Abstract
A suspension medium for improved grit delivery in vapor blast operations sets forth addition of a suspending-agent to a blast solution whereby solids are maintained in suspension absent agitation or mixing for at least 60 hours. The suspending agent increases the viscosity and/or density of the blast solution to increase the buoyancy force and/or acts as a dispersant and/or surfactant to maintain suspension of solids in solution over the extended time period. Different concentrations of suspending-agent may be employed with different grit and solid sized particles, depending on the application of vapor blasting at hand. The suspending-agent is preferably biodegradable.
Claims
1. A suspension medium for improved grit delivery in vapor blast operations comprising: 2% suspending-agent by weight; 98% water by weight; and grit added at a weight ratio of 1 part grit to a range of 1 to 5 parts blast solution.
2. The suspension medium of claim 1 wherein the suspending-agent is a dispersant.
3. The suspension medium of claim 1 wherein the suspending-agent is a surfactant.
4. The suspension medium of claim 1 wherein suspending-agent increases the density of the water and thereby increases the buoyancy force of the suspended grit particles.
5. The suspension medium of claim 1 wherein the suspending-agent is a biodegradable compound.
6. The suspension medium of claim 5 wherein the suspending-agent is xanthan gum.
7. The suspension medium for improved grit delivery in vapor blast operations of claim 1 wherein the grit is added at a weight ratio of 1 part grit to 3 parts blast solution.
8. In an apparatus for wet blasting, a method for improved wet or vapor blast operations comprising addition of a suspending-agent to a blast solution interior to the blast pot wherein settling of grit particles within the blast solution is prevented without the need for agitation of the blast solution as would otherwise be required.
9. The method of claim 8 wherein an amount of the suspending-agent additional to the blast solution comprises between 1 to 3% of the suspending-agent by weight.
10. The method of claim 8 further comprising the step of adding grit to the blast solution at a range of ratios of 1:1 to 1:5 parts grit to water.
11. The method of claim 10 wherein the grit to blast solution ratio is 1 part grit to 3 parts water.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
Figures
[0014] FIG. 1 is a table of various solid particles used with the present invention.
[0015] FIG. 2 is a graph showing the percentage of 10× (20/40) mineral solids (400 to 900 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
[0016] FIG. 3 is a graph showing the percentage of GMA XtremeBlast® mineral solids (Garnet (Fe,Ca).sub.3Al.sub.2(Sio.sub.4).sub.3) (400 to 900 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
[0017] FIG. 4 is a graph showing the percentage of 10× 40/70 mineral solids (200 to 400 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
[0018] FIG. 5 is a graph showing the percentage of Truabrasives® Crushed Glass 40/70 mineral solids (200 to 400 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
[0019] FIG. 6 is a graph showing the percentage of 10× 70/100 mineral solids (100 to 200 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
[0020] FIG. 7 is a graph showing the percentage of Swarco® Glass beads (100 to 200 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
[0021] FIG. 8 is a graph showing the percentage of 10× Powder mineral solids (40 to 70 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
[0022] FIG. 9 is a graph showing the percentage of Vitro Mineral LA500 Glass Powder (10 to 40 μm) in suspension over time in blast solutions having between 0.5 and 2% of the suspending agent added by weight.
DETAILED DESCRIPTION OF THE DRAWINGS
[0023] With reference now to the drawings, and in particular FIGS. 1 through 9 thereof, example of the instant suspension medium for improved grit delivery in vapor blast operations employing the principles and concepts of the present suspension medium for improved grit delivery in vapor blast operations will be described. In each of the Figures shown, the suspending-agent added to the blast solution comprised xanthan gum at between 0.5% to 2.0% by weight. The suspending agent was added to the blast solution and then the like quantity of solid particles was added to each solution at a ratio of 3:1 grit to water by weight.
[0024] After initial agitation, each blast solution sat without agitation or mixing for up to 60 hours. Measurements were made as to the percentage of solid settling out of solution at the following intervals: 1 hour, 2 hours, 12 hours, 24 hours, 36 hours, 38 hours, 48 hours, and 60 hours. It should be noted that, absent any suspending-agent applied at all, it is known that all blast solutions settle 100% solids within one hour.
[0025] FIG. 1 is a table detailing the various solids, of varying sizes, typically used in blast operations for which the present data was compiled. Solids shown range in size from coarse (400 to 900 μm) to micro-fine (10 to 40 μm). Solids are generally mineral solids; garnet (i.e. (Fe, CA).sub.3Al.sub.2(SiO.sub.4).sub.3); and glass oxides, soda lime, or amorphous calcium aluminosilicate glass powder.
[0026] FIG. 2 presents data of suspension times of 10× 20/40, coarse mineral solids (at between 400 to 900 μm) shown in FIG. 1, in various blast solutions having 0.5% suspending-agent added by weight, 1.0% suspending-agent added by weight, 1.5% suspending agent added by weight, and 2.0% suspending-agent added by weight. The Y axis shows percentage of the solid remaining in solution at each of the time intervals shown on the X axis. Note that the time intervals are 1 hour, 2 hours, 12 hours, 24 hours, 36 hours, 38 hours, 48 hours, and 60 hours. The data shows that a blast solution having 2.0% suspending-agent by weight maintains 90% suspension for up to 60 hours, and 100% suspension through at least 38 hours. The blast solution having 1.5% suspending-agent fared almost as well until after 48 hours, after which a rapid decline of suspension was measured to 10% suspension at 60 hours.
[0027] FIG. 3 presents data of GMA XTREMEBLAST®, a garnet coarse solid (400 to 900 μm) in suspension in associated blast solutions over time. Here, blast solutions comprising both 1.5% and 2.0% suspending-agent by weight presented near identical settlement over time, maintaining over 90% suspension through 38 hours, whereafter suspension of solids dropped to 80% at 60 hours. Blast solution having 0.5% suspending-agent lasted up to 2 hours with around 90% particles in suspension, whereafter a rapid settlement was evinced and 0% solids remaining in suspension within 24 hours.
[0028] FIG. 4 presents data of 10× 40/70, medium sized solids (200 to 400 μm) in suspension in associated blast solutions over time. In like manner as evinced above, blast solution having 2.0% suspending-agent by weight maintained 90% or more solids in suspension up to 60 hours. Blast solution with 2.0% suspending-agent maintained 100% suspension until at least 38 hours. Blast solution having 1.5% suspending-agent by weight fared almost as well, showing 80% suspension maintained after 60 hours. Blast solution with 0.5% suspending-agent maintained 100% suspension at least up to 2 hours, and over 80% up to 24 hours.
[0029] FIG. 5 presents data of TRUABRASIVES® Crushed Glass (40/70), medium sized solids (200 to 400 μm), in suspension in associated blast solutions over time. Blast solutions having 1.5% and 2.0% suspending-agent maintaining about 90% suspension over 60 hours. Blast solution having 1.5% suspending agent settled approximately 5% after 12 hours but maintained up to 90% in suspension for the 60 hour period. All blast solutions mateine at least 45% suspension throughout the 60 hour period. Blast solution with 2.0% suspending-agent maintained 100% suspension until at least 38 hours.
[0030] FIG. 6 presents data of 10× 70/100, fine mineral solids (100 to 200 μm) in suspension in associated blast solutions over time. Blast solution with 2.0% suspending-agent maintained 90% suspension of solids over the 60 hour period, with 100% suspension maintained until at least 38 hours. Blast solution with 1.5% suspending-agent maintained 100% suspension for at least 2 hours, with small settlement thereafter, maybe 5% through 38 hours. Suspension dropped to 80% at 60 hours. Blast solution with 1% suspending-agent maintained similar data as the blast solution with 1.5% suspending-agent until 36 hours, whereafter settlement increased, 20% settled by 38 hours and 80% by 48 hours. Blast solution with 0.5% suspending-agent settled 10$ within 2 hours and was 100% settled within 24 hours.
[0031] FIG. 7 presents data of SWARCO® Glass Beads, fine solids (100 to 200 μm), in suspension in associated blast solutions over time. Data show that blast solution having 1.5% suspending-agent performed the best at maintaining suspension of solids at around 90% suspension maintained at 60 hours. However, blast solution having 2.0% suspending-agent maintained 100% suspension at least through 38 hours, whereas blast solution having 1.5% suspending-agent evinced perhaps 5% settlement after 12 hours. Blast solution having 1.0% suspending-agent maintained greater than 50% suspension up to the 60 hour period.
[0032] FIG. 8 presents data of 10× Powder, micro-fine mineral solids (40 to 70 μm), in suspension in associated blast solutions over time. All blast solutions maintained 90% suspension over 60 hours. Blast solution having 2.0% suspendin-agent maintained 100% suspension longest, with settlement or approximately 10% first apparent after 48 hours. All other blast solutions had 10% settlement evident after 12 hours.
[0033] FIG. 9 presents data of VITRO® Mineral LA500 Glass Powder, micro-fine solids (40 to 70 μm), in suspension in associated blast solutions over time. Results are similar to the results shown in FIG. 8. Blast solution having 2.0% suspending-agent maintained 100% suspension for at least 38 hours. All blast solutions maintained 90% suspension at least up to 60 hours.
