|
absolute
micron retention
|
In both types of Dutch weave the
sum derived from multiplying the number of weft wires in a given
measurement by their diameter, results, in theory, in a specification
with no open space. Because the wires are driven together during
the weaving process, the aperture size cannot be calculated
in the normal manner.
There are two methods by which
the aperture size can be determined: bubble point testing
and glass bead testing.
See-"bubble
point test" See-"glass bead test"
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|
ACS
|
American Chemical Society.
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|
AICHE
|
American Institute of Chemical
Engineers
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AIME
|
American Institute of Mining,
Metallurgical and Petroleum Engineers.
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anneal
|
A heat-treating process in which
the steel is heated to some elevated temperature, usually at
or near the critical range and held at this temperature for
a period of time, then cooled, usually at a slow rate.
Annealing is employed (1) to
soften steel for secondary machining or forming processes;
(2) to alter ductility, toughness, electrical or magnetic
characteristics or other physical properties; (3) to refine
the crystal structure; (4) to produce grain reorientation;
or (5) to relieve stresses and hardness resulting from weaving
(cold working).
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annealed after
|
Wire cloth or wire mesh which
is annealed after the weaving process.
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|
annealed wire
|
Wire which has been cold-drawn
to reduce its diameter is often annealed to reduce strength
and increase elongation to facilitate weaving.
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|
ANSI
|
American National Standards Institute.
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|
aperture
|
The clear opening between wires
on a wire mesh screening surface.
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ASME
|
American Society of Mechanical
Engineers.
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|
ASTM
|
American Society for Testing and
Materials.
ASTM E-11 is the standard most
widely used in North America. The opening is defined by a
number (number 635 (20 µm) to number 3-1/2 (5.6 mm)) or is
defined in inches (1/4 in. (6.3 mm) to 5 in. (125 mm)).
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AWCI
|
American Wire Cloth Institute.
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A.W.G.
|
American Standard Wire Gauge.
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AWS
|
American Welding Society.
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backing cloth
|
Wire mesh or wire cloth which
is utilised to provide support for a screen surface.
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backing screen
|
Wire mesh or wire cloth fabricated
with or otherwise fastened to (from below) the primary screen
surface. See-"support screen".
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ball screen
|
Wire mesh or wire cloth screen
placed below the primary screen surface to retain rubber or
steel balls or plastic discs which are set in motion by a vibrating
screen deck.
Ball screens are utilised to
reduce or prevent blinding or plugging.
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blinding
|
Filling in and clogging of the
wire mesh openings (apertures) due to particle entrapment of
the process material. The wire cloth becomes "blind"
to the process flow.
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BMT
|
Abbreviation for "Broad Mesh
Twilled Dutch Weave"
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|
Bolting Cloth
|
A group of industrial wire cloth
specifications, woven in very smooth and durable stainless steel
or monel in a plain square mesh pattern. Wire diameter is lighter
than "mill grade", allowing a high percentage of open
area. Bolting cloth is used for wet or dry sifting and separating.
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bran duster cloth
|
Plain weave steel wire cloth of
medium mesh sizes produced in market grade diameters. Available
in in roll widths of 24", 30", 36" and 48"
for use in flour mills.
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broadmesh
|
In broad mesh specifications the
warp wire is typically smaller in diameter than the weft wire.
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BSI
|
British Standardisation Institute
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bubble
point test
|
The pressure required to pass
air bubbles through the mesh (covered by a test liquid) is measured.
The average aperture size is then calculated by taking into
account surface tension, liquid density, temperature and immersion
depth.
See- "absolute micron retention" See-
"glass bead test"
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|
B.W.G.
|
Birmingham Wire Gauge.
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|
calendered wire cloth
|
Wire cloth that has been passed
through a set of heavy rollers to reduce the thickness of the
cloth or to flatten the wires at weave intersections providing
a smooth surface.
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Centrisieve
|
Rotating conical screen
typical with a 125 micron screening
plate in stainless steel or a finer steel cloth.
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clear opening
|
The space
(aperture) between adjacent parallel
wires
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coarse mesh
|
Wire cloth having a mesh count
of 30 x 30 or less.
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count
|
The number of openings (apertures)
in a lineal inch.See- "mesh".
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cyclone screener
|
Cylindrical stationary sieve with
rotating paddles flinging the fines through the screen, while
the overs leaves the cylinder opposite the inlet.
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dewatering
|
Separation of solids from liquids
in which the solids are retained on the screen surface while
the liquids pass through the screen (wire mesh or wire cloth)
surface.
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DIN
|
German Institute for Standardisation
|
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DTW
|
Abbreviation for "Dutch Twilled
Weave".
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Duplex Weave
|
This specification is similar
to a Plain Dutch Weave except that two warp wires are used,
rather than one.
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Dutch Weave
|
Wire mesh or filter cloth with
warp wires larger than the shute wires. Warp wires remain straight
while adjacent shute wires slightly overlap, resulting in a
dense, strong material with small irregular, twisting passages
that appear triangular in shape when viewing the material diagonally.
Dutch weaves have much lower
flow rates and much higher particle retention than plain square
weaves.
See - "Hollander
Weave"
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|
filter
|
A device utilising filter media
for particle retention for clarification of a liquid or gaseous
fluids.
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|
filter cloth
|
Wire or synthetic cloth woven
with a greater number of wires in one direction than the other,
and utilising two different wire diameters. Filter cloth is
woven in both plain and twill weave patterns. Also referred
to as "Dutch Weave".
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filtration
|
The process of clarifying a fluid
or gaseous liquid by the removal (retention) of solid particles
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fine mesh
|
Wire cloth having a mesh count
greater than 90 x 90
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fines
|
The product passing the sieve.
The overs is retained on the sieve.
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|
flat belt vacuum filter
|
Horizontal filter with a filter
cloth moving discontinuously across a vacuum zone
|
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flooding
|
The effect created when the screen
surface is unable to pass fluids through, in wet screening operations
such as washing or dewatering., a result of blinding
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Gauge
|
A term referring to the measure
of wire diameter. The Washburn & Moen Gauge is the standard
in the manufacture of wire cloth in North America
|
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glass
bead test
|
A suspension containing glass
beads is passed through the mesh - the diameter of the largest
bead passing through is considered as the absolute micron retention.
See - "bubble point test"
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|
Grizzly Screen
|
Heavy screen cloth usually having
a large opening size and made from large diameter high carbon
or oil tempered wire or rod.
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hard wire
|
Wire which has been drawn down
to a smaller diameter after the annealing process, increasing
its unit strength and reducing its elongation.
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Hardware Cloth
|
A square mesh, general purpose
galvanised-after plain weave wire cloth.. Made in one wire size
only, one for each of several standard meshes.
Hardware Cloth is also available
in welded construction.
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|
Harp Screen
|
Screen cloth with long slots,
typically 12 inches or longer, for screening high volume tonnage
containing a large amount of fines
|
|
Hollander
Weave
|
A description applied to woven
wire cloth where the diameter of the warp and weft wires, and
the mesh count in the warp and weft directions, are different.
The wires are driven up much closer during the weaving process,
thus producing a more densely compacted weave with small aperture
sizes, without reducing the overall cloth thickness. Also referred
to as "Dutch Weave".
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|
HP
|
Hollander Plain Weave.
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HT
|
Hollander Twill Weave.
|
|
Hydrocyclone
|
A liquid-solids separation device
utilising centrifugal force for settling.
|
|
ICW
|
Inside clamping width
|
|
IWWA
|
International Wire Weavers Association
|
|
inside dimension
|
(ID) The distance measured between
the inner edges of a formed screen panel. Also referred to as
"ICW"
|
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ISO
|
The International Organisation
for Standardisation is a worldwide federation of national standards
bodies (ISO member bodies).
ISO 4782 standard governs metal
wire for industrial wire screens and woven wire cloth.
ISO 9044 standard governs industrial
wire cloth.
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|
KPZ
|
Reverse Hollander Twill Weave.
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long slot
|
See - "slotted
openings"
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|
Market Grade
|
A group of industrial wire cloth
specifications suitable for general purpose screening applications,
made of high strength square mesh cloth, available in several
types of material. The wire diameters are moderately larger
than "mill grade" , with a lower percentage of open
area.
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medium mesh
|
Wire cloth having a mesh count
of 30 x 30 to 90 x 90 inclusive
|
|
mesh no.
|
This generally denotes the number
of apertures in a length of 25.4mm (1"). While it is considered
an obsolete designation, it is used extensively.
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|
mesh
|
Mesh designates the number of
openings and fractional parts of an opening, per lineal inch.
Mesh is determined by counting the number of openings from the
centre of any wire to the centre of a parallel wire, one inch
in distance.
When the point one inch distant
from the centre of a wire falls between wires within an opening,
the mesh count is expressed as a fraction.
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|
micron
|
One micron is equivalent to 0.001mm
or 0.00003937 inches. The micron is the unit of measure in the
metric system. It is frequently used when referring to the aperture
size or particle-retention of filter cloth.
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|
micron retention
|
Micron retention is defined as
the diameter of the largest round particles which can pass through
a filter.
|
|
Micronic grades
|
Finer mesh range of Dutch Weave
cloth in meshes giving retention of 50 microns or finer.
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|
Mill Grade
|
Group of industrial wire cloth
specifications with lighter wire diameters than "market
grade". Standard wire diameters of this grade produce a
medium percentage of open area.
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Mud Screen
|
A wire cloth screen panel fitted
with hooks for tensioning installed on shale shakers.
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|
non-ferrous alloys
|
Non-pure metals containing no
iron, such as copper, brass, aluminium, etc
|
|
OCW
|
Outside clamping width
|
|
off count
|
A mesh which has a greater number
of wires per inch in one direction, usually the warp direction.
|
|
open area
|
The ratio of open space area between
the wires, to the total area of a given section of wire cloth,
expressed as a percentage.
Open area % = (1-N*D)2
* 100, where N = Wires per inch or mesh and D = Wire diameter
|
|
opening
|
The dimension between adjacent
parallel wires, usually expressed in decimal parts of an inch.
Opening size = (1-(N*D))/N
where N = Wires per inch or mesh and D = Wire diameter
See - "aperture"
See - "space"
|
|
outside clamping width
|
Outside dimension (overall) of
hooked edges on a screen panel. Also referred to as "OCW".Most
original equipment manufacturers recommend an OCW of 1"
less than the clear clamping width between the vibrator side
plates.
|
|
outside dimension
|
The distance between the outside
edges of a formed screen panel
|
|
overs
|
The product retained on the sieve.
The fines is passing the sieve.
|
|
particle retention
|
The particle size that will be
retained by a given mesh, usually expressed in microns.
|
|
pitch
|
The distance between centres of
two adjacent wires in millimetres.
|
|
pitting corrosion
|
Localised corrosion resulting
in small pits or craters in a metal surface.
|
|
Plain Weave
|
Woven wire cloth in which each
warp and each weft wire passes over one and under the next adjacent
wire in both directions.
|
|
Plain Dutch Weave
|
Dutch weave with each warp and
shoot wire passing alternately over and under each successive
wire.
|
|
plate,
screening
|
Screening plate is a thin stainless
steel with etched perforation - preferably made as a profile
screen with conical perforations.
|
|
plugging
|
Near size particles trapped in
screen apertures (openings) preventing passage of under size
particles. See - "blinding"
|
|
porosity
|
The fractional void volume of
the mesh.
|
|
profile wire
|
Wire that has been drawn into
a "wedge" (tapered) shape, which becomes progressively
narrower from top to bottom.
|
|
Profile
Screen
|
A screen panel made up of profile
wires with openings that become progressively wider from top
to bottom. This increases dewatering efficiency and aids in
screening material which might otherwise blind a screen surface.
Also referred to as "wedge wire screen".
|
|
PZ
|
Reverse Hollander Plain Weave.
|
|
rectangular mesh
|
Wire cloth having a different
number of wires in the warp and shoot (shute) usually less in
the shoot, producing rectangular openings. See - "off
count".
|
|
retention
|
The ability of wire cloth (wire
mesh), as a filter medium, to prevent the passage of solids.
It is expressed by the diameter, usually in microns, of the
largest spherical solid particle that will normally pass through
the screening surface.
|
|
RPD
|
Abbreviation for "Reverse
Plain Dutch Weave".
|
|
Reverse Plain Dutch Weave
|
The arrangement of the warp and
shute wire is reversed as compared to Plain Dutch Weave, providing
a higher mesh count in the warp direction rather than the weft
(shute) direction.
|
|
Rotary Screen
|
See - "trommel
screen".
|
|
Rotary vacuum filter
|
Trommel
with filter cloth and support rotating in a tray with product
product. The product built up a pre-coat and the filtered product
is cut off the rotating drum by a knife and the water is drawn
to the interior of the filter drum by a vacuum.
|
|
RotoSieve
|
Rotary screen
|
|
sieve
|
Metric openings, in a fixed ratio,
assigned by the U.S. Bureau of Standards, based upon the number
18 sieve having an opening on one millimetre (0.039370").
The relation of consecutive
numbered sieves is as one to the fourth root of two (or for
every fourth sieve ratio is as one to two). Sieve numbers
are arbitrary numbers and have no direct relationship to the
number of meshes per inch.
|
|
slotted
openings
|
Wire cloth (wire mesh) with rectangular
openings which allows the maximum open area and tends to prevent
blinding or plugging of material.
The warp mesh-count and wire
size are indicated before the shoot (weft) mesh- count and
wire size.
|
|
space
|
The actual clear opening or space
between the inside edges of two parallel wires.
|
|
Space Cloth
|
Square mesh wire cloth which is
designated by the width of the open space between the inside
edges of two parallel wires.
|
|
SPW
|
Abbreviation for "Single
Plain Dutch Weave".
|
|
square mesh
|
Wire cloth with the mesh count
and wire diameter the same in both directions.
|
|
stranded weave
|
A twilled weave with multiple
wires in both warp and the weft.
|
|
strainer
|
A fabricated assembly of woven
wire cloth (wire mesh) designed for the removal of foreign particles
from a stream of liquid or gas.
|
|
strainer cloth
|
A plain weave off-count mesh cloth
with a high percentage of open area.
|
|
support
screen
|
A heavy wire mesh utilised to
support a finer mesh in filtration or straining.
|
|
S.W.G
|
British Imperial Standard Wire
Gauge.
|
|
Testing Sieve
|
Fabricated circular frames available
in stainless steel, brass or plastic fitted with wire mesh woven
of brass, phosphor-bronze or stainless steel, having extremely
accurate openings. Sieves are produced according to various
standards, in the U.S. typically per ASTM E-11-70 in Europe
according to DIN
|
|
Tinned Cloth
|
Wire cloth (wire mesh) woven of
wire that has been coated with tin before the weaving process.
Tinned cloth is generally available in "mill
grade" wire diameters.
|
|
TRD
|
Abbreviation for "Twilled
Reverse Dutch Weave"
|
|
Trommel
Screen
|
A screen panel which is rolled
to cover a cylinder, typically fastened by bolts, clamps or
straps
|
|
Tyler
|
The W.S.Tyler Company, Cleveland
Ohio.The Tyler company is the North American leader for Analytical
Sieves of all sizes.Tyler had already standardized their sieves
before ASTM, so in some cases, the Tyler number might be different
than the ASTM number.
|
|
Twill Weave
|
Woven wire cloth in which each
weft wire passes successively over two and under two warp wires
and each warp wire passes successively over and under two weft
wires.
|
|
Twill Dutch Weave
|
Each warp wire and each weft wire
passes over and under the next to adjacent complementary wires,
as in a normal "twill weave", except the warp wires
are larger in diameter than the weft wires. This allows a greater
mesh count in the weft direction.
This weave pattern enables
the weft wires to be woven more densely, and much smaller
aperture sizes can be achieved.
|
|
warp
|
The wires running lengthways during
weaving are referred to as WARP wires.
|
|
weft
|
The wires that run across the
width of the cloth are referred to as WEFT or shoot wires.
|
|
wire
|
A solid wrought product that is
long in relation to its cross section, which is square or rectangular
with sharp or rounded corners or edges, or is round, a regular
hexagon or a regular octagon, and whose diameter or greatest
perpendicular distance between parallel faces (except for flattened
wire) is less than 0.375 inch
|
|
wire cloth
|
A general term for material woven
from metallic wires.
|
|
wire diameter
|
The diameter of wire before weaving.
|
