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Title:
A HIGH VELOCITY ABRASIVE FLUID JET CUTTING DEVICE
Document Type and Number:
WIPO Patent Application WO/2016/071866
Kind Code:
A1
Abstract:
The device using a hydrodynamic nozzle for modification of surfaces and material splitting generates an abrasive jet capable of removing material surfaces or splitting/cutting materials with high level of efficiency. The device may consist of the fluid nozzle (21) followed by the mixing chamber (22) and the abrasive nozzle (23). The design of the mixing chamber (22) allows for sucking-in of the gas and solid abrasive particles mixture via the gas and abrasive particles mixture intake (24). The gas and solid abrasive particles mixture is supplied from the reservoir via the distributor (31) and pipeline (35) for abrasive particles and gas mixture intake (24). High efficiency and reliability is achieved by designing the inner shape of the device so that the multi-phase spatial flow was similar to rotation-symmetrical flow to avoid degrading of abrasive particles in the mixing chamber (22) and the abrasive nozzle (23) caused by reverse flow of the gas and solid abrasive particles mixture.

Inventors:
RIHA ZDENEK (CZ)
Application Number:
PCT/IB2015/058558
Publication Date:
May 12, 2016
Filing Date:
November 05, 2015
Export Citation:
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Assignee:
INST OF GEONICS AS CR V V I (CZ)
International Classes:
B24C5/04; B24C1/04
Domestic Patent References:
WO2003018259A22003-03-06
Foreign References:
EP0119338A11984-09-26
DE3516103A11986-11-06
EP1743740A12007-01-17
GB623651A1949-05-20
US4648215A1987-03-10
US5144766A1992-09-08
US20060223423A12006-10-05
US20140094093A12014-04-03
US5643058A1997-07-01
Attorney, Agent or Firm:
PATENT SKY S.R.O. (Prague, CZ)
Download PDF:
Claims:
CLAIMS

1. A high velocity abrasive fluid jet cutting device characterised by the fluid nozzle (21), the intake cross-section (22.4) of the mixing chamber, the mixing chamber (22), the outlet cross-section (22.3) of the mixing chamber (22) and the abrasive nozzle (23) being mutually interconnected on a single axis in the flow direction, while the mixing chamber (22) is of tapered shape in the flow direction, it is delineated by the cross-section (22.4) and the cross-section (22.3); discharged into the cross-section (22.4) are at least two gas and abrasive mixture intakes (24) mutually centred on the flow axis, and the fluid nozzle (21), while the sum of flow cross- sections of the gas and abrasive intakes (24) is greater than the flow cross-section (22.4) of the mixing chamber (22) and the outlet flow cross-section (22.3) of the mixing chamber (22) is smaller than the flow cross-section (22.4) of the mixing chamber (22) and the outlet cross-section (22.3) of the mixing chamber (22) is discharged into the abrasive nozzle (23).

2. The high velocity abrasive fluid jet cutting device as per claim 1 characterised by three to four gas and abrasive mixture intakes (24) being discharged into the cross-section (22.4) of the mixing chamber (22).

3. The high velocity abrasive fluid jet cutting device as per claim 1 or 2 characterised by the abrasive nozzle (23) smoothly following up on the mixing chamber (22) and being tapered in the flow direction.

4. The high velocity abrasive fluid jet cutting device as per claim 1 or 2 characterised by the flow cross-section (22.4) of the mixing chamber (22) being twice as large as the outlet flow cross-section (22.3) of the mixing chamber (22).

5. The high velocity abrasive fluid jet cutting device as per claim 1 or 2 characterised by the flow cross-section of each of the gas and abrasive particles mixture intakes (24) being identical to the cross-section (22.4) of the mixing chamber (22).

6. The high velocity abrasive fluid jet cutting device as per claim 1 or 2 characterised by the flow cross-section of each of the gas and abrasive particles mixture intakes (24) being greater than the cross-section (22.4) of the mixing chamber (22).

7. The high velocity abrasive fluid jet cutting device as per claim 1 or 2 characterised by inclusion of an abrasive particles and gas mixture distributor (31) supplying the gas and abrasive mixture intakes (24).

8. The high velocity abrasive fluid jet cutting device as per claim 7 characterised b y gas and abrasive mixture intakes (24) are distributed into an abrasive particles and gas pipeline system and each of the pipelines (35) is discharged into the abrasive particles and gas mixture outlet (32) discharged into the distributor (31).

Description:
A high velocity abrasive fluid jet cutting device Technical field

The technical solution falls within the area of hydraulics. The subject of the patent is a device for cleaning/removal of surface of materials and splitting/cutting of materials using a fluid jet with added abrasive particles.

State of the Art

A device consisting of a fluid nozzle, a mixing chamber, and an abrasive nozzle is currently used for high velocity abrasive fluid jet cutting. The components are housed in a single body or in an assembly of interconnected bodies. The fluid nozzle creates a high velocity fluid jet which then flows through the central axis of the entire device. Gas and solid abrasive particles may be added in the mixing chamber through a single lateral opening by means of the suction effect created by the flow of the high velocity fluid jet. The mix of gas and abrasive particles may also be added to the mixing chamber under pressure. However, this solution requires additional energy. The gas and abrasive particles are carried by the fluid jet into the abrasive nozzle. Abrasive particles are mixed with gas and the fluid jet in the mixing chamber. The mixing chamber is followed by the abrasive nozzle accelerating the gas and abrasive particles. The kinetic energy of the liquid jet is transmitted to the abrasive particles and gas. Exiting the abrasive nozzle and the device itself is a mixture of gas, fluid and abrasive particles with high kinetic energy. The mixture in the shape of a fluid jet is then highly effective in splitting the surface it hits or the volume of the respective material. Water is the most widely used fluid, while air is the most widely used gas.

A disadvantage of the existing solutions, e.g. patents US5144766 US2006/0223423A1 and US2014/0094093A1, lies in the flow in the mixing chamber being highly asymmetrical and uneven. This is due to the shape of the mixing chamber and the single intake for the air ad abrasive mixture. The type of flow allows abrasive particles to flow freely along the walls of the mixing chamber. Abrasive particles hit the walls of the mixing chamber at relatively high velocities. This causes them to degrade into smaller particles, resulting in reduced cutting efficiency.

The existing shape of the abrasive fluid jet cutting device has a rotation axis along which the fluid nozzle, the mixing chamber and the abrasive nozzle are arranged. The mixture of gas and abrasive is supplied through a side of the mixing chamber. The fluid nozzle creates the fluid jet. Reverse flow of the mixture of gas and abrasive particles is generated in the mixing chamber.

The solution specified in the patent US5643058 describes the possibility to switch between two points of intake of the mixture of gas and abrasive; the intake currently unused for supplying the mixture of gas and abrasive may be closed, or used for measurement of pressure in the mixing chamber during operation of the device, or connected to an air eductor sucking abrasive into the mixing chamber without the high pressure water jet. This is used for cutting brittle materials requiring presence of an abrasive in the high pressure jet already at the time of the first contact with the material being cut. The disadvantage of presence of the second intake for switching between supply of the mixture of gas and abrasive, or connection of another device to the mixing chamber lies in additional expansion of the mixing chamber volume, i.e. unsuitable shape as a space causing reverse flow resulting in further degrading of abrasive particles.

Unlike the previously mentioned patent US5643058, the solution specified in WO 03/018259 describes a minor improvement in the shape of the individual parts being modified so that the entire design of the tool is more compact and easier to assemble.

The device features two intakes for supply of abrasive and air into the mixing chamber. The second intake is present for the purpose of connection of a pressure gauge or eductor for cutting brittle materials. The second intake may even be used for supply of abrasive and air simultaneously with the first intake. Nevertheless, the shape of the mixing chamber is not designed so as to avoid reverse flow of air and abrasive causing further degradation of the abrasive and thus also reduced cutting efficiency.

This is primarily due to the fact that the diameter of the mixing chamber (33) is too large, the design features non-smooth transitions; the mixing chamber (33) is situated between the nozzle body (11) and the supply line (74), forming the space where reverse flow occurs. The diameter of the supply line (74) is too big for the conical orifice (63) and there is no provision for a smooth transition between the mixing chamber (33) and the conical orifice (63) into the abrasive nozzle (49).

Principle of the Invention

The subject of the invention is a high velocity abrasive fluid jet cutting device, or a cutting head, in other words, featuring a mixing chamber geometry allowing for creation of flow without areas of reverse flow of air and abrasive particles, resulting in prevention of degradation of abrasive particles.

We have discovered that the rotation-symmetrical geometry of the mixing chamber with the rotation axis identical to the rotation axis of the device (or the rotation axis of the water and abrasive nozzles, respectively) creates ideal conditions for entry of abrasive particles into the mixing chamber. With regard to the design, purely rotation-symmetrical geometry of the mixing chamber and the entire device is very difficult to achieve. In such a case, the mixing chamber will split the device in two halves, one of them including the water nozzle and the other the abrasive nozzle. Supply of gas and abrasive is then also very difficult from the design perspective. However, it is possible to come very close to rotational symmetry. We have discovered a specific design of the device which avoids abrasive particles hitting each other or the walls in case of flow of a multi-phase mixture. Abrasive particles are accelerated by the fluid jet in the mixing chamber and in the abrasive nozzle without any contact with the walls. This means that degrading of abrasive particles does not occur. The cutting head as per the invention features multiple gas and abrasive intakes into the mixing chamber. There should be at least two, but better three or more gas and abrasive intakes. The more intakes we use, the closer we get to the rotation-symmetrical geometry of the mixing chamber and the entire device. Another indisputable advantage of the solution lies in significantly reduced flow speed of gas and solid abrasive particles in their supply lines to the mixing chamber. This reduces the kinetic energy of fixed abrasive particles, preventing their wear (degrading) in the supply line and at the intake into the mixing chamber. If we use three intakes into the mixing chamber instead of one, the kinetic energy of solid abrasive particles is up to nine times lower. This results in significant reduction of degrading of abrasive particles (decomposition of abrasive particles due to collisions with another particle or the wall). In other words, the above brings higher efficiency of cutting, extended service life of the device and general energy saving. The part of the mixing chamber past the intakes was designed so as to avoid reverse flow of the gas and solid abrasive parts mixture along the walls of the mixing chamber. The flow cross-section of the mixing chamber is decreasing in the flow direction, while the flow cross-section of each intake for the mixture of gas and abrasive may be advantageously greater than the flow cross-section of the mixing chamber that follows up on it (situated past the said intakes in the fluid jet flow direction). The between such cross- section of the mixing chamber and the cross-section of the end section of the mixing chamber may reach at least the size of one diameter of the gas and abrasive mixture intake. The outlet cross-section of the mixing chamber should be reduced at least to a half of the size of the input area of the mixing chamber which is equal to the sum of the cross-sections of the gas and abrasive mixture intakes into the mixing chamber.

The flow cross-section of each of the gas and abrasive particles mixture intake should be identical to or greater than the cross-section of the mixing chamber right past the gas and abrasive particles intakes, i.e. at the point of inlet of gas and abrasive parts mixture supply into the mixing chamber.

It is advantageous if the entire device is made primarily made of a body housing the other components, e.g. the water nozzle, the mixing chamber, and the abrasive nozzle. The tool device may also consist of an assembly of several bodies interconnected in a manner allowing for future disassembly. The individual gas and abrasive mixture intakes are also connected to the body.

The selection of materials takes into consideration the load on the individual components. The main body of the device housing the fluid nozzle should be manufactured of a high-strength material, e.g. high-strength stainless steel. The mixing chamber should be manufactured of cemented carbide, i.e. material resistant to erosive wear.

It appears useful to insert a distributor between the body of the device and the abrasive reservoir for the purpose of distribution of the gas and abrasive particle mixture via a single point from the reservoir to several points of mixture intake of the body of the device, or the mixing chamber, respectively. This results in minimum reduction of reliability of the entire system (abrasive reservoir - abrasive jet cutting tool) and minimum increase of the risk of degrading of abrasive particles due to contact with the walls of the structure. The shape of the distributor eliminates the risk of degrading of abrasive particles. It is indeed a direct flow device where the supplied gas and abrasive parts mixture from the abrasive reservoir flows to the distributor where it is split into the given number of channels with minimum possible change to the flow direction.

Selection of the material of the distributor should take into consideration the presence of abrasive particles. Taking into consideration the very low velocity and pressure of the gas and abrasive particles mixture, extreme erosion resistance of materials is not required. Standard steel or stainless steel is considered adequate for the distributor body depending on requirements for corrosion resistance.

Highly resistant and strong materials must be selected only for the fluid nozzle and the body housing the fluid nozzle. The fluid nozzle was manufactured of 17-4HP combined with a sapphire screen. The body of the mixing chamber and the abrasive nozzle should be made of an erosive wear resistant material, e.g. cemented carbide.

The high velocity abrasive fluid jet cutting device is specific by alignment of the fluid nozzle, the mixing chamber and the abrasive nozzle in a single axis in the flow direction, with the mixing chamber tapered in the flow direction, and with more than one intakes of the gas and abrasive mixture into the chamber; the gas and abrasive mixture intakes are mutually centred in the flow direction, while the flow cross-section of the gas and abrasive mixture intakes is greater than the flow cross-section of the mixing chamber past the gas and abrasive mixture intake in the flow direction and the output flow cross-section of the mixing chamber is smaller than the flow cross-section of the mixing chamber past the gas and abrasive mixture intake.

The high velocity abrasive fluid jet cutting device consists of the fluid nozzle 21, the inlet cross-section 22.4 of the mixing chamber 22, the mixing chamber 22, the outlet cross-section

22.3 of the mixing chamber 22, and the abrasive nozzle 23, all of the above mutually interconnected on a single axis in the flow direction; the mixing chamber 22 is of tapered shape in the flow direction, it is delineated by the cross-section 22.4 and the cross-section 22.3; the fluid nozzle 21 and at least two gas and abrasive mixture intakes 24 mutually centred in the flow direction lead into the cross-section 22.4, while the sum of flow cross-section of the gas and abrasive mixture intakes 24 is greater than the flow cross-section 22.4 of the mixing chamber 22 and the outlet flow cross-section 22.3 of the mixing chamber 22 is smaller than the flow cross-section 22.4 of the mixing chamber 22 and the outlet cross-section 22.3 of the mixing chamber 22 is discharged into the abrasive nozzle 23.

It is advised for the device to include three to four gas and abrasive mixture intakes (24) discharged into the cross-section 22.4 of the mixing chamber 22.

It is also advised to make a smooth transition of the mixing chamber (22) into the abrasive nozzle 23, the nozzle being tapered in the flow direction.

It is advised to make the flow cross-section 22.4 of the mixing chamber 22 twice as large as the outlet flow cross-section 22.3 of the mixing chamber 22 and the flow cross-section of each of the gas and abrasive particles mixture intakes 24 greater or identical to the cross-section

22.4 of the mixing chamber 22.

It is advised for the device to include an abrasive parts and gas mixture distributor 31 providing for split supply to gas and abrasive mixture intakes 24; the gas and abrasive mixture intakes 24 are branched into pipelines 35 for supply of the abrasive particles and gas mixture and each of the pipelines 35 is discharged into an abrasive particles and gas mixture outlet 32 discharged into the distributor 31.

List of pictures in the drawings Fig. 1 State of the art

Currently used shape of the abrasive fluid jet cutting device. The device has the rotation axis 59 along which the fluid nozzle 2J_, the mixing chamber 22 and the abrasive nozzle 23 are arranged. The gas and abrasive mixture intake 24 is connected to the sidewall of the mixing chamber 22. The fluid nozzle 2J_ creates the fluid jet 60. Reverse flow 61 of the mixture of gas and abrasive particles 62 is generated in the mixing chamber 22.

Fig. 2 Rotation-symmetrical geometry of the device

Rotation-symmetrical geometry of the abrasive fluid jet cutting device. The device has the rotation axis 59 along which the fluid nozzle 2J_, the mixing chamber 22 and the abrasive nozzle 23 arranged. The gas and abrasive mixture intake 24 is connected in a rotation- symmetrical manner by means of two inlets into the mixing chamber 22. This configuration allows for contactless trajectory of abrasive particles 63 into the mixing chamber 22 and the abrasive nozzle 23.

Fig. 3 The device as per example No. 1

The high velocity fluid jet cutting device with four abrasive and gas mixture intakes in the mixing chamber 22 with the pipeline 35 for the abrasive and gas mixture intake 24 from the distributor 3J_, described in example No. 1. The device consists of the fluid nozzle 2J_, the mixing chamber 22, and the abrasive nozzle 23. The device features four gas and abrasive mixture intakes 24 into the mixing chamber 22. The gas and abrasive mixture is supplied via the pipeline 35 for the abrasive particles and gas intake 24 into the mixing chamber 22. The abrasive and gas mixture supplied by the reservoir is distributed by the abrasive particles and gas mixture distributor 3 L

Fig. 4 The device as per example No. 2

The high velocity fluid jet cutting device with thee abrasive and gas mixture intakes described in example No. 2. 4A represents a 3D view of the lower part of the device. 4B represents a 3D view of the upper part of the device. The device consists of the fluid nozzle 2J_, the mixing chamber 22, and the abrasive jet 23. The device features three gas and abrasive mixture intakes 24 into the mixing chamber 22. The gas and abrasive mixture is supplied via the pipeline 35 for the abrasive particles and gas mixture intake 24 into the mixing chamber 22. The abrasive and gas mixture flowing from the reservoir is distributed in three parts by the abrasive particles and gas mix distributor 3J_ and transported by the abrasive particles and gas mixture outlet 32 to the individual pipeline branches 35 for the abrasive particles and gas mixture intake 24.

Fig. 5 The device as per example No. 3

The shape of the device with four abrasive particles and gas mixture intakes. 5A represents a 3D view of the lower part of the device described in example No. 3. 5B represents a 3D view of the upper part of the device. The device consists of the fluid nozzle 2J_, the modified mixing chamber 22 and the modified abrasive nozzle 23 with smooth transition from the mixing chamber 22. The device features four gas and abrasive mixture intakes 24 into the mixing chamber 22. The gas and abrasive mixture is supplied via the pipeline 35 for the abrasive particles and gas mixture intake 24 into the mixing chamber 22. The abrasive particles and gas mixture flowing from the reservoir is distributed in four parts by the abrasive particles and gas mixture distributor 3J_ and transported by the abrasive particles and gas mixture outlet 32 to the individual pipeline branches 35 for the abrasive particles and gas mixture intake 24.

Fig. 6 The device as per example No. 4

The shape of the device with two abrasive particles and gas mixture intakes. The device consists of the fluid nozzle 2J_, the mixing chamber 22 and the abrasive nozzle 23. The device features two gas and abrasive mixture intakes 24 into the mixing chamber 22. The gas and abrasive mixture is supplied via the pipeline 35 for the abrasive particles and gas mixture intake 24 into the mixing chamber 22. The gas and abrasive particles mixture flowing from the reservoir is distributed in two parts by the abrasive particles and gas mixture distributor 3J_ and transported by the abrasive particles and gas mixture outlet 32 to the individual pipeline branches 35 for the abrasive particles and gas mixture intake 24. Examples of execution of the invention

Example No. 1

The high velocity abrasive fluid jet cutting device with four gas and abrasive intakes as per Fig. 3.

The device featured four gas and abrasive mixture intakes 24 into the mixing chamber 22. The device consisted of the fluid nozzle 2J_, the mixing chamber 22, and the abrasive nozzle 23, all interconnected. The tapered diameter of the fluid nozzle 2J_ converted pressure energy to kinetic energy and created the high velocity fluid jet flowing through the mixing chamber 22 and the abrasive chamber 23. Presence of high velocity fluid jet in the mixing chamber 22 caused sucking-in of the gas and solid abrasive particles mixture, which ensured that the particles did not hit the chamber walls, thus avoiding wear of the chamber and degrading of the particles. The gas and abrasive particles mixture was supplied to the side of the mixing chamber 22 through the gas and abrasive mixture intake 24. The gas and abrasive mixture intake 24 was connected to the pipeline 35 for the abrasive particles and gas mixture intake 24 into the mixing chamber 22. The abrasive and gas mixture from the reservoir was distributed in three parts by the abrasive particles and gas mixture distributor 3J_ and supplied by abrasive particles and gas mixture outlets 32 to the pipeline 35 for the abrasive particles and gas mixture pipeline intake 24 into the mixing chamber 22. The gas and abrasive mixture was broken away by the high velocity fluid jet and carried into the abrasive nozzle 23 where the gas and abrasive particles mixture was further accelerated by the high velocity fluid jet. The entire multi-phase mixture exited from the abrasive nozzle 23, or the device, respectively, and hit the surface of the material being split.

The above shape design reduces erosive wear of the mixing chamber 22 by abrasive particles and allows for creation of a flow similar to rotation-symmetrical flow.

The fluid nozzle was manufactured of 17-4HP combined with a sapphire screen. The bodies of the mixing chamber 22 and the abrasive nozzle 23 were manufactured of cemented carbide, i.e. a material resistant to erosive wear. The distributor 3J_ was manufactured of 17022 stainless steel. The pipeline 35 was manufactured of PVC. The abrasive particles and gas mixture outlet 32 and intake 24 were manufactured of 17346 steel. The body housing the fluid nozzle 21 was manufactured of 17024 steel. Example No. 2

The high velocity abrasive fluid jet cutting device with three gas and abrasive intakes as per Fig. 4.

The device features three gas and abrasive mixture intakes 24 into the mixing chamber 22. The devices consists of the fluid nozzle 2J_, the mixing chamber 22, and the abrasive nozzle 23, all interconnected. The fluid nozzle 2J_ converts pressure energy to kinetic energy and creates the high velocity fluid jet flowing through the mixing chamber 22 and the abrasive nozzle 23. Presence of high velocity fluid jet in the mixing chamber 22 causes sucking-in of the gas and solid abrasive particles mixture. The gas and abrasive particles mixture is supplied to the side of the mixing chamber 22 through the gas and abrasive mixture intake 24. The mixing chamber 22 is shaped so as to eliminate reverse flow of the gas and solid abrasive particles mixture. Past the gas and abrasive particles mixture intake 24, the flow cross-section of the mixing chamber 22 is reduced.

Past the gas and abrasive particles mixture intake 24, the flow cross-section of the mixing chamber 22 is reduced and the outlet cross-section of the mixing chamber 22 was twice as small as the cross-section of the mixing chamber 22 situated past the intakes 24. The flow cross-section of each of the gas and abrasive particles mixture intakes 24 was identical to the intake cross-section 22.4 of the mixing chamber 22 right past the gas and abrasive particles mixture intakes 24. The flow velocity of the high velocity fluid jet in the mixing chamber 22 was approximately 450 m/s.

The gas and abrasive mixture intake 24 is connected to the pipeline 35 for the abrasive particles and gas intake 24 into the mixing chamber 22. The abrasive and gas mixture from the reservoir was distributed in three parts by the abrasive particles and gas mixture distributor 3J_ and supplied by abrasive particles and gas mixture outlets 32 to the pipeline 35 for the abrasive particles and gas mixture intake 24 into the mixing chamber 22. The gas and abrasive mixture continues together with the high velocity fluid jet to the abrasive nozzle 23 where the gas and abrasive mixture is further accelerated by the high velocity fluid jet. The entire multi-phase mixture then exits from the abrasive nozzle 23, or the device, respectively, and hits the surface of the material being split.

The above shape design significantly reduces erosive wear of the mixing chamber 22 by abrasive particles and allows for creation of a flow highly similar to rotation-symmetrical flow. Highly resistant and strong materials must be selected only for the fluid nozzle 2J_ and the body housing the fluid nozzle 2J_; 17-4HP was used for the fluid nozzle 2J_, while the body housing the fluid nozzle 2J_ was made of 17346 steel. The bodies of the mixing chamber 22 and the abrasive nozzle 23 was manufactured of cemented carbide. The distributor 3J_ was manufactured of 17-4PH stainless steel. The pipeline 35 was manufactured of polypropylene. The abrasive particles and gas mixture outlet 32 and intake 24 were manufactured of PVC.

Example No. 3

The high velocity abrasive fluid jet cutting device with four gas and abrasive intakes as per Fig. 5.

The device featured four gas and abrasive mixture intakes 24 into the mixing chamber 22. The devices consisted of the fluid nozzle 2J_, the mixing chamber 22, and the abrasive nozzle 23, all interconnected. The fluid nozzle 2J_ converted pressure energy to kinetic energy and created the high velocity fluid jet flowing through the mixing chamber 22 and the abrasive nozzle 23. Presence of high velocity fluid jet in the mixing chamber 22 caused sucking-in of the gas and solid abrasive particles mixture. The gas and solid abrasive particles mixture was supplied to the side of the mixing chamber 22 through the gas and abrasive mixture intakes 24. The mixing chamber 22 was shaped so as to eliminate reverse flow of the gas and solid abrasive particles mixture. Past the gas and abrasive particles mixture intake 24, the flow cross-section of the mixing chamber 22 is reduced and the outlet cross-section of the mixing chamber 22 was three times as small as the cross-section of the mixing chamber 22 situated past the intakes 24. The flow cross-section of each of the gas and abrasive particles mixture intakes 24 was identical to the cross-section 22.4 of the mixing chamber 22 right past the gas and abrasive particles mixture intakes 24. The flow velocity of the high velocity fluid jet in the mixing chamber 22 was approximately 500 m/s.

The gas and abrasive mixture intake 24 was connected to the pipeline 35 for the abrasive particles and gas intake 24 into the mixing chamber 22. The abrasive and gas mixture from the reservoir was distributed in four parts by the abrasive particles and gas mixture distributor 31 and supplied by abrasive particles and gas mixture outlets 32 to the pipeline 35 for the abrasive particles and gas mixture intake 24 into the mixing chamber 22. The gas and abrasive mixture was broken away by the high velocity fluid jet and carried into the abrasive nozzle 23 where the gas and abrasive particles mixture was further accelerated by the high velocity fluid jet. The shape of the abrasive nozzle 23 past the mixing chamber 22 is modified so as to avoid reverse flow of the gas and solid abrasive particles mixture. The intake flow cross-section of the abrasive nozzle 23 smoothly transited from the outlet flow cross-section 22.3 of the mixing chamber 22. The entire multi-phase mixture then exited from the abrasive nozzle 23, or the device, respectively, and hit the surface of the material being split, a granite cube.

The above shape design significantly reduced erosive wear of the mixing chamber 22 and the abrasive nozzle 23 by abrasive particles, allowing for creation of a flow almost identical to rotation-symmetrical flow.

The body housing the fluid nozzle 2J_ was manufactured of Inconel steel and the fluid nozzle 21 was manufactured of 17-4HP steel.

The bodies of the mixing chamber 22 and the abrasive nozzle 23 was preventively manufactured of cemented carbide, a material resistant to erosive wear.

The distributor 3J_ was manufactured of ALUMEC aluminium alloy. The pipeline 35 was manufactured of polyurethane. The abrasive particles and gas mixture outlet 32 and intake 24 were manufactured of bronze alloy.

Example No. 4

The high velocity abrasive fluid jet cutting device with two gas and abrasive intakes as per Fig. 5

The device features two gas and abrasive intakes 24 into the mixing chamber 22. The device consists of the fluid nozzle 2J_, the mixing chamber 22, and the abrasive nozzle 23, all interconnected. The tapered diameter of the fluid nozzle 2J_ converts pressure energy to kinetic energy and creates the high velocity fluid jet flowing through the mixing chamber 22 and the abrasive nozzle 23. Presence of high velocity fluid jet in the mixing chamber 22 causes sucking-in of the gas and solid abrasive particles mixture, which ensures that the particles do not hit the chamber walls, thus avoiding wear of the chamber and degrading of the particles. The gas and abrasive particles mixture is supplied to the side of the mixing chamber 22 through the two gas and abrasive mixture intakes 24. Each of the gas and abrasive mixture intakes 24 is connected to the pipeline 35 for the abrasive particles and gas mixture intake 24 into the mixing chamber 22. The abrasive and gas mixture from the reservoir is distributed in two parts by the abrasive particles and gas mixture distributor 3J_ and supplied by abrasive particles and gas mixture outlets 32 to the pipeline 35 for the abrasive particles and gas mixture pipeline intake 24 into the mixing chamber 22. The gas and abrasive mixture continues together with the high velocity fluid jet into the abrasive nozzle 23 where the gas and abrasive particles mixture is further accelerated by the high velocity fluid jet. The entire multi-phase mixture then exits from the abrasive nozzle 23, or the device, respectively, and hits the surface of the material being split.

The above shape design reduces erosive wear of the mixing chamber 22 by abrasive particles and allows for creation of a flow similar to rotation-symmetrical flow.

Highly resistant and strong materials must be selected only for the fluid nozzle 2J_ and the body housing the fluid nozzle 2J_. The bodies of the mixing chamber 22 and the abrasive nozzle 23 was preventively manufacture of a material resistant to erosive wear, e.g. cemented carbide.

The distributor 3J_ may be manufactured of 12050 steel. The pipeline 35 may be manufactured of polyethylene. The abrasive particles and gas mixture outlet 32 and intake 24 were manufactured of 11373 steel. The body housing the fluid nozzle 2J_ was manufactured of 17022 steel.

List of reference numerals

21 - fluid nozzle

22 - mixing chamber

22.4 - intake flow cross-section of the mixing chamber 22

22.3 - outlet flow cross-section of the mixing chamber 22

23 - abrasive nozzle

24 - gas and abrasive mixture intake

31 - abrasive particles and gas mixture distributor

32 - abrasive particles and gas mixture outlet

35 - pipeline supplying the abrasive particles and gas mixture

59 - rotation axis, device axis

60 - fluid jet

61 - reverse flow

62 - gas and solid abrasive particles mixture

63 - abrasive particles trajectory Industrial applicability

Cleaning of materials, removal of material surface, splitting or cutting of materials fluid jet with added solid abrasive particles.