Backpass

Are you reffering to "backpass" of a weldment?

Two sites you need to study, especially the first:

How to Search the Internet - Hannon Library

A Comparison of Online Backpass Cleaning ... - Energy Central

Tips for Posting on CR4:

• Look for answers before you post. Search CR4 or use a search engine to see if you can find the answer to your question.

I think Your only assuming that i didn't try to find it in CR4. But there isn't any thread in CR4 that has explained about this. I meant backpass / back pass for boiler in coal-fired steam power plant

A large utility boiler has a (front pass) furnace, where the tubes "see" the fire with radiative and convective heat transfer. The hot gases travel over the top and down the back pass, where there is primarily convective heat transfer.

where does this term (backpass) first came from?

The University of Hardknocks, perhaps?

Do you have any reference, that states this? (A book/ journal/article)

I may be wrong, I think you will find it come from either Yorkshire or Lancashire boilers of the 19^th century.

One of the two had a back pass (return flue) with a secondary combustion chamber opposite the fire box.

is there any article or journal which i can refer to that defines what back pass is?

I thought I had sent this already. Sorry!

A pass is a straight shot of hot gases, horizontal or vertical, past heat transfer equipment. In a large coal- or trash-burning boiler, the furnace (close to the operator, so "front" pass) has upward gas flow, with larger ash particles falling to a collection hopper. Fly ash is entrained with the gas flow up, over, and down the back pass, through an air preheater, turning the corner toward the stack, hopefully past some pollution control equipment. In an old steam locomotive, the boiler has a single, horizontal pass from the firebox to the stack.

http://www.alstom.com%2FGlobal%2FPower%2FResources%2FDocuments%2FBrochures%2Fpulverised-coal-boiler-two-pass-boilers.pdf

http://www.fulton.com/products/productprofile.php?ptc=&uid=7