Furnace coils replacement

Furnace coils replacement

Ethylene Furnace Coils

Coil working at high temperature weakens the coil for maintenance The coil is replaced every 5 years or 3 years. And it's also the manufacturer's standard.
* Incoloy alloy material is commonly used for high-temperature coils in the furnace radiant section.

  Coil replenishment Steps

> This is hot work and confined space activity so use work permits that are necessary.

* Furnace-connected inlets/outlets are ensured proper isolation and do the blinding activity. https://maintenance4you.blogspot.com/2021/03/blinding-de-blinding.html
* Open all peep side doors.
* Inside the radiant section arrange the 24 volts light.
* Install the air ventilation system.
* Check the internal atmosphere. 
* In-side the radiant section build the scaffolding. ( for the third party)
* Remove the arch cover or arch seal.
* Lock all spring hangers.
* Heng the old existing coil by a chain-block.
* Put the 80 or 100-ton crane in the right place.
* Cover the hot work area with a fire blanket.
* Cut the old coil from the top weld joint as per the client or QC information (using the grinding machine)
* Remove coil bundle or one by one as facility using rigging support.
* Remove the refractory block ( for the third party)
* Old existing tube cut area performs the bevel activity by grinding or using a Pneumatic/Electrical beveling machine.
* After beveling perform DPT ( Dye Penetrant Test)
 ( Any type of crack or any type of pinhole found during the DPT test requires immediate rectification)
* Erect and install the new coil bundle inside the radiant section. (using rigging support crane and chain block) 

* To measure and ensure proper gap fit-up when processing the fit-up, use a piece of gap rod or filler rod. Quickly weld until 3 to 4 mm gap and ID high/low tube is installed and call for a fit-up inspection. (When you do the  fit up the tube, it is necessary to follow the rules of WPS) 
* When a fit-up inspection is done, start welding as per WPS in welding, (Welding Procedure Specification)
* After completion of welding route and hot pass, let it cool down and obtain DPT. (If any pinhole or any creak is found in welding during the DPT, fix it immediately)  
* Finish the Welding By Filling And Capping. and properly clean the weld joint to obtain the final DPT.
* Finally, arrange for an RT inspection of all welded joints. (Radiographic test) 
* Perform the anchor bolt welding as the refectory team required. ( Refectory support activity)
* Re-install the new refractory block in the arch area.
* Re-Install the arch cover or cover plate and properly tight the bolt and nuts.
* Un-lock all spring hangers and do a proper alignment.
* Remove all scaffolding from the radiant section.
* Remove all light and material from the radiant section.
* Confirm with QC and Close all furnace manways & peep doors.
* Remove all blinds from the furnace inlet/out.
* Remove the crane and other equipment from the work area and shift laydown.
* Perform good housekeeping and hand over the furnace.

Material required

1- Crane 80 to 100 tons.
2- Air compressor.
3- Diesel generators 150 to 200KW
4- Portable Welding machine 15 nos.
5- If required Tower light.
6- Air Hoist 3 tons 3 nos. or monorail 
7- Air manifold 
8- Chain block 2 ton to 5 Tons 50 nos
9- Lifting tools ( web ceiling belt, D shackle )
10- Welding Material as par WPS
11- Grinding/Pencil grinder, Beveling machine.
12- Air hose
13- Air Remover/Venture
13- Hand tools ( spanner)
14- 24 volts Light 

Furnace Internal view

Some Examples of coil erection and after erection internal view

Note

I am doing this work as my personal experience in the description, it has nothing to do with any private company or any organization, my purpose is only to pass my experience to others if anyone has any kind of objection, So you tell me or email and if you liked this information please write in comment

Thank you