CZ2014754A3

CZ2014754A3 - Tool for cutting by high-speed abrasive liquid jet

Info

Publication number: CZ2014754A3
Application number: CZ2014-754A
Authority: CZ
Inventors: Zdeněk Říha
Original assignee: Ăšstav geoniky AV ÄŚR, v. v. i.
Priority date: 2014-11-05
Filing date: 2014-11-05
Publication date: 2016-05-18
Also published as: WO2016071866A1; EP3215313A1; WO2016071866A4; CZ307832B6

Abstract

Nástroj pro úpravu povrchů a dělení materiálů s hydrodynamickou tryskou generuje abrazivní paprsek, který dokáže velmi efektivně odstraňovat povrchy materiálu nebo dané tělesa materiálů dělit/řezat. Nástroj může sestávat z kapalinové trysky (21), za kterou následuje směšovací komora (22) a abrazivní tryska (23). Skrze směšovací komoru (22) lze přisávat směs plynu a pevných abrazivních částic pomocí přívodu (24) směsi plynu a abrazivních částic. Směs plynu a pevných abrazivních částic je dopravena ze zásobníku pomocí rozváděče (31) a potrubí (35) pro přívod (24) směsi abrazivních částic a plynu. Vysoké účinnost a spolehlivost je dosažena proto, že vnitřní tvar nástroje je navržen tak, aby se vícefázové prostorové proudění blížilo proudění rotačně symetrickému a nedocházelo tak k degradaci abrazivních částic ve směšovací komoře (22) a abrazivní trysce (23) vlivem vzniku zpětného proudění směsi plynu a pevných abrazivních částic.A surface treatment and material cutting tool with a hydrodynamic nozzle generates an abrasive beam that can very effectively remove material or material / material cut surfaces. The tool may consist of a liquid nozzle (21) followed by a mixing chamber (22) and an abrasive nozzle (23). A mixture of gas and solid abrasive particles can be sucked through the mixing chamber (22) via a gas mixture (24) of a mixture of gas and abrasive particles. The mixture of gas and solid abrasive particles is conveyed from the reservoir by means of a distributor (31) and a conduit (35) for supplying (24) a mixture of abrasive particles and gas. High efficiency and reliability is achieved because the internal shape of the tool is designed so that the multiphase spatial flow approaches the rotationally symmetrical flow to avoid degradation of the abrasive particles in the mixing chamber (22) and the abrasive nozzle (23) due to the backflow of the gas mixture and solid abrasive particles.

Description

High Speed Abrasive Fluid Beam Tool

The technical solution is in the field of hydraulics. The subject of the patent is a tool for cleaning / removing material surfaces and cutting / cutting materials with a liquid jet enriched with solid particles of abrasive.

BACKGROUND OF THE INVENTION At present, a high-speed abrasive jet cutting apparatus is used comprising a fluid nozzle of a mixing chamber and an abrasive nozzle. Said components are housed in one support body or in a system of interconnected support bodies. The liquid nozzle produces a high-speed liquid jet, which then flows through the entire tool axis. In the mixing chamber, gas and solid abrasive particles can be sucked through one side opening due to the flow of the high speed jet of liquid. The mixture of gas and abrasive particles can also be conveyed to the mixing chamber under pressure. However, this solution requires additional energy to be supplied. The abrasive and gas particles are further entrained by the liquid jet toward the abrasive nozzle. The abrasive particles are mixed with the gas and liquid jet in the mixing chamber. The mixing chamber is followed by an abrasive nozzle where the abrasive and gas particles are accelerated. The kinetic energy of the liquid jet is passed to the abrasive and gas particles. At the outlet of the abrasive nozzle and actually also from the tool, we get a mixture of gas, liquid and solid abrasive particles with high kinetic energy. The fluid-jet blend then cleans effectively the affected surface or volume of the material. Water is most commonly used as a liquid, and air is most commonly used as a gas.

A disadvantage of existing solutions such as US5144766 US2006 / 0223423A1 and US2014 / 0094093AI is that the flow in the mixing chamber is strongly unsymmetrical and uneven. This is due to the shape of the mixing chamber and one inlet of the air / air mixture. A given type of flow allows abrasive particles to flow freely at the walls of the mixing chamber. The abrasive particles impact the walls of the mixing chamber at relatively high speeds. Thus, they break down into smaller particles (degradation) and deteriorate cutting efficiency.

The current shape of the abrasive fluid jet cutting tool has its axis of rotation on which the liquid nozzle of the mixing chamber and the abrasive nozzle are arranged one behind the other.

I -1- • · · · · · · · · · · · · · · · · · · · Gas and abrasive mixture is fed sideways into the mixing chamber. The liquid nozzle creates a liquid jet. A backflow of the gas mixture and solid abrasive particles occurs in the mixing chamber.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a high speed abrasive fluid jet cutting tool, in other words, a cutting head that includes a mixing chamber geometry that permits flow to be formed without the backflow of the air / abrasive particles, thereby preventing degradation of the abrasive particles.

We have found that the rotationally symmetric geometry of the mixing chamber, where the axis of rotation is formed by the axis of rotation of the tool (or the axis of rotation of the water and abrasive nozzles), creates ideal conditions for the entry of abrasive particles into the mixing chamber. In terms of construction, the clean rotationally symmetrical geometry of the mixing chamber and the entire tool is very difficult to achieve. In this case, the mixing chamber divides the tool into two parts, where a water nozzle is located in one part and an abrasive nozzle in the other. The supply of gas and abrasive then becomes structurally very difficult to solve. However, the rotational symmetry can be significantly approached. We have found a specific tool configuration in which abrasive parts do not collide with each other or with the surrounding walls when a multiphase mixture flows. The abrasive particles are accelerated by the liquid jet in the mixing chamber and the abrasive nozzle without any contact with the walls. Thus, there is no degradation of the abrasive particles. The cutting head according to the invention comprises a plurality of gas and abrasive feeds into the mixing chamber.

The number of gas and abrasive feeds should be at least two and preferably three or more. The more leads we use, the closer we are to the rotationally symmetrical geometry of the mixing chamber and the tool. Another indisputable advantage of this solution is that we significantly reduce the flow rate of gas and solid abrasive particles in their feed lines from the mixing chamber. This reduces the kinetic energy of the abrasive particles and does not degrade them in the feed line and in the mixing chamber. Using three inputs into the mixing chamber instead of one inlet, the kinetic energy of solid abrasive particles decreases up to nine times. In this case, the degradation of the abrasive particles (decomposition of the abrasive particle due to a collision with another abrasive particle or wall) is significantly smaller. In other words, it increases the efficiency of the cutting tool, increases tool life and generates energy savings. The design of the mixing chamber behind the inlet apertures was designed so that there would be no backflow of the gas mixture and the solid abrasive particles at the mixing chamber walls. The flow section of the mixing chamber decreases in the flow direction,

Wherein the flow cross section of each gas and abrasive mixture inlet may preferably be greater than the flow section of the mixing chamber that adjoins them (located downstream of the aforementioned inlets of the liquid jet). The magnitude of the distance between such a mixing chamber cross-section and the mixing chamber cross-section at its end may be at least one inlet diameter of the gas-abrasive mixture inlet.

The size of the outlet section of the mixing chamber should drop to at least half the size of the mixing chamber inlet area, which is determined by the sum of the flow cross sections of the gas mixture mixture and the abrasive chamber.

The flow cross section of each of the gas mixture and abrasive particle feeds should be equal to or greater than the cross section of the mixing chamber heavily behind the gas / abrasive mixture feeds, that is, at the point where the gas / abrasive particle mixture feeds into the mouth mixing chamber.

It is preferred that the entire tool is composed primarily of a support body in which the other parts are mounted as a water jet mixing chamber and an abrasive nozzle. The tool may be assembled with a plurality of support bodies which are preferably connected to each other in a releasable manner. Also, the individual gas and abrasive mixture feeds into the support body.

The construction materials are chosen with respect to the stresses of the individual parts. The tool support body in which the liquid nozzle is located is preferably made of a high strength material, e.g., high strength stainless steel. The mixing chamber is preferably made of hard metal, which is a material resistant to erosion.

As a very advantageous solution, a switchgear is arranged between the tool body and the abrasive reservoir, which distributes the mixture of abrasive parts and gas from one location to the reservoir into several points of the tool body mixture respectively. mixing chamber. There is minimal reduction in the reliability of the entire system (abrasive reservoir - abrasive cutting tool) and minimize the risk of degradation of abrasive particles due to contact with the surrounding walls of the structure. The shape of the switchgear eliminates the risk of degradation of abrasive particles. Essentially, it is a direct-flow device where the gas-abrasive feed mixture from the abrasive reservoir flows into the switchgear, dividing it into a given number of channels with minimal possible directional change.

The switchgear construction material is selected taking into account the presence of abrasive particles. Due to the very low velocities and pressures of the gas / abrasive mixture, it is not necessary to select extremely erosion resistant materials. Standard steel or stainless steel is sufficient for the switchgear body according to the requirements for corrosion resistance. -v • · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

Very durable and rigid materials need only be selected for the liquid nozzle and support body in which the liquid nozzle is mounted. The liquid nozzle was made of 17-4HP in combination with a sapphire screen. The mixing chamber body and the abrasive nozzle should be made of a material resistant to erosion wear such as carbide. Thus, the high speed abrasive fluid jet cutting tool is specific in that the fluid nozzle, mixing chamber, and abrasive nozzle are aligned one with the other in the flow direction, the mixing chamber having a tapered flow direction into which more than one mixture feeds gas and abrasives, wherein the gas mixture and abrasive feeds are centered on each other in the flow axis, wherein the gas and abrasive mixture feed flow cross-sections are larger than the mixing chamber downstream of the gas and abrasive mixture in the flow direction and the mixing chamber outlet flow section is less than the flow section of the mixing chamber downstream of the gas / abrasive mixture. BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1

The current abrasive liquid jet cutting tool shape. The tool has its axis of rotation 59 on which the liquid nozzle 21, the mixing chamber 22 and the abrasive nozzle 23 are arranged one after the other. The gas-abrasive mixture inlet 24 is introduced from the side into the mixing chamber 22. The liquid nozzle 21 forms a fluid jet 60. backflow 61 of a mixture of gas and solid abrasive particles 62 occurs in chamber 22.

FIG. 2

Rotationally symmetrical geometry for abrasive fluid jet cutting. The tool has a rotation axis 59 on which the liquid nozzle 21, the mixing chamber 22 and the abrasive nozzle 23 are arranged one after the other. The gas-abrasive mixture inlet 24 is introduced rotationally by two inlets into the mixing chamber 22. This arrangement permits a contactless trajectory of abrasive particles 63 into the mixing chamber 22 and the abrasive nozzle 23.

FIG. 3. A tool for cutting high-speed liquid jet with four inlets of a mixture of abrasive and gas into a mixing chamber 22 with a conduit 35 for supplying a mixture of abrasive and gas from the distributor 31 described in Example 1. The tool comprises a liquid nozzle 21, mixing

The tool comprises four gas and abrasive mixture feeders 24 to the mixing chamber 22. The gas and abrasive mixture is fed via a line 35 for supplying a mixture of abrasive particles and gas to the mixing chamber 22. The abrasive / gas mixture flowing from the container is divided by a distributor 31 of a mixture of abrasive particles and gas.

FIG. 4 The three-speed high-speed liquid jet cutting tool of the abrasive particle / gas mixture described in Example 2. 4A is a spatial view of the bottom of the tool. 4B is a perspective view of the top of the tool. The tool comprises a liquid nozzle 21, a mixing chamber 22 and an abrasive nozzle 23. The tool comprises three gas and abrasive mixture inlets 24 into a mixing chamber 22. The gas / abrasive mixture is supplied via line 35 to supply a mixture of abrasive particles and gas to the mixing chamber 22. The abrasive / gas mixture flowing from the reservoir is divided into three portions by means of an abrasive particle gas distributor 31 and transported through the abrasive particle / gas mixture outlet 32 to individual lines of conduit 35 for the mixture of abrasive particles and gas.

FIG. 5

Tool shape with four inputs of a mixture of abrasive particles and gas. 5A is a perspective view of the lower portion of the tool described in Example 3. 5B is a perspective view of the top of the tool. The tool includes a liquid nozzle 21, a mixed mixing chamber 22, and an abrasive nozzle 23 with a continuous transition from the mixing chamber 22. The tool comprises four gas and abrasive mixture feeds 24 to the mixing chamber 22. The gas / abrasive mixture is fed via line 35 for the mixture 24 abrasive particles and gas into the mixing chamber 22. The gas / solid abrasive particle mixture flowing from the reservoir is divided into four parts by means of an abrasive particle / gas mixer 31 and transported through a mixture 32 of the abrasive particles / gas mixture into the individual lines of the mixture feed line 35 abrasive particles and gas.

FIG. 6

Tool shape with two inputs of a mixture of abrasive particles and gas. The tool comprises a liquid nozzle 21, a mixing chamber 22 and an abrasive nozzle 23. The tool comprises two gas and abrasive mixture inlets 24 into a mixing chamber 22. The gas / abrasive mixture is fed via a line 35 for supplying a mixture of abrasive particles and gas to the mixing unit. The mixture of gas and solid abrasive particles flowing from the reservoir is divided into two parts by means of an abrasive particle / gas distributor 31 and transported through the outlet 32 of the mixture of abrasive particles and gas to the individual conduit branches 35 for supplying the mixture of abrasive particles and gas. EXAMPLES Example 1 High Speed Abrasive Fluid Jet Cutting Tool with Four Gas and Abrasive Feeds The tool contained four gas and abrasive mixer feeds 24 into a mixing chamber 22. The tool consisted of a fluid nozzle 20, a mixing chamber 22, and an abrasive nozzle 23. In the liquid nozzle 21, due to the tapered diameter, the pressure energy has changed to kinetic energy and a high-speed liquid jet has formed, which has passed through the mixing chamber 22 and the abrasive nozzle 23. The presence of the high-speed liquid jet in the mixing chamber 22 has caused the gas and solid abrasive particles to admix, thereby it was ensured that the particles did not strike the walls of the chamber and did not cause it to wear and did not degrade these particles. A mixture of gas and abrasive particles was introduced into the mixing chamber 22 from the side through the gas and abrasive mixture inlet 24. The gas-abrasive mixture inlet 24 was connected to line 35 for supplying a mixture of abrasive particles and gas 24 to the mixing chamber 22. The abrasive / gas mixture from the container was divided into three parts in the distributor 3! a mixture of abrasive particles and gas and conveyed by means of a mixture of abrasive particles and gas to the conduit 35 for supplying a mixture of abrasive particles and gas to the mixing chamber 22. The gas / abrasive mixture was entrained by the high speed jet of liquid into the abrasive nozzle. and abrasive particles further accelerated by the high speed liquid jet. The entire multiphase mixture emerged from the abrasive nozzle 23 and 23, respectively. tools and hit the surface of the cut material.

Said shape reduces the erosive wear of the mixing chamber 22 by abrasive particles and permits the formation of a flow that approximates the rotationally symmetrical flow. The liquid nozzle was made of 17-4HP in combination with a sapphire screen. The body of the mixing chamber 22 and the abrasive nozzle 23 have been made of hard metal, which is a material resistant to erosion wear. The switchboard 31 was made of 17022 stainless steel. The pipe 35 was made of PVC. The outlet 32 of the mixture and the feed 24 of the mixture of abrasive particles and gas were

The support body, in which the liquid nozzle 21 is mounted, was made of 17024 steel. Example 2 A tool for high speed abrasive liquid jet cutting with three gas and abrasive feeds The tool includes three gas and abrasive mixers 24 for the mixing chamber 22. The tool comprises a fluid nozzle 21, a mixing chamber 22, and an abrasive nozzle 23. In the liquid nozzle 21, the pressure energy is changed to kinetic energy and a high-speed liquid jet is formed, which then passes through the mixing chamber 22 and the abrasive nozzle 23. The presence of the high-speed liquid jet in the mixing chamber 22 causes the mixture of gas and solid abrasive particles to suck. From the side, a mixture of gas and abrasive particles is introduced into the mixing chamber 22 through the gas and abrasive mixture inlet 24. The mixing chamber 22 is shaped so that there is no room for backflow of the gas mixture and solid abrasive particles. Beyond the gas mixture 24 and the abrasive particles, the flow section of the mixing chamber 22 decreases.

Beyond the gas mixture 24 and the abrasive particles, the cross section of the mixing chamber 22 decreases, and the outlet cross section of the mixing chamber 22 is twice less than the cross section of the mixing chamber 22 situated downstream of the inlets 24. chamber 22 just behind the gas mixture 24 and the abrasive particles. The flow velocity of the high-speed liquid jet was approximately 450 m / s in the mixing chamber 22. The gas-abrasive mixture inlet 24 is connected to a line 35 for supplying a mixture of abrasive particles and gas 24 to the mixing chamber 22. The abrasive-gas mixture from the container is divided into three parts in the abrasive-gas mixture distributor 31 and conveyed by an abrasive mixture 32 via an outlet. The gas / abrasive mixture continues together with the high speed jet of liquid towards the abrasive nozzle 23. Here, the gas / abrasive particle mixture is further accelerated by the high speed liquid jet. The entire multiphase mixture then emerges from the abrasive nozzle 23 and 23, respectively. tools and hits the surface of the material being cut. Said shape significantly reduces the erosive wear of the mixing chamber 22 by abrasive particles and permits flow to occur which is very close to the rotationally symmetrical flow. · &Gt; c * • · 9 · · · · · · · * * · Μ · c fc

Very durable and rigid materials must be selected only for the liquid nozzle 21 and the support body in which the liquid nozzle 21 is mounted, for the liquid nozzle 21 a 17-4HP was used, the support body in which the liquid nozzle 21 is mounted was made of steel The body of the mixing chamber 22 and the abrasive nozzle 23 were hardened. Switchgear 31 was made of 17-4PH stainless steel. The pipe 35 was made of polypropylene. The mixture 32 and the mixture 24 of the mixture of abrasive particles and gas were made of PVC. EXAMPLE 3 Tool for High Speed Abrasive Fluid Beam with Four Gas and Abrasive Inlets The tool contained four gas and abrasive mixture inlets 24 into mixing chamber 22. The tool included a fluid nozzle 21, a mixing chamber 22 and an abrasive nozzle 23 in a fluid nozzle 21. there was a change in the pressure energy to kinetic energy and to the formation of a high-speed liquid jet that passed through the mixing chamber 22 and the abrasive nozzle 23. The presence of the high-speed liquid jet in the mixing chamber 22 caused the mixture of gas and solid abrasive particles to suck. From the side, a mixture of gas and solid abrasive particles was introduced into the mixing chamber 22 through the gas and abrasive mixture inlets 24. The mixing chamber 22 has been shaped so that there is no room for backflow of the gas mixture and solid abrasive particles. Beyond the gas mixture 24 and the abrasive particles, the cross section of the mixing chamber 22 decreases, and the outlet cross section of the mixing chamber 22 is three times less than the cross section of the mixing chamber 22 situated downstream of the inlets 24. the mixing chamber 22 heavily behind the inlets 24 of the gas mixture and the abrasive particles. The flow velocity of the high-speed liquid jet was approximately 500 m / s in the mixing chamber 22. The gas-abrasive mixture inlet 24 was connected to line 35 for supplying a mixture of abrasive particles and gas 24 to the mixing chamber 22. The abrasive / gas mixture from the container was divided into four parts in the abrasive-gas mixture distributor 31 and conveyed by a drain 32 mixture of abrasive The gas / abrasive mixture was entrained by the high speed jet of liquid into the abrasive nozzle 23. Here, the gas / abrasive particle mixture was further accelerated by the high speed liquid jet. The shape of the abrasive nozzle 23 downstream of the mixing chamber 22 is adapted to prevent back flow of the gas mixture and solid abrasive particles. Inlet flow section of abrasive nozzle 23 continuously

I • v * · »·

It follows the outlet flow section of the mixing chamber 22. The entire multiphase mixture then emerged from the abrasive nozzle 23 and 23, respectively. tools and fell on the surface of a material that was a granite cube.

Said shape significantly reduced the erosive wear of the mixing chamber 22 and the abrasive nozzle 23 by abrasive particles and allowed the flow to be almost identical to the rotationally symmetrical flow.

The support body in which the liquid nozzle 21 was mounted was made of Inconel steel and the liquid nozzle 21 was made of 17-4HP steel. The body of the mixing chamber 22 and the abrasive nozzle 23 has been preventively made of hard metal, a material resistant to erosion.

Switchgear 31 was made of aluminum alloy ALUMEC. Pipe 35 was made of polyurethane. The mixture 32 and the mixture 24 of the mixture of abrasive particles and gas were made of a bronze alloy. Example 4 Tool for cutting high-speed liquid abrasive jet with two gas and abrasive feeds The tool comprises two gas and abrasive mixer feeds 24 into the mixing chamber 22. The tool consists of a fluid nozzle 21, a mixing chamber 22 and an abrasive nozzle 23 in succession. 21, due to the tapered cross-section, the pressure energy changes to kinetic energy and to a high-speed liquid jet that passes through the mixing chamber 22 and the abrasive nozzle 23. The presence of the high-speed liquid jet in the mixing chamber 22 causes the mixture of gas and solid abrasive particles to suck, thereby ensuring that the particles do not strike the walls of the chamber and do not cause wear and do not degrade these particles. From the side, a mixture of gas and abrasive particles is introduced into the mixing chamber 22 through two inlets 24 of the gas and abrasive mixture. Each gas and abrasive mixture feed 24 is connected to a conduit 35 for supplying a mixture of abrasive particles and gas 24 to the mixing chamber 22. The abrasive / gas mixture from the reservoir is divided into two portions in a mixer 31 of the abrasive particles and gas and conveyed by a mixture outlet 32 abrasive particles and gas into line 35 for supplying a mixture of abrasive particles and gas to mixing chamber 22. The gas / abrasive mixture continues together with the high speed jet of liquid into the abrasive nozzle 23. Here, the gas / abrasive mixture is further accelerated by the high speed liquid jet. Cell

The " multi-phase mixture " then emerges from the abrasive nozzle 23 and 23, respectively. tools and hits the surface of the material being cut.

Said shape reduces the erosive wear of the mixing chamber 22 by abrasive particles and permits the formation of a flow that approximates the rotationally symmetrical flow. Very durable and rigid materials need only be selected for the liquid nozzle 2 and the support body in which the liquid nozzle 21 is mounted. The body of the mixing chamber 22 and the abrasive nozzle 23 have been preventively manufactured from a material resistant to erosion, such as hard metal.

Switchgear 3! it can be made of steel 12050. The pipe 35 can be made of polyethylene. The mixture 32 and the mixture 24 of the mixture of abrasive particles and gas were made of steel 11373. The support body in which the liquid nozzle 2i is mounted was made of 17022 steel.

List of Reference Numbers 21 - Liquid Nozzle 22 - Mixing Chamber 22.4 - Flow Section of Mixing Chamber 22 Behind Supply 24 of Gas and Abrasive Mixture 22.3 - Output Flow Section of Mixing Chamber 22 23 - Abrasive Nozzle 24 - Gas and Abrasive Mixture Supply 31 - Abrasive Particle Mixer and gas 32 - Abrasive particle and gas mixture discharge 35 - Abrasive particle and gas mixture pipe 59 - Rotation axis, Tool axis 60 - Fluid jet 61 - Reverse flow 62 - Gas and solid abrasive particles 63 - Abrasive particle trajectory

Industrial Applicability Cleaning materials, removing material surfaces, cutting or cutting materials with a liquid jet enriched with solid particles of abrasive.

Claims

KY vysok • AT AT AT AT AT AT AT AT AT AT AT 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. 1. an abrasive fluid jet, characterized in that the fluid nozzle (21), the mixing chamber (22) and the abrasive nozzle (23) are aligned with each other in the flow direction, the mixing chamber (22) having a tapering shape in the flow direction to which opens more than one gas / abrasive mixture (24), wherein the gas mixture and abrasive gas inlets (24) are centered on each other in the flow axis, wherein the gas and abrasive mixture inlets (24) are larger than the mixing section (22.4) the chamber (22) downstream of the gas / abrasive mixture inlet (24) and the outlet flow section (22.3) of the mixing chamber (22) is smaller than the flow section (22.4) of the mixing chamber (22) downstream of the inlet (24) gas and abrasives.

High abrasive fluid jet cutting tool according to claim 1, characterized in that three to four gas and abrasive mixture inlets (24) are opened into the mixing chamber (22).

High abrasive fluid jet cutting tool according to claim 1 or 2, characterized in that the abrasive nozzle (23) has a tapered and continuous shape on the mixing chamber (22).

High abrasive fluid jet cutting tool according to claim 1 or 2, characterized in that the flow section (22.4) of the mixing chamber (22) downstream of the inlet (24) is twice the outlet flow cross section (22.3) of the mixing chamber (22).

High abrasive fluid jet cutting tool according to claim 1 or 2, characterized in that the flow cross section of each of the gas / abrasive mixture inlets (24) is the same size as the mixing chamber (22) of the mixing chamber (22). ) a mixture of gas and abrasive particles. ft

High abrasive fluid jet cutting tool according to claim 1, characterized in that it comprises a distributor (31) of a mixture of abrasive particles and gas from which the gas / abrasive mixture feed (24) is branched.