How Large Boiler Drums are Manufactured

Boilers in power plants and process plants have large drums to house the steam-water mixture, to hold large quantity of water required for steam generation, and ensure steam quality. Drums weigh anywhere 100 to 250 tons with very high thickness. Manufacturing drums need special machines and process.

Power and process boilers have a large cylindrical vessel called the Drum. Early boilers had as many as four drums, but present day boilers have either one or two drums. A 210 MW boiler drum weighs about 130 tons and a 500 MW boiler drum about 250 tons. The drums of bi-drum boilers can be anywhere near 100 tons. The boiler drums have large stubs welded, many instrument tapings, safety valve stubs, and internals to maintain the quality of steam and distribute the feed wate, and a facility to dose the chemicals uniformly across the length of the drum. Boiler drums are generally made of carbon steel of boiler quality plates of varying thickness depending on the design pressure of the boiler.

Stages of manufacturing drum

Plate quality check by ultrasonic test
Review ultrasonic test report and steel supplier test report
Move plate to heating furnace and heat to 850 - 870 deg C. Use incremental pressing in a 6000 or 8000 ton hydraulic–beam press and work it to get the shell shape based on the shell inside diameter
Cold press the plate to the final specified shape when plate is below 130 deg C, but not below room temperature
The shell is moved to a special weld bevel machine for beveling the ends
Tack weld the counterpart (wrapper) shell which is slightly thinner
Weld longitudinal seam by submerged-arc process in thin layers in succession maintaining a preheat of 150 deg C
Back gouge the inner side after the outer weld is completed to a sound metal using electric arc process
The weld is finished using the automatic submerged-arc welding
The shell is welded 20 % on each side alternatively to control distortions of the shell
Grind the longitudinal weld flush both inside & outside and do magnetic particle test
Do radiography of the weld using a linear accelerator (4MeV or above)
If necessary repair using a low hydrogen electrode at 150 deg C preheat
Re-radiograph after repair till test results are satisfactory
All nozzles and nipples are drilled in the drum shell
Weld the nozzles and nipples by manual arc welding using low hydrogen electrode with 150 deg C pre heat
Join the first two shells with a girth seam and grind the weld and do magnetic particle test and radiography of weld to ensure weld quality
Weld the hemispherical shell to the end of the shell always maintaining 150 deg C preheat while welding and do magnetic particle test and radiography of weld
Each of the two assemblies are stress relieved at 605 deg C plus / minus 5 deg C
Put the internal structures in place and then the final girth weld is made maintaining preheat of 150 deg C. This weld is locally stress relieved, followed by magnetic particle test of all welds
Finally paint the outer surface and the drum is ready for shipping to the site.
 

Keyword: Industry steam boiler,Large Boiler Drums, Boiler Manufacturer

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Packaging & Delivery

Packaging Detail:Wooden box package of How Large Boiler Drums are Manufactured

Delivery Detail:20-40 days after payment

FAQ about industrial steam boiler

Why choose ZG as industrial steam boiler manufacturer?

We have over 70 years' experience of industrial steam boiler and autoclave, and we have a professional installation and after-sales staff for products.Take advantage of the most economical way to improve efficiency and operating flexibility, Get substantial savings on your fuel costs,Reduce all emissions for each K/W of electricity generated, including CO2.

How about the quality of How Large Boiler Drums are Manufactured?

Our industrial steam boiler manufactured strictly according to national and international standard. our products have approved ASME, IBR, ISO9001-2008, etc

All our company's products are 100% factory inspected to ensure the high quality.

We provide one year quality warranty service, please rest assured purchase.

Our Service

ZG service ensures that this will not happen. During installation of industrial steam boiler, 1-2 experienced engineering and technical personnel will be sent for the site representative for technical tests and installation instructions free of charge; processing the various problems arising in the course timely while installing.

Industrial Steam Boiler Company Information--- ZG Boiler

Established:In 1945

Number of Employees:above 1500 People

Our products:industrial horizontal steam boiler and hot water boiler(biomass boiler, gas boiler, oil boiler, coal boiler, etc), CFB boiler, power plant boiler, waste heating recovery boiler, Pressure Vessel(AAC autoclave, Curing tank,etc )

Factory Size (Sq.meters):400,000 square meters

Factory Location:Factory 1: Zhengzhou,,Henan, China. Factory 2: Xingyang,Henan,China

Number of R&D Staff:376 people

Our Trade & Market

Export Percentage:30-40%

Total Annual Sales Volume:US$100 Million

Main Market:South America(Colombia, Venezuela, Guyana, Suriname, Ecuador, Peru, Brazil, Bolivia, Chile, Paraguay, Uruguay, Argentina and French Guiana), North America(Bahamas, Canada, Costa Rica, Cuba, El Salvador, Guatemala, Honduras, Haiti, Jamaica, Mexico, Nicaragua, Panama), Eastern Asia(Mongolia / Russia / North Korea / South Korea / Japan), Oceania(Australia, New Zealand, Fiji), Mid East(Bahrain, Egypt, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, UAE and Yemen, Palestine, Algeria, Libya, Morocco, Tunisia and Sudan, Mauritania and Somalia), Africa(Egypt, Sudan, Libya, Tunisia, Algeria, Morocco, Ethiopia, Somalia, Kenya, Tanzania, Sierra Leone, Liberia, Cote d'Ivoire, Ghana, Togo, Niger, Nigeria, Cameroon, Gabon, Congo (Brazzaville), Zambia, Zimbabwe, Angola, Mozambique, Botswana, Namibia, South Africa), South Asia(Nepal, Bhutan, India, Pakistan, Bangladesh, Sri Lanka, Maldives) Southeast Asia(Vietnam, Laos, Cambodia, Thailand, Myanmar, Malaysia, Singapore, Indonesia, Brunei, the Philippines, East Timor) Domestic Market(China)

Source: http://www.zgsteamboiler.com/news/How-Large-Boiler-Drums-are-Manufactured.html

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