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Patent Searching and Data


Title:
BOILER AND METHOD OF ITS OPERATION
Document Type and Number:
Japanese Patent JPH04143503
Kind Code:
A
Abstract:

PURPOSE: To reduce corrosion in the water tubes in a water wall due to the low NOx combustion by supplying a gas that contains oxygen into a furnace through a hole provided in the water wall when an oxygen partial pressure measurement device that is provided in the water wall near a burner detects that the oxygen partial pressure near the surface of the water wall pipe has become a specified value.

CONSTITUTION: A plurality of burners 3 are installed to a water wall 2 that forms a furnace 1. The water wall 2 is provided with an after-air port 4, secondary air duct 5, and side wall duct 7. The side wall duct 7 is provided with a port 8 that supplies a gas 6a containing oxygen into the furnace 1 and an oxygen sensor 9 which is a means to measure oxygen concentration in the surface layer section of a water wall pipe that will be described below. As the gas 6a that contains oxygen and is supplied from the port 8 into the furnace 1 the secondary air 6 used for the combustion of the burners 3 is branched to be supplied to a branch duct 7. When the partial oxygen pressure becomes below -20atm. a flow rate regulating valve 13 opens at (a) and (b), and the secondary air 6a is supplied into the furnace 1 through the port 8. With this arrangement it is possible to remarkably reduce the high temperature corrosion of the water wall that is caused by the combustion with low NOx.


Inventors:
FUKUDA YUJI
Application Number:
JP26786190A
Publication Date:
May 18, 1992
Filing Date:
October 05, 1990
Export Citation:
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Assignee:
BABCOCK HITACHI KK
International Classes:
F23N5/00; F22B31/00; F22B35/00; F23C99/00; (IPC1-7): F22B31/00; F22B35/00; F23C11/00; F23N5/00
Attorney, Agent or Firm:
Unuma Tatsuyuki