Note: Descriptions are shown in the official language in which they were submitted.
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COLLECTION MEANS FOR A MOBILE VACUUM APPARATUS FOR THE
COLLECTION OF LIQUID OR SEMI-LIQUID MATERIALS
Field of the Invention
[0001] The invention relates to the mobile pneumatic collection of liquid or
semi-
liquid materials such as animal manure. More specifically, the invention
relates to a
collection means for mounting beneath a mobile vacuum apparatus to direct the
liquid
or semi-liquid materials into a suction inlet when the apparatus is driven
through the
materials.
Background of the Invention
[0002] Animal husbandry facilities, such as dairy or hog barns, include alleys
or
gutters for manure collection. Vehicles such as tractors or skid-steer loaders
are
equipped with scraper blades or front-end bucket systems to transfer manure
accumulated in the alley or gutter to one end of the barn for removal and
disposal.
The manure is typically liquid or semi-liquid and is often difficult to
transfer in this
manner, as it escapes around the sides of the scraper blade or bucket. In
addition,
with the very large facilities that are becoming quite common in modern dairy
farming,
sometimes with an overall length in excess of 1000 feet, the quantity of
accumulated
material is too great to transfer to one end of the facility. As a result,
there is a need
for improvements in the collection and removal of manure from animal husbandry
facilities.
[0003] Pneumatic collection of agricultural debris is used in a variety of
operations both on and off the farm. For example, in the clean-up of spills of
dry solid
materials, such as grain or agricultural chemicals like fertilizer, vacuums
are employed
to pneumatically transfer the spilled materials to a storage container. An
example of
such a vacuum apparatus is provided in United States patent 4,218,226. These
types
of machines are not particularly well-suited to the collection of liquid or
semi-liquid
materials such as animal waste. Moreover, they lack any type of collection
means for
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mounting beneath the apparatus to direct the collected material to the suction
inlet
when the apparatus is driven over the material, making them difficult to use
in large
scale mobile cleanup operations.
[0004] Vacuum systems have been used for mobile cleanup of relatively dry
manure, such as chicken and horse manure. United States patent 5,010,620
discloses a stall and pasture vacuum machine that includes a front mounted
sled
comprising a rotary brush. A mist of water may be provided to soften the
manure and
make it more amenable to pneumatic conveying. The collected manure is stored
in a
dump box with a hinged rear door. This machine is not suitable for the cleanup
of
liquid or semi-liquid materials.
[0005] Vacuum systems have been used in the clean-up of liquid and semi-
liquid animal waste. United States patent 3,585,670 discloses an apparatus
comprising a vacuum tank and a rear-mounted V-shaped scraper blade. However,
in
mounting the scraper blade at the rear of the apparatus, the manure is
compacted
prior to being collected, making it difficult to separate from the barn floor
and difficult to
convey pneumatically.
[0006] Another vacuum apparatus for the collection of liquid or semi-liquid
manure is manufactured by Loewen Welding & Manufacturing (Matsqui, BC, Canada)
under the trade-name Honey-Vac . In this apparatus, the collected manure
enters the
back of the vacuum tank from the top thereof. Since the collected manure is
also
discharged from the back, there is no complete flushing from front to rear
during
discharge. This leads to an accumulation of manure in the front of the tank
that
diminishes tank capacity after repeated use. The accumulated manure must be
periodically cleaned out through manual access hatches, which is a dangerous
and
unpleasant task. Also, the apparatus makes use of separate blower and vacuum
pumps, which creates mechanical complexity and increases down time.
[0007] As a result, there remains a need for an improved material collection
apparatus, particularly for liquid and semi-liquid materials such as animal
manure.
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Summary of the Invention
[0008] According to an aspect of the present invention, there is provided a
mobile vacuum apparatus for collection of liquid or semi-liquid materials, the
apparatus
comprising: a frame having a front and rear; a set of wheels mounted under the
frame;
a vacuum tank for receiving collected liquid or semi-liquid materials, the
vacuum tank
having a vacuum inlet at a front thereof and a vacuum outlet at a top thereof;
a
collection means comprising a scraping element mounted under the front of the
frame,
the collection means in fluid communication with the vacuum inlet; a discharge
outlet
at a rear of the tank; and, a blower vac capable of drawing air from the
vacuum tank
through the vacuum outlet to thereby create a vacuum in the tank.
[0009] According to another aspect of the invention, there is provided a
mobile
vacuum apparatus for collection of liquid or semi-liquid materials, the
apparatus
comprising: a frame having a front and rear; a set of wheels mounted under the
frame;
a vacuum tank for receiving collected liquid or semi-liquid materials, the
vacuum tank
having a vacuum inlet at a front thereof and a vacuum outlet at a top thereof;
a
collection means in fluid communication with the vacuum inlet; a discharge
outlet
rearward of the collection means; a blower vac selectively capable of either
drawing air
from the vacuum tank through the vacuum outlet to thereby create a vacuum in
the
tank or blowing air into the vacuum tank to thereby expel the collected liquid
or semi-
liquid materials therefrom under pressure through the discharge outlet; and, a
valve
means for directing air to a blower vac exhaust when drawing air from the
vacuum
tank and for supplying air from an elevated blower vac intake when blowing air
into the
vacuum tank.
[0010] The apparatus is mobile and may be either pulled by a towing vehicle or
self-propelled. The towing vehicle may be a farm tractor and the apparatus is
particularly suitable for agricultural use. The apparatus is designed to be
driven over
the material to be collected with the collection means in front to reduce
compaction of
the material being collected. The material being collected may be any type of
liquid or
semi-liquid material suitable for pneumatic conveying. The material may
comprise
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liquid waste. The material may comprise animal manure, such as manure from
cows
or pigs, and the animal manure may be in a semi-liquid state. The apparatus
may be
adapted for use in an animal husbandry facility, such as a dairy barn or
milking shed,
particularly such a facility that includes alleys or gutters for collection of
manure.
[0011] It is desirable that the collected material is prevented from entering
the
blower vac, as obstruction of its internal moving parts can cause significant
damage to
the blower vac. The vacuum tank includes a vacuum outlet that may comprise two
or
more vacuum outlets spaced apart along the top of the tank. By using two or
more
vacuum outlets, the velocity through each outlet is decreased, thereby
reducing the
likelihood that the collected material can become entrained in the air flowing
through
the outlets. The outlets may be of the same size or different sizes in order
to
preferentially direct the collected material to different parts of the tank.
Each outlet
may include a primary trap to further reduce the likelihood of material
escaping
through the vacuum outlet, particularly when the tank is full. Any suitable
primary trap
design may be used and the primary trap is preferably readily cleaned by
reducing the
air flow through the vacuum outlet.
[0012] Air flowing from the vacuum outlet may be directed to a secondary trap
for yet further reducing the likelihood that entrained debris will enter the
blower vac.
The secondary trap may be of any suitable design and may comprise a chamber
containing a series of baffle plates that are arranged to create a serpentine
path.
Alternatively, the chamber may contain a plurality of perforated impingement
plates
stacked with the perforations in an offset relationship. The secondary trap
may be
similar to a knock-out pot in that it may be designed for the removal of
liquid from the
air flow, particularly liquid droplets. The secondary trap may be cleaned by
reversing
the direction of air flow through the trap and may be additionally or
alternatively
cleaned using a supplemental stream of air or water to flush out the contents
of the
trap. The secondary trap may include a drain and the drain may be directed
back into
the vacuum tank. The outlet of the secondary trap is preferably free of
collected
material or droplets and is provided to the blower vac.
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[0013] The blower vac may be powered by a motor of the towing vehicle or by a
motor mounted on the apparatus itself. A separate motor may be used to
independently power the blower vac. The towing vehicle may be connected to the
blower vac using a power take-off (PTO) mechanism. The blower vac may comprise
a
single unit or two separate but connected units. The blower vac may comprise
two
chambers connected to a single power source. The blower vac may comprise an
internal valve that permits the flow path through the blower vac to be altered
in order to
switch the intake port of the blower vac to the exhaust port and vice versa.
The blower
vac may be reversible in order to alternate intake and exhaust ports. The
blower vac
may comprise a positive displacement pump, such as a rotary vane pump. The
blower
vac may be in fluid communication with a valve means.
[0014] The valve means may be used as part of any liquid or semi-liquid
material collection system that both draws and expels material pneumatically.
The
valve means may be automatically adjustable or manually adjustable. The valve
means may comprise a three-way valve mechanism that permits selection of a
single
flow path from two different flow paths, for example and L-ported ball valve
that may
be alternated between two flow paths. The valve means may comprise a pair of
check valves, one check valve in each of the intake and exhaust flow paths.
The
check valves may be oppositely oriented to permit air to flow into the valve
means
through only one flow path (the intake flow path) and out of the valve means
by only
the other flow path (the exhaust flow path). In this manner, the valve means
is
automatically adjustable in response to a change in the direction of flow
through the
blower vac. The valve means may include a valve chamber and the check valves
need not necessarily both be located in the valve chamber. The valve means is
particularly advantageous in allowing an air intake and exhaust of the system
to be
separated, thereby permitting the intake to be elevated with respect to the
material
being collected and the exhaust to be located distantly from the operator. The
elevated exhaust reduces the likelihood of debris entering the blower vac when
blowing air into the tank and the distant exhaust improves operator health and
safety.
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[0015] The collection means may be any suitable mechanism for directing the
material toward the pneumatic collection inlet and may include, for example a
brush,
rotating brush, scraper, squeeqee, air blast, water jet, or a combination
thereof. The
scraper may comprise a scraping element made from a rigid yet flexible
material, such
as a high durometer or reinforced rubber. The collection means may be height
adjustable and may be either self-leveling or manually level adjusted with
respect to
the material collection surface. The suction inlet of the pneumatic collection
system
may be through a distribution means to permit collection across the width of
the
collection means or collection may occur at a discrete point or points. The
collection
means may have a shape adapted for funneling the material toward the suction
inlet,
for example a V-shape when seen in plan view.
[0016] The suction inlet may be height adjustable independently of any height
adjustment of the collection means in response to the quantity of material
being
collected; this permits a scraping element of the collection means to remain
in contact
with the floor surface while allowing the suction inlet to be adjusted
relative in height
thereto in response to a large quantity of material being collected. Any
suitable
mechanism may be employed to adjust the height of the suction inlet. The
suction
inlet is preferably connected to the vacuum inlet by a flexible connection in
order to
facilitate the height adjustment. By setting the suction inlet closer to the
floor surface
that the material is being collected from more material may be collected,
thereby
leaving less material in the collection means at the end of a pass through an
alley.
However, if set close to the floor, the suction inlet will have more material
to pick-up
and driving speed may have to be reduced. There is therefore an optimal trade-
off
between speed and completeness of collection. A snorkel may be provided
alongside
the suction inlet for introducing a small quantity of air into the material as
it is being
collected. This small quantity of air is entrained with the material and makes
it easier
to lift from the floor and easier to pneumatically convey, particularly for
materials with a
thick consistency. The snorkel may include a small valve to set the quantity
of air
provided to the suction inlet according to the consistency of the material
being
collected.
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[0017] The collection means may include a variable width mechanism. The
variable width mechanism is particularly useful in the collection of manure
from alleys
or gutters, as it allows the collection means to fit the width of the alley or
gutter and
reduces the likelihood of manure escaping around the sides of the collection
means.
The collection means may include wings that are pivotally attached to each
side of the
collection means and able to pivot about a vertical pivot axis. The wings may
be
biased outwardly towards or against the sidewalls of the alley or gutter and
may
resiliently adapt to changes in the width of the gutter by pivoting about the
vertical
pivot axis. The wings may move about the vertical pivot axis in response to a
change
in the distance between the side-wall of the alley and the collection means.
The wings
may be biased by a spring means or a suitable fluid cylinder arrangement, such
as a
pneumatic or hydraulic fluid displacement cylinder, a captive gas shock
absorber, or a
combination thereof. The wings may automatically adjust to the width of the
alley or
gutter or may be manually adjusted by an operator of the apparatus. The
adjustment
may be conducted using controls within the towing vehicle. The wings may
include
skid plates or wear strips to reduce the likelihood of damaging the wings due
to
operator driving error.
[0018] The discharge outlet is provided at the rear of the vacuum tank. The
discharge outlet may be connected to any manure distribution system suitable
for
liquid or semi-liquid manure, such as a spreader plate or sub-surface
injection system.
Alternatively, the discharge outlet may be connected via a fluid conduit for
transferring
the manure to a separate spreading apparatus or a holding vessel. The vacuum
inlet
is provided at the front of the tank, preferably in a lower half thereof below
the
horizontal midline of the tank. Filling the tank from the front and
discharging the tank
through the rear causes a flushing of the collected materials through the
tank. This
causes substantially all of the material in the tank to be discharged and
mitigates
material build-up in the front of the tank. During collection, a remotely
operable valve
on the discharge outlet is closed to prevent inadvertent leakage from
occurring.
During tank discharge, a remotely operable valve on the vacuum inlet is closed
to
prevent material from being discharged through the collection means.
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[0019] Further features of the invention will be described or will become
apparent in the course of the following detailed description.
Brief Description of the Drawings
[0020] In order that the invention may be more clearly understood,
embodiments thereof will now be described in detail by way of example, with
reference
to the accompanying drawings, in which:
[0021] Fig. 1 a is a side view of the apparatus according to the present
invention
showing a flow path through the apparatus when material is being collected;
[0022] Fig. 1 b is a side view of the apparatus according to the present
invention
showing a flow path through the apparatus when material is being discharged;
[0023] Fig. 2 is a side view of an embodiment of a collection means according
to the present invention;
[0024] Fig. 3 is a top view of the collection means of Fig. 2;
[0025] Fig. 4 is a side view of the height adjustable suction inlet of the
present
invention;
[0026] Fig. 5a is a schematic side view of the valve means of the present
invention while air is being drawn from the vacuum tank;
[0027] Fig. 5b is a schematic side view of the valve means of the present
invention while air is being blown into the vacuum tank;
[0028] Fig. 6 is a perspective view of another embodiment of a collection
means
according to the present invention;
[0029] Fig. 7a is a front view of the collection means of Fig. 6;
[0030] Fig. 7b is a bottom view of the collection means of Fig. 6; and,
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[0031] Fig. 8 is a bottom perspective view of a rotary feeder for the
collection
means of Fig. 6.
Description of Preferred Embodiments
[0032] In describing the figures, like features are referred to by like
reference
numerals. Although not all features indicated on a particular drawing are
necessarily
described with reference to that drawing, all of the features are described
with
reference to at least one of the drawings.
[0033] Referring to Figs. 1 a and 1b, the mobile vacuum apparatus comprises a
vacuum tank 1 mounted on a frame 2 having a front and rear with a hitch means
3 for
connection to a towing vehicle (not shown) at the front of the frame. A
collection
means 4 is mounted to the underside of the frame 2 at the front thereof,
forward of a
discharge outlet 5 of the vacuum tank 1. A spreader means 6 is attached to a
flange
on the discharge outlet 5. A set of tandem wheels 8 is mounted to the
underside of
the frame 2 using a walking-axle arrangement as is conventionally known.
[0034] A blower vac 7 is provided at the front of the frame 2. The blower vac
7
is a positive displacement rotary vane pump (in a preferred embodiment, a
Wallenstein
type pump) that can operate as either a blower or vacuum pump. The blower vac
7 is
a single integrated unit capable of selectively drawing air from the vacuum
tank or
blowing air into the vacuum tank. An integral valve (not shown) is provided as
part of
the blower vac 7 to switch between drawing air from and blowing air into the
vacuum
tank 1. The pump derives power from the towing vehicle via a PTO shaft 15.
[0035] Fig. la schematically shows a flow path through the apparatus when
material is being collected. The collection means 4 is lowered with respect to
ground
level and parallel thereto with a scraper element 14 in contact with the floor
surface.
Material is admitted into a suction inlet (not shown in Figs la and 1b) of the
collection
means 4 and drawn through suction conduit 37 into vacuum inlet 16 of vacuum
tank 1.
The vacuum inlet 16 is located on the front of the vacuum tank 1 in the lower
half
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thereof below the horizontal midline of the tank. This causes the collected
material to
fill the tank from front to rear, improving weight distribution and
facilitating substantially
complete discharge. The air is then drawn out of the vacuum tank 1 through
vacuum
outlet 17, which comprises front vacuum outlet 17a and rear vacuum outlet 17b.
The
use of two vacuum outlets 17a and 17b reduces the exit air velocity by half as
compared with a single outlet, significantly reducing the likelihood of debris
becoming
entrained and exiting through the vacuum outlet 17. Each vacuum outlet 17a and
17b
is equipped with a primary trap 23 comprising a stainless steel ball float 18
captivated
within a rigid mesh cage 19. The rigid mesh cage 19 helps prevent material
from
exiting the tank 1 through the vacuum outlet 17. As the level of material in
the vacuum
tank 1 rises to the top of the tank, the float 18 rises and blocks the outlet
17 to prevent
material from being drawn out of the tank. The primary trap 23 therefore
serves as a
first line of defense in keeping the collected material within the tank 1.
[0036] Air drawn through the vacuum outlet 17 is next directed into secondary
trap 21 at the bottom thereof. The secondary trap 21 includes a plurality of
stacked
baffles 22 arranged to create a serpentine flow path through the trap 21. This
causes
disengagement of any materials entrained in the air flow, particularly liquid
materials
which may have passed the mesh cage 18 of the primary trap 23. The secondary
trap
21 includes a drain (not shown) for re-introducing any collected material back
into the
vacuum tank 1. The secondary trap 21 may be cleaned using supplementary flows
of
water or air provided through ports (not shown) at the top thereof. The exit
of the
secondary trap 21 is protected by a stainless steel ball float 18 captivated
within a rigid
mesh cage 19 in an arrangement similar to that of the primary trap 23.
[0037] Air exiting the secondary trap 21 is provided to the blower vac 7
through
first blower vac conduit 24 and exits therefrom through second blower vac
conduit 26.
The air is provided to a valve means comprising a valve chamber 50 and
pressurizes
the valve chamber, causing the second closure means 60 to open and allowing
the air
to exit through the anterior end of blower vac exhaust 52.
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[0038] In Fig 1b, the apparatus is illustrated in a tank discharge condition.
The
blower vac 7 creates a negative pressure or vacuum in the valve chamber 50.
This
causes the first closure means 54 to open, admitting air into the valve
chamber 50
through blower vac intake 51. The air then flows through the second blower vac
conduit 26 into the blower vac 7, which acts to blow the air out through first
blower vac
conduit 25. The air flows downwardly through the secondary trap 21, back
flushing
any accumulated debris out through the drain (not shown) and into tank 1. The
air
then passes out of the bottom of the secondary trap 21 and into the vacuum
outlet 17
at the top of the vacuum tank 1. The primary trap 23 is back flushed to
dislodge any
debris accumulated against the mesh cage 19. A positive pressure is created in
the
vacuum tank 1, which forces the collected material outwardly through rear
discharge
outlet 5. A remotely operable discharge valve (not shown) is opened during
discharge
to allow material to exit through the spreader means 6 and is closed during
collection
of material. Conversely, a remotely operable suction valve (not shown) is
closed
during tank discharge to prevent material from exiting through the collection
means 4
and is opened during collection of material.
[0039] The introduction of air through the first vacuum outlet 17a causes
material accumulated at the front of the tank to be pushed downwardly and out
through the discharge outlet 5. In this manner, a complete flushing of the
vacuum tank
1 occurs to expel substantially all of the material in the tank (as compared
with prior art
systems) reducing the need for manual cleanout of the front of the vacuum
tank.
[0040] Referring to Figs. 2 and 3, the collection means 4 is pivotally mounted
to
the underside of the frame 2 by way of pivot arm 10. Pivot arm 10 is pivotally
attached
at one end to a central portion 29 of the collection means 4 at first pivot
pin 27 and at
the other end to the frame 2 at second pivot pin 28, which is located between
the
tandem wheels 8. A hydraulic lift cylinder 9 is provided between the central
portion 29
and the frame 2 and may be extended or retracted to lower or raise,
respectively, the
collection means 4 by pivoting of the pivot arm 10 about the second pivot pin
28. The
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collection means 4 is typically raised when turning the apparatus to prevent
damage to
the collection means due to skid-induced lateral forces.
[0041] An adjustable length link 11 is pivotally attached at one end to an
upwardly extending stub 12 fixedly mounted on the pivot arm 10. The other end
of the
link 11 is pivotally attached to the central portion 29 at link pivot 13,
which is located
above the first pivot pin 27. By adjusting the length of the link 11, a fine
tilting
adjustment of the central portion 29 may be attained so as to ensure that the
scraper
element 14 attached to the underside of the collection means 4 remains in
contact with
the floor or other surface from which the materials are being collected. The
scraper
element 14 comprises a high durometer rubber scraping edge with a steel
reinforcement. This permits the scraping element 14 to conform somewhat to
irregularities in the scraped surface while providing sufficient rigidity to
remove
adherent materials. The rubber scraping edge also provides a squeegee effect
similar
to an automotive windshield wiper that permits liquid or semi-liquid materials
to be
scraped.
[0042] The collection means 4 further comprises a pair of laterally adjustable
wings 30 that are attached to the central portion 29 on opposite sides
thereof. Each
wing 30 is pivotally attached to the central portion 29 using a piano hinge 31
that
allows the wing to pivot about a vertical pivot axis passing through the
center of the
hinge. A hydraulic wing cylinder 32 is pivotally attached to each wing 30 and
to central
portion 29 so that extension of the wing cylinders causes the wings to open,
thereby
increasing the width of the collection means 4. The wings 30 are closed by
retracting
the wing cylinders 32. The normal range of movement of the wings 30 is from a
closed
position parallel to the longitudinal axis of the apparatus (defined by its
direction of
travel) to an open position which is at an angle less than perpendicular to
the
longitudinal axis and preferably tangential to the central portion 29 at the
hinges 31.
Fig. 3 shows the closed position (marked A) and also shows the open position
(marked B) in phantom lines. In the open position, the wings 30 extend past
the
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wheels 8. The wings 30 are normally closed when transporting the apparatus to
reduce the risk of damaging the wings.
[0043] The wings 30 may be controlled using a single circuit so that they both
open and close at the same time or using separate circuits so that one or the
other of
the wings may be opened or closed. In addition, the wings 30 need not be
completely
opened, but can be set to any desired angle of opening. This is particularly
advantageous when scraping a large area without side-walls. When scraping an
alley
or gutter with side-walls, such as in an animal husbandry facility, the wings
30 are
preferably opened until a skid protector 33 attached to the distal end of each
wing
comes into contact with the side-wall. The skid protector 33 may be made from
metal
or a durable plastic, preferably a plastic with dry lubricant qualities such
as Delrin . A
pressure relief valve (not shown) is provided in each hydraulic circuit of the
wing
cylinders 32 in order to permit the wings 30 to close by rotating about the
vertical pivot
axis in response to a decrease in distance between the collection means 4 and
the
side-wall. The valves may be adjusted to maintain a modest cylinder extension
pressure so that the wings 30 return to the desired pre-set open position when
the
distance between the collection means 4 and the side-wall increases. The net
effect is
that closing of one wing 30 due to distance changes while driving is matched
by a
corresponding opening of the opposite wing.
[0044] A height adjustable suction inlet 20 is provided at about the center of
the
central portion 29. Referring to Fig. 4, the suction inlet 20 has a 450 bend
so that a
lower portion 34 forms a downwardly oriented nozzle opening 35 that is roughly
parallel with the floor (subject to fine level adjustment using adjustable
length link 11).
The upper portion 36 of the suction inlet 20 is attached one end of flexible
suction
conduit 37. The other end of suction conduit 37 is attached to the vacuum
inlet 16 of
vacuum tank 1. The flexible suction conduit 37 permits the height of the
suction inlet
20 to be adjusted without constraint by the conduit. An upright post 38 is
fixedly
attached to the suction inlet 20. The central portion 29 has an inverted L-
shaped
cross-section with a top portion 39 to which a collar 40 is mounted. The
collar 40 is
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forwardly offset from the central portion 29 and has a bore that is
complementary in
size to the upright post 38. The bore permits sliding passage of the upright
post 38
through the collar 40. A user-adjustable set screw 41 is provided in the
collar 40 for
threading engagement with the upright post 38. By loosening the set screw 41,
the
upright post 38 is permitted to slide through the bore of the collar 40,
allowing the
height of the suction inlet 20 to be raised or lowered relative to ground
level.
Tightening the set screw 41 allows the desired height of the suction inlet 20
to be
fixed. During forward travel of the apparatus in the direction indicated by
arrow C, the
liquid or semi-liquid material being collected accumulates within the inverted
L-shaped
cross section of the central portion 29 and is constrained from overflowing by
the top
portion 39 thereof. The height of the suction inlet 20 is typically adjusted
higher for
thick semi-liquid materials and lower for liquid materials. In an alternative
embodiment, the height of the suction nozzle may be adjusted by an operator
within a
tractor or towing vehicle using hydraulic controls.
[0045] A snorkel 43 is provided alongside the suction inlet 20. The snorkel 43
permits a small quantity of air to be introduced into the opening 35 for
entrainment with
the materials being collected by the suction inlet 20. It has been found that
the
introduction of air by the snorkel 43 is of particular use in the collection
of thick semi-
solid materials, as the two-phase flow produced tends to aid in pneumatically
conveying the materials into the vacuum tank 1. A snorkel valve 44 may be
adjusted
to deliver the desired amount of air to the suction inlet 20 according to the
consistency
of the materials being collected.
[0046] Referring to Figs. 5a and 5b, a valve means is schematically shown as
part of the blower vac intake/exhaust system. A valve chamber 50 is provided
with an
elevated blower vac intake 51 extending upwardly therefrom and a blower vac
exhaust
52 extending downwardly therefrom. The second blower vac conduit 26 extends
from
the side of the valve chamber 50 and permits flow in either direction between
the
blower vac 7 and the valve chamber. The second blower vac conduit 26 is
preferably
provided tangentially to the valve chamber 50 and laterally offset from the
vertical
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centerline thereof to create a swirling flow pattern and cyclonic action
within the valve
chamber. The valve chamber 50 can be shaped and/or include supplementary flow
elements to enhance this flow pattern. The cyclonic action is used as an aid
in
removing dust or debris when the blower vac intake 51 is being used to supply
air for
blowing into the vacuum tank 1.
[0047] Fig. 5a shows the valve means in operation when drawing air from the
vacuum tank 1. A first closure means 54 is pivotally attached to the lower end
of the
blower vac intake 51 within the valve chamber 50 by closure hinge 55. The
first
closure means 54 has a counterweight 56 on an opposite side of the closure
hinge 55
from the blower vac intake 51. The counterweight 56 biases the first closure
means
54 into a closed position to seal the end of the blower vac intake 51. The
valve
chamber 50 is pressurized when air is drawn from the vacuum tank 1 and the air
pressure helps maintain the first closure means 54 in a closed position. The
pressurized air escapes through blower vac exhaust 52. The blower vac exhaust
52 is
downwardly oriented from the valve chamber 50 and is routed along the
underside of
the frame 2. An opening at the anterior end of the blower vac exhaust 52
directs the
foul-smelling air drawn from the vacuum tank 1 downwardly and away from the
operator of the apparatus, who is located in the towing vehicle attached to
the front
hitch means 3. This improves the overall health and safety of the operator. A
second
closure means 60 is pivotally attached to the anterior end of the blower vac
exhaust
52. A closure weight 61 is provided to bias the second closure means 60 into a
closed
position over an opening in the anterior end of the blower vac exhaust 52.
However,
the flow of pressurized air provided from the valve chamber 50 is sufficient
to
overcome this bias and causes the second closure means 60 to open, thereby
allowing air to escape through the opening.
[0048] Referring to Fig. 5b, the valve means is shown in operation during tank
discharge when the blower vac 7 is used to blow air into the vacuum tank 1.
The flow
path through the second blower vac conduit 26 is reversed as compared with
Fig. 5a
and the valve chamber 50 is under vacuum. The vacuum overcomes the bias
CA 02673155 2009-07-20
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provided by the counterweight 56 and causes the first closure means 54 to
open,
admitting air into the valve chamber 50 through the blower vac intake 51. A
filter 59 is
provided atop the blower vac intake 51 to remove debris from the intake air
stream in
order to reduce the potential for damage to the blower vac 7. The negative
pressure
within the valve chamber 50 enhances the bias on the second closure means 60
provided by the closure weight 61 and acts to seal the blower vac exhaust 52.
[0049] By referring to Figs. 5a and 5b, it can be seen that the first and
second
closure means 54 and 60 of the valve means act as oppositely oriented check
valves
that permit flow in only one direction through each of the blower vac intake
51 and
blower vac exhaust 52. The valve means permits flow through one flow path or
the
other, depending on the direction of flow through the second blower vac
conduit 26.
The first and second closure means 54 and 60 automatically close or open
according
to whether air is being drawn from the vacuum tank 1 or blown into the vacuum
tank 1.
[0050] Referring to Figs. 6 and 7a-b, an alternative embodiment of a
collection
means for use with the mobile vacuum apparatus is shown. The central portion
29 of
the collection means comprises two forward angled sides 70. Each of the sides
70
has a scraper element 14 located at a bottom thereof for accumulating the
liquid or
semi-liquid materials within an interior 71 of the central portion 29 when the
apparatus
is in use. The forward angled sides converge at an apex 72 such that the
central
portion 29 appears substantially V-shaped when seen in top view. In another
alternative embodiment, the central portion 29 appears trapezoidal when seen
in top
view. The suction inlet 20 is located at a middle of the central portion 29,
adjacent the
apex 72. In order to prevent the collected materials from overflowing the
interior 71,
the central portion 29 is provided with a top flange 73, which causes it to
have the
aforementioned inverted L shaped vertical cross-section. The wing cylinders 32
are
pivotally mounted to the top flange 73 in order to permit the wings 30 to
pivot about the
piano hinge 31 as previously described. Each wing is equipped with a scraper
element 14 at a bottom thereof and a skid protector 33, as previously
described, to
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NUN-0002-CA2 17
permit the wings to open in order to vary the width of the collection means 4
to match
the width of the alley or gutter being scraped.
[0051] During the collection of certain semi-liquid materials, particularly
those
with a thick and/or sticky consistency, there can be a tendency for
accumulation to
occur along the scraper element, thereby interfering with proper operation of
the
vacuum apparatus. To help mitigate this problem, the collection means 4 is
provided
with a plurality of rotary feeders 74 located adjacent the scraper element
within the
interior 71. Preferably, there is at least a rotary feeder 74 provided on
either side of
the suction inlet 20. More preferably, there is at least a rotary feeder 74
provided on
either side of the suction inlet 20 and at least a rotary feeder 74 provided
on each wing
30.
[0052] Referring additionally to Fig. 8, each rotary feeder 74 is equipped
with a
hydraulic motor 77 mounted atop a feeder mounting bracket 79. The hydraulic
motor
77 is mounted to provide a vertical axis of rotation 78. A set of radially
extending
protrusions 75 concentric with the axis 78 is mounted to the output shaft of
the motor
77 below the bracket 79. The protrusions 75 are substantially scoop shaped,
curving
away from the direction of rotation of the motor 77, although need not
necessarily be
so. Each protrusion 75 is rigid and equipped with a downwardly extending lip
76 on
the bottom thereof. Use of an independent hydraulic motor 77 for each rotary
feeder
74 allows the rotational speed of each feeder to be adjustable, if so desired.
The
rotational speed is determined according to the consistency of the materials
being
collected, the height of the suction inlet 20 and/or the rate of travel of the
mobile
vacuum apparatus. The rotational speed may be adjusted by an operator of the
tractor used to pull the apparatus; for example, one, two or more sets of
hydraulic
remotes may be employed and the speed of the connected motors may be adjusted
using a control lever located in the tractor. Two or more motors may be
connected in
parallel to a set of hydraulic remotes. In one embodiment, the rotational
speed of the
rotary feeders 74 on the wings 30 is separately adjustable from the rotational
speed of
the rotary feeders 74 on the central portion 29, since more material
accumulates near
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the apex 72 and hence a higher speed is sometimes needed for the feeders 74
closest
to the suction inlet 20.
[0053] Referring particularly to Fig. 7a, it is important to note that the
height of
the rotary feeders 74 is elevated with respect to ground level, typically by
an amount of
from 1 to 2 inches. In other words, the rotary feeders are not in contact with
the
ground, nor with the scraper element 14. The feeders 74 simply function to
reduce
accumulation of material adjacent the scraper element 14 by mixing thinner
material
with thicker material in order to make it more amenable to scraping. In the
event that a
significant amount of material does accumulate, the feeders 74 dislodge the
material in
order to transfer it towards the apex 72.
[0054] Other advantages which are inherent to the structure are obvious to one
skilled in the art. The embodiments are described herein illustratively and
are not
meant to limit the scope of the invention as claimed. Variations of the
foregoing
embodiments will be evident to a person of ordinary skill and are intended by
the
inventor to be encompassed by the following claims.
