Wet abrasive blast machine with remote control rinse cycle
11590631 · 2023-02-28
Inventors
Cpc classification
B24C7/0038
PERFORMING OPERATIONS; TRANSPORTING
International classification
Abstract
An improved wet abrasive blast machine with remote control rinse cycle enables a pilot operating the apparatus to control remote switching between blast and rinse cycles directly, for example from a nozzle of a blast hose or from a panel. A first and second hydraulic circuit and a pneumatic circuit are controllable via communication with a control circuit which is operable remotely to direct a configurable pilot signal between various valve states. In a preferred embodiment, the control circuit is powered pneumatically via a branch circuit fed from the pneumatic circuit. Switching between to configurations is effected by directing an air pilot signal between airflows interior to a series of valves. In an alternate embodiment switching airflows between configurations is effected electrically.
Claims
1. An improved wet abrasive blast machine with remote control rinse cycle enabling remote control of blasting operations between a rinse cycle and a blast cycle, said improved wet abrasive blast machine comprising: a first hydraulic circuit communicating waterflow to a blast pot, a slurry hose, and a blast hose; a second hydraulic circuit communicating waterflow to the blast hose to bypassing the blast pot and the slurry hose; a pneumatic circuit communicating outflow of air through the blast hose; and a control circuit comprising an air pilot signal directable to enable remote switching between the first and second hydraulic circuits and to cease operations of said first and second hydraulic circuits and operation of the pneumatic circuit without deactivating action of at least one pump pressurizing said first and second hydraulic circuits nor action of a compressor feeding air to the pneumatic circuit; wherein immediate cycling between a rinse cycle and a blast cycle is controllable remotely, and by a pilot operating said blast hose, to rapidly switch between blasting and rinsing operations when actively engaged in surface cleaning.
2. The improved wet abrasive blast machine with remote control rinse cycle of claim 1 wherein the air pilot signal is fed from airflow introduced into the pneumatic circuit upstream of a main blast air inlet valve.
3. The improved wet abrasive blast machine with remote control rinse cycle of claim 2 wherein the pilot air signal is configurable as airflow to pressurize and depressurize each of a plurality of actuators, said plurality of actuators comprising: an actuator disposed actuating the main blast air inlet valve configured in operational communication within the pneumatic circuit, said actuator opening the main blast air inlet valve when pressurized by incident airflow; an actuator disposed actuating a pinch valve upon the slurry hose configured in operational communication within the first hydraulic is circuit, said actuator closing the pinch valve when pressurized by incident airflow; an actuator actuating a pinch air block valve configured in operational communication within the control circuit, said actuator opening said pinch air block valve when pressurized by incident airflow; and an actuator actuating a rinse solenoid valve configured in operational communication with the second hydraulic circuit, said actuator opening said rinse solenoid valve when pressurized by incident airflow.
4. The improved wet abrasive blast machine with remote control rinse cycle of claim 3 wherein the air pilot signal is further configurable to control switching between: at least one normally-open port and at least one normally-closed port interior to a main control valve-relay configured in operational communication in the control circuit; and at least one normally-open and at least one normally-closed port interior to a rinse control valve-relay configured in operational communication within the control circuit.
5. The improved wet abrasive blast machine with remote control rinse cycle of claim 4 wherein airflow directed through the normally-open port in the main control is valve-relay feeds a branch circuit to pressurize the actuator controlling the pinch valve and thereby cease throughflow of slurry to the blast hose.
6. The improved wet abrasive blast machine with remote control rinse cycle of claim 5 wherein airflow directed through the normally-open port in the rinse control valve-relay feeds a branch circuit that pressurizes the actuator actuating the pinch air block valve, whereby the pinch air block valve is opened.
7. The improved wet abrasive blast machine with remote control rinse cycle of claim 6 wherein airflow through the pinch air block valve is merged into the branch circuit pressurizing the actuator controlling the pinch valve when airflow is concurrent through the normally-open port in the main control valve-relay.
8. The improved wet abrasive blast machine with remote control rinse cycle of claim 7 wherein airflow directed through the normally-closed port in the main control valve-relay feeds a branch circuit that pressurizes the actuator actuating the main blast air inlet valve and concurrently sends an air pilot signal to the normally-closed port of the rinse control valve-relay.
9. The improved wet abrasive blast machine with remote control rinse cycle of claim 8 wherein the control circuit further comprises a remote rinse control valve operable between an “off” position and an “on” position, whereby movement of the remote rinse control valve to the “on” position diverts airflow into a branch circuit to switch airflow within the rinse control valve-relay from the normally-open port to the normally-closed port whereby airflow is directable to pressurize the actuator actuating the rinse water solenoid valve and enable waterflow through the second hydraulic circuit.
10. The improved wet abrasive blast machine with remote control rinse cycle of claim 9 wherein airflow directed through the normally-closed port of the main control valve-relay and the normally-open port in the rinse control valve-relay concurrently actuates the pinch air block valve to open and wherein the pinch valve is released via exhaustion through a pinch valve exhaust, which pinch valve exhaust is otherwise closed when airflow through the main control valve-relay is configured through the main control valve-relay's normally-open port.
11. The improved wet abrasive blast machine with remote control rinse cycle of claim 10 wherein the pinch air block valve maintains pressure within the branch circuit controlling actuation of the pinch valve when said pinch air block valve is closed whereby the pinch valve is maintained closed.
12. The improved wet abrasive blast machine with remote control rinse cycle of claim 11 wherein manual action at a deadman remote control handle disposed upon a nozzle of the blast hose feeds a branch circuit that pressurizes the actuator controlling airflow through the normally-closed port of the main control valve-relay whereby manual control of the remote rinse control valve between the “on” and “off” positions therefore switches airflow through the rinse control valve-relay to control waterflow through the second hydraulic circuit and the first hydraulic circuit while maintaining operation of the pneumatic circuit.
13. The improved wet abrasive blast machine with remote control rinse cycle of claim 12 wherein release of the deadman remote control handle prevents airflow from the branch circuit pressurizing the actuator of the main control valve-relay wherein airflow reverts to the normally-open port therein, thereby ceasing pressurization of the actuator actuating the main blast air inlet valve and disabling the pneumatic circuit, whereby airflow pressurizes the actuator actuating the pinch valve to disable the first hydraulic circuit.
14. The improved wet abrasive blast machine with remote rinse cycle of claim 4 wherein switching airflow between the normally-open and normally-closed ports interior to both the main control valve-relay and the normally-open and normally-closed ports interior to the rinse control valve-relay is effectuated electrically instead of pneumatically.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Figures
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14) TABLE-US-00001 Parts List 10 Improve wet abrasive blast machine 20 first hydraulic circuit 22 fresh water supply 24 blast pot 26 slurry hose 30 second hydraulic circuit 32 rinse shut-off valve 34 rinse water solenoid valve 34a actuator 36 rinse water check valve 40 pneumatic circuit 42 compressor 44 main blast air inlet valve 44a actuator 46 main air check valve 48 blast pressure throttling valve 50 control circuit 50a branch circuit (deadman North) 50b branch circuit (deadman south) 50c branch circuit (main blast air inlet valve) 50d branch circuit (pinch valve) 50e branch circuit (rinse water solenoid valve) 52 air filter-regulator 54 main control valve-relay 54a normally-open port 54b normally-closed port 54c actuator 56 emergency stop valve 58 pinch air block valve 58a pinch air block valve exhaust 58b pinch air block actuator 60 rinse control valve-relay 60a normally-open port 60b normally-closed port 60c actuator 62 remote rinse control valve 70 double diaphragm fill pump 72 piston blast pump 80 slurry hose shut-off valve 82 slurry hose pinch valve 82a actuator 84 fill pump shut-off valve 86 blast pump shut-off valve 88 fill pump check valve 90 blast pump check valve 92 grit metering valve 100 blast hose 102 nozzle 104 deadman regulator 106 deadman remote control handle 500 inlet panel 502 connection port to main blast air inlet valve 504 fill line 506 blast inlet pressure gauge 508 dump valve 509 air dump valve 510 utility line 511 cleanout aperture 512 faucet 514 outlet panel 516 blast hose attachment aperture 518a pneumatic control line port: rinse signal 518b pneumatic control line port: supply air 518c pneumatic control line port: return air 520a control line: rinse 520b control line: supply 520c control line: return 522 blast pressure gauge 524 hopper pressure gauge 526 emergency stop button 528 control (grit metering valve) 530 blast pump switch 532 control circuit air inlet tubing 534 remote rinse control valve switch 600 frame member 602 funnel top member 604 top aperture 606 seating stopper 608 raised top plate
DETAILED DESCRIPTION OF THE DRAWINGS
(15) With reference now to the drawings, and in particular
(16) Referring to
(17) A schematic of the present wet abrasive blast machine with remote control rinse cycle 10 is depicted in
(18) The present improved wet abrasive blast machine with remote control rinse cycle 10, therefore, includes a first hydraulic curcuit 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.
(19) 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 50, 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 curcuit 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 curcuit 20 until opened manually.
(20) 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 therethrough. Activation and deactivation of the first hydraulic curcuit 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.
(21) 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.
(22) 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.
(23) 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.
(24) 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.
(25) 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.
(26) 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.
(27) 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.
(28) 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.
(29) 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.
(30) 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.
(31) 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.
(32) 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.
(33) 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.
(34) 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.
(35) 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.
(36) 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.
(37) Referring particularly now to
(38) As shown specifically in
(39) approximately 75 to 100 psig. Alternative pressures are contemplated as within scope of the invention. Air is passed through deadman regulator 104 to deadman remote control handle 106. Because the deadman remote control handle 106 is engaged (or switched to an “on” position in alternate embodiments contemplated consistent with this invention), airflow is diverted diagrammatically north (see
(40) 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.
(41) Because remote rinse control valve is in the “off” position, airflow directed diagrammatically south (see
(42) Discussing now
(43) 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
(44) Because airflow through main control valve-relay 54 is operative through normally-closed port 54, air flows diagrammatically south (see
(45) Discussing now
(46) 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 curcuit 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.
(47) 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.
(48) As shown in
(49) In this alternate embodiment, branch circuits 50a and 50b are essentially rendered via electrical circuits and switches in lieu of directed airflow pressurizing to 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.
(50) 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.
(51)
(52) 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,
(53)
(54) 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.
(55)
(56) 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 curcuit 20 in response to air pilot signal via control circuit 50d (see
(57)
(58)