Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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AIR DISTRIBUTING MANIFOLD FOR A HYDROVAC TANK
FIELD OF THE INVENTION
[0001] The present invention pertains to the field of hydrovac tanks and in
particular to an
air distributing manifold for a hydrovac tank.
BACKGROUND
[0002] Hydro-Excavation is a process where high pressure water is used to
loosen soil,
rocks, clay, gravel and other earth material while it is continually "sucked
up" into a debris
tank for later disposal.
[0003] As early as 1960 catch basin cleaners were adapted for hydro-excavation
but the
technology was crude. Many advancements in the technology for hydro-excavation
were
adapted and refined from industrial scale projects in the oil and gas sector.
Because of the
cold climate and difficult working conditions "daylighting" buried lines with
high pressure
hot water and removing the debris by suction was proving an indispensable tool
in the field.
In the decades of the 70's and 80's, modified vacuum trucks and sewer cleaners
were
adapted for use as suction excavators and by the 90's there was a commercial
demand for
hydro-excavation machines for industrial, municipal and commercial use. The
increasing
demand for non-destructive digging and necessary improvements in the field of
worker
safety are at least some of the driving forces behind the growth of the vacuum
excavation
sector.
[0004] A typical hydrovac system includes a vacuum source, a debris storage
unit and a
water storage unit, wherein the vacuum source is interconnected to the debris
storage unit.
Some hydrovac systems further include filtration systems, for example a
cyclone filter
which can be used to remove debris from the air travelling with the vacuumed
material into
the debris storage unit prior to reentry of this air into the vacuum source.
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[0005] In a hydrovac equipment context, soil and aggregates at a selected
ground location
are cut by hydraulic water jet, with the resulting debris being entrained into
an airflow
created by an air pump. Most of the debris typically is deposited into a
debris holding tank.
This deposition of the debris is done when the incoming air stream enters the
debris holding
tank as the velocity of the air slows down due to a large increase in working
volume. By
slowing down the air stream, debris entrained within the air stream separates
and collects in
the debris holding tank. After exiting the debris holding tank, further
purification of the
airflow is typically required through the use of subsequent cyclones and/or
air filters. It is
necessary to purify the air stream in order to ensure reliable operation of
the air pump.
However additional air purification comes at a cost, both in added equipment
cost as well as
a cost to the performance and fuel efficiency of the operating equipment.
[0006] Therefore there is a need for a new air filtering device for a hydrovac
system that
overcomes one or more of the problems in the prior art.
[0007] This background information is provided to reveal information believed
by the
applicant to be of possible relevance to the present invention. No admission
is necessarily
intended, nor should be construed, that any of the preceding information
constitutes prior art
against the present invention.
SUMMARY OF THE INVENTION
[0008] An object of the present invention is to provide an air distributing
manifold for a
hydrovac system. In accordance with an aspect of the present invention, there
is provided
an air distributing manifold for a hydrovac tank having an entry aperture and
an exit
aperture, the air distributing manifold comprising a lower plate having a
length and a width,
wherein the width decreases over the length of the lower plate. The air
distributing
manifold further includes two side plates coupled to opposite sides of the
lower plate, the
side plates configured to compress air flowing along the length of the lower
plate, wherein a
narrow end of the lower plate is positioned proximate to the exit aperture and
the lower
plate extends into the interior of the hydrovac tank.
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BRIEF DESCRIPTION OF THE FIGURES
[0009] FIG. 1 illustrates an elevation view of a hydrovac tank having an air
distributing
manifold in accordance with embodiments of the present invention, installed
therein.
[0010] FIG. 2 illustrates a sectional view of the air distributing manifold in
accordance
with embodiments of the present invention, wherein the sectional view is taken
along line
A-A illustrated in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
[0011] It is noted that by slowing down the air stream upon entry into the
larger working
volume of the debris holding tank, debris entrained within the air stream
separates and
collects in the debris holding tank. However after exiting the debris holding
tank, further
purification of the airflow is typically required in order to provide air with
minimal
entrained debris which may impact the operation of the air pump associated
with the
hydrovac system. As such, subsequent to exiting the debris holding tank, the
airflow
typically travels to cyclones and/or air filters for further debris removal.
As noted above, it
is necessary to purify the air stream in order to ensure reliable operation of
the air pump,
however, this additional air purification comes at a cost. This cost can be in
both the
requirement of additional systems and equipment being required in the hydrovac
system, as
well as cost to performance and fuel efficiency of the hydrovac system.
[0012] Accordingly a new technique for enhancing debris removal from the air
flow while
the airflow is present within the debris holding tank is desired. In
accordance with
embodiments of the present invention, an air distributing manifold is
positioned and
operative within the interior of the debris holding tank of the hydrovac
system.
[0013] According to embodiments, the air distributing manifold is configured
to aid in the
recirculating of the airflow within the debris holding tank prior to exit from
the tank,
thereby enhancing the precipitation of entrained particulates within the air
stream. In this
manner, the air distributing manifold is configured to cause the air flow to
recirculate in the
debris holding tank thus providing a virtual barrier between the incoming
debris and the
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outgoing air. According to embodiments, the air distributing manifold can
cause the
outgoing air to slow down sufficiently such that substantially all of the
entrained
particulates drop out of the air flow in advance of air exiting the debris
holding tank.
100141 In a hydrovac equipment context, soil and aggregates are loaded into a
storage
tank in order to be moved to another location, while a second tank stores
water which is
used to cut into the ground. Plural hydrovac systems include separate water
and debris
storage units which are manufactured as separate entities and mounted onto a
vehicle.
Other hydrovac systems include a tank device which has been divided into two
compartments, wherein a first compartment water can be used to stored for use
at the
excavation location and a second compartment can be used for deposition of the
debris
upon vacuuming from the excavation location. This configuration of tank is
typically
referred to as a dual function tank.
[0015] These dual function tanks typically include a divider wall and/or floor
which
forms a barrier separating the debris storage compartment from the clean water
supply
compartment. It is known that these separating barriers are typically made
with flat sheet
metal with adequate reinforcement and structural components to withstand the
vacuum
pressure generated in the debris storage compartment as well as and the impact
of the debris
upon entry into debris storage compartment. It is common for these barriers to
include a
sloped floor section to aid in removal of the debris from the tank.
100161 FIG. 1 illustrates a side view of a hydrovac tank which includes an air
distributing
manifold configured in accordance with embodiments of the present invention.
The
hydrovac tank 1 includes a turret mount 2, which is a location of an opening
defined in the
tank through which material can be loaded into the debris storage compartment
6 of the
hydrovac tank. A boom and hose can be attached to the turret mount wherein the
hose is
guided to the desired excavation location by the boom. During operation, a
vacuum source
will be activated such that the debris storage compartment is depressurized
causing a
suction force to be created at the opening of the pipe such that material in
the proximity of
the opening of the pipe will be sucked up and subsequently deposited in the
debris storage
compartment. The hydrovac system further includes a dumping door frame 3 to
which a
door is pivotally and sealingly connected. The opening defined by the dumping
door frame
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provides a location from which material can be removed from the debris storage
compartment. In addition, the air flowing through the debris storage
compartment exits via
air exit aperture 7, proximate to which is positioned an air distributing
manifold 5 in
accordance with embodiments of the present invention. The hydrovac tank
further includes
a water storage compartment, which is separated from the debris storage
compartment by
the sloped floor 4, and this water storage compartment can be positioned below
the debris
storage compartment and can provide a volume within which water can be stored
and used
during the vacuuming process.
[0017] According to embodiments, the air distributing manifold is positioned
below the
air exit aperture thereby inhibiting the air flow which enters the debris
holding tank and
travels along the sloped floor from exiting out of the air exit aperture. By
limiting this air
flow possibility the air distributing manifold is increasing the probability
of the recirculation
of the air flow within the debris holding tank, thus enhancing the
deceleration of the air
flow. Moreover by decelerating the air flow, the particulate that is entrained
within the air
flow has a higher probability of precipitation from the air flow. With further
reference to
FIG. 1, the travel of the air flow into the tank 10 and the subsequent
recirculation 11 is
illustrated.
[0018] According to embodiments, the air distributing manifold includes a
lower plate
and side plates coupled thereto, wherein the lower plate is positioned
proximate to the air
exit aperture in the debris holding tank. An embodiment of the air
distributing manifold is
illustrated in FIG. 1, two side plates 21 are positioned on opposite sides of
the lower plate
22 such that the air filtering device essentially &inns a pan, which may be
considered to be
similar to the shape of a dust pan. The lower plate can be oriented such that
it has a slope
associated therewith wherein this slope is configured to be at its highest
proximate to the air
exit aperture and sloping downwards away from this position. This sloped
nature of the air
distributing manifold is illustrated in FIG. 1. The air flow which is
recirculating 11 within
the debris holding tank, can travel over the front edge 20 of the air
distributing manifold,
and is guided by the air distributing manifold towards the air exit aperture.
[0019] According to embodiments, the lower plate is configured to be wider at
the front
edge and decreases in width along its length to the air exit aperture. The
side plates
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positioned along the lower plate are configured to compress the air flow,
thereby reducing
the speed thereof, thus further causing entrained debris to precipitate out of
the air flow and
onto the lower plate. Due to the slope of the lower plate this precipitated
debris can be
guided and travel towards the main portion of the debris holding tank. It
would be readily
understood that the lower plate of the air distribution manifold may have a
varying slope
over it length. For example the lower plate can have a curved slope over its
length or the
slope can have one or more discrete slope changes over the length of the lower
plate.
[0020] FIG. 2 illustrates an embodiment of the air distributing manifold in
accordance
with embodiments of the present invention. As illustrated, as the air flow
enters the air
distributing manifold via the front edge 20, the air flow 13 is compressed
towards the exit
end 23 of the air distributing manifold. This compression of the air flow is
provided by the
side plates 21 together with the configuration of the lower plate which has a
decreasing
width further away from the front edge thereof. This compression of the air
flow results in
the decrease in the velocity of the air flow and enables further precipitation
of debris which
is entrained within the air flow.
[0021] According to embodiments, the width reduction of the lower plate along
its length
can be determined based on the desired level of compression and resulting
reduction in air
flow velocity, such that a desired level of debris precipitation is enabled
from the air flow,
as well as a desired level of air volume movement into and out of the debris
storage tank is
provided. It would be readily understood that if the air flow is decreased to
a particular
level, the volume of air entering the debris storage tank may be greater than
the air exiting
the debris storage tank and after a period of time this can result in an
increase in the
pressure within the tank which may potentially reduce the operational
characteristics of the
hydrovac system. These and other considerations can provide a means for
determining
appropriate configurations of the air distribution manifold and the
configurations of the
componenst thereof.
[0022] According to embodiments, the lower plate can be configured as a flat
plate, a
curved plate, a multi-slope plate or other configuration as would be readily
understood by a
worker skilled in the art. For example, the lower plate can have a "V" shape,
wherein the
vertex of the "V" is aligned along the length of the lower plate. In this type
of
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configuration, the debris that precipitates from the air flow on the lower
plate of the air
distribution manifold may move to the centre of the lower plate which may
enhance the
movement of the debris off of the lower plate and into the main portion of the
debris storage
tank.
[0023] According to embodiments, the front edge of the lower plate can have
non-linear
configurations, for example the front edge can have a concave shape curving
towards the
exit end of the air filtering device. In some embodiments, this front edge can
be 'V" shaped
with the vertex of the "V" being closer to the exit end. Other curvilinear
shapes of the front
edge are also possible as would be readily understood by a worker skilled in
the art.
[0024] According to embodiments, the length of the lower plate, namely the
distance that
the lower plate protrudes from the air exit aperture can be dependent on the
size of the
debris storage tank or the desired level of recirculation within the debris
holding tank or
both. For example, if the lower plate is too long, the air distributing
manifold may inhibit
the desired level of recirculation of the air flow within the tank to a
smaller volume of the
debris holding tank when compared with a lower plate which is shorter in
length. It would
be readily understood that the specific length of the lower plate can be
determined through
experimentation with a particular debris holding tank, in order that the
desired level of
recirculation of the air flow can be provided.
[0025] According to embodiments, the side plates of the air distributing
manifold can be
connected to the lower plate such that these side plates are substantially
perpendicular to the
lower plate. In other embodiments, the plates are aligned with the lower plate
at a more
obtuse angle, resulting in the side plates being spaced further apart at a
location away from
the lower plate. The configuration and alignment of the side plates relative
to the lower
plate can be dependent on the desired effect that the air distributing
manifold has on the
recirculation of the air within the debris storage tank.
[0026] In some embodiments the side plates are rectangular in their side
profile or the
side profile may be an alternate shape. The shape of the side plates can be
dependent on the
desired effect that the air distributing manifold has on the recirculation of
the air within the
debris storage tank. In some embodiments, as illustrated in FIG. I, the side
plates can have
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a relatively small height proximate to the front edge 20 of the air
distributing manifold and
a larger height at locations removed from the front edge. In some embodiments,
the change
in the height of the side plates can change in a curvilinear nature along the
length of the side
plate or the change in the height of the side plates can be in a stepwise
nature along the
length of the side plate.
[0027] According to embodiments, the air distributing manifold can be
configured to be
installed in the debris storage tank upon initial fabrication of the tank, or
alternately the air
distributing manifold can be configured such that it can be a modification to
an existing
debris storage tank. For example for a modification installation of the air
distributing
manifold, the air distributing manifold may be connected to the debris storage
tank by
bolting or other connection means that may be readily performed in the field.
[0028] It is readily understood that while the above description of the air
distributing
manifold according to embodiments of the present invention has be integrated
into a
hydrovac tank configured as a dual function tank, which further includes a
sloped floor
which separates the debris storage tank compartment from the water storage
tank
compartment, the air distributing manifold can be integrated into other
hydrovac tank
configurations. It would be readily understood that the air filtering device
according to
embodiments of the present invention, can be integrated into a dual function
tank with a
substantially flat floor separating the debris storage tank compartment from
the water
storage tank compartment. Moreover, the air filtering device according to
embodiments of
the present invention can be integrated into a single function tank, namely a
debris storage
tank. These and other tank configurations where there is a need for debris
removal from an
air flow having this debris entrained therein, may also have an air
distributing manifold in
accordance with embodiments of the present invention integrated therein and
are considered
to be within the scope of the present disclosure.
[0029] According to embodiments, for a hydrovac system, the air distribution
manifold
can provide a means for additional removal of particulate entrained within the
air flow prior
to this air flow exiting the debris storage tank. This further cleaning of the
air flow can
enable the elimination or reduction of further filtration systems to be
integrated into the
hydrovac system, thereby reducing costs of fabrication due to the reduction of
components.
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The elimination or reduction of further filtration systems for the hydrovac
system may
further reduce operational costs, for example fuel costs and/or other costs
associated with
the operation of larger filtration systems.
[0030] It is obvious that the foregoing embodiments of the invention are
examples and
can be varied in many ways. Such present or future variations are not to be
regarded as a
departure from the spirit and scope of the invention, and all such
modifications as would be
obvious to one skilled in the art are intended to be included within the scope
of the
following claims.
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