MATERIAU ABSORBANT POUR DISPOSITIF DE FILTRAGE

ABSORPTION MATERIAL FOR FILTER ARRANGEMENT

Abrégé anglais

Abstract of the Disclosure
A method is disclosed for filtering primarily gaseous
media which contain liquid particles or a gas which is
converted to a liquid at a drop in temperature. According
to the method, the gas is passed through at least one foam
plastic body having closed cells, the walls of the closed
cells of said at least one body being perforated.

Revendications

The embodiments of the invention in which an exclusive
property or privilege is claimed are defined as follows:-
1. A method for filtering primarily gaseous media
which contain liquid particles or a gas which is converted
to a liquid at a drop in temperature, comprising passing
said gaseous media through an absorption material comprising
at least one foam plastic body having closed cells, the
walls of the closed cells of said at least one body being
perforated, and separating said gaseous media from said
liquid contained therein.
2. Method according to claim 1, wherein said at
least one foam plastic body is constructed to be com-
pressed so much that said closed cells become at least
partially flattened or crumpled.
3. Method according to claim 1, wherein said at
least one foam plastic body comprises material selected
from the group consisting of polythene, polypropylene,
and a copolymer of polythene and methacrylic acid.
4. Method according to claim 1, wherein said at
least one foam plastic body is made of an elastic material.
5. Method according to claim 1, additionally
comprising the step of compressing said absorption material
to remove liquid absorbed therein.
6. Method according to claim 5, wherein said
absorption material is compressed by passing said material
between rollers.
7. Method according to claim 1, wherein said
absorption material comprises a plurality of foam plastic
body particles contained in a casing.

Description

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The present invention relates to absorption
material for a filter arrangement.' The in~ention also
concerns a method for filtering primarily gaseous
media which contain liquid particl~s or a yas which is
converted to a liquid at a drop in temperature.
Suction means are generally used in premises
where troublesome gases are formed, these means including
a ~ilter to collect constituents which shall not be released
to the environment outside said premises. Filters to
collect troublesome constituents in the gases are also
arranged in front of the outlet openings of material
emitting troublesome gases. Carbon particles has
hitherto been used to provide such absorption material.
It has been found in practice that such filters with
carbon particles are not efficient enough to eliminate
liquid particles from flowing gaseous media.
An object of the present invention is to effi-
ciently take care of liquid particles in flowing gaseous
media. This is achieved by using one or more bodies
including closed cells which have been perforated. The
bod,ies may suitably consist of foam plastic in which the
closed cells have been perforated.
This invention relates to a method for filtering
primarily gaseous media which contain liquid particles
or a gas which is converted to a liquid at a drop in
temperature, comprising passing said gaseous media
through an absorption material comprising at least one
foam plastic body having closed cells, the walls of the
closed cells of said at least one body being perforated,
and separating said gaseous media from said liquid
contained therein~
A filter may be formed by one or more parallel-
epipedic blocks or it may consist of a casing containing
a number of smaller bodies of different shape which have
b~en eompressed,.
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A ~ilter can also be produced from a body shaped
as a mat or strip which is rolled to suitable shape and
placed in a casing.
The absorption material in the filter is
suitably elastic. In such case the material in the filter
can be subjected to compression so that the constituent
absorbed from the gaseous medium flowing through the fil-ter
can be recovered.
The absorption material in the filter suitably
consists of polythene, polypropylene or a copolymer or
polythene and metacrylic acid. Further characteristic
features of the present invention are revealed in the
following claims.
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The absorbtion material according to the invention invention is pre-
~erably manufactured from a polythene granulate whlch ls mlxed with
small quantities of powdered additl~es with the obJeot of forming
bubbles~ The mixture is fed into the first stage of a two-stage
S extruder of ~crew type and is heated to ¢a.200C. The melt obtained is
fcd into the seoond extruder stage where the temperature i~ lowered to
100 - 150C and i9 extruded through an annular nozzle. A porous tube
is obtained and the tube i3 oooled internally and externally ~ith alr
and then cut in longitudinal direction to form a strip of ~oam plastic.
Parallel-eplpedic bodieQ may of course be formed instead of strips.
If parallel-epipedic bodies are produced, they are suitably placed in
the frame of a filter arrangementO If a mat is used, however, it must
be rolled up, suitably shaped and inserted in a casing which is then
placed in a filter arrangement.
According to the invention the mat or parallel-epipedic bodies may
also be disintegrated into small particles. A casing i9 then filled
with said small particles and placed in a filter arrangement.
A filter arrangement of the type described above functions in the
following manner. Gas containing liquid drops is allowed to pass the
filter arrangement, ~hereupon the liquid drops are caught by the ab-
sorbtion material and, i~ the ~as contains COnQtitUentS which are
¢onverted to liquid at a drop in temperature, the liquid formed in this
way will also be absorbed. When the filter arran8ement is saturated~
the absorbtion material is removed and replaced by fresh material. The
absorbtion material in the saturated filter is then ~ubjected to com-
pression whereupon the material absorbed can be recovered for re-use.
After compressing the ab30rbtion material is once more usable. An
absorbtion material has thus been produced which not only absorbs
liquid particles, but also enables recovery of theQe particle~ ~o that
the material i~ onoe more usable as a filter.
An endless 3trip can be produced ~rom the mat of abQorbtion material
mentioned above. This ~trip i9 then allowed to run over two rollerQ~

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one of whioh i9 driving. A strip arranged on roller~ i9 plaoed in a
filter arrangement so that a ga~ i9 allowed to flow through one part Or
the strip and then a qeoond park of the ~trip. The skrip will thu~
ab~orb liquid partioles whioh oan be reoovered if an additional roller
i~ arranged by one o~ the rollers~ presqing agaill~t the ~trip. ~aoh
part of the strip will therefore be supplied with eas oontaining liquid
partioles on two different oooasion~ and the liquid absorbed i9 then
pres~ed out bet,ween the two oooperating roller~.