Hypertherm: Life Expectancy of Consumables

Cutting Scenarios:

October 2021 - Welding Alloys Manufacturers In India

Hypertherm: Life Expectancy of Consumables

It’s hard to offer an exact (or even an in-exact) estimate of the number of factors that impact the life expectancy of a plasma cutter consumable —operator experience, type and age of the torch, material type and thickness, air quality, etc. However, when the operator understands good piercing and edge-starting techniques which keep molten metal from blowing back onto the torch nozzle (or tip if it is a non-Hypertherm system) then the life of the consumable can be extremely long. Hence, Hypertherm plasma cutter consumables have an edge over conventional plasma cutting machines.

Hypertherm Life Expectancy of Consumables

Cutting Scenarios:

The biggest problem with most plasma cutter torches occurs when hand cutting with exposed (unshielded) nozzle-torch consumables. Ideally, you need to hold a standoff, with an unshielded setup at all amperages greater than 30 amps or so. If the nozzle touches the plate during a cut, it creates an electric current path between the negative electrode, nozzle, and positive plate. This causes a double arc between the electrode and nozzle, and the nozzle and plate, which damages the nozzle’s orifice. When the orifice gets a little damaged, poor angularity is the first thing you’ll notice, followed by more double arcs and more damage. Eventually, you’ll notice slower cut speeds and heavy dross, at which point you’ll likely change your nozzle.

Secondly, some people use a standoff device to hold the torch up off the metal. Unfortunately, molten metal can still blowback during piercing, once again passing electricity from the nozzle to the plate and leading to double arcing. If you have used a handheld torch with an exposed nozzle at more than 30 amps while drag cutting, you’ve likely felt the torch “sticking” to the plate. This is a result of double arcing.

Hypertherm Patented Solutions for Longer Life:

One way around this problem is through the use of shielded torch technology, invented and patented by Hypertherm in the ’80s. The shield works to electrically isolate the nozzle from the plate to totally eliminate double arcing. Hypertherm plasma shielded torches drag cut at up to 200 amps with no friction or double arcing for a dramatic improvement in a plasma cutter consumable’s life and cut quality.

In the last 30 or so years since Hypertherm introduced shielded torch technology, engineers have made enormous strides in extending the life of these consumables. For example, our Duramax torches of Hypertherm plasma systems come with the new standard consumables with nearly all new Powermax systems and as a retrofit torch for older Hypertherm systems and use the shield for just nozzle isolation. The shield and nozzle for these torches use a patented technology called Conical Flow to inject greater airflow around the perimeter of the arc. This increases the energy density of the arc and provides better cooling to the nozzle. This results in no sticking, no double arcing, offering faster-cut speeds, thicker piercing capability, and dramatically longer nozzle life.

So, assuming you are using a Hypertherm plasma Duramax torch with the latest consumable technology, then I would expect you to cut hundreds of feet of metal. In addition, you should be able to make between 600 and 1,200 pieces, after which you would need to replace only your electrode. All your remaining Hypertherm consumables would likely continue to work just fine. Put another way, you should be able to get between 2 and 4 full days of actual arc-on time before needing to replace any of your consumables.

This is why Ador Fontech Limited, the name synonymous with total solutions for any Maintenance & Repair solutions, recommends Hypertherm plasma with Duramax Torch and consumables as a robust cutting solution to all our customers. “Using Spurious/Counterfeit consumables is nothing but a shortcut to machine breakdown & loss of warranty.”

Corrosion and Cracks in Kiln Shells – Repair Solutions from ADFL

Cement Industry uses Rotary Kiln for Pyro-processing the raw mixture of finely crushed limestone (calcium carbonate + silica-bearing minerals) to manufacture cement. Kiln or kiln shell is at the heart of the cement-making process; its capacity, usually defines the capacity of the cement plant.

The Rotary Kiln consists of a tube made up of structural rolled steel material and lined with firebrick (or) castables. This kiln shell/tube slopes (1⁰to 4⁰) from one end to another, and slowly rotates on its axis at between 30 & 250 revolutions per hour depending on the plant. Raw mix is fed in the upper end and the rotation of the kiln causes the mix to move gradually to the other end of the kiln shell. At the other end to the lower part of the kiln, the burner pipe system provides a concentric flame. The raw mix moves under the flame and reaches its peak temperature before it drops out of the kiln into the cooler. In principle, the air drawn through the cooler flows into the kiln causing combustion of the fuel fed through burner pipe ensuring intense heat right across the kiln shell taking the temperature close to 1450⁰ C turning the raw mix into fully calcinated clinker.

Corrosion and Cracks in Kiln Shells

This Kiln shell made of structural rolled steel has a tensile strength between 50,000 to 80,000 PSI at room temperature but once it goes beyond 200 degrees. The tensile strength drops rapidly and at around 430 degrees, studies have noted a strength loss of close to 50% from its original strength.  Because of its continuous working condition at this high temperature along with corrosion caused by castables (which also cause thickness reduction in Rotary kiln or Kiln shell). After a period, fatigue develops in the kiln shell lining and with any small damage to the firebrick or castable it has a temperature attack or thermal shock in the kiln shell causing hot spots and red spots leading to cracks.

Hot Spot & Red Spot

Hot spot is an isolated area in the Rotary kiln where the Kiln shell temperature is close to 550 deg. It is not visible to to the naked eye but can be deducted by Shell scanner, also known as portable Infra-red pyrometer. Red spot is an area visible at night, indicating that the temperature is above 550 degrees. In layman’s terms, hot spot is like a warning sign that action is needed but red spot means immediate action with stoppage of Rotary kiln. Every hot spot eventually becomes a red spot-causing cracks in kiln shell. With today’s improved technology the shell temperature is monitored continuously with computer-aided sensors.  At times kiln is stopped on deduction of a hot spot on further inspection cracks are noticed in the Kiln shell for immediate action

Generally, cracks that are perpendicular to rotary kiln and not of significant lengths and depth are repaired by welding. If the cracks are circumferential in nature, the particular portion is cut and removed & a new shell of the same length is inserted, aligned & welded. Also, kiln shell replacement is the preferred method in most cases of the red spot.

ADFL holds pre-eminence in both these types of repair – kiln shell repairs & kiln shell replacement. Further, we also offer a wear protection solution for high-temperature corrosion

  • We offer customized solutions for the repair of rotary kiln shell cracks with a combination of our LH 1105 & LH 521 alloys. We have credentials in attending a number of these kinds of breakdowns shutdowns
  • We are the only solution provider to offer automated kiln shell joining using the SAW process for kiln shell replacement jobs. By using an automated SAW process, we can complete a single joint in 24-36 hours – offering the highest productivity with X-ray quality welding
  • We also supply kiln shells & cowl shells of the required dimensions. This is a fabricated shell with single SAW joints, making it a value proposition to the industry.
  • We also have a Wear Protection solution for Rotary Kilns against high-temperature corrosion, Zircoat-M, a high-temperature coating, can be applied to a kiln shell’s inside portion before fixing castables to totally eliminate corrosion problems in kilns.

With such customized solutions for cement plant maintenance, repair, and refurbishment requirements, Ador Fontech Limited remains the first name to recall for customers across India, as we stay true to our motto of Life Enhancement of industrial components in every sphere possible.

Reclaim, Do not Replace