Patent Application
20230201999
Not Applicable
Not Applicable
Various wet abrasive blast machines and vapor blast machines (collectively “WAB” machines) are well known in the surface cleaning industry. Typically, a hydraulic side and a pneumatic side combine to enable blasting of pressurized fluids to scour and clean surfaces. A blast pot, containing grit, is pressurized by water pumped from a standalone water tank into the blast pot to maintain a pressure therein. Pneumatic pressure is thence generated via an air compressor into a blast hose via a piping manifold connected to the blast pot by a slurry hose. Slurry (grit and water) from the blast pot is thence introduced into the airflow in the blast hose to jet a spray of pressurized fluid containing grit against a targeted surface. The effect is to spray a high velocity stream of grit particles to scour and clean the targeted surface. Depending on the grit used and the pressures employed, the surface may be scoured to remove paint, rust, residue, chemicals, oxides, and other surface elements or contaminants, to expose, restore, or refinish the surface.
During blasting operations, introduction of grit from the blast pot into the airstream is controlled by a pinch valve operating at the juncture of the slurry hose and the blast hose. When an operator enacts a switch at the blast hose nozzle, typically a deadman switch to require active engagement, the pinch valve is automatically opened to release pressure on the hydraulic side whereby slurry is forced into the airstream and thence carried, at pressure, for blasting.
As seen in the art, water from the standalone tank is also applied to a rinse cycle after blasting operations have ceased. The present state of the art controls application of rinse water by requiring manual shut-off of a ball valve disposed upon the slurry hose whereby water is introducible into the airstream while the slurry from the blast pot is excluded. This presents several problems and inefficiencies when blasting. First, a second operator is generally required to tend the blast pot and respond to signals from the operator to disengage the hydraulic side for rinsing to commence. Slurry remnant in the slurry hose downstream from the ball valve, and up to the blast hose nozzle, must then be evacuated by the rinse stream before rinsing operations can properly commence. This results in wasted time, resources, wear on the ball valve, and additional manpower—especially when switching between blasting and rinsing operations frequently since the ball valve must be manually set each time between blasting and rinsing and the slurry in the slurry hose downstream from the ball valve and in the blast hose must be evacuated.
What is needed is a control circuit feeding back to the pinch valve from the blast hose proper wherein the operator of the blast hose is enabled remote control of a pinch to switch between blasting and rinsing operations without having to employ use of the upstream ball valve in sealing off the blast pot, nor deactivate the pumps pressurizing the hydraulic circuit(s), nor deactivating the compressor(s) pressurizing the pneumatic circuit. Thus, singlehanded blasting operations are enabled and immediate switching between rinse and blasting cycles is effectuated more efficiently with the hydraulic and pneumatic circuits maintained at pressure.
The present invention relates to an improved wet abrasive blast machine with remote control rinse cycle, and more particularly, to an improved wet abrasive blast machine with remote control rinse cycle that includes a control circuit enabling remote control of blasting and rinsing operations. The control circuit directs a pilot air signal, drawn off the pneumatic circuit and fed between various configurations, to control a main blast air inlet valve, a rinse solenoid valve, a pinch air block valve, and a pinch valve whereby an operator, and a pilot at the blast hose nozzle, are enabled to remotely control introduction of slurry into the blast stream and immediately switch between, and cease, blasting and rinse cycles.
The present improved wet abrasive blast machine with remote control rinse cycle has been devised to enable an operator to switch between blast and rinse cycles remotely and at the nozzle of the blast hose. The present improved wet abrasive blast machine obviates the need for a second party (or other party) to control introduction and exclusion of slurry from the blast hose, instead enabling a single user or pilot operating the blast nozzle to control immediate cycling between blasting and rinsing.
Wet abrasive blasting (also known as “vapor blasting”) is established and well known in the art. Insoluble grit particles, typically sand-sized silicates and/or other grits, are delivered from a blast pot by a pressurized non-compressible fluid (typically water) pumped into the blast pot. The fluid acts as a carrier, displacing the grit from the blast pot as a slurry into a slurry hose for communication to a blast hose wherein an airstream sprays the slurry forth at pressure to clean and scour surfaces. Rinsing is enabled by shutting off the slurry hose to prevent slurry from entering the blast hose while pumping water bypassing the blast pot for dispersal via the airstream.
Wet abrasive blasting, therefore, employs at least three circuits—two hydraulic circuits and a pneumatic circuit. Switching between rinsing and blasting is typically accomplished in tandem—a user operating the blast hose at the point of operations (known as a “pilot” in the art) is typically distally disposed relative the blast pot, which may be large and heavy. A second operator, therefore, is required to manually engage at least one valve upon the slurry hose to prevent slurry from entering the blast hose during rinse cycles. Employment of the second party for such purposes increases costs associated with wet abrasive blasting and causes delays to accommodate communication back and forth between the pilot and the said second party.
Further, the valve employed in switching between blast and rinse cycles is typically the slurry hose shut-off valve, a ball valve that operates to seal off the slurry house interiorly and wholly throttle the circuit. Blasting ejects coarse grit particles which rapidly wear and degrade such components that contact the slurry stream. Use of the ball valve to disable blasting and enable rinsing is therefore an inefficient use of an expensive part. Present day, slurry hose shut-off valves employed in this fashion are one of the most frequently replaced parts in the surface cleaning industry. Operation of a pinch valve to close of the slurry hose in a guillotine-like enclosure prevents direct wear on the valve. Since the interior of the slurry hose is smooth and disposed along the direction of flow, wear is significantly lessened and the hose itself considerably less expensive to replace anyway.
The sheer quantity of fluid and slurry used in wet abrasive blasting necessitates large vessels for storage of the water supply and for pressurizing the slurry. Such large vessels restrict a range of motion whereby operations are predominantly limited by the length of the blast hose proper. Surface cleaning requires ambulation by the pilot to cover the targeted area, which may include vertical and other non-horizonal surfaces requiring elevation of the pilot (such as, for example, when cleaning the interior of hulls of large ocean-faring vessels). As presently seen in the art, the pilot typically communicates with a second party to switch between blast and rinse cycles at the slurry shut-off valve and also, oftentimes, with a third party who tends the water supply, grit supply, and acts to control the air-compressor required to maintain the airstream in the pneumatic circuit. Often, disabling the pneumatic circuit is effectuated by turning off the compressor, thereby throttling the pneumatic circuit and blast and rinse cycles and requiring reboot and a time lapse while pressure is restored in the system.
The present invention, therefore, addresses and obviates these and other inefficiencies, enabling switching between the rinse and blast cycles remotely and, in a preferred embodiment, directly from the nozzle of the blast hose by a pilot actively engaging in surface cleaning operations. The pilot, therefore, need not arrest blasting or rinsing and await receipt of an all clear signal, but can control action between each of a first and second hydraulic circuit by action of a control circuit that, in a preferred embodiment set forth herein, operates via configuration of an air pilot signal directed within a branch circuit fed by the pneumatic circuit and controllable by a series of manual controls located remotely and at the nozzle of the blast hose.
An embodiment is set forth herein that also contemplates an electrically operated control circuit by effecting electric switching of the various valves to direct the air pilot signal between controlling branch circuits, as will be described subsequently.
In an embodiment set forth herein, such switching of various valves to direct the air pilot signal between controlling branch circuits is also controlled pneumatically, by the same air pilot signal. It should be understood by persons of ordinary skill in the art that such discussion of such embodiment is entered herein to engender clarity in exemplifying a singular configuration of the present invention, with particular and specific examples by way of explanation, and that variations of parts and arrangements of parts informing the following disclosure are determined and contemplated to be within scope of the inventive step set forth herein where consistent with the overall motivation and intent exemplified and described.
Discussing now an example embodiment, then, air is drawn off the pneumatic circuit upstream of a main blast air inlet valve to feed the control circuit. The air is routed at approximately 100 psig through an instrument air filter-regulator that regulates air pressure and removes moisture and any particulates. The control circuit is thus operable pneumatically, by a pilot signal of air pressure (“air pilot signal” and, when contemplating electrical alternatives, just “pilot signal”) maintained and cycled within the control circuit during blast and rinse operations and fed directly from the pneumatic circuit. (It is noted that alternative pressures are contemplated for operating the invention, and may be employed while practicing the invention. The range cited herein is not meant to be limiting. A pressure differential merely need be maintained between each of the first and second hydraulic circuits and the pneumatic circuit to ensure introduction of slurry (or water) into the blast airstream.)
A deadman remote control handle is disposed at the blast hose nozzle to enable manipulation of the pilot signal, to actuate valve actuators that effectively switch between the blast and rinse cycles, and to disable blasting if released. The deadman remote control handle is a normally-closed, two-way, manually operable pneumatic block valve that receives a control pressure signal from an upstream deadman supply air regulator via a twin line remote control tubing that connects the control circuit with the blast nozzle.
A main control valve-relay is disposed in the control circuit and functions as the main on-off control for the blast air cycle. The main control valve-relay is a pneumatic five-port, four-way, pneumatic air pilot controlled valve with one normally-closed and one normally-open port. When the deadman remote control handle is squeezed by a pilot operating the blast hose nozzle, air is routed through a branch circuit via an emergency stop valve to an actuator upon the main control valve-relay. Pressurization by airflow incident this actuator causes the main control valve-relay to actuate and switch airflow from a normally-open port to a normally-closed port, thereby enabling the blast cycle, as will be described subsequently.
Airflow through the normally-closed port of the main control valve-relay sends a pilot signal to a branch circuit that controls the main blast air inlet valve (to activate airflow through the pneumatic circuit) and concurrently instates a pilot signal at a normally-closed port of a rinse control valve-relay. When this normally-closed port of the rinse control valve-relay is closed, the air pilot signal thereat is preempted.
Airflow introduced into the control circuit is likewise fed in parallel into the rinse control valve-relay from the air filter-regulator. During blast operations, airflow is directed through a normally-open port inside the rinse control valve-relay. Airflow through the normally-open port of the rinse control valve-relay is directed to actuate a pinch air block valve disposed in fluid communication with the main control valve-relay and the pinch valve operative upon the slurry hose. When actuated, the pinch air block valve opens. When the pinch air block valve is open and airflow through the main control valve-relay is active through the normally-closed port therein, airflow is exhausted through a pinch valve exhaust to depressurize the branch circuit controlling the pinch valve, thereby ensuring the pinch valve is open whereby the first hydraulic circuit is enabled. Thus, blasting operations are enabled when the deadman remote control handle is squeezed (or activated).
The rinse control valve-relay is actuated by a pilot signal diverted thereto by action of a remote rinse control valve disposed at the blast hose nozzle (the remote rinse control valve may of course be remotely located as well). Manual action at the remote rinse control valve diverts airflow into a branch circuit to pressurize an actuator actuating the rinse control valve-relay to switch airflow through the rinse control valve-relay normally-closed port. When the normally-closed port of the rinse control valve-relay is opened by the pilot signal sent from a remote rinse control valve, airflow pressurizes a branch circuit controlling a rinse water solenoid valve that enables waterflow through the second hydraulic circuit. Concurrently, airflow is preempted from the pinch air block valve by closure of the normally-open valve in the rinse control valve-relay, preventing airflow therethrough, which thence causes closure of the pinch air block valve and prevention of exhaust from the pinch valve control circuit. The pinch valve is thus pressurized and actuates to cease the first hydraulic circuit by clamping the slurry hose. The rinse cycle is now enabled.
Switching between blast and rinse cycles is effective immediately by an operator or pilot switching the remote rinse control valve. Pressure potential at both the first and second hydraulic circuits is uninterrupted. Pressure within the pneumatic circuit is uninterrupted. Only throughflow is ceased or enabled, thereby enabling immediate switching between blast and rinsing cycles.
Release of the deadman remote control handle ceases blast operations—the main control valve-relay switches airflow to the normally-open port whereby the pinch valve is immediately actuated to cease throughflow of the first hydraulic circuit and airflow is not fed via the normally-closed port to actuate the main blast air inlet valve thereby disabling the pneumatic circuit.
Thus has been broadly outlined the more important features of the present improved wet abrasive blast machine with remote control rinse cycle so that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated.
Objects of the present improved wet abrasive blast machine with remote control rinse cycle, along with various novel features that characterize the invention are particularly pointed out in the claims forming a part of this disclosure. For better understanding of the improved wet abrasive blast machine with remote control rinse cycle, its operating advantages and specific objects attained by its uses, refer to the accompanying drawings and description.
With reference now to the drawings, and in particular
Referring to
A schematic of the present wet abrasive blast machine with remote control rinse cycle 10 is depicted in
The present improved wet abrasive blast machine with remote control rinse cycle 10, therefore, includes a first hydraulic circuit 20 that directs waterflow from fresh water supply 22 to blast pot 24, slurry hose 26, and blast hose 100. The first hydraulic circuit 20 therefore routes waterflow from fresh water supply 22 into blast pot 24 by action of air-operated double diaphragm fill pump 70 and piston blast pump 72. Water entered into blast pot 24 is therefore subjected to pressure by action of pumps 70, 72 and serves to displace and convey grit particles storable interior blast pot 24 into slurry hose 26 for dispersal into an airstream generated interior to blast hose 100 by action of a pneumatic circuit 40, as will be described subsequently. Pressure of approximately 125 to 150 psig is attained throughout the first hydraulic circuit 20. High pressure fluid containing grit and water, or “slurry”, is thus dispersible ejected from the nozzle 102 of the blast hose 100 to scour and clean surfaces, as is seen in the present state of the art. It is noted that alternative pressures are contemplated for operating the invention, and may be employed while practicing the invention. The range cited herein is not meant to be limiting. A pressure differential merely need be maintained between each of the first and second hydraulic circuits and the pneumatic circuit to ensure introduction of slurry (or water) into the blast airstream.
Introduction of slurry from slurry hose 26 into the high-pressure airstream, which is maintained in blast hose 100 by action of the pneumatic circuit 40, is controllable by operation of slurry hose shut-off valve 80—an isolation valve operating a full port ball valve disposed upstream of the conjunction between slurry hose 26 and blast hose 100. In the present state of the art, this shut-off valve 80 is typically operated manually to disable throughflow of slurry into the blast hose 100 thereby to arrest grit application and scouring operations. Thus, when the slurry hose shut-off valve 80 is actuated to a closed position, the first hydraulic circuit 20 is arrested and slurry is ceased from introduction into the blast hose 100 until the slurry shut-off valve 80 is actuated to an open position. Slurry shut-off valve 80 is therefore a throttle, disabling the first hydraulic circuit 20 until opened manually.
In the present invention 10, however, a pinch valve 82, disposed downstream of slurry hose shut-off valve 80 but still upstream of blast hose 100, operates a sliding guillotine-style valve to compress the slurry hose 26 and pinch-off throughflow of slurry. Activation and deactivation of the first hydraulic circuit 20 is thus controllable by action of pinch valve 82, particularly when switching between blast and rinse cycles, as will be described subsequently. Pinch valve 82 is disposed in operational communication with the control circuit 50, as will be described subsequently, and is thus operable remotely by a user piloting the apparatus 10 at a distally located panel or by the pilot controlling blast operations at the nozzle 102 of the blast hose 100.
A second hydraulic circuit 30 is disposed connecting waterflow from fresh water supply 22 to blast hose 100 without the blast pot 24 or the slurry hose 26, thereby bypassing the grit contained in the blast pot 24 altogether. This second hydraulic circuit 30 therefore delivers waterflow to blast hose 100 by an alternate route bypassing blast pot 24 and slurry hose 26 to introduce water into the pressurized airstream maintained in blast hose 100 by action of the pneumatic circuit 40 when active. Water is drawn from fresh water supply 22 immediately downstream of piston blast pump 72, and forced through rinse shut-off valve 32, a throttle; rinse water solenoid valve 34, controllable via the control circuit; and rinse water check valve 36, to prevent backflow; and into blast hose 100.
Rinse water shut-off valve 32 is an instrument ball valve disposed to throttle water supply into the second hydraulic circuit 30 when necessary. Rinse water solenoid valve 34 is an air actuated solenoid valve disposed to control throughflow of water branched into the second hydraulic circuit 30 by action of piston blast pump 72. The rinse water solenoid valve 34 engages when a pilot air signal is received at actuator 34a from the control circuit 50, fed via a normally-closed port 60b disposed upon rinse control valve-relay 60 operative in the control circuit 50, as will be described subsequently.
High-pressure ejection of water from the blast hose 100 nozzle 102 absent grit particles is therefore enabled for use in a rinse cycle. Throughflow of water bypassing blast pot 24 is thus controllable via control of the rinse water solenoid valve 34. Peculiar to this invention 10, switching between blast cycles and rinse cycles is enabled remotely, even directly from the nozzle 102 of the blast hose 100, by action of a control circuit 50, as will be described subsequently, while maintaining active operation of pumps 70, 72 and, as discussed below, compressor 42.
The pneumatic circuit 40 is configured to control throughflow of pressurized air through the blast hose 100. Air is introduced into the pneumatic circuit 40 by action of compressor 42 and is passed to blast hose 100 through main blast air inlet valve 44, main air check valve 46, and blast pressure throttling valve 48. The main blast air inlet valve 44 includes an air activated solenoid to control actuating and de-actuating the main blast airstream. In the present invention 10, action of the main blast air inlet valve 44 is controllable remotely, from a panel 500 and/or from the nozzle 102 of the blast hose 100 by a pilot operating the device 10. Airflow diverted from a normally-closed port 54b upon a main control valve-relay 54 maintains the main blast air inlet valve 44 in an open condition whereby the blast airstream is enabled to vent via the blast hose nozzle. Throughflow of the blast airstream in the pneumatic circuit is thus controllable by controlling the main blast air inlet valve 44.
In an embodiment of the present invention 10, a portion of airflow introduced into the pneumatic circuit 40 is fed upstream of the main blast air inlet valve 44 to feed the control circuit 50 which, in this embodiment, functions pneumatically, as will be explained hereinbelow.
The control circuit 50 enables remote switching between the first and second hydraulic circuits 20, 30 and cessation of the first and second hydraulic circuits 20, 30 and the pneumatic circuit 40 by remote control. Air is branched from the pneumatic circuit 40 to pneumatically control pinch valve 82, rinse control valve-relay 60, rinse water solenoid valve 34, and main blast air inlet valve 44, by manual action effected remotely at a deadman remote control handle 106, disposed at the nozzle 102 of the blast hose 100, and/or at controls disposed upon panel 500, as will be discussed hereinbelow. A pilot is therefore enabled to control cycling between a rinse cycle and a blast cycle manually remotely, and/or at the nozzle 102 of the blast hose 100, without the need of a second (or other) party to operate the pinch valve 82 or slurry shut-off valve 80 directly. The pilot may also cease blasting and rinsing altogether while maintaining pressure within the system to enable immediate resumption of blasting and/or rinsing when the deadman remote control handle 106 is re-engaged, as will be described subsequently.
Discussing now the first hydraulic circuit 20, water is drawn from fresh water supply 22, typically a water storage vessel or tank disposed in open communication with the first and second hydraulic circuits 20, 30. Water is pumped into the blast pot 24 by action of air operated double diaphragm pump 70 and piston blast pump 72. Water is thus pressurized to approximately 125 to 150 psig within blast pot 24 (alternative pressures are contemplated as within the scope of the invention). Grit, essentially non-soluble particles of varying size (most often sand-sized silicates), additional to or stored within blast pot 24, is thus conveyed under pressure in the waterflow to slurry hose 26. It should be noted that other-sized particles and materials are contemplated as within scope of the art.
Water pumped to blast pot 24 is pumped through a series of valves to prevent backflow to the water supply. Fill pump shut-off valve 84 and blast pump shut-off valve 86 are full port ball valves and serve as isolation valves enabling manual shut-off of waterflow into blast pot 24 and the first and second hydraulic circuits 20, 30 when necessary. A fill pump check valve 88 and blast pump check valve 90 prevent reverse flow of water or contaminants into the double diaphragm fill pump 70 and the piston blast pump 72 respectively. Water pumped to blast pot 24 is also metered through the grit metering valve 92 to control the outlet grit mixture volume. This maintains one-directional, regulated flow of fluid through the first hydraulic circuit 20.
Water pumped into the blast pot 24 therefore conveys grit to the slurry hose 26 under pressure at approximately 125 to 150 psig (or other pressure, so long as such pressure exceeds the pressure operative in the blast hose). Grit is thus conveyed at pressure as a slurry into the blast hose 100 via the slurry hose shut-off valve 80 and pinch valve 82. Pinch valve 82, an air-actuated sliding guillotine-style valve that controls introduction of the slurry into the blast airstream for disbursement through the blast hose 100 during blast cycle operations, is disposed in operational communication with the control circuit 50, as will be described subsequently.
The second hydraulic circuit 30 draws water downstream of piston blast pump 72 through a branch circuit bypassing the blast pot 24 to provide water absent grit for application during the rinse cycle. Water fed into the second hydraulic circuit 30 is controlled by action of rinse water solenoid valve 34, an air-actuated solenoid valve that enables on-off control of the second hydraulic circuit 30 by enabling and disabling throughflow of water therethrough. Reverse flow of water to the rinse water solenoid valve 34 is controlled by action of rinse water check valve 36 preventing backflow therethrough. The second hydraulic circuit 30 may also be shut-off by manual action at the rinse water shut-off valve 32, an isolation valve installed upstream from the rinse water solenoid valve 34 to disable waterflow through the second hydraulic circuit 30 when necessary and thereby throttle the second hydraulic circuit 30.
Blasting operations are controlled by a blast airstream instated by the pneumatic circuit 40. Air is supplied via action of compressor 42, pressurizing airflow to approximately 100 to 125 psi. Air supply is forced through main blast air inlet valve 44, main air check valve 46, and blast pressure throttling valve 48 to blast hose 100. Main blast air inlet valve 44 is an air-actuated solenoid valve providing on-off control of the main blast airstream. Main blast air inlet valve 44 engages when receiving an air pilot control signal from normally-closed port 54b of the main control valve-relay 54 operational within the control circuit 50, as will be described subsequently.
In the preferred embodiment set forth herein, the control circuit 50 is pneumatically operated throughout, to control diversion of airflow to effectuate valve configurations required to sustain the blast cycle, the rinse cycle, and cessation of both blast and rinse cycles. However, electrical operation to control the same valve configurations is contemplated as within scope of this invention whereby airflow of the control circuit 50 is diverted between said valve configurations by means of electrical switching, as will be described subsequently in presentation of an alternate embodiment hereinbelow.
In the preferred embodiment, then, air is fed through the control circuit 50 upstream of the main blast air inlet valve 44. This branched pneumatic circuit supplies a pilot air signal to control actuation of main blast air inlet valve 44, rinse water solenoid valve 34, rinse control valve-relay 60, and pinch valve 82, by a pilot operating the apparatus 10. Air is drawn from the pneumatic circuit 40 and routed into the control circuit 50 through instrument an air filter-regulator 52, to regulate air pressure within the control circuit 50, filter particulates, and remove moisture via an internal moisture separating spin filter and condensate drain with automatic float valve. Normal pressure within the control circuit 50 is typically set at around 75 to 100 psig. Alternative ranges of pressure are contemplated as within scope of the present invention.
Main control valve-relay 54 functions as the main on-off control for the blast air cycle and is controlled by diversion of airflow via the deadman remote control handle 106. Main control valve-relay 54 is a five-port, four-way pneumatic air pilot controlled valve with one normally-closed and one normally-open port. When the deadman remote control handle 106 is squeezed (or, in alternate embodiments contemplated as within scope of this invention, switched to an “on” position) airflow is diverted through branch circuit 50a, through the emergency stop valve (configured to prevent airflow therethrough when depressed by manual action thereat) and into the main control valve-relay 54. When the main control valve-relay 54 receives the air pilot signal from the deadman remote control handle, airflow is switched through normally-closed port 54b, thus pressurizing branch circuit 50b, which actuates actuator 44a upon the main blast air inlet valve 44, thereby enabling throughflow of air in the pneumatic circuit.
Simultaneously, air is directed in parallel through the rinse control valve-relay 60, a five-port, four-way pneumatic air pilot controlled valve having one normally-open port 60a and one normally-closed port 60b. When the remote rinse control valve 62, manually operable by the pilot, is disposed in an “off” configuration, airflow is directed through normally-open port 60a of the rinse control valve-relay 62 which enters pinch air block valve 58 and is exhausted when the main control valve-relay 54 is running through the normally-closed port 54b. Exhaustion of the pinch air block valve 58 effectuates exhaustion of air pressure from branch circuit 50a thereby de-actuating actuator 82a releasing the pinch valve 82. Thus, slurry is enabled throughflow for blasting.
The rinse cycle is enabled when remote rinse control valve 62 is switched to an “on” position. Remote rinse control valve 62 is a three-way “L” port diverter valve, with two separated fluid connections with a common center port. When the remote rinse control valve 62 is turned to the “on” position, airflow is diverted to activate actuator 60c which thence switches throughflow through the remote rinse control valve 62 to the normally-closed port 60b. Airflow then travels along branch circuit 50b to actuate rinse water solenoid valve 34 to enable throughflow of water through the second hydraulic circuit 30. When airflow is diverted through normally-closed port 60b, normally-open port 60a is thence closed whereby absence of pressure deactivates pinch air block valve 58, causing closure thereat. When the pinch air block valve 58 is closed, pressure in branch circuit 50a is maintained, actuator 82a is actuated, and pinch valve 82 is thereby engaged to prevent throughflow of slurry into the blast hose.
Referring particularly now to
As shown specifically in
Simultaneously, air coming from the air filter-regulator 52 is drawn in parallel through rinse control valve-relay 60 normally-open port 60a, thereby engaging pinch air block valve 58, which opens. Since airflow through the main control valve-relay 54 is being directed through normally-closed port 54b, airflow into the pinch air block valve 58 is exhausted through pinch valve exhaust 58a, which pinch valve exhaust 58a is otherwise shut off when airflow through the main control valve-relay 54 is operating through the normally-open port 54a. Air is thus exhausted from branch circuit 50d whereby actuator 82a is de-actuated and pinch valve 82 is rendered open.
Because remote rinse control valve is in the “off” position, airflow directed diagrammatically south (see
Discussing now
In the rinse cycle, the control air pilot signal is configured to engage pinch valve 82, maintain main blast air inlet valve 44 open, and maintain rinse water solenoid valve 34 open. Airflow is again directed upstream of main blast air inlet valve 44 into the control circuit 50 as set forth above in the previous description of
Because airflow through main control valve-relay 54 is operative through normally-closed port 54, air flows diagrammatically south (see
Discussing now
When deadman remote control handle 106 is released (or otherwise switched to an “off” configuration) airflow within branch circuit 50a is ceased. Resultantly, pressure at the main control valve-relay 54 reverts airflow to normally-open port 54a, directing airflow into branch circuit 50d to actuate actuator 82a which engages pinch valve 82 thereby sealing off the first hydraulic circuit 20 at the slurry hose 26. Since the remote rinse control valve 62 is disposed in the “off” configuration, airflow is prevented from action interior to branch circuit 50b, whereby airflow through rinse control valve-relay 60 reverts to normally-open port 60a. This configuration therefore prevents airflow into branch circuit 50c, thereby preventing actuation of rinse water solenoid valve 34 whereby the second hydraulic circuit 30 is impeded. Airflow is thus directed via normally-open port 60a to the pinch air block valve 58, which is caused to open. Because airflow from the main control valve-relay 54 is active through the normally-open port 54a, airflow through the pinch air block valve 58 is not exhausted but, instead, diverted into branch circuit 50d, thereby actuating actuator 82a and pinch valve 82. Since airflow through normally-closed port 54b is likewise prevented, airflow is preempted from branch circuit 50c whereby actuator 44a is de-actuated and the main blast air inlet valve 44 is rendered closed. Thus, all circuits 20, 30, and 40, are effectively ceased when a pilot releases the deadman remote control handle 106 (or otherwise switches it to an “off” position). It should be noted, however, that pumps 70, 72 and compressor 42 are still active whereby engagement of the deadman remote control handle 106 may immediately start up blasting operations again.
The emergency stop valve 56 enables emergency cessation of blast operations. The emergency stop valve 56 is a normally-open valve when positioned in the “run” position. Depression of a detent effectuates closure off the valve 56 and isolates air returning from the deadman remote control handle 106 to prevent pressurizing the actuator 54c on the main control valve-relay 54. Simultaneously, air is exhausted from the emergency stop valve 56 to the main control valve-relay 60, which causes the main control valve-relay 60 to disengage, preventing the air signal to main blast air inlet valve 44 and thereby ceasing blast operations.
As shown in
In this alternate embodiment, branch circuits 50a and 50b are essentially rendered via electrical circuits and switches in lieu of directed airflow pressurizing actuators 54c, 60c to switch configurations of normally-open ports 54a, 60a, and normally-closed ports 54b, 60b. In such an embodiment, however, the remaining components of the control circuit 50 are substantially similar, and the first hydraulic circuit 20, the second hydraulic circuit 30, and the pneumatic circuit 40 remain the same.
In this alternate embodiment, switching is effected electrically. Thus, when the deadman remote control handle 106 is actuated, a contact (not shown) enables conduction of current in now-electric branch circuit 50a to switch airflow interior to the main control valve-relay 54. Likewise, when the remote rinse control valve-relay 62 is moved to the “on” position, contacts (not shown) enable conduction of current through now-electric branch circuit 50b to effect switching of airflow through normally-closed port 60b interior to the rinse control valve-relay 60.
Blast pot 24 is disposed mounted to frame member 600 to enable portability of the present embodiment. Funnel top member 602 enables filling of blast pot 24 with grit (shown in greater detail in, and discussed hereinbelow with reference to,
Blast pressure gauge 522 shows pressure in the blast stream and hopper pressure gauge 524 shows the pressure inside blast pot 24. Emergency stop button 526 activates emergency stop valve 56 to disable blast operations when engaged. Control 528 enables manual control of grit metering valve 92 to selectively control concentration of grit entering slurry hose 26. Blast pump switch 530 enables immediate manual deactivation of blast pump 72.
High volume, low pressure, double diaphragm fill pump 70 feeds water from the supply (not shown) to blast pot 24 via water fill line 504. Low volume high pressure piston blast pump 72 pressurizes blast pot 24 for introduction of slurry into the slurry hose 26. Pinch valve 82 operates guillotine-style valve to pinch slurry hose 26 and cease throughflow of slurry in the first hydraulic circuit 20 in response to air pilot signal via control circuit 50d (see
This continuing application claims the benefit of application Ser. No. 16/540,798 filed on 14 Aug. 2019.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16540798 | Aug 2019 | US |
| Child | 18175587 | US |
