Vapor blast system with fixed pot pressure

Abstract

A vapor abrasive blast system includes a pump for pumping a water stream to a pressure vessel for pressurizing the pressure vessel to a pot pressure. A water regulator is disposed to regulate the water stream to a fixed water pressure, such that the water stream entering the pressure vessel has the fixed water pressure. The pressure vessel contains a blasting mixture, comprising an abrasive media and water, for introduction to a compressed air stream and application to a substrate. The water entering the pressure vessel has the fixed water pressure to control the pot pressure. The water regulator is configured to output the water stream such that the fixed water pressure is greater than a compressed air pressure in the compressed air stream.

1 . A blasting system comprising:
 a pressure vessel configured to house a blast media;   a water line extending from a water source and connected to the pressure vessel to provide water to the pressure vessel;   a water pump disposed on the water line for driving a flow of water from the water source to the pressure vessel;   a water regulator disposed on the water line and configured to receive the flow of water and output a pressure regulated water flow having a regulated flow pressure, wherein a regulated flow pressure pressurizes the pressure vessel to a pressure vessel pressure; and   a blast line configured to convey a compressed air flow at an air pressure, wherein the compressed air flow is configured to receive a flow of media and water from the pressure vessel;   wherein the pressure vessel pressure is greater than the air pressure.   
     
     
         2 . The blasting system of  claim 1 , and further comprising:
 a media line extending from the pressure vessel and configured to transport the flow of media and water from the pressure vessel to the blast line.   
     
     
         3 . The blasting system of  claim 1 , wherein the water regulator is located downstream of the water pump. 
     
     
         4 . The blasting system of  claim 3 , wherein the regulated water pressure is about 1.27 MPa (185 psi). 
     
     
         5 . The blasting system of  claim 1 , and further comprising:
 a media line valve disposed on the media line upstream of the connection of the media line and the blast line, wherein the media line valve is configured to shift between an open position, wherein the media and water mixture is able to flow to the blast line, and a closed position, wherein the media and water mixture is prevented from flowing to the blast line.   
     
     
         6 . The blasting system of  claim 5 , wherein the media line valve comprises a pinch valve. 
     
     
         7 . The blasting system of  claim 1 , and further comprising:
 a selector valve disposed downstream of the water pump, wherein the selector valve is configured direct the water flow downstream of the selector valve.   
     
     
         8 . The blasting system of  claim 7 , wherein the selector valve is configured to direct the pressure regulated water flow to one of the pressure vessel and an accessory line. 
     
     
         9 . The blasting system of  claim 8 , wherein the water regulator is disposed downstream of the selector valve and upstream of the pressure vessel. 
     
     
         10 . The blasting system of  claim 7 , wherein the selector valve is a three-way valve. 
     
     
         11 . The blasting system of  claim 1 , and further comprising:
 a metering valve positioned downstream of the water regulator and configured to receive the pressure regulated water flow from the water regulator and meter a flow of the pressure regulated water flow to the pressure vessel.   
     
     
         12 . A method of blasting a substrate with a media, the method comprising:
 regulating a water flow pressure with a water regulator to generate a regulated water flow;   pumping the regulated water flow to a pressure vessel to pressurize the pressure vessel to a pressure vessel pressure having a fixed pressure point;   compressing an air stream to a blast pressure and flowing the air stream through a blast line and to a blasting apparatus, wherein the blast pressure is within a range between a minimum blast pressure and a maximum blast pressure; and   flowing media and water from the pressure vessel and into the air stream within the blast line and applying the combined flow of media, water, and air to a substrate, wherein the fixed pressure point is greater than the maximum blast pressure.   
     
     
         13 . The method of  claim 12 , wherein a pressure differential between the fixed pressure point and the blast pressure drives the media and water flow into the air stream. 
     
     
         14 . The method of  claim 12 , wherein the step of pumping a regulated water flow to a pressure vessel to maintain a pressure vessel pressure at a fixed pressure point further comprises:
 flowing a water flow to a water regulator, wherein the water regulator generates the regulated water flow; and   wherein the water regulator is disposed downstream of a water pump configured to pump the water to the pressure vessel.   
     
     
         15 . The method of  claim 14 , wherein the water regulator is disposed downstream of a selector valve configured to direct the water to the pressure vessel. 
     
     
         16 . The method of  claim 15 , wherein the step of pumping a regulated water flow to a pressure vessel to maintain a pressure vessel pressure at a fixed pressure point further comprises:
 flowing a system airflow through an air pressure regulator to generate a regulated system air flow, wherein the regulated system air flow has a maximum air pressure;   flowing the regulated system airflow to a water pump to power the water pump, wherein the maximum air pressure is equal to a maximum water pump operating pressure.   
     
     
         17 . The method of  claim 12 , wherein the step of pumping a regulated water flow to a pressure vessel to maintain a pressure vessel pressure at a fixed pressure point further comprises:
 flowing a system airflow through an air pressure regulator to generate a regulated system air flow, wherein the regulated system air flow has a fixed air pressure;   flowing the regulated system airflow to a water pump to power the water pump, wherein the fixed air pressure causes the water pump to output the regulated water flow.   
     
     
         18 . A vapor blast system comprising:
 a pressure vessel mounted to a support structure;   an enclosure mounted to the support structure, wherein the enclosure is configured to receive a flow of compressed air from a compressed air source, to receive a flow of water from a water source and to provide a regulated water flow to the pressure vessel, to receive a combined flow of media and water from the pressure vessel, and to output a combined flow of compressed air, water, and media; and   a water regulator disposed within the enclosure and configured to generate the regulated water flow;   wherein a regulated water flow pressure maintains a pressure vessel pressure above a compressed air pressure such that a pressure differential between the pressure vessel pressure and the compressed air pressure drives the combined flow of media and water into the flow of compressed air to generate the combined flow of compressed air, water, and media.   
     
     
         19 . The vapor blast system of  claim 18 , wherein the enclosure further comprises:
 a housing mounted to the frame;   a compressed air line extending into a first side of the housing;   a blast pressure regulator disposed on the compressed air line within the housing;   a blast line extending from the blast pressure regulator and exiting the housing through a blast media outlet extending through the first side;   a blast control line extending from the blast pressure regulator and connected to a control valve, wherein the blast control line controls the blast pressure regulator between a closed position, wherein compressed air is prevented from entering the blast line, and an open position, wherein compressed air is able to enter the blast line;   a pump control line extending from the control valve and connected to a water pump, and configured to power the water pump;   a water inlet line extending to the water pump and configured to provide a flow of water to the water pump;   a pressurization line extending from a water pump outlet and configured to provide the regulated water flow to the pressure vessel;   a blast media inlet extending into the enclosure and configured to receive a media hose extending from the pressure vessel; and   a flow hose extending from the blast media inlet and intersecting the blast line, wherein the flow hose provides the combined flow of media and water to the blast line to generate the combined flow of compressed air, media, and water;   wherein the water regulator is disposed on the pressurization line between the water pump and the pressure vessel, such that the water regulator receives a pump outlet water flow from the water pump and generates the regulated water flow.   
     
     
         20 . The vapor blast system of  claim 19 , and further comprising:
 a flow valve disposed on the flow hose and configured to actuate between a first position, wherein the flow hose is open, and a second position, wherein the flow hose is closed; and   wherein actuating the flow valve to the second position causes the water regulator to close, thereby returning the pressure vessel pressure to the fixed point.