Field of Technology
[0001] The technical solution falls within the hydraulics area. The patent subject-matter
is a tool to clean/remove material surfaces and split/clean materials with a liquid
beam enriched with solid abrasive particles.
State of the Art
[0002] At present, an abrasive head is used as a tool with predominantly automatic gas and
abrasive intake to split and cut various materials. The tool consists of three main
components: liquid jet, mixing chamber and abrasive jet. The above-mentioned components
are positioned in line along the tool axis in a way that the high-speed liquid beam
formed by a liquid jet passes all along the tool axis. Water may be used as the liquid
here. Air may be used as the gas. The liquid jet is designed to convert pressure energy
into kinetic energy, thus creating a high-speed liquid beam. The thin liquid beam
passes through the center of the tool or other abrasive head's main parts. The beam
movement in the mixing chamber center may result in automatic gas and abrasive intake
into the mixing chamber. The gas and abrasive particles are accelerated here by the
high-speed liquid beam motion. The created mixture of liquid, gas and abrasive particles
flows on to pass through the abrasive jet center. Further acceleration of the gas
and abrasive particles is made by the action of the high-speed liquid beam flowing
in housing interior of the abrasive jet, which is largely formed by an input cone
linked with the upstream mixing chamber shape and a long cylindrical opening.
[0003] Document
US 2017326706 may appear to be the closest technological state. It describes the jet head dealing
with the gas infeeds to stabilize the water beam. The gas infeeds are implemented
both upstream and downstream the mixing chamber. The gas infeeds are implemented by
several components arranged and inserted in the jet head, while the gas is supplied
upstream, i.e. under an angle of more than 90° to the common axis into the point with
the highest liquid beam velocity, directly under the liquid jet where huge energy
losses of the liquid beam occur. The liquid beam loses its velocity and the vortex
flow may even unbalance the liquid beam. Thus, the solution according to document
US 2017326706 is nearly unusable in practice. Further documents representing general technological
state include for example document
EP 3094448 A,
US 4995202, where liquid is supplied in the jet head in a fully unbalanced manner from the side,
thus losing huge amount of energy and in addition, the gas is supplied upstream the
liquid flow, thus dramatically reducing the liquid beam velocity leading to vortex
flow. Documents
JP S6228173 and
GB 774624 represent general technological state.
[0004] The disadvantage of current solutions such as patents
EP2853349A1 EP0873220B1 as well as
US2016/0129551A1 or PV 2014-754 is that the high-speed liquid beam after the liquid jet creates such
flow field of the entire mixture that allows the abrasive particles to flow up to
the liquid jet itself. Intensive gas backflow is formed around the high-speed beam,
carrying the abrasive particles to the liquid jet body. It's been proved that the
water jet gets worn out by the abrasive particles as they flow in space directly after
the water jet. The described fact shown on Fig.1 results in significant reduction
of the liquid jet's as well as the entire described tool's lifetime. Another resulting
disadvantage is that guaranteeing sufficient tool lifetime requires that the liquid
jet be made of very durable and costly material such as diamond.
Description of the Invention
[0005] A new abrasive head with clean gas infeed to split/cut materials by a liquid beam
enriched with solid abrasive particles was developed. This head significantly extends
the tool lifetime by eliminating damage to the liquid jet's aperture by abrasive as
well as eliminating degradation of abrasive inside the tool.
[0006] The abrasive head fully prevents the gas and abrasive mixture backflow upstream towards
the water jet, making the abrasive particles move downstream outside the tool, thus
eliminating damage to the water jest and degradation of the abrasive itself.
[0007] The backflow avoidance is designed in a manner that the abrasive head contains a
clean gas infeed in the liquid beam infeed channel. The clean gas infeed makes the
gas intake into the abrasive head, thus eliminating unwanted air recirculation along
with the particles of the abrasive itself that harm the tool's internal walls and
mainly the liquid jet's walls. The recirculation is shown on Fig.1 and 2, with Fig.1
describing gas and abrasive upstream recirculation up to the liquid jet in case when
no clean gas infeed is installed, while Fig. 2 shows clean gas flow through the channel
downstream the liquid beam flow which eliminates backward recirculation of gas and
abrasive by filling the entire channel. Thus, clean gas supply into the infeed channels
is made separately before the abrasive infeed.
[0008] From the pressurized water infeed up to the abrasive jet, i.e. downstream, the tool
consists of the liquid jet connected to the infeed channel equipped with the clean
gas intake. The liquid jet leads into the mixing chamber connected to the abrasive
jet. The clean gas infeed has the benefit of being inclined to the common axis by
10 to 90°. At least one gas and abrasive mixture infeed leads into the mixing chamber,
the gas and abrasive mixture has the advantage of being fed into the mixing chamber
through several symmetrically positioned infeeds. The gas and abrasive mixture infeed
has the benefit of being inclined to the common axis by 10 to 90°. The infeeds of
gas and abrasive mixture have the benefit of being connected to the gas and abrasive
mixture distributor.
[0009] The liquid jet, infeed channel, mixing chamber and abrasive jet are positioned in
the tool's axis downstream the pressurized water infeed. The infeed channel's inner
cross-section is smaller than the abrasive jet cylindrical part's inner cross-section,
which guarantees automatic gas and abrasive mixture intake into the abrasive jet.
[0010] The clean gas intake can extend the lifetime of an existing tool. The clean gas infeed
can be implemented in an existing tool in a fairly easy way such as with electro-erosive
machining. Thus, in the case of a new tool, damage to the liquid jet by abrasive particles
is fully avoided, still without any decrease in both the abrasive head's cutting power
as well as energy.
Tool design implementation
[0011] The tool design should be selected with respect to the tool load level. Stressed
tool components, bearing housings and jets may be made of hard metal or high-strength
abrasive-resistant steel (such as 17-4PH, 17022, 1.4057 or 17346 steel etc.) and it's
recommended to select high-strength materials such as diamond or sapphire for the
liquid jets. For connections and unstressed tool parts, it's possible to select less
resistant materials such as PVC.
[0012] It's useful when the tool is made of a bearing housing in which the liquid jet inner
housing is inserted along with other tool components. The pressurized water connection
is located on the top part of the supporting housing. The liquid jet body, the common
channel housing, the inserted jet body and the mixing chamber housing are placed inside
the inner body while the housings and other components may be connected using threaded
joint, press connection or other permanent or demountable means. More housings and/or
components can be made of a single piece. The abrasive jet housing is placed at the
bottom of the supporting housing. As a benefit, the abrasive jet housing can be fixed
in the supporting housing with a threaded joint or can be attached to the supporting
housing via a collet with a nut. The mixing chamber can be a direct part of the bearing
housing.
Summary of presented drawings
[0013]
- Fig 1.
- Technology status. A tool without separate clean gas infeed 96.
- Fig 2.
- A tool with a separate clean air 96 infeed 26.
- Fig 3.
- An abrasive head according to example 1 with a single liquid jet clean gas 96 infeed 26 into infeed channel 25.
- Fig 4.
- An abrasive head according to example 2 with a single liquid jet and inclined clean
gas 96 infeed 26 into the infeed channel 25.
- Fig 5.
- An abrasive head according to example 3 with a single liquid jet, inclined clean gas
96 infeed 26 into the infeed channel 25 and inclined infeed 28 of the gas and abrasive mixture 94.
- Fig 6.
- An abrasive head according to example 4 with a single liquid jet, two inclined clean
gas 96 infeeds 26 into the infeed channel 25 and two inclined infeeds 28 of the gas and abrasive mixture 94.
Examples of Invention Execution
Example 1
[0014] Abrasive head with clean gas infeed into the common channel.
[0015] Fig.3 shows a tool design with clean gas intake
96 through the infeed
26 leading into the infeed channel
25 downstream the water jet
21 located downstream the pressurized liquid infeed
73. The water jet
21 is connected to the infeed channel
25 into which the clean gas
96 infeed
26 leads. The tool main components, i.e. water jet
21, mixing chamber
22 and abrasive jet
23 are positioned in the tool axis
55, while the liquid jet
21 axis
56 is identical with the infeed channel axis
25 and the tool axis
55. The infeed channel
25 leads into the mixing chamber
22 together with one infeed
28 of the gas and abrasive mixture
94. The infeed channel inner cross-section
25 is smaller than the abrasive jet
23 cylindrical part's
75 inner cross-section. This results in the gas and abrasive mixture
94 being intaken the mixing chamber
22 through the infeed
28 of the gas and abrasive mixture
94 automatically, just like the clean gas
96 is automatically intaken through the clean gas
26 infeed
96. The gas and abrasive mixture
94 accelerated by the common high-speed liquid beam
95 enters the abrasive jet
23 connected to the mixing chamber
22. The abrasive jet
23 is positioned in the tool axis
55 at the tool's end. At this point, further acceleration of the described mixture occurs
before impacting on the cut material.
[0016] The abrasive head bearing housing, where liquid jet body
21, mixing chamber housing
22 and abrasive jet body
23 are placed, contains infeed channel
25 downstream the water jet
21, clean gas
96 infeed
26 and the infeed
28 of the gas and abrasive mixture
94. It's made of 17-4PH steel. The mixing chamber housing
22 is made of hard metal. The abrasive jet's housing
23 is made of hard metal. Clean gas
96 infeed
26 made of 17022 steel is connected to the abrasive head's bearing housing. Gas and
abrasive mixture
94 infeed
28 made of 17022 steel is connected to the abrasive head's bearing housing.
[0017] In case of a tool made according to example 1, there is no gas recirculation thanks
to the presence of the clean gas
96 infeed
26 into the infeed channel
25. Thanks to the recirculation avoidance, the abrasive particles don't get near and
don't harm the liquid jet
21 while avoiding their degradation here.
Example 2
[0018] An abrasive head with inclined clean gas infeed into the infeed channel.
[0019] Fig 4 shows a tool design example with clean gas intake
96 through the infeed
26 leading into the common channel
25 under an angle of 55° to the tool axis
55 downstream after the water jet
21 installed after the pressurized liquid infeed
73. The water jet
21 is connected to the infeed channel
25 into which the clean gas
96 infeed
26 leads. The tool main components, i.e. water jet
21, mixing chamber
22 and abrasive jet
23 are positioned in the tool axis
55, while the liquid jet
21 axis
56 is identical with the infeed channel axis
25 and the tool axis
55. The infeed channel
25 leads into the mixing chamber
22 together with one infeed
28 of the gas and abrasive mixture
94. The infeed channel inner cross-section
25 is greater than the abrasive jet
23 cylindrical part's
75 inner cross-section. This results in the gas and abrasive mixture
94 being intaken the mixing chamber
22 through the infeed
28 of the gas and abrasive mixture
94 by overpressure, with the clean gas
96 being automatically intaken through the clean gas
96 infeed
26. The gas and abrasive mixture
94 accelerated by the common high-speed liquid beam
95 enters the abrasive jet
23 connected to the mixing chamber
22. The abrasive jet
23 is positioned in the tool axis
55 at the tool's end. At this point, further acceleration of the described mixture occurs
before impacting on the cut material.
[0020] The abrasive head bearing housing, where liquid jet body
21 and abrasive jet body
23 are placed, contains infeed channel
25 downstream the water jet
21, mixing chamber
22 and the infeed
28 of the gas and abrasive mixture
94. It's made of 1.4057 abrasion-resistant steel. The abrasive jet's housing
23 is made of hard metal. Clean gas
96 infeed
26 made of 17346 steel is connected to the abrasive head's bearing housing. The gas
and abrasive mixture
94 infeed
28 made of 17346 steel is connected to the abrasive head's bearing housing.
[0021] In case of a tool made according to example 2, there is no gas recirculation thanks
to the presence of the clean gas
96 infeed
26 into the infeed channel
25. Thanks to the recirculation avoidance, the abrasive particles don't get near and
don't harm the liquid jet
21 while avoiding their degradation here.
Example 3
[0022] An abrasive head with inclined gas and abrasive mixture infeed and inclined clean
gas infeed.
[0023] Fig.5 shows a tool design example with clean gas intake
96 through the infeed
26 leading into the infeed channel
25 downstream the water jet
21 located downstream the pressurized liquid infeed
73. The water jet
21 is connected to the infeed channel
25 into which the clean gas
96 infeed
26 leads, inclined to the tool axis
55 by 60° downstream. The tool main components, i.e. water jet
21, mixing chamber
22 and abrasive jet
23 are positioned in the tool axis
55, while the liquid jet
21 axis
56 is identical with the infeed channel axis
25 and the tool axis
55. The infeed channel
25 leads into the mixing chamber
22 together with one infeed
28 of the gas and abrasive mixture
94 inclined to the tool axis
55 by 50° downstream. The infeed channel inner cross-section
25 is smaller than the abrasive jet
23 cylindrical part's
75 inner cross-section. This results in the gas and abrasive mixture
94 being intaken into the shaped mixing chamber
22 through the infeed
28 of the gas and abrasive mixture
94 automatically, just like the clean gas
96 is automatically intaken through the clean gas
26 infeed
96. The gas and abrasive mixture
94 accelerated by the common high-speed liquid beam
95 enters the abrasive jet
23 connected to the mixing chamber
22. The abrasive jet
23 is positioned in the tool axis
55 at the tool's end. At this point, further acceleration of the described mixture occurs
before impacting on the cut material.
[0024] The abrasive head bearing housing, where liquid jet body
21, mixing chamber housing
22 and abrasive jet body
23 are placed, contains infeed channel
25 downstream the water jet
21, clean gas
96 infeed
26 and the infeed
28 of the gas and abrasive mixture
94. It's made of 17022 steel. The mixing chamber housing
22 is made of hard metal. The abrasive jet's housing
23 is made of hard metal. The liquid jet
21 is made of sapphire and the infeed channels
25 are made of PVC. Clean gas
96 infeed
26 made of 17022 steel is connected to the abrasive head's bearing housing. Gas and
abrasive mixture
94 infeed
28 made of 17-4PH steel is connected to the abrasive head's bearing housing.
[0025] In case of a tool made according to example 3, there is no gas recirculation thanks
to the presence of the clean gas
96 infeed
26 into the infeed channel
25. Thanks to the recirculation avoidance, the abrasive particles don't get near and
don't harm the liquid jet
21 while avoiding their degradation here.
Example 4
[0026] An abrasive head with two inclined gas and abrasive mixture infeeds and inclined
clean gas infeeds.
[0027] Fig.6 shows a tool design example with clean gas intake
96 through the infeed
26 leading into the infeed channel
25 downstream the water jet
21 located downstream the pressurized liquid infeed
73. The water jet
21 is connected to the infeed channel
25 into which two clean gas
96 infeeds
26 leads, inclined to the tool axis
55 by 60° downstream. The tool main components, i.e. water jet
21, mixing chamber
22 and abrasive jet
23 are positioned in the tool axis
55, while the liquid jet
21 axis
56 is identical with the infeed channel axis
25 and the tool axis
55. The infeed channel
25 leads into the mixing chamber
22 together with two infeeds
28 of the gas and abrasive mixture
94 inclined to the tool axis
55 by 55° downstream. The gas and abrasive
94 mixture infeeds
28 are connected to the distributor of the gas and abrasive mixture
94. The infeed channel inner cross-section
25 is smaller than the abrasive jet
23 cylindrical part's
75 inner cross-section. This results in the gas and abrasive mixture
94 being intaken into the shaped mixing chamber
22 through the infeeds
28 of the gas and abrasive mixture
94 automatically, just like the clean gas
96 is automatically intaken through the clean gas
26 infeed
96. The gas and abrasive mixture
94 accelerated by the common high-speed liquid beam
95 enters the abrasive jet
23 connected to the mixing chamber
22. The abrasive jet
23 is positioned in the tool axis
55 at the tool's end. At this point, further acceleration of the described mixture occurs
before impacting on the cut material.
[0028] The abrasive head bearing housing, where liquid jet body
21, mixing chamber housing
22 and abrasive jet body
23 are placed, contains infeed channel
25 downstream the water jet
21, clean gas
96 infeed
26 and the infeed
28 of the gas and abrasive mixture
94. It's made of 17022 steel. The mixing chamber housing
22 is made of hard metal. The abrasive jet's housing
23 is made of hard metal. The liquid jet
21 is made of sapphire and the infeed channels
25 are made of PVC. Clean gas
96 infeed
26 made of 17022 steel is connected to the abrasive head's bearing housing. Gas and
abrasive mixture
94 infeed
28 made of 17-4PH steel is connected to the abrasive head's bearing housing.
[0029] In case of a tool made according to example 4, there is no gas recirculation thanks
to the presence of the clean gas
96 infeed
26 into the infeed channel
25. Thanks to the recirculation avoidance, the abrasive particles don't get near and
don't harm the liquid jet
21 while avoiding their degradation here.
List reference marks
[0030]
- 21
- - liquid jet
- 22
- - mixing chamber
- 23
- - abrasive jet
- 25
- - infeed channel
- 26
- - clean gas infeeds 96
- 28
- - infeeds of gas and abrasive mixture 94
- 55
- - tool axis
- 56
- - liquid jet axis 21
- 73
- - pressurized liquid infeed
- 75
- - abrasive jet cylindrical section 23
- 94
- - gas and abrasive mixture
- 95
- - liquid beam
- 96
- - clean gas
Applicability in Industry
[0031] Cleaning materials, removing material surfaces, splitting or cutting materials by
liquid beam enriched with abrasive solid particles.