This bachelor degree thesis was assigned to us in the fall semester of 2001.
The purpose was to redesign a machine for the company Asea Brown Boveri (ABB)
in Karlskrona. ABB HVC in Karlskrona is manufacturing high voltage cables.
Amongst these the seacables are the largest and most complex. The seacables are
heavy naval cables and lies on the bottom of the sea. For these heavy-duty
applications the cables need good armouring. The armouring, which is made of
steel, needs a corrosion protection layer that is very wear resistant. For this
ABB uses industrial bitumen, a form of asphalt. The cables run through a whole
production line where the bitumen is applied on the cables at a temperature of
160°C. In this working station the cable armouring wires are winded on the
cable and the bitumen is applied.
The present machine is old and needs replacement. In fact the whole AR 50 line
is in plan for restoration. This project is to redesign the bitumen application
machine and eliminate the present problems. The machine still works, but not
satisfying. It is a hazardous workplace when the bitumen is a very dirtying
media that sticks to almost everything and it is very hard to clean. It is also
very hot and a splash could burn a person. There is also a problem with slag
products from the armouring in the surplus bitumen.
The main work has been concentrated on eliminating the larger problems and
develop a well working machine that is easy to run and maintain. By applying
Fredy Olssons method for product development the work has proceeded step by
step. The work started with finding different concept solutions. To simplify
the work the machine was divided in four parts, the container for storage and
heating, the nozzle for transporting and spreading the bitumen on the cable,
the reservoir for collection of the surplus bitumen and to separate the slag
particles and the table to hold the distribution rings and the adjustment
screw, this to get a better view of all parts and components. These ideas from
this phase where evaluated with main focus on the criterions. For al the four
units one solution was filtered out for further development.
In the primary construction phase the concepts where transformed in to a whole
machine. This phase contains research of components and detail construction of
unique parts. Small adjustments of the concepts from the first stage had to be
made to create the best solutions.
The machine process can be described shortly. From a main tank outside the
building the bitumen is transported to the container where it is reheated to
160°C. From this container the liquid is pumped up through a heated pipe and by
a nozzle spread over the cable. On the cable two rings spread the bitumen as a
smooth layer on the cable. The surplus bitumen will fall down in to the
reservoir where the slag partic...
