Sink roll bush structure improvements(3)

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-Sink roll bush structure improvements 3

c. Considering the material expansion coefficient of Sellite6 alloy and 00Cr17Ni14Mo2 is not the same. The proper clearance retained between part 2 and part 4. And to prevent zinc adhesion between part 2 and part 4 causes applied force to part 2. That is because sink roll bush returned to normal temperature after bush off lined.  Similarly the graphite gaskets installed in the gap between part 2 and the part 4.

d. After rollers mounted the gap between the shaft end and the bush inner end is less than the gap between the roll end and the roll arm stopper. Consequently the actual use of the process it could easily lead to shaft end wear at first then the roller head was worn after. Therefore Sellite6 alloy part (part 2) put to the bush in the middle in order to increase the gap between the inner roll arm and sink roll shaft end.


3. Conclusion

Through the four improvements of optimizing the bush structure we resolve the problem of the stall and crack in the production. It greatly extended its working life.

After Improved structure of the liner – Figure 4.
After Improved structure of the liner – Figure 4.



Sink roll bush structure improvements (2)

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The cracks were found on Stellite6 alloy block part after the structure put into use a period. After analysis the cause of cracks is the welded structure of Stellite6 alloy block and sink roll bush body. In the production the line is under high temperature environment of greater than 600 ℃.The state returns to normal temperature after the offline. In this process of expansion and contraction, Since Stellite6 alloy material is different with bush body material 00Cr17Ni14Mo2, the thermal expansion coefficient is different, so that Stellite6 alloy subjected to tension and pressing force, thus cracks even breaks were found at weld position. See figure2.

 Fig2 sink roller bush after use

Figure 2 sink roller bush after use offline

From whole assembly drawings (Figure 3) The clearance between carbide block and sink roll sleeve end is 13 mm, while the spacing between sink roll head and stopper block is 15mm. That means actually the head did not play the effect of reducing friction area.

2. Improved sleeve

In order to avoid recurrence of the above two cases, the bush re- designed and the assembly form changed. See figure4 Improved bush structure

a. Due to the action in the course of the strip steel, the actual contact surface of the roll sleeve and the bush is in the upper part of the bush. Therefore, the Sellite6 alloy blocks changes to one unit which can still meet the requirements and also reduces the manufacturing cost.

b. As for Sellite6 alloy part (part 2) installation, two stoppers (part 3) welded at two sides and 2 semicircle with material 00Cr17Ni14Mo2 (part 4) welded at the lower half of the body to support. Not to weld Sellite6 alloy directly with 00Cr17Ni14Mo2 body which reduce the difficulty of construction and potentially dangerous.


Figure 3 original bush assembly drawing
Figure 3 original bush assembly drawing

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