ASSYMETRICAL MECHANICAL FILTER

FILTRE MECANIQUE ASYMETRIQUE

English Abstract

ABSTRACT OF THE DISCLOSURE
An assymetrical mechanical filter for filtering
a fluid and solid particle medium such as dust and air
comprising a frame having a folded filter medium disposed
within and a plurality of folded, pleated foils construc-
ted of rigid planar material disposed between folds of the
filter medium so as to space apart the filter medium. The
foils have a larger fold between the filter medium layers
at the dust inlet side than on the exhaust side of the
filter medium so that an improved filtering takes place.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An assymetrical mechanical filter for filtering
and reclaiming powdery material and dust from a gaseous
medium, comprising:
a hollow box-like frame;
a sheet-like, reversely-folded filter medium mounted
within said box-like frame, said reversly-folded filter medium
having a plurality of parallel leaves defining therebetween at
least one pair of alternately-arranged, adjacent generally U-
shaped channels, one of which opens onto the inlet side of said
filter and the other of which opens onto the discharge side of
said filter; and
a plurality of elongated, pleated spacer foils
constructed of rigid material, each of which is disposed in
one of said channels defined by said filter medium, with the
foil disposed in said channel opening on the inlet side of
said filter having a constant and relatively large pleat
height and the foil disposed in said channel opening onto said
outlet side of said filter having a constant and relatively
short pleat height.
2. The assymetrical mechanical filter according to
Claim 1, wherein the height ratio of said pleats of said foil
in said channel on the inlet side of said filter relative to
said pleats of said foil on said exhaust side is between 2:1
and 3:1.

3. The assymetric mechanical filter according to
Claim 1, wherein said foil is constructed of aluminum.
4. The assymetric mechanical filter according to
Claim 1, wherein said foil is constructed of hard paper.
5. The assymetric mechanical filter according to
Claim 1, wherein said foil is constructed of plastic.

Description

10~1138
The present invention relates to a mechanical
filter. More specifically, the present invention relates
to a filter which is used in devices and installations for
reclaiming powder, or more generally in installations for
dust particles.
Known mechanical filters of the above-mentioned
types generally use a tape or strip-like filter material
such as, for example, filter paper, fiber glass material
or the like which is positioned in a folded manner in a box--
like frame. Between each layer of the filter material is
alternately mounted a folded or pleated foil material at
either side of the filter material, so ~s to provide the
required distance between the individual filter medium
layers. In the known mechanical filters, these folded or
pleated foils consist of aluminum, hard paper or plastic
material and are provided with an even fold on the dust
side as well as on the pure gas side. The folded or pleated
foils also act as distance spacers between the individual
layers of the filter medium so that equal distances betwPen
the filter layers are created.
- It is an object of the subject invention to im-
prove the known mechanical filters with respect to their
du8t storage and to enable the filters to be cleaned. In
the known filters, wherein the distance is optically di-
mentioned with respect to the prevailing air speed, it has
been shown that the filters become plugged up very rapidly
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101B113B
due to the fact that the cxoss sections of the filter mat-
erial are reduced by the dust material flowing therethrough
and separated by the filter material.
It is therefore an object of the present inven-
tion to provide a mechanical filter of the aforementioned
type which is assymetrical and wherein the folded or pleat-
ed foil, which acts as a distance spacer between the indi-
vidual layers, has a wider and larger fold on the dust side
of the filter medium than on the pure gas side.
In accordance with a preferred embodiment of the
invention, the ratio between the large fold on the dust side
with respect to the smaller fold on the pure gas side is
about 2 : 1 to 3 : 1, depending on the type of filter mat-
erial used. -The performance of the filter is defined in
accordance with the required mechanical-filter material per
filter element. In order to maintain the sguare meter di-
mension, since this dimension is the optimum for the requir-
ed air speed through the filter, the sub~ect invention pro-
vides a means for reducing the distance of the individual
filter medium layers on the pure side and enlarging the dis-
tance on the dust inlet side. This arrangement proYides for
- a very substantial advantage in that with the same filter
conditions, a substantially increased storage capacity of
- the filter is obtained and the cleaning of the filters is
- made possible and even improved.
.
Other objects and features of the present inven-
tion will become apparent from the following detailed des-
cription considered in connection with the accompanying
,
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10~ 38
drawing which discloses the embodiment of the invention.
It is to be understood, however, that the drawing is de-
signed for the purpose of illustration only and not as a
definition of the limits of the invention.
In the drawing, wherein similar reference char-
acters denote similar elements throughout the several
views:
Fig. 1 is a perspective view of a mechanical fil-
ter of the invention;
Fig. 2 is an enlarged view of the dust inlet side
of the mechanical filter in accordance with the invention;
and
Fig. 3 is an enlarged view of the pure gas side of
the mechanical filter in accordance with the invention.
Fig. 1 shows an assymetrical filter in accordance
with the invention which consists of a box-like frame 1
wherein a folded filter medium 2 is inserted. The filter
medium may consis~ of filter paper, fiber glass material
or the like. Folded or pleated foils 3 and 3' are inserted
: 2b between the individual layers of filter medium 2 which
maintain the required distance betwéen the individual
layers.
The filter can now be placed into the installation
whereby dust containing air is blown onto the filter in the
direction of arrow 4 and the clean air exits from the other
side of the filter in direction of arrow 5. The dust or
the reclaimed powder is col~ected between the folds of
foils 3. In the mechanical filter in accordance with the
invention, foils 3 on the dust inlet side are provided with
~0 a large fold than foils 3' on the pure gas side. Thus,
the individual chambers on the dust inlet side are larger;.
and the distance between the layers of filter medium 2 is
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~11138
also increased. As can be seen from Fig. 3, the distance
- . -- between the individual layer's of the filter medium are'
smaller at the pure gas side which is a result of the
smaller fold of foils 3'.
Depending on the material to be separated, the
ratio between the large fold with respect to the small
fold is about 2 : 1 to 3 : 1 for the same square meter
' dimension of the mechani'cal filter ma*erial-per filter
element.
10 From the foregoing description, one skilled in
the art can easily ascertain the essential characteris-
: ' tics of this inventio,n, and without departing from the '
spirit and scope thereof, can make various changes and
modifications of the invention to adapt it to various
. usages and conditions. Consequently, such changes and
. modifications are properly, equitable, and intended to
. be, within the'full range of equivalence of the following
' . claims.
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