The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 22, 2001

Filed:

Feb. 18, 2000
Applicant:
Inventor:

Shigeaki Yasui, Nagoya, JP;

Assignee:

Rinnai Kabushiki Kaisha, Aichi-ken, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F23N 5/24 ;
U.S. Cl.
CPC ...
F23N 5/24 ;
Abstract

An orifice is disposed in an intake tube for developing a pressure difference across the orifice, i.e., portions of the intake tube which are positioned upstream and downstream of the orifice. An upstream connection pipe and a downstream connection pipe have respective ends connected to the intake tube and opening into the intake tube respectively upstream and downstream of the orifice, and respective opposite ends connected to a pressure sensor. The pressure sensor detects the pressure difference between the pressure of combustion air in the upstream connection pipe and the pressure of combustion air in the downstream connection pipe. If a change from a pressure value prior to combustion, which is a pressure value detected by the pressure sensor when the combustion fan is stopped before a burner starts burning a fuel gas, to a pressure value in combustion, which is a pressure value detected by the pressure sensor while the fuel gas is being combusted by the burner, becomes smaller than a threshold value, then the combustion of the fuel gas by the burner is stopped.


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