TPT July 2016

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JULY 2016 79
AR T I C L E
Dalian Field
Dalian Field – China
Tel: +86 411 83192715
Fax: +86 411 83192716
Email:
Website:
floor space, land, water, electricity and so on compared to an
ordinary line. This is a great advantage and profit, and not only
a question of raising the speed to 150 or 200m/min.
We have already stated that the real and only irreparable
bottleneck of the speed limit is the cut-off. All ways and means
were used to solve this problem, such as double- and triple-
blade milling saws, and even saws with four milling blades.
But given the limited time for making the cut, these applications
also turned out to be very limited. To raise the productivity of
the milling saw, we have to increase the cutting time. To
increase the cutting time, the only way is to increase the
number of the saws, including increasing the number of multi-
blade saws, and not only increasing the number of blades.
Compared to speeding up the milling saw itself, the double-
cart saw has enough time to make the cut, lifetime of the
blades is longer, and the cut-off quality is better. Calculations
and production practice show that at the same line speed the
time for making the cut of the double-cart saw is two to four
times longer than that of a single-cart saw. Or, in other words,
with the same work intensity of the saw, you can raise the line
speed two to four times. Also, the double-cart saw has got
more time for cutting those not easy to cut thick-wall tubes,
and this is very important for heavy mills and mills for special
material products.
In the near future, due to the use of the dual-cart milling
saw cut-off, high-productivity tube mills will get a great
advantage in the market and will become the main trend in
tube production until a new concept of cut-off is born. Tube
producers will gradually realise that as the line speed is an
important issue when choosing tube mill equipment, the basic
point is the speed of producing your main product, and not
the “nominal” speed of the line quoted by the mill equipment
producer. “Nominal” speed is the highest speed performance
of the mill, but the speed of producing your main product and
your mill real production capacity might be much below your
expectations, which may negatively influence your market
competitiveness.
Four-blade
milling saw
Double-cart milling saw
Tube mill using
the double-cart
milling saw