Lonza Inc.

Norbert Richle

Hansjorg Furrer

Willi Heusser

Dietrich Ulrich

Guido Huber

Raimo Peltoniemi

Beat Eckert

An apparatus for applying a descaling agent to the inner surface of a red-hot hollow billet in the production of seamless tubes.

Device for applying a descaling agent to the inner surface of a hollow

The device has a storage vessel (2) that is connected to a compressed gas pipe (1) and whose outlet (6) discharges through a shut-off element (7) into a carrier gas pipe (10). Shut-off element (7) and the setpoint values of a first pressure regulator (23) in compressed gas pipe (1), as well as a second pressure regulator (24) in carrier gas pipe (10), are controlled by a program control device (33) with a program memory (34), in which several programs that are selectable by a selector (37) for charging the carrier gas stream with varying amounts of material and/or material concentrations are stored. Each program contains time-driven switching commands for opening and closing shut-off element (7) and two different setpoint values for first and second pressure regulator (23, 24). With the device, the carrier gas stream, for example, for descaling hollow billets of varying dimensions, can be charged selectively with different, precisely measured amounts of material and material concentrations (amounts of material per carrier gas volume), by which charging with different amounts of material or material concentrations can be done in quick succession.

Process for charging a carrier gas stream with a free-flowing material

Hollow billet (13) in a first operation of a piercing mill (1, 2) is advanced over a piercer (10) placed on front end (5) of a piercer rod (6) and is retracted after removal of the piercer. During the advance of hollow billet (13) a lubricant is applied to the hollow billet inside wall processed immediately before by piercer (10) with the help of an inert carrier gas current through outlet openings (16, 17) on front part (14) of piercer rod (6). In this way the lubricant is distributed uniformly on the hollow billet wall in the first operation for processing in the second operation of the piercing mill and in the latter for processing in a third operation (in a reeling mill). Thus, no delay whatsoever occurs in the processing, i.e., the operations can be performed without interruption successively, and no environmental pollution by the agent occurs.

Process for making hollow billets into tubes

The material is applied to the inner surface by means of a carrier gas stream, provided with a swirl, conducted through the hollow space. To prevent or reduce the swirl loss, which occurs if the laden carrier gas stream, provided with the swirl, forces the stagnant air in the hollow space from this space and then the loss develops by friction on the inner surface, before and during the flow of the laden carrier gas provided with the swirl, an additional gas, not laden with the material, is conducted through the hollow space with a siwrl, whose direction of rotation corresponds to the swirl of the laden carrier gas stream. For this purpose, the device has on the outlet of a passage element (1), equipped with a swirl-producing device 3 for the laden carrier gas stream, outlet nozzles (4), which feed to the laden carrier gas stream the additional gas with a swirl, whose direction of rotation corresponds to that (5) of the swirl-producing device.

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Remetschwil, Switzerland

Norbert Richle