How is Boiler Constructed?

Replies

• 

  Kaustubh Katdare

  Changed the titled of the thread from 'Boiler' to 'How is Boiler Constructed' so that the readers get an idea of what's inside the thread just by reading the title.
• 

  Khushwant

  A boiler used in power plants has many parts. some major parts are furnace, boiler drum, and some other accessories to increase efficiency. These major parts are fabricated before hand and joined together at the given site by various processes like welding. For example the furnace is made of 4 long sections of water wall tubes which provide a space between them for burning of fuel. these 4 walls are brought to site individually and then joined together, hence forming the furnace.
• 

  ikailashrao

  hi vipul,
  Procedure of boiler construction.
  list of material/equipments required:
  [TABLE]
  [TR]
  [TD="class: xl65, width: 209"][/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]STEAM DRUM
  [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]RH PANEL - CONVECTION [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]LH PANEL - CONVECTION [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]REAR PANEL - CONVECTION [/TD]
  [/TR]
  [TR]
  [TD="class: xl67, width: 209"]FRONT/ROOF PANEL-CONVECTION INCLUDING SCREEN [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]RISERS[/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]DOWN COMERS[/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]SUPPORT FOR RDC[/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]SUPERHEATER COILS - PRIMARY[/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]SUPERHEATER COILS - SECONDARY [/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]SUPERHEATER HEADERS [/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]ATTEMPERATOR ASSEMBLY[/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]EVAPORATOR COILS [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]EVAPORATOR HEADERS [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]SUPPORT TUBE & HEADER [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]FINNED ECONOMISER ASSEMBLY [/TD]
  [/TR]
  [TR]
  [TD="class: xl66, width: 209"]ECONOMISER HEADER-LOOSE [/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]ECONOMISER CASING PANELS[/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]PRESSURE PART SUPPORTS[/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]BUCKSTAY [/TD]
  [/TR]
  [TR]
  [TD="class: xl68, width: 209"]DOORS & PEEP HOLES[/TD]
  [/TR]
  [TR]
  [TD="class: xl69, width: 209"]MINERAL WOOL[/TD]
  [/TR]
  [TR]
  [TD="class: xl69, width: 209"]CLADDING[/TD]
  [/TR]
  [TR]
  [TD="class: xl69, width: 209"]INSULATION HARDWARE[/TD]
  [/TR]
  [TR]
  [TD="class: xl69, width: 209"]MINERAL WOOL - PIPING[/TD]
  [/TR]
  [TR]
  [TD="class: xl69, width: 209"]CLADDING - PIPING[/TD]
  [/TR]
  [TR]
  [TD="class: xl69, width: 209"]INSULATION HARDWARE - PIPING[/TD]
  [/TR]
  [TR]
  [TD="class: xl70, width: 209"]DEARATOR TANK[/TD]
  [/TR]
  [TR]
  [TD="class: xl69, width: 209"]INTEGRAL PIPING [/TD]
  [/TR]
  [TR]
  [TD="class: xl71, width: 209"]SPRING HANGERS [/TD]
  [/TR]
  [/TABLE]
  
  
  [TABLE="width: 209"]
  [TR]
  [TD][/TD]
  [/TR]
  [TR]
  [TD]STEAM DRUM
  [/TD]
  [/TR]
  [TR]
  [TD]RH PANEL - CONVECTION
  [/TD]
  [/TR]
  [TR]
  [TD]LH PANEL - CONVECTION
  [/TD]
  [/TR]
  [TR]
  [TD]REAR PANEL - CONVECTION
  [/TD]
  [/TR]
  [TR]
  [TD]FRONT/ROOF PANEL-CONVECTION INCLUDING SCREEN
  [/TD]
  [/TR]
  [TR]
  [TD]RISERS
  [/TD]
  [/TR]
  [TR]
  [TD]DOWN COMERS
  [/TD]
  [/TR]
  [TR]
  [TD]SUPPORT FOR RDC
  [/TD]
  [/TR]
  [TR]
  [TD]SUPERHEATER COILS - PRIMARY
  [/TD]
  [/TR]
  [TR]
  [TD]SUPERHEATER COILS - SECONDARY
  [/TD]
  [/TR]
  [TR]
  [TD]SUPERHEATER HEADERS
  [/TD]
  [/TR]
  [TR]
  [TD]ATTEMPERATOR ASSEMBLY
  [/TD]
  [/TR]
  [TR]
  [TD]EVAPORATOR COILS
  [/TD]
  [/TR]
  [TR]
  [TD]EVAPORATOR HEADERS
  [/TD]
  [/TR]
  [TR]
  [TD]SUPPORT TUBE & HEADER
  [/TD]
  [/TR]
  [TR]
  [TD]FINNED ECONOMISER ASSEMBLY
  [/TD]
  [/TR]
  [TR]
  [TD]ECONOMISER HEADER-LOOSE
  [/TD]
  [/TR]
  [TR]
  [TD]ECONOMISER CASING PANELS
  [/TD]
  [/TR]
  [TR]
  [TD]PRESSURE PART SUPPORTS
  [/TD]
  [/TR]
  [TR]
  [TD]BUCKSTAY
  [/TD]
  [/TR]
  [TR]
  [TD]DOORS & PEEP HOLES
  [/TD]
  [/TR]
  [TR]
  [TD]MINERAL WOOL
  [/TD]
  [/TR]
  [TR]
  [TD]CLADDING
  [/TD]
  [/TR]
  [TR]
  [TD]INSULATION HARDWARE
  [/TD]
  [/TR]
  [TR]
  [TD]MINERAL WOOL - PIPING
  [/TD]
  [/TR]
  [TR]
  [TD]CLADDING - PIPING
  [/TD]
  [/TR]
  [TR]
  [TD]INSULATION HARDWARE - PIPING
  [/TD]
  [/TR]
  [TR]
  [TD]DEARATOR TANK
  [/TD]
  [/TR]
  [TR]
  [TD]INTEGRAL PIPING
  [/TD]
  [/TR]
  [TR]
  [TD]SPRING HANGERS
  [/TD]
  [/TR]
  [/TABLE]
  
  
  steps:
  firstly u r required to fabricate all the support structures and erect those in a levelled area.
  then ground inspection is required for all the boiler equipments by IBR.
  then erection of equipments one after another,
  this is not a simple equipment erection.
  u r always required to check the welding joints i.e header to header joints bcoz the IBR inspector will check it through all the phases.
  wen all the parts are erected, the testing is done.
  final step is commissioning.
  now the plant is ready for use.
  
  this is a brief procedure.
• 

  Zoodie

  Although this is a very brief procedure, yet this is very useful for the sake of understanding. And I hope that would be very helpful too. This is good to make base to any boiler making.
  #-Link-Snipped-#
• 

  annmary

  Hi,
  
  A boiler is a closed vessel in which water or other fluid is heated. The heated or vaporized fluid exits the boiler for use in various processes or heating applications.The pressure vessel in a boiler is usually made of steel (or alloy steel), or historically of wrought iron.Stainless steel is virtually prohibited (by the ASME Boiler Code) for use in wetted parts of modern boilers, but is used often in superheater sections that will not be exposed to liquid boiler water.Although this is a very brief procedure, yet this is very useful.To know more about boiler please click the link Search Results For Products By Name: [ boiler ]
• 

  Aaron Racheed

  Hey,
  
  In the 20th century, design practice instead moved towards the use of steel, which is stronger and cheaper, with welded construction, which is quicker and requires less lab our.cast iron may be used for the heating vessel of domestic water heaters. Although such heaters are usually termed "boilers" in some countries, their purpose is usually to produce hot water, not steam, and so they run at low pressure and try to avoid actual boiling. The brittleness of cast iron makes it impractical for high pressure steam boilers.Although this is a very brief procedure, yet this is very useful.To know more about Accessories for Boilers Suppliers @ ProcessRegister.comAccessories for Boilers,Air Atomizing Nozzles Suppliers & Manufacturers.
• 

  rebellionofrebel

  Boiler is a fired pressure vessel. It is used for Steam generation. Normally boiler is a general term for any pressure vessel that is used to generate steam . The correct term is Steam Generator. A boiler designed for Power plants is much different from that used in process industries like oil refineries , textiles, breweries ,etc. The bolier parts mentioned in one of the above replies is for a power boiler.. i.e. the one used for power generation. Normally ASME Section VIII deals with pressure vessel design . The piping part is governed by B31. 1 for power plants, etc.
  The bolier is designed for different conditions based on its usage. This defines the bolier load in terms of Steam rate, fuel usage ,etc...
  The boiler is also governed by the different acts like The Boiler Act (in India) , etc... The boiler is certified by boiler inspectors , by hydrotests ,etc..
  The boiler is designed for implosion for safety of personnel working in the vicinty and also for the safety of other equipments present in its vicinity !!!
• 

  Ramani Aswath

  rebellionofrebel

  Boiler is a fired pressure vessel. The boiler is designed for implosion for safety of personnel working in the vicinty and also for the safety of other equipments present in its vicinity !!!

  This is the first time I hear that a pressure vessel can IMPLODE.
  
  How is this feat accomplished?
• 

  akash6448

  Solve This...
  
  A and B do a work together in 6 days. If A works alone then it takes 10 days, then how many days B takes to complete that work?
• 

  rebellionofrebel

  Implosion is achieved by keeping the pressure inside below our Atm pressure.. this makes sure that things remain inside .. Moreoever, it helps the operation engineer to have a peek inside without the danger of fire blasting out on his face from those small windows which are the size of 7 cm by 20cms .. as observed by me in the Power Boilers in India ...
• 

  Ramani Aswath

  rebellionofrebel

  Implosion is achieved by keeping the pressure inside below our Atm pressure.. this makes sure that things remain inside ..

  Very illuminating. It is sobering to know that high pressure boilers operate with vacuum inside them.
  I fail to understand how steam below atmospheric pressure runs turbines and other stem engines.
• 

  rebellionofrebel

  Hold on!!!!!! Steam is in the tubes.. We are talking of the furnace part of the boiler where the tubes run along the walls on the sides.. I m talking about low pressure in the furnace part that is external of the tubes but inside the bolier area!!!! Steam never goes below atm press inside boiler.. For a 5ooMW power plant Steam inlet to Turbine is at 160 bar.... The boiler drum pressure is approx 175 bar..
• 

  Ramani Aswath

  The fire box and flue tubes of boilers are not the ones that burst. It is the steam containing part that bursts. There can be collateral damage by fire incidental to the steam burst. It is the high heat capacity expanding steam that causes damage.
• 

  rebellionofrebel

  flues tubes???? There are no flue tubes.. There is windbox through which the air enters Furnace via coal mills (courtesy PA fans ).. Normally the flue gas passes through out the boiler section and through Goose neck and is sucked out by ID fans!!!!THe steam tubes if burst then the collateral damage is normally inside the boiler area !!! It is the furnace part where the fuel is burnt where there is the need for low pressure.. !!! The low pressure helps in keeping this under control incase of any pressure surges inside the furnace either due to water tubes bursting or any other anomaly..
• 

  Ramani Aswath

  We seem to be talking about different matters. There is no attempt here to win any brownie points. I yield and close this discussion from my side agreeing that you are probably right in the context from which you are arguing.
• 

  rebellionofrebel

  It is my sincere apologies if you felt that i was trying to win some brownie points!!! Sir, I assure you my intentions were not what you think. Since you had first asked me how the pressure was low and thereon i tried to explain you the different elements that go inside boiler which makes it necessary to keep vacuum inside furnace section. My humblest apologies....
  
  To add to our discussion, all our power boilers are normally fixed from topside. the boiler is left hanging from ground side to allow for expansion. even when you have the ash chamber, the boiler is instralled at a particular hieght to allow for expansion.
  also to add to our healthy diccussion, the boiler drum is shielded from the fire inside the furnace. infact there is a physical partition between them.
• 

  Ramani Aswath

  rebellionofrebel

  It is my sincere apologies if you felt that i was trying to win some brownie points!!!
  also to add to our healthy diccussion, the boiler drum is shielded from the fire inside the furnace. infact there is a physical partition between them.

  I was referring to my not wanting to win brownie points, not you. However, there is absolutely no call for apologies. Even in a forced draft boiler the furnace side pressure is near atmospheric. Because of dissolved solids, concentration overpotential, crevice corrosion and thermal cycling along with stress corrosion cracking the steam pressure side of the boiler gives way and creates injuries or death. As you say, proper design of the fuel side can mitigate this to some extent.
  Poor maintenance is often the reason for failure.
  I see that I was a bit brusque in my last response. I am not as a rule. Sorry for that.
  
  Are you working on steam power generation or something like that?
• 

  ISHAN TOPRE

  I guess the construction of boiler is simple. Of course I do not have any experience of working in it apart from the small boilers that I have seen in our college Thermal laboratory ( Work shop whatever!)
  
  These are the threads that fascinated me towards CE. The guy is Khaled Hamza from Cairo, Egypt don't know where he lives now.
  
  Have a look at the thread that he started.
  1. #-Link-Snipped-#
  Also see
  
  2. #-Link-Snipped-#
• 

  rebellionofrebel

  No apologies needed sir... I guess we both had a classic case of misunderstadning between us. Sir, I was working in the main control room of a 500MW thermal power plant. My speciality was on turbine side, but then we needed to know the whole plant on our fingertips in case of any mishaps!!!
• 

  akpower

  I am a power engineer.I have gone through the discussion between Mr.Bioramani Sir & Mr Rebellionofrebel.While replying to issue of how boiler is constructed, both of them entered intricacies of explosion/implosion.Steam boiler being a pressure vessel is constructed keeping safety of operating personnel.Older versions were operating at lesser pressures & temperatures and mostly from nearby panels or firing floor.With developments in metallurgy( particularly alloy steel), the same parameters are increasing to meet supercritical criteria.The sophistication in instrumentation & digital technology permits the boiler operation from remote control room from which even the boiler is not visible. Deviation from permissible parameters spounds alarms for operation engineer. Therefore control of parameters & safety of personnel are both taken care of. However I know for certain that accident may take place.Explosion is phenomenon of improper coal combustion which may generate shockwaves.Implosion is not taking place in a boiler in its true sense.It may cause due to high negative pressure in furnace and weak waterwall tube structure. Tube leakages a common phenomena in boilers may be due to various reasons like1)thinning of tubes 2)erosion 3)corrosion 5)hydrogen embrittlement 6)oxidation 7 to name a few.
• 

  rebellionofrebel

  Views accepted Comrade!!!! I concur with you !!!!!