U.S. patent application number 15/524512 was filed with the patent office on 2017-11-23 for wet abrasive blast pot.
This patent application is currently assigned to Graco Fluid Handling (B) Inc.. The applicant listed for this patent is Graco Fluid Handling (B) Inc.. Invention is credited to John McIntyre.
Application Number | 20170334037 15/524512 |
Document ID | / |
Family ID | 55909663 |
Filed Date | 2017-11-23 |
United States Patent
Application |
20170334037 |
Kind Code |
A1 |
McIntyre; John |
November 23, 2017 |
WET ABRASIVE BLAST POT
Abstract
A wet abrasive blast pot includes a cylindrical pressure vessel
have a top section, a bottom section, and sidewalls extending
between the top section and the bottom section. The bottom section
includes an outlet, and the top section includes a fill inlet. The
top section includes a convex head, with the fill inlet located at
the uppermost portion of the pressure vessel.
Inventors: |
McIntyre; John; (Dunnville,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Graco Fluid Handling (B) Inc. |
Minneapolis |
MN |
US |
|
|
Assignee: |
Graco Fluid Handling (B)
Inc.
Minneapolis
MN
|
Family ID: |
55909663 |
Appl. No.: |
15/524512 |
Filed: |
November 2, 2015 |
PCT Filed: |
November 2, 2015 |
PCT NO: |
PCT/US2015/058614 |
371 Date: |
May 4, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62076066 |
Nov 6, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B24C 9/00 20130101; B24C
7/0038 20130101; B24C 7/0007 20130101 |
International
Class: |
B24C 9/00 20060101
B24C009/00; B24C 7/00 20060101 B24C007/00 |
Claims
1. A blast pot for use in wet abrasive blasting systems, the blast
pot comprising: a cylindrical pressure vessel which includes
sidewalls, a bottom section and a top section; wherein the bottom
section includes an outlet; wherein the top section includes a
convex head; and wherein the convex head includes a fill inlet
located at an upper most portion of the pressure vessel.
2. The blast pot claimed in claim 1 wherein the top section further
includes a concave dish top, and wherein a lower most portion of
the concave dish top is connected to the upper most portion of the
convex head at the fill inlet.
3. The blast pot claimed in claim 2 wherein the top section further
includes connecting walls that connect the sidewalls to an outer
most portion of the concave dish top.
4. A blast pot for use in wet abrasive blasting systems, the blast
pot comprising: a cylindrical pressure vessel which includes: a
bottom section; an outlet in the bottom section; a convex head; a
fill inlet located at an upper most portion of the convex head; and
sidewall extending between the bottom section and the convex head;
and a concave dish top mounted on the convex head, wherein a lower
most portion of the concave dish top is connected to the upper most
portion of the convex head at the fill inlet.
5. The blast pot claimed in claim 4 and further comprising:
connecting walls that connect the sidewalls to an outer most
portion of the concave dish top.
Description
BACKGROUND
[0001] Wet abrasive blasting systems are typically used in
situations requiring blasting operations that do not tolerate dry
sandblasting conditions due to environmental or other factors. Wet
abrasive blasting systems are used to control generation of dust
and at the same time ensure that there is minimal damage to the
substrate. Wet abrasive blasting systems force a slurry of abrasive
media into a compressed airstream under controlled conditions. A
blast pot or pressure vessel is charged with water and a solid
abrasive to form a wet abrasive slurry. It is very important that
the blast pot be purged of air prior to commencement of the
blasting operation. The pressurized water forces the slurry out of
the blast pot, into a piping system, and finally into a mixing
point where the wet slurry is mixed with compressed air.
Fluctuations in flow of pressure in either the slurry or
pressurized gas will result in inconsistent behaviour of the wet
abrasive blasting system and ultimately will lead to an
uncontrollable or inefficient blasting process. It has been found
that air entrapment in the blast pot or pressure vessel is a major
contributing factor to instability of wet abrasive blasting
systems. In systems to date, air relief valves have been employed
in order to purge the blast pot or pressure vessel of all air prior
to pressurizing with water. Unfortunately these air bleeding or
purging systems often require two to three minutes of time to
completely evacuate the blast pot or pressure vessel of air thereby
reducing the efficiency of the wet abrasive blasting operation.
[0002] It would be best and beneficial if one were able to utilize
a blast pot pressure vessel design which eliminates the entrapment
of air and therefore reduces or eliminates the need for bleeding of
entrapped air in the pressure vessel prior to commencement of the
blasting operation.
SUMMARY
[0003] A wet abrasive blast pot includes a cylindrical pressure
vessel having a top section, a bottom section, and sidewalls
extending between the top section and the bottom section. The
bottom section includes an outlet, and the top section includes a
fill inlet. The top section includes a convex head, with the fill
inlet located at the uppermost portion of the pressure vessel.
[0004] Preferably, the top section further includes a concave dish
top, wherein a lower most portion of the concave dish top is
connected to the upper most portion of the convex head at the fill
inlet. The top section also preferably includes connecting walls
for connecting the sidewalls to the outer most portion of the
concave dish top.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a cross sectional schematic view of a prior art
blast pot with a concave head configuration.
[0006] FIG. 2 is a schematic cross-sectional view taken through the
middle of a blast pot showing a convex head configuration.
[0007] FIG. 3 is a schematic cross-sectional view taken through the
middle of a blast pot showing a convex head configuration together
with a concave dish extension.
[0008] FIG. 4 is a schematic of a wet abrasive blasting system
including the blast pot of FIG. 3.
DETAILED DESCRIPTION
[0009] FIG. 1 is a prior art depiction of a typically currently
used wet abrasive blast pot 100 which includes the following major
components: pressure vessel 102 having side walls 104, concave top
section 106, bottom section 108, outlet 110, and fill inlet
112.
[0010] Furthermore, pressure vessel 102 defines interior 114 and
also includes pop up valve 116, access port 118 for cleaning out
the pressure vessel, air pressure release valve 120 (which allows
trapped air 124 to be expelled as air 122), and water level 126.
Blast pot 100 further includes legs 130 which support pressure
vessel 102 and dished top section 106 which includes concave head
128.
[0011] In use, prior art blast pot 100 is filled with abrasive and
water through fill inlet 112 until interior 114 of pressure vessel
102 is filled as high as is possible, which normally would be close
to water level 126 shown in FIG. 1. Top section 106 is made up of
dished concave head 128. Due to the geometric configuration of
concave head 128, air 122 is trapped as trapped air 124 in the
space above water level 126 and below concave head 128 as shown in
FIG. 1.
[0012] Due to the location of fill inlet 112, under gravity filling
it is difficult to get the water and abrasive in pressure vessel
102 any higher than water level 126. Once abrasive and water is
filled to water level 126, pop up valve 116 is closed, and then
purging of trapped air 124 is commenced.
[0013] At this point, blast pot 100 is pressurized with pressurized
water. Air release valve 120 allows trapped air 124 to be released
and expelled from interior 114 of pressure vessel 102 as air 122
until such time as water level 126 reaches fill level 132, which is
the upper most point defined where sidewall 104 meet the upper most
portion of concave head 128.
[0014] Blast pot 100 uses an inverted or concave head 128 which
functions not only as a top to pressure vessel 102, but also acts
as a funnel and/or dish hopper for directing the blasting abrasive
material and water into fill inlet 112 of blast pot 100.
[0015] The disadvantage of the prior art design depicted in FIG. 1
is that concave head 128 entraps trapped air 124 above fill inlet
112 of blast pot 100. Therefore blast pot 100 must be fitted with
air release valve 120 to allow trapped air 124 to escape as air
122. This purging or bleeding of trapped air 124 can take upwards
of two to three minutes and result in reduced productivity of the
wet abrasive blasting system.
[0016] FIG. 2 shows blast pot 200, which includes the following
major components: pressure vessel 202 which defines an interior 214
made up of side walls 204, top section 250, bottom section 108
(which includes an outlet 110 at the bottom section 108), and fill
inlet 112 at top section 250. Unlike prior art blast pot 100, blast
pot 200 includes a convex-shaped convex head 252.
[0017] In use, abrasive and water is filled into fill inlet 112.
Due to the configuration of convex head 252 as shown in FIG. 2,
water and abrasive can be filled all the way up to fill level 232
(which is at least the bottom of fill inlet 112), thereby ensuring
that there is little to no entrapped air within pressure vessel 202
once water and abrasive is filled all the way to the top to fill
level 232.
[0018] A disadvantage of this design is that there is no funnel or
dish hopper configuration at the top section 250 which would funnel
water and abrasive into the pressure vessel 202. This could result
in a significant amount of spillage and waste of both the abrasive
material and water.
[0019] FIG. 3 shows blast pot 300, which includes the following
major components: namely, pressure vessel 302, made of side wall
304, bottom section 108 including outlet 110, top section 370
(which includes convex head 252, and connecting wall 362), and
concave dish top 360. Blast pot 300 also includes fill inlet 112,
pop up valve 116, and access port 118.
[0020] In this embodiment, blast pot 300 includes all the
advantages described above for blast pot 200 with the addition of a
concave dish top which connects at fill inlet 112 with convex head
252 and is supported by connecting wall 362. Blast pot 300 does not
entrap any air due to the fact that at fill level 380 most if not
all of the air has been purged from interior 214 of pressure vessel
302 through fill inlet 112, which is at the uppermost point of
pressure vessel 302. Blast pot 300 however also includes the
advantage of the prior art blast pot design 100 section since it
includes a concave dish top 360 which acts as a funnel and/or a
dish hopper for directing abrasive material and water into the fill
inlet of pressure vessel 302.
[0021] FIG. 4 is a schematic diagram of an abrasive wet blasting
system utilizing blast pot 300, which includes the following
additional components not shown in FIG. 3. Water pump 400 (which
preferably is a pneumatic air over water piston pump) takes water
supply 402 and pressurizes it and sends it under pressure to water
inlet 404, thereby pressurizing water abrasive mixture 406 within
interior 214 of pressure vessel 302. Water abrasive mixture 406 is
a slurry which is forced out through outlet 110 and through
transfer hose 410 up through ball valve 412 and through pinch hose
416, which can be shut off with pinch valve 414 prior to water
abrasive mixture 406 entering T connector 418 at mixing point
420.
[0022] Independently, air supply 422 delivers compressed air
(typically from a high volume air compressor) through air valve
424, and check valve 421 to mixing point 420. At mixing point 420,
the compressed air mixes together with the water abrasive mixture
406 and is forced out through blast hose 426 and ultimately through
blast nozzle 428, thus forming an air water abrasive blast 430 out
of blast nozzle 428.
[0023] FIG. 4 shows schematically how the newly conceived of blast
pot 300 would be used together with a typical wet abrasive blasting
system.
[0024] It is also possible that blast pot 200 could be used in a
similar configuration as shown in FIG. 4.
[0025] It should be apparent to persons skilled in the arts that
various modifications and adaptation of this structure described
above are possible without departure from the spirit of the
invention the scope of which defined in the appended claim.
* * * * *