The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Heating Process for Galvanizing Line

2003

Dear Sirs,

I live in Colombia that is a Country located in the Tropic. So we do not use any heating devices during your cold seasons. Today we use electricity to heat our degreasing and our flux. We will be switching to natural gas on next February. In the recent Intergalva we saw that this stages of the process are heated with plastic heat exchangers and most of them using hot water. We are planning to use a gas burner located outside of the tanks, and direct the flame through a in-ox tube that is located inside the tank on the bottom. So this tube will transfer the heat to the solution. Does any one have experience with this kind of heating? Could this affect my process?

Thanks in advance for your help.

Juan Carlos Sanin
Galvanizers - Medellin, Antioquia, Colombia

---

I am not quite sure from your description what your process is, but is very typical to fire a gas burner into a tube for heating. You need to make sure you size the tube properly in regards to diameter and tube length. Carbon steel tubes are sufficient and preferred unless stainless steel is required for corrosion resistance.

Kurt

Kurt Willms
Equipment Manufacturer - Milwaukee, Wisconsin
2003

---

Be careful of corrosion in fire tube heaters in tanks. We had several failures due accelerated corrosion of the hot tube in one of our plants. (316 Stainless tubes) Water inside plastic tubes is far safer. For NaOH degreaser, mild steel is fine though.

Geoff Crowley
Crithwood Ltd.
Westfield, Scotland, UK

2003