DE1571023A1 - Method and device for covering elongated objects - Google Patents

Description

■ KNAPSACK AKTIENGESELLSCHAFT: -

K 578; ρ Vi 71 023.3

Method and device for coating elongated

Objects.

The present invention is directed to a method for Application of coatings to elongated objects, in particular pipes and profiles.

An essential aim of the present invention is manufacture uniform coatings on such elongated objects that contain aggressive solvents, chemicals or are exposed to corrosive influences, or the electrically insulated v / ground baw. must withstand mechanical abrasion or frictional wear.

Another object of the invention is to produce uniform thick coatings over the entire length of the object.

Finally, the invention relates to the production of such uniform coatings using the well-known fluidized bed sintering process. The latter consists in the formation of a fluidized bed which has a specific, sharply delimited one Having surface, the formation of the-fluidized bed · by Introducing a Ganstrom under a predetermined pressure a gas-permeable plate is carried out into the sinterable coating material. The heated object that has a temperature has that is below its softening temperature but is at least as high as the melting temperature des überzugmaterial.a, is then immersed in the fluidized bed.

For coating the inside and / or outside of pipes from several meters in length by vertical immersion in a container containing a fluidized bed of coating material,

009843 / U74 BAD

very tall containers would be required in which to maintain a uniform fluidized bed is difficult. In addition, such a pipe coating has the disadvantage on that on the first submerged lower part of the pipe, considerably more coating material melts than on the upper part. This is due to the longer dwell time of the lower pipe part in the heated state in the fluidized bed justified.

According to the invention, the elongate article is through an opening corresponding to the cross section of the object and arranged in the gas-permeable plate from below into the Fluidized bed introduced and passed through it upwards. This makes it possible to make the container containing the fluidized bed small. According to the smaller one It is also possible for containers to work with significantly smaller amounts of coating material to be swirled up than is required when immersing in a tall container. The coating thickness is uniform over the entire pipe, because the immersion time is the same for every point on the pipe.

An exemplary embodiment of the invention is from the following description in conjunction with the drawings:

The drawings show:

Pig. 1 shows a side view of a device for coating pipes and

Fig. 2 shows the upper end of a pipe prepared for external coating.

1 with a cylindrical container is referred to, which by an outer annular gas-permeable plate 2 and an inner circular disk-like gas-permeable plate 2 ¹ in

009843 / 1-474 _{BAD 0R1G1NA} L

an upper chamber 15 and two lower chambers 5 and 7 are divided is. The coating material is in the upper chamber * In the lower chambers 5, 7 is through the Lines 11, 12 are supplied with air passing through the gas-permeable plates 2.2 'enters the upper chamber and converts the static coating material into a fluidized bed.

Located between the two gas-permeable plates 2, 2 ' there is an intermediate space 3, which has the shape of the cross section of the object to be coated and in the present case Case is designed as a circular ring. On the inside of the Chamber 5, a cylindrical guide rope 4 is arranged. This guide part 4 is a second cylindrical guide part 6 opposite, which at the same time forms the side wall of the chamber 7. The pipe to be coated is denoted by 8. The tube 8 is through the space 3 through pushed down into the fluidized bed in the chamber 15 and carried away upwards through the fluidized bed. 9 and 10 are arranged in the intermediate space annular seals made of elastic heat-resistant material. the Seals have the task of falling through of coating material from the upper chamber 15 through the space 3 to prevent through. The seals 9 are arranged between the guide part 4 and the tube 8 and the seals 10 between the second guide part 6 and the tube 8. With 13 the carrier for the facility are designated. In the upper chamber 15 is also a high or low frequency heater 14 provided. The heating of the tube 8 can also take place outside the device.

Should the pipe 8 only be coated on its outside) so on the upper end of the tube 8 a cap or lid 17 (Fig. 2) pushed on, so that when passing the pipe no powder into the interior of the tube through the fluidized bed got.

009843/147 k

If, on the other hand, the pipe is only to be coated on the inside, it will open the guide part 4 has an annular cover 18 placed thereon, which extends bia above the fluidized bed. Appropriately The coating material is then whirled up only in the chamber 7.

Are profiles of z. B. Ur, X- or L-shaped cross-section coated, the gas-permeable plates 2, 2 ^{f are} exchanged for a plate in which an opening of a corresponding cross-section is present.

With the present invention, a coating of elongated objects of any cross-section is possible, tubes can be coated inside and / or outside.

SAD ORIGINAL

0098A3 / U74

Claims (6)

Claim 1. Process for the inside and / or outside coating of elongated Tubes with powdery, fusible coating material by vortex sintering using a vortex container which is passed through an inside horizontal arranged gas-permeable plate in an upper chamber for receiving the fluidized bed of the coating material and is divided into a lower gas chamber, which in the Upper chamber introduced and with the help of a gas flow rising through the gas-permeable plate into a liquid-like state of suspension, the coating material is brought into contact with the tube preheated to above the melting temperature of the coating material and is placed on it the surface of which is melted, characterized in that that the pipe to be coated from below vertically through an opening corresponding to the cross section of the pipe in the gas-permeable plate is introduced into the fluidized coating material and through it upwards is carried away, the swirling of the coating material inside and outside of the pipe by separate Gas flows takes place. . 2. The method according to claim 1, characterized in that the Heating of the object in the upper chamber of the vortex container takes place by inductive heating. 3. The method according to claim 1 or 2, characterized in that that for the outer coating of the pipe, the upper opening of the pipe upon entry into the upper chamber of the vortex container is covered. 4. The method according to claim V or 2, characterized in that that for the inner coating of the pipe the outer surface dea Rohrea is covered. . ■. ■ ■ ■ -6- BATH ORIGINAL 009843 / U7 4 5. Device for performing de3 method according to one of claims 1 to 4, comprising a container which is divided by a horizontally arranged inside gas-permeable plate into an upper chamber containing the coating material and a lower chamber into which the fluidizing gas is introduced , as well as a device for supplying the fluidizing gas, characterized in that the gas-permeable plate (2, 2 ') has a slot-like opening (3) corresponding to the cross-section of the tube (8), whereby the plate into an inner circular disc (2 ¹ ) and is divided into an outer circular ring (2), which at the same time form the upper cover for the inner and outer gas chambers (5,7), with separate gas supply lines (11,12) being connected to the gas chambers (5,7). 6. Apparatus according to claim 5, characterized in that sealing means (9, 10) are arranged in the intermediate space formed by the inner and outer gas chambers. BAD ORiGiN _ÄL 009843 / U74