U.S. patent number 3,858,358 [Application Number 05/320,279] was granted by the patent office on 1975-01-07 for high pressure liquid and abrasive cleaning apparatus.
This patent grant is currently assigned to American Aero Industries, Inc.. Invention is credited to John B. Goss, John E. Stachowiak.
United States Patent |
3,858,358 |
Stachowiak , et al. |
January 7, 1975 |
HIGH PRESSURE LIQUID AND ABRASIVE CLEANING APPARATUS
Abstract
A high pressure cleaning apparatus including a blasting nozzle
for separately directing a liquid and gas-abrasive mixture
outwardly toward an object being cleaned; and, pumping apparatus
for pumping liquid and a gas-abrasive mixture to the blasting
nozzle, the blasting nozzle including mixing means for mixing the
liquid with the gas-abrasive mixture outwardly of the nozzle for
propelling the gas-abrasive mixture at high velocity and pressure.
Control means operable at the nozzle are provided for controlling
the flow of liquid and gas-abrasive mixture to the nozzle.
Inventors: |
Stachowiak; John E. (Houston,
TX), Goss; John B. (Houston, TX) |
Assignee: |
American Aero Industries, Inc.
(Houston, TX)
|
Family
ID: |
23245692 |
Appl.
No.: |
05/320,279 |
Filed: |
January 2, 1973 |
Current U.S.
Class: |
451/90;
451/99 |
Current CPC
Class: |
B24C
3/02 (20130101); B24C 7/0053 (20130101); B24C
7/0076 (20130101) |
Current International
Class: |
B24C
7/00 (20060101); B24C 3/00 (20060101); B24C
3/02 (20060101); B24c 003/00 () |
Field of
Search: |
;51/8,11,12 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Kelly; Donald G.
Assistant Examiner: Davidson; Marc R.
Claims
We claim:
1. A liquid-abrasive cleaning apparatus, comprising:
a blasting nozzle for separately directing liquid and a
gas-abrasive mixture exclusive of any liquid outwardly toward an
object for cleaning same;
a liquid supply connected with said nozzle and liquid pump means
for pumping said liquid outwardly of said blasting nozzle at a high
blast pressure;
a gas supply and an abrasive supply connected with said nozzle, and
compressor means for mixing abrasive with gas and for pumping a
gas-abrasive mixture outwardly of said blasting nozzle at a lower
pressure than said high blast pressure; and
said blasting nozzle including a central, low pressure, nozzle
portion in fluid communication with said gas-abrasive mixture, said
gas-abrasive mixture being directed outwardly of said central
nozzle portion in a low-velocity stream; and
said blasting nozzle further including a plurality of
circumferentially spaced, high pressure nozzle portions positioned
about said central nozzle portion, each of said circumferentially
spaced nozzle being in fluid communication with said high pressure
liquid and directing outwardly, separately from said gas-abrasive
mixture, high velocity liquid toward said low-velocity,
gas-abrasive stream whereby said gas-abrasive mixture is propelled
to said object with said high-velocity blasting water.
2. The structure set forth in claim 1, wherein:
each of said circumferentially spaced nozzle portions has an axis
which intersects the axis of said central nozzle portion at an
acute angle.
3. The structure set forth in claim 1, wherein said
circumferentially spaced nozzle portions include:
a first set of circumferentially spaced nozzles having axes which
intersect the axis of said central nozzle at a first angle; and
a second set of circumferentially spaced nozzles having axes which
intersect the axis of said central nozzle at a second angle.
4. A water-abrasive cleaning device, comprising:
a blasting nozzle for separately directing water and an
air-abrasive mixture exclusive of any liquid outwardly toward an
object for cleaning same, said blasting nozzle being adapted for
connection to a supply of low pressure, air-abrasive mixture supply
and to a high pressure water supply;
said blasting nozzle includes a central, low pressure, nozzle
portion in communication with said low pressure air-abrasive
mixture supply, said air-abrasive mixture being directly outwardly
of said nozzle in a low-velocity stream; and
said blasting nozzle further including a plurality of
circumferentially spaced, high pressure nozzle portions positioned
about said central nozzle portion, being in communication with said
high pressure water supply and directing high velocity water toward
said low-velocity, air-abrasive stream whereby said air-abrasive
mixture is propelled to said object with said high-velocity
blasting water.
Description
BACKGROUND OF THE INVENTION
The field of this invention is high pressure cleaning
apparatus.
A disadvantage of sand-blasting equipment that provides a blasting
stream of air and sand is the undesirable dispersion of sand and
dust from the object being cleaned into the atmosphere in the
vicinity of the equipment. Some nozzles for blasting equipment mix
water and sand inside the nozzle to provide a blasting stream
containing water for at least partly preventing dispersion of the
sand and abrasive dust. For example, see U.S. Pat. Nos. 2,290,979
and 2,325,517. One of the disadvantages of such nozzles is the
tendency of the nozzles to wear excessively due to the passage
through the nozzle of the sand and water mixture.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a new and improved
high pressure, water-abrasive cleaning apparatus which provides a
high velocity, high pressure blasting stream that cleans an object
faster and more efficiently without polluting the atmosphere with
abrasive dust. The high pressure cleaning apparatus of the
preferred embodiment of this invention includes a blasting gun
having a blasting nozzle mounted thereon for separately directing
outwardly therefrom a low velocity stream of an air-abrasive
mixture and a high velocity stream of water. Peripheral water
nozzles are mounted in the blasting nozzle in position to converge
streams of water into a central stream of air-abrasive mixture so
that the high velocity, high pressure water stream propels the
air-abrasive mixture to the object being cleaned. The high pressure
cleaning apparatus includes pumping means for pumping water at a
high pressure and an air-abrasive mixture at a low pressure.
The blasting gun is connected by hoses to the pumping apparatus
such that the blasting gun may be freely moved about and electric
control means are mounted with the blasting gun for remotely
operating the pumping apparatus. The electric control means
includes means for reducing the water supplied to the nozzle to a
minimal flow and means for shutting off the flow of
air-abrasive.
A corrosion-inhibitor fluid supply is connected with the pumping
apparatus and is controlled by the electric control means such that
corrosion-inhibitor can be injected into the high pressure water
for coating the blasted object after such object has been
cleaned.
The peripheral water nozzles include both long and short range sets
of water nozzles that direct the water into convergence with the
air-abrasive mixture. The long range peripheral water nozzles have
axes which intersect the axis of the central nozzle at an angle
which is less than the angle of intersection of the axes of the
short range water nozzles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of the high pressure, water abrasive
cleaning apparatus of the preferred embodiment of this
invention;
FIG. 2 is a side view in section of the blasting nozzle of this
invention illustrating the angular disposition of the short range
peripheral water nozzles;
FIG. 3 is a front view of the blasting nozzle; and
FIG. 4 is a side view of the blasting nozzle illustrating
schematically the angular disposition of the long range set of
peripheral water nozzles.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, the letter H generally designates a high
pressure, water-abrasive cleaning apparatus for providing a high
velocity blasting stream 10 for the impact cleaning of an object.
The high pressure cleaning apparatus includes a blasting gun 11
having blasting nozzle 12 mounted thereon for directing separate
streams of an air-abrasive mixture and water outwardly of the
nozzle. The blasting gun 11 includes a handle 11a and a shoulder
brace 11b which allows the operator to firmly grip and control the
blasting gun during use. Electrical control means 14 including
trigger switches 14a and 14b are mounted onto the blasting gun at
the handle 11a.
The blasting gun 11 includes a water conduit 11c that is attached
to the nozzle 12 and an air-abrasive conduit 11d also attached to
the nozzle 12. The conduits are supported by bracket portion 11e so
that the entire blasting gun can be moved as a unit. The handle 11a
is actually mounted onto the water conduit 11c.
The blasting gun 11 is connected by flexible hoses 15 and 16 to a
pumping station generally designated by the number 20. The pumping
station includes a water pump 21 which is driven by engine 22 as
illustrated schematically in FIG. 1. A water supply tank 23 is
connected through pipe 24 to the intake of the water pump 21; and,
pipeline 25 is attached to the exhaust of the water pump 21 and is
connected to flexible hose 16 by coupling 25a. An air compressor 26
is connected by pipeline 27 to an air receiver 28. The air receiver
28 is connected by a pipe 29 to an abrasive hopper 30 containing
the abrasive to be utilized herein. A pipe 31 is connected to the
pipe 29 and also to outlet 30a of the abrasive hopper 30 through
outlet pipe 31a. The pipe 31 is attached to flexible hose 15 by
coupling 31b. An instrument air line 32 is attached to the air
receiver 28 and extends to a pressure responsive valve 33 mounted
in the pipe 31. The instrument air line 32 is also connected to a
pressure responsive valve 34 which is mounted in the outlet pipe
30a. As schematically represented in FIG. 1, both the air
compressor 26 and the water pump 21 are driven by engine 22. The
term "pipe" as used herein includes any tube or line capable of
carrying air-abrasive or water.
A pipe 35 is attached to the air compressor output pipe 27 and
extends to and is connected with a corrosion inhibitor tank 36. An
outlet pipe 24a is attached to the corrosion-inhibitor tank and
extends into connection with the inlet of the water pump intake 21.
In the embodiment of the invention shown, the corrosion-inhibitor
line 24a is attached to the water supply line 24 by any suitable
coupling at 24b. An air pressure regulator valve 37 is mounted in
pipe 35 and cooperates with an air pressure cap 37a attached to the
corrosion-inhibitor tank 36 to control the pressure in the
corrosion-inhibitor tank 36. A metering valve 38 is mounted in the
corrosion-inhibitor outlet pipe 24a in order to provide an
adjustment for the amount of corrosion-inhibitor that is metered or
injected into the intake of the water pump 21.
The electric control means 14 is mounted onto the blasting gun 11
and extends into electrical connection with various elements in the
power station 20 through supply line 40. Referring to the
electrical schematic portion of FIG. 1 for the electric control
circuit 14, a battery 41 is connected by conductor line 41a to both
the trigger-mounted switches 14a and 14b. The switch 14a is mounted
in conductor line 42 which extends into connection with a
solenoid-operated inhibitor valve 43 mounted in pipe 24a. The
solenoid-operated valve 43 is movable between an open position
designated as 43a and a closed position designated as 43b. The
switch 14b is mounted in conductor line 44 which terminates in
electrical connection with conductor line 45. The conductor line 45
is electrically connected to a solenoid-operated valve 45 that is
movable between an open position designated as 46a and a closed
position designated as 46b. The conductor line 45 is electrically
connected to a throttle solenoid 47, which through throttle linkage
22a controls the speed of the engine 22. The solenoid 47 is of
conventional construction and includes stem 47a that is pivotally
connected to throttle linkage 22a. The closing of switch 14b causes
actuator solenoid 47 to move stem 47a and linkage 22a to the
position illustrated in FIG. 1, which is a high speed operation
position. The opening of switch 14b causes the solenoid 47 to move
the throttle linkage 22a to an open or idle position.
The water pump 21 is a high pressure water pump that pumps water
through pipe 25 and flexible hose 16 to the water conduit 11c and
outwardly through the nozzle 12 at a high pressure and a high
velocity as measured outside of the nozzle. The air compressor 26,
however, provides a relatively low pressure to the air receiver 28,
abrasive hopper 30 and pipe 31 for the purpose of delivering an
air-abrasive mixture to the blasting gun conduit 11d and nozzle 12.
With the valves 33 and 34 opened by air pressure through instrument
air line 32, air pressure is delivered into the top 30b of the
abrasive tank 30 and also into the pipe 31 past outlet line 31a of
the abrasive tank. The providing of a feed pressure at the top 30b
of the abrasive tank and the providing of air flow through line 31
causes the air in line 31 to mix with abrasive from out of line 31a
to provide an air-abrasive mixture which is pumped by the
compressor 26 through the flexible hose 15 to the blasting gun
conduit 11 and outwardly of the nozzle 12. The water pump 21 pumps
water at pressures above 3,000 p.s.i. in one embodiment of this
invention while the air compressor 20 pumps air in the low pressure
range of 20 to 100 p.s.i.
The nozzle 12 for the blasting gun 11 is provided for directing the
air-abrasive mixture separately from the high pressure water while
providing a resultant blasting stream 10 of air-abrasive and water
for impact cleaning without polluting the atmosphere. The nozzle 12
includes a body 12a having a central opening 12aa therein. The
central opening 12aa includes a threaded portion 12b which is
adapted to receive coupler 11f for the air-abrasive conduit 11d. A
center nozzle 50 includes tungsten inserts 50a that are mounted in
recesses 12c in the opening 12aa for projecting outwardly the
air-abrasive mixture at a low pressure. The axis of the center
nozzle 50 is illustrated by line 50b. A threaded hole 12d is
machined in the nozzle body 12a below the center nozzle 50 and the
water conduit 11c is threadly mounted therein. The nozzle body 12a
includes a horizontal passage 12f which extends through the hole
12d and vertical passages 12g and 12h which extend upwardly to a
top horizontal passage 12i. An intermediate horizontal passage 12j
is positioned between the lower horizontal passage 12f and top
horizontal passage 12i in fluid communication with the vertical
passages. The horizontal passages 12f, 12j, and 12i are in fluid
communication with the vertical passages 12g and 12h to provide a
network of passages in fluid communication with hole 12d so that
water may be distributed through the nozzle body 12a.
A set of short range water nozzles 52 are positioned at 90.degree.
intervals about the periphery of the center nozzle 50. Referring to
FIG. 2, each of the short range water nozzles includes a threaded
nozzle portion 52a which threadedly mounts the nozzle in a drilled
opening 12k in the nozzle body 12. The drilled opening 12k and the
water nozzle 52 have a common axis which is represented by line 53.
The axes 53 of the short range water nozzles converge to intersect
the axis 50b of the center nozzle 50 at a common point 10a. The
angle of intersection designated as 54 between the axes 53 of the
short range water nozzles 52 and the axis of the center nozzle 50
is preferably 21/2.degree.. The included angle 55 formed by the
intersection of the axes 53 of the short range water nozzles is
preferably 5.degree.. Each of the drilled openings 12k are in fluid
communication with the nozzle body water passages 12f, 12g, 12h,
12i, and 12j such that high pressure water can be directed through
such passages and outwardly of the water nozzle body 12a.
The short range water nozzle 52 thus directs streams of water at
high pressures outwardly along axes 53 in a conical pattern into
convergence at 10a with the stream of air-abrasive directed
outwardly of the center nozzle 50. The water streams from nozzles
52 converge with the air-abrasive stream a distance d from the
nozzle 12. The pressure and velocity of the air-abrasive mixture
directed outwardly of the center nozzle 50 is quite low as compared
to the pressure and velocity of the water directed outwardly of the
peripherally located water nozzles 52. The significantly higher
pressure, velocity and momentum of water directed outwardly along
the axis 53 mixes the air-abrasive mixture with the water and such
that the air-abrasive mixture is propelled with the water at the
substantially higher velocity and pressure of the water. In this
manner, an air-abrasive mixture and water are mixed to form a
blasting stream 10 of high pressure and velocity for cleaning
objects. One of the advantages of the nozzle 12 that directs an
air-abrasive mixture outwardly separately from the water is that
the center nozzle 50 is subjected to much less abrasive wear. At
the same time, the resultant blasting stream 10 travels at a very
high velocity and pressure in order to provide highly efficient
impact cleaning while minimizing dissemination of the abrasive as a
dust into the atmosphere.
Referring to FIGS. 3 and 4, a set of long-range nozzles 56 are
mounted in drilled openings 12l in nozzle body 12a peripherally of
the center nozzle 50. The long-range water nozzles 56 are
positioned between the short-range water nozzles 52 such that the
long-range water nozzles 56 are positioned at 90.degree. about the
center nozzle 50. The drilled openings 12l extend into fluid
communication with the nozzle body passages such as 12g and 12h in
a manner similar to the drilled openings 12k for the short-range
water nozzles 52. The axis 56a of each of long-range water nozzles
56 converges into intersection with the axis 50b of the center
nozzle 50 at a distance dd from the nozzle body 12a. The angle 57
between the axis 56a of the water nozzle 56 and the axis 50b of the
center nozzle 50 is preferably 1.degree.. Thus the angle 58 between
axes of the water nozzles 56 is preferably 2.degree.. The point of
convergence 10b of the axes 56a of the long-range water nozzles 56
is at a distance dd, which is greater than the distance d for the
short-range water nozzles 52. In utilizing the blasting nozzle 12,
either the long-range water nozzles 56 or the short-range water
nozzles 52 are used while the other set is plugged off by any
suitable means such as plugs which are the same as the nozzles
except that they are solid and have no nozzle opening. Thus, the
blasting nozzle 12 is capable of providing a short-range blasting
stream that is effective to a minimal distance d or a long-range
blasting stream effective to a minimal distance dd.
Various types of abrasives can be used in the high-pressure,
water-abrasive cleaning apparatus H of the preferred embodiment of
this invention. For example, sand, manufactured grit, slag, glass
beads or shot can be utilized simply by loading any of these
abrasives in the abrasive hopper 30. One of the advantages of this
invention is that of a smaller supply of abrasive as compared to
more conventional blasters for cleaning comparable objects.
Thereafter, the nozzle 12 of the blasting gun 11 is adjusted for
either short-range operation to a distance of at least d or
long-range operation to a distance of dd. As previously described,
the short-range water nozzles 52 are utilized alone simply by
substituting plugs for the long-range nozzles 56. Conversely, the
long-range nozzles 56 can be utilized alone simply by substituting
plugs for the short-range nozzles 52. After the nozzle range has
been chosen and the nozzle adjustments have been made for the
particular job, the apparatus H is ready to be used. Prior to use,
the operator first moves the blasting gun 11 to the desired
position. The blasting gun 11 is easily moved due to the flexible
hoses 15 and 16 which are used to connect the blasting gun 11 with
the pumping station 20, which can be located at a point remote from
the blasting gun 11.
After the operator is properly positioned with the blasting gun 11,
the blasting gun is placed against the body so that the shoulder
brace 11b is placed against the operator's shoulder and the
operator has one hand on the handle 11a. The operator then closes
the switch 14b. The closing of the switch 14b provides electrical
power from the battery 41 to the throttle solenoid 47, the solenoid
stem moving the linkage 22a to the operating position shown thereby
increasing power to both the water pump 21 and the air compressor
26. The air valve solenoid 46 is moved to the open position 46a at
the same time that the throttle solenoid 47 is activated. After the
compressor 26 and pump 21 are driven to operating pressures by
engine 22, air passes through line 32 to open the
pressure-responsive valves 33 and 34.
After the high pressure water pump 21 has attained operating
pressure, water is pumped under high pressure from the water supply
line 24, through line 25, flexible hose 16, water conduit 11c and
through the nozzle 12. The water is pumped through the nozzle valve
passages such as 12g and 12h and outwardly through either the
long-range water nozzles 56 or the short-range water nozzles 52. In
either event, the water is pumped outwardly in a generally conical
pattern at a very high pressure and converges into the stream of
air-abrasive. After the air compressor 26 has arrived at operating
pressure, air is provided under pressure through the air receiver
28 to lines 29 and 31. Air is provided through line 29 into the top
30b of the abrasive hopper 30 in order to provide a feed pressure
onto the abrasive within the hopper 30. Since the valves 33 and 34
are open, air pressure is provided through the line 31 past the
outlet line 31a of the hopper such that abrasive is carried with
the air through the flexible hose 15, air-abrasive conduit 11d and
into the nozzle 12. The air-abrasive mixture passes through the
abrasive conduit 11d and outwardly through the center nozzle 50
along the axis 50b into intersection with the water directed
outwardly from the water nozzles such as 52. The pressure of the
air-abrasive mixture is quite low, it need only be sufficient to
move the abrasive at a constant pressure and flow rate and direct
the air-abrasive mixture outwardly through the nozzle 50. However,
as previously mentioned, the pressure of the water being directed
outwardly through the water nozzles such as 52 is extremely high,
such as between about 3,000 p.s.i. to about 10,000 p.s.i. The
intersecting of the streams of water from the peripherally located
water nozzles such as 52 with the air-abrasive mixture directed
outwardly of the center nozzle 50 causes a mixing of the water with
the air-abrasive mixture and the propelling of the air-abrasive
mixture with the water towards the object being cleaned at very
high pressure and velocity. By utilizing the nozzle 12 of this
invention, the air-abrasive mixture is passed outwardly of the
nozzle prior to it being mixed with the water from the high
pressure nozzles such as 52. Thus, the internal components such as
the center nozzle 50 of the blasting nozzle 12 are not subjected to
the abrasive at a high pressure. This causes the center nozzle
portions to last for a substantially longer time than if the
abrasive were pumped outwardly of the nozzle at a higher pressure.
Further, the resultant stream 10 is a mixture of air-abrasive and
water such that the abrasive is not disseminated into the
atmosphere after impact with the object being cleaned. Further, the
propelling of the air-abrasive mixture by the water from the
peripherally located nozzles such as 52 provides a resultant
blasting stream 10 having a very high velocity and pressure for
very effective cleaning. For example, the velocity of the
air-abrasive mixture and the water in the resultant stream may be
approximately 800 feet per second to 1,250 feet per second or more,
which is an extremely effective velocity for such impact
cleaning.
When the operator desires to stop blasting, the operator opens the
switch 14b (which may be a spring loaded switch which automatically
moves to the open position upon release) thereby causing throttle
solenoid stem 47a to move linkage 22a to the idling position shown
in broken lines. Reduction of the engine speed to an idle reduces
the water flow from water pump 21 to the nozzle 12 to a minimum
which is usually a trickle. Simultaneously, with the reducing of
water flow to a minimum, solenoid operated valve 46 is moved to the
closed position 46b by the opening of switch 14b. The closing of
solenoid operated valve 46 shuts off air pressure to valves 33 and
34 thereby closing the valves and shutting off the flow of air in
line 29 and abrasive in line 31a, which shuts off the flow of
air-abrasive mixture to the nozzle 12. In this manner, the electric
control means 14 operates simultaneously to shut off all flow of
gas-abrasive mixture to the nozzle 12 and to reduce water flow to a
minimum.
It is occasionally desirable to provide a coating of
corrosion-inhibitor to the object which has been blasted clean. The
apparatus H of this invention can provide such corrosioninhibitor
in the following manner. After the engine 22 has been returned to
idling speed, the switch 14a is opened by the operator thereby
opening solenoid valve 43 and moving such valve to the open
position. With the valve 43 in the open position designated at 43a,
corrosion-inhibitor is forced outwardly through the line 24a due to
the constant, residual pressure in the inhibitor tank 36, which is
maintained by pressure cap 37a and the pressure regulator 37. The
corrosion-inhibitor passes through the metering valve 38 and into
the intake for the pump 21 and thus is pumped outwardly with water
through the peripherally located water nozzles such as 52 in the
blasting nozzle 12. The metering valve 38 may be utilized to adjust
the amount of corrosion-inhibitor which is injected into the pump
21. Generally, the corrosion-inhibitor is used only with the engine
22 at an idling speed and water flow through pump 21 is minimal in
order to conserve volume. However, it is noted that the
corrosion-inhibitor can also be used with the switch 14b open and
the engine 22, the pump 21 and the air compressor 26 at full
operating pressure.
The apparatus H of this invention has been disclosed in the
preferred embodiment as including a particular air compressor 26,
air receiver 28 and hopper 30, with the associated controls for
operation at the gun 11; it is also within the scope of this
invention to use a conventional abrasive supply with the remainder
of the apparatus H.
The foregoing disclosure and description of the invention are
illustrative and explanatory thereof, and various changes in the
size, shape and materials, as well as in the details of the
illustrated construction may be made without departing from the
spirit of the invention.
For example, the apparatus H of this invention has been described
as being utilized with water and air. It should be understood that
other liquid besides water can be used, and further, that a gas
other than air can be utilized, if suitable for such service.
Further, the nozzle sets 52 and 56 have been described very
precisely in terms of their angular relationship with respect to
the nozzle 50. Notwithstanding, it is within the scope of this
invention to provide nozzle sets at various angular positions such
that the distance of effectiveness of the nozzle is adjustable over
a wide range.
* * * * *