Demand Pulse MIG Welding

Demand Pulse MIG Welder
(courtesy of Aftek-EHS)

Demand Pulse is possible because of the MOSFET, an extremely fast electronic switch. Using constant current DC power, a wire is fed into the arc zone. As the wire approaches the work, the voltage drops as a function of the arc length. At a pre-selected arc voltage (usually 15 volts), the MOSFET fire a pulse of current to expel the tip of the wire across the arc gap. This current is supplied by means of a parallel resistor in the main current control circuit and is generally 100 amps. Switching time is measured in nanoseconds, and the total cycle time is very short, perhaps 15 nanoseconds. An inductor is not required, nor desired, since fast switching is essential. Perfectly tuned, the pulse cycles 200 times per second or slightly less.

The arc looks and sounds like “short-arc”, but a close look will show that there is no short-circuit. The arc length is from .020” to .090”, very short compared to GMAW-P done with conventional machines. This short arc length, combined with the short duration of the pulse, and the low current required to effect transfer gives a total arc “heat” far below that of either short-circuit transfer, or conventional GMAW-P. Fusion is excellent, because the arc never goes “out”.

Below is a demo video using this technology on 18 gauge stainless steel, without any burn through.

For more information contact:

Aftek-EHS

2960 East State Street Ext.
Hamilton, NJ 08619
Phone # 609.588.0900
Fax # 609.588.8333
Email: dap@hotfoilehs.com

Electric Heating Systems for Power Generation Baghouse and Precipitator Hoppers

Pluggage of flyash collection hoppers due to flue condensation is an expensive and unnecessary problem. Type HB Heating Module systems are specifically designed to eliminate the maintenance nightmare of hopper pluggage.

The HB Heating Module system is designed to provide low watt density heat spread over the maximum surface area available for heating. Uniform heating is essential to avoid cold spots, especially near the hopper throat where fly ash pluggage is most prevalent and problematic. To obtain maximum heater coverage, both rectangular and trapezoidal heaters are available to provide the most effective and efficient application of heat.

Most flyash hoppers are designed with poke tubes, manways, and cylindrical throats. As supplemental equipment we can include custom built flexible heating blankets for these problem areas which become integrated with the HB Module system to provide the ultimate in uniform heat distribution.

Electric Heating Systems for Power Industry Baghouse and Precipitator Hoppers from Hotfoil EHS, Inc.

Welcome to Our Industrial Heating, Welding and Weld Pre-heating Blog

Hotfoil-EHS is committed to educating and training users of our products, namely electric hopper heating systems, electric pre and post weld heat treating, heat treating furnaces, and multi-operator welding stations.

In future posts, we hope to provide interesting information for a wide variety of applications, performance, and products for the markets we serve.

Here is a breakdown of those markets and products:

HOTFOIL
Coal and Fly Ash Hopper Heaters, Industrial Tank Heaters, Heating Cable, Silicone Heater Blankets, Control Systems.

EHS
Pre & Post Weld Heat Treating Power Consoles, Ceramic Mat Heaters, TAU Units, Temperature Recorders, Cable Sets, Brinell Testers.

AFTEK-EHS
Multi-Operator Power Supplies, Packaged Welding Systems, Single Operator Welders, GRID Systems, Custom Transformers.