JP2008157620A - Method of controlling combustion of burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems of conventional methods of controlling the combustion of burners wherein since stable combustion is provided by a burner by adjusting flow control valves inserted into branch pipes for feeding a gas and an air to the burner, respectively, a large labor and a long time are required for the adjustment. <P>SOLUTION: In this method of controlling the combustion of a burner, an orifice is inserted in a gas branch pipe and an air branch pipe. A gas header feeds the gas and the air to the burner through the branch pipes. The gas and the air of generally predetermined quantities are fed to the air header through the gas flow control valve and the air flow control valve until the pressure in the header is increased to a generally predetermined value. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a burner combustion control method, in particular, burner combustion for adjusting the gas amount and air amount for each of a number of burners installed in an atmosphere heat treatment furnace to realize stable combustion of a plurality of burners. It relates to a control method.

When adjusting a large number of burners installed in an atmospheric heat treatment furnace or the like, conventionally, a gas orifice and a gas adjustment valve are provided for each branch pipe supplied to each burner from the gas header, and the pressure reduction value by the orifice of each burner The adjustment valve was adjusted so that the (orifice differential pressure) was the same. Also, for adjusting the amount of combustion air, an air orifice and an air adjustment valve are provided for each branch pipe supplied from the air header to each burner, so that the O ₂ (oxygen) component in the combustion exhaust gas of each burner is the same. Had adjusted the air adjustment valve. By these adjustments, stable combustion can be obtained even when a plurality of burners are provided.

  FIG. 2 shows an apparatus for carrying out such a conventional burner combustion control method, wherein 1 and 2 are gas headers and air headers, respectively, 3 is a number of burners installed in an atmospheric heat treatment furnace, and the like. Is a gas branch pipe and an air branch pipe communicating with each of the burners 3 between the gas header 1 and the air header 2, 6 is a gas supply source pipe of the gas header 1, and 7 is an air supply source pipe of the air header 1. , 8 is an air blower serving as an air supply source connected to the air supply source pipe 7, 9 is a proportional valve inserted in the gas supply source pipe 6, and 10 and 11 are the gas header 1 and the air header 2 respectively. The pressure gauges 12 and 13 are connected to the gas branch pipe 4 in series, and the gas orifice and the gas regulating valve 14 and 15 are respectively inserted in series to the air branch pipe 5. And a air orifice and the air adjustment valve.

In the conventional burner combustion control method, when adjusting the combustion of the multiple burners 3, a gas orifice 12 and a gas adjustment valve 13 are provided for each gas branch pipe 4 supplied from the gas header 1 to each burner 3. The gas regulating valve 13 is adjusted so that the pressure applied to each burner 3 through the orifice 12 is the same. Also, for adjustment of the amount of combustion air, an air orifice 14 and an air adjustment valve 15 are provided for each air branch pipe 5 supplied from the air header 2 to each burner 3, and O ₂ ( The air adjusting valve 15 is adjusted so that the components (oxygen) are the same, and by these adjustments, stable combustion can be obtained even when a plurality of burners are provided.

However, as described above, in the conventional combustion adjustment method, the pressure applied to the gas through the orifice for each burner is made the same by the gas and air adjustment valves provided for each branch pipe of each burner. The air is adjusted so that the combustion state of each burner is the same while measuring the O ₂ component of the exhaust gas, so it takes a lot of labor and time to repeat the measurement and adjustment for each. I needed it.

In particular, the adjustment of the air amount is to adjust the air amount of each burner one by one, and when the adjustment is completed, the phenomenon that the measured O ₂ value of the exhaust gas of the burner that was adjusted first changes will occur. Time is particularly big. Further, since an air supply source having a relatively large pressure fluctuation such as an air blower is usually used, the adjustment thereof is more difficult.

  Furthermore, in the conventional method, the adjustment error becomes large due to its complexity, and there are inconveniences such as shortening the life of the burner and the like.

  Patent documents 1 to 3 are also known.

Japanese Patent Laid-Open No. 03-087512 Japanese Patent Laid-Open No. 04-369316 Japanese Patent Laid-Open No. 10-267262

  Each of the above Patent Documents 1 to 3 has a control arithmetic device for adjusting the flow rate of gas or air, a controller, a combustion air flow control valve, and the like. These control devices have conventionally required a great deal of labor and time manually.

An object of the present invention is to obtain a burner combustion control method which eliminates this inconvenience and can be easily adjusted by anyone.

  As a result of intensive investigation and research in order to solve the above problems, the inventors of the present invention require the complicated adjustment as described above, particularly because the supply pressure of the air blower varies depending on the flow rate used in each air branch pipe. However, if the air supply pressure to the air supply source pipe is adjusted to a substantially predetermined value by inserting the adjustment valve to the common air supply source pipe without inserting the adjustment valve in each air branch pipe, respectively. It has been found that no complicated adjustment is required, and that the accuracy of the value to be reduced by the orifice is ± 5% or less, preferably ± 2.5% or less. The present invention has been made based on such knowledge.

  The burner combustion control method of the present invention is a step of flowing gas and air of a predetermined pressure from a gas supply source pipe and an air supply source pipe to a gas header and an air header, respectively, via a gas flow rate adjustment valve and an air flow rate adjustment valve, respectively. And a process of flowing gas and air from the gas header and the air header to the gas branch pipe and the air branch pipe connected to each burner via the gas orifice and the air orifice, respectively, whose accuracy of the decompression value is ± 5% or less. It is characterized by comprising.

  According to the burner combustion control method of the present invention, each of the header pressures is adjusted to a predetermined value by the flow rate adjustment valve without individually adjusting the flow rates of the gas and air in the branch pipes of the multiple burners. The flow rate of gas and air to the burner can be adjusted at the same time. Even if the number of burners increases, only one gas flow adjustment valve and one air flow adjustment valve need to be adjusted. There is a big benefit that makes it easy.

  In addition, when an open / close valve is inserted in each branch pipe, there is an advantage that only a necessary burner can be burned.

  Embodiments of the present invention will be described below with reference to the drawings.

  In the burner combustion control method of the present invention, as shown in FIG. 1, the accuracy of the value to be reduced to the gas branch pipe 4 and the air branch pipe 5 connected to each burner 3 is ± 5% or less, preferably ± 2.5. % Gas flow adjusting valve 18 inserted into gas supply source pipe 6 by flowing gas and air from gas header 1 and air header 2 through high-performance orifice 16 and high-performance orifice 17 having a flow rate regulation function of% or less. The pressure of the gas and air supplied to the gas header 1 and the air header 2 are adjusted to be substantially predetermined values by the air flow rate adjusting valve 19 inserted in the air supply source pipe 7, respectively.

  According to the burner combustion control method of the present invention, the highly accurate gas orifice and air orifice are installed, and the gas flow rate adjusting mechanism (valve) provided in each of the gas supply source pipe and the air supply source pipe, and Only by adjusting the air flow regulator (valve), the problem of stable combustion and difficulty of adjustment can be solved, and the extremely simple configuration and simple adjustment of the valve make it possible to adjust each burner. The combustion state can be made the same.

It is explanatory drawing of the apparatus for enforcing the combustion method of the burner of this invention. It is explanatory drawing of the apparatus for enforcing the combustion method of the burner by a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas header 2 Air header 3 Burner 4 Gas branch pipe 5 Air branch pipe 6 Gas supply source pipe 7 Air supply source pipe 8 Air blower 9 Proportional valve 10 Pressure gauge 11 Pressure gauge 12 Gas restriction orifice 13 Gas flow control valve 14 Air restriction Orifice 15 Air flow rate adjustment valve 16 High performance orifice 17 High performance orifice 18 Gas flow rate adjustment valve 19 Air flow rate adjustment valve

Claims (1)

Flowing gas and air at a predetermined pressure from the gas supply source pipe and the air supply source pipe to the gas header and the air header, respectively, via the gas flow rate adjustment valve and the air flow rate adjustment valve, respectively;
The gas branch pipe and the air branch pipe connected to each burner comprise the steps of flowing gas and air from the gas header and the air header, respectively, through the gas orifice and the air orifice whose accuracy of the reduced pressure is ± 5% or less. A burner combustion control method characterized by the above.

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