Note: Descriptions are shown in the official language in which they were submitted.
This lnven-tion rela-tes to an apparatus for clean-
ing up an oil spill in a harbour or elsewhere.
The task of clearing a harbour of a contaminating
substance such as oil is an extremely difficult one par-
ticularly when the sea conditions are poor or the -tem-
perature is low as so often appears to be the case. One
machine employed for this task is equipped with an endless
fabric belt which is mounted at the bow of a boat to incline
downwardly into the water. sy rotating the belt, oil is
lifted up and transferred to a location aboard the boat
where it is scraped off the belt and deposited in a holding
tank. Another device suggested for the same task is equipped
with a multitude of ver-tically standing metal di.scs which
are mounted in a float serving as an intake for a pumping
system. The discs are rotated to pickup the oil but again
the oil must be scraped off the discs with a result that the
oil discharging problem is only slightly easier than is the
case where an endless fabric belt is employed.
The present invention overcomes the disadvantages
of the above mentioned oil recovery systems by providing
apparatus which is equipped with fabric discs. Such pickup
members have been found best suited for lifting the oil off
the surface of the water and the flexibility of such a
material has a number of secondary advantages as well~ For
example, the flexible discs can operate with reasonable
effectiveness when the water surface is roughened or there
is floating debris or ice to contend with. The discs form
part of a conveyor which operates continuously to raise oil
off the water surface and into a barge. When partly immersed
t7'~66
in the water, the discs are ro-tated slowly to ensure a
maximum oil load. The oil is discharged from the discs
aboard the barge by rotating them at a speed sufficiently
hiyh to throw off the oil by centrifugal force. If neces-
sary, hea-t and a cleaning fluid is applied to the rapidly
spinning discs to assist in -the discharge of the oil.
More specifically, according to the present
invention, there is provided apparatus for recovering oil
floating on a body of water which comprises a vessel movable
over the water through the floating oil, said vessel being
equipped with oil catching means, and oil lifting mechanism
mounted on the vessel and including a plurality of pickup
discs arranged in sets each rotatable about a horizontal
axis extending transversely of the mechanism, means for
operating the oil lif-ting mechanism to move each set of
pickup discs in turn between a loading position at least
partly immersed in the water and a discharge position
adjacent the oil catching means, and drive means for rota-
ting each set of pickup discs at a first speed in the
loading position whereby the discs are coated with oil and
at a second speed in the discharged position whereby at
least a portion of the oil adhering to the discs is thrown
by centrifugal force into -the oil catching means.
In drawings which illustrate a preferred embodi-
ment of the invention,
Figure 1 is a schematic side elevational view ofoil recovery apparatus constructed in accordance with the
present invention,
Figure 2 is a schematic plan view of the appara-
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tus,
Figure 3 is a plan view of a portion of a conveyorchain assembly of the apparatus,
Figure 4 is an enlarged vertical section taken on
the line 4-4 of Figure 2 showing one of the driven reels of
the conveyor,
Figure 5 is a view similar to Figure 4 but showing
an idler wheel of the conveyor,
Figure 6 is an enlarged vertical section of a
tunnel structure of the appara-tus showing a cross member of
the conveyor supported thereby,
Figure 7 is an enlarged vertical section of a
housing provided on each cross member,
Flgure 8 is a schematic side eleva-tional view
showing drive means of the apparatus,
Figure 9 is a plan view of the drive means.
The apparatus 10 primarily is intended for use in
cleaning up an oil spill in a harbour or elsewhere and
therefore a suitably constructed barge 12 is used to carry
the present apparatus. Preferably, the barge is self
propelled so that it can move back and forth across the
harbour as is required to gather in the floating oil and
lift it off the surface of the water. Apparatus 10 is
provided with an oil lifting mechanism which is shown to
comprise a conveyor 14. The conveyor operates to transfer
oil from the water to catching means 16 aboard the barge
where the oil is temporarily held until it can be trans-
ferred to a shore facility. The conveyor 14 is carried
beneath a hood 18 which is mounted on the barge to project
forwardly of the bow. The floating oil normally forms only
a relatively thin layer spread over a large area so the
present apparatus includes sonic sweeping equipment 20 which
serves to gather the oil into a pool beneath the hood where
it can readily be picked up by the conveyor.
The sonic sweeping equipment generally indica-ted
at 20 relies mainly on acoustic energy to propel the float-
ing oil towards the path of travel of the barge. This type
of sweeping action is disclosed in Canadian Patent No.
1,067,709 granted to this applicant on November 12th, 1979
for an invention entitled MEANS AND MET~IOD FOR SWEEPING
MATRRIAL FLOATING ON WATER USING VI~RATION ENERGY. In the
present invention, the equipment 20 will be seen -to be
provided with a pair of arms 22 the rearmost ends of which
are mounted on laterally projectin~ pivots 23 secured to the
front end of the hood 18. The arms curve downwardly from
their pivots and then diverge outwardly from the hood to
generally horizontal sections 24 of the arms which are
interconnected by hinges 25. A float 26 is secured beneath
each section 24 and the buoyancy of these floa-ts is such
that the several sections are supported on or at least just
below the surface of the water. Depending from each float
26 is a sound producing device or transducer 27. A suitable
electric circuit, not shown, connects the several trans-
ducers to equipment aboard the barge such as an oscillator
and a source of alternating current. This equipment is
operable in the manner described in detail in Canadian
Patent No. 1, 067,709 to energize the several -transducers
whereby ultrasonic waves are generated. The transducers are
aimed upwardly towards the water surface and also inwardly
of the arms so that the sound waves generated produce at the
surface an acoustic force which reacts with the air above
the oil covered surface and provides a sweeping action as
taught by the above mentioned patent. This vibrational
energy serves to sweep the oil between the arms which also
act as sweeps and so that the oil collects as a pool beneath
the hood 18 and in the pa-th of travel oE the conveyor 14 as
the barge moves ahead.
The conveyor generally indicated at 14 comprises a
number of horizontal shafts 30 one of which is shown in
detail in Figure 3. Each of these transversely extending
shafts has opposite ends journalled in bearings 32 which are
mounted in hollow floats 33. The shafts each rotatably
extend through a cylindrical housing 35 which is equidis-
tantly spaced between the floats. The cylindrical floats 33
and the housing 35 on adjacent shafts are connected togetherby lengths of cable 36 so that the spaced apart shafts and
associated parts plus the mul-tiple connecting cables form an
endless assembly 38 comparable to a conventional conveyor
chain. Between the floats and the housing, each shaft has
enlarged cylindrical portions 40 on which two transversely
spaced sets of discs 41 are mounted. These discs are formed
of annular bands of a suitable woven fabric to which oil
will readily adhere and the fabric is a type which will
resist penetration by water. As shown best in Figures 4 and
5, the fabric discs are secured to the shaft portions 40 by
hollow hubs 42 and preferably the flexible fabric is stiffen-
ed to a suitable extent by radial strips 43 formed of the
same fabric material.
The endless assembly 38 of the conveyor is mounted
in pairs of drive and driven reels indicated at 50 and 51
respectively. In order -to support -the assembly 38, the hood
18 is provided with a horizontal top wall 53 and vertical
side walls 54. Figure 4 shows one of the reels 50 as having
a spindle 56 mounted in a bearing 57 which is carried by one
of the side walls 54 of the hood. This reel has circular
flanges 58 and 59 in which circumferentially spaced notches
60 and 61 respectively are formed. The cylindrical bearings
33 in which the transverse shafts are rotatably mounted are
received in the notches 60 and the cylindrical housing 35
enters the notches 61 as shown in Figure 4. Another iden-
tical reel 50 is similarly moun-ted on the other side wall 54
of the hood in transverse alignment with the above described
driven reel but, for convenience, this other driven reel is
shown only by dotted lines in Figure 1.
A pair of the reels 51 are also mounted in -the
side walls 54 of the hood where the rearmost end oE the top
wall 53 extends over the deck of the barge. Figure 5 shows
one reel 51 as having a spindle 63 journalled in a bearing
64 secured to a side wall 54 of the hood. Circular flanges
20 65 and 66 on the reel 51 are provided with a tooth forming
arrangement of notches 67 and 68 respectively, the notches
being adapted to receive the bearings 33 and an end part of
the housing 35. Thus, the chain like assembly 38 is trained
over the pairs of reels 50 and 51 much as a conveyor chain
is trained over drive and drlven sprockets. The reels 50
are the driven members in this instance while the reels 51
are idler members.
In order to drive the pair of reels 50 and operate
the conveyor, the apparatus 10 is provided with means which
30 is generally indicated at 70 in Figures 1, 2 and 4. The
:L~
operating means 70 is shown to comprise an electric motor 71
which is supported on top of the hood beneath a suitable
cover 72. Motor 71 has a reduction gear connecting the
drive shaEt of the motor -to two aligned shafts 73 which are
journalled in bearings 74 so as to extend across the hood
and project beyond the side walls 54. Chain and sprocket
drives 75 connect the overhanging ends of the shaf-ts 73 to
the spindles 56 of the pair of reels 50. Preferably, the
drives 75 are enclosed within protective covers 76 secured
to the side walls of the hood. The motor 71 is connected by
appropriate circuitry to a suitable source of power aboard
the barge where a swi-tch is located to allow a crew member
to control the motor.
Operation of the motor 71 rotates the endless
assembly 38 in a clockwise direction as used in Figure 1
where it will be noticed the lower run of the assembly is
quite slack, that is, it hangs down below the hood 18 to
move across the surface of the water. The floats 33 provide
a certain amount of buoyancy at this time so that the
flexible discs 41 normally are not totally submerged. Oil
adheres to the discs in this location which will hence-
forth be referred to as the loading position of the pickup
discs. The upper run of the assembly 38 is supported by the
drive and idler reels 50 and 51 with very little slack and
the upper run is further steadied and held taut by guide
rails 78 and 79 which are shown by dotted lines in Figure 1.
Portions of these rails are secured to inner surfaces of the
hood in position to slidably receive the floats 33 and
housings 35 as the endless assembly 38 is rotated. It is
along the upper run where oil is thrown off the flexible
~7~6~i
discs and, at this discharge position, the oil catching
means 16 is located.
As shown in Figure ~, the means 16 comprises a
tunnel like structure 80 located below the top wall 53 of
the hood between the driven and idler reels. The guide
rails 78 and 79 extend through and are partly supported by
this open ended structure to slidably receive the floats 33
and housings 35. The housings move through a tunnel 81 in
that structure and the sets of discs 41 travel through
tunnels 82 which are in communication with storage chambers
83 and 84 provided in -the structure 80. Oil thrown off the
discs within the tunnels flows first into the chambers 83
and then into the chambers 84 where the oil is drawn off
through pipes 85. These pipes extend alongside the hood to
the stern oE the barge 12 where they connect with a holding
tank (not shown) carried by the barge. Suitable pumping and
control devices are provided to allow oil collected in the
storage chambers 84 to be moved through the pipes to the
holding tank.
The flexible discs 41 are rotated about the axes
of their transverse shafts as they travel around the circum-
ference of the conveyor. Rotation of the discs is Eairly
slow along the lower run of the conveyor but it is necessary
to spin the disc quite rapidly when they are in the dis-
charged position in order to throw off the oil by centri-
fugal force and therefore the apparatus 10 is provided with
a two speed drive means generally indicated at 90. In
Figure 7, the drive means 90 will be seen to comprise a
turbine wheel 92 secured tp each shaft 30 within the housing
35. The barge is equipped with a steam generator 93, see
~76~
Figures 1 and 2, the generator delivering controlled amounts
of suitably pressuri~ed steam through pipes 94 to a rota-
table manifold 95 which is shown schematically i.n Figures 8
and 9. The manifold is located between the drive and idler
reels in about the center of the endless assembly 38.
Flexible tubes 96 are connected at one end to the maniEold
and at their opposi-te ends these tubes are connected by
couplings 97 -to an endless tube 98. At intervals of its
length, a tube 98 is connected by an inlet 99 to each of the
housings 35. Steam enters each housing 35 through the inlet
99 and travels through a port 101 (Figure 7) into a chamber
102 in which the turbine wheel 92 is located. A small
outlet 103 vents each chamber 102 to atmosphere.
Such a steam system provides the power which
enables the drive means 90 -to rotate the discs at the two
required speeds. These two speeds are regulated automa-
tically by a control arrangement which is shown best in
Figure 7 as comprising a valve plate 106 which is slidably
supported by parts 107 of each housing 35 for limited
reciprocatory movement. A piston 108 is provided on the
plate to reciprocate in a cylinder 109 formed in the housing.
The valve plate extends across the port 101 and the plate is
provided with an end slot 110 as well as with longitudinally
spaced openings 111 and 112. Cylinder 109 is connected by
ducts 114 and 115 to vertical cylinders 116 and 117 which
project through the top of each housing. These vertical
cylinders are fitted with plungers 118 and 119, the lat-ter
plunger being urged outwardly by a spring 120. A quantity
of oil which is indicated at 121 fills the cylinder 109, the
_g~
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ducts 114 and 115, and the cylinders 116 and 117 beneath the
plungers in those cylinders. On the underside of -the
structure 80, there is a cam track 12~ located between -the
driven and idler reels and this ~am ~rack is disposed in -the
path of travel of the plunger 118. Another cam track 125 is
attached to the ~Inderside of the structure 80 in the path of
travel of the plunger 119. This plunger 119 is fitted with
an adjusting screw 127 which has sliding contact with the
track 125. The two cam tracks are longitudinally spaced
apart above the upper run of the conveyor so as to be
engaged by an appropriate intervals by the plungers. The
arrangement is such that pressurized steam reaches the
chamber 102 through the port 101 in which the opening 111 is
now located to drive the turbine wheel at a speed of jus-t a
few revolutions per minute whenever each housing 35 is
outside the tunnel structure 80, -that is to say, when the
housing forms part of the lower run of the conveyor chain
assembly. The discs are thus rotated slowly particularly
when in the loading position where they are partly submerged
in the water. The slow rotation of the discs ensures that
the entire surface of the fabric is coated with oil before
they move up out of the water and under the forward end of
the hood.
As a set of discs 41 which have been coated with
oil approaches the forward end of the structure 80, the
plunger 118 is depressed by its cam track 124 to force the
valve plate 106 to a position where the slot 110 is aligned
with -the port 101. A greater amount of steam is now able to
enter the chamber 102 through the port in which the slot 110
--10--
~'7~
is now located and, as a resultl the turbine wheel 92 is
driven to spin the oil loaded se-t of discs at a speed
sufficient high to throw off oil by centrifugal force. This
thrown off oil is caught by in-terior parts of the struc-ture
S 80 and is collected in -the chambers 83 eventually to reach
the chambers 84 and be drawn off through the pipe 85.
Each set of discs is rid of most of the adhering
oil in this manner and, as the discs approach the idler
wheels 51, the rapid spinning is reduced to the former slow
rotation by the above described valve arrangement. This is
achieved when the plunger 119 is depressed by the cam track
125 thus forcing the cam plate 105 back to the Figure 7
position. The limited amount of pressurized steam which now
reaches the turbine wheel 102 through the port 101 and
opening 111 is sufficient only to keep the discs rotating a-t
the desired slow speed which is maintained as the unloaded
discs travel along the lower run on the conveyor to pick up
more oil.
Referring now particularly to Figures 7 and 10,
each shaft 30 will be seen to be tubular so as -to have a
bore 130 which extends through the cylindrical portion 40 of
the shaft. The bore is in communication with the hollow
hubs 42 by virtue of circumferentially spaced apertures 132.
Arranged around the hubs are a number of nozzles 133 which
are directed towards the annular bands of the adjoininy
discs. The shaft has other relatively large apertures 135
located within the housing 35 as shown in Figure 7 so that
the nozzles 133 can be supplied with some of the steam which
is delivered to the housing 35 to drive the turbine wheel.
A suitably small proportion of the live steam is
11--
dlverted into the interior of each housing 35 at the time
the discs adjoining that housing are spun rapidly to throw
off oil. The piston 108 is moved to the right (Figure 7) to
shift the slot 110 across the por-t 101 and this movement
also places the opening 106 in the valve pla-te wi-thin a port
137 provided in the housing. Steam then reaches the nozzles
133 through the apertures 135, bore 130 and apertures 132 to
discharge against the discs. Thus, -the apparatus 10 is
provided with means for applying heat to the pickup discs 41
in the discharge position whereby to reduce adhesion of the
oil.
The flexible discs which are discharged of most of
their oil load by centrifugal force and are also steam
heated to assist in this unloading can be cleared of mos-t of
the remaining oil residue by khe application of a cleaning
fluid. Preferably, a suitable solvent is used for thls
purpose, the cleaning fluid being injected into the structure
80 through nozzles 140 whlch appear in Figure 6. The
nozzles are mounted on top of the hood 18 to extend into the
tunnels 82 through which the sets of discs must travel when
in the discharge position. Hoses 141, see also Figure 2,
connect the nozzles to a unit 142 provided on the barge 12
to supply so]vent under pressure. The cleaning fluid
preferably is injected intermittently into the tunnel 8 in
timed relation to the passing of the discs through those
tunnels so as to lmpinge upon the steam heated discs and
remove most of any oil which may be left clinging to the
flexible discs 41. The injected solvent mixes with the
recovered oil in the chambers 82 and 83 so as to be pumped
into the holding tank where it can later by separated and
7~
reused. By this arrangement, the apparatus 10 is provided
with means for directing a cleaning fluid at the pickup
discs in the discharge position.
In operation, the present oil recovery apparatus
is moved ahead at a reasonably slow speed -to advance on a
floating oil slick. The diverging arms 22 oE the equipment
20 serve to some exten-t as booms which collect the floating
oil in front of the advancing barge and, when the ultrasonic
devices 27 are energized, the oil is propelled into a
relatively thick layer immediately in front of the conveyor
1~. The conveyor, which is run continuously during a
recovery operation, moves the rotating pickup discs progres-
sively through the oil layer allowing the discs to become
coated with oil. The floats 33 serve to keep at least the
upper portion of the discs projecting above the oil layer
and it is in thi.s region where most of the loading talces
place. It may happen that debris or even small chunks of
ice will strike the discs but, since they are flexible, no
damage is done. The surface of the water may be roughened
to some extent but this does not affect the pick up action
of the discs. In point of fact, it may improve the action
since the discs themselves adapt a wavey configuration most
notable near the circumference of the discs and this appears
to increase the amount of oil which clings to the fabric
discs and subsequentl.y is lifted clear of the surface of the
water.
The loaded discs s-till rotating slowly are raised
and moved along the upper run of the conveyor which travels
through the tunnel like structure 80. As previously mentioned,
i6
the discs are spun rapidly when travelling through -the
tunnels 82 to throw off most of -the clinging oll by cen-
trifugal force. IIot steam is applied to the discs to raise
the temperature of the oil and assist in the throwing off
action. The application of solvent cleans the discs to the
extent that -they can later lift a maximum amount of oil when
the rotating conveyor again wipes them through the floating
oil layer.
From the foregoing, it will be apparent the
present oil recovery apparatus provides an effective means
and method of picking up oil spilled in a harbour or else-
where. The use of flexible discs as pick up members avoids
the likelihood they will suffer the type of damage which
might be inflicted on metal discs by floating debris. By
unloading the discs mainly by cen.tri~ugal force, the need to
use wiper blades to clear the discs is avoided and this
simplifies and improves the effectiveness of the clean up
operation.
-14-
