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Boilers chemical cleaning circulation with Nitrogen

Dear sir,

can you please explain how can we establish circulation in large natural circulation boilers during chemical cleaning without pumps and with Nitrogen pressure? and how the flow is effected?

Arumugam Ramalingam
construction company - Dammam, eastern, Saudi Arabia
2004

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October 29, 2008

it is a simple process to circulate stored solvent in the boiler without any pump by a process called auto circulation. The circulation is attempted by using nitrogen gas. The circulation will be in the reverse order in relation to regular steaming order.
Provide subs in all the down comers at 1/3rd distance from bottom. Make arrangements to feed nitrogen at regular intervals with vent open. pass nitrogen say for 5 mts and feed through next d\c. give interval for 30 mts. take sample for analysis. repeat till equalisation.
similarly circulate at various stages of operation like rinsing, citric rinse, neutralisation, passivation, etc.
any doubt address

thiruvenkatachari sampath
- Chennai,tamilnadu, India

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Some further questions:
How to inject nitrogen into downcomers?
Do you drill holes and weld connections?
How much nitrogen are you using for a boiler with, let us say, 100 m3 water volume? And at what pressure (reduced?)?

Thank You in advance

Anders Sundström
- Göteborg, Sweden
January 26, 2012