Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to the scouring of elonga-te material
and in par-ticular to the cleaning or abrasion of the surface of
rod or wire~
It is of-ten necessary in the manufacture of wire for the
surface to be cleaned; for example to remove a coating of oxide
following a heat treatment, or a coating of lubricant following
a rolling or drawing operation.
Conventional techniques of cleaning wire generally involve
immersing the wire in one or more baths of solvent, strong acid or
alkali. These techniques have the disadvantage that the chemicals
in such baths are usually dangerous and corrosive and must them-
selves be removed from the wire after the treatment by rinsing the
wire in a further bath. Other practical problems a tend such
treatments; for example the chemicals used often act relatively
slowly and thus the wire must spend a long time in the bath. In
order to achieve an economical rate of processing a long length of
wire must be in the bath at any one time necessitating a large bath.
This problem can be solved by immersing the wire in coil form but
the cleaning is not always satisfactory because the chemical does
not penetrate adequately to all the layers of wire on the coil.
An object of this invention is to provide surface treat-
ment of elongate material, for example rod or wire, in which at
least to some extent the problems outlined above are alleviated.
According to a first aspect of the present invention there
is provided a device for scouring the surface of elongate material
including a primary generally cylindrical chamber having at least
one substantially tangentially directed inlet for fluid and a pair
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of secondary generally cylindrical chambers which are axially
aligned with, and respectively on opposite sides of the primary
chamber, and each having a substantially smaller radius than the
primary chamber, the primary and secondary chambers being arranged
to allow elongate material to be passed axially through them and
the secondary chambers forming outlets for fluid from the primary
chamber, the arrangement being such that when the device is in use
fluid forced into the primary chamber via the inlet forms a ro-
tating body of fluid in the chambers, the angular velocity of which
so increases as the radius of rotation decreases when the fluia
passes in opposite directions relative to the length of the material
into the respective secondary chambers that the elongate material
is scoured and the fluid escapes from said secondary chambers.
According to a second aspect of the present invention one
or more devices are arranged in a first treatment zone, spaced from
a second treatment zone also containing one or more devices, said
devices of the first and second treatment zones being aligned so
as to allow elongate material to pass a~ially freely through the
devices when the apparatus is in use, means for conducting a
first fluid to the inlet for fluid of each device in the first
treatment zone, means for conducting a second fluid to the inlet
for fluid of each device in the second treatment zone, and means
for directing air or other gas into a region between the first
treatment zone and the second treatment zone, so as to prevent the
first and second fluids from coming into contact with each other.
The invention also consists in a method of scouring
elongate material.
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By way of example only an embodiment of the present
invention suitable for cleaning the surface of wire will now be
described making reference to the accompanying drawin~ in which:
FIGURE 1 is a sectional elevation of a cleaning apparatus
taken on the line s-B in Figure 2;
FIGURE 2 is a cross-section on the line A-A in Figure l;
and
FIGURE 3 is an enlarged section view of one of the
cleaning heads of the apparatus of Figures 1 and 2.
Referrlng to Figures 1 and 2, a wire 50 is cleaned by being
passed under tension, typically 35 lbs (15.9 kg) for a 2 mm carbon
steel wire of tensile strength 70 tons/sq. in (11 tonne/sq. cm.)
continuously through cleaning apparatus 51. The apparatus 51
consists of a block of metal 1 with a central bore 2, typically of
diameter 7/8 in. (2.2 cm) running the full length oE the block.
In the central bore 2 are eight cleaning heads 13-20 arranged in
two groups, a group of two 13, 14, and a group of six 15-20.
These groups are separated by a central drying head 22. Drying
heads 21, 23 are provided at ends of the bore 2. The cleaning
heads 15-20 and the central drying head 22 are held in place by
screws lA in the upper face of -the block 1. The drying heads 21,
23 are themselves threaded and screw into a threaded end portion
of the bore 2 to tighten down onto "O" rings 21C, 23C which form
a seal.
Also running the full length of the block 1 is a narrower
bore 3, typically of diameter 1/2 in. (13 mm), which has an inlet
10 for connection to a compressed air line. Leading from the
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narrower bore 3 are passageways 25 leading to each of the drying
heads 21-23.
The block 1 also has two blind bores 4 and 5 drilled from
opposi-te ends of the block and running alongside the bore 1. Each
of -these bores 4 and 5 is connected to a respective inlet port 9,
8 for the working fluid. The bore 4 connects to passageways 24
which in turn feed the first group of cleaning heads 15-20.
Similarly bore 5 feeds the group of two cleaning head 13, 14. The
blind bores 4 and 5 and the bore for compressed air 3 are plugged
at the end of the block 1 by plugs 4A, 5A and 3A respectively.
In the underside of the block 1 is a milled exhaust slot
2A designed to allow the working fluid from the cleaning heads to
escape into exhaust tanks below. One of these tanks is denoted in
Figure 2 by the re~erence numeral 80. In the base of each exhaust
tank is a cylindrical outlet 81 with a threaded connector 81A.
Each of the drying heads 21, 22 and 23 consists of a
central bore ~shown as 21_ on the drying head 21) and at least one
diagonal passage (shown as 21_ on the drying head 21). High pres-
sure air is fed from the narrower bore 3 in the block 1 via the
passage 25 to the diagonal passage 21b where i-t impinges on the
wire 50. Operation of the drying heads is as described and claimed
in Patent Great Britain 1 533 846.
In operation each of the inlet ports 8 and 9 is supplied
with working fluid at a pressure of typically 250 p.s.i. (730 kg/
sq. cm.) from pumps. The working fluid supplied to the group of
six cleaning heads 15-20 is typically a dilute alkali, an organic
solvent or water and the working fluid supplied to the group of two
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cleaning heads 13 and 1~ is typically water. Compressed air is
supplied, typically at 100 p.soi. (292 kg/sq. cm.) to the inlet 10
-to feed the drying heads. Instead of compressed air, another gas,
e.g. nitrogen, may be used if the surface of the wire needs to be
protected from air.
Tracing now the passage of wire through the c:Leaning
apparatus, it first encounters drying head 230 The primary function
of this head is to prevent leakage of the working fluid out of the
apparatus back along the wire. Next the wire passes in turn
through each head of the group of six heads 20-15, where it is
cleaned.
This action is described in detail below with reference
to Figure 3. The wire then enters the drying head 22 which has
two angled air jets 22A and 22B. The jet 22B serves to prevent
the working fluid from the group of ~ix heads 15-20 from travelling
forward along the wire, and the jet 22A prevents the working fluid
from the group of two heads 13, 14 from travelling back along the
wire. Fffectively then, the drying head 22 provides a cushion of
air which separates the two working fluids. With suitable adjust-
ment of the air pressure with respect to the pressure of theworking fluids ensures that they are kept apart. This separation
of the working fluids is particularly useful as it enables the
two groups of heads to be used for two different operations. In
this embodiment the group of six heads 15-20 are used to clean
the wire 50 and the group of two heads 13, 14 for rinsing it. The
cleaning may be the removal of an oxide coating and use an alkali
and the rinsing may be to remove all traces of alkali After
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passing through the drying head 22A the wire passes -through the
two cleaning heads 14 and 13.
These two heads 13 and 14 serve to rinse the wire~ ensuring
the removal of all traces of the working fluid used in group of
six cleaning heads 15-20 and any products formed by its action.
Finally the wire passes out of the apparatus through the drying head
21 which ensures that none of the rinsing fluid used in the group
of two cleaning heads 13-14 travels forward along the wire. The
wire leaves the apparatus completely dry.
As previously mentioned the working fluids used in the
cleaning heads pass into two tanks, one for each group of heads.
In the case of the group of two heads 13-14 where the working fluid
used is water it may be recycled or passed to waste v~a an exhaust
outlet (not shown). In the case of the group of six heads 15-20
provision is made to recycle the working fluid. From the exhaust
outlet 81 it passes to a storage tank (not shown) and is eventually
fed back to the pump supplying the inlet port 9. The storage tank
may be remote from the cleaning apparatus.
The construction and operation of one of the cleaning
heads, for example the head 17 will now be described with reference
-to Figure 3. The cleaning head 17 consists of a cylindrical tube
70 machined to locate two annular end pieces 71. Each of these end
pieces 71 is an interference fit in the tube 70 which is shrunk
onto them when the head is being assembled. Each end piece has a
shouldered bush 75 which is an interference fit in a suitably
profiled hole in the end piece 71.
The material out of which the bush 75 is made depends on
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the application. If it is required to clean finished wire, for
example to remove the lubricant used in the drawing process, a
soft tough material such as ultra-high density polyethylene or
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Tufnol may be used. This gives a high quality smooth finish. If,
on the other hand a fierce abrasive action is required and the
surface finish is less important tungsten carbide may be used.
The tube 70 and the end pieces 71 together define a
primary generally cylindrical chamber 72. The hole in the centre
of each bush 75 forms a second generally cylindrical chamber and
has a diameter which is substantially smaller than that of the
primary chamber. For example the primary chamber may be 7/8 in.
o.d. (22 mm). The diameter of the secondary chamber depends on
- the size of the wire cleaned and may typically be 1/16 in. (1.5 mm)
for up to 50 Thou (1.27 mm) wire, 1/8 in. (3 mm) for up to 0.1 in.
(2.5 mm) or 1/4 in. (6.35 mm) for 5.5 mm rod. The inlet for the
working fluid is a hole 74 which is substantially tangentially to
the curved wall of the primary chamber 72. The orientation of
this hole can be seen more clearly in Figure 2.
In operation the working fluid is forced into the primary
chamber via the hole 74. Because the fluid enters the primary
chamber substantially tangentially it circulates in the chamber
at an angular velocity defined by the linear velocity at which it
enters. Exit is only possible via one of the secondary chambers
73 around the wire 50. The principle of conservation of angular
momentum dictates that the angular momentum of the fluid as it
flows through -the secondary chamber 73 must be substantially equal
to the angular momentum of the fluid while it is in the primary
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chamber. As the diameter of the secondary chamber is less thanthat of the primary chamber the angular velocity of the fluid in
the secondary chambers must be proportionally greater than that
of the fluid in the primary chamber for the angular momentum to
be conserved. By suitably arranging the pressure of the working
fluid supplied to the apparatus and the ratio of diameters of the
chambers the angular velocity of the fluid in the secondary chamber
can be made so high that a vibration is set up in and around the
wire which causes the surface of the wire to be abraded.
The exact mechanism of the abrasion is not fully under-
stood but it is believed that the wire vibrates transversely within
the cleaning head in a generally circular motion, and as it does
so rubs against the walls of the secondary chambers. The
frequency of vibration is dependent at least on the distance be~
tween the two secondary chambers of the cleaning head and the
tension in the wire. It has also been found that it is not
necessary to supply fluid to all of the cleaning heads, as the
vibration set up by one head is propagated down the wire to a
certain extent and can cause abrasion to take place in an ad-
jacent non-operational head. Accordingly it is possible to re-
place some of the heads of a multi-head cleaner by dies. The
construction of the die could be similar to that of the end piece
71 of the heads. A suitable construction of cleaning apparatus
involving this modification would be achieved by replacing each
of the heads 16-19 shown in Figure 1 by dies, but leave the
remaining heads in place.
To obtain particular abrading characteristics it is
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envisaged that the inside surface of the end piece 71 of the heads
be contoured. It may for example be radiused to give a better
surface finish.
It must be appreciated that as the cleaning or abrading
action of the apparatus is due to mechanical ac-tion it is rarely
necessary to use any working fluid stronger than water, dilute
alkali or an organic solvent. The apparatus is particularly
suitable for continuous cleaning of wire and speeds of over 300
metres per minute can be achieved. A device ~o keep the wire
under a controlled tension should be provided for most efficient
operation of the apparatus, as should guides to ensure that the
wire passes centrally through the apparatus. The fluids should
be exhausted rapidly so that the spaces around the outer ends
of the secondary chambers do no fill up with fluid. In practice
the heads may be longer than those shown in Figure 1 with a
length to diameter ratio of typically 2 to l.
Although the appratus described can be considered as
having two treatment zones, one having a group of si~ heads and
the other a group of two heads, separated by a drying head, it is
possible to use other numbers of heads in each treatment zone
and/or more than two treatment zones. It is also envisaged that
the cleaning apparatus could have a single treatment zone. Drying
heads could be provided to confine the working fluid if required.
Such apparatus could be used alone or several could be used in
tandem.
Where it is necessary to clean different sizes of wire
on rod it ~nay be convenient to provide interchangeable heads so
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that the diamet.er of the secondary chambers can be selected -to
suit the diameter of the wire being cleaned.
As well as wire, apparatus of the type described above
may be used to clean rod, or strip.
In the case of strip this could be done by confining
the vibrations to a plane transverse to the plane of the major
surface of the strip and passing it between a pair of rollers.
For polygonal wire or rod sets of rollers may be used as
appropriate.
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