U.S. patent application number 17/270592 was filed with the patent office on 2021-12-02 for multi-outlet pressure vessel, system, and method for wet abrasive blasting.
The applicant listed for this patent is Graco Minnesota Inc.. Invention is credited to Patrick W. Ackerman, Alexander J. Daeger, Bryce J. Gapinski, Niles M. Hickman, Nicholas K. Studt.
Application Number | 20210370468 17/270592 |
Document ID | / |
Family ID | 1000005752233 |
Filed Date | 2021-12-02 |
United States Patent
Application |
20210370468 |
Kind Code |
A1 |
Studt; Nicholas K. ; et
al. |
December 2, 2021 |
MULTI-OUTLET PRESSURE VESSEL, SYSTEM, AND METHOD FOR WET ABRASIVE
BLASTING
Abstract
A wet abrasive blasting system includes a vessel having multiple
outlets for dispensing slurry. A first sprayer of the system is
operatively associated with a first blast control switch, and a
second sprayer is operatively associated with an n-th blast control
switch. A first blast line fluidly connecting the first sprayer to
the first outlet includes a first pinch valve, and an n-th blast
line fluidly connecting the n-th sprayer to the n-th outlet
includes an n-th pinch valve. A time delay module of the system
transmits signals to close all system pinch valves upon receipt of
signals indicative of an actuated state of more than one blast
control switch and, after a predetermined time delay, transmits
signals to open all system pinch valves associated with their
respective actuated blast control switches.
Inventors: |
Studt; Nicholas K.;
(Roberts, WI) ; Gapinski; Bryce J.; (Minneapolis,
MN) ; Hickman; Niles M.; (Delano, MN) ;
Daeger; Alexander J.; (Roseville, MN) ; Ackerman;
Patrick W.; (Minneapolis, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Graco Minnesota Inc. |
Minneapolis |
MN |
US |
|
|
Family ID: |
1000005752233 |
Appl. No.: |
17/270592 |
Filed: |
September 10, 2019 |
PCT Filed: |
September 10, 2019 |
PCT NO: |
PCT/US19/50389 |
371 Date: |
February 23, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62729017 |
Sep 10, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24C 5/02 20130101 |
International
Class: |
B24C 5/02 20060101
B24C005/02 |
Claims
1. A wet abrasive blasting system comprising: a vessel comprising a
first outlet and a second outlet for providing a slurry; a first
sprayer operatively associated with a first blast control switch; a
second sprayer operatively associated with a second blast control
switch; a first pinch valve disposed along a first blast line
fluidly connecting the first sprayer to the first outlet; a second
pinch valve disposed along a second blast line fluidly connecting
the second sprayer to the second outlet; a logic module configured
to: receive a first blast signal indicative of an actuated state of
the first blast control switch; and receive a second blast signal
indicative of an actuated state of the second blast control switch;
and a time delay module wherein: upon receipt of the second blast
signal during the actuated state of the first blast control switch
by the logic module, the time delay module is configured to:
transmit a first closure signal to the first pinch valve to close
the first pinch valve; and transmit a second closure signal to the
second pinch valve to maintain the second pinch valve in a closed
position; and after a predetermined time delay starting upon
receipt of the second blast signal, the time delay module is
further configured to: transmit first and second opening signals to
first and second pinch valves, respectively, to open the first and
second pinch valves.
2. The wet abrasive blasting system of claim 1 and further
comprising: a pump comprising an intake port in fluid communication
with a fluid source and a discharge port; a first solenoid valve
positioned along a first delivery line fluidly connecting the pump
discharge port to an inlet of the vessel; and a second solenoid
valve positioned along a second delivery line fluidly connecting
the pump discharge port to the vessel inlet; wherein, upon
receiving the first blast signal, the logic module is configured to
transmit a third opening signal to the first solenoid valve to open
the first solenoid valve; and wherein, upon receiving the second
blast signal, the logic module is configured to transmit a fourth
opening signal to the second solenoid valve to open the second
solenoid valve.
3. The wet abrasive blasting system of claim 2, wherein the logic
module is further configured to: transmit a third closure signal to
the first pinch valve to close the first pinch valve upon receiving
a third blast signal indicative of an unactuated state of the first
blast control switch.
4. The wet abrasive blasting system of claim 3, wherein upon
receiving the third blast signal, the logic module is further
configured to: transmit a fourth closure signal to the first
solenoid valve to close the first solenoid valve.
5. The wet abrasive blasting system of claim 4, wherein upon
receiving a fourth blast signal indicative of an unactuated state
of the second blast control switch, the logic module is further
configured to: transmit a fifth closure signal to the second pinch
valve and transmit a sixth closure signal to the second solenoid
valve to close the second pinch valve and the second solenoid
valve.
6. The wet abrasive blasting system of claim 5, wherein the logic
module is configured to open a bypass valve positioned along a
bypass line fluidly connecting the pump discharge port to the
vessel inlet upon receiving blast signals indicative of unactuated
states of all blast control switches.
7. The wet abrasive blasting system of claim 1 and further
comprising: a compressed air source; first and second compressed
air lines fluidly connecting the compressed air source to the first
and second sprayers, respectively; wherein the first and second
compressed air lines fluidly connect with the first and second
blast lines, respectively, at the first and second sprayers,
respectively; wherein the actuated state of the first blast control
switch discharges compressed air from the first sprayer; and
wherein the actuated state of the second blast control switch
discharges compressed air from the second sprayer.
8. The wet abrasive blasting system of claim 1, wherein the vessel
includes a partial internal partition, the internal partition
defining a first volume that includes the first outlet and a second
volume that includes the second outlet, and wherein the vessel
includes a third volume fluidly connecting the first volume to the
second volume.
9. The wet abrasive blasting system of claim 2 and further
comprising: a first regulating valve along the first delivery line
having a first adjustable valve element operable to adjust a first
flow rate within the first delivery line; and a second regulating
valve along the second delivery line having a second adjustable
valve element operable to adjust a second flow rate with the second
delivery line.
10. The wet abrasive blasting system of claim 2, wherein the
predetermined time delay is greater than a time required for the
pump to increase a pressure within the vessel to a target operating
pressure sufficient to operate the first sprayer and the second
sprayer at a target flow rate.
11. A method controlling a wet abrasive system, the method
comprising: receiving a first blast signal indicative of an
actuated state of a first blast control switch at a logic module,
wherein the first blast control switch is operatively associated
with a first sprayer, the first sprayer fluidly connected to a
first outlet of a vessel by a first blast line; receiving a second
blast signal indicative of an actuated state of a second blast
control switch at the logic module, wherein the second blast
control switch is operatively associated with a second sprayer, the
second sprayer fluidly connected to a second outlet of the vessel
by a second blast line; transmitting, upon receipt of the second
blast control signal by the logic module during the actuated state
of the first blast control switch, a first closure signal from a
time delay module to a first pinch valve and a second closure
signal from the time delay module to a second pinch valve, wherein
the first and second closure signals close the first pinch valve
and the second pinch valve, respectively, and wherein the first
pinch valve is disposed along the first blast line, and the second
pinch valve is disposed along the second blast line; transmitting,
after a predetermined time delay starting upon receipt of the
second blast signal, a first opening signal from the time delay
module to the first pinch valve and a second opening signal from
the time delay module to the second pinch valve.
12. The method of claim 11 and further comprising: transmitting a
third opening signal from the logic module to a first solenoid
valve upon receipt of the first blast signal, wherein the third
opening signal opens the first solenoid valve, and wherein the
first solenoid is positioned along a first delivery line fluidly
connecting a pump discharge port to an inlet of the vessel.
13. The method of claim 12 and further comprising: transmitting a
third closure signal to the first pinch valve upon receiving a
third blast signal indicative of an unactuated state of the first
blast control switch by the logic module, wherein the third closure
signal closes the first pinch valve.
14. The method of claim 13 and further comprising: transmitting a
fourth closure signal from the logic module to the first solenoid
valve upon receipt of the third blast signal by the logic module,
wherein the fourth closure signal closes the first solenoid
valve.
15. The method of claim 15 and further comprising: transmitting a
fifth closure signal from the logic module to the second solenoid
valve and transmitting a sixth closure signal from the logic module
to the second pinch valve upon receiving a fourth blast signal
indicative of an unactuated state of the second blast control
switch, wherein the fifth closure signal closes the second solenoid
valve, and the sixth closure signal closes the second pinch
valve.
16. The method of claim 16 and further comprising: opening a bypass
valve using the logic module upon receipt of blast signals
indicative of unactuated states of all blast control switches,
wherein the bypass valve is positioned along a bypass line fluidly
connecting the pump discharge port to the vessel inlet.
17. The method of claim 11 and further comprising: supplying
compressed air from a compressed air source to the first sprayer
along a first compressed air line in response to the first blast
control switch in the actuated state; and supplying compressed air
from the compressed air source to the second sprayer along a second
compressed air line in response to the second blast control switch
in the actuated state; wherein the first and second compressed air
lines fluidly connect with the first and second blast lines,
respectively, at the first and second sprayers, respectively.
18. The method of claim 12 and further comprising: setting a first
flow rate through the first delivery line with a first adjustable
valve element of a first regulating valve disposed along the first
delivery line; and setting a second flow rate through the second
delivery line with a second adjustable valve element of a second
regulating valve disposed along the second delivery line.
19. The method of claim 12, wherein the predetermined time delay is
greater than a time required for the pump to increase a pressure
within the vessel to a target operating pressure sufficient to
operate the first sprayer and the second sprayer at a target flow
rate.
20. A wet abrasive blasting system comprising: a vessel comprising
a first outlet and a second outlet for providing a slurry and an
inlet; a first sprayer operatively associated with a first blast
control switch; a second sprayer operatively associated with a
second blast control switch; a first pinch valve disposed along a
first blast line fluidly connecting the first sprayer to the first
outlet; a second pinch valve disposed along a second blast line
fluidly connecting the second sprayer to the second outlet; and a
first compressed air line fluidly connecting the first sprayer to a
compressed air source; a second compressed air line fluidly
connecting the second sprayer to the compressed air source; a pump
comprising an intake port in fluid communication with a fluid
source and a discharge port; a first solenoid valve positioned
along a first delivery line fluidly connecting the pump discharge
port to the vessel inlet; a second solenoid valve positioned along
a second delivery line fluidly connecting the pump charge the
vessel inlet; a logic module comprising configured to: receive a
first blast control signal indicative of an actuated state of the
first blast control switch; transmit, upon receipt of the first
blast signal, a first opening signal to the first pinch valve and a
second opening signal to the first solenoid valve; and receive a
second blast control signal indicative of an actuated state of the
second blast control switch after receiving the first blast control
signal and during the actuated state of the first blast control
switch; and a time delay module that, upon receipt of the second
blast signal, is configured to: transmit a first closure signal to
close the first pinch valve and transmit a third opening signal to
open the second solenoid valve; and transmit fourth and fifth
opening signals to open first and second pinch valves,
respectively, after a predetermined time delay starting upon
receipt of the second blast signal.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/729,017 filed Sep. 10, 2018 for "MULTI-OUTLET
PRESSURE VESSEL FOR WET ABRASIVE BLASTING" by N. K. Studt, B. J.
Kapinski, N. M. Hickman, A. J. Daeger and P. W. Ackerman.
FIELD OF INVENTION
[0002] The invention is directed to abrasive blasting systems for
cleaning, preparing surfaces, removing coatings, and other abrasive
blasting operations. Embodiments of the wet abrasive blasting
system and methods provide consistent flow of air, water, and
abrasive for multiple outlets.
BACKGROUND
[0003] To remove the paint, dirt, or other surface coating from a
substrate such as a surface to be painted or cleaned, a blasting
system may be both desirable and necessary. There are a variety of
blasting processes for these purposes, including but not limited
to, water blasting, dry abrasive blasting, and wet abrasive
blasting. In certain applications, abrasive blasting systems are
able to efficiently clear or remove a coating without damaging the
underlying metal or other substrate. Although in other
applications, a certain degree of surface roughening may be
desired.
[0004] The use of dry abrasive blasting with particles such as
those used in conventional sand blasting may result in surface
roughness and other damage to the substrate. Typical blast
particles are hard and abrasive in order to increase the efficiency
of the blasting operation but therefore may result in damage to the
substrate. Soft recyclable blast particles are sometimes
substituted to avoid surface damage. These recyclable blast
particles include, but are not limited to, agricultural products
such as crushed walnut shells, crushed pistachio shells, and rice
hulls. Plastic particles are sometimes used to reduce substrate
surface damage but may also result in a reduction in efficiency of
the blasting operation.
[0005] Wet abrasive systems have been used to also control surface
damage. Wet abrasive systems combine the benefits of these blasting
systems and dry abrasive blasting systems. In wet abrasive
blasting, the fluid may encapsulate the abrasive media to
simultaneously add mass to the abrasive and buffer the impact of
the abrasive against the substrate to reduce potential surface
damage but still effectively strip or clean the surface while also
reducing the dust produced compared to a dry abrasive blasting
system. However, wet abrasive systems require efficient mixing of
slurry and a gas stream to produce a consistent stream of a
three-phase mixture of fluid, solid abrasive, and gas stream. If
the mixing of slurry and pressurized gas is not well controlled,
the blasting process is less efficient and the benefits of a wet
abrasive system are not fully realized. For many large blasting
projects, multiple operators are needed to efficiently complete the
project. As such, there is a need for an abrasive system that
allows for multiple operators using a single system.
SUMMARY
[0006] In one exemplary embodiment, a wet abrasive blasting system
includes a vessel having a first outlet and a second outlet for
dispensing slurry. The wet abrasive blasting system can further
include a first sprayer operatively associated with a first blast
control switch and a second sprayer operatively associated with a
second blast control switch. A first blast line fluidly connecting
the first sprayer to the first vessel outlet includes a first pinch
valve, and a second blast line fluidly connecting the second
sprayer to the second vessel outlet includes a second pinch valve.
A time delay module of the system transmits signals to close all
system pinch valves upon receipt of signals indicative of an
actuated state of more than one blast control switch. The time
delay module further transmits signals to open all system pinch
valves associated with their respective actuated blast control
switches after a predetermined time delay following the receipt of
signals indicative of an actuated state of more than one blast
control switch.
[0007] An exemplary method includes receiving first and second
blast signals indicative of actuated first and second blast control
switches, each blast control switch operatively associated with a
different sprayer fluidly connected to a different outlet of a
pressure vessel or blasting pot. The method further includes
transmitting signals from a time delay module to close both pinch
valves upon receipt of signals indicative of actuated first and
second blast control switches contemporaneously and transmitting
signals from the time delay module to open the first and second
pinch valves after a predetermined time delay following receipt of
signals indicative of actuated first and second blast control
switches.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an exemplary schematic of a single pump
configuration of a multiple outlet blast system.
[0009] FIG. 2 is an exemplary schematic of a multiple pump
configuration of a multiple outlet blast system.
[0010] FIG. 3A-3D are exemplary pressure vessel configurations with
multiple outlets of a multiple outlet blast system.
DETAILED DESCRIPTION
[0011] As described herein, examples of wet abrasive blasting
systems include at least one pressure vessel (or blast pot)
equipped with multiple outlets, each outlet supplying a different
sprayer for dispensing a wet abrasive blast media composed of a
mixture of compressed air, water, and abrasive media.
[0012] In one example, the wet abrasive blasting system includes a
logic module and a time delay module that are responsive to blast
control switches, each blast control switch associated with a
different sprayer connected to a different outlet of a vessel. The
blast control switches being associated with the sprayers relates
to the function of controlling a sprayer by the respective switch.
The logic module and the time delay module each include a network
of analog logic components or a digital logic module configured to
delay introduction of abrasive media into the blast lines, or delay
water delivery to the vessel (or blast pot). Delaying the
introduction of the abrasive media into the blast lines allows the
vessel pressure to equalize with fluid delivery lines upstream of
the vessel while delaying introduction of water into the vessel
permits the vessel pressure to equalize with blast lines downstream
from the vessel (or blast pot).
[0013] In other examples, the wet abrasive system includes a vessel
with outlets arranged according to spacing requirements, a baffle
positioned between at least two outlets, or a combination of outlet
spacing and baffle arrangements. Vessels of this type can be
configured to look like a standard vessel externally except for
having two or more outlets at the bottom of the vessel. Internally,
the baffles, outlet spacing, or a combination of both facilitate a
consistent media flow such that each outlet can be independently
controlled. In still other examples, two or more vessels can be
linked together via pathways for equalizing vessel pressure within
an internal volume of the assembly.
[0014] Any of these embodiments, as well as embodiments combining
features from two or more of the above embodiments, enable multiple
operators to perform wet abrasive blasting while limiting the
pressure differential between two adjacent vessel outlets or among
a group of vessel outlets. The beneficial pressure distributions
within the vessel (or blast pot) provide consistent flows of air,
water, and abrasive through a single blast line or, additionally,
through multiple blast lines during a blasting operation.
[0015] FIG. 1 is an exemplary schematic of a single pump blasting
system 10 that includes vessel 12 equipped with multiple inlets
14a, 14b, through 14n and multiple outlets 16a, 16b, through 16n.
Each blast line 18a, 18b, through 18n of system 10 fluidly connect
one of vessel outlets 16a-16n to one of sprayers 20a-20n. Pump 22
acts on fluid, for example water, received from a fluid source
through intake port 22a to deliver pressurized fluid through
discharge port 22b. Delivery lines 24a-24n fluidly connect pump
discharge port 22b to one of vessel inlets 14a-14n. Each blast line
18a, 18b, through 18n includes one of pinch valves 26a-26n operable
to vary the flow rate through respective blast lines 18a-18n and
one of blast control switches 28a-28n operable to control on-off
operation of respective blast lines 18a-18n. Delivery lines 24a-24n
each include one of solenoid valves 30a, 30b, through 30n that
provide on-off control of one of delivery lines 24a, 24b, through
24n and flow control valves 32a, 32b, through 32n operable to
adjust the flow rate through one of delivery lines 24a, 24b,
through 24n. Bypass line 34 fluidly connects pump discharge port
22b to vessel inlet 15 and includes bypass valve 35 to provide
on-off control of flow through bypass line 34. Compressed air is
provided to sprayers 20a-20n from compressed air source 36 via
compressed air lines 38a-38n. Compressed air and slurry combine
within sprayers 20a-20n before discharging to perform a wet
blasting operation. In order to manage the distribution of slurry
and compressed air delivered to sprayers 20a-20n, blasting system
10 further includes logic module 40 and time delay module 41
configured to control opening and closing of pinch valves 26a-26n,
solenoid valves 30a-30n, and bypass valve 35 in response to
actuated or unactuated states of blast control switches
28a-28n.
[0016] Blasting system 10 includes at least two blast lines 18a and
18b as well as at least two delivery lines 24a and 24b. However,
blasting system 10 can include more than two blast lines and
delivery lines. For instance, blasting system 10 can include an
arbitrary number (n) of blast lines, delivery lines, and associated
solenoid valves, flow control valves, pinch valves, compressed air
lines, and blast control switches represented by reference numerals
denoted by (n). Accordingly, as blasting system 10 is scaled to
include more than two blast lines and associated delivery lines,
the required volume of vessel 12 and the required capacity of pump
22 increases. Additionally, pump capacity can be increased by
arranging multiple pumps 22 in parallel while increased vessel
volume can be provided in a single vessel 12 or with multiple
vessels 12 linked together via pressure equalization pathways, as
will be discussed in subsequent embodiments.
[0017] Vessel (or blast pot) 12 is a pressure vessel manufactured
with a top opening and funnel to facilitate filling vessel 12 with
abrasive media. As implemented in blast system 10, and subsequently
described blast system embodiments, vessel 12 includes at least one
inlet 14 and at least two outlets 16a and 16b. Since vessel 12
receives fluid (e.g., water) from multiple delivery lines 24a-24n,
embodiments of the blast system that include a single inlet 14
typically include a manifold, a branch connection, or generally
another flow-combining element to permit fluid to flow into vessel
12 unimpeded by vessel inlet 14. In other embodiments, multiple
inlets 14a-n can be incorporated into vessel 12, for instance, one
inlet 14 for each delivery line 24a, 24b, through 24n, or any
intermediate number of inlets 14. In an installed orientation,
inlet or inlets 14 are positioned in the upper or top half of
vessel 12 opposite outlets 16a-16n positioned on the lower or
bottom half to facilitate fluid flow through vessel 12 and mixing
of abrasive media to produce slurry (i.e., an abrasive media mixed
with and suspended within a fluid) delivered through outlets
16a-16n.
[0018] Blast lines 18a, 18b, through 18n fluidly connect outlets
16a, 16b, through 16n to sprayers 20a, 20b, through 20n. First
blast line 18a includes pinch valve 26a and blast control switch
28a. Second blast line 18b includes pinch valve 26b and blast
control switch 28b and each additionally blast line 18n includes
pinch valve 26n and blast control switch 28n. Each blast line 18a,
18b, through 18n includes similar, if not identical, components
that are arranged and function in a similar, if not identical,
manner
[0019] Pinch valves 26a, 26b, through 26n each include a flexible
valve element (i.e., one of elements 42a, 42b, through 42n) that
can be displaced by an actuation force to vary the open area
through respective pinch valves 26a, 26b, through 26n. For
instance, pinch valve 26a includes flexible valve element 42a that
can actuated from a fully-open position (i.e., maximum open area)
to a fully-closed position to completely obstruct flow through
blast line 18a. Several methods of valve actuation can be used
including application of pneumatic or hydraulic pressure to a
backside or exterior surface of flexible element 42a. In other
embodiments, flexible element 42a can be actuated with an
electrically-actuated or other mechanically-driven actuator. An
interior surface of flexible element 42a forms a portion of the
flow path along blast line 18a. Accordingly, inward deflection of
flexible element 42a reduces flow area through pinch valve 26a and
outward deflection of flexible element 42a increases flow area
through pinch valve 26a. The remaining pinch valves 26b-26n
similarly include flexible valve elements 42b-42n and function in
the same manner as pinch valve 26a with flexible valve element 42a.
By using a pinch valve, the actuation components of the valve are
exterior to the flow path and, thus, are not subject to the wear
imposed on other types of valves resulting from a flow of abrasive
slurry.
[0020] Blast control switches 28a, 28b, through 28n are attached to
one of sprayers 20a, 20b, through 20n, each including an actuated
state and an unactuated state for selective control of a blasting
operation. Sprayer 20a receives compressed air through line 38a
from compressed air source 36. When blast control switch 28a has an
actuated state, a valve within sprayer 20a opens, permitting
compressed air to be discharged from sprayer 20a. In an unactuated
state, blast control switch 28a closes the sprayer valve to prevent
discharging compressed air. Additional sprayers 20b through 20n
installed with blasting system 10 are selectively controlled by
blast control switches 28b through 28n, respectively, such that
compressed air is delivered from source 36 via lines 38b-38n to
sprayers 20b-20n in the same manner as sprayer 20a and selectively
discharge compressed air via actuation of blast control switches
28b-28n in the same manner as blast control switch 28a.
[0021] Logic module 40, time delay module 41, or both modules 40
and 41 receive a blast signal indicative of blast control switch
28a in an unactuated state or an actuated state as schematically
indicated at 44a. Blast signal 44a can be a pneumatic or hydraulic
pressure transmitted along a conduit or tube to time delay module
40. For instance, upon actuation of blast control switch 28a,
pressure from compressed air within sprayer 20a can be sensed by
logic module 40 such that an ambient pressure or neutral gauge
pressure indicates an unactuated state of blast control switch 28a
and a pressure greater than a predefined threshold indicates an
actuated state of blast control switch 28a. In other embodiments,
signal 44a can be an analog signal (e.g., a voltage or current) or
digital signal (e.g., a high state or a low state) transmitted
along a wire or transmitted wirelessly to the time delay module 40.
Similarly, time delay module 40 receives blast signals 44b-44n
indicative of actuated or unactuated states of blast control
switches 28b-28n. As with blast signal 44a, blast signals 44b-44n
can be mechanical signals (i.e., pneumatic or hydraulic), analog
electrical signals (i.e., a voltage or current), digital electrical
signals (i.e., a high state or a low state), or a combination of
any of the foregoing types of signals.
[0022] Delivery lines 24a, 24b, through 24n fluidly connect pump
discharge port 22b to vessel inlets 14a-14n to provide fluid to
vessel 12. Within vessel 12, fluid mixes with abrasive media to
create slurry at vessel outlets 16a, 16b, through 16n. Delivery
line 24a includes solenoid valve 30a and flow control valve 32a,
each disposed along line 24a between pump discharge port 22b and
vessel inlet 14. In some examples, solenoid valve 30a is disposed
downstream of pump discharge port 22b and upstream from control
valve 32a. In other examples, the reverse configuration is used,
and solenoid valve 30a is disposed downstream of control valve 32a
and upstream from vessel inlet 14a. Each of the other delivery
lines 24b through 24n include one of solenoid valves 30b-30n and
one of flow control valves 32b-32n that are arranged as described
for delivery line 24a.
[0023] Solenoid valves 30a, 30b, through 30n are two position
valves having an open position for allowing flow through one of
delivery lines 24a-24n and a closed position for blocking flow
through one of delivery lines 24a-24n. Flow control valves 32a,
32b, through 32n include variable valve elements that can be
positioned to adjust a flow rate of water through delivery lines
24a, 24b, through 24n. For example, flow control valve 32a include
variable valve element 46a. In an open position of control valve
32a, variable valve element 46a allows water to flow through
delivery line 24a unobstructed by valve 32a and at a rate supplied
by pump 22. In a closed position of control valve 32a, variable
valve element 46a completely obstructs flow through delivery line
24a. At positions of control valve 32a between the open and closed
positions, variable valve element 46a partially obstructs flow
through delivery line 24a. The pressure drop that results from
variable valve element 46a partially obstructing flow reduces the
flow rate through delivery line 24a in proportion to the pressure
drop through flow control valve 32a. Each of the other flow control
valves 32b through 32n include one of variable valve elements
46b-46n, each of variable valve elements 46b-46n having an open
position, a closed position, and intermediate positions that adjust
the flow through respective delivery lines in the same manner as
flow control valve 32a.
[0024] Since blasting system 10 includes solenoid valves 30a-30n to
open or close flow through delivery lines 24a-24n, flow control
valves 32a-32n are adjusted to a set point within a range of
intermediate valve positions. Flow control valves 32a-32n can be
adjusted manually, such as via a knob, lever, electric or hydraulic
actuator, or can be adjusted automatically using an actuator
controlled by the time delay module 40. Typically, each flow
control valve 32a-32n will be adjusted to permit the same flow rate
of water through each delivery line 24a-24n for a selected blasting
operation.
[0025] Like delivery lines 24a-24n, bypass line 34 fluidly connects
pump discharge port 22b to vessel inlet 15 and includes bypass
valve 35. Bypass valve 35 is a two-position valve that opens or
closes bypass line 34. In the open position, fluid can flow from
pump discharge port 22b to vessel inlet 14. In the closed position,
fluid cannot flow to vessel inlet 15. In some examples, bypass
valve 35 is a solenoid valve. While any suitable flow area can be
selected for bypass line 34, bypass line 34 can have more flow area
than any one of delivery lines 24a-24n taken individually to permit
a higher flow rate into vessel 12 during some operating conditions.
For example, bypass line 34 can be sized to permit the maximum flow
rate deliverable by pump 22 with minimal pressure loss. To ensure
minimal pressure losses, bypass line 34 is sized such that the flow
velocity is approximately 1.52 meters per second (or about 5.0 feet
per second) or less at the maximum flow rate of pump 22.
[0026] Any suitable pump type can be used for pump 22. However,
fixed-displacement pumps are particularly suited for blasting
system 10. Such fixed-displacement pumps are known in the art and
provide a relatively constant volume of pressurized fluid at pump
discharge port 22b for each rotation of the pump impeller. Blasting
system 10 utilizes a single pump 22. However, as described in
subsequent embodiments, multiple pumps can be used.
[0027] To prepare blasting system 10 for operation, an operator
fills vessel (or blast pot) 12 with abrasive media and seals it
with a cover or plunger-style seal that presses against the
interior side of the vessel under pressure. Next, the operator
connects pump inlet 22a to a fluid source. Subsequently, at least
one of blast lines 18a-18n is connected to corresponding outlets
16a-16n of vessel 12. Flow control valves 32a-32n are set to a
target flow rate, which in some instances, is the same target flow
rate for each delivery line 24a-24n. The operator activates pump 22
to fill vessel 12 and delivery lines 24a-24n with water and
activates compressed air source 36 to pressurize lines 38a-38n. In
some instances, the operator prefills vessel 12 with water after
filling vessel 12 with abrasive media. Water continues to be pumped
into vessel 12 until a target pressure is obtained after which pump
22 operates intermittently to maintain pressure within delivery
lines 24a-24n and vessel 12. Automatic pressure stabilization can
be achieved with a pressure-responsive shut-off switch at the pump
or any other similar control method.
[0028] Vessel target pressure is selected to be a gauge pressure
that is less than the maximum design pressure of vessel 12 and
greater than a blast pressure required to perform a particular
blasting operation by at least a minimum amount to account for
system pressure losses between vessel 12 and sprayers 20a-20n. The
pressure differential between blast pressure and vessel pressure
can be affected by blast hose diameter, blast hose length, sprayer
nozzle size, blast pressure regulator setting, maximum deliverable
flow rate of compressed air source, maximum deliverable flow rate
of pump 22, and the number of blast lines in use. In some
instances, the target pressure is greater than or equal to 1.00 MPa
(145 psig) and less than or equal to 1.38 MPa (200 psig). In other
instances, the target pressure is greater than or equal to 1.14 MPa
(165 psig) and less than or equal to 1.33 MPa (193 psig). In still
other instances, the target pressure is approximately 1.28 MPa (185
psig).
[0029] Throughout operation of blasting system 12, logic module 40
and time delay module 41 govern the opening and closing of solenoid
valves 30a-30n, pinch valves 26a-26n, and bypass valve 35.
Initially, solenoid valves 30a-30n and pinch valves 26a-26n are in
the closed position and blast control switches 28a-28n have an
unactuated state. During the preparation phase, logic module 40
receives signals 44a-44n indicative of the unactuated states of
blast control switches 28a-28n and, in response, sends signal 46
causing bypass valve 35 to open.
[0030] The first blasting operation begins when an operator
actuates the first blast control switch to the actuated state. For
the purposes of explanation, the first blast control switch is
switch 28a, although any of the other blast control switches
28b-28n can be actuated first. When only one of the blast control
switches 28a-28n has an actuated state, blasting system 10
functions in much the same way as a conventional blasting system.
Accordingly, as soon as blast control switch 28a moves to the
actuated state, compressed air discharges from sprayer 20a that is
delivered from compressed air source 36 through line 38a.
Subsequently, logic module 40 receives signal 44a indicative of the
actuated state of blast control switch 28a. In response to signal
44a, logic module 40 opens solenoid valve 30a via opening signal
48a, opens pinch valve 26a via opening signal 50a, and closes
bypass valve 35 via closing signal 52. In this single sprayer
configuration, pump 22 drives fluid through delivery line 24a into
vessel 12 at inlet 14a according to the flow rate set by control
valve 32a. Fluid mixes with abrasive media within vessel 12 to
create slurry, which is delivered to blast line 18a via outlet 16a.
Slurry flows through blast line 18a at a rate governed by pinch
valve 26a to sprayer 20a. Within sprayer 20a, slurry mixes with
compressed air delivery through line 38a before discharging from
sprayer 20a to perform a wet blasting operation.
[0031] A second blasting operation begins when another operator
actuates a second blast control switch to an actuated state, for
example switch 28b. Upon actuation of second blast control switch
28b, compressed air flows through line 38b to sprayer 20b, and
logic module 40 receives second blast signal 44b indicative of the
actuated state of blast control switch 28b. In response to second
blast signal 44b, time delay module 41 transmits closing signal 54a
to pinch valve 26a associated with first sprayer 20a, causing pinch
valve 26a to close. Concurrently with closing signal 54a, logic
module 40 opens solenoid valve 30b via opening signal 48b. With
blasting system 10 in this configuration, slurry delivery to
sprayer 20a is stopped momentarily while compressed air flows
through both sprayers 20a and 20b. Additionally, fluid flows from
pump discharge port 22b into vessel 12 through delivery lines 24a
and 24b, increasing the pressure within vessel 12. After a
predefined time delay, time delay module 41 opens pinch valves 26a
and 26b via opening signals 50a and 50b, respectively, causing
slurry to be delivered to sprayers 20a and 20b. There, slurry mixes
with compressed air delivered to each sprayer 20a, 20b through
lines 38a, 38b before discharging from the sprayers during dual
blasting operations.
[0032] The duration of the time delay is dependent on various
parameters of system 10 including, volume and target pressure of
vessel 12, number and pressure loss through each delivery line, and
the volumetric flow rate delivered by pump 22. The time delay
duration is also dependent on the volumetric flow rate and pressure
delivered by compressed air source 36. The time delay duration is
selected based on these parameters, and in some embodiments, is
greater than a duration of transient operation during which
pressure within vessel 12 increases and pressure within compressed
air lines 38a-38b stabilizes. Typically, vessel pressure and air
pressure stabilize when each is within approximately 10% of target
values. In other examples, vessel pressure and air pressure are
considered stabilized when each pressure is within 5% of target
values. Further, the time delay duration can be a constant value.
Alternatively, some systems may have increased or decreased
transient operation depending on the number of actuated blast
control switches, and accordingly, the time delay module can be
configured to increase or decrease the time delay duration based on
the number of actuated blast control switches in the blasting
system.
[0033] Actuation of each subsequent blast control switch up to
blast control switch 28n occurs in a similar manner to actuating
second blast control switch 28b to the actuated state while first
blast control switch 28a is in the actuated state. Accordingly,
when an operator actuates any additional blast control switch 28n
into an actuated state, compressed air flows into sprayer 20n from
compressed air source 36 via line 38n and discharges from sprayer
20n. Additionally, actuating blast control switch 28n into an
actuated state transmits blast signal 44n indicative of the state
of blast control switch 28n to time delay module 40. Upon receiving
blast signal 44n, time delay module 41 transmits closure signal 54a
to first pinch valve 26a and transmits closure signal 54b to second
pinch valve 26b, causing pinch valves 26a and 26b to close and
momentarily stopping slurry flow into sprayers 20a and 20b.
Additionally, logic module 40 opens solenoid valve 30n by
transmitting opening signal 48n to valve 30n simultaneously or in
succession with closure signals 50a-50b. At this stage, solenoid
valves 30a, 30b, through 30n are in an open position, and fluid
flows from pump discharge port 22b into vessel 12 through delivery
lines 24a, 24b, through 24n at flow rates governed by flow control
valves 32a, 32b, through 32n. As a result, pressure within vessel
12 increases in much the same manner as described previously,
albeit by using more delivery lines than in the previous example
and, therefore, pressurization of vessel 12 occurs at an increased
rate. Again, after the predefined time delay, time delay module 41
opens pinch valves 26a, 26b, through 26n by transmitting opening
signals 54a, 54b, through 54n to respective valves 26a, 26b,
through 26n, causing slurry to be delivered to sprayers 20a, 20b,
through 20n. After the slurry mixes with compressed air within
sprayers 20a, 20b, through 20n, a wet abrasive mixture discharges
from each of the sprayers 20a, 20b, and 20n in a multi-sprayer
blasting operation.
[0034] When one of the operators actuates a blast control switch
into an unactuated state, logic module 40 acts to close the pinch
valve and solenoid valve associated with that particular blast
control switch. For example, when an operator moves blast control
switch 28n into the unactuated state, blast signal 44n becomes
indicative of an unactuated state rather than an actuated state.
Logic module 40 receives an indication of the changed blast control
signal 44n and, in response, transmits closure signal 56n to
solenoid valve 30n and transmits closure signal 50n to pinch valve
26n. Upon receiving closure signals 56n and 50n, solenoid valve 30n
and pinch valve 26n close, stopping the flow of water into vessel
12 through delivery line 24n and the flow of slurry through blast
line 18n. In this state, blast system 10 transitions from a
multi-spraying operation to a dual-spraying operation.
[0035] If in a subsequent operation, an operator actuates blast
control 28b to the unactuated state, logic module 40 receives an
indication of the unactuated state via blast signal 44b. In
response to the unactuated state of blast control switch 28b, logic
module 40 closes solenoid valve 30b and closes pinch valve 26b by
transmitting closure signals 56b and 50b to respective valves 30b
and 26b. Similarly, in response to actuating blast control switch
28a to an unactuated state, logic module 40 closes solenoid valve
30a and pinch valves 26a by transmitting closure signal 56a to
solenoid valve 30a and transmitting closure signal 50a to pinch
valve 26a. Once all blast control switches 28a-28n return to an
unactuated state and all pinch valves 26a-26n as well as all
solenoid valves 30a-30n are closed, logic module 40 opens bypass
valve 35 by transmitting opening signal 46. In this configuration,
the pressure within vessel 12 can be returned to the target
pressure between blasting operations. When blasting resumes with
the actuation of one of blast control switches 28a-28n, logic
module 40 closes bypass valve 35 by transmitting closing signal 52
to bypass valve 35. Thereafter, logic module 40 and time delay
sunmodule 41 respond to actuated or unactuated states of blast
control switches 28a-28n as described above.
[0036] While operations of blasting system 10 are described as
actuating blasting control switches 28a-28n in succession, logic
module 40 and time delay module 41 do not require blasting control
switches 28a-28n to be actuated in a particular order. Instead,
blast control switches 28a-28n can be actuated or unactuated in any
order. Further, multiple blast control switches 28a-28n can be
actuated simultaneously. Accordingly, any combination of actuated
and unactuated states of blast control switches 28a-28n is managed
by logic module 40 and time delay module 41 in a manner consistent
with the above disclosure.
[0037] In order to perform the above logic operations, logic module
and time delay module 41 can each include a network of analog logic
components, such as solenoid valves, shuttle valves, directional
control valves, AND valves, OR valves, arranged to perform the
logic described above. Actuation of the components can be pneumatic
or hydraulic as well as pilot-operated component actuation. For
example, AND logic functions can be achieved by arranging two or
more solenoid valves in series such that actuation of all valves in
the series is required to provide an output. In another example, OR
logic functions can be achieved by connecting two solenoid valves
in parallel and connecting the outputs of each valve to a shuttle
valve that permits a signal from either valve to pass to the output
while simultaneously preventing reverse flow through the unactuated
solenoid valve. In another OR logic example, multiple solenoid
valves can be connected in parallel such that the outputs are
joined together, each valve output having a check valve for
preventing reverse flow. AND logic and OR logic can also be
provided by a single valve equipped with two or more inputs and an
output, the valve element permitting flow to the output depending
on signals supplied to the inputs. Analog logic networks of this
type can be constructed in a variety of arrangements to perform the
functions of logic module 40 and time delay module 41.
[0038] Alternatively, one or both of logic module 40 and time delay
module 41 can include an electronic control module. The electronic
control module includes a receiving module configured to receive
one or more inputs, an output module configured to transmit one or
more outputs, a processor, and a storage unit (e.g., volatile or
non-volatile memory) encoded with instructions that, when executed
by the processor, perform the logic functions of logic module 40
and time delay module 41. In this instance, pneumatic or hydraulic
inputs can be used when the receiving module is appropriately
equipped with pressure-sensitive elements at the inputs. More
typically, the receiving module as well as the output module are
adapted to receive or transmit analog electric signals (e.g.,
voltage or current signals), digital electric signals (i.e., high
or low state signals), or a combination of analog and digital
electrical signals.
[0039] In some embodiments, logic functions preformed by logic
module 40 and time delay module 41 can be performed by independent
networks of analog logic components or electronic control modules
such that logic module 40 performs control operations of system 10
independently of time delay module 41. In this configuration, time
delay module 41 can receive blast signals independently of logic
module 40 and, in response, transmit opening signals and closing
signals to pinch valves 26a-26n as described in reference to system
10. In other embodiments, time delay module 41 can be integrated
into logic module 40 as a submodule whereby control operations of
logic module 40 and time delay module 41 are performed by a common
network of analog components or a common electronic control
module.
[0040] Blasting system 10 can include a multi-pump configuration in
lieu of the single pump configuration depicted by FIG. 1. FIG. 2 is
an example of multi-sprayer blasting system 10a incorporating a
multiple pump arrangement. Reference numbers used in FIG. 2 that
are described with respect to FIG. 1 represent the same components
and function in the same manner a previously described. However, in
a multi-pump configuration, blasting system 10a includes pumps 60a,
60b, and up to 60n in place of single pump 22 of the single pump
configuration, an example of which is depicted in FIG. 1. Each of
pumps 60a-60n are fluidly connected to a fluid source at intake
ports 62a-62n, and act on fluid received from the fluid source to
provide pressurized fluid at a desired flow rate through discharge
ports 64a-64n. Similarly, bypass line 34 can be supplied by pump
61, which receives fluid from the source through intake port 61a
and provides pressurized fluid at discharge port 61b. Using
multiple pumps arranged in parallel as shown in FIG. 2 increases
the maximum flow rate possible for system 10 relative to a
similarly sized single pump or, alternatively, permits the pump
capacity of each individual pump to be smaller than a single large
pump.
[0041] FIG. 3A depicts the effects of adding multiple outlets to a
conventional pressure vessel (or blasting pot). Like vessel 12,
vessel 12a includes multiple outlets 46a, 46b, 46c, and 46d
disposed on a bottom portion of vessel 12a when vessel 12a is in an
installed orientation. However, outlets 66a-66d are clustered in a
relatively small region of vessel 12a and, as such, slurry does not
discharge from vessel 12a at equal volumetric flow rates. As shown
by the relative length of each slurry flow arrow 68a, 68b, 68c, and
68d, outlets 66a and 66d located around a periphery of the outlet
region dispense more slurry than outlets 66b and 66c located
interior to outlets 66a and 66d. This skewed distribution results
from the relatively close proximity of a clustered outlet
configuration.
[0042] Separation of vessel outlets is critical to avoid unequal
distribution of slurry delivered through the outlets. Unequal
slurry distribution occurs when a pressure differential exists
between or among the outlets. Without addressing the pressure
differential, the blast line with the largest pressure differential
robs slurry from the other lines (or outlets) as illustrated in
FIG. 3A.
[0043] FIG. 3B depicts an exemplary pressure vessel (or blasting
pot) configuration that improves slurry delivery distribution and,
thus, is suitable for use in multi-spraying blasting systems (e.g.,
systems 10 and 10a). FIG. 3B depicts exemplary vessel 12b that
includes at least two outlets 70a and 70b and at least one internal
baffle 72. Outlets 70a and 70b are disposed in a bottom region of
vessel 12b when vessel 12b is in an installed orientation for the
same reasons described for vessel 12. Baffle 72 is disposed between
outlets 70a and 70b, extending inwards from an interior side of
vessel 12b to partition a portion of interior volume 74 of vessel
12b into volumes 74a and 74b. Because baffle 72 does not partition
vessel volume 74 completely, volume 74c fluidly communicates with
both volume 74a and 74b. For this reason, one or more inlets 14 of
vessel 12b are located at a boundary of vessel volume 74c. Outlet
70a extends through vessel 12b at a boundary of volume 74a such
that volume 74a is immediately adjacent to and communicates
directly with outlet 74a. Similarly, outlet 70b extends through
vessel 12b at a boundary of volume 74b such that volume 74b is
immediately adjacent to and communicates directly with outlet 74a.
Because baffle 72 prevents slurry from flowing directly between
outlets 70a-70b (i.e., directly from vessel volume 74a to vessel
volume 74b or vice versa), slurry discharged through outlet 70a is
approximately equal to slurry discharged through outlet 70b.
[0044] Baffle 72 seeks to equalize the amounts of slurry discharged
through outlets 70a and 70b and, thus, in the depicted example, is
positioned approximately half way between outlets 70a and 70b as
determined by a linear distance measured between geometric
centerlines of outlets 70a and 70b. However, depending on local
flow conditions, baffle 72 can be positioned at any position
between adjacent outlets that equalizes the slurry discharge rates
through two or more outlets.
[0045] Additionally, while a single baffle 72 is depicted by FIG.
3B, any number of baffles 72 can be arranged within vessel 12b. For
example, vessel 12b can include additional outlets 70c and 70d that
are arranged such that outlets 70a, 70b, 70c, and 70d are equally
spaced from each adjacent outlet to position each one of outlets
70a, 70b, 70c, and 70d in a different quadrant of vessel 12b. In
this example, baffle 72 can include two baffle walls that intersect
to form an X-shape or cross shape. Other configurations of baffle
72 may include a central wall circumscribing a central portion of
vessel volume 74 disposed at the bottom center of vessel 12b in the
installed condition (e.g., a cylindrical wall extending from the
bottom-most interior surface of vessel 12b). Multiple linear walls
extend outward from the central wall to the interior surface of
vessel 12b. With this configuration, an outlet can be
centrally-located at the bottom-most portion of vessel 12b and
additional outlets can be disposed within each of the volume
partitions defined by two adjacent linear walls and a portion of
the central wall.
[0046] FIG. 3C depicts another exemplary pressure vessel (or
blasting pot) configuration that can be used in multi-spraying
blasting systems. In this example, vessel 12c includes at least two
outlets (three outlets 76a, 76b, and 76c are shown), and vessel 12c
is sufficiently large to enable outlets 76a, 76b, and 76c to be
spaced by a minimum spacing criterion. For example, in the example
depicted by FIG. 3C, outlet 76a extends through vessel 12c at a
central location of a bottom-most portion of vessel 12c in an
installed orientation. Outlets 76b and 76c are spaced from outlet
76a such that approximately one third of cross-sectional area of
vessel 12c taken normal to a longitudinal direction of vessel 12c
is allocated to each of outlets 76a, 76b, and 76c. As a result,
slurry delivered through each outlet 76a, 76b, and 76c are
approximately equal or have less than or equal to a 5% flow
deviation.
[0047] FIG. 3D depicts yet another exemplary pressure vessel (or
blasting pot) configuration that can be used in multi-spraying
blasting systems. In this example, two or more vessels 12d are
joined together by pathways 78, each pathway 78 extending between
two vessels 12d placing an internal volume of each vessel 12d in
communication with another vessel 12d. For each vessel 12d, a
single outlet 80 is placed in a bottom region of vessel 12d when
vessel 12d is in an installed orientation. While two vessels 12d
are shown linked via pathway 78 in FIG. 3D, additional vessels 12d
can be joined to the assembly, each additional vessel 12d directly
linked to an adjacent vessel 12d and, thus, to every other vessel
12d in the assembly.
[0048] Whether one or multiple pathways 78 are used, each pathway
78 has a cross-sectional area sized to provide minimal pressure
drop between adjacent vessels 12d. The amount of permissible
pressure drop through pathway 78 will be system dependent and is
generally proportional to a flow velocity through the pathway 78.
Typically, flow velocities less than 1.52 meters per second (or
about 5.0 feet per second) result in a pressure loss through pathwa
blast signal y 78 that permits the discharging vessel pressure to
equalize with the stagnate vessel.
[0049] In addition to vessels depicted in FIGS. 3B, 3C, and 3D,
other suitable vessel configurations can include a combination of
aspects of one or more of the foregoing examples. For instance, a
baffle configuration from vessel 12b can be combined with spacing
requirements from vessel 12c to further improve uniformity of
slurry delivery among multiple vessel outlets. In another
combination, baffle requirements from vessel 12b, spacing
requirements from vessel 12c, or a combination of baffles and
spacing requirements can be combined with multiple vessel
arrangements depicted by FIG. 3D. Single vessel systems allow
blasting systems to have improved ease of use and a reduced form
factor relative to multi-vessel blasting systems whereas
multi-vessel blasting systems provide improved flow distribution
and blasting capacity.
[0050] Any of the vessel configurations can be used to facilitate
operation of a multi-sprayer blasting system such as those
described by this disclosure. Separation of vessel outlets provided
for by internal baffles, minimum spacing requirements, or
multi-vessel assemblies allow blast pressure differentials between
or among sprayers of up to 0.14 MPa (or about 20 psig) depending on
the size of the compressed air source. Furthermore, blasting system
configurations in accordance with aspects of this disclosure permit
multiple blast lines to operate independently and at varying
pressures.
Discussion of Possible Embodiments
[0051] The following are non-exclusive descriptions of possible
embodiments of the present invention.
[0052] A wet abrasive blasting system according to an exemplary
embodiment of this disclosure, among other possible things,
includes a vessel comprising a first outlet and a second outlet for
providing a slurry.
[0053] The wet abrasive system of the preceding paragraph can
optionally include, additionally, and/or alternatively, any one or
more of the following steps, features, configurations and/or
additional components:
[0054] A further embodiment of the foregoing wet abrasive blasting
system can further include a first sprayer operatively associated
with a first blast control switch.
[0055] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a second sprayer operatively
associated with a second blast control switch.
[0056] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a first pinch valve disposed
along a first blast line fluidly connecting the first sprayer to
the first outlet of the vessel.
[0057] A further embodiment of any of the foregoing wet abrasive
blasting system can further include a second pinch valve disposed
along a second blast line fluidly connecting the second sprayer to
the second outlet of the vessel.
[0058] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a logic module and a time
delay module.
[0059] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the logic module can be configured to
receive a first blast signal indicative of an actuated state of the
first blast control switch.
[0060] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the logic module can be configured to
receive a second blast signal indicative of an actuated state of
the second blast control switch.
[0061] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein upon receiving the second blast signal by
the logic module during the actuated state of the first blast
control switch, the time delay module can be configured to transmit
a first closure signal to the first pinch valve to close the first
pinch valve.
[0062] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein upon receipt of the second blast signal
by the logic module during the actuated state of the first blast
control switch, the time delay module can be configured to transmit
a second closure signal to the second pinch valve to maintain the
second pinch valve in a closed position.
[0063] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the time delay module can be configured
to transmit first and second opening signals to first and second
pinch valves, respectively, to open the first and second pinch
valves after a predetermined time delay starting upon receipt of
the second blast signal.
[0064] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a pump comprising an intake
port in fluid communication with a fluid source and a discharge
port.
[0065] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a first solenoid valve
positioned along a first delivery line fluidly connecting the pump
discharge port to an inlet of the vessel.
[0066] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a second solenoid valve
positioned along a second delivery line fluidly connecting the pump
discharge port to the vessel inlet.
[0067] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the logic module can be configured to
transmit a third opening signal to the first solenoid valve to open
the first solenoid valve upon receiving the first blast signal.
[0068] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the logic module can be configured to
transmit a fourth opening signal to the second solenoid valve to
open the second solenoid valve upon receiving the second blast
signal.
[0069] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the logic module can be configured to
transmit a third closure signal to the first pinch valve to close
the first pinch valve upon receiving a third blast signal
indicative of an unactuated state of the first blast control
switch.
[0070] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the logic module can be configured to
transmit a fourth closure signal to the first solenoid valve to
close the first solenoid valve upon receiving the third blast
signal.
[0071] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein upon receiving a fourth blast signal
indicative of an unactuated state of the second blast control
switch, the logic module can be configured to transmit a fifth
closure signal to the second pinch valve and transmit a sixth
closure signal to the second solenoid valve to close the second
pinch valve and the second solenoid valve.
[0072] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the logic module can be configured to
open a bypass valve positioned along a bypass line fluidly
connecting the pump discharge port to the vessel inlet upon
receiving blast signals indicative of unactuated states of all
blast control switches.
[0073] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a compressed air source.
[0074] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a first compressed air line
fluidly connecting the compressed air source to the first
sprayer.
[0075] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a second compressed air line
fluidly connecting the compressed air source to the second
sprayer.
[0076] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the first compressed air line can fluidly
connect with the first blast line at the first sprayer.
[0077] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the second compressed air line can
fluidly connect with the second blast line at the second
sprayer.
[0078] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the actuated state of the first blast
control switch can discharge compressed air from the first
sprayer.
[0079] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the actuated state of the second blast
control switch can discharge compressed air from the second
sprayer.
[0080] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the vessel can include a partial internal
partition, the internal partition defining a first volume that
includes the first outlet and a second volume that includes the
second outlet, and wherein the vessel includes a third volume
fluidly connecting the first volume to the second volume.
[0081] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a first regulating valve along
the first delivery line having a first adjustable valve element
operable to adjust a first flow rate within the first delivery
line.
[0082] A further embodiment of any of the foregoing wet abrasive
blasting systems can further include a second regulating valve
along the second delivery line having a second adjustable valve
element operable to adjust a second flow rate with the second
delivery line.
[0083] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the predetermined time delay can be
greater than a time required for the pump to increase a pressure
with the vessel to a target operating pressure sufficient to
operate the first sprayer and the second sprayer at a target flow
rate.
[0084] A further embodiment of any of the foregoing wet abrasive
blasting systems, wherein the time delay module can be a submodule
of the logic module.
[0085] A method according to another exemplary embodiment of this
disclosure, among other possible things, includes receiving a first
blast signal indicative of an actuated state of a first blast
control switch by a logic module and receiving a second blast
signal indicative of an actuated state of a second blast control
switch by the logic module. The method further includes
transmitting a first closure signal from a time delay module to a
first pinch valve and transmitting a second closure signal from the
time delay module to a second pinch valve upon receipt of the
second blast control signal by the logic module during the actuated
state of the first blast control switch.
[0086] The method of the preceding paragraph can optionally
include, additionally, and/or alternatively, any one or more of the
following steps, features, configurations and/or additional
components:
[0087] A further embodiment of the foregoing method, wherein the
first blast control switch can be operatively associated with a
first sprayer, the first sprayer fluidly connected to a first
outlet of a vessel by a first blast line.
[0088] A further embodiment of any of the foregoing methods,
wherein the second blast control switch can be operatively
associated with a second sprayer, the second sprayer fluidly
connected to a second outlet of the vessel by a second blast
line.
[0089] A further embodiment of any of the foregoing methods and can
further include transmitting a first opening signal from the time
delay module to a first pinch valve disposed along the first blast
line and transmitting a second opening signal from the time delay
module to the second pinch valve after a predetermined time delay
starting upon receipt of the second blast signal.
[0090] A further embodiment of any of the foregoing methods and can
further include transmitting, upon receipt of the first blast
signal, a third opening signal from the logic module to a first
solenoid valve positioned along a first delivery line fluidly
connecting a pump discharge port to an inlet of the vessel, wherein
the third opening signal opens the first solenoid valve.
[0091] A further embodiment of any of the foregoing methods and can
further include transmitting a third closure signal to the first
pinch valve upon receiving a third blast signal indicative of an
unactuated state of the first blast control switch, wherein the
third closure signal closes the first pinch valve.
[0092] A further embodiment of any of the foregoing methods and can
further include transmitting a fourth closure signal from the logic
module to the first solenoid valve upon receipt of the third blast
signal by the logic module, wherein the fourth closure signal
closes the first solenoid valve.
[0093] A further embodiment of any of the foregoing methods and can
further include transmitting a fifth closure signal from the logic
module to the second solenoid valve and transmitting a sixth
closure signal from the time delay module to the second pinch valve
upon receiving a fourth blast signal indicative of an unactuated
state of the second blast control switch, wherein the fifth closure
signal closes the second solenoid valve, and the sixth closure
signal closes the second pinch valve.
[0094] A further embodiment of any of the foregoing methods and can
further include opening a bypass valve using the logic module upon
receipt of signals indicative of closed states of all blast control
switches, wherein the bypass valve is positioned along a bypass
line fluidly connecting the pump discharge port to the vessel
inlet.
[0095] A further embodiment of any of the foregoing methods and can
further include supplying compressed air from a compressed air
source to the first sprayer along a first compressed air line in
response to the first blast control switch in the actuated
state.
[0096] A further embodiment of any of the foregoing methods and can
further include supplying compressed air from the compressed air
source to the second sprayer along a second compressed air line in
response to the second blast control switch in the actuated
state.
[0097] A further embodiment of any of the foregoing methods,
wherein the first and second compressed air lines fluidly connect
to the first and second blast lines, respectively, at the first and
second sprayers, respectively.
[0098] A further embodiment of any of the foregoing methods and can
further include setting a first flow rate through the first
delivery line with a first adjustable valve element of a first
regulating valve disposed along the first delivery line.
[0099] A further embodiment of any of the foregoing methods and can
further include setting a second flow rate through the second
delivery line with a second adjustable valve element of a second
regulating valve disposed along the second delivery line.
[0100] A further embodiment of any of the foregoing methods,
wherein the predetermined time delay is greater than a time
required for the pump to increase a pressure within the vessel to a
target operating pressure sufficient to operate the first sprayer
and the second sprayer at a target flow rate.
[0101] A further embodiment of any of the foregoing methods,
wherein the time delay module can be a submodule of the logic
module.
[0102] The described wet abrasive blasting systems and methods are
not limited to the particular embodiments, method steps, and
materials disclosed herein as such formulations, process steps, and
materials may vary somewhat. Moreover, the terminology employed
herein is used for the purpose of describing exemplary embodiment
only, and the terminology is not intended to be limiting since the
scope of the various embodiments of the present invention will be
limited only by the appended claims and equivalents thereof.
[0103] Therefore, while embodiments of the invention are described
with reference to exemplary embodiments, those skilled in the art
will understand that variation and modifications can be affected
within the scope of the invention as defined in the appended
claims. Accordingly, the scope of the various embodiments of the
present invention should not be limited to the above discussed
embodiments, and should only be defined by the following claims and
all equivalents.
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