TPT September 2008

eptember

2008

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4.4 Tube tracking control (TTC)

Tracking of the tube is achieved in different ways:

based on the theoretical calculation the position of

the tube or tube sections is determined with the HMD

signal in front of the mill and the speed measurement

at the entry side.

Additional HMDs are installed between certain stands

in the block. With each HMD signal the track position

is corrected to the actual position. Another correction

of the tracked position can be carried out with a load

detection of the motors. However, this detection is

only possible for mills with individually driven stands.

4.5 Neutral place correction (NPC)

The exit speed of the stretch reducing block can be

kept almost constant by using the integrated NPC

function. There is always a ‘theoretical’ position in the

block, where the circumferential speed of the roll is

equal to the tube speed. This position is called ‘neutral place’.

The NPC functions always keep the speed for the neutral place

constant. By shifting the neutral place to a different position for the

different rolling phases of the tube – such as entering the block,

stationary situation, exiting the block – the exit speed can be kept

constant. Different neutral places can be selected in the Tumicon

Inspect and can be changed during the rolling of the tube.

4.6 Tumicon Inspect

The Inspect system is a visualization tool for the technological

functions of the TecBox. Inspect loads the requested values from



Figure 6

Tumicon remote control



Figure 5

Main screen Tumicon inspect

In case of a new Kocks SRB or stretch reducing mills with individually

driven stands, a minimum number of stands are used for the tension

control to influence the wall thickness over a minimum length of the

tube. The parameters are loaded from the Tumicon database; the

user can restore individual corrections in the database.

4.3 Heavy end control (HEC)

Due to the applied tension, heavy ends are created at the head

and tail of the tube. The HEC of the Tumicon TecBox minimizes this

effect and leads to a higher output of the mill.