Not less than three! gigantic melt filters now have left the
plant of the Kreyenborg GmbH in Münster. Each of these systems of the new type
series Poly presents the biggest screen changer which has ever been
constructed. These giants have been designed for the use in world-scale
polymerisation lines instead of conventional candle filters. With a maximum
throughput of up to 45.000 kg/h, depending on material, viscosity and filter
fineness, these machines move into completely new dimensions.
The latest screen changers of the type Poly are to be recognized already by few
characteristics. Contrary to most of the conventional screen changers, the
housings are designed horizontally, so that the individual pistons are arranged
side by side and not one upon the other. Every piston disposes of two opposed
screen cavities. Screen changers with two or four pistons are available,
whereas the version with four pistons shows a considerably better process
pressure constancy. As usual with the screen changers, a breaker plate and the
stainless steel wire-cloth screen pack are arranged within the oval screen
cavities. Additionally, the machines of the Poly type series are equipped with
special screen retainers. These screen retainers arrange for an always tight
fit of the screen packs and fluidic optimisation. Furthermore, they reduce the
melt volume during screen change as well as the already very low residence time
of the Polymer in the filter.
Kreyenborg, being world market- and technology leader for screen changers, has
put its complete experience into the development of the new screen changers for
polymerisation. It has been managed to design a machine which offers the user
essential economic advantages compared to conventional filter systems in
polymerisation lines. Especially the cleaning of the filters is less complex
and more favourable in price. Owing to the use of inexpensive flat screens all
habitual advantages of a screen changer – like the always continuous production
and the easy handling – are achieved. Thus the machines of the type Poly,
supplied by Kreyenborg, are the first adequate screen changers for world-scale
polymerisation lines.
The biggest version is the Poly 6000x4, which has a total filtration area of
24,000 cm², resulting from 6,000 cm² in each of the four pistons. Depending on
material and viscosity the throughput amounts to up to 45,000 kg/h. The three
machines of this size, which have been delivered now, will be applied with PET
production in the MTR®-process of Uhde Inventa-Fischer. Two filters have been
delivered to Indorama in
