2. 01 General information
Why choose for wedge wire?
- no risk
- mechanical strength
- no maintenace cost
- no replacement cost
= less production stops
Wedge wire: less total
cost of ownership
What is
wedge wire?
Trislot® wedge wire filter elements
are made from shaped wires
referred to as profiles and other
shaped wires referred to as
support rods.
The surface profile wires are
accurately spaced and welded to the
support rods. The welding is done
by automatic resistance welding.
TESTIMONIAL
“As an Original Equipment
Manufacturer (OEM) of high
quality automatic backwash
filter equipment, we took
the decision many years ago
to shift from wire mesh to
Trislot® wedge wire screens.
The reason is obvious: take no risk protecting
expensive equipment and/or products. A lead-
customer (a steel plant) is using our equipment to
filter its cooling water. In this process, the filter ele-
ment is crucial in our equipment. It has to be very
strong and very good quality. The fragile structure
of wire mesh forced us to shift to wedge wire. In
one occasion the wire mesh filter element broke
during the working process, with big financial
losses for the steel manufacturer as a result. As the
hard-particles were no longer separated from the
cooling water for the rollers, the rollers were dam-
aged and the produced steel plates had recurrent
print marks, hence became second choice steel
plates ... You can imagine the financial loss for
my customer.
We resolved the problem permanently by using
Trislot® wedge wire screens in all our equipment
and applications. In addition to the strong
construction, the non-clogging structure of
the wedge wire screens even gives us a bigger
advantage as the filtering process does not need
to be interrupted for changing out clogged wire
mesh filter elements.
Both Korea Envi-Tech and our customers are
extremely happy with this solution.”
Mr. Jong-Ho Park
President Korea Envi-Tech, South Korea
2
3. Quality of
goods
Reliability of
delivery
Customer
support
Quality of
documentation
Pricing
Excellent
Above average
Average
Below average
Poor
Customer satisfaction questionnaire
about the quality of Trislot®
Why choose for Trislot®
?
- excellent service
- high precision
- best quality
What does
Trislot®
make?
From two basic forms, almost all
shapes and sizes can be developed
according to the customer’s wish,
namely:
- slot tubes;
- flat screens.
The filter elements can be provided
with fastenings, reinforcements ...
In most of these cases a drawing
will be submitted to the customer
for approval. After welding these
accessories to the filter elements,
further treatment can be provided
to improve the surface quality:
- degreasing and
pickling (standard);
- hardening mainly by tenifer
treatment and hard chromising;
- mechanical and electrolytical
polishing.
3
4. Trislot®
surface profiles
Figure Name Width Height α°
Cross
section - Q
Moment of
resistance - W
Bending
moment - I
Titanium
GR II
mm mm mm2
mm3
mm4
DIN 3.7035
Ø 0.8 0.8 (round) - - 0.5 0.05 0.02
Ø 1 1 (round) - - 0.785 0.098 0.049
Ø 2 2 (round) - - 3.14 0.785 0.785
4S 0.45 1.2 6 0.4003 0.0848 0.0442
5S 0.5 1.25 6 0.4760 0.1026 0.0566
6SC 0.6 1.2 13 0.5 0.071 0.051
10S 0.75 1.425 10 0.728 0.13 0.109
11S 0.75 1.8 8 0.912 0.208 0.22
12S 1 2 10 1.32 0.327 0.388 •
12SL 1 2 - 1.104 0.204 0.204
15S 1.2 2.5 10 1.97 0.605 0.899
18S 1.5 2.5 12.5 2.46 0.747 1.114
18SC 1.5 2.8 13 3.371 1.189 1.90
22S 1.8 3.7 10 4.351 1.975 4.348
28S 2.2 4.5 10 6.597 3.668 9.769
28SC 2.2 4.5 10 7.285 4.169 10.867
28ST 2.28 3.55 13 5.549 3.489 5.094
34S 2.8 5.5 10 10.18 6.991 22.721
42S 3.4 6.8 10 15.1 12.71 51.288
50S 3.4 7.5 10 15.79 13.90 63.277
50SC 3.4 7.5 12 18.529 16.361 73.38
Trislot®
support profiles
Figure Name Width Height
Cross
section - Q
Moment of
resistance - W
Bending
moment - I
AISI
430
AISI
304
mm mm mm2
mm3
mm4
DIN 1.4016 DIN 1.4301
Q 22 2 2.28 3.273 1.005 0.892
Q 25 2 3 4.61 2.019 2.39 •
Q 35 3 5 11.75 8.52 17.032 • •
Q 53 5 3 8.084 4.039 3.787 Flexible screen
D 45 3.8 5.6 13.803 9.67 22.512 Teardrop-shaped
D 56 5 6.5 22.14 17.678 50.031 Teardrop-shaped •
10 x 3 3 10 26.125 40.329 177.916 • •
11 x 5 5 11 42.92 62.96 299.7 •
12 x 3 3 12 32.02 48.848 322.14 • •
15 x 3 3 15 41.13 81.96 664.6 •
25 x 3 3 25 71.125 283.52 3366.92 •
50 x 3 3 50 145.549 1126 28859.9 •
The open area, Fo, is expressed in % and can be calculated using this formula:
Fo =
s
x 100 (%)
b + s
Example:
Surface profile 22S : b = 1.8 mm and Slot width : s = 0.5 mm
Fo =
0.5
x 100 % = 22 %
1.8 + 0.5
s = slot width (mm)
b = width of surface profile
4
5. AISI
430
AISI
304
AISI
321
AISI
316L
AISI
317LN
Uranus
B6
Monel
400 (1)
Hastelloy
C276 (2)
Uranus 45N
Duplex
Uranus 52N
SuperDuplex
254
SMO (3)
DIN 1.4016 DIN 1.4301 DIN 1.4541 DIN 1.4435 DIN 1.4439 DIN 1.4539 DIN 2.4360 DIN 2.4819 DIN 1.4462 DIN 1.4507 DIN 1.4547
• •
• •
• •
•
•
•
• • •
•
• • • • • • • • •
Diamond-shaped for support purpose •
•
• • • • • •
AISI 316 Ti; with wear-head
• • • • • • • •
• • • •
AISI 316 Ti and 1008 Si; with wear-head
• •
• • • • •
• • • • •
•
with wear-
head
•
AISI
321
AISI
316L
AISI
316Ti
AISI
317LN
Uranus
B6
Monel
400 (1)
Hastelloy
C276 (2)
Uranus 45N
Duplex
Uranus 52N
SuperDuplex
254
SMO (3)
DIN 1.4541 DIN 1.4435 DIN 1.4571 DIN 1.4439 DIN 1.4539 DIN 2.4360 DIN 2.4819 DIN 1.4462 DIN 1.4507 DIN 1.4547
•
• • • • • • • •
• • • • • • •
•
•
• • • •
• •
• •
• •
(1) Registered trademark of Inco Alloys.
(2) Registered trademark of Haynes International.
(3) Registered trademark of Avesta Sheffield AB.
•• Standard available on stock
•• Available for projects
5
6. 02 Trislot®
slot tubes
What are slot
tubes?
Trislot® slot tubes are composed
of a surface profile that is spirally
wrapped around axial support pro-
files and attached to eachother by
resistance welding. These filter
elements have the unique advan-
tages of very accurate, narrow slot
openings and perfect roundness all
in one.
Slot tubes can be provided with
the necessary endpieces for
attachments and/or reinforcements.
Slot tube
Filtering
Backwashing
Filter cycle
During the filter cycle, the solids are
deposited on the smooth surface.
This ‘cake’ acts as an extra filter for
finer particles. The fines that slip
through do not get stuck in the
conical slots.
Backwash cycle
By reversing the flow, the cake and
dirt are removed from the filter
surface.
Filter cycles
6
7. Standard constructions(1)
(1) Special constructions are possible on request.
(2) Each diameter requires new welding equipment. Therefore the standard diameters shown in the next table, are preferred.
(3) The minimum slot will increase when the diameter becomes bigger. Other diameters than these standards are available on request.
(4) depending on the slot tube diameter.
Profile Support wires Min. Ø(2)
Min. slot width(3)
in mm in mm
4S Q22 or Q25 20 0.015(4)
5S Q22 or Q25 20 0.015(4)
6SC Q22 20 0.015(4)
10S Q25 20 0.015(4)
11S Q20 or Q25 21 0.015(4)
12S Q25 21 0.015(4)
Q35 30 0.05
18S 22S or Q35 30 0.05
Q25 25 0.03
D45 300 0.2
10x3 300 0.2
22S 22S or Q35 45 0.05
D45 or 10x3 or 25x3 300 0.2
28S Q35 215 0.2
D45 or 10x3 or 25x3 300 0.2
34S Q35 300 0.2
D45 300 0.2
10x3 or 25x3 300 0.2
42S Q35 or D45 300 0.2
10x3 or 25x3 300 0.2
O.D.
Number of
support profiles
in mm
30 8
45 10
57 12
70 18
85 18
97 20
110 24
137 30
164 36
215 48
268 48
305 40
380 48
460 60
510 64
628 80
914 180
TESTIMONIAL
“Trislot® has offered
valuable design input,
high quality products,
and on-time deliveries for
PSL for many years. Trislot’s flexible approach
to design, excellent technical knowledge
and customer focus has forged a valuable
partnership between Trislot® and PSL in the
pharmaceutical marketplace.”
PSL
Powder Systems Limited, UK
TESTIMONIAL
“We have been trading
partners with Trislot for
many years now, and
we hope our partnership can
last for many years more.
The service and quality we
demand would be absolutely
unattainable elsewhere.
Trislot always provides us with the best answer,
even when faced with those ‘unplanned’
moments.”
Allen Moss
Russell Finex Ltd, UK
7
8. Special features
Inverted profiles
Inverted profile, for filtration in to
out with support profiles at the
inside, is possible for most profile
combinations.
Variable slotopening is possible for
slot tubes with outside diameter
up to 914 mm.
Continuous cylinders
By using a lot of support profiles,
an axial slot can be obtained. These
filter elements are called continuous
cylinders. The minimum slot width
is 0.1 mm.
Reinforced slot tubes
Reinforcing the slot tubes is
possible through:
- more or stronger support profiles;
- reinforcement spiral;
- reinforcement cross;
- perforated reinforcement tube,
used as distributor of the fluid
over the slot tube.
Reinforcement cross Perforated reinforcement tubeReinforcement spiral
Inverted profile
Continuous cylinder
8
10. Finishing touch
of the end surfaces
Standard
- grinding end surfaces
- remove the loose profile ends
- degreasing and pickling
Optional
- fasten loose profile ends
- remove the burrs of
the profile ends
- post machining for
tighter tolerances
Endpieces
Standard endpieces are always
welded onto the support profiles.
Threaded fitting
Flange Welding ring and threaded fitting
Welding ring and closure plate
Endring
Resistance welded closure plate
Support elements
If the slot tubes are used as a car-
rier for another filtermedium for
example textile, round wire can be
applied. These support elements can
be welded with 1, 2 or 3 wires next
to each other.
Technical information
- diameter: ± 25 to 40 mm
- standard profiles:
spiral wire: ø 0.8 mm
support wire: ø 2 mm
Support element
10
11. Standard constructions (1)
(1) Special executions are possible on request
(2) In most cases, all pitches are possible
What are
welded screens?
Trislot®
welded screens are directly
produced as flat screens. This avoids
the chance of stress corrosion
and the weakening of the welds,
which does occur with opening
and flattening slot tubes (this is
the normal way to manufacture
flat screens).
For special applications,
welded screens can be made out
of slot tube. The Trislot®
welded
screens are available in very light
constructions (11S/Q25) as well as
more robust forms (50S/50x3) and
can be provided with the necessary
frame and/or reinforcements.
03 Trislot®
welded screens
Max. surface profile length Max. support profile length
Pitch 17 mm/Profile Q25 810 mm 2000 mm
Pitch 17-25 mm/Profile Q35 2700 mm 3000 mm
Pitch 22 mm 710 mm 1700 mm
Pitch ≥ 70 mm 3000 mm (3)
3500 mm
Profile Support wires Min. slot Standard pitch (P)
in mm in mm(2)
11S Q25 0.03 17/22
12S Q25/Q35 0.03 17/22
10x3 0.1 17/25
18S Q35 0.05 17/25
Q35/10x3/25x3 0.1 25/70
22S Q35 0.05 17/25
Q35/10x3 till 50x3 0.12 25/70
28S Q35/10x3 till 50x3 0.15 17/25/70
34S Q35/10x3 till 50x3 0.15 17/25/70
42S Q35/10x3 till 50x3 0.15 17/25/70
50S 10x3 till 50x3 0.15 70
(3) Depending on pitch
Maximum dimensions
11
12. Different support profiles
A combination of different support
profiles and pitches within one flat
screen is possible.
Special requests
Frames and reinforcements can be
designed and calculated on request,
provided that we know the tem-
perature, supports and differential
pressure (∆P).
Conical baskets and cylinders
Cylinders and conical baskets
(conical shape) are manufactured
out of one or more flat screens that
are rolled and welded. Slot tubes can
be used as well for this purpose
after opening and flattening the
elements.
Conical basket
Special constructions
12
13. Cylinder
Reverse rolled
slot tube
Cylinders
The standard construction is as
follows : slot direction is axial and
the filtration direction is from the
inside towards the outside. Smooth
surface is at the inside and support
profiles are at the outside.
Technical information
- minimum cylinder diameter
= 25 mm depending on the profile
combination and construction;
- maximum diameter = unlimited;
- slotopening: see flat screens,
slot tubes.
Reverse rolled slot tubes
When a scraper blade is used, it is
required that the supports are at
the outside and the slots are radial.
This is called a reverse rolled
slot tube.
Technical information
- minimum cylinder diameter
= 100 mm depending on profile,
length and material;
- maximum diameter = unlimited;
- slotopening: see slot tubes.
TESTIMONIAL
“Recently we had a very large international
project with a tight and strict schedule.
Together with Trislot, we developed the
supply plan to meet the project requirements.
During production, we had another very good
customer submit an emergency Purchase Order
which also required the high quality level of Trislot
filter elements. Trislot immediately reacted and
together we achieved the required delivery of
both projects. MAHLE Industrial Filtration sincerely
appreciates our relationship and the customer
service of this premium quality supplier.”
Darren Morgan
MAHLE Industrial Filtration USA, Inc.
Vice President (Operations)
13
14. 04 Applications
Trislot®
welded screens can be used
as flat filters or processed
to make cylinders.
Flat screens
- static sieves for dewatering or
classification: the screen is set
up at a certain angle or is curved
so that the surface profiles are
perpendicular to the filtration
direction. Through gravitation the
slurry flows over the screen.
- vibrating screens, dryers and
coolers: screens used as support
for the product that has to be
treated
- band filters: screen as support for
paper or textile, for example for
the separation of cutting oil
- support screens: in this
application, the screens are
assembled inside vessels to
support catalyst, active carbon,
resin, molecular sieve ...
- beer bottoms
Cylinders and baskets
- drum screen with or without
internal transport screw
- centrifuge baskets and cylinders
for the food and paper and pulp
industry
- starch screens
- screw presses
Support screen
Beer bottom
Heavy continuous cylinder
for screw presses
Curved screens
Curve direction and filtration
direction are to be determined by
the customer.
14
