JPS62500290A - Multi-arc plasma device producing continuous gas jets - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Multi-arc plasma device that produces continuous gas jets This invention is a National Science Foundation With support from the United States Government under Grant No.-<pg82-00628 awarded by It was done. The United States Government has certain rights in this invention.

Background of the invention 1. Field to which the invention belongs The present invention relates to an IC for processing timber by continuous plasma. or at the center of a coalesced plasma column to achieve the desired heat transfer to the granular treated material. Apparatus and method for plasma processing using injected gas .

2 Prior art Thermal plasma formed by the arc between the cathode and anode generates a high @ In recent years, it has attracted the attention of those involved in metallurgy and synthetic chemistry because it has a high degree of activity. are collecting. High intensity arc is @contact, cutting, plasma spray, P@light, high power Used for breaking circuits, melting and alloying, and producing heat-resistant ultrafine particles .

The magnetohydrodynamic effect generated by the arc dominates the high intensity IW arc. is being said. The interaction between the arc current and its own magnetic field produces a pumping effect. jets or gases, called cathode jets and anode jets. cause a flow of gas. The effect of the gas flow induced in this way is The gap between cathode and anode and t& depends on the flow intensity and the anode It greatly affects the total amount of heat transfer to.

The invention uses multiple arc systems in a preferred embodiment. plural In collaboration with the Arc system, J.E.Harry and R.Kn. "Simultaneous operation of electric arcs from the same source" by I. IEEE Trans Plasma Science Sctence) PS, 9 (41PP, 248-254 (1981)) paper, and the 6th l-! Published at the International Plasma Chemistry Symposium Paper “1! Source Design for Multiple Arc Discharge Treatment” [Symposium Proceedings Ndas, Vol. 1. PP, 150-155 (1983)) A known m-air circuit is used.

However, (1) for processing, particles are injected into the plasma region and separated from the anode; in order to allow these particles to be ejected widthwise and outwardly, and (2) multiple cathodes and/or plasmas to limit heating of the anode; Using a torch, it is difficult to form a stable synthetic DC arc so that it can be used There was a problem.

The "plasma torch" used here is a tubular torch with a nozzle at one end. shall mean Ve, which consists of a thin, uniform cathode surrounded by nodes. Ru. When the appropriate power is supplied to the plasma torch, the plasma nozzle is emitted from the aperture.

Problems with heat dissipation on the anode surface also still exist. hot spot cause harmful evaporation of the anode material, localized extremely hot spots (hot spots) It is desirable to avoid the occurrence of In some cases, a liquid-cooled anode is used. Even then, evaporation becomes a problem.

The above-mentioned paper by Bar'J-()farry) states that plasma is formed inside the paper. A number of mantissas spaced apart around a central axis are used to generate an arc. It is written in a8 that you should use a sword, and the se Sayce's U.S. patent f:pj3989512 describes a plasma column. Because of this, they are spaced apart around the central axis. Multiple non-migratable Arcplas Matouchi is written a.

For background on plasma technology, see S, Δ1. L, Hamblyn K [Plasma Technology and its Application to Extractive Metallurgy] nology And Its Application To Extract ive Metallurgy) JC Mineral Science Engineering (Mineral 5science Engineering) SCI.

Engng, Vol, 9JJo, 3, pp, 151-176 (Ju, 1y 1 977)].

Hamblyn's paper, page 153, Figures 6 and 7, A three-phase (AC) plasma system is demonstrated that is stabilized by using a current current source. ing. This device forms a central plasma stream and also generates a uniform plasma. In order to do this, it has been shown to have a central gas along the plasma flow.

This system is mainly used for experimental research on heat transfer to button fever atomized materials in fluidized bed reactors. It was used for research. The equipment of this paper is steam.

The synthetic material used in the device of this invention is tn by three cathodes. There is no preparation for the direct Me arc V, and gas to stabilize the arc Nor does it teach the use of streams and/or the injection and treatment of particulate materials.

A complementary work is a paper by Cbeer et al. [Invited paper: High-intensity reflux Development and application of electric arc (InvitedReview: Developom ent　And　Application　of TheE(igh Inte nsity Convective Electrtcal Arc Chem , Eng, Comm, , Vol. 19. Published in pp. 1-47 (1982). In particular, on pages 17-27, there is a description of the ``cathode'' that occurs near the cathode chip. There is an explanation of ``Dead Pump''. This paper discloses a single cathode and Particles introduced into Zuma are injected into the plasma to some extent, but most of the particles are injected into the plasma. The high-temperature plasma core that moves around Zuma and is useful for processing may not be fully utilized. is taught.

The oil patent that represents the general state of the art in silicon nitride plasma arc expansion. As granted to Harvey et al. on June 3, 1980, the U.S. There is a patent number 4206190. This is a plasma atomization process for forming silicon nitride particles. It shows an arc furnace.

Arc plasma separation of zircon is a chemical engineering l Engineering, November 24. 1975) (Explained in the title paper. This is simply a general application of plasma technology. It's just to show.

Other patents showing the use of plasma arcs and/or plasma generators include: There is one below.

U.S. Patent Number: Date: 3313908 R. Unger ger) et al. April 11, 1967 3496280 D, Du kelow) I mountain 197 (1〃21171/3573090 J, peadar Lin (Paterson) 19711/3s30x3980802 B, 7 -e-) Paton et al. 1976I 9I14 #4121083 R, Smyth 1978 lO/l17I4141694 S, Kamako - (Camacho) 1979 2g2714426709 J, Feger Fegerl et al. 1984#1//171 Multiple cathode plasma generation Although biogens are well known in the prior art, there are several problems as follows.

(1) The plasma column lacks stability, and the plasma column jumps irregularly on the anode surface. It's easy.

(2) Harmful evaporation of the anode due to hot spots localized on the anode surface Let it happen.

(3) Maintain high heat transfer to the anode without creating harmful hot spots. difficult to maintain.

(l↓) When injecting particulate matter into plasma for processing, the viscosity of the plasma difficulty in overcoming thermal and thermal gradient effects.

(5) Leave particulate matter in the plasma for sufficient time to ensure effective and complete treatment. Difficult to maintain.

This invention aims to solve these problems.

Summary of the invention Plasma generation with multiple sources, as indicated by multiple cathode arrangements The plasma generating device includes a plurality of plasma generating members arranged around a central axis. gas nozzle 5 The inert gas or to supply active gas and/or particulate matter.

Its center is located along the axis. For multiple cathode arrangements, the gas nozzle The location of the nozzle is within an area where a plurality of cathodes are arranged, and the nozzle It is directed downward toward the do.

In a preferred embodiment, the multi-arc device has one combined arc. tffff dynamic drive to form two plasma columns, also inert from the nozzle The gas flow improves the stability of the arc and the core of the plasma. In order to provide a means for continuously supplying granular materials and controlling the processing of company principles, oriented along the axis of the plasma column and through the plasma column.

+18 self-d-conducting pumping action produced by the use of an arc generated (11 It is well known that the cathode and anode jets mentioned above exist. , in the device of this invention, the forced direction from the cathode to the anode is Gas flow strongly influences plasma flow. In @1 embodiment of this invention, 1 is mandatory. controlled gas flow to the anode without creating localized hot spots. A bell-like arc with a substantial contact area with the anode to improve heat transfer. This will cause problems.

In addition, the forced gas flow from the central nozzle may cause bath melting and/or chemical reaction of the material. In-flight processes such as reactions are confined within the plasma. As such, it can be used as a means to inject granular material l into the core of an arc with You can do it.

The second embodiment is a forced gas flow and autologous fat that occurs in this type of device. It takes advantage of the interaction between the guiding gas flow and the guiding gas flow.

Arcp2zuma reaction! This invention is used as a &.

The forced gas flow is applied externally to one or both regions of the anode or cathode. It is a convective gas flow given by self-guided gas flow from the cathode to the anode, called cathode jet 2, and from the anode jet 2. It is called a gas pumping effect from the anode to the cathode. be. By utilizing the interaction between these self-induced gas flows and forced gas flows, For example, when producing fine powder from injected granular material, plasma processing The process is improved.

Augmented by cathode jet. Forced gas from cathode to anode The flow suppresses the anode jet and causes a certain position (level) between the cathode and anode ) Can be used to form an IC retention layer. This stagnation area has a high It is a region with a Zuma temperature of W and a relatively small gas flow velocity, and the plasma ideally suited for machining. Conveyed by forced gas flow, as shown later The granular material is carried by high-flying plasma and maintained in a localized area for a relatively long time. Improve the proper formation of processed visual items. Processed granular material.

It is then ejected laterally outward from the arc region and is placed against the side wall of the furnace for collection. Be able to do things. The forced gas can be inert or active with respect to the treatment of granular particles. It can be done.

In both embodiments VC of the invention, the interaction of the self-magnetic fields of the arcs is It works to combine into one arc. This coalescence occurs at a certain distance from the cathode. Since this occurs at the position, the cathode-anode spacing should be set to ensure such a union of 8 fA is adjusted. By properly adjusting the forced gas flow, the rlW reservoir can be at the rear of the coalesced arc, and within the area where the improved material can be processed. I will put it there.

A similar retention effect can also be achieved with a single cathode using a single arc. However, in that case, it is obtained as a result of the aμ cathode; Off-axis [m It does not have the benefit of improved particle transport due to the 11L' peak. aa cathode The device provides improved processing of particles.

pairing a forced gas flow with anode and cathode jets and The interaction of gas flows has shown qualitatively better results and efficiency than previously obtained. Give me.

Brief description of the drawing FIG. 1 is a diagram of a plasma generator of the invention, including a schematically represented electrical circuit. It is a formula diagram.

Figure 2 shows one forced nozzle using a central nozzle to improve heat transfer to the anode. This figure is used to illustrate the type of arc shape (bell shape) obtained by the gas flow. 1 is a schematic side sectional view of the device of the invention; FIG.

Figure 3 shows a plasma column between an anode and a cathode for a plasma reactor. The device of this invention exhibits the effect of forced gas flow slowed to form a stagnation zone in the FIG.

Figure 4 shows forced gas nozzles from the anode and cathode ends of the plasma column. The arrangement in Figure 3 is shown to explain the processing of particles when they are injected through the This is a false cross-sectional view.

Figure 5 shows the operation dominated by the anode jet as shown in Figures 1 and 3. The heat dissipation of the anode in the two arc lengths is shown in Figure 2. The operating mode is dominated by a forced gas flow and a cathode jet. FIG. , of contact of the arc to the anode at different gas flows at a standard current of 100 amperes. It indicates the type.

Figure 6 shows the gas flow at two different arc lengths at standard 100 amps DC. 1 is a graph showing the voltage characteristics of the device of the present invention plotted versus voltage.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In FIG. 1, the plasma forming means is designated generically as lO and is shown in a deaf-like manner. includes an anode 11, and in a generally preferred embodiment includes seven anodes as shown in the figure. supported in a suitable manner (not shown) at the desired spacing from the board. It includes a number of cathodes 12, 13 and 148. These can be cooled appropriately if necessary. For example, a droplet, shown schematically at 20, can be supported in a frame that is It has a visual field and is placed under pressure.

In the configuration shown, the anode 1 is connected to the anode 1 via line 22 and resistor 23. 1. Each cathode 12, 13 and 14 is a line 261 shunt resistor 24 and the power supply 21 via a stabilizing resistor 25 connected directly to the resistor 24. connected to the negative terminal of Cathodes 12, 13 and 14 are connected via line 26 It is connected in parallel to the negative side of 'IIt Momme 21.

The above electrical circuit provides sufficient stability of the 'rlL current to create an arc. . The shunt resistor provides a current measurement means to monitor operation of the device.

In use, the arc is typically a high frequency spark in very close gaps. The cathode is then moved away from the anode.

Anode 11 is preferably a suitable material such as copper or copper.

When used in plasma reactors, annodic The card can be water cooled. However, an anode different from that shown in FIG. The structure also allows for the uncooled molten anode to be held in a crucible. Ru. Also, a coating is placed on the laterally moving substrate, which simultaneously acts as an anode. It is also possible to form a ring.

In a preferred scavenge, the three cathodes 12, 13 and 14 are arranged as shown in FIG. In this case, the angle between the central axis 30 and the vertical axis of the cathode is 45°. They are arranged at an angle of 1200 degrees. Center @1130 is anode 11 passes through the center, and the tips of cathodes 12, 13, and 14 are separated by a predetermined distance. .

A gas nozzle, indicated generally at 32, is centered on the central axis 30 and is located at the cathode. It is located in front of door 13. As shown in FIG. 2, the nozzle 32 has a central opening 31. a suitable inert or active gas through which the plasma formed can be pointed at the core of the

In the embodiment of the invention, cathodes 12, 13 and 14 are A suitable cathode holder or support 34 and cathode tip 338 are included. a A arc is formed between the am cathode and the anode 35. For convenience, the cathode 13 is not shown, but as shown in Figure 1, it can be located at the leading edge of the nozzle. be understood. A plasma column 39 formed by the arc flows from the gas source 37 to the valve. Gas is passed through the central opening 31 of the nozzle 32 at the desired flow rate adjusted by 38. By providing a flow, it is controlled and stabilized.

Valve 38 may be any suitable valve capable of varying the rate of gas flow. As a gas flow, An inert gas such as argon is used to create a core of material whose shape is roughly shown by the dashed line. A portion (core) 40 is formed. Arcs from cathodes 12, 13 and 14 They merge at about 1/3 of the distance from the node to the anode 35, but the exact position is 11. depends on the cathode/anode geometry, capacity and forced gas flow. Ma The shape is like a hanging bell as shown in the figure, where the contact area of the arc has expanded on the 5 anodes. It becomes a shape. The combined arcs form a plasma column 39.

The jet of gas exiting the nozzle 32 tends to stabilize the plasma column 39 and This prevents it from dancing back and forth on the anode 35 when it occurs. Nozzle 32? The gas flow from the anode 35 is often referred to as an anode jet. Obstructing the guided gas flow towards the swords 12, 13 and 14.

From cathodes 12, 13 and 14 to anode 35, called cathode jets It joins the oncoming gas flow and supports it.

In the embodiment shown in FIG. move once. A self-guided anode jet is added to the cathode 12. , 13 and 14 to provide a net positive flow towards the anode 35. .

Applying sufficient gas a from the nozzle 32 along the core 40 of the plasma column 39 As a result, a bell-shaped end 39A of the plasma column 39 is obtained. This gas flow is 1, At that instant, spread along the 350th surface of the anode and forcibly spread the plasma column.

At extremely high temperatures, this would cause excessive evaporation of the anode material. and without forming a contact point of the arc to the localized anode 35. It has the formation of an arc, a wide tail of the plasma column that allows for greater heat transfer. Ras.

Gas flowing from nozzle 32 may be used for simple melting and/or evaporation processes (e.g. be inert for chemical transformations (e.g. reduction, spheroidization, etc.); (e.g. coal gasification).

If necessary, the particles (particulate matter) are removed from the particle source indicated by the reference numeral 41 and from the gas source 37. It can be mixed into the gas supplied from the source. This granular object is thus transformed into a plasma. is injected into the pillar 39, passes downward through the core 40, is mixed with the plasma, and is converted into chemically reacted or heated as desired. Particles enter the gas stream from the particle source @ may be distributed or dispersed in any suitable manner. 1 particle if necessary is processed in the plasma column 39, and the . Deposited as a coating on the material barbs forming the anode 35 or It can be discharged as shown at 42.

Thus, a suitable gas flow can be injected along the axis located between the cathodes. By stabilizing the plasma column and adjusting such gas flow, K, so as to exhibit a bell shape and also give a wide contact area between the plasma and the anode. The plasma column is diffused at the tail in contact with the anode.

In the embodiment of the invention shown in FIG. 2, the plasma column is confined at the anode. The self-guiding gas flow from the anode to the cathode that occurs when gas flow from nozzle 32 augmented by a self-directed gas flow towards the anode from suppressed by The flow from nozzle 32 is between the gas source and nozzle 32 The valve 38 can be adjusted to obtain the desired bell shape.

As shown, the nozzle 32 is water-cooled with a compartment tube 46 surrounding an annular central tube 31. It is a sleeve and is cooled by the water flow along the wall forming the central tube 31.

The water flows away along the outer wall of the nozzle and the nozzle material is degraded by the high environmental equipment of the furnace. prevent it from becoming

If the cathode is replaced by a plasma torch, the plasma torch flow Similar results are seen using a core gas flow for stabilization. Anode 3 5 remains as it is and the plasma jet from the torch is directed to the surface of the anode 35. flowing towards. In this way, the plasma torch is heated after arc start-up. When the anode of Q is electrically blocked, the transferred ) operates in arc mode. The central inert score stabilizes the plasma flow , providing a wide contact area of the plasma to the anode, and reducing processing time and processing temperature changes. improves the ability to control the processing of particles from a particle source.

Figure 3 shows a plasma column morphology that is particularly useful for plasma processing. is the gas I/! passing through valve 38! is obtained by adjusting K. In addition, in Figure 3 Although the cathode 13 is not shown, it is located on the opposite side of the nozzle 32.

As previously mentioned, when there is no gas flow from nozzle 32, there is no gas flow from anode 47. Self-induced gas entrainment occurs , forming an "anode jet" indicated at 52. From anode 47 Similarly to swords 12, 13 and 14, there is an upward (directing ff1i (convection) effect). will. The anode jet becomes more ′& force than the plasma flow, and the anode 4 Plasma extending above the grooves of cathodes 12, 13 and 14 in a direction away from 7 There is something that can be brought about by pouring it on.

However, when the nozzle 32 operates and the gas flow is adjusted to a predetermined level, In this case, the plasma column of this form of the invention, designated by the symbol 5o, is located at the cathode end. It does not extend to the upper blade (1).

In order to use the apparatus of FIG. 3 as a plasma reactor, the anode 47 is Water cooled in a way. In the operating mode VC shown in FIG. The gas flow from nozzle 32 augmented with a cathode jet stream is indicated at 52. This prevents the anode jet from flowing. A stagnation area is formed in the area where the two flows collide. Then, the gas flows into the atmosphere inside the furnace in the direction of the outer VC. This is the cathode 12, 13 and 14 and the anode 47, e.g. A filter plate-like retention area indicated by No. 51 is formed.

The basic phenomenon is that the forced gas flow from nozzle 32 causes cathode jet 60 to In combination with the flow is opposed to the gas flow of the anode jet 52.

Both pressures are radially outward from the equal periphery.

Each of the By adjusting the operating parameters 8, the cathodes 12, 13 and 14 and the anode 47, the retention area 51 can be moved in the axial direction as desired.

The basic means of controlling the position of the retention zone, as used here, is the nozzle It is the adjustment of valve 38 that changes the forced gas flow through 32. This mode of operation In 2, there is a small arc contact area on the anode, 5 producing localized heating. While the self-guided anode jet 52 along the anode surface is supplementally cooled.

This equipment is used as an arc plasma reactor for the chemical treatment of *e) 4, the apparatus shown in FIG. Let's go.

Particulate matter from particle source 41 is introduced into the gas stream within nozzle 32 and forms a plasma column. During the 50's, be transported downwards. At the same time, a small amount of self-induced gas flow at the anode , moving upward as described above. Nozzle lying parallel to the surface of the anode 47 From 56, the auxiliary particles pass from the anode to the cathode in the same anode jet 5. Can be injected into 2.

These auxiliary particles, as shown in FIG. 4 along the self-guided anode jet so that the plasma column 50 is filled with move upwards.

and combined with cathode jet 60 and anode jet 52, In the absence of the stagnation zone 51 generated by the forced gas flow from the nozzle 32 In comparison, for a longer time the particles 54 are treated by the plasma. You will be able to do this.

This process changes the properties of particles, for example to shape irregularly shaped particles into spheres. Do it for the sake of change. Depending on the reaction in the plasma column, auxiliary chemical reactions It is possible to generate a reaction or to break the particles into a fine powder. Sara In addition, the forced gas flow from the nozzle 32 and the spontaneous generation of the plasma column 50 occur. al) The treated particles 54A are transferred to the furnace by using both pumping action. side wall 201c (!II).

This @4 could be used for recovery of treated particles.

The particulate matter is transported to the cathode with the aid of forced gas flow in nozzles 32 and 56. The pumping action of the jet 60 and/or the anode jet 52 generates plasma. Inject into the pillar 50. These pumping actions and forced gas flows To overcome the effects of high temperature gradients and the high viscosity of the plasma, the injection of particles is hindered. Also , v, In a multiple cathode arrangement such as that shown in Figure 4, each cathode The strong plasma produced by the plasma causes particles and particles to be trapped in the area. 2 and then injecting 1 particle into the core of the 2 coalesced plasma. improve input.

Bumping action can also supply particles from both cathode and anode directions. , and allow the processed product to be discharged at half value in the retention area. .

If necessary, a diffused beam of the arc or plasma column can be used, as in the example shown in Figure 2. If there is a bell-shaped attachment, It is possible to significantly increase the passion 51 at the anode. Also, from the nozzle 32 By controlling the forced gas flow of the stagnation zone or disk (plasma evacuation Discs) 8 can be formed at selected locations on the anode.

@5 The trap shows that heat transfer to the anode in the presence of an anode jet is caused by two different Plotted against arc length.

One has a relatively short 5u arc length and the other has a 40 fl arc length.

Using a triple cathode arrangement that provides a flow of 100 amps through each cathode If the arc length is 40 mm, the forced gas flow from the nozzle 32 will be A significant i1 shift or change in heat consumption is observed in the region of 14 g. The arc is spotted from vertical contact (dominated by the anode jet) to bell-shaped contact (forced gas flow and The approximate location where the cathode jet changes to predominance is shown in FIG.

At shorter arc lengths, such as 5th, forced gas from nozzle 32 When the flow changes from 10g/min to 12g IC9.

From the spot contact of the plasma pillar to the anode as shown in Fig. 3, as shown in Fig. 2 It changed into a diffused bell-shaped contact. Furthermore, a reasonable arc length is required. Yes, 1! When the current is 100 amperes, the voltage level is ranging from about 13 volts to about 30 volts for long arc lengths of 40fi. there were. At arc lengths between these two lakes, the voltage will also vary somewhat between these values. do.

Generally speaking, the transition from spot contact to diffuse bell-shaped contact results in heat dissipation This causes a possible change in the amount of gas that the forced gas flow from the nozzle 32 causes each time. This occurred between 10 and 14 g. This is the current and voltage mentioned above. , when a triple cathode is used.

@ As shown in Figure 5, the shorter the arc length, the more the retention area can be adjusted as follows. can. [Flow also has the desired contact point? You can change it so that you don't get caught. .

In Figure 5, the divisions of each curve indicate that heat transfer (heat flow) to the anode is caused by contact with the anode. Begin to increase as area increases.

and diffused bell-shaped contact results in greater heat transfer (heat flow) to the anode. It is shown that.

Figure 6 shows the nozzle vs. voltage to maintain the R of each cathode at 100 amperes. Figure 32 is a graph generally explaining the effect of soil gas flow. this is, For two different arc lengths, at specific currents and in the presence of an anode jet. 5 shows the pressure level of 1 (pressure level) caused by the situation shown in FIG. 8 Diffused bell-shaped contact to the anode in different gas flows as marked This shows the approximate range that forms the .

Experiments have shown that as the current changes, the voltage across the triple cathode changes. Current is 80 amps When ra is increased to the range of Forms a large arc. The cold gas from nozzle 32 soaks into the center of the plasma. It shows a tendency to cool the core of the plasma. However, this is the conductor of the arc. It has almost no effect on the chest of drawers and is 3+! In testing, approximately 80 amps or more Above, the arc voltage remains fairly stable. Additionally, each cathode is nearly identical. draw the same current, especially when a combined arc is present.

In this UA, it was discovered that the longer the arc length, the higher the voltage. It is. a mode of operation in which cathode jets and forced gas flows predominate; That is, the gas flow from the nozzle 32 has a sufficient field to overcome the anode damage. In this case, the optimal operating point where the three arcs are coupled together and the energy consumption is the lowest is , typically at a low voltage point in the range of 80 to 100 amps. This operating mode A diffused bell-shaped contact occurs in the field. If particles are injected, this Particles best enter the core of the hot plasma at the point where the arcs coalesce.

The use of three cathodes increases the stability of the combined arc and reduces particle Create a large volume of plasma to pass through for processing.

The arc voltage generally increases with increasing forced gas flow at each arc length. increase As the gas flow 1 from the nozzle 32 increases, the plasma cooling effect increases. It becomes. Bu2 Sumano cooling increases the resistance of the arc, and the arc voltage increases to compensate. I have to go up to L.

Generally speaking, the tightness of the triple cathode arc is the same as that of the normal single-power sword arc. 181, and the forced gas from the nozzle 32 It behaves like an artificial cold cathode jet, so it is forced The added gas helps stabilize the arc.

occurs prior to the diffuse bell-shaped contact, dominated by the anode jet. In the filtration mode of operation, the flow from the anode to the cathode is A disk of plasma is formed in the retention area 51. In Figure 5, Anor The mode dominated by the dogget is for the arc length A shown there. The diffused hanging contact of the anode appears at low gas Me. It occurs in places where clothing is used so that the maximum amount of heat is consumed for every unit of force.

For some limited values of n, voltage and cathode distance, Figs. The stagnation area 51 shown in FIG. This is caused only by the power jet, but if there is a flow from the nozzle 32, the voltage It is possible to generate a stagnation area in a region where the distance between the current and the cathode is significantly smaller. However, in any case, the occurrence of + It should be noted that

Under typical operating conditions, the forced gas from nozzle 32 is the cathode jet. Approximately 5 times more than Kit's own Ni flow.

The presence of self-guided cathode jet 60 depends, in part, on the shape of the cathode tip. Exists. If the cantilever is not thin and sharp, but round, The cathode jet decreases and the anode jet becomes completely VCf! flowing, a It is possible to operate in node-jet dominated mode with Vc. opposite direction of electron flow The anode jet stream assists in the cation flow.

The combination of forced gas flow and cathode jet creates an anode jet. When the electrons are forced downward toward the anode, the flow becomes dominated by electron flow and the arc You'll have to lower the voltage. The anode jet and the flow in the opposite direction collide with each other. Then, a large voltage drop is required to send 8 # of particles through the retention layer (-).

The anode jet is directed upward along the anode and through the plasma column b “As a result, heat transfer to the anode is hindered.

In this way, from the perspective of heat transfer to the anode, anode jet mode should be avoided. For example, a diffused bell-shaped contact to the anode as shown in Figure @5. Sufficient gas flow should be provided from the cathode side to bring about contact.

However, the light is in anode jet mode and the forced gas from nozzle 32 If the gas flow is selected to form a stagnation zone, the particles can be It has the ability to inject from both central nozzles, and the processing of particles in the plasma retention area is Longer particle treatment times, more heat, and often higher efficacy Erotic.

Directs the gas forced downward at a controlled flow rate along the central axis between the cathodes. One selected strength will provide a warm and stable arc under all conditions. The suppressed gas flow increases the anode heat transfer, and the other (smaller) forced gas flow increases the between the anode and cathode, resulting in renumbered conditions for processing. ffr1 retention area can be generated. Therefore, the operating model shown in FIGS. The flow from the nozzle 32 to achieve the smaller than the generated flow.

Changing the flow is an auxiliary means to control the formation and location of retention zones. Become. At low currents, the strong I of the cathode jet becomes small and the retention area becomes somewhat cathode. Move to the side.

However, as mentioned earlier, the effect of the cathode jet is similar to that of the forced gas flow. It's quite small in comparison.

Pressure of the forced gas nozzle 32 on the cathode side and the forced gas nozzle 56 on the anode side 8. By adjusting IJi, it is possible to adjust the IIL of the retention area.

The carrier gas used to force the particulate material into the arc is an inert gas, or It can exhibit chemical activity depending on the required reaction in the plasma.

This device can be used for physical processing as well as chemical processing. thing Examples of physical treatments include thickening irregularly shaped powder particles, ultrafine powder beds (e.g. This includes the production of silicane and the concentration (furrow ff1) of agglomerates (or rock). Also Chemical treatment includes decomposition of compounds (e.g. toxic waste).

Synthesis of carbides, nitrides and refractory metal oxides, solid% liquid as starting materials or the production of compounds and alloys using gases.

Radial evacuation of the product from the hot plasma region causes rapid cooling of the product. Well, should this be mounted against a water-cooled side wall, or should it be water-cooled? i road The effect is further enhanced by passing the product through it.

The injection nozzle 56 extends radially from the plasma axis, possibly around the axis. About 6 nozzles arranged at equal VC intervals are used. The particles from nozzle 56 are , in a generally known manner, into a gaseous fluid.

This device will work with just one solid cathode, but 3+'[! + cassow The use of a 100% carbon fiber provides more controlled control and action.

This device also has a high level of gas nozzle relative to the cathode tip, multiple arc plugs, Rotation of entire Zuma torch assembly in any direction and rod anode, annular anode Works even with modifications including different anode geometries such as anode or anode crucibles do. In a preferred embodiment of the invention, the injection of particles prevents cathode degradation. This should be done at the same level as or below the cathode tip to ensure maximum stability.

Although this invention has been described with reference to preferred embodiments, those skilled in the art will appreciate that this invention It is recognized that changes in form and details are OT functions without deviating from the above. There will be.

Current 100A anode heat consumption Gas flow (g1 min) current Voltage characteristic curve Waste flow (g/min) National VA sales report

Claims (11)

[Claims] 1. Has a means of forming plasma sulfur toward one surface to form a plasma column An apparatus for plasma processing, wherein the means includes a plurality of plasma processing devices having a center on a central axis. a plasma source having a center on the central axis and a plasma flow from the plasma source A nozzle for gas flow in the same direction and a plasma column formed into the desired shape. and means for regulating the gas flow through said nozzle. Zuma processing equipment. 2. the plasma flow forming means are arranged at substantially equal angles around a central axis; at least three cathodes forming an arc with respect to the anode; Claim 1, wherein the anode constitutes the surface towards which the plasma flow is directed. equipment. 3. The means for forming a plasma stream are arranged at substantially 120° relative to each other about a central axis. Apparatus according to claim 1, comprising three plasma sources arranged at an angle of . 4. said surface is a heat dissipating surface and said means for regulating gas flow is a plasma source. The gas flow in the direction from to the surface becomes the dominant flow inside the plasma flow. and over an area substantially larger than the area of the plasma column above said surface. , wherein the plasma flow is adjusted to spread over the surface. Device. 5. The means for forming the plasma stream generates an arc and directs the plasma flow from the anode to the cathode. an anode having said surface and said surface to generate a self-directed gas flow toward said surface; three cathodes spaced apart from the anode by a predetermined distance; The stage is spaced apart from the face of the anode overcoming self-induced gas flow and is In the arc that is also far away in the direction from the cathode to the anode, a gas flow through a nozzle to form a The device according to item 3 of the scope of demand. 6. The cathode is placed at a distance such that the combined arc forms a single plasma column. , and the nozzle passes through the center of the combined arc. directs the gas flow through the nozzle from the cathode and anode. Plasma located at a distance, radiating from the combined arc, and surrounding the plasma column. and further comprising means for supplying particles to said gas stream. The particles are discharged to the outside around the disk together with the gas supplied from the nozzle. 6. The apparatus according to claim 5. 7. The cathode and anode are positioned, and the gas flow is such that the arc It operates in jet-dominant mode, where there is a flow of gas from the anode to the cathode. The gas flow from the nozzle is adjusted to The plasma discharge disk passes through the plasma column between the electrode and the anode. disk of plasma) and gas supplied through the nozzle. and means for injecting particles into the anode jet stream. Apparatus described in section. 8. Plasma moving along an axis substantially perpendicular to and towards a plane; comprising means for forming a Zuma pillar, directed towards the surface by the next step; How to stabilize the plasma column. (b) injecting a gas stream through the nozzle along said axis and toward said surface; The process of entering. (b) At least one location along the plasma column, where the plasma column is closer to its top end. Depending on the distance between the top of the plasma column and the surface, The process of adjusting the gas flow. 9. Three cathodes are arranged around the axis at an angle with respect to the axis, and the surface Claim 8 includes the step of forming a plasma column by using as an anode. Method described. 10. located between the cathode and the anode, through which gas exits the plasma column. Directing the gas flow towards the cathode to release the stagnation zone that flows radially outward. adjusting the opposing gas flows; The granular objects are placed in the plasma such that the granular objects are processed in the plasma column. injecting particulate matter into the gas stream prior to entering the column; and ejecting the treated particles radially from the plasma column at the height of the retention zone; The method according to claim 9, comprising: 11. Furthermore, the self-induced gas flow formed by the base of the plasma column on said surface injecting particles into the anode substantially parallel to the anode. Method 12 according to item 10. Flows along the plasma column and away from one plane said surface arranged to form an anode jet causing a self-induced gas flow; forming a plasma column moving towards the surface along a substantially perpendicular axis; providing a gas flow along the axis toward the surface and spaced apart from the surface; , forming a stagnation zone through which gas from the plasma column flows radially outward. adjusting the gas flow toward the surface to impede the self-induced gas flow; A method of stabilizing a plasma column directed towards said surface.