Abrasive suspension jet cutting system having reduced system wear and process materials reclamation

Abstract

An abrasive suspension jet cutting system, the system includes a cutting head. The cutting head has a feed assembly, nozzle and acceleration cavity therebetween. The feed assembly has a slurry orifice and a shielding fluid orifice. Within the acceleration cavity abrasive slurry and shielding fluid are accelerated together from the slurry orifice to the nozzle while maintaining a shielding fluid barrier substantially unmixed with the abrasive slurry around the abrasive slurry. The cutting head is further configured to have both the slurry and shielding fluid pass substantially unmixed through the nozzle thereby limiting nozzle wear. A wear control system is provided to reduce wear of the nozzle and other system components during start and stop. The system may further include a reclamation system that collects and reclaims used abrasive particles and fluid and returns them back to the cutting head to be reused thereby reducing system operational costs.

What is claimed is: 
     
         1 ) A system for abrasive suspension jet cutting using an abrasive slurry and a shielding fluid;
 comprising:   a) a feed assembly having a slurry orifice and a shielding fluid orifice;   b) a nozzle;   c) an acceleration cavity between the feed assembly and the nozzle; and   d) wherein within the acceleration cavity the abrasive slurry and shielding fluid are accelerated together from the slurry orifice to the nozzle while maintaining a shielding fluid barrier substantially unmixed with abrasive slurry around the abrasive slurry, and wherein both the slurry and shielding fluid pass substantially unmixed through the nozzle.   
     
     
         2 ) The system as recited in  claim 1 , further comprising only a single pump to commonly energize the abrasive slurry and the shielding fluid to move both through the acceleration cavity and out the nozzle. 
     
     
         3 ) The system as recited in  claim 1 , further comprising an abrasive slurry reclamation system. 
     
     
         4 ) The system as recited in  claim 3 , wherein the abrasive slurry reclamation system includes a collection system to collect used slurry and shielding fluid, a separator to separate out reusable abrasive particles from used slurry and shielding fluid to produce reclaimed slurry and reclaimed shielding fluid, and a recirculation system to reintroduce the reclaimed slurry and the reclaimed shielding fluid to the feed assembly. 
     
     
         5 ) The system as recited in  claim 4 , further including a conditioner system to maintain rheological properties of the base fluid. 
     
     
         6 ) The system as recited in  claim 5 , wherein the conditioner system includes a rheological test system and a rheological modifier system. 
     
     
         7 ) The system as recited in  claim 4 , further including a fines filter to remove waste particles from shielding fluid. 
     
     
         8 ) The system as recited in  claim 4 , further including a fluid reclamation system. 
     
     
         9 ) The system as recited in  claim 1 , wherein the nozzle includes a nozzle entrance orifice; wherein the acceleration cavity narrows from the slurry orifice to the nozzle entrance orifice to provide hydrodynamic focusing within the acceleration cavity. 
     
     
         10 ) The system as recited in  claim 9 , wherein the acceleration cavity has a taper angle of greater than 15-degrees to minimize mixing within the nozzle. 
     
     
         11 ) The system as recited in  claim 1 , wherein the nozzle includes a nozzle length and nozzle orifice diameter; wherein the nozzle length is less than the nozzle orifice diameter. 
     
     
         12 ) The system as recited in  claim 1 , further comprising an abrasive wear control system. 
     
     
         13 ) The system as recited in  claim 12 , wherein the abrasive wear control system includes a slurry to shielding fluid volume flow regulator and a valve system that allows reverse flow of abrasive slurry through the cutting head to reduce nozzle wear. 
     
     
         14 ) The system as recited in  claim 1 , wherein the abrasive slurry has an abrasive slurry volume, wherein the shielding fluid has a shielding fluid volume, wherein the abrasive slurry volume and shielding fluid volume define a total volume, wherein the system provides that the abrasive slurry volume is greater than 30-percent of the total volume as the abrasive slurry exits the nozzle. 
     
     
         15 ) The system as recited in  claim 1 , further including the abrasive slurry and the shielding fluid formed from a same base fluid. 
     
     
         16 ) The system as recited in  claim 15 , wherein the abrasive slurry and the shielding fluid have matched flow characteristics that is at least one from the group consisting of viscosity and shear rate viscosity dependence. 
     
     
         17 ) The system as recited in  claim 15 , wherein the abrasive slurry and the shielding fluid have the same flow modifying additive. 
     
     
         18 ) The system as recited in  claim 17 , wherein the flow modifying additive is at least one from the group consisting of a xanthan gum, guar gum, cellulose derivatives, polyacrylamide, gelatin, bentonite, another natural, another synthetic polymer and clay. 
     
     
         19 ) The system as recited in  claim 15 , wherein the base fluid consists substantially of water and a suspension agent. 
     
     
         20 ) A system for abrasive suspension jet cutting using abrasive slurry having abrasive particles contained within a fluid; comprising:
 a) a cutting head having a nozzle to eject a jet of slurry at high velocity; and   b) a reclamation system that collects used abrasive particles and fluid and then returns reclaimed abrasive particles and fluid to the cutting head.   
     
     
         21 ) The system as recited in  claim 20 , further comprising a catch tank agitator to mix the used fluid and abrasive particles. 
     
     
         22 ) The system as recited in  claim 20 , further comprising a collection system to collect used abrasive particles and fluid. 
     
     
         23 ) The system as recited in  claim 20 , further comprising a separator system to separate out reusable abrasive particles from used fluid to produce reclaimed slurry. 
     
     
         24 ) The system as recited in  claim 23 , wherein the separator system includes a separator. 
     
     
         25 ) The system as recited in  claim 24 , wherein the separator includes a filter housing having a dilute slurry inlet, shielding fluid outlet, a concentrated slurry outlet and a filter, wherein the filter is located between the dilute slurry inlet and shielding fluid outlet. 
     
     
         26 ) The system as recited in  claim 25 , wherein the separator further includes a separator agitator. 
     
     
         27 ) The system as recited in  claim 25 , wherein the filter moves within the filter housing between the dilute slurry inlet and the shielding fluid outlet. 
     
     
         28 ) The system as recited in  claim 23 , wherein the separator system further includes a fluid property controller that monitors at least one from the group consisting of density and viscosity of concentrated slurry. 
     
     
         29 ) The system as recited in  claim 23 , wherein the separator system further includes a flow meter. 
     
     
         30 ) The system as recited in  claim 24 , wherein the separator includes a filter housing having a dilute slurry inlet, a first shielding fluid outlet, a second shielding fluid outlet, a concentrated slurry outlet, a first filter and a second filter; wherein the first filter is located between the dilute slurry inlet and first shielding fluid outlet, wherein the second filter is moveable between dilute slurry inlet and second shielding fluid outlet. 
     
     
         31 ) The system as recited in  claim 29 , wherein the separator further includes a separator agitator. 
     
     
         32 ) The system as recited in  claim 24 , wherein the separator system includes a filter housing having a first dilute slurry inlet, a second dilute slurry inlet, a first stationary filter, a second filter, a plunger, a first reclaimed shielding fluid outlet, a second reclaimed shielding fluid outlet, a first concentrated slurry outlet, and a second concentrated slurry outlet; wherein the first filter is located between the first dilute slurry inlet and the first reclaimed shielding fluid outlet; wherein the second filter is located between the second dilute slurry inlet and the second reclaimed shielding fluid outlet; wherein the plunger is located between the first filter and the second filter. 
     
     
         33 ) The system as recited in  claim 24 , wherein the separator system further includes a filter housing having a dilute slurry inlet, a first shielding fluid outlet, a second shielding fluid outlet, a concentrated slurry outlet, a stationary filter, a movable filter and movable shuttle puck; wherein the stationary filter is located between the dilute slurry inlet and the second shielding fluid outlet; wherein movable filter is between the dilute slurry inlet and the first shielding fluid outlet; wherein the movable filter and movable shuttle puck can move together to act as plunger and can move independently to back-purge the movable filter. 
     
     
         34 ) The system as recited in  claim 20 , further comprising a recirculation system to reintroduce the reclaimed slurry to the cutting head. 
     
     
         35 ) The system as recited in  claim 20 , further comprising a conditioner system to maintain rheological properties of the fluid. 
     
     
         36 ) The system as recited in  claim 35 , wherein the conditioner system includes a rheological test system. 
     
     
         37 ) The system as recited in  claim 35 , wherein the conditioner system includes a biocide system. 
     
     
         38 ) The system as recited in  claim 20 , wherein the cutting head ejects a jet of slurry surrounded by shielding fluid. 
     
     
         39 ) An abrasive wear control system for regulating movement of abrasive slurry and shielding fluid through a suspension jet cutting head, comprising:
 a) a slurry to shielding fluid volume flow regulator; and   b) a valve system that is operable to provide reverse flow of abrasive slurry through the cutting head to reduce nozzle wear.   
     
     
         40 ) The system as recited in  claim 39 , wherein the slurry to shielding fluid volume flow regulator includes a slurry pressure regulator and a shielding fluid pressure regulator. 
     
     
         41 ) The system as recited in  claim 39 , wherein the slurry to shielding fluid volume flow regulator is a shielding fluid flow control valve. 
     
     
         42 ) The system as recited in  claim 39 , where the valve system includes a slurry valve, and a vent valve. 
     
     
         43 ) The system as recited in  claim 39 , whereby when starting the suspension jet cutting head, the slurry to shielding fluid volume flow regulator establishes a jet of shielding fluid prior to starting the flow of slurry to the cutting head in order to minimize slurry mixing with the shielding fluid when starting slurry flow. 
     
     
         44 ) The system as recited in  claim 39 , whereby when stopping the suspension jet cutting head, the slurry to shielding fluid volume flow regulator stops the flow of slurry to the cutting head, the vent valve is opened temporarily allowing shielding fluid to flow in in reverse from the cutting head and through the slurry valve prior to closing the slurry valve and vent valve in order to minimize nozzle wear during nozzle depressurization. 
     
     
         45 ) A method for reducing abrasive wear of a suspension jet cutting head nozzle, comprising:
 a) providing i) a cutting head with a nozzle, ii) a slurry to shielding fluid volume flow regulator, iii) a slurry valve, and iv) a vent valve;   b) energizing the shielding fluid and slurry; and   c) reversing flow of abrasive slurry through the nozzle while maintaining positive shielding fluid flow during stopping operation to reduce nozzle wear.   
     
     
         46 ) A method for reducing abrasive wear of a suspension jet cutting head nozzle, comprising:
 a) providing i) a cutting head with a nozzle, ii) a slurry to shielding fluid volume flow regulator, iii) a slurry valve, and iv) a vent valve;   b) energizing the shielding fluid and slurry; and   c) starting flow of abrasive slurry only after shielding fluid is flowing through the nozzle.   
     
     
         47 ) A cutting head for abrasive suspension jet cutting using an abrasive slurry and a shielding fluid; comprising:
 a) a feed assembly having a slurry orifice and a shielding fluid orifice;   b) a nozzle having a nozzle entrance orifice, a nozzle exit orifice and a nozzle orifice length therebetween;   c) an acceleration cavity between the slurry orifice and the nozzle entrance orifice, the acceleration cavity narrows from the slurry orifice to the nozzle entrance orifice to provide hydrodynamic focusing within the acceleration cavity; and   d) wherein within the acceleration cavity the abrasive slurry and shielding fluid are accelerated together from the slurry orifice to the nozzle entrance orifice while maintaining a shielding fluid barrier substantially unmixed with abrasive slurry around the abrasive slurry, and wherein both the slurry and shielding fluid pass substantially unmixed through the nozzle.   
     
     
         48 ) The cutting head as recited in  claim 47 , wherein the nozzle orifice has a nozzle orifice diameter, wherein nozzle length is less than the nozzle orifice diameter. 
     
     
         49 ) The cutting head as recited in  claim 47 , the acceleration cavity having a taper angle greater than 15-degrees. 
     
     
         50 ) A system for abrasive suspension jet cutting; comprising:
 a) a feed assembly having a slurry orifice and a shielding fluid orifice;   b) a nozzle;   c) an acceleration cavity between the slurry orifice and the nozzle;   d) abrasive slurry and shielding fluid, wherein the abrasive slurry and shielding fluid have the same flow characteristics; and   e) wherein within the acceleration cavity the abrasive slurry and shielding fluid are accelerated together from the slurry orifice to the nozzle as both pass through the acceleration cavity and exit the orifice.   
     
     
         51 ) The system as recited in  claim 50 , wherein the abrasive slurry and shielding fluid are formed form the same base fluid. 
     
     
         52 ) The system as recited in  claim 50 , wherein the shielding fluid has a flow modifying additive to match the flow characteristics of the shielding fluid to the slurry. 
     
     
         53 ) The system as recited in  claim 52 , wherein the flow modifying additive is at least one from the group consisting of a Xanthan Gum, Guar Gum, Cellulose derivatives, Polyacrylamide, gelatin, bentonite, another natural, another synthetic polymer and clay. 
     
     
         54 ) The system as recited in  claim 51 , wherein the base fluid consists primarily of water and a suspension agent