U.S. patent application number 13/065279 was filed with the patent office on 2011-09-29 for apparatus for aerohydrodynamic abrasive cleaning of surfaces, sprayer for the same, and method for aerohydrodynamic abrasive cleaning of surfaces.
Invention is credited to Alexandr Viktorovich Kostevich.
Application Number | 20110237162 13/065279 |
Document ID | / |
Family ID | 44657009 |
Filed Date | 2011-09-29 |
United States Patent
Application |
20110237162 |
Kind Code |
A1 |
Kostevich; Alexandr
Viktorovich |
September 29, 2011 |
Apparatus for aerohydrodynamic abrasive cleaning of surfaces,
sprayer for the same, and method for aerohydrodynamic abrasive
cleaning of surfaces
Abstract
An apparatus for mechanical spray treatment of materials has a
container for preparing an abrasive suspension, the container
having a stirring mechanism including a stirrer provided with at
least one blade, and a sprayer for spraying the abrasive suspension
connected to the container and a compressed gas supply device. The
stirrer of the stirring mechanism has a comminuting cutter provided
thereon in the bottom part of the container. The method for
aerohydrodynamic abrasive cleaning of surfaces includes entraining
the abrasive suspension flow in compressed gas to produce aerosol
particles and directing the stream of aerosol particles from the
sprayer nozzle to a surface. Moreover, after aerosol particles have
been formed they are accelerated owing to the sprayer design within
the sprayer before they are ejected from the nozzle. The method and
device help improve the output, efficiency, and quality of cleaning
by improving the uniformity of abrasive material grains used and
imparting a high velocity to the suspension spray, expanding the
area of effective cleaning, and distributing the aerosol particles
therein in an optimal proportion.
Inventors: |
Kostevich; Alexandr
Viktorovich; (g. Saint-Petersburg, RU) |
Family ID: |
44657009 |
Appl. No.: |
13/065279 |
Filed: |
March 18, 2011 |
Current U.S.
Class: |
451/38 ;
451/75 |
Current CPC
Class: |
B24C 7/0038
20130101 |
Class at
Publication: |
451/38 ;
451/75 |
International
Class: |
B24C 1/00 20060101
B24C001/00; B24C 3/00 20060101 B24C003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 2010 |
RU |
2010110986 |
Claims
1. An apparatus for aerohydrodynamic abrasive cleaning of surfaces
comprising a container for preparing an abrasive suspension by a
stirring mechanism including a stirrer having at least one blade,
and a sprayer for spraying the abrasive suspension connected to
said container and a compressed gas supply device, wherein the
stirrer of the stirring mechanism has a comminuting cutter provided
thereon in the bottom part of the container.
2. The apparatus as claimed in claim 1, wherein the stirring
mechanism comprises an air motor associated with the stirrer and
connected to the compressed air supply device through an air
preparation unit including a drier and a lubricant supply
device.
3. The apparatus as claimed in claim 1, wherein the mixing
container is provided with a filling funnel having a locking
device.
4. The apparatus as claimed in claim 1, further having a washing
liquid container connected to the sprayer through an air pump that
is connected to the compressed gas supply device through an air
preparation unit having a drier and a lubricant supply device.
5. The apparatus as claimed in claim 1, wherein the units thereof
are interconnected by hoses having valves provided thereon, the
hoses connected to the sprayer being provided with pressure
gauges.
6. A sprayer for aerohydrodynamic abrasive cleaning of surfaces
comprising a hollow body provided with a nozzle at the outlet
thereof, a compressed gas flow channel and a cleaning suspension
flow channel, both connected to the body interior, wherein the
compressed air flow channel is connected to the cylindrical
interior of the body at the side thereof opposite to the nozzle,
the sprayer is provided with an atomizer in the form of a T pipe
received in the body interior, the crosspiece of said T pipe
extending along the body axis and the vertical leg thereof being
connected to the cleaning suspension flow channel, the nozzle has a
tapering part and a cylindrical part at the outlet thereof, and the
outlet aperture of the atomizer is spaced from the inlet of the
cylindrical part of the nozzle to provide a zone for accelerating
cleaning suspension aerosol particles.
7. A method for aerohydrodynamic abrasive cleaning of surfaces by
entraining the abrasive suspension flow in compressed gas to
produce aerosol particles and directing the stream of aerosol
particles from the sprayer nozzle at the surface, wherein the
aerosol particles formed are accelerated within the sprayer before
they are ejected from the nozzle.
8. The method as claimed in claim 7, wherein the nozzle has a part
that does not flare at the outlet thereof.
9. The method as claimed in claim 7, wherein the abrasive
suspension comprises solid particles of loam and silica and water,
wherein the loam and silica are used in the following proportions,
in mass %: loam 25 to 90 silica 10 to 75.
10. The method as claimed in claim 9, wherein the solid loam and
silica particles have a size of 100 .mu.m to 1.8 mm.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] Applicant claims priority under 35 U.S.C. .sctn.119 of
Russian Application No. 2010110986 filed Mar. 23, 2010, the
disclosure of which is incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The group of inventions relates to mechanical spray
treatment of materials and can be used in various fields for
cleaning any surfaces from organic and inorganic dirt, removing
coatings, including coating removal layer by layer; for imparting
new adhesive properties to the surface cleaned; combining surface
cleaning and passivating; and cleaning many types of items meeting
specific requirements to fatigue strength and uncontrollable
chemical processes in operation.
[0003] The invention can be used in the heavy and metal industries,
for example, on the shop floor of metal making plants for removing
scale from the surface of semi-manufactured products made of
ferrous and nonferrous metals; in blank production shops of
mechanical engineering plants for removing oxide films, rust, and
so on; cleaning prior to painting; preparing surfaces for welding,
brazing, and application of corrosion-resistant and other
protective coats; dimensionless grinding preceding final polishing
of components; cleaning filled floors; and so on. In power
engineering, the oil and gas industries, and aviation, the
invention can be used, for example, for cleaning and treating the
blades of turbine rotors at cogeneration plants, hydroelectric
power plants, nuclear power plants (repairs of gas turbine and
steam engines, turbines, and so on), and aircraft engines; cleaning
and treating the blades of turbine rotors of oil and gas piping
equipment; cleaning pipeline elements and threads; deactivating
radioactive contamination, and so on. In transportation and at
shipyards, the invention can be used for cleaning railroad cars
from dirt, including graffiti, cleaning railroad cars, wheel sets
of railroad cars prior to flaw detection procedures; cleaning
vehicle bodies and preparing components prior to painting; and
cleaning ship hulls, components, and equipment. In housing and
utilities, construction, and restoration projects, the invention
can be used for cleaning various house front surfaces from
atmospheric pollutants, dirt and soil, artificial pollution, and
biological destructive agents.
[0004] The closest prior art of the claimed apparatus for
aerohydrodynamic (AHD) abrasive cleaning of surface, its sprayers,
and cleaning method are, respectively, the apparatus, sprayer, and
cleaning method disclosed in U.S. Pat. No. 1,740,142 A1 published
on Jun. 15, 1992 [1].
[0005] The prior art apparatus for aerohydrodynamic abrasive
cleaning of surfaces comprises a container for preparing an
abrasive suspension, including a stirring mechanism provided with a
bladed stirrer, and a sprayer provided with a flaring nozzle to
spray the abrasive suspension and connected to the container and a
compressed air device.
[0006] The prior art apparatus is disadvantageous because of the
low quality of cleaning by mixtures containing relatively coarse
and/or nonuniform grains.
[0007] The prior art sprayer for aerohydrodynamic abrasive cleaning
of surfaces comprises a hollow body provided with a flaring nozzle
at the outlet, and a compressed air flow channel and a cleaning
suspension flow channel, both connected to the body interior.
[0008] The prior art sprayer is disadvantageous because of its low
cleaning efficiency due to improper matching of the suspension
spray velocity, concentration of abrasive particles in the
suspension, and the shape and effective area of the cleaning
flare.
[0009] The prior art method for aerohydrodynamic abrasive cleaning
of surfaces comprises injecting compressed gas into the abrasive
suspension flow to produce aerosol particles and directing the
stream of aerosol particles from the sprayer nozzle at the surface
being cleaned.
[0010] The prior art method is disadvantageous because of its low
cleaning efficiency due to improper matching of the suspension
spray velocity, concentration of abrasive particles in the
suspension, and the shape and effective area of the cleaning
flare.
SUMMARY OF THE INVENTION
[0011] The technical result of the claimed group of inventions
consists in increasing output, efficiency, and quality of cleaning
by improving the uniformity of abrasive material grains and
imparting a high velocity to the suspension spray, enlarging the
effective cleaning area, and achieving optimal distribution of
abrasive particles and water therein.
[0012] The technical result is achieved in an apparatus for
aerohydrodynamic abrasive cleaning of surfaces, said apparatus
comprising a container for preparing abrasive suspension that has a
stirring mechanism including a stirrer having at least one blade,
and a sprayer for spraying the abrasive suspension that is
connected to said container and to a compressed gas supply device,
said stirrer of the stirring mechanism comprising a comminuting
cutter provided thereon in the bottom part of the container.
[0013] In the specific embodiments of the invention, the stirring
mechanism may comprise an air motor connected to the stirrer and to
the compressed gas supply device through an air preparation unit
that includes a drier and a lubricant supply device.
[0014] The suspension preparation container may be provided with a
filling funnel having a locking device.
[0015] The apparatus may be provided with a washing liquid
container connected to the sprayer through an air pump that is
connected to the compressed air supply device through the air
preparation unit including a drier and a lubricant supply
device.
[0016] The apparatus units may be interconnected by hoses provided
with valves, the hoses connected to the sprayer having pressure
gauges.
[0017] The grain non-uniformity problem has been resolved by
providing the apparatus with a comminuting cutter, a structural
element that makes the mass uniform and suitable for producing an
AHD mixture and helps grind larger grains to a particle size of 100
.mu.m to 300 .mu.m that are more effective in cleaning a larger
area in square meters per hour.
[0018] The object of this invention is also achieved by the
specific design of a sprayer for aerohydrodynamic cleaning of
surfaces that contains a hollow body provided with a nozzle at the
outlet thereof, a compressed air flow channel and a cleaning
suspension flow channel, both connected to the body interior, the
compressed air flow channel being connected to the cylindrical
interior of the body at the side opposite to the nozzle, the
sprayer being provided with an atomizer in the shape of T pipe
placed within the body interior, the crosspiece of the T pipe
extending along the body axis and the vertical leg thereof being
connected to the cleaning suspension flow channel; the nozzle
having a tapering part and a cylindrical part at the outlet
thereof, and the outlet aperture of the atomizer being positioned
at a distance from the inlet of the cylindrical part of the nozzle
to provide a zone for accelerating the aerosol particles of the
cleaning suspension.
[0019] The object of the invention is also achieved in a method for
aerohydrodynamic abrasive cleaning of surfaces comprising injecting
compressed air into the abrasive suspension flow to produce aerosol
particles and directing the stream of aerosol particles from the
sprayer nozzle at the surface, the aerosol particles produced as
above being accelerated within the sprayer before they are ejected
from the nozzle.
[0020] It is preferred to use a nozzle having a part that does not
flare at the outlet thereof.
[0021] Furthermore, the abrasive suspension used for the purposes
of this invention contains solid particles of loam and silica in
water in the following proportions of solids, in mass %:
[0022] loam 25 to 90
[0023] silica 10 to 75
[0024] It is preferred for loam and silica solids to have a size
ranging from 100 .mu.m to 1.8 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The idea of the invention is described below with reference
to the drawings wherein;
[0026] FIG. 1 is a diagrammatic view of the claimed apparatus;
[0027] FIG. 2 is a view of a first embodiment of a through sprayer
using a T pipe; and
[0028] FIG. 3 is a diagram showing connections between the units of
the claimed apparatus.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] The apparatus for aerohydrodynamic abrasive cleaning of
surfaces (see: FIG. 1 and FIG. 3) comprises a container 1 for
preparing abrasive suspension that includes a stirring mechanism
and a sprayer 2 for spraying the abrasive suspension connected to
container 1 and a compressed gas supply device 3.
[0030] The stirring mechanism comprises a stirrer 4 and an air
motor 5 associated therewith and connected to a compressed gas
supply device 3 through an air preparation unit 6 that includes a
drier 7 and a lubricant supply device 8. Stirrer 4 is provided with
blades 9 and a comminuting cutter 10 provided thereon in the bottom
part of container 1.
[0031] Stirring container 1 is provided with a filling funnel 11
having a locking device 12.
[0032] The apparatus has a washing liquid container 13 connected to
sprayer 2 through an air pump 14 connected to compressed air supply
device 3 through air preparation unit 6.
[0033] The apparatus units are interconnected by hoses provided
with valves 15, with pressure gauges 29 provided on the hoses
connected to sprayer 2. The hose connecting air preparation unit 6
to container 1 is provided with a pressure gauge 30.
[0034] The top part of container 1 is provided with a filling
aperture 31 and a 6 atm. safety valve 32.
[0035] Sprayer 2 (see: FIG. 2) comprises a hollow body and a nozzle
17 at the outlet thereof. The interior of container 1 is connected
to a compressed air flow channel and a cleaning suspension flow
channel 19. Compressed air flow channel 18 is connected to the
cylindrical interior of body 1 at the side thereof opposite to
nozzle 17. The interior of body 1 houses an atomizer in the form of
a T pipe 20, the crosspiece 21 thereof extending along the body
axis, and the vertical leg 21 thereof being connected to cleaning
suspension flow channel 19'. Nozzle 17 has a tapering part 23 and a
cylindrical part 24 at the outlet thereof, the outlet opening 25 of
the atomizer being spaced at a distance from the inlet of
cylindrical part 24 of nozzle 17 to provide an acceleration zone
for the aerosol particles of the cleaning suspension.
[0036] Sprayer 2 has a clearly defined zone (Zone A) for
accelerating the incoming air. It also has a Zone B for
accelerating the mixture of air and cleaning suspension for mixing
air with the suspension and initially accelerating the resultant
mixture, and a Zone C in nozzle 24 of the accelerator for
accelerating the mixture still further to produce a working flare
of a large area and high cleaning efficiency.
[0037] Examples of loam and quartz dust mixtures used for cleaning
purposes:
[0038] PP-MT 30: 30% of loam and 70% of powdered quartz;
[0039] PP-MT 50: 50% of loam and 50% of powdered quartz;
[0040] PP-MT 70: 70% of loam and 30% of powdered quartz; and
[0041] PP-MT 90: 90% of loam and 10% of powdered quartz.
[0042] The cleaning mixtures are dispersions of washed loam and
special-purpose additives.
[0043] The above-mentioned mixtures may comprise GOST-28177-89
Standard loam of grain size down to 40 .mu.m and GOST-9077-82
Standard powdered quartz of grain size down to 40 .mu.m.
[0044] It is more preferred, though, to use grains ranging from 100
.mu.m to 1.8 mm in size. Coarser grains are used for removing heavy
pollution such as corrosion and aged paint and allow surfaces to be
cleaned to quality Sa2 under ISO 8501-1 Standards, and finer grains
(between 100 .mu.m and 300 .mu.m) are further comminuted as they
are mixed and are suitable for AHD cleaning and treating surfaces
without modifying the chemical composition of the surface layer
thereof, which is a critical factor for many types of items
required to have a high fatigue strength and resistance to
uncontrolled chemical processes in operation, and achieve cleaning
quality of Sa3 under ISO 8501-1 Standards.
[0045] The choice of a cleaning mixture depends on the extent and
type of pollution of the surface to be cleaned, equipment,
finishing materials, conditions of house front walls, and presence
of architectural features, and is dictated by the technique adopted
for a specific job.
[0046] A majority of pollutions are cleaned by a mixture of no more
than 6 liters of cleaning mixture and 40 liters of water. Tap water
is used for ultimately washing the cleaning products off the front
wall of a house.
[0047] The PP-MT 30 mixture is used for cleaning heavy pollution,
removing paint from a surface, removing rust and scale, for
example, cleaning metal structures made from aluminum alloys and
other nonferrous metals from atmospheric and other pollution.
[0048] The PP-MT 50 mixture is used for cleaning moderate
pollutions, removing paint layer by layer, removing rust, moss,
mildew, soot, graffiti from house front walls, and cleaning turbine
rotors and architectural monuments.
[0049] The PP-MT 70 mixture is used for removing light pollutions,
traces of salt, and dirt, soil, and atmospheric pollutions.
[0050] The PP-MT 90 mixture is used for cleaning fragile surfaces
from light pollutions.
[0051] To prevent development of centers of biological destructive
agents on front walls and monuments, powdered lime that conforms to
the GOST-9179-77 Standards having a grain size of up to 100 .mu.m
may be used as a cleaning mixture.
[0052] The claimed method is performed during the operation of the
apparatus as follows:
[0053] The apparatus can operate in the cleaning,
washing/waterproofing, and drying modes. The operating modes of the
sprayer are selected by opening or closing the respective valves
provided on sprayer 2 and having pipes connected thereto.
[0054] The apparatus has to be operated at an ambient air
temperature of or above +5.degree. C.
[0055] Depending on the type and extent of pollution, the spacing
between the surface being cleaned and the outlet aperture of nozzle
24 is preferably between 50 and 180 mm. In operation, the nozzle
axis has to be directed at an angle of 60 to 80 degrees to the
house front wall being cleaned.
[0056] Operation of the apparatus comprises the successive steps
of: [0057] checking the air and suspension supply systems for gaps;
[0058] connecting the air supply hoses to the compressor and
checking the connection for reliability and twists of the air and
suspension supply hoses; [0059] filling container 1 with a ready
mixture or preparing the mixture in container 1 itself by pouring
tap water into the container and adding the solid component of
required concentration; [0060] turning on the mixture stirring
mechanism for preliminary stirring of the mixture for at least 10
seconds; and [0061] turning on air and suspension flow into their
respective lines and holding sprayer 2 firmly in hand and directing
nozzle 24 toward the surface being cleaned.
[0062] In the cleaning mode, air flows under a pressure of 4 to 12
atm. into air supply device 3 where it is distributed to the
respective systems. Air is dried in drier 7 of air preparation unit
6 and lubricant is added thereto from lubricant supply device
8.
[0063] Air flows from unit 6, through a valve/controller, to air
motor 5 that transmits rotation to stirrer 4 provided with blades 9
and comminuting cutter 10 to stir the mixture of water and cleaning
material or comminute dry cleaning material of soda type in
container 1.
[0064] Air also flows from unit 6 to container 1 for preparing
abrasive suspension and maintaining pressure therein at 1 to 1.5
atm. required for preparing a suspension and pumping it through a
hose to sprayer 2.
[0065] When the cleaning material is mixed with water in the PP-MT
proportions given above an abrasive suspension is produced at a
pressure of 1 to 1.5 atm. it requires for displaying its AHD
properties and producing the Rebinder effect.
[0066] The suspension is pumped from container 1 through channel 19
to pipe 20 or to an annular chamber 27 to be mixed at the outlet
thereof with the air stream flowing under high pressure in channel
18 from device 3 and is accelerated. From that point on, the
mixture of air and suspension is accelerated to high velocities.
The stream effect produces the so-called hydro-abrasive aerosol
consisting of abrasive particles, air, and liquid. The
hydro-abrasive aerosol thus produced is used to clean surfaces. The
high-velocity air stream (flowing at over 500 m/sec) is the energy
agent carrying aerosol particles in the AHD method. Aerosol
particles are water molecules gathered into drops under high
pressure (about 1 atm.), with solid particles (abrasive dust)
measuring between 300 nm and 40 .mu.m trapped inside them. As water
strikes a surface, it reduces, due to the Rebinder effect, the
strength of the surface being cleaned, whereupon an abrasive
particle destroys the dirt, and water flushes out the broken
fragments and washes them away together with the abrasive used.
[0067] The working fluid carries abrasive particles from the supply
container to the surface being treated, cleans the surface being
treated continuously, removes the spent abrasive particles and
particles of the material dislodged, prevents dusting, controls the
heat in the treatment zone, and allows cleaning wastes to be
collected and the working mixture to be used again.
[0068] In the washing/waterproofing mode, air pump 14, also
operated by air supplied from device 3, forces water or
waterproofing agent from washing liquid container 13 through a hose
to sprayer 2.
[0069] The drying mode is turned on by closing two valves 15 on the
hoses connected to containers 1 and 13 and opening valve 15 of the
hose connected to air supply device 3. The air stream ejected as a
result from sprayer 2 is used to dry a damp surface.
[0070] The claimed method used to treat a surface does not affect
negatively the original surface of metal, which is an advantage
that distinguishes it from other cleaning and deactivating methods.
Treatment by the claimed method does not alter the physical and
chemical composition of the surface layer of metal, which is a
valuable factor for many types of components required to be
resistant to fatigue strength deterioration and uncontrollable
chemical processes in operation. Moreover, the claimed method helps
improve the adhesive properties of metal because of reduced water
absorption by the surface thereof following treatment by the
claimed method.
* * * * *