Device And Method For Blasting A Suspension Onto Workpieces

Abstract

A device for irradiating a suspension on workpieces, the device including at least one pressure vessel for the suspension; at least one feed line for the suspension connected to the pressure vessel, the feed line is connected or can be connected to a radiation device; at least one valveswitched between the pressure vessel and the radiation device; at least one prechamber connected to the pressure vessel by a valve; at least one return line for the suspension, connected to the prechamber; and a line and a valve, by which the prechamber can be connected to a compressed air source or by which the prechamber is connected to a compressed air source. The valve between the prechamber and the pressure vessel is a check valve connected at its one upper, connection at a pressure vessel connection, which discharges into the pressure vessel through the bottom of the pressure vessel at the lowest point thereof, and which is connected at its other connection to the prechamber, wherein the flow direction of the check valve is directed toward the pressure vessel.

1 . A device, for blasting a suspension onto one or more workpieces, wherein the device encompasses:
 at least one pressure vessel,   at least one feed line for suspension that is connected to the pressure vessel, and is or can be connected to a blasting device,   at least one valve, which is switched between the pressure vessel and blasting device,   at least one prechamber, which is connected to the pressure vessel by a valve,   at least one return line for suspension, which is connected to the prechamber by a valve,   a line and valve, with which the prechamber can be connected to a compressed air source separate from the device, or with which the prechamber is connected to a compressed air source belonging to the device, characterized in that the valve between the prechamber and pressure vessel is a check valve, which at its one, upper, terminal is connected to a pressure vessel terminal that discharges into the pressure vessel through the floor of the pressure vessel, and that its other, lower, terminal is connected to the prechamber, wherein the passage direction of the check valve is directed toward the pressure vessel.   
     
     
         2 . A device, for blasting a suspension onto one or more workpieces, wherein the device encompasses:
 at least one pressure vessel,   at least one feed line for suspension that is connected to the pressure vessel, and is or can be connected to a blasting device,   at least one valve, which is switched between the pressure vessel and blasting device,   at least one prechamber, which is connected to the pressure vessel by a valve,   at least one return line for suspension, which is connected to the prechamber, by a valve,   a line and valve, with which the prechamber can be connected to a compressed air source separate from the device, or with which the prechamber is connected to a compressed air source belonging to the device, characterized in that the device encompasses a vacuum generating device, a vacuum injector or a vacuum pump, to which the prechamber is connected by means of at least one line and one valve, and/or that a pump is switched between the prechamber and return line, or a pump is connected to the end of the return line facing away from the prechamber, wherein the conveying direction of the pump during operation is directed toward the prechamber.   
     
     
         3 . The device according to  claim 2 , characterized in that the valve between the prechamber and pressure vessel is a check valve, which at its one, upper, terminal is connected to a pressure vessel terminal that discharges into the pressure vessel through the floor of the pressure vessel, at its lowest point, and that its other, lower, terminal is connected to the prechamber, wherein the passage direction of the check valve is directed toward the pressure vessel. 
     
     
         4 . The device according to  claim 1 , characterized in that the device encompasses a valve switched between the return line and prechamber, which involves a check valve, wherein this check valve at its one, upper, terminal is connected to a prechamber terminal that discharges into the prechamber through the floor of the prechamber, at its lowest point, and at its other, lower, terminal is connected to the return line, and wherein the passage direction of this check valve is directed toward the prechamber, and wherein it is provided that this check valve is structurally identical to the check valve switched between the prechamber and pressure vessel. 
     
     
         5 . The device according to  claim 1 , characterized in that the floor of the pressure vessel has a conical or curved shape, so that the cross section of the pressure vessel perpendicular to a vertical direction tapers downwardly, and/or that the floor of the prechamber has a conical or curved shape, so that the cross section of the prechamber perpendicular to a vertical direction tapers downwardly. 
     
     
         6 . The device according to  claim 1 , characterized in that the device encompasses at least one line and one valve, with which the pressure vessel can be connected to a compressed air source separate from the device, or with which the pressure vessel is connected to a compressed air source belonging to the device. 
     
     
         7 . The device according to  claim 1 , characterized in that the check valve switched between the prechamber and pressure vessel and/or the check valve switched between the return line and prechamber encompasses the following: A sealing element comprised of an elastically deformable material and a valve sleeve, which forms a seal seat that expands in the passage direction of the check valve, conically, wherein the sealing element forms a sealing edge extending along its periphery, which when the sealing element moves out of an open position in a direction toward the seal seat along the sealing edge, initially only along a circle, comes into contact with the seal seat. 
     
     
         8 . The device according to  claim 1 , characterized in that the sealing edge is bordered by two surfaces of the sealing element, which in a cross section oriented transverse to its circumferential direction run inclined to each other, at a right angle to each other, wherein both surfaces of the sealing element each include an acute angle with the surface of the seal seat in a cross section perpendicular to the circumferential direction of the sealing edge. 
     
     
         9 . The device according to  claim 1 , characterized in that the sealing element is accommodated in a longitudinally displaceable manner in the valve sleeve parallel to its longitudinal central axis, to which end the sealing element is connected with a guide that leaves one or several flow-through openings, and on their radially outer edge form a longitudinal guide with an inwardly pointing cylindrical surface of the valve sleeve. 
     
     
         10 . The device according to  claim 1 , characterized in that, when moved from an open position toward the seal seat, the sealing edge of the sealing element hits an annular zone of the seal seat spaced apart from the tapered end of the seal seat, and that pressurizing the sealing element against the seat seal triggers an elastic deformation of the sealing element, as a result of which the sealing element ( 66 ) abuts flat against the seal seat along its circumference. 
     
     
         11 . The device according to  claim 1 , characterized in that the feed line extends through the wall of the pressure vessel into its interior, wherein the distance between the mouth of the feed line and lowest point of the pressure vessel measures less than one eighth of the height of the interior of the pressure vessel. 
     
     
         12 . The device according to  claim 1 , characterized in that the check valve switched between the prechamber and pressure vessel is connected to a riser pipe, at its lower terminal in the installation position, which extends through the upper side wall of the prechamber into its interior, wherein the distance between the lower opening of the riser and the lowest point of the prechamber measures less than one eighth, of the height of the interior of the prechamber. 
     
     
         13 . The device according to  claim 1 , characterized in that the device encompasses a bypass line and a valve accommodated therein, wherein the one end of the bypass line discharges into the interior of the pressure vessel, at more than half of its height, inside of an ascending sifter placed in the pressure vessel, and wherein the other end of the bypass line discharges into the interior of the prechamber, at less than half of its height. 
     
     
         14 . The device according to  claim 1 , characterized in that the device encompasses two prechambers, two return lines and four, structurally identical, check valves, that the prechambers are connected in parallel with each other and, interposing a respective check valve, with the pressure vessel, and that a respective return line is connected to a respective prechamber, interposing a respective check valve. 
     
     
         15 . The device according to  claim 1 , characterized in that at least the pressure vessel, the prechamber or the prechambers, the check valve(s), the bypass line or bypass lines, the vacuum generating device and/or the pump as a combined assembly are situated in a shared or cubic housing, out of which the feed line and return line extend, that the assembly encompasses a compressed air terminal that is or can be connected to a compressed air source that belongs to the assembly or is separate from the assembly, that the prechamber is connected to the compressed air terminal by at least one valve, that the pressure vessel is connected to the compressed air terminal by at least one valve, and that the vacuum generating device and/or pump is connected to the compressed air terminal. 
     
     
         16 . The device according to  claim 1 , characterized in that the device is connected to a blasting cabin or encompasses a blasting cabin, wherein the respective blasting cabin exhibits an interior into which the feed line extends, and wherein the return line is connected to a collection receptacle of the blasting cabin for flowable media, wherein it is provided that the collection receptacle always be in a state of pressure equalization with the environment. 
     
     
         17 . A method for wet blasting one or several workpieces, comprising at least the following procedural steps:
 providing a device according to  claim 1 ,   providing a blasting cabin if the provided device encompasses no blasting cabin,   introducing the blasting device for the suspension and at least one longitudinal section of the supply line for the suspension into the interior of the blasting cabin,   connecting one end of the return line for the suspension to a collection receptacle of the blasting cabin for flowable media,   introducing suspension into the collection receptacle of the blasting cabin, characterized by the following procedural step:   aspirating suspension through the end of the return line connected to the collection receptacle of the blasting cabin, by generating a vacuum in the prechamber and/or by turning on a pump arranged between the collection receptacle and prechamber, and opening a vent valve connected to the prechamber.   
     
     
         18 . The method according to  claim 17 , characterized in that the method, subsequently, encompass at least:
 ending the aspiration of suspension through the end of the return line connected to the collection receptacle of the blasting cabin,   supplying compressed air into the prechamber at least partially filled with suspension, and opening a vent valve connected to the pressure vessel, for example which is a throttle valve or a pressure relief valve.   
     
     
         19 . The method according to  claim 17 , characterized in that the method, subsequently, encompass at least:
 aspirating suspension through the end of the return line connected to the collection receptacle of the blasting cabin, by generating a vacuum in the prechamber and/or turning on a pump arranged between the collection receptacle and prechamber, and opening a vent valve connected to the prechamber,   as this takes place, supplying compressed air to generate overpressure in the pressure vessel at least partially filled with suspension,   and, given an overpressure in the pressure vessel, at least intermittently opening the valve allocated to the feed line so as to blast suspension onto one or several workpieces.   
     
     
         20 . The method according to  claim 17 , characterized in that the method, subsequently, encompass at least:
 turning off the compressed air supply in the pressure vessel,   generating overpressure in the prechamber by supplying compressed air into the prechamber,   given an overpressure in the prechamber, at least intermittently opening the valve allocated to the feed line, and blasting suspension onto one or several workpieces, and at least intermittently opening a vent valve connected to the pressure vessel.   
     
     
         21 . The method according to  claim 20 , characterized in that the steps of:
 turning off the compressed air supply in the pressure vessel,   generating overpressure in the prechamber by supplying compressed air into the prechamber,   given an overpressure in the prechamber, at least intermittently opening the valve allocated to the feed line, and blasting suspension onto one or several workpieces, and at least intermittently opening a vent valve connected to the pressure vessel are repeatedly executed alternately in time relative to the steps of:   aspirating suspension through the end of the return line connected to the collection receptacle of the blasting cabin, by generating a vacuum in the prechamber and/or turning on a pump arranged between the collection receptacle and prechamber, and opening a vent valve connected to the prechamber,   as this takes place, supplying compressed air to generate overpressure in the pressure vessel at least partially filled with suspension,   and, given an overpressure in the pressure vessel, at least intermittently opening the valve allocated to the feed line so as to blast suspension onto one or several workpieces.   
     
     
         22 . The method according to  claim 17 , characterized in that the method, subsequently, encompass at least:
 generating overpressure in the pressure vessel by supplying compressed air into the pressure vessel and opening the valve allocated to the bypass line, so that at least the liquid phase of the suspension or the suspension is transported from the pressure vessel into the prechamber,   once a specific level has been reached in the prechamber, ending the supply of compressed air into the pressure vessel and generating overpressure in the prechamber by supplying compressed air, and   in the process at least intermittently opening a vent valve connected to the pressure vessel and/or opening the valve allocated to the feed line for blasting suspension out of the blasting device.   
     
     
         23 . The method according to  claim 17 , characterized in that suspension is blasted onto one or several workpieces, wherein the weight ratio between the overall solid phase contained in the suspension and the overall liquid phase contained in the suspension has the value 1. 
     
     
         24 . A method according to  claim 1 , characterized in that suspension is blasted onto one or several workpieces, wherein the weight ratio between the overall solid phase contained in the suspension and the overall liquid phase contained in the suspension is greater than 0.5.