SYSTEME DE NETTOYAGE DE BASSIN A BOUE

MUD TANK CLEANING SYSTEM

Abrégé français

Un système de nettoyage de bassins à boue comprend un balai de collecte de débris qui entraîne les débris vers une zone de collecte dans un bassin à boue, où les débris peuvent facilement être mécaniquement éliminés au travers d'une ouverture dans le bassin à boue. De préférence, la zone de collecte est dans une partie centrale en creux du bassin à boue pour permettre à la gravité d'aider au déplacement des débris vers la zone de collecte. De préférence, deux balais de collecte sont utilisés sur des côtés opposés de la zone de collecte. Les balais de collecte sont de préférence montés de manière pivotante pour suivre un trajet en forme d'arc le long de la surface d'une paroi de confinement cylindrique du bassin à boue. Des mécanismes d'entraînement entraînent lesdits balais. Les balais de collecte sont de préférence utilisés en liaison avec des balais d'élimination qui ramassent les débris recueillis dans la zone de collecte par les balais de collecte et éliminés hors de la zone de collecte et à travers l'ouverture dans le bassin à boue, d'où ils peuvent facilement être éliminés. Le bassin à boue est généralement utilisé en conjonction avec un véhicule de type hydrovac.

Abrégé anglais

A mud tank cleaning system includes a debris collection sweep that drives debris towards a collection zone in a mud tank, whence the debris can easily be mechanically disposed of through an opening in the mud tank. Preferably, the collection zone is in a central depressed part of the mud tank to allow gravity to assist in moving debris towards the collection zone. Preferably, a pair of collection sweeps are used on opposed sides of the collection zone. The collection sweeps are preferably pivotally mounted to follow an arcuate path along the surface of a cylindrical confining wall of the mud tank. Sweep drive mechanisms operate the sweeps. The collection sweeps are preferably used in conjunction with a disposal sweep that sweeps debris collected in the collection zone by the collection sweeps out of the collection zone and through the opening in the mud tank, from where it may be readily disposed of. The mud tank is typically operated in conjunction with a hydrovac vehicle.

Revendications

8
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A hydrovac vehicle having a frame mounted on wheels and a mud tank mounted
on the frame, the mud tank comprising:
confining walls;
a collection zone in the mud tank for collection of debris under action of
gravity;
an opening in the confining walls of the mud tank, the opening being located
in
sufficient proximity to the collection zone that debris in the collection zone
may be
moved by mechanical action through the opening;
a removable cover mounted on the mud tank over the opening;
a disposal sweep mounted in the mud tank and having an upwardly extending
sweep arm, the disposal sweep being operable to sweep mud in the mud tank
along the
collection zone towards the opening in the confining walls; and
a collection sweep mechanism mounted in the mud tank for sweeping mud along
the confining walls towards the collection zone.
2. The hydrovac vehicle of claim 1 in which the confining walls comprise a
cylindrical connecting wall extending between a pair of end walls.
3. The hydrovac vehicle of claim 2 in which the collection sweep mechanism is
pivotally mounted in the mud tank.
4. The hydrovac vehicle of claim 3 in which the collection sweep mechanism is
pivotally mounted from the end walls.
5. The hydrovac vehicle of claim 1 in which the collection zone is a trough in
the
connecting wall.

9
6. The hydrovac vehicle of claim 1 in which the collection sweep mechanism
comprises a first sweep and a second sweep mounted for sweeping towards the
collection
zone from respective opposed sides of the collection zone.
7. The hydrovac vehicle of claim 6 in which the first sweep and the second
sweep
each have a sweep path that terminates at the edge of the collection zone.
8. The hydrovac vehicle of claim 1 in which the collection sweep mechanism
sweeps along a path that terminates at the edge of the collection zone.

Description

CA 02352619 2006-11-09
TITLE OF THE INVENTION
01 Mud Tank Cleaning System
FIELD OF THE INVENTION
02 This invention relates to devices for cleaning out mud tanks of hydrovac
units.
BACKGROUND OF THE INVENTION
03 In hydrovac operations water is used to blast a hole or trench in soil and
the fluidized
soil thus created is sucked into a mud tank. The water in the mud tank is
filtered and re-
circulated for use in blasting the hole, while mud accumulates in the mud
tank. Periodically,
the mud has to be removed from the mud tank. In the past, removal of the mud
has been
done with hoists, in which the tank is lifted and the mud dumped. This is not
efficient, and
the resulting vehicle is fairly complex.
04 In United States patent no. 6,547,964 filed September 7, 2000, and Canadian
application no. 2,317,667, published March 6, 2001, the inventor has proposed
a solution to
the inefficient removal of mud from a mud tank. In those applications, there
is provided in
accordance with an embodiment of the invention, a mud tank cleaning system,
comprising a
mud tank having confining walls, an opening in the confining walls of the mud
tank, a
removable cover mounted on the mud tank over the opening, a sweep mounted in
the mud
tank and being operable to sweep mud in the mud tank towards the opening in
the confining
walls; and a sweep drive mechanism operably connected to the sweep for
operating the
sweep. The mud collects in a trough at the base of the confining walls, from
where it is
swept by the sweep through the opening.

CA 02352619 2001-07-06
2
05 This prior device relies upon gravity to pull debris into the trough. The
inventor has
now proposed a cleaning mechanism to improve the collection of the debris in
the trough
and thus facilitate rapid and complete cleaning of the mud tank.
SUMMARY OF THE INVENTION
06 There is therefore provided in accordance with an aspect of the invention,
a mud tank
cleaning system that includes a debris collection sweep that drives debris
towards a
collection zone in a mud tank, whence the debris can easily be mechanically
disposed of
through an opening in the mud tank. Preferably, the collection zone is in a
central depressed
part of the mud tank to allow gravity to assist in moving debris towards the
collection zone.
Preferably, a pair of collection sweeps are used on opposed sides of the
collection zone. The
collection sweeps are preferably pivotally mounted to follow an arcuate path
along the
surface of a cylindrical confining wall of the mud tank. Sweep drive
mechanisms operate the
sweeps. The collection sweeps are preferably used in conjunction with a
disposal sweep that
sweeps debris collected in the collection zone by the collection sweeps out of
the collection
zone and through the opening in the mud tank, from where it may be readily
disposed of.
The mud tank is typically operated in conjunction with a hydrovac vehicle.
07 These and other aspects of the invention are described in the detailed
description of
the invention and claimed in the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
08 There will now be described preferred embodiments of the invention, with
reference
to the drawings, by way of illustration only and not with the intention of
limiting the scope
of the invention, in which like numerals denote like elements and in which:
Fig. 1 is a side view schematic of a mud tank for use with sweeps according to
the
invention;

CA 02352619 2001-07-06
3
Fig. 2 is a front view of the mud tank of Fig. 1;
Fig. 3 is a perspective view of the mud tank of Fig. 1;
Fig. 4 is a top view of a drive mechanism for the mud tank sweep arm;
Fig. 5 is a left side view of a hydrovac unit incorporating a mud tank;
Fig. 6 is a right side view of a hydrovac unit incorporating a mud tank;
Fig. 7 is a top view of a hydrovac unit incorporating a mud tank;
Fig. 8 is a top view of a mud tank with side sweeps according to the
invention;
Fig. 9 is en view of a mud tank with side sweeps according to the invention;
Fig. 10 is a side view of a mud tank with side sweeps according to the
invention; and
Fig. 11 is a perspective view of a mud tank with side sweeps according to the
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
09 In this patent document, "comprising" means "including". In addition, a
reference to
an element by the indefinite article "a" does not exclude the possibility that
more than one of
the elements is present.
10 A mud tank cleaning system is shown in Figs. 1, 2, 3 and 4. Figures 1, 2
and 3 show
details of the mud tank 10. The mud tank 10 is formed of confining walls 11,
14 and 16.
The mud tank 10 preferably has a cylindrical wall 11 with a depressed lower
part 12, with
domed access wall 14 and domed end wall 16. The lower part 12 forms a trough
extending
from near the end wall 16 to and beyond the access wall 14. The trough 12
deepens from end
wall 16 to the access wall 14, and has near vertical side walls 18. The trough
12 extends
through a rectangular opening 20 partly in the access wall 14 and partly in
the lower part of
the cylindrical wall 11. The orientation of the trough 12 could be in any
direction that was
suitable for dumping mud from the tank 10. The opening 20 could also be in any
of the
walls, for example entirely in the bottom wall. A removable cover 22 is
mounted on the mud

CA 02352619 2001-07-06
4
tank 10 over the opening 20, and operated by a conventional hydraulic cylinder
24 secured
between the access wall 14 and a projecting arm 26 on the cover 22.
11 A sweep formed of a sweep arm 30 and sweeping blade 34 is mounted in the
mud
tank 10, for example as shown by being mounted to a pivot 32 fastened to the
roof 17 of the
mud tank 10. In operation, the sweep arm 30 pivots and its lower sweeping
blade 34 moves
in an arc along the trough 12 of the mud tank 10 towards the opening 20, thus
being operable
to sweep mud 36 in the mud tank 10 towards the opening 20 in the mud tank 10.
The sweep
arm 30 is provided with a sweep drive mechanism operably connected to the
sweep arm 30
for causing the sweep arm 30 to move across the bottom 14 of the mud tank 10
towards the
opening 20. The drive mechanism is preferably a hydraulic cylinder 38 secured
to the sweep
arm 30 and to the roof 17, as shown in Figure 4. Fluid for the hydraulics
shown in Fig. 1 is
provided by a conventional hydraulic supply and control system. Preferably,
the sweep blade
34 has approximately the same shape, and is slightly smaller than, the opening
20, and is
concave facing the opening 20 to contain mud being swept across the bottom of
the tank.
The concavity of the sweep blade 34 is preferably provided by flanges 35. It
is preferred that
the sweep blade 34 be slightly smaller than the opening 20 since then it can
fully enter the
opening to force mud out of the mud tank 10. The sweep blade 34 is preferably
attached to
the sweep arm 30 using a pivot mount 31, above the bottom end of the sweep arm
30. The
sweep blade will therefore pivot on the sweep arm 30. The sweep blade 34 is
mounted
pivotally on the sweep arm 30 to allow the sweep blade 34 to swing free of mud
in the mud
tank when the sweep blade is moved away from the opening, while pushing mud
out of the
opening on the forward swing towards the opening. The pivot mount 31 is
located a short
distance away from the downward extremity 33 of the sweep arm 30 to form a
stop that
prevents the blade 34 from pivoting out of the way of the mud on the forward
swing when
the sweep arm moves towards the opening 20. Top and side flanges 35 on the
sweep blade
34 assist in collecting the mud and preventing it from spilling over the blade
34 as it is
pushed towards the opening. Conventional materials are used for the all the
elements
shown.

CA 02352619 2001-07-06
12 As shown in Fig. 1, the mud tank also comprises a liquid load riser 39 and
entrance
port 41, both of which are for receiving the fluidized soil in the tank. Air
and other vapors
are suctioned out of the tank 10 through a vapor outlet port 43. An overhead
boom line 45
5 can be used to transport fluidized soil to the entrance port 41. These
components are known
in the art and need not be further described here.
13 The mud tank 10 in Fig. 1 is shown in Figs. 5, 6 and 7 combination with a
hydrovac
vehicle 40 with water tank 42, and mechanical storage 44, having a blower 46,
water pump
48 and power take offs 50, 51 from an engine (not shown). The water tank 42 is
preferably
formed of a cylinder welded to the end wall 16 of the mud tank 10 and closed
at the opposite
end by a water tank end wall 72, thus forming a combination mud/water tank
with an
intervening divider, the end wall 16. The mud tank 10 and water tank 42 are
bolted directly
to the fame 47 of the hydrovac vehicle 40.
14 The blower 46 is bolted directly to the left side of the frame 47 of the
hydrovac
vehicle 40 forward of the water tank 42, and is connected directly by a drive
shaft 52 to the
power take off 50. The blower 46 sucks air through a conventional cyclone
separator 54
through line 56. The cyclone separator 54 is connected by suction line 58 to
the outlet 43
from the mud tank 10. Operation of the blower 46 sucks air out of the mud tank
10 into the
cyclone separator 54. A cooling air silencer 60 and discharge air silencer 62
are also
provided on the hydrovac vehicle 40.
15 Water pump 48 is bolted to the frame 47 of the hydrovac vehicle 40 in front
of the
water tank 42, and is connected directly to power take off 51 by direct drive
shaft 64. Water
pump 48 pumps water out of the tank 42 for use in the hydrovac digging
operation through
hose 65 and other conventional hoses (not shown). The water tank 42 is also
provided with a
water level indicator 66 and access port 68. The hydrovac vehicle 40, water
tank 42,
mechanical storage 44, blower 46, water tank 48, power take offs 50, 51,
cyclone 54,

CA 02352619 2001-07-06
6
silencers 60, 62 and their associated connections are all conventional. On the
other hand, it is
believed to be new to mount the water pump 48 and blower 46 directly to the
frame 47 of the
hydrovac vehicle where they are readily accessible for direct drive straight
to the PTO 50, 51
for operation and maintenance. The hydrovac vehicle 40 is preferably a truck
mounted on
wheels 70.
16 The hydrovac vehicle 40 has fewer moving parts and components that make it
economical to build and allows for fewer breakdowns. The modular design allows
the
blower 46 and water pump 48 to be mounted on the frame 47 low down so that the
drive
shafts from the power take offs 50, 51 are short and simple. The combination
mud/water
tank has few moving parts and components, and the boom 45 may be mounted
directly to the
end of the mud tank 10. Use of the reciprocating sweep allows the mud tank to
be bolted
directly to the frame, and thus allows the hydrovac vehicle to be kept simple
with few
moving parts. Although a preferred pivotally mounted sweep is shown, the sweep
may be
mounted in various ways to produce a sweeping action, including by being
mounted on a
reciprocating ram.
17 Referring to Figs. 8, 9, 10 and 11, the side sweeps of the invention will
now be
described. The sweeps are mounted in the mud tank 10 as described in relation
to Figs. 1-7,
with end walls 14, 16 and side connecting wall 11 which connects to the end
walls 14, 16
about their respective peripheries. The depressed lower part 12 forms a
collection zone for
debris to collect under force of gravity in the mud tank in sufficient
proximity to the opening
20 that debris in the collection zone may be moved by mechanical action, such
as by sweep
34, through the opening 20. A pair of collection sweeps 80, 82, are mounted on
opposed
sides of the mud tank 10 to move in arcuate paths along the side connecting
wall 11 from a
position mid way up the connecting wall 11 to the collection zone 12. The
collection sweeps
80, 82 may be made of any suitable material, and could be made of plastics or
metal, and
may be any suitable shape, such as round tubes as shown. Preferably, the
collection sweeps
80, 82 are suspended on booms 84, 86 which rotate about pivots 88, 90 on
respective end

CA 02352619 2001-07-06
7
walls 14, 16. Use of the pivots 88, 90 at the axis of the cylinder formed by
the connecting
wall 11 allows the sweeps 80, 82 to easily follow the curve of the connecting
wall 11. The
booms 84, 86 lie along a radius of the circle defined by a section through the
cylindrical
connecting wall 11. Each sweep 80, 82 is driven by a respective sweep drive
mechanism 92,
94, respectively. The sweep drive mechanisms 92, 94 may be for example
hydraulic
cylinders fastened between a central point of the sweeps 80, 82 and respective
pivot points
96, 98 on an upper part of the connecting wall 11. Operation of the sweep
drive mechanisms
92, 94 drives the sweeps 80, 82 along the connecting wall 11 towards the
collection zone 12.
Any of various other structures may be used for the sweep drive mechanism such
as motors
attached to the pivots 88, 90. The sweeps 80, 82 are used in conjunction with
the disposal
sweep 34. Conventional hydraulic controls (not shown) are used for the sweep
drive
mechanisms 92, 94.
18 Immaterial modifications may be made to the invention described here
without
departing from the essence of the invention.

Dessin représentatif