DE2219392A1 - METHOD AND DEVICE FOR THE MANUFACTURING OF ASBESTOSCEMENT PRODUCTS - Google Patents

Description

Herne, 8000 Munich 23,

Freiligrathstraße 19 rt-ii η (J E> I. .. Eisenacher Slraße

P.O. Box 140 Dipl.-Ing. RH Bahr _Pai _ _{AnwBelz [er}

Pat. Herrmann-Trentepohl D Ϊ DI - P hVS ΕαίΙβΓαΒθίζΙβΓ Telephone: 39 BO11

Telephone: 51013 I * · J "39 8012

⁵¹⁰¹⁴ Dipl.-Ing. W. Herrmann-Trentepohl ^ ⁸⁰¹³

Telegram address: Telegram address:

Bahrpatente Herne PATENTANWÄLTE Babelzpat Munich

Telex 08229853 Telex 5215360

Γ ~ 1 bank accounts:

Bayrische Vereinsbank Munich 952287 Dresdner Bank AG Herne 7-520 Postscheckkonto Dortmund 55868

Ref .: MO 3483 B / ks

please indicate in the answer

Please send a letter to:

Munich April 19, 1972

EVERITUBE, 24, Rue de Prony, 75 Paris / France

Method and device for the production of asbestos cement products.

The invention relates to the manufacture of Äsbest cement products, such as pipes or other tubular bodies, connectors, square and rectangular ventilation pipes etc. esp. the invention relates to asbestos cement products that do not undergo steam treatment are to be subjected to pressure in the autoclave »

It is well known that the requirements placed on finished asbestos cement products and in particular on pipes are very high. Therefore The production includes a ripening process that requires a sufficient amount of water to be as complete as possible To achieve hydration of the cement «taking the quality of the manufactured products, the more complete the hydration, the higher it is.

309830/0781

- 2 - 9

In the known processes for the production of asbestos cement products water must be added so that in the initial stage of manufacture of the product there is a there is generally sufficient water to set and harden the cement.

When setting and hardening of asbestos-cement pipes, which takes place after the pipes exit the molding machine, lose the products more or less moisture by evaporation of the water by the fact that the pipes of the hall temperature are exposed, or by passing them through ripening chambers or tunnels, where they, especially in the case from pipes are exposed to evaporation due to the exothermic reaction of the setting process of the cement is favored. This brings with it the risk that the amount of water remaining in the products for a optimal hydration, especially in unfavorable atmospheric or curing oven conditions, is no longer sufficient.

In order not to fall below the required minimum amount of water, the asbestos-cement pipes or products after they exit the maturation tunnels or rooms, or after they have been exposed to the air at hall temperature are put under water. Watering is done by sprinkling or immersion, with the duration of hydration Usually 1 to 4 weeks is »Sprinkling or immersion is intended to prevent the water from escaping from the cement and if necessary add water to the cement, if the Minimum amount of water should not be available. Both hydration methods, however, require significant handling Waiting work.

It is also known for certain applications asbestos cement pipes or other asbestos cement products with a

309830/0781

Cover to protect against very aggressive floors and water to provide. Depending on the intended use, the coating materials are generally substances based on bitumen or coal tar or other products that can take on the role of a protective layer.

The coating is carried out according to a method known for pipes when the pipes are machined and, if necessary. have been checked on the test press, what after Setting and hardening occurs, i.e. when they are sufficiently matured and hydrated. It is a period of time from one to four weeks or more between the end of actual manufacturing or molding and coating, this time with the above hydration work and treatments and waiting times and if necessary. with a storage is filled out. In order to carry out hydration, mature pipes are also immersed in a water bath, so that they dry superficially and them at the same time water is supplied again, which could have been lost in the course of storage.

It is also known to use asbestos cement products, esp. Panels, either after superficial drying or while they are still in a moist and malleable state, a methyl methacrylate polymer by means of an aqueous dispersion to raise. The purpose of this treatment is to avoid stacked products stick together and develop efflorescence or water marks form. The products can then either be consumed or subjected to steam treatment in an autoclave be subjected. In the latter case, the coating is used in particular to avoid efflorescence.

The object of the invention is, in the production of asbestos

309830/0781

cement products, esp. of tubular bodies, both avoid lengthy and costly hydration as well as additional handling and storage operations, which are particularly expensive if, in addition, after dipping or spraying and possibly. after going through a Test press any coatings are to be applied.

To solve this problem, in a method for production of asbestos cement products according to the invention on all surfaces of the product after a waterproof layer Start of setting so that the products show sufficient dimensional stability at that moment, and before At the end of the hardening process, applied to the extent that the amount of water present in the products ensures optimum hydration enables.

This method is surprisingly feasible because the water that is in the products due to the normal manufacturing process, or a special process involving hydration in which the products After leaving the molding machine, go through a heated room, there is enough to get a correct one To ensure friction, so that only the leakage of this water needs to be prevented. It turned into similarly surprisingly shown that the usual coatings for protection against corrosion by certain Water and soil can be applied without difficulty from the end of the setting of the cement and thus the leakage Prevent the water from leaving the product, so that the ripening process can be prevented by immersion in water containers or by sprinkling or spraying with water becomes unnecessary.

Resulting from the elimination of the ripening processes under water

309830/0781

considerable profitability. In fact, the pipes or other asbestos-cement products, which are used in the absence of aggressive soil or water under normal conditions without a coating could be produced more economically by the process according to the invention than by conventional tireing is possible under water.

According to a further advantageous feature of the invention, the waterproof coating is applied to the products briefly immersing the same in a water bath. This immersion in a water bath is required if the setting and the onset of hardening took place under conditions under which those during the Shape of the product present amount of water compared to that necessary to achieve optimal hydration necessary, has been reduced, e.g. due to the passage of the products through a heated room. In this A particularly advantageous case is the application of the coating when it exits the water bath performed. The task of the waterproof coating is to prevent the asbestos-cement product from escaping to prevent the water contained in it from being immersed in order to finally keep the amount of water inside the cement, which is necessary and sufficient for optimal hydration.

The method according to the invention is of particular interest because the coating can already be applied when the product has sufficient dimensional stability, in order to be able to process it further after it leaves the production line. Thanks to the choice of the most favorable moment for the application of the coating to the products, the ripening is simplified and by eliminating it a long sprinkling time and a long storage in

309830/0781

Water baths shortened and therefore a much improved one Handling and storage achieved as well as the requirements for structures, transport equipment, basins, sewers, pumps, etc. Like. Reduced. Known substances can be used for the coating, which can be applied in one or more layers on the basis of bitumen, coal tar or petrol pitch, but also use all other waterproof products. - In the In contrast to the known processes listed above, according to which the products also have a layer for protection against Corrosion and bonding is applied, according to the invention, the layer at the beginning of the setting and ripening and in Applied at a moment in which the products already have a certain dimensional stability. As a result of the at The process of ripening and hydration is complete and the quantities of water present in the products are produced undisturbed. By the method erfindungsgeiru ie Avoid interruption or reduction of the hydration process at a point in time that is detrimental to the quality of the product could be inconvenient. In addition, the unfavorable influence of an excessively long exposure time of the uncoated Pipes in the sun or in the wind in storage areas or in storage areas, especially in countries with hot and dry areas Climate, avoided.

Because the layer is expediently applied after a short immersion in a water bath, there is only a small water basin necessary. An immersion time of a few minutes is sufficient for water absorption to ensure undisturbed hydration the end.

By immersing the products in a heated water bath, rapid water absorption and rapid absorption are achieved Drying of the pipe after removal from the water. There

309830/07 81

2219382

the water on the surface evaporates and therefore none If water droplets remain, the layers can be applied particularly quickly, safely and without disruption.

If you apply the layer to the still warm products, a quick drying of the layer is achieved.

The invention also has the object of a production line for carrying out the method, one behind the other a manufacturing machine for the asbestos cement products and a station for applying a waterproof coating having.

This production line has a much smaller one Space requirements compared to the known systems, the storage and handling areas for the sprinkling and / or numerous Have immersion basins.

The drawings show an embodiment, namely in

Fig. 1 is a schematic perspective representation of a plant for the production of asbestos cement pipes according to the method according to the invention, and in

2 shows a schematic individual representation of the coating installation belonging to this installation.

According to the embodiment of FIG. 1, the inventive Procedure carried out with the aid of a system that contains the following parts:

A machine 1 for the production of asbestos-cement pipes T, a hardening furnace 2, which is generally heated to a temperature of, for example, 40 to 140 ° C., and a water basin 3

309830/0781

a temperature that corresponds to the types and cycle times of the Pipes is adapted to a cutting machine for cutting the asbestos-cement pipes on a predetermined one Length, a system 5 for processing the pipe ends with a view to the subsequent connection of the pipes and a system 6 for applying a watertight protective layer on all sides to the asbestos-cement pipes. The pool of water corresponds in its width, measured across the production line, to the largest pipe length dimension and is in its Length, i.e. in the direction of the production line, greatly reduced, i.e. essentially dependent on the diameters of the pipes to be produced. It should also be noted that the water in the water basin 3 can be heated.

In the illustrated embodiment, the system or station 6 is for the simultaneous application of a protective layer designed from the inside and outside, which can consist of bitumen, coal tar or petroleum pitch. Two horizontal Rails 7 allow the pipes to be transferred from the water basin 3 to the systems or stations 4, 5 and 6 and their discharge beyond Appendix 6.

The reproduced system works as follows:

The tubes T leaving the molding machine 1 have a winding core usually made of steel. This winding core can be removed and replaced with an auxiliary core made of wood or thin sheet steel or with a plug, to avoid deformation of the ends. The tubes T enter the hardening furnace 2. They pass through this furnace, in order to achieve sufficient dimensional stability for subsequent processing as quickly as possible through rapid initial hardening to reach. In the curing oven 2, the core

309830/0781

or auxiliary core or the end plug from the tubes T removed will.

Since some of the water present in the walls of each pipe may be lost in the curing oven 2, each The pipe emerging from the curing oven 2 is immersed in the water basin 3 in order to provide hydration in the pipe walls to restore a sufficiently high water content. The pipe remains there for a short time, for example a few minutes instead of 1 to 4 weeks as with the known methods. Each tube T leaving the water bath must drain and enter the cutting and processing systems 4 and 5. If the water droplets present on the surface evaporate are, the inner and outer protective coating, for example tar or bitumen, is applied to the pipe in Appendix 6. At this point in time, the pipes T have achieved sufficient dimensional stability with a sufficient amount of water. In practice, only a short time elapses between the exit of the tubes from the water bath 3 and their coating in the Shelf 6. You can, however, also specify the duration of immersion if necessary Extend the pipes in Appendix 6 before coating.

The coating system 6 contains, as Fig. 2 shows, support and transport rollers 8 for rotating each tube T around its own Axis X-X using a group of gear motors Q. The tubes 8 are outside the rails 7 with horizontal and lying transversely to the general direction of manufacture, to one another arranged parallel axes. The system 6 also contains a carriage 10 with two to the pipe axes X-X parallel tubes 11 and 12. The carriage 10 can be on a Track 13 to be moved back and forth, the extension

3098 30/07 81

- ίο -

the axis X-X of the tubes T runs. This driveway has a Length that corresponds to the length of the pipe T plus a short flow and return path.

The carriage 10 is for this purpose by a cylinder-piston device 14 or some other equivalent device with rectilinear reciprocating motion. The tubes 11 and 12 are arranged at such a level that the one tube 11 engages inside the tube T above the inner lower surface line and the other tube 12 comes to lie on the outside over the outer upper surface line. The tubes 11 and 12 for feeding the Tar or bitumen for the coating has a nozzle or spray nozzle 15 at its foot end At fixed ends they widen in a funnel shape 16 and 17 and lie under the free ends of the tubes and 19 », which merge into a flexible tube 20, which with is connected to the fixed container 21 for pressurized tar or bitumen, which is only is partially shown. When applying gas pressure to the bath level of the bitumen or tar in the container 21 the coating material through the tubes 11 and 12 and the nozzles 15 sprayed during the rotation of the tube T around the axis X-X, the carriage 10 and thus the Nozzles 15 are moved along the surface line of the pipe T. Thus, an inner protective layer 22 and an outer protective layer 23 is applied to the tube T at the same time.

That way with their waterproof protective layers

ο
Pipes T provided with 22 and 23 are moved over the rails 7

discharged to a drying line. The drying will

309830/0781

favored if after passing through the curing oven 2 and the basin 3 the pipes at the time of attachment the waterproof protective layers are still warm.

The invention thus enables the times for the ripening processes of the asbestos-cement products to be shortened considerably and a simplified and less extensive system without sacrificing quality of the manufactured products happens. Rather, they achieve essentially the same strength such as those that are produced by known processes, and are against later drying out in storage areas or the like protected. This drying out can, under certain circumstances, lead to a reduction lead to strength and in particular to a loss of tightness. From this point of view, the Invention of products that have a more regular and even better quality.

Patent claims:

3 0 9 8 3 0/0781

■: ■■ -; α \ y ε 8 ρ ο ι

Claims (14)

Claim a patent Process for the manufacture of asbestos cement products, characterized in that after shaping a water loss preventing layer on all surfaces of the products after setting has started and applied before the end of hardening and thus the amount of water present in the products on one for the Hydration is kept at an optimal level. 2. The method according to claim 1, characterized in that g e k e η η -. indicates that the waterproof layer is applied as soon as the products have been shaped in such a way have sufficient Pormstabil that they are self-supporting. 3. The method according to claim 1 or 2, characterized in that the waterproof layer according to a brief immersion of the products in a water bath. 4. The method according to claim 3, characterized in that the immersion immediately after a heating of the products is carried out, which itself directly affects the shaping of the products follows. '_ ■ .... 5. The method according to claim 3 or 4 »characterized in that the products in a heated Be immersed in a water bath. 6. The method according to one or more of the claims 309830/0781 3 to 5, characterized in that the Products can only be immersed in the water bath for a few minutes. 7. The method according to one or more of the claims 3 to 6, characterized in that the waterproof layer is applied at the exit of the water bath as soon as the water on the surface has evaporated. 8. The method according to claim 5, 6 or 7 »thereby achieved * indicates that the layer is still on warm products is applied. 9. The method according to one or more of the claims 3 to 8, characterized in that the layer on the product immediately after leaving the water bath is applied, the immersion in the water bath immediately after the product emerges from the Maturity tunnel takes place. 10. The method according to one or more of the preceding claims, characterized in that g e k e η η ζ e i c h η e t, ' that a waterproof layer of bitumen, coal-tar pitch or petroleum tar pitch or other at least equally impermeable to water and water vapor Materials is applied. 11 «Device for performing the method according to one or more of the preceding claims, characterized by a behind a manufacturing machine (1) the following system (6) for applying a waterproof layer to the product, 12. The device according to claim 11, characterized in that 'g e k e η η * - 3ÖS830 / Q781 indicates that between the manufacturing machine (1) and a ripening room (2) and a water bath (3) are arranged in the coating system (6). 13. The device according to claim 11 and / or 12, characterized in i; that before the coating line (6) a separating (4) and processing system (5) are provided. ir 14. Device according to one or more of claims 11 to 13t, in particular for the application of the method according to one or more of claims 1 to 10 to tubular asbestos cement products, characterized in that the coating installation (6) has a coating material container (21) and spray nozzles (15) connected to these »support and. Transpori organs (8) for successive Recording of each product to be coated "I. Certificate, (T) and devices (10, 14) for actuating the spray nozzles (15) and the transport elements (8) relative having to each other. 303830/0781 Blank page