Wednesday, August 31, 2016

Industrial Heat Treating: Gas Train Basics

Industrial Heat Treating Burners
Industrial Heat Treating Burners
The item on gas fired heat treating equipment that produces and controls the heat is generally referred to as the “Gas Train.” Its job is to properly and safely mix the fuel / air together and cause combustion.

The combustion provides the thermal energy to heat the workpieces in an oven or furnace to the desired temperature.  The gas train can be broken down into several major components. The major parts of a gas train are:

Blower:

Industrial Heat Treating Gas Train
Industrial Heat Treating Gas Train
The blower introduces and mixes atmospheric air with the available fuel to create combustion. Blowers come in many sizes and velocities to accommodate the combustion required for the work. Common blower sizes are 10HP and 15HP motor and can move up to 2200 cubic feet/minute.

Regulator

Regulates the total volume of fuel available to the burner and available to mix with the combustion air.

Control System

Gas Train Control System
Gas Train Control System
Includes regulating valves and ignition control system. The control system's primary purpose is to control the volume of fuel to the burner, assure that proper gas pressure is available, monitor for the presence of flame, and provide alarms and shutdown in the event of flameout or loss of fuel supply. Safety is paramount for gas trains, so many safety components are designed in the control system. Examples are redundant pilot and main valves, UV sensors, high and low gas pressure switches, power/kill switches, master/slave controllers, warning lights, and purge components to expel gas from the system.

Ignition System and Transformer

Provides the required voltage to create an arc sufficient to light the burner. The ignition system is used to ignite the fuel / air mix - once the ignition takes place, the ignition system is no longer active. Electrical system includes circuit breakers for high and low voltage, starter contactors with over-load, and 750vA transformers for low voltage side.

High Velocity Nozzle Burners

Where the mix of fuel and air combusts and expels a high velocity / high BTU flame as the thermal energy source. Common sizes for burners are 6-10 million BTU, 3-6 million BTU, and 1 million BTU. Features commonly included are separate air and gas connections, UV hook-up, spark ignitors, ample lengths of air and gas hoses.

Watch the video below for a great visual on how a gas train works!


For more information, contact Hotfol-EHS at www.hotfoilehs.com or call 609.588.0900.

Monday, August 29, 2016

New Hotfoil-EHS Catalog Available for Download

Electric Heating Systems, Inc. (EHS), established in 1994 in Robbinsville, NJ, is a designer and supplier of turnkey, permanent low temperature heating systems for the electric power and tank fabricating industries. Later, this division's name was changed to Hotfoil, and the EHS division began manufacturing ceramic mat (pad) heaters, power consoles, and accessories for the heat treating industry.

Hotfoil-EHS is now a major manufacturer and producer of standard and custom designed industrial heat treating products with an exhaustive inventory including custom control panels, heat treating power consoles, cables and splitters, temperature recorders, thermocouple attachment units and pin guns.

Saturday, August 20, 2016

Pre and Post-weld Stress Relief with Induction Heating

pre and post-weld stress relief
Induction heating is used to heat conductive materials. Developed in the early 20th century, it quickly became a popular choice for hardening military equipment parts during wartime. Because of induction heating’s controllability, speed and consistent output, its popularity continued to grow as new manufacturing and production methodologies were developed. Today, induction heating has become a popular technology for the welding industry to provide pre and post-weld stress relief.

Induction heating is unique because it uses molecular excitation as its source of heat, as opposed to open flames or external electric elements. Conduction heaters consist of a few primary components: An electromagnet and an electronic oscillator that passes a high-frequency alternating current (AC) through the electromagnet. RF (radio frequency) energy is transferred into the workpiece via electromagnetic waves. These alternating magnetic waves penetrate the object, creating electric eddy currents. These eddy currents (Foucault currents) flow through the target piece and produce heat. Its important to note that the heat is created from inside the object itself, with no open flame or external electric heat source.

Induction heating works very quickly, and since there is no contact with the target piece, there are far less concerns about part contamination.  Many industrial processes use induction heating when very high temperatures and uniform control is desired.

Pre and post-weld heat treating (stress relieving) is a growing market for induction heating systems because it offers significant benefits such as excellent heat placement and distribution, lower cycle times, safety, ease of use, and efficiency.

Induction heaters provide temperatures and cycle times hard to achieve otherwise. By virtue of their high temperature capabilities, very fast heat up times, precise application of heat, excellent controllability, and ease of setup / breakdown, the use of induction heating has been know to cut 30% to 50% of total weld cycle time in real-life welding applications.

For more information about induction heaters for pre and post-weld heat treating contact:

Hotfoil-EHS, Inc.
2960 East State Street Ext.
Hamilton, NJ 08619
Phone # 609.588.0900
Fax # 609.588.8333
www.hotfoilehs.com