How did the plasma cutting machines work ???

admin

Hi...i need the information about theory and principal of plasma cutting, downloaded books or website. thank you all..Polo Shirt Printing  T shirt Embroidery
Reply:Have you tried a Google search?  Lots of info on the subject can be had by doing so.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:I was looking around for just that info and much is recent and covered by patent.  If  you have access to patent data bases thre would be lots.  Thermal arc has some very good vids as well as info.  The first one I say was in the early 1980's and it was dual gas and a monster.  Even the design of the nozzle and how they get a swirl to the gases varies a great deal.  I have lost count of all the gas combinations that have been tried since it was developed.
Reply:Here is a great place to start.....it is on the Hypertherm website. There are timelines with the history of plasma cutting as well as simplified presntations on how the process works. There are also a couple of white papers (that I wrote many years ago) on the topic of plasma cutting history and high definition plasma.  Use this link to get directly to the info page:http://www.hypertherm.com/en/Informa...asma/index.jspJim Colt
Reply:The plasma cutting process has been around since the late 1950's......however the best technological improvements have been made in the last 15 to 18 years. Hypertherm alone has more than 70 patents related to plasma cutting technology......Jim Colt
Reply:I myself always go to every plasma manufacturers site and readup. Great to see what they all offer up on the creation and future of plasma both in plasma cutting and welding.I first learned from a professor in college but then  got a itch for more I found Hypertherm north of Boston in  Hanover NH. Go to the site Jim pointed you to and you'll find just about everything and anything plasma. What you don't find or might still have questions on  I advise you too contact Jim.(and no I do not work for Hypertherm I am just a very satisfied customer)Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:It's interesting that jeena1 asks,  "How did the plasma cutting machines work ???" As if plasma is over?Sounds like lotechman may be recalling one of the PAK-xx machines.Sounds like jeena1 may be running a little hustle. Sounds like jimcolt knows his plasma.
Reply:Yep lotechman is describing an oldie.I am not sure about a hustle on Jeena's part!!?? It almost sounded like a student asking for information needed possibly for a paper. And no I do not see plasma going away! In fact it is becoming more popular. Two of my friends that own Large Salvage yards here in FL have just replaced over 75% of their cutting equipment with plasma cutters. We also see more folks  here at Welding Web describing how they just purchased plasma cutters as well.As far as Jim Colt of Hypertherm's knowledge of plasma one only has to type his name and do a search of plasma and you'll find him talked about and relied on for his knowledge.Co-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Originally Posted by specter. . .I am not sure about a hustle on Jeena's part!!?? . . .
Reply:Ok I have a question about how plasma works that does not seem to be discussed.  Why is there a swirl or vortex created in the nozzle and what is the effect that makes this important?  I expect it has to do with concentrating the plasma stream but what is that vortex actually doing to concentrate the plasma stream?  And while I am at it .. hafnium... Is that the only electrode material used now and has zirconium been abandoned?
Reply:Ah....the types of questions I love to answer! The gas swirl in the plasma torch is used for 3 distinct reasons:1. By swirling the gas we can control the "anode feet" attachment points of the plasma arc...this controls edge angularity......with a bad edge on the left of the torch and a better edge on the right of the torch. There are some applications with industrial plasma's where we have a clockwise swirl in one torch, and a counterclockwise swirl in another operating on the same gantry for strip cutting or for mirror image cutting.2. In higher technology torches...such as Hypertherm's HyPerformance HPR systems....there is a dual swirl pattern, one to control cut edge angularity, and another swirl rate to provide a centifuge effect that slings cooler plasma gas molecules (heavier) to the outside edge of the nozzle bore to increase noozzle life.3. Gas swirl creates a vortex that controls (magnetically) the arc attachment point on the electrode...which can improve cut edge angularity, but more importantly can dramatically improve elcetrode life. the swirl ring is a critical part in a properly designed plasma torch.Jim Colt
Reply:And you thought it was just a bunch of 'hot air' coming out of the end of plasma torch.Thanks for the detailed explanation Jim.  A lot more to it than one would think.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Originally Posted by jimcoltAh....the types of questions I love to answer! The gas swirl in the plasma torch is used for 3 distinct reasons:1. By swirling the gas we can control the "anode feet" attachment points of the plasma arc...this controls edge angularity......with a bad edge on the left of the torch and a better edge on the right of the torch. There are some applications with industrial plasma's where we have a clockwise swirl in one torch, and a counterclockwise swirl in another operating on the same gantry for strip cutting or for mirror image cutting.2. In higher technology torches...such as Hypertherm's HyPerformance HPR systems....there is a dual swirl pattern, one to control cut edge angularity, and another swirl rate to provide a centifuge effect that slings cooler plasma gas molecules (heavier) to the outside edge of the nozzle bore to increase noozzle life.3. Gas swirl creates a vortex that controls (magnetically) the arc attachment point on the electrode...which can improve cut edge angularity, but more importantly can dramatically improve elcetrode life. the swirl ring is a critical part in a properly designed plasma torch.Jim Colt
Reply:Not so fast Jimmy, now that I have you in my knowledge seeking hands:    I did notice different manufacturers make comments about the kerf being better and worse on alternate sides.  Some have a small little comment buried in the owners manual.    I am wondering since I have seen vortex tubes in action discharging hot gases at one end and cool at the other. Do you know what level of pressure gradient is being used?.  From my understanding an arc travels much more easily in a partial vacuum than it does in high pressure gas.  Does this simple fact concentrate the plasma stream in the center?    Older radial engine ignition systems intended for high altitude would pressurize the conductors and the distributor housing to improve insulation.I found one comment made on one manufacturer's site.  Discharge the arc away from your base metal (causing double arcing)  will lose you ten to fifteen starts on the life of your consumables.also anything about hafnium??TIALast edited by lotechman; 03-12-2009 at 09:45 AM.
Reply:By slinging the cooler gas molecules to the oustide of the already ionized gas stream....we create a boundary layer of cool, un-ionized gas (air) that protects the nozzle bore from the very hot (24,000 F) plasma arc. So think of the cool gas as a thermal insulator that keeps the copper nozzle bore from melting. The vortex principals that you are talking about....I don't know!Hafnium is comparable to zirconium as the electrode emitter when using oxidizing gases (air or oxygen) as the plasma gas. Hafnium is more readily available, is less expensive, and is easier to get a good thermal bond with the copper electrode body....which is necessary to sink the heat away from the hafnium slug to improve its useable life. The hafnium is actually molten during steady state cutting as the arc attachment point creates temperatures in excess of hafniums melting temperature....which is somewhere around 3000 F.Jim