U.S. patent application number 13/820317 was filed with the patent office on 2013-09-05 for method for making a filter segment for a disc filter and the filter segment.
This patent application is currently assigned to VEOLIA WATER SOLUTIONS & TECHNOLOGIES SUPPORT. The applicant listed for this patent is ke Ralvert. Invention is credited to ke Ralvert.
Application Number | 20130228506 13/820317 |
Document ID | / |
Family ID | 45773141 |
Filed Date | 2013-09-05 |
United States Patent
Application |
20130228506 |
Kind Code |
A1 |
Ralvert; ke |
September 5, 2013 |
Method for Making a Filter Segment for a Disc Filter and the Filter
Segment
Abstract
A disc filter disposed around a drum for filtering water. The
disc filter includes a frame structure and a plurality of filter
segments arranged around the drum and secured to the support. Each
filter segment includes a filter frame having first and second
portions and filter material integrated with the first and second
portions of the filter frame through an injection moulding
process.
Inventors: |
Ralvert; ke; (Hassleholm,
SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ralvert; ke |
Hassleholm |
|
SE |
|
|
Assignee: |
VEOLIA WATER SOLUTIONS &
TECHNOLOGIES SUPPORT
Saint-Maurice
FR
|
Family ID: |
45773141 |
Appl. No.: |
13/820317 |
Filed: |
August 30, 2011 |
PCT Filed: |
August 30, 2011 |
PCT NO: |
PCT/SE11/51035 |
371 Date: |
May 10, 2013 |
Current U.S.
Class: |
210/331 ;
210/486; 264/257 |
Current CPC
Class: |
B29C 2045/1681 20130101;
B29K 2105/12 20130101; B29C 45/1671 20130101; B29K 2067/00
20130101; B29K 2105/0809 20130101; B29C 45/0001 20130101; B01D
33/23 20130101; B29K 2309/08 20130101; B29C 45/14262 20130101; B29K
2667/00 20130101; B29K 2023/12 20130101; B29C 55/02 20130101; B29L
2031/14 20130101; B29C 45/14336 20130101 |
Class at
Publication: |
210/331 ;
264/257; 210/486 |
International
Class: |
B01D 33/23 20060101
B01D033/23; B29C 45/14 20060101 B29C045/14 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 2, 2010 |
SE |
1050901-6 |
Claims
1-11. (canceled)
12. A method for making a disc-shaped filer segment for a disc
filter, said filter segment comprising a filter frame and a filter
material, said filter frame being adapted for a filter support of
the disc filter, characterised by an injection moulding of the
filter frame in a lower half and upper half, wherein said filter
material is stretched and during injection moulding in stretched
condition is integrated in the lower half and the upper half of the
filter frame, and wherein the filter material after injection
moulding exhibits a residual stretching of the material.
13. A method as claimed in claim 12, characterised in that the
lower half of the filter frame is injection moulded in a first
step, that the filter material is thereafter placed against the
lower half and stretched, and that the upper half of the filter
frame is injection moulded in a second step, wherein the filter
material in the second step is integrated in the lower half and the
upper half of the filter frame.
14. A method as claimed in claim 12, characterised in that the
residual stretching is more than 2 N/cm.
15. A method as claimed in claim 12, characterised in that the
filter frame exhibits a generally elongated shape, wherein at least
one reinforcement beam extends between the long sides of the filter
frame.
16. A method as claimed in claim 15, characterised in that the
reinforcement beam by injection moulding is integrated in the
filter cloth.
17. A filter segment for a disc filter, including a filter frame
and a filter material, said filter frame being adapted for a filter
support of the disc filter, characterised by an injection moulded
filter frame with a filter material integrated in stretched
condition between a lower half of the filter frame and an upper
half of the filter frame, said filter material after injection
moulding exhibiting a residual stretching of the material.
18. A filter segment as claimed in claim 17, characterised in that
the residual stretching is more than 2 N/cm.
19. A filter segment as claimed in claim 17, characterised in that
the filter frame exhibits a generally elongated shape, wherein at
least one reinforcement beam extends between the long sides of the
filter frame.
20. A filter segment as claimed in claim 17, characterised in that
the reinforcement beam by injection moulding is integrated in the
filter cloth.
21. A filter segment as claimed in claim 17, characterised in that
the filter frame consists of glass fibre reinforced
polypropylene.
22. A filter segment as claimed in claim 17, characterised in that
the filter material includes polyester.
23. A method for making a filter segment for a disc filter,
comprising: injection moulding filter material into a filter frame
to form an integrated filter frame and filter material by: i.
injection moulding a first portion of the filter frame in a first
injection moulding process; ii. stretching the filter material over
the first portion of the filter frame produced in the first
injection moulding process; and iii. subjecting the first portion
of the filter frame and the stretched filter material to a second
injection moulding process where the second injection moulding
process: (1) forms a second portion of the filter frame; and (2)
integrates the filter material into the first and second portions
of the filter frame.
24. The method of claim 23 wherein after the second injection
moulding process, the filter material exhibits a residual
stretching of the material.
25. The method of claim 24 wherein the residual stretching is more
than 2 N/cm.
26. The method of claim 23 wherein the filter frame includes an
outer parameter that extends around the filter material and wherein
the method further provides a transverse beam that extends across
opposite portions of the outer perimeter and wherein the second
injection moulding process integrates the filter material with the
transverse beam.
27. The method of claim 23 wherein the filter frame includes first
and second half sections and wherein the second injection moulding
process sandwiches the filter material between the first and second
half sections of the filter frame.
28. The method of claim 23 wherein the filter frame is constructed
of plastic material and the method includes penetrating the filter
material with the plastic material of the filter frame and fixing
the filter material to the filter frame.
29. A water filtering apparatus, comprising: a drum; a disc filter
secured around the drum for filtering water; the disc filter
including a support structure; a plurality of filter segments
arranged around the drum and supported by the filter support; and
each filter segment including a filter frame comprising first and
second sections and a filter material integrated into the first and
second sections of the filter frame.
30. The water filtering apparatus of claim 29 wherein the filter
frame includes a perimeter frame that is split into first and
second half sections.
31. The water filtering apparatus of claim 29 wherein the filter
frame is constructed of plastic material and wherein the plastic
material of the filter frame penetrates the filter material and
fixes the filter material to the filter frame.
32. The water filtering apparatus of claim 31 wherein the plastic
filter frame includes a perimeter portion and a transverse beam
extending between portions of the perimeter portion of the filter
frame and wherein the plastic material of the transverse beam
penetrates the filter material and fixes the filter material to the
transverse beam.
33. The water filtering apparatus of claim 28 wherein the filter
frame comprises glass fiber reinforced polypropylene and wherein
portions of the glass fiber reinforced polypropylene penetrates the
filter material and fixes the filter material to the glass fiber
reinforced polypropylene.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to a method and a device for
making a disc-shaped filter segment for a disc filter, said filter
segment comprising a filter frame and a filter material, said
filter frame being adapted for a filter support of the disc
filter.
BACKGROUND ART
[0002] A filter frame for a disc filter is previously known through
EP-1 872 843. The filter frame consists of a cast aluminium frame
and a filter material attached thereto by gluing. The filter
material may be a cloth of metal, textile, or plastic material,
which is mounted on the frame and pre-tensioned by hanging weights
around the cloth before it is glued to the frame. Filter frames of
stainless steel or pre-tensioned glass fibre have also previously
been used, and have then been constructed from prefabricated
profiles, which are joined together to form a filter frame. Even
though filter frames made of aluminium have reduced the number of
working operations as compared to constructing frames from
prefabricated profiles, the problem remains that a large amount of
filter material is consumed when pre-tensioning the cloth, and
additionally, the machining of the frame and gluing of the cloth
have been very time consuming.
SUMMARY OF THE INVENTION
[0003] An object of the present invention is to make a filter
frame, which is suitable for mass production with fewer and shorter
working operations for completing mounting of filter material in
the filter frame.
[0004] According to an embodiment of the invention, these and other
objects are achieved by a method for making a disc-shaped filter
segment for a disc filter, which filter segment comprises a filter
frame and a filter material, said filter frame being adapted for a
filter support of the disc filter, characterised by an injection
moulding of the filter frame in a lower half and an upper half with
a filter material placed between the lower half and the upper half,
said filter material being stretched and during injection moulding
in stretched condition being integrated in the lower half and the
upper half of the filter frame, and wherein the filter material
after injection moulding exhibits a residual stretching in the
material. In this manner, the filter frame is produced with the
filter material in place. Hence, subsequent mounting and gluing are
no longer necessary.
[0005] Suitably, the lower half of the filter fame is injection
moulded in a first step, subsequently the filter material is placed
against the lower half and stretched, and the upper half of the
filter frame is injection moulded in a second step, wherein in the
second step the filter material is integrated in the lower half and
the upper half of the filter frame. By injection moulding in two
steps, a satisfactory quality of the filter segment is ensured.
[0006] Suitably, after injection moulding, the filter material
exhibits a residual stretching of the material which is more than 2
N/cm. This residual stretching in the material is sufficient to
withstand the applicable loads on disc filters for water
treatment.
[0007] In a preferred embodiment, the filter frame exhibits a
generally elongated shape, wherein at least one reinforcement beam
extends between the long sides of the filter frame, said
reinforcement beam by injection moulding being integrated in the
filter cloth. The reinforcement beam increases the stability and
permits a higher load on the filter segment.
[0008] The invention also relates to a filter segment for a disc
filter, which comprises a filter frame and a filter material, said
filter frame being adapted for a filter support of the disc filter,
characterised by an injection moulded filter frame with a filter
material integrated in stretched condition between a lower half of
the filter frame and an upper half of the filter frame, said filter
material after injection moulding exhibiting a residual stretching
of the material. By integrating the filter material in stretched
condition, a finished product is achieved, which exhibits little
bulging of the filter material when loaded.
[0009] Suitably, the filter frame consists of glass fibre
reinforced polypropylene. This material is suitable for injection
moulding and enables a low weight of the filter frame.
[0010] Preferably, the filter material includes polyester. A filter
cloth of polyester exhibits a sufficient strength, may be
manufactured with suitable filter properties, and is possible to
integrate in the material of the filter frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention will be described in more detail with
reference to the appended schematic drawings, which by way of
example show presently preferred embodiments of the invention.
[0012] FIGS. 1a and 1b are sketches that schematically show a
filter segment for a disc filter according to the invention in a
top view and a side view, respectively.
[0013] FIG. 2 is a schematic perspective view of a disc shaped
filter element with three filter segments according to FIG. 1.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
[0014] In FIGS. 1a and 1b a disc-shaped filter segment 1 or plastic
panel for use in an existing disc filter (not shown) comprising a
filter frame 2 designed to fit in a holder (not shown) of the disc
filter is shown. The filter frame 2 has a generally elongated shape
and is here shown as an upside-down frustum of a cone, which is
intended to extend radially over a significant part of a filter
element (not shown) of a disc filter. The filter frame 2 suitably
consists of glass fibre reinforced polypropylene or other plastic
material with similar properties, and has been injection moulded
with a filter material 3 in stretched condition arranged integrated
in a plane between a lower half 4a of the filter frame 2 and an
upper half 4b of the filter frame 2. The filter material 3 includes
a polyester cloth, but may of course be made of other plastic
material or metal. The integration of the filter material 3 implies
that the plastic of the filter frame 2 during injection moulding
penetrates the cloth and fixes this to the filter frame 2, while at
the same time the cloth forms a reinforcement of the filter frame
2. The stretching of the filter material 3 may be achieved in
various ways, such as fixing the cloth just outside the mould used
for injection moulding the filter frame 2, and subsequently
extending the fixed cloth, or by using a heated cloth that shrinks
when the filter segment 1 cools after the injection moulding. Thus,
after injection moulding, the filter material 3 exhibits a residual
stretching of the material, which is more than 2 N/cm, and
preferably more than 4 N/cm. In order that the filter frame 2
should not bulge inwardly when loaded, a reinforcement beam 5
extends between the long sides 6 and 7 of the filter frame. Such a
pretensioning of the filter material 3 is important, since it is
subjected to higher pressures, e.g., during water treatment in a
disc filter as compared to similar filters used for cleaning
air.
[0015] The reinforcement beam 5 is by the injection moulding
integrated in the filter material 3, and suitably extends on both
sides of the filter material 3. The residual stretching of the
filter material 3 leads to reduced bulging of the cloth when loaded
as compared to a traditionally glued cloth. The reinforcement beams
5 will also contribute to reducing the bulging of the cloth. With
reduced bulging follows a longer working life of the cloth, since
the fatigue wear is reduced, and at the same time a reduced bulging
is necessary for allowing shorter construction length of the disc
filter.
[0016] As may be seen in FIG. 2, the filter segment 1 is intended
to be slid into said holder or in other manner be releasably
attached on each side of a filter support 8 of a disc filter 9. In
FIG. 2, three filter segments 1 are shown arranged in the filter
support 8. A plurality of disc-shaped filter segments 1 are
arranged around a central drum 10 of the disc filter 9 to form a
generally circular disc-shaped filter segment 11 on each side of
the filter support 8. The disc-shaped filter element 11 in FIG. 2
has fourteen positions for the filter segments 1, but naturally,
the number of positions may vary depending on the size of the disc
filter 9. Liquid intended to be cleaned thus flows through openings
12 in the central drum 10, and out through two filter elements 11
arranged about the filter support 8, to then pass through the
filter material 3 in the respective filter segment 1, possible
pollutants being intended to be caught in the cloth.
* * * * *