DE2213452C3 - Method and device for drying enamel slip on the inner surface of pipes - Google Patents

Description

The invention relates to a method for drying enamel slip on the inner surface of Pipes by induction heating of the latter.

It is well known that the slip applied to the pipe surface contains a great deal of moisture. and / was up to 40 ¹ Vb of the Hmail frit weight.

During the heating process, the pipe usually becomes by any suitable drive! orsi spreading, along its] · axis, relative / u one encompassing it Moved heating coil, the tube is gradually heated in the longitudinal direction. i.e. in each At the moment, the pipe part located in the heating coil zone is heated, while the rest of the pipe is not in the The part located in the hot / .coil zone remains cold.

Therefore, when the slip coating dries out, water vapors form in the heated part of the pipe Rise up the pipe shaft in the direction of the cold pipe part, where they (based on the principle of the return cooler) be condensed. The resulting condensate flows down and washes the one that has been applied to the inner surface of the pipe Email slip from.

! ■ '■ - The aim of the invention is to address the disadvantages mentioned remove.

Hs is said to be a perfect method of drying of the enamel slip, which prevents condensation from forming, and a device to carry out theses procedure who created the.

In the following, such a drying process is applied to the inner surface of the pipes Enamel slip. at the induction heating eye turns wildly, described. l'riindinigsgomäß exists Perfection in there. that the during de · - Off When the slip is dried, vapors are extracted from the inside of the pipe directly in the zone of the heating coil will.

At the same time, the invention provides a device which enables the above without difficulty Carry out the described procedures. This device has a stationary mounted heating coil and an antiiob for the progressive shifting of the Tube along its axis and through this heating coil, ίο According to the invention, this device has an in the heated pipe, one end of which is in the heating sink zone and the other end End is outside the tube, with a suction device connected to the latter.

The end of the riser pipe located in the heating coil zone advantageously consists of a perforated head, to be able to extract the vapors better.

Now it is possible to dry the enamel coating on the inner surface of the entire pipe shaft, as the Steam ^ sucked off directly in the heating coil zone; and will not rise in the shaft and no. Condensate forms in the unheated part of the pipe.

The invention is described below with reference to the drawing, in which the device for performing the according to the invention Procedure is illustrated, described in detail.

It can be seen from the drawing that a heating coil 1 is rigidly attached to a frame 2 which is mounted above a shaft 3 and is connected to an unformer 4. To improve the power factor under load, a capacitance 5 is connected to the heating coil circuit. A tube 6 with a layer of enamel slip (not shown) is pushed through the heating coil 1 along its axis in the direction indicated by arrow A with the aid of any suitable drive (not shown).

In the lower part of the shaft 3 is a vertical one Riser pipe 7 attached, which is led into the pipe 6, around which during the heating of the Tube; ·, 6 forming when the slip dries Extract fumes. A suction head at the upper end 8 of the riser pipe 7 is located in the zone of the heating coil 1 and has numerous openings 9 through which the vapors flow. The openings 9 are in the whole annular zone of the heating coil 1 is provided. At the lower end protruding from the tube 6 OK of the riser 7 is a suction device via a pipeline II 12 (fan) connected.

The inner cross-section of the riser pipe 7 is slightly below the pipeline 11 through a sloping floor Π completed. The latter serves to divert the water condensed from the vapors into a collecting tank 14, from which it is discharged via a pipe 5 by a pump 16.

The drying process according to the invention can be illustrative can be explained by the operation of the device.

The pipe 6 is displaced relative to the Heizspu-Ie during the E: scratching in the direction indicated by the arrow Λ. Water vapors that form when the slip applied to the inner surface of the pipe dries are sucked off by the ventilator 12 via the riser pipe 7, so that no vapors get into the unheated (upper) part of the pipe f>. The water partially condensed from the vapors, however, flows through the inclined bottom 13 of the riser pipe 7 into ilen container 14 'through the pump 16 from this

Thanks to the measures taken, after the Baking enamel slip of uniform thickness and a structure that is characterized by high characteristics of the physical-cnemical properties. <,

In addition 1 Blair drawings

Claims (3)

Patent claims: 1. Method of drying enamel slip on the inner surface of pipes by induction heating, in which a heating coil and the tube passed through it along the axis of the latter relat'v are shifted to each other, characterized in that that the vapors produced during the drying of the slip from the The inside of the pipe can be extracted directly in the zone of the heating coil. 2. Apparatus for performing the method according to claim 1, which has a stationary mounted, the Tube comprising heating coil and a drive for progressively displacing the tube along it Axis and relative to the heating coil besiut, thereby characterized in that it is inserted into the tube (6) Has riser pipe (7), one end (8) of which is in the zone of the heating coil (() and the other The end (10) is located outside the tube (6), with a suction device (12) connected to the latter End (10) is connected. 3. Device according to claim 2, characterized in that that the end (8) of the riser pipe (7) located in the zone of the heating coil (1) has a large number of openings (9).