the chimney pipe. According to a special feature of the invention, a grain, preferably a rock grain, is stored in a corner of the chamber, the rock grains in the respective chamber in the same corner of the chamber. In this respect, the texture results from the narrow, elongate, parallel to the wall prien oriented Porenkaiwnsrn with in each case corresponding asr same corner seated rock grains. It does not matter here that the assumed longitudinal axis of the pore chambers is perpendicular or parallel to the longitudinal axis of the Kaminronr. It is essential that the majority of the chambers are spatially directional.

The porosity of the body becomes through the pore chambers considerably larger. It can be increased up to three times the original body size. The water absorption of the Casino tube, on the other hand, is not increased to the appropriate extent, because they are mostly closed chambers and the

-A-

Karemern usually not with the outer shell pressed skin of the chimney pipe are in connection. In this respect, the gas tightness that the chimney pipe "inherently" has, not impaired. The porosity increases depending on the amount added and the grain size of the Aggregate. The bulk density of the body is determined by the porosity and the spec. Weight of the aggregate certainly.

Due to the textured porosity, which is oriented parallel to the wall in the form of pore chambers, the compressive strength - measured by loading in the longitudinal axis direction of the pipe - is not influenced in such a way that the pipe does not meet the requirements in this respect. It is essential, however, that through the textured chamber porosity significantly increases the resistance to temperature changes and, associated with it, the The tendency to crack can be reduced. This significant advance is illustrated by the following example shown.

example

Is compared. a conventional fireclay chimney pipe with a homogeneous structure of known structure and a Chimney pipe - of the same structure, but with the one according to the invention Pore chamber texture.

The determination of the thermal shock resistance is based on DIN 51068, sheet 1, the samples having a

C ^ AVI -MZΤνΞϋ * AG

-1..5

Diameter of 50 mm and a height of 25 mm (corresponding to
the wall thickness of the pipe).

The number of test runs that the sample has carried out is determined
withstands destruction according to DIJi 51068. From a test series by
Ten tests showed that e: m commercially available chimney pipe can withstand 3 to 5 and the test pipe according to the invention can withstand 15 to 35 test cycles.

The following porosities were measured: the commercially available Chimney pipes between 6.3 and 8.6% and in the case of the chimney pipes according to the invention between 13.2 and 18.6%.

To produce the textured chimney according to the invention

Rohres are clay with the usual Gemen.gteile such. B. I.

Chamotte and water mixed, the moist mixture to |

pressed into a pipe string, the pipe pipe in sections j

cut and the pipe sections burned to the chimney pipe, |

wherein the batch grains are added and the strand {pressing is performed such that the grains having a

tail-shaped pore chamber in connection. J

I The rock grains are made with grain sizes from 2 to

6 mm is used, which preferably has a hardness over 180 N / mm ² f according to Frechen and an abrasion resistance of less than 8 cm ³ /

OTAVI-KIKEK AG

50 cm (measured according to Böhme according to DIN 52108). Of course, it is also possible to use synthetically produced grains, among other things in the form of waste products such as using granulated slag. Natural minerals such as corundum can also be used. Basalt is preferably used as the rock grain. Good results are also obtained when hard-fired Fireclay grains are added. The additional amount and grain size depends on the desired increase in the Porosity. Rock grains are preferably added in amounts of 5 to 20% by weight, based on the mixture. The choice of the hardness of the grains, on the other hand, depends on the abrasive effect of the mass in which the grains are embedded. Because the grains should be as sharp as possible and not be destroyed during extrusion. Rather, it should be the crowd Sliding past the grain surface a cavity, namely the pore comb, without the grain is worn down. The chambers are built up by the pressing process, the rock grain after pressing in the Corner in which the pressing force has acted limits the chamber.

The manufacturing process can be controlled in such a way that either the rock grains in the extrusion the mass migrate or the mass flows past the rock grains and the rock grains are slowed down during pressing will. In any case, the mixing ratio of the mixture and its plasticity must be chosen in such a way that that starting from the aggregate during extrusion

can form a cavity that does not collapse again after pressing and does not expand in the event of a fire or shrinkage of the body.

Particularly well-textured cullet is obtained if a screw press is used for extrusion and the moisture content of the mixture is set _Λ between 10 and 20, preferably 12 % by weight . The moisture content of the cash register is chosen so that the pores created during pressing are not squeezed together again. It is also advantageous to apply superheated steam to the moist mixture before pressing and thereby to increase the temperature of the mass to 55 to 70 ^° C. The mass should have a malleability value according to Pfefferkorn of 1.2 to 1.5. It does not matter that the grains are still recognizable in the chamber after the fire. They can melt during the fire and cause glazing and thus solidification of the pore chamber, which can contribute to increasing the strength of the chimney pipe. Preferably, however, the grain should still sit in the corner of the chamber even after the fire, because this way the strength of the chimney pipe reaches an optimal value. This is because the grains apparently support the chamber walls in the event of pressure loads in such a way that the chambers do not represent any significant weakening of the structure of the fragments.

Preferably used mixture consisting of:

55-75 wt% slate clay
10-25 wt. SS chamotte of the grain size

0 to 4 am

5-20% by weight of texture granules (core 2-6 mm;

> 180 TJ / nnr · ² hardness) 10-20 wt. SS water

In particular, mixtures are used which have the following composition.

58-63 wt% slate clay
18-20 wt. SS chamotte
A- 6 wt. SS basalt grain (from 4 to 5 jam;

from 200 to 240 N / mm ² hardness) 3 - 5% by weight fireclay grain (from 3 to 4 mm?

from 180 to 200 N / mm ² Harxe) 12-14 % by weight of water

The invention is illustrated by way of example with the aid of the drawing explained. Show it:

Fig. 1 is a cross-sectional, approximately square

Extruded chimney pipe, Fig. 2 shows a section according to II in Fig, I.

The chimney pipe consists of the body 1 with the press walls 2 and 3. The body 1 has the clay-binding medium matrix 4, mixed particles 5 and the texture granules

a * 1
■ t »

6 on. Starting from the texture granule 6 whose longitudinal axis extending tail shaped pores chambers 7, parallel \

to wall 2 or 3 and approximately parallel to the longitudinal axis * §

10 of the chimney pipe runs. This in the illustrated case ll "

play wall-parallel oriented chambers 7 result together I

men nit the arrangement of the granules 6 in the respective |

left corner of the chambers 7 the new one, the temperature change | ^:

Texture that increases resistance, but increases the |

speed of the chimney pipe is not significantly affected. |

The structure of the body and the texture are on the I.

Drawing shown only as an example. Of course, the structure can be made more or less dense with respect to the mixture particles and the texture granules. In addition, the texture direction, ie the course of the longitudinal axis 8 of the chambers 7, can be selected parallel to the wall and at the same time parallel to the longitudinal axis 10 of the chimney pipe . However, it is essential that the texture increases the resistance to temperature changes and the strength of the chimney pipe is not significantly reduced.

Is known, chamotte as well as chamotte substitutes, z. B. porphyry to be used as a framework in tori or in ceramic shards. The addition of granules according to the invention does not lead to the formation of a framework, but to the splitting or loosening of the usually tightly compressed clay masses, as a result of which

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3,

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a thermo-elastic body is obtained. the relatively hard texture granules cut up during the pressing process, preferably parallel to the surface Clay mass, creating a spring-loaded ceramic layer structure arises. However, this desired texture can only be achieved with a hard, abrasion-resistant aggregate achieve that is not destroyed or worn down during the pressing process. It is in the invention Chimney pipe with the texture granulate grain is not a framework, but the opposite, namely a loosened mass, generated. In the invention, a cleavage effect occurring during the malleable deformation loosened the mass and thereby in particular the resistance to temperature changes much improved. This splitting effect is particularly high when the mass is extruded

The loosening results in a further advantage when using clays enriched with bituminous substances in particular, which can outgas better in the fire due to their porosity. Although the body is designed to be much more porous internally than in conventional chimney pipes, the water absorption does not increase significantly compared to the dense body. This is due to the fact that the chamber _s pores are parallel to the outer skin of the flue pipe and not in communication therewith. Which he-

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texture porosity according to the invention is hardly recognizable externally and in no way affects the external appearance of the chimney pipe.

The invention also relates to other extruded ceramic products, such as fireclay products, in which for Achieving an optimal thermal shock resistance, the texture described is generated. The According to the invention, increased porosity, a ceramic product can be produced, which is solely due to the higher porosity has better properties, such as increased thermal insulation or increased suction power on cut surfaces.

Claims (7)

1. Shaped ceramic product, especially chimney pipe, On the basis of clay and chamotte or the like., characterized by a texture im Shards, whereby the texture is formed by pore chambers. 2. Shaped ceramic product, in particular chimney pipe, according to claim 1, characterized marked net that the shard in the cross-sectional image elongated, has closed pore chambers, the longitudinal axes of which are essentially parallel to the wall of the Chimney pipe. 3. Shaped ceramic product, in particular chimney pipe, according to claim 1 and / or 2, characterized that in the chamber corners of the pore chambers each store a rock grain, wherein the aggregates in the respective chamber in the ς - • '-β ·· Il UJl Il < j "Approved Vsrueie * be ■ -" Ejrcrs-sche ^ RBiema-r.t ί ftofessional Represereai-ves De'c-c me European Raien! Otfce V ^ ^■: m SOLF & pin sit in the same corner. 4. Shaped ceramic product, in particular Kanjin pipe, according to one or more of Claims 1 to 3, characterized in that the porosity of the body is between! LO and 25 % . 5. Shaped ceramic product, in particular chimney pipe, according to one or more of claims 1 to 4, characterized in that it has a thermal shock resistance of 15 to 40 test cycles according to DIN 51068, sheet 1. 6. Shaped ceramic product, in particular chimney pipe, according to one or more of claims 1 to 5, characterized in that the rock grains in the chamber corners grain sizes of 2 to 6 mm and have a hardness> 180 N / mm according to Frechen. 7. Shaped ceramic product, in particular chimney pipe, according to one or more of claims 1 to 6, characterized in that the rock grains consist of basalt.